Hydrocephalus Classification

Hydrocephalus Classification

There is no international consensus on the classification of hydrocephalus, and there are various systems based on the age of onset, cerebrospinal fluid dynamics and anatomical area of accumulation, the levels of cerebrospinal fluid pressure and the presence of symptoms.

However, no definitive classification exists comprehensively to cover the variety of these aspects.

Wu et al. proposed a classification Based on Ventricular Pressure 1).


Walter Edward Dandy first described the basic mechanism and classification of hydrocephalus as:

Obstructive hydrocephalus or Non Obstructive hydrocephalus.

Despite advances in understanding of the underlying process, current classification systems still rely upon Dandy’s classification scheme 2).


The aim of a study was to evaluate the diagnostic utility of three-dimensional sampling perfection with application optimized contrast using different flip angle evolution (3D SPACE) sequence and Susceptibility Weighted Imaging (SWI) in hydrocephalus and to propose a refined definition and classification of hydrocephalus with relevance to the selection of treatment option.

A prospective study of 109 patients with hydrocephalus was performed with magnetic resonance imaging (MRI) brain using standardized institutional sequences along with additional sequences 3D SPACE and SWI. The images were independently read by two senior neuroradiologists and the etiopathogenesis of hydrocephalus was arrived by consensus.

With conventional sequences, 46 out of 109 patients of hydrocephalus were diagnosed as obstructive of which 21 patients showed direct signs of obstruction and 25 showed indirect signs. In the remaining 63 patients of communicating hydrocephalus, cause could not be found out in 41 patients. Whereas with 3D SPACE sequence, 88 patients were diagnosed as obstructive hydrocephalus in which all of them showed direct signs of obstruction and 21 patients were diagnosed as communicating hydrocephalus. By including SWI, we found out hemorrhage causing intraventricular obstruction in three patients and hemorrhage at various sites in 24 other patients. With these findings, we have classified the hydrocephalus into communicating and noncommunicating, with latter divided into intraventricular and extraventricular obstruction, which is very well pertaining to the selection of surgical option.

Chellathurai et al., strongly suggest to include 3D SPACE and SWI sequences in the set of routine MRI sequences, as they are powerful diagnostic tools and offer complementary information regarding the precise evaluation of the etiopathogenesis of hydrocephalus and have an effective impact in selecting the mode of management 3).

Terms used

Acquired hydrocephalus

Adult hydrocephalus

Arrested hydrocephalus or Compensated hydrocephalus

Chronic hydrocephalus

Communicating hydrocephalus or Non obstructive hydrocephalus

Congenital hydrocephalus

External hydrocephalus

Focal hydrocephalus

Hydrocephalus Ex Vacuo

Idiopathic normal pressure hydrocephalus

Infantile hydrocephalus or Pediatric hydrocephalus.

Internal hydrocephalus

Non obstructive hydrocephalus or Communicating hydrocephalus

Normal pressure hydrocephalus for Idiopathic normal pressure hydrocephalus or Secondary normal pressure hydrocephalus.

Obstructive hydrocephalus.

Pediatric hydrocephalus or Infantile hydrocephalus

Secondary normal pressure hydrocephalus.


With the rare exception of hydrocephalus associated with overproduction of CSF in patients with choroid plexus papillomas (CPPs), all hydrocephalus is basically obstructive hydrocephalus. That the rare CPP causes hydrocephalus is not debated, but why it does so is the subject of some discussion. CPPs are known to lead to increases in the rate of CSF production and are known to cause hydrocephalus.

Normal CSF absorptive mechanisms can clear the amount of spinal fluid produced in the ventricular system at extremely high rates without producing ventriculomegaly. If CSF production and ICP increase substantially, ventricular size increases 4). When CSF flow is obstructed in the context of increased CSF production, there is a great tendency for ventriculomegaly or hydrocephalus to develop. CPPs, in themselves, can create the only pure form of communicating hydrocephalus. However, that these tumors tend to be large and to restrict CSF flow through the foramen of Monro or aqueduct of Sylvius, is more likely to account for the severity of hydrocephalus in this context 5).

When hydrocephalus is severe, especially in the very young, it may not be possible to define the point of CSF obstruction without introducing tracers into the CSF pathways. In patients treated early in life whose ventricles have become smaller with treatment, it is possible to determine the first site of obstruction to CSF flow on MRI or CT.

Patients with complex congenital anomalies such as hydrocephalus related to a Chiari II malformation and spina bifida often have multiple sites of obstruction 6) 7). It may not be possible to predict a second or downstream point of obstruction. In these patients, only one point may be obstructed or all of these sites may be restricted.

