Hydrocephalus

Idiopathic normal pressure hydrocephalus Magnetic resonance imaging

Idiopathic normal pressure hydrocephalus Magnetic resonance imaging

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see Evans index

see Callosal angle

see Cingulate sulcus sign

see DESH

1. prerequisite: ventricular enlargement without block (i.e., communicating hydrocephalus). MRI excels at ruling out obstructive hydrocephalus due to aqueductal stenosis

2. features that correlate with favorable response to shunt. These features suggest that the hydrocephalus is not due to atrophy alone. Note: atrophy / hydrocephalus ex vacuo, as in conditions such as Alzheimer’s disease, lessens the chance of, but does not preclude responding to a shunt (cortical atrophy is a common finding in healthy individuals of advanced age 1))

a) periventricular low density on CT or high intensity on T2WI MRI: may represent Transependymal edema. May resolve with shunting

b) compression of convexity sulci (as distinct from dilatation in atrophy). Note:focal sulcal dilation may sometimes be seen and may represent atypical reservoirs of CSF, which may diminish after shunting and should not be considered as atrophy 2).

c) rounding of the frontal horns

Other helpful findings in iNPH that require MRI

1. Japanese guidelines 3) for iNPH also identify the following features:

a) DESH hydrocephalus with enlarged subarachnoid spaces primarily in the Sylvian fissure and basal cisterns and effacement of the subarachnoid space over the convexity (so-called “tight high convexity”).

In comparison, dilated subarachnoid space in the high convexity is suggestive of atrophy

b) ventricular enlargement in iNPH deforms the corpus callosum,including:

● upward bowing and thinning (best appreciated on sagittal MRI)

● impingement on the falx, producing an acute callosal angle (≤ 90°, demonstrated on a coronal MRI perpedicular to the AC-PC line , passing through the posterior commissure (PC)

2. phase-contrast MRI may demonstrate hyperdynamic flow of CSF through the aqueduct Although some patients improve with no change in ventricles, clinical improvement most often accompanies reduction of ventricular size.

Marked hydrocephalus affecting the lateral ventricles, although without clear signs of transependymal edema, but with loss of volume of the brain parenchyma from chronic chronology.

In the sagittal volumetric T2 sequence, there is no clear occupation of the cerebral aqueduct, also observing the passage of cerebrospinal fluid through the aqueduct. He also appreciates flow artifact on T2 in the 3rd ventricle. The 3rd ventricle presents a slight increase in caliber with the 4th ventricle of normal size, however, the increase in the 3rd ventricle is much less than the lateral ventricular dilatation. Signs of chronic small vessel ischemic zone distributed in both cerebral hemispheres. A small area of ​​encephalomalacia and right occipital gliosis due to sequelae of an old ischemic infarction.

NPH is characterized by an ongoing periventricular neuronal dysfunction seen on MRI as periventricular hyperintensity (PVH). Clinical improvement after shunt surgery is associated with CSF changes indicating a restitution of axonal function. Other biochemical effects of shunting may include increased monoaminergic and peptidergic neurotransmission, breakdown of blood brain barrier function, and gliosis 4).

An MRI-based diagnostic scheme used in a multicenter prospective study (Study of Idiopathic Normal Pressure Hydrocephalus on Neurological Improvement [SINPHONI]) appears to suggest that features of disproportionately enlarged subarachnoid-space hydrocephalus (DESH) are meaningful in the evaluation of NPH 5).

Phase contrast magnetic resonance imaging

see Phase contrast magnetic resonance imaging for idiopathic normal pressure hydrocephalus.

Diffusion-weighted imaging

Diffusion-weighted magnetic resonance imaging (DWI) 6) is used generally in the diagnosis and treatment of various neurodegenerative diseases. The apparent diffusion coefficient (ADC) of the brain, calculated from DWI data, is overestimated because of the effect of bulk motion (rigid body motion caused by the brain pulsation).

Arterial spin labelled imaging

see Arterial spin labelled imaging for idiopathic normal pressure hydrocephalus.

Resting-state functional magnetic resonance imaging

Resting-state functional magnetic resonance imaging for idiopathic normal pressure hydrocephalus

1)

Schwartz M, Creasey H, Grady CL, et al. Computed Tomographic Analysis of Brain Morphometrics in 30 Healthy Men, Aged 21 to 81 Years. Ann Neurol. 1985; 17:146–157
2)

Holodny AI, George AE, de Leon MJ, et al. Focal Dilation and Paradoxical Collapse of Cortical Fissures and Sulci in Patients with Normal-Pressure Hydrocephalus. J Neurosurg. 1998; 89: 742–747
3)

Mori E, Ishikawa M, Kato T, et al. Guidelines for management of idiopathic normal pressure hydrocephalus: second edition. Neurol Med Chir (Tokyo). 2012; 52:775–809
4)

Tullberg M, Blennow K, Månsson JE, Fredman P, Tisell M, Wikkelsö C. Ventricular cerebrospinal fluid neurofilament protein levels decrease in parallel with white matter pathology after shunt surgery in normal pressure hydrocephalus. Eur J Neurol. 2007 Mar;14(3):248-54. PubMed PMID: 17355543.
5)

Hattori T, Ito K, Aoki S, Yuasa T, Sato R, Ishikawa M, et al: White matter alteration in idiopathic normal pressure hydrocephalus: tract-based spatial statistics study. AJNR Am J Neuroradiol 33:97–103, 2012
6)

Moseley ME, Cohen Y, Mintorovitch J, Chileuitt L, Shimizu H, Kucharczyk J, Wendland MF, Weinstein PR. Early detection of regional cerebral ischemia in cats: comparison of diffusion- and T2-weighted MRI and spectroscopy. Magn Reson Med. 1990 May;14(2):330-46. doi: 10.1002/mrm.1910140218. PMID: 2345513

Ventriculoperitoneal Shunt Complications

Ventriculoperitoneal Shunt Complications

see External ventricular drainage complications

see also Cerebrospinal fluid shunt complications.

Ventriculoperitoneal shunt is the most common treatment to manage hydrocephalus; It is unfortunately burdened by up to 25% of complications. The peritoneal approach may expose patients to many complications.

Patients with a ventriculoperitoneal shunt tend to develop epidural fluid accumulation after cranioplasty and also have a higher frequency of syndrome of the trephined after bone flap removal. Thus treatment of patients with postcranioplasty infection and a VP shunt is often challenging.

The management of ventriculoperitoneal shunt complication or failure is a common problem in neurosurgical practice. On occasion, extraperitoneal sites for CSF diversion are required when shunting to the peritoneal cavity has failed after multiple attempts.

Complications frequently associated with a VP shunt: includes shunt obstruction, infection, overdrainage of CSF, and perforation of the gastrointestinal tract, gallbladder, vagina, and abdominal wall at the umbilicus… 1).

Despite procedural and equipment advances, the procedure it is accompanied by frequent complications and malfunctions. Some studies have shown an overall shunt failure rate as high as 59%, with the majority of failures occurring within the first 6 months after shunt placement 2).

