Clinical and neuroimaging precursors in cerebral amyloid angiopathy: impact of the Boston criteria version 2.0.

BACKGROUND AND PURPOSE: Although the Boston criteria version 2.0 facilitates the sensitivity of cerebral amyloid angiopathy (CAA) diagnosis, there are only limited data about precursor symptoms. This study aimed to determine the impact of neurological and imaging features in relation to the time of CAA diagnosis. METHODS: Patients diagnosed with probable CAA according to the Boston criteria version 1.5, treated between 2010 and 2020 in our neurocentre, were identified through a keyword search in our medical database. Neuroimaging was assessed using Boston criteria versions 1.5 and 2.0. Medical records with primary focus on the clinical course and the occurrence of transient focal neurological episodes were prospectively evaluated. RESULTS: Thirty-eight out of 81 patients (46.9%) exhibited transient focal neurological episodes, most often sensory (13.2%) or aphasic disorders (13.2%), or permanent deficits at a mean time interval of 31.1 months (SD ±26.3; range 1-108 months) before diagnosis of probable CAA (Boston criteria version 1.5). If using Boston criteria version 2.0, all patients receiving magnetic resonance imaging (MRI) met the criteria for probable CAA, and diagnosis could have been made on average 44 months earlier. Four patients were younger than 50 years, three of them with supporting pathology. Cognitive deficits were most common (34.6%) at the time of diagnosis. CONCLUSIONS: Non-haemorrhagic MRI markers enhance the sensitivity of diagnosing probable CAA; however, further prospective studies are proposed to establish a minimum age for inclusion. As the neurological overture of CAA may occur several years before clinical diagnosis, early clarification by MRI including haemosensitive sequences are suggested.

Acute Disseminated Encephalomyelitis and Acute Encephalitis Following Vaccination Against SARS-CoV-2: Two Case Reports and Review of Literature.

The spectrum of severe neurological complications following COVID-19 vaccination includes cerebrovascular events, inflammatory diseases of the CNS, cranial and peripheral nerve involvement and muscle affections. Post-vaccinal acute disseminated encephalomyelitis (ADEM) and acute encephalitis are rare. We report on a patient suffering from acute encephalitis and another with post-vaccinal monophasic ADEM. Beside imaging features typical for acute autoimmune associated inflammation, cranial MRI disclosed also transient haemorrhagic signal alterations in some cerebral lesions. To our best knowledge, this has not been mentioned before in literature. Competing causes were excluded by extensive laboratory investigations including serial CSF analysis. In line with the literature, repeated iv high-dosage corticosteroid therapy resulted in impressive improvement of neurological symptoms in both patients.

Reliability of Instant Messaging-Based Evaluation of Brain Imaging in Acute Stroke.

BACKGROUND: The use of instant messenger applications among physicians has become common in acute stroke management, especially in developing countries. Photos or video sequences of brain computed tomography (CT) scans are being sent to receive real-time support in assessing radiological findings. We analyzed whether instant messaging-based evaluation is precise enough to extract relevant information from the images. METHODS: In this prospective study, anonymized videos and photos of CT and CT angiography scans of patients with symptoms of acute stroke were recorded from the diagnostic monitor using a smartphone. Two neurologists and 2 neuroradiologists performed evaluation of the images using WhatsApp. The gold standard was set by 2 experienced neuroradiologists who evaluated the CT images with their full radiological equipment. Statistical analysis included the calculation of Cohen kappa (κ). RESULTS: A total of 104 brain images (derived from 81 patients) were included. All 4 raters performed with a perfect (κ=1) interobserver reliability in diagnosing intracerebral hemorrhage. For subarachnoid hemorrhage, interobserver reliability was slightly lower (raters 1, 2, and 3, κ=1; rater 4, κ=0.88). For diagnosing stroke mimics, interobserver reliability showed considerable variations (κ between 0.32 and 1). Alberta Stroke Program Early CT Score differences overall were comparable between raters and did not exceed 3 to 4 points without noticeable outliers. All raters performed with a moderate-to-substantial interobserver reliability for detecting large vessel occlusions (κ=0.48 in rater 1, κ=0.62 in rater 2, and κ=0.63 in raters 3 and 4). CONCLUSIONS: Stroke neurologists can reliably extract information on intracerebral hemorrhage from CT images recorded via smartphone and sent through instant messaging tools. Remote diagnosis of early infarct signs and stroke mimics was less reliable. We developed a standard for the acquisition of images, taking data protection into account.

