Bilateral medial medullary stroke: A rare stroke syndrome masquerading as myasthenia crisis in a young diabetic lady.

Bilateral medial medullary stroke is a rare stroke syndrome. The clinical presentation of bilateral medial medullary stroke is heterogenous and often overlaps with other non-stroke neurology emergencies such as Guillain-Barrésyndrome, myasthenic crisis and acute vestibular syndrome, leading to misdiagnosis. We wish to present a case of a young lady with type 1 diabetes mellitus, who had presented with subacute neuromuscular weakness which was erroneously treated as myasthenic crisis. Her case was subsequently diagnosed as bilateral medial medullary stroke, following evolving clinical signs and magnetic resonance imaging (MRI) findings of a heart-shaped abnormality at the rostral medulla. This rare stroke syndrome represented a diagnostic challenge which necessitated a strong clinical suspicion and an urgent MRI scan of the brain for prompt diagnosis to enable appropriate treatment initiation.

"Basilar Web" Causing Basilar Branch Infarction.

We present a young patient with no vascular risk factors with a basilar branch infarction secondary to a shelf-like filling defect of the basilar artery. This defect was present and unchanged on repeat imaging and determined to be most consistent with a basilar web. Similar to carotid webs, a basilar web is believed to be an area of focal intimal fibroplasia that increases the risk of brainstem infarction. Focal fibroplasia of the posterior circulation should be considered when evaluating young adults with posterior circulation strokes of otherwise undetermined cause.

[Bilateral Wallerian degeneration of pontocerebellar fibres secondary to pontine infarction]. / Degeneracion walleriana bilateral de haces pontocerebelosos secundaria a infarto protuberancial.

TITLE: Degeneracion walleriana bilateral de haces pontocerebelosos secundaria a infarto protuberancial.

First autopsy analysis of a neovascularized arterial network induced by indirect bypass surgery for moyamoya disease: case report.

The object of this study was to analyze the pathology of collateral vessels newly induced by indirect bypass surgery for moyamoya disease (MMD). An autopsy analysis was conducted on a 39-year-old woman with MMD who had died of a brainstem infarction. The patient had undergone bilateral indirect bypass surgeries 22 years earlier. Sufficient revascularization via bilateral external carotid arterial systems was confirmed by cerebral angiography before her death. Macroscopic observation of the operative areas revealed countless meandering vessels on the internal surface of the dura mater connected with small vessels on the brain surface and in the subpial brain tissue. Notably, microscopic analysis of these vessels revealed the characteristic 3-layer structure of an arterial wall. This autopsy analysis was the first to confirm that indirect bypass surgery had induced the formation of a new arterial network (arteriogenesis) and that this network had been maintained for more than 20 years to compensate for the chronic cerebral ischemia caused by the MMD.

Late-onset radiation-induced vasculopathy and stroke in a child with medulloblastoma.

We report a case of a 15-year-old boy who presented to our institution with left-sided weakness and slurred speech. He had a history of medulloblastoma diagnosed at 3 years of age, status postsurgical resection and craniospinal radiation. Magnetic resonance imaging (MRI) of brain revealed a right paramedian pontine infarction, suspected secondary to late-onset radiation-induced vasculopathy of the vertebrobasilar system. Radiation to the brain is associated with increased incidence of ischemic stroke. Clinicians should have a high index of suspicion for stroke when these patients present with new neurologic symptoms.

[Chronic tuberculous meningitis presenting recurrent brainstem infarction without features of meningitis].

A 44-year-old woman with a history of transient right hemiparesis presented with personality change. One year later, she was admitted with ophthalmoparesis, dysarthria and regression phenomenon. MRI indicated acute infarction of the paramedian region of the midbrain and a nodular lesion in the interpeduncular fossa with contrast enhancement. Two years later, the patient was admitted with sudden onset of right hemiplegia. MRI showed acute infarction in the left side of the pons, diffuse brain atrophy, and abnormal contrast enhancement in the nodular lesion of interpeduncular fossa and leptomeninges of the ventral pons. MR angiography revealed that cerebral main tracts were intact, and cerebrospinal fluid analysis revealed mild pleocytosis and slightly elevated protein levels. Cervical lymph node biopsy demonstrated caseating granuloma with acid-fast bacilli. The patient was diagnosed with chronic tuberculous meningitis, even though tuberculous bacilli were not detected on polymerase chain reaction (PCR) or in culture. Antituberculous medication resulted in radiological resolution and neurological improvement. Although the patient had mild headache and pyrexia at the first admission, no signs of meningeal irritation were confirmed throughout the clinical course. We suspect that a paucity of tuberculous bacilli released from the tuberculous foci in the meninges to the subarachnoid space caused prolonged clinical course and lack of meningeal irritation signs.