Endoscopic placement of ventriculoperitoneal (VP) shunt catheters in pediatric patients has been increasingly used in an attempt to minimize the unacceptably high rates of revision. Although this procedure carries an increased expense, there is currently no evidence to support an improved long-term outcome.

Endoscopic assisted ventricular catheter placement decreased the odds of proximal obstruction but failed to improve overall shunt survival in a 6 year experience 3).

Diagnosis

The evaluation of children with suspected ventriculoperitoneal shunt (VPS) malfunction has evolved into a diagnostic dilemma. This patient population is vulnerable not only to the medical risks of hydrocephalus and surgical complications but also to silent but harmful effects of ionizing radiation secondary to imaging used to evaluate shunt efficacy and patency. The combination of increased medical awareness regarding ionizing radiation and public concern has generated desire to reduce the reliance on head computed tomography (CT) for the evaluation of VPS malfunction. Many centers have started to investigate the utility of low dose computed tomography and alternatives, such as fast magnetic resonance imaging for the investigation of VP shunt malfunction in order to keep radiation exposure as low as reasonably achievable.

A pilot study demonstrates that utilization of limited head CT scan in the evaluation of children with suspected VP shunt malfunction is a feasible strategy for the evaluation of the ventricular size 4).

In the study of Afat et al., low-dose computed tomography (LD-CT) provides excellent sensitivity and higher diagnostic confidence with lower radiation exposure compared with radiographic shunt series (SS) 5).

Ventriculoperitoneal shunt infection

see Ventriculoperitoneal shunt infection.

Ventriculitis

Intraventricular administration of proper antibiotics is a reliable and effective way to treat ventriculitis associated with ventriculoperitoneal shunts.

Vancomycin is the preferred antibiotic for ventriculitis, but other kind(s) of some antibiotics are necessary in a few patients in addition to or instead of vancomycin 6).

Ventriculoperitoneal shunt malfunction

Ventriculoperitoneal shunt overdrainage

see Ventriculoperitoneal shunt overdrainage

Ventriculoperitoneal shunt obstruction

see Ventriculoperitoneal shunt obstruction

Shunt calcification

see Shunt calcification

Abdominal complications

see Ventriculoperitoneal shunt abdominal complications.

Silicone allergy

Ventriculoperitoneal shunt complications have rarely been attributed to silicone allergy, with only a handful of cases reported in literature. The classic presentation of allergy to silicone ventriculoperitoneal shunt, i.e., abdominal pain with recurrent skin breakdown along the shunt tract, is nonspecific and difficult to distinguish clinically from other causes of shunt-related symptoms. It can be diagnosed by detection of antisilicone antibodies and is treated with removal of the shunt and replacement, if needed, with a polyurethane shunt system.

Kurin et al. report the first case of suspected silicone allergy presenting as clinical peritonitis without overt colonic perforation 7).

Progression of Normal-Tension Glaucoma 8).

Case series

Merkler et al., performed a retrospective cohort study of adult patients hospitalized at the time of their first recorded procedure code for VPS surgery between 2005 and 2012 at nonfederal acute care hospitals in California, Florida, and New York. We excluded patients who during the index hospitalization for VPS surgery had concomitant codes for VPS revision, CNS infection, or died during the index hospitalization. Patients were followed for the primary outcome of a VPS complication, defined as the composite of CNS infection or VPS revision. Survival statistics were used to calculate the cumulative rate and incidence rate of VPS complications.

17,035 patients underwent VPS surgery. During a mean follow-up of 3.9 (±1.8) years, at least one VPS complication occurred in 23.8% (95% CI, 22.9-24.7%) of patients. The cumulative rate of CNS infection was 6.1% (95% CI, 5.7-6.5%) and of VPS revision 22.0% (95% CI, 21.1-22.9%). The majority of complications occurred within the first year of hospitalization for VPS surgery. Complication rates were 21.3 (95% CI, 20.6-22.1) complications per 100 patients per year in the first year after VPS surgery, 5.7 (95% CI, 5.3-6.1) in the second year after VPS surgery, and 2.5 (95% CI, 2.1-3.0) in the fifth year after VPS surgery.

Complications are not infrequent following VPS surgery; however, the majority of complications appear to be clustered in the first year following VPS insertion 9).

Case reports

2015

A extremely rare and potentially severe complication of vesical calculi formation on the slit valves of distal end of VP shunt which erosively migrated into the urinary bladder. Suprapubic cystolithotomy performed, peritoneal end of the tube found to be eroding and entering into the bladder with two calculi firmly stuck to slit valves in the distal end of the tubing were removed. Shunt was functional, therefore, it was pulled out and repositioned on the superior aspect of the liver; the urinary bladder was repaired. Patient did well postoperatively. This complication was revealed 1.5 years after the shunt was implanted. Although there were symptoms of dysuria and dribbling of urine of short duration, the patient did not show obvious peritoneal signs; suggesting that, penetration of a VP shunt into the urinary bladder can remain asymptomatic for a long period of time, disclosed late and can lead to considerable morbidity. Careful follow-up is important and management should be individualized 10).

2009

An unusual case of perforation of the distal end of the VP shunt into the bladder, with vesical calculus formation 11).

2002

A bladder stone formed secondary to the erosion of a ventriculoperitoneal shunt through a normal bladder wall 12).

1)

Blount JP, Campbell JA, Haines SJ. Complications in ventricular cerebrospinal fluid shunting. Neurosurg Clin N Am. 1993;4:633–56.
2)

Reddy GK, Bollam P, Shi R, Guthikonda B, Nanda A. Management of adult hydrocephalus with ventriculoperitoneal shunts: long-term single-institution experience. Neurosurgery. 2011;69(4):774–781.
3)

Villavicencio AT, Leveque JC, McGirt MJ, Hopkins JS, Fuchs HE, George TM. Comparison of revision rates following endoscopically versus nonendoscopically placed ventricular shunt catheters. Surg Neurol. 2003 May;59(5):375-9; discussion 379-80. PubMed PMID: 12765808.
4)

Park DB, Hill JG, Thacker PG, Rumboldt Z, Huda W, Ashley B, Hulsey T, Russell WS. The Role of Limited Head Computed Tomography in the Evaluation of Pediatric Ventriculoperitoneal Shunt Malfunction. Pediatr Emerg Care. 2016 Jun 14. [Epub ahead of print] PubMed PMID: 27299297.
5)

Afat S, Pjontek R, Hamou HA, Herz K, Nikoubashman O, Bamberg F, Brockmann MA, Nikolaou K, Clusmann H, Wiesmann M, Othman AE. Imaging of Ventriculoperitoneal Shunt Complications: Comparison of Whole Body Low-Dose Computed Tomography and Radiographic Shunt Series. J Comput Assist Tomogr. 2016 Aug 16. [Epub ahead of print] PubMed PMID: 27529684.
6)

Li XY, Wang ZC, Li YP, Ma ZY, Yang J, Cao EC. [Study on treatment strategy for ventriculitis associated with ventriculoperitoneal shunt for hydrocephalus]. Zhongguo Wei Zhong Bing Ji Jiu Yi Xue. 2005 Sep;17(9):558-60. Chinese. PubMed PMID: 16146606.
7)