Clazosentan for Improvement of Time to Peak Perfusion in Patients with Angiographically Confirmed Severe Vasospasm.

BACKGROUND: Clazosentan, an endothelin-1 receptor antagonist, has been shown to prevent the development of large vessel angiographic vasospasm after aneurysmal subarachnoid hemorrhage. We hypothesized that clazosentan can improve cerebral perfusion for territories affected by angiographically confirmed vasospasm. METHODS: The REVERSE study (REversal of Vasospasm with clazosEntan post-aneuRysmal Subarachnoid hEmorrhage) was a prospective multicenter open-label pilot study of adult patients with aneurysmal subarachnoid hemorrhage who received intravenous clazosentan after developing moderate to severe angiographic vasospasm. Using the radiographic data from the REVERSE study and additional retrospective radiographic data from our tertiary medical center, we compared the impact of intravenous clazosentan with intraarterial vasodilator therapy (medical standard of care) on vasospasm reversal using time to peak perfusion (TTPP; the time interval between the peak opacification of contrast dye in the main artery supplying an anatomically defined territory and the parenchymal phase when the dye is diffusely present in the brain parenchyma). RESULTS: Both intravenous clazosentan (n = 7 vessels) and intraarterial vasodilator therapy (n = 11 vessels) resulted in a statistically significant improvement in TTPP at 24 h post intervention, when compared with the TTPP just prior to intervention for territories with angiographically confirmed severe vasospasm in the proximal arteries at baseline (linear mixed-effect model, p = 0.02). The clazosentan and intraarterial vasodilator therapy groups exhibited no statistically significant interaction term [time x treatment group (medical standard of care vs. clazosentan)] in our model (p = 0.71), suggesting similar temporal course of two therapies. CONCLUSIONS: In our small pilot study, intravenous clazosentan administered for at least 24 h had an effect comparable with that of intraarterial vasodilator therapy in reversing angiographically confirmed severe vasospasm. Our results may indicate that clazosentan, in an appropriately selected patient cohort, could offer a noninvasive approach for alleviating vasospasm.

Toxic Spongiform Leukoencephalopathy After Intravenous Heroin Abuse: Unusual But Important Differential Diagnosis of Acute Impairment of Consciousness.

Abuse of heroin vapour inhalation known as "chasing the dragon" is associated with toxic spongiform leukoencephalopathy. However, similar clinical and imaging findings may occur also after intravenous heroin abuse. We report on a 32-year-old male suffering from extensive toxic spongiform leukoencephalopathy after intravenous heroin abuse resulting in acute impairment of consciousness and a global state of confusion. MRI disclosed broad and nearly symmetrical diffusion restriction of the supratentorial white matter indicating cytotoxic oedema. In an emergency setting, differential diagnosis of acute impairment of consciousness and broad symmetrical white matter lesions in neuroimaging should also include toxic leukoencephalopathy due to intravenous heroin application.

Neuroradiological and clinical features in ophthalmoplegia.