Based on a analyses from a mathematical modeling, of the work on the circuitry of CSF flow, and these potential sites of obstruction, Rekate et al., proposed a classification

It is generally assumed that endoscopic third ventriculostomy (ETV) is only effective for treating obstructive hydrocephalus, and many assume that obstructive hydrocephalus is synonymous with aqueductal stenosis. The growing number of reports on the efficacy of ETV for treating “communicating hydrocephalus” has generated considerable consternation 8).


The “Multi-categorical Hydrocephalus Classification” (Mc HC), was invented and developed to cover the entire aspects of hydrocephalus with all considerable classification items and categories.

Ten categories include “Mc HC” category I: onset (age, phase), II: cause, III: underlying lesion, IV: symptomatology, V: pathophysiology 1-CSF circulation, VI: pathophysiology 2-ICP dynamics, VII: chronology, VII: post-shunt, VIII: post-endoscopic third ventriculostomy, and X: others. From a 100-year search of publication related to the classification of hydrocephalus, 14 representative publications were reviewed and divided into the 10 categories.

The Baumkuchen classification graph made from the round o’clock classification demonstrated the historical tendency of deviation to the categories in pathophysiology, either CSF or ICP dynamics.

In the preliminary clinical application, it was concluded that “Mc HC” is extremely effective in expressing the individual state with various categories in the past and present condition or among the compatible cases of hydrocephalus along with the possible chronological change in the future 9).

References

1)

Wu X, Zang D, Wu X, Sun Y, Yu J, Hu J. Diagnosis and Management for Secondary Low- or Negative-Pressure Hydrocephalus and a New Hydrocephalus Classification Based on Ventricular Pressure. World Neurosurg. 2019 Jan 4. pii: S1878-8750(18)32946-2. doi: 10.1016/j.wneu.2018.12.123. [Epub ahead of print] PubMed PMID: 30611954.
2)

Dandy WE, Blackfan KD. Internal hydrocephalus: an experimental, clinical and pathological study. Am J Dis Child. 1914;8(6):406-482.
3)

Chellathurai A, Subbiah K, Abdul Ajis BN, Balasubramaniam S, Gnanasigamani S. Role of 3D SPACE sequence and susceptibility weighted imaging in the evaluation of hydrocephalus and treatment-oriented refined classification of hydrocephalus. Indian J Radiol Imaging. 2018 Oct-Dec;28(4):385-394. doi: 10.4103/ijri.IJRI_161_18. PubMed PMID: 30662197; PubMed Central PMCID: PMC6319109.
4) , 5)

Rekate HL, Erwood S, Brodkey JA, Chizeck HJ, Spear T, Ko W, Montague F. Etiology of ventriculomegaly in choroid plexus papilloma. Pediatr Neurosci. 1985;12:196–201.
6)

Rekate HL. Neurosurgical management of the newborn with spinal bifida. In: Rekate HL, editor. Comprehensive Management of Spina Bifida. Boca Raton, FL, CRC Press; 1991. pp. 1–20.
7)

Rekate HL. Neurosurgical mangement of the child with spinal bifida. In: Rekate HL, editor. Comprehensive Management of Spina Bifida. Boca Raton, FL, CRC Press; 1991. pp. 93–112.
8)

Rekate HL. Selecting patients for endoscopic third ventriculostomy. Neurosurg Clin N Am. 2004;15:39–49. doi: 10.1016/S1042-3680(03)00074-3.
9)

Oi S. Classification of hydrocephalus: critical analysis of classification categories and advantages of “Multi-categorical Hydrocephalus Classification” (Mc HC). Childs Nerv Syst. 2011 Oct;27(10):1523-33. doi: 10.1007/s00381-011-1542-6. Epub 2011 Sep 17. Review. PubMed PMID: 21928018.

External ventricular drainage complications

External ventricular drainage complications

Acutely increased intracranial pressure (ICP) is frequently managed by external ventricular drainage (EVD). This procedure is life-saving but marred by a high incidence of complications. It has recently been indicated that bolt-connected external ventricular drainage (BC-EVD) compared to the standard technique of tunnelled EVD (T-EVD) may result in less complications 1).

Intracranial hemorrhage

Infection

Misplacement

Obstruction

Ventricular catheter obstruction.