Kurin M, Lee K, Gardner P, Fajt M, Umapathy C, Fasanella K. Clinical peritonitis from allergy to silicone ventriculoperitoneal shunt. Clin J Gastroenterol. 2017 Mar 6. doi: 10.1007/s12328-017-0729-0. [Epub ahead of print] PubMed PMID: 28265895.
8)

Chen BH, Drucker MD, Louis KM, Richards DW. Progression of Normal-Tension Glaucoma After Ventriculoperitoneal Shunt to Decrease Cerebrospinal Fluid Pressure. J Glaucoma. 2014 Oct 27. [Epub ahead of print] PubMed PMID: 25350819.
9)

Merkler AE, Ch’ang J, Parker WE, Murthy SB, Kamel H. The Rate of Complications after Ventriculoperitoneal Shunt Surgery. World Neurosurg. 2016 Nov 5. pii: S1878-8750(16)31137-8. doi: 10.1016/j.wneu.2016.10.136. [Epub ahead of print] PubMed PMID: 27826086.
10)

Gupta R, Dagla R, Agrawal LD, Sharma P. Vesical calculi formation on the slit valves of a migrated distal end of ventriculoperitoneal shunt. J Pediatr Neurosci. 2015 Oct-Dec;10(4):368-70. doi: 10.4103/1817-1745.174444. PubMed PMID: 26962346.
11)

Ramana Murthy KV, Jayaram Reddy S, Prasad DV. Perforation of the distal end of the ventriculoperitoneal shunt into the bladder with calculus formation. Pediatr Neurosurg. 2009;45(1):53-5. doi: 10.1159/000204904. Epub 2009 Mar 4. PubMed PMID: 19258730.
12)

Eichel L, Allende R, Mevorach RA, Hulbert WC, Rabinowitz R. Bladder calculus formation and urinary retention secondary to perforation of a normal bladder by a ventriculoperitoneal shunt. Urology. 2002 Aug;60(2):344. PubMed PMID: 12137842.

Korle-Bu Neuroscience Foundation

Korle-Bu Neuroscience Foundation

https://kbnf.org/

Korle-Bu Neuroscience Foundation (KBNF) is a Canada based charity enhancing the delivery of quality brain and spinal medical care in West Africa and beyond. The vision is to alleviate the suffering of West Africans with a special focus on those affected by diseases of the brain and spine, and to address related health care issues.

KBNF has been working with the Liberian Government since 2014 to develop its neurosurgery capacity, but the program is still in its infancy suffering setbacks from Ebola, lack of trained medical professionals across all disciplines, and extremely limited resources. KBNF works to address these deficits with shipments of equipment and supplies and annual medical missions.

Liberia recently employed the first neurosurgeon in the country‘s history. In a country with a population of 4.7 million people and staggering rates of cranial and spine trauma, as well as hydrocephalus and neural tube defects, neurosurgery is considered a luxury. A study documents the experience of a team of neurosurgeons, critical care nurses, scrub technicians, nurses, and Biomedical engineering who carried out a series of neurosurgical clinics and complex brain and spine surgeries in Liberia. Specifically, Bowen et al. aimed to highlight some of the larger obstacles, beyond staff and equipment, facing the development of a neurosurgical or any other specialty practice in Liberia.

The institutions, in collaboration with the Korle-Bu Neuroscience Foundation, spent 10 days in Liberia, based in Tappita, and performed 18 surgeries in addition to seeing several hundred clinic patients. This is a retrospective review of the cases performed along with outcomes to investigate obstacles in providing neurosurgical services in the country.

Before arriving in Liberia, they evaluated, planned, and supplied staff and materials for treating complex neurosurgical patients. Sixteen patients underwent 18 surgeries at a hospital in Tappita, Liberia, in November 2018. Their ages ranged from 1 month to 72 years (average 20 years). Five patients (28%) were female. Ten patients (56%) were under the age of 18. Surgeries included ventriculoperitoneal shunting (VP-shunt), lumbar myelomeningocele repair, encephalocele repair, laminectomy, and a craniotomy for tumor resection. Ten patients (55%) underwent VP-shunting. Two patients (11%) had a craniotomy for tumor resection. Three patients (17%) had laminectomy for lumbar stenosis. Two patients (11%) had repair of lumbar myelomeningocele.

After an aggressive and in-depth approach to planning, conducting, and supplying complex neurosurgical procedures in Liberia, the greatest limiting factor to successful outcomes lie in real-time is access to health care, which is largely limited by overall infrastructure. The study documents the experience of a team of neurosurgeons, critical care nurses, scrub technicians, nurses, and biomedical engineers who carried out a series of neurosurgical clinics and complex brain and spine surgeries in Liberia. Specifically, they aimed to highlight some of the larger obstacles, beyond staff and equipment, facing the development of a neurosurgical or any other specialty procedural practice in the country of Liberia. Most notably, they focused on infrastructure factors, including power, roads, water, education, and overall health care 1).

1)

Bowen I, Toor H, Zampella B, Doe A, King C, Miulli DE. Infrastructural Limitations in Establishing Neurosurgical Specialty Services in Liberia. Cureus. 2022 Sep 20;14(9):e29373. doi: 10.7759/cureus.29373. PMID: 36284802; PMCID: PMC9584543.

Cranioplasty for hydrocephalus prevention after decompressive craniectomy

Cranioplasty for hydrocephalus prevention after decompressive craniectomy

After decompressive craniectomy, the occurrence of hydrocephalus is reported with varying incidences (10–45%) mainly due to differences in diagnostic criteria 1) 2) 3) 4).

The management of Hydrocephalus after decompressive craniectomy in need of cranial reconstruction can be challenging and thus is not precisely defined. The debate mainly revolves around the timing of cerebrospinal fluid shunt with respect to the cranioplasty 5).

To prevent decompressive craniectomy complications, such as sinking skin flap syndrome, studies suggested early cranioplasty (CP). However, several groups reported higher complication rates in early CP. In a single-center observational cohort, study cranioplasty has high complication rates, 23%. Contrary to recent systematic reviews, early CP was associated with more complications (41%), explained by the higher incidence of pre-CP CSF flow disturbance and acute subdural hematoma as etiology of DC. CP in such patients should therefore be performed with the highest caution. 6).

Delayed time to cranioplasty is linked with the development of persistent hydrocephalus, necessitating permanent CSF diversion in some patients. Waziri et al., propose that early cranioplasty, when possible, may restore normal intracranial pressure dynamics and prevent the need for permanent CSF diversion 7).

Ozoner et al. showed that early cranioplasty within 2 months after decompressive craniectomy was associated with a lower rate of posttraumatic hydrocephalus 8)

The goal of the study of Sethi et al. was to ascertain the efficacy, safety, and comparability of ultra-early cranioplasty (CP; defined here as <30 days from the original craniectomy) to conventional cranioplasty (defined here as >30 days from the original craniectomy). A retrospective review of CPs performed between January 2016 and July 2020 was performed. Craniectomies initially performed at other institutions were excluded. Seventy-seven CPs were included in the study. Ultra-early CP was defined as CP performed within 30 days of craniectomy whereas conventional CP occurred after 30 days. Post-operative wound infection rates, rate of return to the operating room (OR) with or without bone flap removal, operative length, and rate of post-CP hydrocephalus were compared between the two groups. Thirty-nine and 38 patients were included in the ultra-early and conventional CP groups, respectively. The average number of days to CP in the ultra-early group was 17.70 ± 7.75 days compared to 95.70 ± 65.60 days in the conventional group. The mean Glasgow Coma Scale upon arrival to the emergency room was 7.28 ± 3.90 and 6.92 ± 4.14 for the ultra-early and conventional groups, respectively. The operative time was shorter in the ultra-early cohort than that in the conventional cohort (ultra-early, 2.40 ± 0.71 h; conventional, 3.00 ± 1.63 h; p = 0.0336). The incidence of post-CP hydrocephalus was also lower in the ultra-early cohort (ultra-early, 10.3%; conventional, 31.6%; p = 0.026). No statistically significant differences were observed regarding post-operative infection, return to the OR, or bone flap removal. The study shows that ultra-early CP can significantly reduce the rate of post-CP hydrocephalus, as well as operative time in comparison to conventional CP. However, the timing of CP post-DC should remain a patient-centered consideration 9).

1)

De Bonis P, Pompucci A, Mangiola A, Rigante L, Anile C. Post-traumatic hydrocephalus after decompressive craniectomy: an underestimated risk factor. J Neurotrauma. (2010) 27:1965–70. 10.1089/neu.2010.1425
2)

Cooper DJ, Rosenfeld JV, Murray L, Arabi YM, Davies AR, D’Urso P, et al.. Decompressive craniectomy in diffuse traumatic brain injury. N Engl J Med. (2011) 364:1493–502. 10.1056/NEJMoa1102077
3)

Honeybul S, Ho KM. Incidence and risk factors for post-traumatic hydrocephalus following decompressive craniectomy for intractable intracranial hypertension and evacuation of mass lesions. J Neurotrauma. (2012) 29:1872–8. 10.1089/neu.2012.2356
4)

Takeuchi S, Takasato Y, Masaoka H, Hayakawa T, Yatsushige H, Nagatani K, et al.. Hydrocephalus following decompressive craniectomy for ischemic stroke. Acta Neurochir Suppl. (2013) 118:289–91. 10.1007/978-3-7091-1434-6_56
5)

Iaccarino C, Kolias AG, Roumy LG, Fountas K, Adeleye AO. Cranioplasty Following Decompressive Craniectomy. Front Neurol. 2020 Jan 29;10:1357. doi: 10.3389/fneur.2019.01357. PMID: 32063880; PMCID: PMC7000464.
6)

Goedemans T, Verbaan D, van der Veer O, Bot M, Post R, Hoogmoed J, Lequin MB, Buis DR, Vandertop WP, Coert BA, van den Munckhof P. Complications in cranioplasty after decompressive craniectomy: timing of the intervention. J Neurol. 2020 May;267(5):1312-1320. doi: 10.1007/s00415-020-09695-6. Epub 2020 Jan 17. PMID: 31953606; PMCID: PMC7184041.
7)

Waziri A, Fusco D, Mayer SA, McKhann GM 2nd, Connolly ES Jr. Postoperative hydrocephalus in patients undergoing decompressive hemicraniectomy for ischemic or hemorrhagic stroke. Neurosurgery. 2007 Sep;61(3):489-93; discussion 493-4. PubMed PMID: 17881960.
8)

Ozoner B, Kilic M, Aydin L, Aydin S, Arslan YK, Musluman AM, Yilmaz A. Early cranioplasty associated with a lower rate of post-traumatic hydrocephalus after decompressive craniectomy for traumatic brain injury. Eur J Trauma Emerg Surg. 2020 Aug;46(4):919-926. doi: 10.1007/s00068-020-01409-x. Epub 2020 Jun 3. PMID: 32494837.
9)

Sethi A, Chee K, Kaakani A, Beauchamp K, Kang J. Ultra-Early Cranioplasty versus Conventional Cranioplasty: A Retrospective Cohort Study at an Academic Level 1 Trauma Center. Neurotrauma Rep. 2022 Aug 1;3(1):286-291. doi: 10.1089/neur.2022.0026. PMID: 36060455; PMCID: PMC9438438.

Setting sun sign

Setting sun sign

The setting sun sign (also known as the sunset eye sign or setting sun phenomenon) is a clinical phenomenon encountered in infants and young children with raised intracranial pressure.

It is an earlier sign of hydrocephalus than enlarged head circumference, full fontanelle, separation of sutures, irritability, vomiting. Consequently, this sign is a valuable early warning of an entity requiring prompt neuroimaging and urgent surgical intervention 1).

Part of Parinaud’s syndrome.

Definition

The “setting sun” sign is an ophthalmologic phenomenon where the eyes appear driven downward bilaterally. The inferior border of the pupil is often covered by the lower eyelid, creating the “sunset” appearance. This finding is classically associated with hydrocephalus in infants and children.

Epidemiology

Seen in up to 40% of children with obstructive hydrocephalus and 13% of children with shunt dysfunction 2).

In 126 children with internal hydrocephalus setting sun was descibed in 51, syndrome of the aqueduct of Sylvius 14, paresis of craniocerebral nerves 9, nystagmus 8, optic atrophy 4 3).

Clinical features

It consists of an up-gaze paresis with the eyes appearing driven downward. The lower portion of the pupil may be covered by the lower eyelid, and sclera may be seen between the upper eyelid and the iris.

Pathogenesis

The pathogenesis of the setting sun sign is believed to be related to aqueductal distention in the dorsal midbrain on the vertical gaze innervation bilaterally. In children with hydrocephalus, up to 40% of cases will present with this sign. Of these patients, 13% harbor ventriculoperitoneal shunts that have failed. The sign is also associated with kernicterus and other features of the full Parinaud syndrome (i.e., dorsal midbrain syndrome). Interestingly, the setting sun sign may also transiently appear in healthy infants up to 7 months of age 4).

Chattha et al. suggest periaqueductal dysfunction rather than mechanical displacement as the possible mechanism for this sign 5).

Outcome

In hydrocephalus, the convulsion and so-called setting sun sign had no significant correlation to poor prognosis 6).

Despite the fact that setting sun eye is a grave sign, most commonly accompanied by other neurological signs and symptoms suggesting serious diseases, it might be observed as a sole finding in a totally normal infant with inconclusive brain imaging and laboratory tests 7).

Case series

A cross-sectional study was conducted in the Children’s Hospital Medical Center in Tehran from June 2001 to 2006. The study included 15 healthy infants who were referred to the neurosurgery clinic for setting sun eye. All were evaluated with brain imaging, and laboratory tests including at least thyroid function tests, and serum calcium and phosphorus. The cases were followed by regular outpatient visits until the age of 2 years.