Basilar artery bending length, vascular risk factors, and pontine infarction.

BACKGROUND: Patients exhibiting basilar artery (BA) curvature (not dolichoectasia) are at an increased risk of posterior circulation ischemic stroke. In this study, pontine infarction patients were analyzed to assess the effect of BA bending length (BL) together with other vascular factors on pontine stroke risk. METHODS: Acute pontine infarction patients were divided into BA bending and non-BA bending groups by magnetic resonance angiography (MRA). Patients with BA bending who reported symptoms of dizziness or vertigo but who had not suffered brain infarction constituted the control group. The diameter of the vertebral artery (VA) and BL were measured using MRA. Based on the bilateral VA diameter data in vertebral artery-dominant (VAD) patients, the study participants were divided into three classes for VA diameter: class one, 0.30-0.80 mm (20 cases); class two, 0.81-1.37 mm (20 cases); and class three, 1.38-3.24 mm (20 cases). The measured BL in VAD cases allowed division of patients into three levels for BL: level one, 1.02-2.68 mm (21 cases); level two, 2.69-3.76 mm (20 cases); and level three, 3.77-7.25 mm (19 cases). Vascular risk factors were compared among the three groups. Correlations of BL and VA diameter differences were studied, and multivariate analysis was applied to search for predictors of ischemic stroke in BA bending patients. RESULTS: Among BA bending, non-BA bending, and control groups, VA dominance (VAD) proved to be a significant differentiator. For all three groups, a patient age of ≥ 65 years, the occurrence of hypertension, smoking, high homocysteine levels, high cholesterol, and a history of type 2 diabetes, were all statistically significant factors (P<0.05). After adjusting for other relevant factors, multivariate analysis shows that BL of level 3 was an independent risk factor for pontine infarction (OR=2.74; 95% CI, 1.27 to 4.48). Both BL and diameter differences between the VAs were positively correlated with risk with statistical significance (r=0.769, P<0.001). CONCLUSIONS: Both BL and diameter differences between the VAs are positively correlated with the risk of pontine infarction. When BA bending was coupled with other vascular risk factors, the probability of pontine infarction increased. BA bending with a BL greater than 3.77 mm was an independent predictor of pontine infarction.

Pattern of voiding dysfunction after acute brainstem infarction.

BACKGROUND: The purpose of this study is to compare the patterns of voiding dysfunction according to the locations of brainstem lesions. METHODS: Between November 2008 and December 2011, a total of 30 patients participated in this study. All 30 subjects, consisting of 16 men and 14 women, aged between 41 and 82 years (mean age, 63.0±11.0 years) underwent a urodynamic study within 7 days after the onset of a stroke. RESULTS: Twenty-one (70%) patients had a pontine lesion and 9 (30%) had a medullary lesion. Fourteen of these patients (46.7%) had bladder storage disorder, 7 patients (23.3%) had bladder emptying disorder, and 9 patients (30%) had a normal report. Five of the patients who had a medullary lesion (55.6%) had bladder emptying disorder, whereas only 2 patients who had a pontine lesion (9.5%) had bladder emptying disorder. Thirteen patients who had a pontine lesion (61.9%) showed bladder storage disorder. DISCUSSION: The descending pathway from the midbrain tegmentum is inhibitory, and the pathway from the pontine tegmentum is stimulatory. Because of their location pontine lesions could disrupt the descending fibers of the midbrain tegmentum and medullary lesions could disrupt the descending fibers of the pontine tegmentum.

Occurrence and clinicotopographical correlates of brainstem infarction in patients with diabetes mellitus.

BACKGROUND: The goal of the study was to clarify the association between diabetes mellitus (DM) and brainstem infarctions (BSIs) and to investigate the clinicotopographic characteristics of BSIs in patients with diabetes. METHODS: Data were retrospectively reviewed for 1026 consecutive patients admitted to our hospital because of acute cerebral infarctions from January 2004 to August 2010. Acute symptomatic BSIs were explored on radiologic images and classified into multiple infarctions with BSIs, multifocal BSIs, and monofocal BSIs. Isolated BSIs were further classified based on the vertical distribution into midbrain, pontine, and medullary infarctions, and on the horizontal distribution into anterior-dominant, posterior-dominant, and anterior/posterior BSIs. Neurologic symptoms of BSIs and clinical background were compared between DM and non-DM patients. RESULTS: The prevalence of BSIs was 2.6-fold higher (P < .0001) in DM patients. Logistic regression analysis including age, sex, smoking, previous stroke, atrial fibrillation, other cardiac diseases, hypertension, hyperlipidemia, and DM showed that DM was independently associated with BSIs (odds ratio [OR] 2.814; 95% confidence interval [CI] 1.936-4.090; P < .0001). Compared with non-DM patients, DM patients showed more frequent monofocal BSIs (P < .0001) and multifocal BSIs (P = .0296). Monofocal BSIs (n = 114) more frequently involved the pons (P < .0001) and medulla (P = .0212). Anterior-dominant BSIs (P < .0001) were more common in DM patients than in non-DM patients. Symptoms of BSIs included more frequent motor paresis (P = .0180) and less frequent diplopia (P = .0298) in DM patients than in non-DM patients. CONCLUSIONS: DM is important in the development of BSIs, and the associated clinical characteristics include more frequent motor paresis and less frequent diplopia.

Bruns-Cushing nystagmus due to hypertensive unilateral paramedian pontine base infarction.

Bruns-Cushing nystagmus is unusually rare and is known to be related with cerebellopontine angle tumor. A 32-year-old male patient came to our emergency department 3 times because of dizziness, right upper limb ataxia, hypertension, and Bruns-Cushing nystagmus. Magnetic resonance imaging demonstrated left paramedian pontine infarction. In conclusion, Bruns-Cushing nystagmus not only indicates a cerebellopontine angle tumor but may also be associated with pontine infarction.

Fluctuating gustatory disturbance and ophthalmodynia heralding the onset of a paramedian pontine infarction.

Lasting taste disturbance has been previously reported as a consequence of brainstem infarction, but there are no previous reports of transient gustatory sensations preceding the onset of stroke. Ophthalmodynia, presenting as "salt-and-pepper" eye pain, has been reported rarely. We present a 58-year-old right-handed woman who had fluctuating ophthalmodynia and taste disturbance immediately preceding a left paramedian pontine infarction. We discuss the neuroanatomical basis of taste in reference to this presentation.

Two patients with rare causes of Weber's syndrome.

We report two patients with rare causes of Weber's syndrome and review the relevant literature. The first patient presented with Weber's syndrome caused by a partially thrombosed giant aneurysm of the posterior cerebral artery. The second patient was an immunocompetent patient who presented with progressive hemiparesis and subsequently developed Weber's syndrome. Primary central nervous system lymphoma (PCNSL) was eventually diagnosed. To our knowledge, the association between Weber's syndrome and PCNSL is rare.

Spontaneous unilateral brainstem infarction in Swiss mice.

Spontaneous vestibular syndrome in mice, characterized clinically by head tilt, circling or rolling, can be caused by otitis media, arteritis or central nervous system lesions. Postmortem examination of eleven non-inbred Swiss mice submitted for necropsy due to acute onset of vestibular signs revealed lesions consistent with brainstem infarction. The lesions were characterized by unilateral, well-demarcated areas of necrosis, malacia, and gliosis, with variable amounts of hemorrhage, in the lateral aspect of the medulla and caudal pons. The affected area included the medial, lateral and superior vestibular nuclei, the facial nucleus and the spinal trigeminal nucleus. While vestibular disease secondary to otitis media, periarteritis, and central nervous system neoplasia has been reported in many mouse strains, these unilateral brainstem infarctions were only seen in Swiss mice. These lesions share features with Wallenberg's Lateral Medullary Syndrome, the most common type of brainstem infarct in humans.

Microscopic polyangiitis presenting with medullary infarct.

Microscopic polyangiitis is a small vessel vasculitis which is rarely associated with ischemic stroke. Cerebrovascular disease has rarely been reported in connection with this disease. It may cause fatal hemorrhage, hemorrhagic conversion and multiple lacunar infarcts. We report here a 55-year-old woman with left medullary oblangata infarction without any symptoms of microscopic polyangiitis. During hospitalization, retinal ischemia, mononeuritis multiplex and pulmonary infiltration developed. Sural nerve biopsy was concomitant with small vessel vasculitis. Elevated CRP and sedimentation and positive P-ANCA led to confirmation of a diagnosis of microscopic polyangiitis. Our patient is a rare case of microscopic polyangiitis presenting with medullary infarction. Although the characteristics of this disease are well-known, the first symptom can be a medullary infarction, which has not been reported in literature before.

Medial medullary infarction identified by diffusion-weighted magnetic resonance imaging.

OBJECTIVE: To elucidate the frequency and clinical profiles of patients with medial medullary infarction (MMI) identified by diffusion-weighted MRI (DWI). METHODS: We assessed the frequency, radiological findings, etiology and clinical features of MMI detected by DWI from our single-center registry of acute ischemic patients. RESULTS: Thirty patients (1.5% of 2,014 with ischemic stroke) had MMI, including isolated unilateral MMI in 26 patients. Lesions were located by DWI in the rostral medulla of 25 patients (83%). Culprit infarcts that were undetectable by DWI in 6 (38%) of 16 patients who were assessed within 24 h after onset were later confirmed as MMI. The major etiological mechanism was small artery occlusion (SAO; 19 patients) and the median initial National Institutes of Health Stroke Scale score was 4 (interquartile range: 3-4.75). The most frequent symptom was contralateral hemiparesis (27 patients). None of the patients fulfilled the classical Dejerine Triad. Twenty-two patients (73%) had a modified Rankin Scale score of ≤2 at 3 months. A patient developed transient ischemic attack within 3 months; none developed recurrent stroke. CONCLUSIONS: Rostral medullary infarction with mild neurological deficits resulting from SAO is relatively frequent. Because emergency DWI within 24 h could not detect MMI in one third of the patients, this type of infarction could be misdiagnosed as capsular/pontine lacunae or other neurological disorders.

Unilateral headache associated with a pontine infarction.

Brain stem structures are implicated in the generation of migraine and other types of headache. The patient described herein had chronic left hemicranial headaches associated with a left pontine infarction.

Death in custody and undiagnosed central neurocytoma.

Fatal brain tumors are often diagnosed well before death. Rarely, they present as sudden and unexpected death. Most of these undiagnosed brain tumors are gliomas. Death in custody is uncommon and can be caused by natural diseases. These are mainly associated with the cardiovascular system and rarely by cancers such as primary intracranial tumors.We present a case of a 55-year-old man who died while in police custody. At the autopsy there was a previously undiagnosed large soft intraventricular tumor. Cerebrospinal fluid flow was obstructed causing a raised intracranial pressure which resulted in displacement of the pons, and death. Microscopy and immunohistochemistry confirmed a central neurocytoma.

Experimental model of brainstem stroke in rabbits via endovascular occlusion of the basilar artery.

BACKGROUND: Basilar artery thrombosis remains a significant clinical problem, and no reproducible animal model has been established to study the stroke within the vertebrobasilar distribution. We report a study designed to pilot test a novel model of brainstem stroke in rabbits, created by selective endovascular occlusion of the basilar artery. METHODS: Basilar artery occlusion was induced in 8 New Zealand white rabbits by injection of the autologous clot through the microcatheter positioned within the distal vertebral artery. Animals were divided into subgroups (I and II) based on the length of produced ischemia (3 and 6 hours, respectively). Magnetic resonance (MR) imaging of the brain and MR angiography of the intracranial vessels were performed before the procedure, and at 3 hours after induced ischemia for groups I and II, with continued imaging up to 6 hours for group II, with diffusion-weighted images acquired approximately every 30 minutes. Animals were killed at the end of the 3-hour (group I) or 6-hour (group II) ischemia time. RESULTS: Brainstem stroke was successfully induced in all animals, with pathological changes documented in all cases. The earliest changes of ischemia on MR diffusion-weighted images were identified at only 4.5 hours of basilar artery occlusion. CONCLUSION: These results suggest that a reproducible model of brainstem stroke can be induced in rabbits using selective endovascular occlusion of the basilar artery. The availability of such a model, integrated with state-of-the-art imaging techniques, holds promise for preclinical investigations of emergent therapeutic approaches in stroke.