The purpose of this study was to investigate whether a surgeon’s experience affects the associated complication rate. Methods This retrospective study included all adult patients undergoing EVD insertion at a single centre between July 2013 and June 2015. Medical records were retrieved to obtain details on patient demographics, surgical indication, risk factors for infection and use of anticoagulants or antiplatelets. Surgeon experience, operative time, intraoperative antibiotic prophylaxis, need for revision surgery and EVD associated infection were examined. Information on catheter tip position and radiological evidence of intracranial haemorrhage was obtained from postoperative imaging. Results A total of 89 patients were included in the study. The overall infection, haemorrhage and revision rates were 4.8%, 7.8% and 13.0% respectively, with no significant difference among surgeons of different experience. The mean operating time for patients who developed an infection was 22 minutes while for those without an infection, it was 33 minutes (p=0.474). Anticoagulation/antiplatelet use did not appear to increase the rate of haemorrhage. The infection rate did not correlate with known risk factors (eg diabetes and steroids), operation start time (daytime vs out of hours) or duration of surgery although intraoperative (single dose) antibiotic prophylaxis seemed to reduce the infection rate. There was also a correlation between longer duration of catheterisation and increased risk of infection. Conclusions This is the first study demonstrating there is no significant difference in complication rates between surgeons of different experience. EVD insertion is a core neurosurgical skill and junior trainees should be trained to perform it 2).


Patients were prospectively enrolled in the CLEAR III trial after placement of an EVD for obstructive intraventricular hemorrhage and randomized to receive recombinant tissue-type plasminogen activator or placebo. We counted any detected new hemorrhage (catheter tract hemorrhage or any other distant hemorrhage) on computed tomography scan within 30 days from the randomization. Meta-analysis of published series of EVD placement was compiled with STATA software.

Growing or unstable hemorrhage was reported as a cause of exclusion from the trial in 74 of 5707 cases (1.3%) screened for CLEAR III. The first 250 patients enrolled have completed adjudication of adverse events. Forty-two subjects (16.8%) experienced ≥1 new bleeds or expansions, and 6 of 250 subjects (2.4%) suffered symptomatic hemorrhages. Eleven cases (4.4%) had culture-proven bacterial meningitis or ventriculitis.

Risks of bleeding and infection in the ongoing CLEAR III trial are comparable to those previously reported in EVD case series. In the present study, rates of new bleeds and bacterial meningitis/ventriculitis are very low despite multiple daily injections, blood in the ventricles, the use of thrombolysis in half the cases, and generalization to >60 trial sites 3).

References

1)

Jensen TS, Carlsen JG, Sørensen JC, Poulsen FR. Fewer complications with bolt-connected than tunneled external ventricular drainage. Acta Neurochir (Wien). 2016 Aug;158(8):1491-4. doi: 10.1007/s00701-016-2863-8. Epub 2016 Jun 21. PubMed PMID: 27324657.
2)

Yuen J, Selbi W, Muquit S, Berei T. Complication rates of external ventricular drain insertion by surgeons of different experience. Ann R Coll Surg Engl. 2018 Mar;100(3):221-225. doi: 10.1308/rcsann.2017.0221. Epub 2018 Jan 24. PubMed PMID: 29364007; PubMed Central PMCID: PMC5930101.
3)

Dey M, Stadnik A, Riad F, Zhang L, McBee N, Kase C, Carhuapoma JR, Ram M, Lane K, Ostapkovich N, Aldrich F, Aldrich C, Jallo J, Butcher K, Snider R, Hanley D, Ziai W, Awad IA; CLEAR III Trial Investigators. Bleeding and Infection With External Ventricular Drainage: A Systematic Review in Comparison With Adjudicated Adverse Events in the Ongoing Clot Lysis Evaluating Accelerated Resolution of Intraventricular Hemorrhage Phase III (CLEAR-III IHV) Trial. Neurosurgery. 2015 Mar;76(3):291-301. doi: 10.1227/NEU.0000000000000624. PubMed PMID: 25635887; PubMed Central PMCID: PMC4333009.

Internal jugular vein stenosis

Internal jugular vein stenosis (IJVS) is gaining increasing attention from clinical researchers due to a series of confounding symptoms that impair the quality of life in affected individuals but cannot be explained by other well-established causes. In a study of Zhou et al.,from the Xuanwu Hospital, aimed to elucidate the clinical features, neuroimaging characteristics and pathogenesis of IJVS, and explore their possible correlations, in attempt to provide useful clues for clinical diagnosis and treatment. Forty-three eligible patients with unilateral or bilateral IJVS confirmed by contrast-enhanced magnetic resonance venography of the brain and neck were enrolled in a study. Magnetic resonance imaging along with magnetic resonance angiography or computed tomography angiography was applied to identify the radiological pattern of parenchymal or arterial lesions. Cerebral perfusion and metabolismwere evaluated by single-photon emission computed tomography (SPECT). Of the 43 patients (46.0 ± 16.0 years old; 30 female), 14 (32.6%) had bilateral and 29 had unilateral IJVS. The common clinical symptoms at admission were tinnitus (60.5%), tinnitus cerebri (67.6%), headache(48.8%), dizziness (32.6%), visual disorders (39.5%), hearing impairment (39.5%), neck discomfort (39.5%), sleep disturbance (60.5%), anxiety or depression (37.5%) and subjective memory impairment (30.2%). The presence of bilateral demyelination changes with cloudy-like appearance in the periventricular area and/or centrum semiovale was found in 95.3% (41/43) patients. SPECT findings showed that 92.3% (24/26) patients displayed cerebral perfusion and metabolism mismatch, depicted by bilaterally and symmetrically reduced cerebral perfusion and increased cerebral glucose consumption. IJVS may contribute to alterations in cerebral blood flow and metabolism, as well as white matter lesion formation, all of which may account for its clinical manifestations. 1).