PURPOSE: Especially in acute onset of ophthalmoplegia, efficient neuroradiological evaluation is necessary to assist differential diagnosis, clinical course, and treatment options. METHODS: Different manifestations of ophthalmoplegia are explained and illustrated by characteristic neuroradiological and clinical findings. RESULTS: To present those ophthalmoplegic disorders in a clear manner, this review refers to different neuroanatomical structures and compartments. From neuroophthalmological point of view, diseases going ahead with ophthalmoplegia can be divided into (1) efferent infranuclear/peripheral disturbances involving oculomotor cranial nerves, (2) conjugate gaze abnormalities due to internuclear or supranuclear lesions, and (3) diseases of the extraocular eye muscles or their impairment due to intraorbital pathologies. CONCLUSION: The knowledge of the relationship between neurological findings in ophthalmoplegia and involved neuroanatomical structures is crucial, and neuroradiology can be focused on circumscribed anatomical regions, using optimized investigation protocols.

Complication rate of intraarterial treatment of severe cerebral vasospasm after subarachnoid hemorrhage with nimodipine and percutaneous transluminal balloon angioplasty: Worth the risk?

BACKGROUND AND PURPOSE: Delayed cerebral ischemia (DCI) is a complication of aneurysmal subarachnoid hemorrhage (SAH). Arterial cerebral vasospasm (CVS) is discussed as the main pathomechanism for DCI. Due to positive effects of per os nimodipine, intraarterial nimodipine application is used in patients with DCI. Further, percutaneous transluminal balloon angioplasty (PTA) is applied in focal high-grade spasm of intracranial arteries. However, clinical benefits of those techniques are unconfirmed in randomized trials so far, and complications might occur. We analyzed the occurrence of new infarcts in patients with severe CVS treated intra-arterially to assess benefits and risks of those techniques in a large single-center collective. MATERIALS AND METHODS: All imaging and clinical data of 88 patients with CVS after SAH and 188 procedures of intraarterial nimodipine infusion and additional PTA in selected cases (18 patients, 20 PTA procedures) treated at our institution were reviewed. In the event of new infarcts after endovascular treatment of CVS, infarct patterns were analyzed to determine the most probable etiology. RESULTS: Fifty-three percent of patients developed new cerebral infarction after intraarterial nimodipine and additional PTA in selected cases. Hereunder 47% were caused by persisting CVS. In 6% of patients, 3% of procedures respectively, new infarcts occurred due to complications of the intraarterial treatment including thromboembolism and arterial dissection. Of those, 3% of patients, 2% of procedures respectively, were assigned to thrombembolic complications of digital substraction angiography for intraarterial nimodipine. 17% of all patients treated with PTA (3/18=17%) showed infarction as a complication of PTA (15% of all PTA procedures). In 1% of patients, etiology of new infarction remained unclear. CONCLUSION: Ischemic complications occur in about 6% of patients treated intraarterially for CVS, 3% of procedures respectively. Further, to date a benefit for patients treated with this therapy could not be proven. Therefore, intraarterial treatment of CVS should be performed only in carefully selected cases.

Osmotic Demyelination Syndrome due to Severe Hyponatremia Mimicking Hypoxic Encephalopathy.

Hyponatremia and its rapid correction is a well-known cause of osmotic demyelination most commonly affecting the pons. We report on a case of severe hyponatremia likely due to psychogenic polydipsia resulting in hypotonic hyperhydration with resulting cortical laminar necrosis on initial imaging, mimicking hypoxic brain damage. Pontine myelinolysis became apparent on follow-up imaging, illustrating the diagnostic challenges of extrapontine manifestations of severe hyponatremia.

[Bilateral hippocampal primary CNS lymphoma: unusual differential diagnosis of rapid progressive dementia]. / Bilaterales hippocampales primäres ZNS-Lymphom: ungewöhnliche Differentialdiagnose eines rasch progredienten dementiellen Syndroms.

We report on a 63-year old man suffering from rapid progressive dementia due to bilateral hippocampal primary CNS lymphoma. Early diagnosis especially in secondary dementia is essential because of potentially treatable aetiologies with regression of cognitive and behaviour abnormalities. Characteristic imaging findings especially in inflammatory and neoplastic lesions affecting the hippocampal structures are discussed.

Spinal cord ischemia: aetiology, clinical syndromes and imaging features.

INTRODUCTION: The purpose of this study was to analyse MR imaging features and lesion patterns as defined by compromised vascular territories, correlating them to different clinical syndromes and aetiological aspects. METHODS: In a 19.8-year period, clinical records and magnetic resonance imaging (MRI) features of 55 consecutive patients suffering from spinal cord ischemia were evaluated. RESULTS: Aetiologies of infarcts were arteriosclerosis of the aorta and vertebral arteries (23.6%), aortic surgery or interventional aneurysm repair (11%) and aortic and vertebral artery dissection (11%), and in 23.6%, aetiology remained unclear. Infarcts occurred in 38.2% at the cervical and thoracic level, respectively, and 49% of patients suffered from centromedullar syndrome caused by anterior spinal artery ischemia. MRI disclosed hyperintense pencil-like lesion pattern on T2WI in 98.2%, cord swelling in 40%, enhancement on post-contrast T1WI in 42.9% and always hyperintense signal on diffusion-weighted imaging (DWI) when acquired. CONCLUSION: The most common clinical feature in spinal cord ischemia is a centromedullar syndrome, and in contrast to anterior spinal artery ischemia, infarcts in the posterior spinal artery territory are rare. The exclusively cervical location of the spinal sulcal artery syndrome seems to be a likely consequence of anterior spinal artery duplication which is observed preferentially here.

Thalamo-mesencephalic Branches of the Posterior Cerebral Artery: a 3D Rotational Angiography Study.

PURPOSE: The thalamo-mesencephalic (TM) branches of the posterior cerebral artery (PCA) supply critical structures. Previous descriptions of these vessels are inconsistent and almost exclusively rely on cadaver studies. We aimed to provide a neuroradiological description of TM vessels in vivo based on routine 3D rotational angiographies (3D-RA). METHODS: We analyzed 3D-RAs of 58 patients with pathologies remote from the PCA. PCA-origins were considered. Delineation, origin and number of branches of the collicular artery (CA), the accessory CA (ACA), the posterior thalamoperforating artery (PTA), the thalamogeniculate artery (TGA), and the posterior medial (PMCA) and lateral (PCLA) choroid arteries were assessed. The PTAs were categorized based on Percheron's suggested classification. RESULTS: A CA was identified in 84%, an ACA in 20%. The PTA was delineated in 100%. In 27%, PTA anatomy had features of several Percheron types (n = 7) or vessels emanating from a net like origin (n = 9). 26% had a type IIb PTA. A fetal type PCA origin with hypoplastic ipsilateral P1 was observed in 5 cases with type IIa (n = 2) or type IIb (n = 3) PTAs originating from contralateral P1. The TGA was identified in 85% of patients, with ≥ 2 branches in 67%. The PMCA was delineable in 41%, the PLCA in 100%. CONCLUSION: The prevalence of a proper "Artery of Percheron" type IIb PTA seems to be higher than previously reported. A fetal type P1-origin may be predictive of a type IIa/b PTA emanating from contralateral P1. 3D-RA may be useful for planning PCA interventions, as impairment of TM branches is a severe risk.

Cerebral Superficial Siderosis : Etiology, Neuroradiological Features and Clinical Findings.

Superficial siderosis (SS) of the central nervous system constitutes linear hemosiderin deposits in the leptomeninges and the superficial layers of the cerebrum and the spinal cord. Infratentorial (i) SS is likely due to recurrent or continuous slight bleeding into the subarachnoid space. It is assumed that spinal dural pathologies often resulting in cerebrospinal fluid (CSF) leakage is the most important etiological group which causes iSS and detailed neuroradiological assessment of the spinal compartment is necessary. Further etiologies are neurosurgical interventions, trauma and arteriovenous malformations. Typical neurological manifestations of this classical type of iSS are slowly progressive sensorineural hearing impairment and cerebellar symptoms, such as ataxia, kinetic tremor, nystagmus and dysarthria. Beside iSS, a different type of SS restricted to the supratentorial compartment can be differentiated, i.e. cortical (c) SS, especially in older people often due to cerebral amyloid angiopathy (CAA). Clinical presentation of cSS includes transient focal neurological episodes or "amyloid spells". In addition, spontaneous and amyloid beta immunotherapy-associated CAA-related inflammation may cause cSS, which is included in the hemorrhagic subgroup of amyloid-related imaging abnormalities (ARIA). Because a definitive diagnosis requires a brain biopsy, knowledge of neuroimaging features and clinical findings in CAA-related inflammation is essential. This review provides neuroradiological hallmarks of the two groups of SS and give an overview of neurological symptoms and differential diagnostic considerations.

Cervical myelitis: a practical approach to its differential diagnosis on MR imaging.

BACKGROUND: Differential diagnosis of non-compressive cervical myelopathy encompasses a broad spectrum of inflammatory, infectious, vascular, neoplastic, neurodegenerative, and metabolic etiologies. Although the speed of symptom onset and clinical course seem to be specific for certain neurological diseases, lesion pattern on MR imaging is a key player to confirm diagnostic considerations. METHODS: The differentiation between acute complete transverse myelitis and acute partial transverse myelitis makes it possible to distinguish between certain entities, with the latter often being the onset of multiple sclerosis. Typical medullary MRI lesion patterns include a) longitudinal extensive transverse myelitis, b) short-range ovoid and peripheral lesions, c) polio-like appearance with involvement of the anterior horns, and d) granulomatous nodular enhancement prototypes. RESULTS AND CONCLUSION: Cerebrospinal fluid analysis, blood culture tests, and autoimmune antibody testing are crucial for the correct interpretation of imaging findings. The combination of neuroradiological features and neurological and laboratory findings including cerebrospinal fluid analysis improves diagnostic accuracy. KEY POINTS: · The differentiation of medullary lesion patterns, i. e., longitudinal extensive transverse, short ovoid and peripheral, polio-like, and granulomatous nodular, facilitates the diagnosis of myelitis.. · Discrimination of acute complete and acute partial transverse myelitis makes it possible to categorize different entities, with the latter frequently being the overture of multiple sclerosis (MS).. · Neuromyelitis optica spectrum disorders (NMOSD) may start as short transverse myelitis and should not be mistaken for MS.. · The combination of imaging features and neurological and laboratory findings including cerebrospinal fluid analysis improves diagnostic accuracy.. · Additional brain imaging is mandatory in suspected demyelinating, systemic autoimmune, infectious, paraneoplastic, and metabolic diseases..

Topographic Mapping of Isolated Thalamic Infarcts Using Vascular and Novel Probabilistic Functional Thalamic Landmarks.

PURPOSE: We aimed to re-evaluate the relationship between thalamic infarct (TI) localization and clinical symptoms using a vascular (VTM) and a novel functional territorial thalamic map (FTM). METHODS: Magnetic resonance imaging (MRI) and clinical data of 65 patients with isolated TI were evaluated (female n = 23, male n = 42, right n = 23, left n = 42). A VTM depicted the known seven thalamic vascular territories (VT: inferolateral, anterolateral, inferomedial, posterior, central, anteromedian, posterolateral). An FTM was generated from a probabilistic thalamic nuclei atlas to determine six functionally defined territories (FT: anterior: memory/emotions; ventral: motor/somatosensory/language; medial: behavior/emotions/nociception, oculomotor; intralaminar: arousal/pain; lateral: visuospatial/somatosensory/conceptual and analytic thinking; posterior: audiovisual/somatosensory). Four neuroradiologists independently assigned diffusion-weighted imaging (DWI) lesions to the territories mapped by the VTM and FTM. Findings were correlated with clinical features. RESULTS: The most frequent symptom was a hemisensory syndrome (58%), which was not specific for any territory. A co-occurrence of hemisensory syndrome and hemiparesis had positive predictive values (PPV) of 76% and 82% for the involvement of the inferolateral VT and ventral FT, respectively. Thalamic aphasia had a PPV of 63% each for involvement of the anterolateral VT and ventral FT. Neglect was associated with involvement of the inferolateral VT/ventral FT. Interrater reliability for the assignment of DWI lesions to the VTM was fair (κ = 0.36), but good (κ = 0.73) for the FTM. CONCLUSION: The FTM revealed a greater reproducibility for the topographical assignment of TI than the VTM. Sensorimotor hemiparesis and neglect are predictive for a TI in the inferolateral VT/ventral FT. The hemisensory syndrome alone does not allow any topographical assignment.

Perfusion-diffusion mismatch in MRI to indicate endovascular treatment of cerebral vasospasm after subarachnoid haemorrhage.

INTRODUCTION: Endovascular treatments such as transluminal balloon angioplasty and intra-arterial nimodipine represent rescue therapy for cerebral vasospasm (CVS) after aneurysmal subarachnoid haemorrhage (SAH). Both indication and data regarding its efficacy in the prevention of cerebral infarct are, however, inconsistent. Therefore, an MR based perfusion weighted imaging/diffusion weighted imaging (PWI/DWI) mismatch was used to indicate this treatment and to characterise its effectiveness. METHODS: MRI was performed for suspicion of CVS. For quantitative evaluation, the brain was partitioned into 19 arbitrary segments of comparable volume. Segments with PWI/DWI mismatch were defined as 'segment at risk (SR)'. In these cases, MRI was followed by angiography (digital subtraction angiography (DSA)) including endovascular treatment. 48 ± 12 h after treatment, a second MRI was performed and the treatment was repeated if new or remaining SR were observed. Efficacy was classified as the percentage of reduced diameter of the proximal cerebral arteries on DSA following the treatment: mild (≥33%), moderate (34-66%) or severe (≥67%). RESULTS: 48 treatment cycles, each consisting of MRI, DSA and a second MRI, were performed in 25 patients. During these cycles, 95 SR were identified. The infarct rate was significantly higher in SR (37%) compared with segments without risk (4%). The infarct rate in SR was significantly reduced if mild proximal CVS could be achieved. In the case of persistent severe CVS, infarcts occurred in all SR. CONCLUSION: The present series suggests that PWI/DWI mismatch is predictive of the development of infarct in the case of CVS. The infarct rate could, however, be improved if proximal CVS was sufficiently reduced.

Stripe-like increase of rCBV beyond the visible border of glioblastomas: site of tumor infiltration growing after neurosurgery.

We observed a stripe-like pattern of regional cerebral blood volume (rCBV) increase in a defined region adjacent to the contrast enhancement (CE) on MRI of glioblastomas (GBM) that we defined as the "striate sign" (SS). We hypothesized that the SS marks infiltration of GBM outside the CE volume transforming into future CE tumor in the follow-up. T2*-weighted dynamic susceptibility-weighted CE (DSC)-MRI, and T1 and T2-weighted images (WI) of 16 patients with GBM were retrospectively evaluated in a baseline MRI performed before neurosurgery. In seven of these patients we also performed a (1)H MR spectroscopic imaging ((1)H MRSI). The regions of interest (ROI) delineating the SS were defined on rCBV maps for each patient. ROIs were overlaid on follow-up T1-WI and T2-WI MRI performed 3, 6, and 9 months after neurosurgery. Size and maximum signal intensity (max SI) of de novo CE within the area of the SS were analyzed. Statistical analysis was performed with the Friedman test (P < 0.05). In 15/16 patients de novo CE completely covered the area of the SS within nine months. Normalized max SI of de-novo CE of the 3, 6, and 9-months follow-up MR examinations were significantly higher than in the baseline MRI (P < 0.001). Normalized choline was increased within the SS in all patients with de novo CE (n = 6). De-novo CE appeared within the SS in all patients (96% of all slices). This implies that the SS might indicate the site of future CE tumor, which represents the area of tumor growth after neurosurgery.

Diagnostic approach in multiple sclerosis with MRI: an update.

Although neurological examination and medical history are the first and most important steps towards the diagnosis of multiple sclerosis (MS), MRI has taken a prominent role in the diagnostic workflow especially since the implementation of McDonald criteria. However, before applying those on MR imaging features, other diseases must be excluded and MS should be favoured as the most likely diagnosis. For the prognosis the earliest possible and correct diagnosis of MS is crucial, since increasingly effective disease modifying therapies are available for the different forms of clinical manifestation and progression. This review deals with the significance of MRI in the diagnostic workup of MS with special regard to daily clinical practice. The recommended MRI protocols for baseline and follow-up examinations are summarized and typical MS lesion patterns ("green flags") in four defined CNS compartments are introduced. Pivotal is the recognition of neurological aspects as well as imaging findings atypical for MS ("red flags"). In addition, routinely assessment of Aquaporin-4-IgG antibodies specific for neuromyelitis optica spectrum disorders (NMOSD) as well as the knowledge of associated lesion patterns on MRI is recommended. Mistaken identity of such lesions with MS and consecutive implementation of disease modifying therapies for MS can worsen the course of NMOSD.

Multicenter Prospective Analysis of Hypertrophic Olivary Degeneration Following Infratentorial Stroke (HOD-IS): Evaluation of Disease Epidemiology, Clinical Presentation, and MR-Imaging Aspects.

Introduction: Ischemic and hemorrhagic strokes in the brainstem and cerebellum with injury to the functional loop of the Guillain-Mollaret triangle (GMT) can trigger a series of events that result in secondary trans-synaptic neurodegeneration of the inferior olivary nucleus. In an unknown percentage of patients, this leads to a condition called hypertrophic olivary degeneration (HOD). Characteristic clinical symptoms of HOD progress slowly over months and consist of a rhythmic palatal tremor, vertical pendular nystagmus, and Holmes tremor of the upper limbs. Diffusion Tensor Imaging (DTI) with tractography is a promising method to identify functional pathway lesions along the cerebello-thalamo-cortical connectivity and to generate a deeper understanding of the HOD pathophysiology. The incidence of HOD development following stroke and the timeline of clinical symptoms have not yet been determined in prospective studies-a prerequisite for the surveillance of patients at risk. Methods and Analysis: Patients with ischemic and hemorrhagic strokes in the brainstem and cerebellum with a topo-anatomical relation to the GMT are recruited within certified stroke units of the Interdisciplinary Neurovascular Network of the Rhine-Main. Matching lesions are identified using a predefined MRI template. Eligible patients are prospectively followed up and present at 4 and 8 months after the index event. During study visits, a clinical neurological examination and brain MRI, including high-resolution T2-, proton-density-weighted imaging, and DTI tractography, are performed. Fiberoptic endoscopic evaluation of swallowing is optional if palatal tremor is encountered. Study Outcomes: The primary endpoint of this prospective clinical multicenter study is to determine the frequency of radiological HOD development in patients with a posterior fossa stroke affecting the GMT at 8 months after the index event. Secondary endpoints are identification of (1) the timeline and relevance of clinical symptoms, (2) lesion localizations more prone to HOD occurrence, and (3) the best MR-imaging regimen for HOD identification. Additionally, (4) DTI tractography data are used to analyze individual pathway lesions. The aim is to contribute to the epidemiological and pathophysiological understanding of HOD and hereby facilitate future research on therapeutic and prophylactic measures. Clinical Trial Registration: HOD-IS is a registered trial at https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00020549.

Extracerebellar MRI-lesions in ataxia telangiectasia go along with deficiency of the GH/IGF-1 axis, markedly reduced body weight, high ataxia scores and advanced age.

Ataxia telangiectasia (AT) is a rare autosomal recessive disorder characterized by progressive ataxia, neurodegeneration, immunodeficiency, and cancer predisposition. Pathoanatomical studies reported a degeneration of cerebellar Purkinje cells as the striking feature of the disease. Although recent studies suggested the involvement of extracerebellar structures such as the brainstem and basal ganglia, this has rarely been studied in human AT. Thus, we performed a detailed cliniconeuroradiological investigation of 11 AT patients, aged 8 to 26 years by collecting clinical neurological data, ataxia scores, growth status, body mass index (BMI), growth hormone (GH), and insulin-like-growth factor 1 (IGF-1) and correlated them to extracerebellar neuroimaging findings in human AT. Neuroimaging was done by cranial and spine magnetic resonance imaging (MRI) with T1- and T2-weighted spin-echo and fluid attenuated inversion recovery sequences. We compared clinical and neuroradiological findings of six patients with IGF-1 levels and BMI below the third percentile to five patients with normal IGF-1 serum levels and BMI above the third percentile. Three of the six first mentioned patients older than 20 years and two patients older than 12 years showed noticeable high Klockgether ataxia scores above 25 points. Three of these patients presented with marked hyperintense lesions in the cerebral white matter of T2-weighted MR images. Interestingly, all six patients suffered from marked spinal atrophy. Two of the patients presented with severe extra-pyramidal symptoms, but only one patient showed associated MRI abnormalities of the basal ganglia. MRI in patients with normal IGF-1 levels showed the expected cerebellar lesions in four patients, whereas spinal atrophy was found only in two patients. There was no affection of the cerebral white matter or basal ganglia in this group. We conclude that central cerebral white matter affection, spinal atrophy, and extrapyramidal symptoms are more often present in patients with pronounced deficiency of the GH/IGF-1 axis accompanied by markedly reduced body weight and high ataxia scores. This may point to a major role of IGF-1 and nutritional status in neuroprotective signaling.

MR angiography in patients with subarachnoid hemorrhage: adequate to evaluate vasospasm-induced vascular narrowing?

The diagnosis of cerebral vasospasm (CVS) following subarachnoid hemorrhage (SAH) is still challenging. We evaluate the accuracy of time of flight MR angiography (TOF-MRA) to assess the arterial diameters of the circle of Willis in SAH patients with suspected CVS. MR examinations (1.5 Tesla) including 3D TOF-MRA with maximum intensity projections (MIP) and digital subtraction angiography (DSA) were performed within 24 h in 21 patients with acute aneurysmal SAH and suspicion of CVS. Arterial diameters of the circle of Willis including the distal internal carotid artery (ICA) were measured as ratios to the extradural ICA in standard projections. The diagnosis of CVS was established by comparing the luminal size of baseline and follow-up DSA. The correlation between the arterial ratios measured on MIP angiograms and on follow-up DSA was assessed with Pearson's linear regression analysis. Arterial ratios on MIP angiograms were categorized as correct, overestimated, and underestimated compared to the ratios on follow-up DSA. Pearson's correlation coefficient between the ratios of MIP angiograms and DSA was r = 0.5799 and the regression coefficient was b = 0.4775. Highest correlation was found for the category of severe CVS (r = 0.8201). Of all MIP angiograms, 34.9% showed consistent results compared to the DSA, while 44.2% of MIP images overestimated the vascular narrowing. Standard MIP angiograms from TOF-MRA are not accurate to assess vascular narrowing in patients with suspected CVS after aneurysmal SAH. The multifocal arterial stenoses in CVS may induce severe changes in blood flow dynamics, which compromise the diagnostic accuracy of the TOF-MRA.