They were 3-8 months old at the time of referring to the outpatient clinic. Setting sun eye was observed by the mother in all cases and confirmed during their visit to the clinic. All had normal brain imaging and normal laboratory tests (thyroid function and electrolytes). Setting sun eye disappeared gradually during the follow-up period with a range of 2-8 months after detection by the mother.

Despite the fact that setting sun eye is a grave sign, most commonly accompanied by other neurological signs and symptoms suggesting serious diseases, it might be observed as a sole finding in a totally normal infant with inconclusive brain imaging and laboratory tests. We found that this type of setting sun eye has a benign course and will disappear without any intervention several months after its detection (commonly before the age of 2 years without any intervention) 8).

19 infants who displayed the setting-sun eye phenomenon were observed during the first year of life. Nine of the infants showed no signs of illness, eight had an evident increase in intracranial pressure requiring surgical relief, and two had transient signs of increased intracranial pressure which resolved spontaneously. The setting-sun phenomenon could be elicited both by alteration of the infant’s position and by removal of light, and it also occurred spontaneously. The effectiveness of the eliciting mechanism depended on the age of the infant. The component parts of the phenomenon consist of downward rotation of the eyeballs and retraction of the upper eyelids, sometimes accompanied by raising of the brow. The phenomenon can be observed in healthy infants, and its value in early recognition of increased intracranial pressure is limited. The response might indicate increased intracranial pressure if it can be elicited by alteration of position in infants older than four weeks of age or if there is a marked response to removal of light in infants younger than eight weeks or older than 20 weeks of age, especially if the response is combined with constant or intermittent strabismus or undulating eye-movements 9).

Eight cases of obstructive hydrocephalus manifesting palsy of upward gaze and other features of the Sylvian aqueduct syndrome are reported. During the crisis of intracranial hypertension, all of them developed upward gaze palsy and variable abnormalities of the convergence mechanism such as paralysis, spasm, and convergence nystagmus. The frequent apparent blindness was probably related to gaze paralysis since visual evoked responses were present. All these ocular abnormalities disappeared after shunting. Periaqueductal dysfunction on the basis of raised intracranial pressure is postulated as the possible mechanism for the above ocular manifestations. The ‘setting sun’ sign is frequently seen in infants and children with hydrocephalus and has been considered in the past to result from the displacement of eyeballs by pressure from the orbital roof plate. Our observations would suggest periaqueductal dysfunction rather than the mechanical displacement as the possible mechanism for this sign 10).

Case reports

Yoshikawa reported two normally developed infants showing benign“ setting sun” phenomenon. A 2(2-12)-year-old boy and a 7-year-old boy, who were born without any complications at full term, developed brief episodes of downward gazing during sucking and crying after birth However, there were no other clinical or laboratory findings, and they developed normally. The phenomenon was not visible until 6 months and 7 months, respectively. The “setting sun” phenomenon usually indicates underlying severe brain damage and can also be seen, although rarely, in healthy full-term infants until 1 to 5 months. However, the benign “setting sun” phenomenon might exist until 6 or 7 months of age in normal infants 11).

References

1) , 2)

Boragina M, Cohen E. An infant with the “setting-sun” eye phenomenon. CMAJ. 2006 Oct 10;175(8):878. PubMed PMID: 17030938; PubMed Central PMCID: PMC1586074.
3)

Tzekov C, Cherninkova S, Gudeva T. Neuroophthalmological symptoms in children treated for internal hydrocephalus. Pediatr Neurosurg. 1991-1992;17(6):317-20. PubMed PMID: 1840820.
4)

Croft, D.E., Almarzouqi, S.J., Morgan, M.L., Lee, A.G. (2018). Setting Sun Sign. In: Schmidt-Erfurth, U., Kohnen, T. (eds) Encyclopedia of Ophthalmology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-69000-9_1226
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Chattha AS, Delong GR. Sylvian aqueduct syndrome as a sign of acute obstructive hydrocephalus in children. J Neurol Neurosurg Psychiatry. 1975 Mar;38(3):288-96. PubMed PMID: 1151409; PubMed Central PMCID: PMC491910.
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Ito H, Onodera Y, Takanashi K, Tajima K, Miwa T. [Some observations on prognosis in congenital hydrocephalus (first report)–with reference to the preoperative evaluation of the hydrocephalic infants (author’s transl)]. No Shinkei Geka. 1975 Mar;3(3):245-54. Japanese. PubMed PMID: 1238932.
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Nejat F, Yazdani S, El Khashab M. Setting sun eye in normal healthy infants. Pediatr Neurosurg. 2008;44(3):190-2. doi: 10.1159/000120148. Epub 2008 Mar 11. PubMed PMID: 18334841.
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Cernerud L. The setting-sun eye phenomenon in infancy. Dev Med Child Neurol. 1975 Aug;17(4):447-55. PubMed PMID: 1158051.
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Yoshikawa H. Benign “setting sun” phenomenon in full-term infants. J Child Neurol. 2003 Jun;18(6):424-5. PubMed PMID: 12886979

Idiopathic normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus

J.Sales-Llopis

Neurosurgery Department, University General Hospital of Alicante, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region (FISABIO), Alicante, Spain

Definition

Idiopathic Normal Pressure Hydrocephalus Definition.

History

see Idiopathic normal pressure hydrocephalus history.

Epidemiology

Idiopathic Normal Pressure Hydrocephalus Epidemiology.

Classification

Idiopathic Normal Pressure Hydrocephalus Classification.

Idiopathic Normal Pressure Hydrocephalus Natural History

Idiopathic Normal Pressure Hydrocephalus Natural History

Etiology

Idiopathic Normal Pressure Hydrocephalus Etiology.

Pathogenesis

see Idiopathic normal pressure hydrocephalus Pathogenesis.

Pathophysiology

see Idiopathic normal pressure hydrocephalus pathophysiology.

Clinical Features

see Idiopathic normal pressure hydrocephalus clinical features.

Scales

see Idiopathic normal pressure hydrocephalus scales

Diagnosis

see Idiopathic normal pressure hydrocephalus diagnosis

Differential diagnosis

see Idiopathic normal pressure hydrocephalus differential diagnosis.

Guidelines

Idiopathic normal pressure hydrocephalus guidelines

Treatment

see Idiopathic normal pressure hydrocephalus treatment.

Outcome

see Idiopathic normal pressure hydrocephalus outcome.

Case series

see Idiopathic normal pressure hydrocephalus case series.

Case reports

see Idiopathic normal pressure hydrocephalus case reports.

Experimental animal model

see Idiopathic normal pressure hydrocephalus experimental animal model.

Choroid plexus hyperplasia

Choroid plexus hyperplasia

Choroid plexus hyperplasia (CPH), also known as villous hypertrophy of the choroid plexus, is a rare benign condition that is characterized by bilateral enlargement of the entire choroid plexus in lateral ventricles without any discrete masses. This can result in overproduction of CSF and communicating hydrocephalus.

Pathophysiology

Despite the current knowledge about hydrocephalus, we remain without a complete understanding of the pathophysiology of this condition. glymphatic system (GS) could be more important than the conventional concept of reabsorption of CSF in the arachnoid villi, therefore GS could be a new key point, which will guide future investigations 1).

Pathology

Histology shows an increased number of normal-sized cells.

Radiographic features

MRI

This is best diagnosed by MRI which demonstrates a diffuse enlargement and homogeneous enhancement of choroid plexuses in a patient with communicating hydrocephalus 2).

Treatment

It is a rare condition that may necessitate unusual treatment paradigms.

Although some authors recommend choroid plexus excision or coagulation, ventriculoatrial shunt insertion is a simple and effective treatment modality in cases of diffuse villous hyperplasia of the choroid plexus 3).

It can be seen in trisomy 9p where coexisting congenital heart disease additionally may complicate the therapeutic approach 4).

Case reports

At 20 months of age, a Caucasian girl with trisomy 9 and a family history of an older brother and twin sister having the same syndrome displayed signs of congenital hydrocephalus due to increasing head circumference. Magnetic resonance imaging revealed enlarged lateral ventricles and a prominent choroid plexus and the girl was treated with a ventriculoperitoneal shunt, which 2 days later had to be replaced with a ventriculoatrial shunt as cerebrospinal fluid production greatly exceeded the ability of the patient’s abdominal absorptive capability. At 16 years of age, the patient was diagnosed with cardiomyopathy and diminished ejection fraction. Some months later, she was admitted to the neurosurgical ward showing signs of shunt dysfunction due to a colloid cyst in the third ventricle. Cystic drainage through endoscopic puncture only helped temporarily. Revision of the shunt system showed occlusion of the ventricular drainage, and replacement was merely temporary alleviating. Intracranial pressure was significantly increased at around 30 mmHg, prompting externalization of the drain, and measurements revealed high cerebrospinal fluid production of 60-100 ml liquor per hour. Thus, endoscopic choroid plexus coagulation was performed bilaterally leading to an immediate decrease of daily cerebrospinal fluid formation to 20-30 ml liquor per hour, and these values were stabilized by pharmaceutical treatment with acetazolamide 100 mg/kg/day and furosemide 1 mg/kg/day. Subsequently, a ventriculoperitoneal shunt was placed. Follow-up after 1 and 2 months displayed no signs of hydrocephalus or ascites.

High cerebrospinal fluid volume load and coexisting heart disease in children with trisomy 9p may call for endoscopic choroid plexus coagulation and pharmacological therapy to diminish the daily cerebrospinal fluid production to volumes that allow proper ventriculoperitoneal shunting 5).

A 1-year-old patient was diagnosed with communicating hydrocephalus; ventricle peritoneal shunt (VPS) is installed and ascites developed. VPS is exposed, yielding volumes of 1000-1200ml/day CSF per day. MRI is performed showing generalized choroidal plexus hyperplasia. Bilateral endoscopic coagulation of thechoroid plexus was performed in 2 stages (CPC) however the high rate of CSF production persisted, needing a bilateral plexectomy through septostomy, which finally decreased the CSF outflow.

New knowledge about CSF physiology will help to propose better treatment depending on the cause of the hydrocephalus. The GS is becoming an additional reason to better study and develop new therapies focused on the modulation of alternative CSF reabsorption. 6).

In these patients, intractable ascites can occur after a ventriculoperitoneal (VP) shunting operation. However, shunt-related hydrocele is a rare complication of VP shunting. Previous reports have indicated catheter-tip migration to the scrotum as a cause of hydrocele. Here, we present the first documented case of choroid plexus hyperplasia that led to intractable ascites after shunting and a resulting hydrocele without catheter-tip migration into the scrotum 7).

1) , 6)

Paez-Nova M, Andaur K, Campos G, Garcia-Ballestas E, Moscote-Salazar LR, Koller O, Valenzuela S. Bilateral hyperplasia of choroid plexus with severe CSF production: a case report and review of the glymphatic system. Childs Nerv Syst. 2021 Nov;37(11):3521-3529. doi: 10.1007/s00381-021-05325-2. Epub 2021 Aug 19. PMID: 34410450.
2)

https://radiopaedia.org/articles/choroid-plexus-hyperplasia
3)

Iplikcioglu AC, Bek S, Gökduman CA, Bikmaz K, Cosar M. Diffuse villous hyperplasia of choroid plexus. Acta Neurochir (Wien). 2006 Jun;148(6):691-4; discussion 694. doi: 10.1007/s00701-006-0753-1. Epub 2006 Mar 8. PMID: 16523225.
4) , 5)

Henningsen MB, Gulisano HA, Bjarkam CR. Congenital hydrocephalus in a trisomy 9p gained child: a case report. J Med Case Rep. 2022 May 27;16(1):206. doi: 10.1186/s13256-022-03424-5. PMID: 35619116.
7)

Hori YS, Nagakita K, Ebisudani Y, Aoi M, Shinno Y, Fukuhara T. Choroid Plexus Hyperplasia with Intractable Ascites and a Resulting Communicating Hydrocele following Shunt Operation for Hydrocephalus. Pediatr Neurosurg. 2018;53(6):407-412. doi: 10.1159/000492333. Epub 2018 Aug 29. PMID: 30157489.

Shunt for Idiopathic normal pressure hydrocephalus treatment

Shunt for Idiopathic normal pressure hydrocephalus treatment

Indications

• Early shunt surgery can significantly improve the clinical symptoms and prognosis of patients with idiopathic normal pressure hydrocephalus (iNPH). • Structural imaging findings have limited predictiveness for the prognosis of patients with iNPH after shunt surgery. • Patients should not be selected for shunt surgery based on only structural imaging findings 1).

Clinical decisions regarding Shunt for Idiopathic normal pressure hydrocephalus treatment should be individualized to each patient, with adequate consideration of the relative risks and benefits, including maximizing a healthy life expectancy 2).

Ventriculoperitoneal shunt for idiopathic normal pressure hydrocephalus

see Ventriculoperitoneal shunt for idiopathic normal pressure hydrocephalus.

Lumboperitoneal shunt for idiopathic normal pressure hydrocephalus

see Lumboperitoneal shunt for idiopathic normal pressure hydrocephalus.

1)

Chen J, He W, Zhang X, Lv M, Zhou X, Yang X, Wei H, Ma H, Li H, Xia J. Value of MRI-based semi-quantitative structural neuroimaging in predicting the prognosis of patients with idiopathic normal pressure hydrocephalus after shunt surgery. Eur Radiol. 2022 Apr 30. doi: 10.1007/s00330-022-08733-3. Epub ahead of print. PMID: 35501572.
2)

Nakajima M, Kuriyama N, Miyajima M, Ogino I, Akiba C, Kawamura K, Kurosawa M, Watanabe Y, Fukushima W, Mori E, Kato T, Sugano H, Tange Y, Karagiozov K, Arai H. Background Risk Factors Associated with Shunt Intervention for Possible Idiopathic Normal Pressure Hydrocephalus: A Nationwide Hospital-Based Survey in Japan. J Alzheimers Dis. 2019 Mar 11. doi: 10.3233/JAD-180955. [Epub ahead of print] PubMed PMID: 30883349.

Ventriculostomy related infection risk factors

Ventriculostomy related infection risk factors

Ventriculostomy related infection risk factors include prior brain surgery, cerebrospinal fluid fistula, and insertion site dehiscence. Walek et al. from Rhode Island Hospital found no significant association between infection risk and duration of external ventricular drainage placement 1).

A total of 15 supposed influencing factors includes: age, age & sex interactions, coinfection, catheter insertion outside the hospital, catheter type, CSF leakage, CSF sampling frequency, diagnosis, duration of catheterization, ICP > 20 mmHg, irrigation, multiple catheter, neurosurgical operation, reduced CSF glucose at catheter insertion and sex 2).

In a large series of patients, ventriculostomy related infection (VRI) was associated with a longer ICU stay, but its presence did not influence survival. A longer duration of ventriculostomy catheter monitoring in patients with VRI might be due to an increased volume of drained CSF during infection. Risk factors associated with VRIs are SAH, IVH, craniotomy, and coinfection 3).

A retrospective cohort study strengthens a growing body of works suggesting the importance of inoculation of skin flora as a critical risk factor in ventriculostomy related infections, underscoring the importance of drain changes only when clinically indicated and, that as soon as clinically permitted, catheters should be removed 4).

Associated with a longer ICU stay, but its presence did not influence survival. A longer duration of ventriculostomy catheter monitoring in patients with VAI might be due to an increased volume of drained CSF during infection. Risk factors associated with VAIs are subarachnoid hemorrhage (SAH), intraventricular hemorrhage IVH, craniotomy, and coinfection 5).

The risk of infection increases with increasing duration of catheterization and with repeated insertions. The use of local antibiotic irrigation or systemic antibiotics does not appear to reduce the risk of VAI. Routine surveillance cultures of CSF were no more likely to detect infection than cultures obtained when clinically indicated. These findings need to be considered in infection control policies addressing this important issue 6).

An increased risk of infection has been observed in patients with subarachnoid or intraventricular hemorrhage, in patients with concurrent systemic infections as well as with longer duration of catheterization, cerebrospinal (CSF) leakage, and frequent manipulation of the EVD system 7) 8) 9).

Many studies have been conducted to identify risk factors of EVD-related infections. However, none of these risk factors could be confirmed in a cohort of patients. Furthermore they not show any difference in infection rates between patients who were placed in single- or multibed rooms, respectively 10).

Interestingly no risk factor for EVD-related infection could be identified in a retrospective single center study 11).

References

1)

Walek KW, Leary OP, Sastry R, Asaad WF, Walsh JM, Horoho J, Mermel LA. Risk factors and outcomes associated with external ventricular drain infections. Infect Control Hosp Epidemiol. 2022 Apr 26:1-8. doi: 10.1017/ice.2022.23. Epub ahead of print. PMID: 35471129.
2)

Sorinola A, Buki A, Sandor J, Czeiter E. Risk Factors of External Ventricular Drain Infection: Proposing a Model for Future Studies. Front Neurol. 2019 Mar 15;10:226. doi: 10.3389/fneur.2019.00226. eCollection 2019. Review. PubMed PMID: 30930840; PubMed Central PMCID: PMC6428739.
3)

Bota DP, Lefranc F, Vilallobos HR, Brimioulle S, Vincent JL. Ventriculostomy-related infections in critically ill patients: a 6-year experience. J Neurosurg. 2005 Sep;103(3):468-72. PubMed PMID: 16235679.
4)

Katzir M, Lefkowitz JJ, Ben-Reuven D, Fuchs SJ, Hussein K, Sviri G. Decreasing external ventricular drain related infection rates with duration-independent, clinically indicated criteria for drain revision: A retrospective study. World Neurosurg. 2019 Aug 2. pii: S1878-8750(19)32121-7. doi: 10.1016/j.wneu.2019.07.205. [Epub ahead of print] PubMed PMID: 31382072.
5)

Bota DP, Lefranc F, Vilallobos HR, Brimioulle S, Vincent JL. Ventriculostomy-related infections in critically ill patients: a 6-year experience. J Neurosurg. 2005 Sep;103(3):468-72. PubMed PMID: 16235679.
6)

Arabi Y, Memish ZA, Balkhy HH, Francis C, Ferayan A, Al Shimemeri A, Almuneef MA. Ventriculostomy-associated infections: incidence and risk factors. Am J Infect Control. 2005 Apr;33(3):137-43. PubMed PMID: 15798667.
7)

Camacho E. F., Boszczowski Í., Basso M., Jeng B. C. P., Freire M. P., Guimarães T., Teixeira M. J., Costa S. F. Infection rate and risk factors associated with infections related to external ventricular drain. Infection. 2011;39(1):47–51. doi: 10.1007/s15010-010-0073-5.
8)

Kim J.-H., Desai N. S., Ricci J., Stieg P. E., Rosengart A. J., Hrtl R., Fraser J. F. Factors contributing to ventriculostomy infection. World Neurosurgery. 2012;77(1):135–140. doi: 10.1016/j.wneu.2011.04.017.
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Mayhall C. G., Archer N. H., Lamb V. A., Spadora A. C., Baggett J. W., Ward J. D., Narayan R. K. Ventriculostomy-related infections. A positive epidemiologic study. The New England Journal of Medicine. 1984;310(9):553–559. doi: 10.1056/NEJM198403013100903.
10)

Hagel S, Bruns T, Pletz MW, Engel C, Kalff R, Ewald C. External Ventricular Drain Infections: Risk Factors and Outcome. Interdiscip Perspect Infect Dis. 2014;2014:708531. Epub 2014 Nov 17. PubMed PMID: 25484896; PubMed Central PMCID: PMC4251652.
11)

Hagel S, Bruns T, Pletz MW, Engel C, Kalff R, Ewald C. External ventricular drain infections: risk factors and outcome. Interdiscip Perspect Infect Dis. 2014;2014:708531. doi: 10.1155/2014/708531. Epub 2014 Nov 17. PubMed PMID: 25484896; PubMed Central PMCID: PMC4251652.

Obstructive hydrocephalus from posterior fossa tumor risk factors

Obstructive hydrocephalus from posterior fossa tumor risk factors

Saad et al. from the Emory University Hospital surveyed the CNS (Central Nervous System) Tumor Outcomes Registry at Emory (CTORE) for patients who underwent posterior fossa tumor surgery at 3 tertiary-care centers between 2006 and 2019. Demographic, radiographic, perioperative, and dispositional data were analyzed using univariate and multivariate models.

They included 617 patients undergoing PFT resection for intra-axial (57%) or extra-axial (43%) lesions. Gross total resection was achieved in 62% of resections. Approximately 13% of patients required permanent cerebrospinal fluid shunt. Only 31.5% of patients who required pre- or intraop external ventricular drain (EVD) placement needed permanent cerebrospinal fluid shunt. On logistic regression, Tumor size, transependymal edema, use of perioperative external ventricular drain, postoperative intraventricular hemorrhage (IVH), and surgical complications were predictors of permanent CSF diversion. Preoperative tumor size was the only independent predictor of postoperative shunting in patients with subtotal resection. In patients with intra-axial tumors, transependymal flow (P = .014), postoperative IVH (P = .001), surgical complications (P = .013), and extent of resection (P = .03) predicted need for shunting. In extra-axial tumors, surgical complications were the major predictor (P = .022).

The study demonstrates that the presence of preoperative hydrocephalus in patients with PFT does not necessarily entail the need for permanent CSF diversion. Saad et al. reported the major predictive factors for needing a permanent cerebrospinal fluid shunt for obstructive hydrocephalus 1).

Superior tumor extension (into the aqueduct) and failed total resection of tumor were identified as independent risk factors for postoperative hydrocephalus in patients with fourth ventricle tumor 2).

Cully and colleagues analyzed 117 patients and found the following factors to be associated with a higher incidence of postresection hydrocephalus (PRH): age <3 years, midline tumor location, subtotal resection, prolonged EVD requirement, cadaveric dural grafts, pseudomeningocele formation, and CSF infections 3).

Due-Tonnessen and Hleseth found that patients with medulloblastoma and ependymoma had much higher rates of postoperative shunt placement than astrocytomas 4). Kumar and colleagues in a study of 196 consecutive children found age <3 years, tumor histology of medulloblastoma/ependymoma and partial resections were associated with the increased chances of postresection hydrocephalus 5). A study noted that the only modifiable risk factor for the development of PRH was the presence of intraventricular blood in postoperative imaging 6).

Intraventricular blood can cause hydrocephalus either by the “snow globe effect” 7) or by other factors like impaired absorption of CSF by inflammation and fibrosis of the arachnoid granulations caused by blood degradation products 8).

Gopalakrishnan and colleagues noted the following risk factors for PRH: the need for CSF diversion in the pediatric population—children with symptomatology <3 months duration, severe hydrocephalus at presentation, tumor location in the midline, tumor histology, viz. medulloblastoma and ependymoma, use of intraoperative EVD, longer duration of EVD, postoperative meningitis, and pseudomeningocele 9). Similar findings were also reported by Bognar et al. who showed that the presence of EVD and the duration of EVD were associated with a significant increase in the incidence of postresection CSF diversion. In another recent study, Pitsika et al. 10) showed that patients who underwent EVD had a higher rate of postoperative VPS. They also noted a negative correlation between early EVD clamping and VPS indicating that clamping encourages the re-establishment of normal CSF flow when the obstructive tumor is removed 11). From 12).

Choroid plexus cysts (CPCs) are a type of neuroepithelial cysts, benign lesions located more frequently in the supratentorial compartment. Symptomatic CPCs in the posterior fossa are extremely rare and can be associated with obstructive hydrocephalus

Systematic Review

Predictive factors for postoperative hydrocephalus has been identified, including young age (< 3 years), severe symptomatic hydrocephalus at presentation, EVD placement before surgery, FOHR index > 0.46 and Evans index > 0.4, pseudomeningocele, cerebrospinal fluid fistula, and infection. The use of a pre-resection cerebrospinal fluid shunt in case of signs and symptoms of hydrocephalus is mandatory, although it resolves in the majority of cases. As reported by several studies included in the present review, we suggest CSF shunt also in case of asymptomatic hydrocephalus, whereas it is not indicated without evidence of ventricular dilatation 13).

1)

Saad H, Bray DP, McMahon JT, Philbrick BD, Dawoud RA, Douglas JM, Adeagbo S, Yarmoska SK, Agam M, Chow J, Pradilla G, Olson JJ, Alawieh A, Hoang K. Permanent cerebrospinal fluid shunt in Adults With Posterior Fossa Tumors: Incidence and Predictors. Neurosurgery. 2021 Nov 18;89(6):987-996. doi: 10.1093/neuros/nyab341. PMID: 34561703; PMCID: PMC8600168.
2)

Chen T, Ren Y, Wang C, Huang B, Lan Z, Liu W, Ju Y, Hui X, Zhang Y. Risk factors for hydrocephalus following fourth ventricle tumor surgery: A retrospective analysis of 121 patients. PLoS One. 2020 Nov 17;15(11):e0241853. doi: 10.1371/journal.pone.0241853. PMID: 33201889; PMCID: PMC7671531.
3)

Cully DJ, Berger MS, Shaw D, Geyer R. An analysis of factors determing the need for ventriculoperitoneal shunts after posterior fossa tumor surgery in children. Neurosurgery 1994;34:402-8.
4) , 8)

Due-Tonnessen B, Helseth E. Management of hydrocephalus in children with posterior fossa tumors: Role of tumor surgery. Pediatr Neurosurg 2007;43:92-6
5)

Kumar V, Phipps K, Harkness W, Hayward RD. Ventriculoperitoneal shunt requirement in children with posterior fossa tumors: An 11-year audit. Br J Neurosurg 1996:10:467-70.
6)

Abraham A, Moorthy RK, Jeyaseelan L, Rajshekhar V. Postoperative intraventricular blood: A new modifiable risk factor for early postoperative symptomatic hydrocephalus in children with posterior fossa tumors. Childs Nerv Syst 2019;35;1137-46.
7)

Tamburrini G, Frassanito P, Bianchi F, Massimi L, Di Rocco C, Caldarelli M. Closure of endoscopic third ventriculostomy after surgery for posterior cranial fossa tumor: The “Snow Globe effect”. Br J Neurosurg 2015;29:386-9.
9)

Gopalakrishnan CV, Dhakoji A, Menon G, Nair S. Factors predicting the need for cerebrospinal fluid diversion following posterior cranial fossa tumor surgery in children. Pediatr Neurosurg 2012;48:93-101
10)

Pitsika M, Fletcher J, Coulter IC, Cowie CJA. A validation study of the modified Canadian preoperative prediction rule for hydrocephalus in children with posterior fossa tumors. J Neurosurg. doi: 10.3171/2021.1.PEDS20887.
11)

Bognar L, Borgulya G, Benke P, Madarassy G. Analysis of CSF shunting procedure requirement in children with posterior fossa tumors. Childs Nerv Syst 2003;19:332-6.
12)

Muthukumar N. Hydrocephalus Associated with Posterior Fossa Tumors: How to Manage Effectively? Neurol India. 2021 Nov-Dec;69(Supplement):S342-S349. doi: 10.4103/0028-3886.332260. PMID: 35102986.
13)

Anania P, Battaglini D, Balestrino A, D’Andrea A, Prior A, Ceraudo M, Rossi DC, Zona G, Fiaschi P. The role of external ventricular drainage for the management of posterior cranial fossa tumours: a systematic review. Neurosurg Rev. 2021 Jun;44(3):1243-1253. doi: 10.1007/s10143-020-01325-z. Epub 2020 Jun 3. PMID: 32494987.