Fifteen consecutive patients were screened from 46 patients suspected as IIH and were finally confirmed as isolated IJV stenosis. The stenotic IJV was corrected with stenting when the trans-stenotic mean pressure gradient (∆MPG) was equal to or higher than 5.44 cmH2 O. Dynamic magnetic resonance venography, computed tomographic venography and digital subtraction angiography of the IJV, ∆MPG, ICP, Headache Impact Test 6 and the Frisén papilledema grade score before and after stenting were compared.

All the stenotic IJVs were corrected by stenting. ∆MPG decreased and the abnormal collateral veins disappeared or shrank immediately. Headache, tinnitus, papilledema and ICP were significantly ameliorated at 14 ± 3 days of follow-up (all P < 0.01). At 12 ± 5.6 months of outpatient follow-up, headache disappeared in 14 out of 15 patients (93.3%), visual impairments were recovered in 10 of 12 patients (83.3%) and tinnitus resolved in 10 out of 11 patients (90.9%). In 12 out of 15 cases, the Frisén papilledema grade scores declined to 1 (0-2). The stented IJVs in all 15 patients kept to sufficient blood flows on computed tomographic venography follow-up without stenting-related adverse events.

Non-thrombotic IJV stenosis may be a potential etiology of IIH. Stenting seems to be a promising option to address the issue of intracranial hypertension from the etiological level, particularly after medical treatment failure 2).


Previous magnetic resonance imaging studies have shown abnormalities of the internal jugular veins in patients with thoracic outlet syndrome (TOS), but this finding has largely been ignored. We, thus, prospectively performed diagnostic brachiocephalic venograms in all patients with diagnosed neurogenic TOS from April 2008 to December 2011 (mean age, 42.6; r, 16-68; 77.8% women and 22.2% men). Stenosis of the left internal jugular vein, left subclavian vein, right internal jugular vein, and right subclavian vein were assessed, and significant stenoses of these vessels were seen in 63.49%, 65.08%, 60.32%, and 68.25% of patients, respectively. Internal jugular vein stenosis was not present in 23.81%, present unilaterally in 28.57%, and present bilaterally in 47.62% of patients. Subclavian vein stenosis was not present in 17.46%, present unilaterally in 28.57%, and present bilaterally in 53.97% of patients. Phi coefficients of correlation were 0.067 between left internal jugular vein and left subclavian vein stenoses, 0.061 between right internal jugular vein and right subclavian vein stenoses, and 0 between any internal jugular vein and any subclavian vein stenoses, indicating there is no correlation between jugular vein stenosis and subclavian vein stenosis in these patients. We conclude that right and left internal jugular vein stenosis is common in patients with neurogenic TOS symptoms. Treatment of internal jugular vein stenosis could potentially benefit these patients, and the implications of these findings warrant further study 3).

Clinical trials

References

1)

Zhou D, Ding J, Asmaro K, Pan L, Ya J, Yang Q, Fan C, Ding Y, Ji X, Meng R. Clinical Characteristics and Neuroimaging Findings in Internal Jugular Venous Outflow Disturbance. Thromb Haemost. 2019 Jan 3. doi: 10.1055/s-0038-1676815. [Epub ahead of print] PubMed PMID: 30605919.
2)

Zhou D, Meng R, Zhang X, Guo L, Li S, Wu W, Duan J, Song H, Ding Y, Ji X. Intracranial hypertension induced by internal jugular vein stenosiscan be resolved by stenting. Eur J Neurol. 2018 Feb;25(2):365-e13. doi: 10.1111/ene.13512. Epub 2017 Dec 7. PubMed PMID: 29114973.
3)

Ahn SS, Miller TJ, Chen SW, Chen JF. Internal jugular vein stenosis is common in patients presenting with neurogenic thoracic outlet syndrome. Ann Vasc Surg. 2014 May;28(4):946-50. doi: 10.1016/j.avsg.2013.12.009. Epub 2014 Jan 21. PubMed PMID: 24462538.
× How can I help you?
WhatsApp WhatsApp us
%d bloggers like this: