Moyamoya Disease Diagnosis

Moyamoya Disease Diagnosis

Diagnosis of Moyamoya disease requires bilateral symmetrical stenosis or occlusion of the terminal portion of the internal carotid arterys (ICA)s as well as the presence of dilated collateral vessels at the base of the brain 1). (If unilateral, the diagnosis is considered questionable, 2) and these cases may progress to bilateral involvement).

Other characteristic findings include:

  1. stenosis/occlusion starting at the termination of ICA and at origins of ACA and MCA

  2. abnormal vascular network in the region of BG (intraparenchymal anastomosis).

  3. transdural anastomosis(rete mirabile), AKA “vault moyamoya.”Contributing arteries: anterior falcial, middle meningeal, ethmoidal, occipital, tentorial, STA

  4. moyamoya collaterals may also form from the internal maxillary artery via ethmoid sinus to the forebrain in the frontobasal region.

Work-up in suspected cases typically begins with a non-enhanced head CT. Up to 40% of ischemic cases have normal CT. Low-density areas (LDAs) may be seen, usually confined to cortical and subcortical areas (unlike atherosclerotic disease or acute infantile hemiplegia which tend to have LDAs in basal ganglia as well). LDAs tend to be multiple and bilateral, especially in the PCA distribution (poor collaterals), and are more common in children.

Magnetic resonance imaging for Moyamoya Disease Diagnosis.

In addition to helping to establish the diagnosis, angiography also identifies suitable vessels for revascularization procedures and unearths associated aneurysms. The angiography-related complication rate is higher than with atherosclerotic occlusive disease. Avoid dehydration prior to and hypotension during the procedure. Six angiographic stages of MMD are described by Suzuki and Takaku 3) that tend to progress up until adolescence and stabilize by age 20.

1 stenosis of suprasellar ICA, usually bilateral

2 development of moyamoya vessels at the base of the brain; ACA MCA & PCA dilated

3 increasing ICA stenosis & prominence of moya-moya vessels (most cases diagnosed at this stage); maximal basal moyamoya

4 entire circle of Willis and PCAs occluded, extracranial collaterals start to appear, moyamoya vessels begin to diminish

5 further progression of stage 4

6 complete absence of moyamoya vessels and major cerebral arteries.

Non-specific in the adult. Juvenile cases: high-voltage slow waves may be seen at rest, predominantly in the occipital and frontal lobes. Hyperventilation produces a normal buildup of monophasic slow waves (delta-bursts) that return to normal 20–60 seconds after hyperventilation. In >50%of cases, after or sometimes continuous with buildup is a second phase of slow waves (this characteristic finding is called “rebuild up”) which are more irregular and slower than the earlier waves, and usually, normalize in ≤10 minutes 4).

CBF is decreased in children with MMD, but relatively normal in adults. There is a shift of CBF from the frontal to the occipital lobes 5) probably reflecting the increasing dependency of CBF on the posterior circulation. Children with MMD have impaired autoregulation of CBF to blood pressure and CO2 (with more impairment of vasodilatation in response to hypercapnia or hypotension than vasoconstriction in response to hypocapnia or hypertension) 6). Xenon (Xe-133) CT can identify areas of low perfusion. Repeating the study after an acetazolamide challenge (which causes vasodilatation) evaluates the reserve capacity of CBF and can identify areas of “steal” which are at high risk of future infarction.

Ultrasound parameters are independently correlated with ipsilateral cerebral stroke in patients with Moyamoya disease (MMD). Ultrasound provides a new way to identify stroke in MMD patients. Future prospective cohort studies are needed to verify the clinical value of ultrasound in identifying patients with MMD at high risk of stroke 7).


1)

Smith ER, Scott RM. Surgical management of moyamoya syndrome. Skull Base. 2005; 15:15–26
2)

Nishimoto A. Moyamoya Disease. Neurol Med Chir. 1979; 19:221–228
3)

Suzuki J, Takaku A. Cerebrovascular “moyamoya” disease. Disease showing abnormal net-like vessels in base of brain. Arch Neurol. 1969 Mar;20(3):288-99. PubMed PMID: 5775283.
4)

Kodama N, Aoki Y, Hiraga H, et al. Electroencephalographic Findings in Children with Moyamoya Disease. Arch Neurol. 1979; 36:16–19
5)

Ogawa A, Yoshimoto T, Suzuki J, Sakurai J. Cerebral Blood Flow in Moyamoya Disease. Part 1. Correlation with Age and Regional Distribution. Acta Neurochir. 1990; 105:30–34
6)

Ogawa A, Nakamura N, Yoshimoto T, Suzuki J. Cerebral Blood Flow in Moyamoya Disease. Part 2. Autoregulation and CO2 Response. Acta Neurochir. 1990; 105:107–111
7)

Zheng S, Wang F, Cheng L, Li R, Zhang D, He W, Zhang W. Ultrasound parameters associated with stroke in patients with moyamoya disease: a logistic regression analysis. Chin Neurosurg J. 2022 Oct 11;8(1):32. doi: 10.1186/s41016-022-00300-5. PMID: 36221122.

Spontaneous intracranial hypotension diagnosis

Spontaneous intracranial hypotension diagnosis

Spontaneous intracranial hypotension diagnosis have evolved due to improved understanding of spontaneous intracranial hypotension pathophysiology and implementation of advanced myelography techniques. Farnsworth et al. synthesized recent updates and contextualize them in an algorithm for diagnosis and treatment of SIH, highlighting basic principles and points of practice variability or continued debate. This discussion includes finer points of SIH diagnosis, spontaneous cerebrospinal fluid fistula classification systems, less common types and variants of CSF leaks, Brain MRI Bern scoring for intracranial hypotension diagnosis, potential spontaneous intracranial hypotension complications, key technical considerations, and positioning strategies for different types of Dynamic CT myelography. 1).


The diagnosis of spontaneous intracranial hypotension or cerebrospinal fluid (CSF) hypovolemia syndrome requires a high index of suspicion and meticulous history taking, demonstration of low CSF pressure and/or neuroimaging features.


Diagnostic criteria of headache attributed to low cerebrospinal fluid pressure (per IHS Classification (ICHD-III)):

  1. any headache that developed in temporal relation to low CSF pressure or cerebrospinal fluid fistula or has led to its discovery

  2. low CSF pressure (< 6 cm of water) and/or evidence of CSF leakage on imaging

  3. not better accounted for by another ICHD-III

Radiographic criteria are not required for diagnosis since no characteristic findings are seen in 20– 25% of patients.

The median delay from presentation to the diagnosis of SIH is 4 months.

This delay may be detrimental to patient outcomes. Therefore, brain MRI without and with contrast is recommended in patients with new-onset orthostatic headaches.


The diagnosis requires a high index of suspicion and meticulous history taking, demonstration of low CSF pressure and/or neuroimaging features.

Intracranial hypotension is associated with simple clinical presentation, orthostatic headache, and characteristic MRI findings. Misdiagnosed, it leads to unnecessary procedures 2).

The primary diagnostic factor relies on confirmation of cerebrospinal fluid leakage based on reduced spinal fluid pressure. Determining the specific leakage site is the most important issue for effective treatment but remains a difficult task. Although CT myelogram, radionuclide cisternography, and MRI are commonly performed in the diagnosis of CSF hypovolemia, these techniques can rarely identify the precise leakage site.

Therefore, an epidural blood patch is performed in the lumbar spine in many cases.

The identification of the site of CSF leak in the spinal canal can be very challenging. In some cases, the site cannot be identified.

Magnetic resonance imaging for intracranial hypotension diagnosis

Continuous intracranial pressure monitoring is definitive for documenting abnormally negative intracranial pressures.

A 31-year-old male, presented with subacute onset moderate occipital and sub-occipital headaches precipitated by upright posture and relieved on recumbency and neck pain for 2 years. There was no trauma, cranial/spinal surgery. Clinical examination was normal and CSF opening pressure and laboratory study were normal. Magnetic resonance imaging (MRI) brain showed thin subdural hygroma. Another patient, 41-year-old male presented with 1 month of subacute onset severe bifrontal throbbing orthostatic headaches (OHs). CSF opening pressure was normal. Contrast MRI brain showed the presence of bilateral subdural hygromas, diffuse meningeal enhancement, venous distension, sagging of the brain, and tonsillar herniation. We report two cases of “spontaneous OHs” with normal CSF pressures who were successfully treated with epidural blood patching after poor response to conservative management 3).

Repeated measurements of the optic nerve sheath diameter (ONSD) using B-mode sonography were performed before treatment initiation, during medical treatment, and during a course of repeated placement of epidural blood patches.

On admission, transorbital sonography revealed a decreased ONSD of 4.1 mm on the right and 4.3 mm on the left side. After 8 months of treatment with caffeine and computed tomography-guided epidural blood patches a gradual distension of the ONSD into the normal range was bilaterally observed (right: 5.2 mm; left: 5.3 mm).

The ultrasound-based evaluation of the optic nerve sheath may be helpful in detecting CSF hypovolemia and for determination of treatment effects. This report should be seen as a basis for future investigations on the sonographic assessment of the optic nerve sheath in diagnosis and treatment of intracranial hypotension 4).

Symptomatic patients with SIH showed a significant decrease of ONSD, as assessed by ultrasound, when changing from the supine to the upright position. Ultrasound assessment of the ONSD in two positions may be a novel, non-invasive tool for the diagnosis and follow-up of SIH and for elucidating the pathophysiology of SIH 5).


1)

Farnsworth PJ, Madhavan AA, Verdoorn JT, Shlapak DP, Johnson DR, Cutsforth-Gregory JK, Brinjikji W, Lehman VT. Spontaneous intracranial hypotension: updates from diagnosis to treatment. Neuroradiology. 2022 Nov 7. doi: 10.1007/s00234-022-03079-5. Epub ahead of print. PMID: 36336758.
2)

Louhab N, Adali N, Laghmari M, Hymer WE, Ben Ali SA, Kissani N. Misdiagnosed spontaneous intracranial hypotension complicated by subdural hematoma following lumbar puncture. Int J Gen Med. 2014 Jan 15;7:71-3. doi: 10.2147/IJGM.S48656. eCollection 2014. PubMed PMID: 24470768; PubMed Central PMCID: PMC3896286.
3)

Hassan KM, Prakash S, Majumdar SS, Banerji A. Two cases of medically-refractory spontaneous orthostatic headaches with normal cerebrospinal fluid pressures responding to epidural blood patching: Intracranial hypotension versus hypovolemia and the need for clinical awareness. Ann Indian Acad Neurol. 2013 Oct;16(4):699-702. doi: 10.4103/0972-2327.120461. PubMed PMID: 24339614; PubMed Central PMCID: PMC3841635.
4)

Bäuerle J, Gizewski ER, Stockhausen Kv, Rosengarten B, Berghoff M, Grams AE, Kaps M, Nedelmann M. Sonographic assessment of the optic nerve sheath and transorbital monitoring of treatment effects in a patient with spontaneous intracranial hypotension: case report. J Neuroimaging. 2013 Apr;23(2):237-9. doi: 10.1111/j.1552-6569.2011.00640.x. Epub 2011 Sep 1. PubMed PMID: 21883624.
5)

Fichtner J, Ulrich CT, Fung C, Knüppel C, Veitweber M, Jilch A, Schucht P, Ertl M, Schömig B, Gralla J, Z’Graggen WJ, Bernasconi C, Mattle HP, Schlachetzki F, Raabe A, Beck J. Management of spontaneous intracranial hypotension – Transorbital ultrasound as discriminator. J Neurol Neurosurg Psychiatry. 2016 Jun;87(6):650-5. doi: 10.1136/jnnp-2015-310853. Epub 2015 Aug 18. PubMed PMID: 26285586; PubMed Central PMCID: PMC4893146.

Epilepsy diagnosis

Epilepsy diagnosis

The accurate diagnosis of seizures is essential as some patients will be misdiagnosed with epilepsy, whereas others will receive an incorrect diagnosis. Indeed, errors in diagnosis are common, and many patients fail to receive the correct treatment, which often has severe consequences

Imaging is pivotal in the evaluation and management of patients with seizure disorders.

Positron emission tomography (PET) is the most commonly performed interictal functional neuroimaging technique that may reveal a focal hypometabolic region concordant with seizure onset. Single photon emission computed tomography (SPECT) studies may assist the performance of ictal neuroimaging in patients with pharmacoresistant focal epilepsy being considered for neurosurgical treatment 1).

Elegant structural neuroimaging with magnetic resonance imaging (MRI) may assist in determining the etiology of focal epilepsy and demonstrating the anatomical changes associated with seizure activity. The high diagnostic yield of MRI to identify the common pathological findings in individuals with focal seizures including mesial temporal sclerosis, vascular anomalies, Low-grade glioma and malformations of cortical development has been demonstrated.

Positron emission tomography (PET) imaging in epilepsy is an in vivo technique that allows the localization of a possible seizure onset zone (SOZ) during the interictal period. Stereo-electro-encephalography (SEEG) is the gold standard to define the SOZ. The objective of aresearch was to evaluate the accuracy of PET imaging in localizing the site of SOZ compared with SEEG.

Seven patients with refractory temporal lobe epilepsy (Ep) and 2 healthy controls (HC) underwent 2 PET scans, one with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) and another with 2′-[18F]fluoroflumazenil (FFMZ), acquired 1 day apart. FDG was acquired for 10 min (static scan) 1 h after administration. An FFMZ scan was acquired for 60 min from radiopharmaceutical administration in a dynamic mode. Each brain PET image was segmented using a standard template implemented in PMOD 3.8. The pons was used as the reference region for modeling of the nondisplaceable binding potential (BPND)for FFMZ, and to obtain uptake ratios for FDG. SEEG studies of patients were performed as a part of their surgical evaluation to define the SOZ.

Well-defined differences between HC and Ep were found with both radiopharmaceuticals, showing the utility to identify abnormal brain regions using quantitative PET imaging. Lateralization of the SOZ findings by PET (lower uptake/binding in a specific brain hemisphere) matched in 86% for FFMZ and 71% for FDG with SEEG data.

Quantitative PET imaging is an excellent complementary tool that matches reasonably well with SEEG to define SOZ in presurgical evaluation 2).

Cerebrospinal fluid analysis for epilepsy

Automatic seizure detection.

Results of a cross-sectional study suggest that genetic testing of individuals with epilepsy may be materially associated with clinical decision-making and improved patient outcome3).


1)

Cendes F, Theodore WH, Brinkmann BH, Sulc V, Cascino GD. Neuroimaging of epilepsy. Handb Clin Neurol. 2016;136:985-1014. doi: 10.1016/B978-0-444-53486-6.00051-X. PubMed PMID: 27430454.
2)

Avendaño-Estrada A, Velasco F, Velasco AL, Cuellar-Herrera M, Saucedo-Alvarado PE, Marquez-Franco R, Rivera-Bravo B, Ávila-Rodríguez MA. Quantitative Analysis of [18F]FFMZ and [18F]FDG PET Studies in the Localization of Seizure Onset Zone in Drug-Resistant Temporal Lobe Epilepsy. Stereotact Funct Neurosurg. 2019 Nov 13:1-9. doi: 10.1159/000503692. [Epub ahead of print] PubMed PMID: 31722358.
3)

McKnight D, Morales A, Hatchell KE, Bristow SL, Bonkowsky JL, Perry MS, Berg AT, Borlot F, Esplin ED, Moretz C, Angione K, Ríos-Pohl L, Nussbaum RL, Aradhya S; ELEVIATE Consortium, Haldeman-Englert CR, Levy RJ, Parachuri VG, Lay-Son G, de Montellano DJD, Ramirez-Garcia MA, Benítez Alonso EO, Ziobro J, Chirita-Emandi A, Felix TM, Kulasa-Luke D, Megarbane A, Karkare S, Chagnon SL, Humberson JB, Assaf MJ, Silva S, Zarroli K, Boyarchuk O, Nelson GR, Palmquist R, Hammond KC, Hwang ST, Boutlier SB, Nolan M, Batley KY, Chavda D, Reyes-Silva CA, Miroshnikov O, Zuccarelli B, Amlie-Wolf L, Wheless JW, Seinfeld S, Kanhangad M, Freeman JL, Monroy-Santoyo S, Rodriguez-Vazquez N, Ryan MM, Machie M, Guerra P, Hassan MJ, Candee MS, Bupp CP, Park KL, Muller E 2nd, Lupo P, Pedersen RC, Arain AM, Murphy A, Schatz K, Mu W, Kalika PM, Plaza L, Kellogg MA, Lora EG, Carson RP, Svystilnyk V, Venegas V, Luke RR, Jiang H, Stetsenko T, Dueñas-Roque MM, Trasmonte J, Burke RJ, Hurst ACE, Smith DM, Massingham LJ, Pisani L, Costin CE, Ostrander B, Filloux FM, Ananth AL, Mohamed IS, Nechai A, Dao JM, Fahey MC, Aliu E, Falchek S, Press CA, Treat L, Eschbach K, Starks A, Kammeyer R, Bear JJ, Jacobson M, Chernuha V, Meibos B, Wong K, Sweney MT, Espinoza AC, Van Orman CB, Weinstock A, Kumar A, Soler-Alfonso C, Nolan DA, Raza M, Rojas Carrion MD, Chari G, Marsh ED, Shiloh-Malawsky Y, Parikh S, Gonzalez-Giraldo E, Fulton S, Sogawa Y, Burns K, Malets M, Montiel Blanco JD, Habela CW, Wilson CA, Guzmán GG, Pavliuk M. Genetic Testing to Inform Epilepsy Treatment Management From an International Study of Clinical Practice. JAMA Neurol. 2022 Oct 31. doi: 10.1001/jamaneurol.2022.3651. Epub ahead of print. PMID: 36315135.
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