A Case of Posterior Circulation Embolism Due to a Subtype of Bow Hunter's Syndrome Diagnosed by Non-Invasive Examination.

Bow hunter's syndrome is the mechanical compression of the vertebral artery due to cervical rotation, resulting in ischemic symptoms in the vertebrobasilar artery territory. However, some cases present without typical symptoms and exhibit compression of the non-dominant side of the vertebral artery. We encountered a case of posterior circulation embolism due to a subtype of bow hunter's syndrome in a 74-year-old man. Although the right vertebral artery was not visualized on time-of-flight magnetic resonance angiography in the neutral position, duplex ultrasonography and time-of-flight magnetic resonance angiography in the left cervical rotation position showed blood flow in the right vertebral artery. In this case, blood flow in the contralateral vertebral artery was normal, and typical bow hunter's syndrome symptoms did not occur. In a case of posterior circulation embolism with undetermined etiology, wherein the routine duplex ultrasonography and time-of-flight magnetic resonance angiography results were inconclusive, additional testing with head positioning led to the diagnosis of a subtype of bow hunter's syndrome.

[Varicella-zoster meningoencephalitis and vasculitis after treatment with amenamevir to herpes zoster in the trigeminal nerve area].

A 78-year-old woman was diagnosed with herpes zoster in the first branch of the trigeminal nerve and was treated with amenamevir. Subsequently, she was hospitalized for postherpetic neuralgia. Fever and unconsciousness were observed, and a diagnosis of varicella-zoster virus meningoencephalitis and vasculitis was made. In addition to the antithrombotic therapy, she was treated with intravenous acyclovir and steroid pulse therapy; however, her unconsciousness persisted. Amenamevir was not transferrable to the spinal fluid and resulted in an incomplete treatment of herpes zoster in the cerebral nerve region, suggesting that this case may be related to the severe course of the disease.

[A case of cerebral infarction in young adult resulting in thrombotic occlusion of vertebral artery due to repeated contact stimulation of cervical rotation accompanied to systemic malformations such as atlantoaxial subluxation and atlas dysplasia].

A 23-year-old man admitted to our hospital with headache and dysarthria. Head MRI showed multiple acute cerebral infarctions in the right posterior circulation. Atlantoaxial dislocation, atlas dysplasia and thrombotic occlusion of right vertebral artery (VA), and blood flow disruption due to cervical rotation was observed. The axial dental process bordered to the right VA, and repeated contact stimulation by cervical rotation may cause intimal damage resulting in thrombotic occlusion. In this case, various systemic malformations such as atrial septal defect, atlas posterior arch hypoplasia, bovine left common carotid bifurcation malformation, double inferior vena cava and horseshoe kidney may have been congenital syndromes. Atlantoaxial dislocation may be an important and under-recognized cause of stroke in young adults.

[Amyloid ß related angitis without marked leukoencephalopathy].

An 86-year-old woman was admitted to our hospital with headache and acute detarioration of consciousness. Cerebral microbleeds (CMBs) dominated the occipital lobe on the head MRI, revealing white matter lesions. It was accompanied by gadolinium (Gd) imaging effect in the leptomeninges and some CMBs. She was clinically diagnosed with amyloid ß-related vasculitis and a good outcome was obtained with steroid therapy. Even when symptoms re-exacerbated, exacerbation of the contrast effect of CMBs was observed, but no white matter lesions appeared, and leptomeningeal enhancement did not change remarkably throughout the entire course.

Long-term poor rapport, lack of spontaneity and passive social withdrawal related to acute post-infectious encephalitis: a case report.

INTRODUCTION: Post-infectious encephalitis/encephalopathy is a neurological syndrome that sometimes develops following common viral or bacterial infections. The most common form is acute disseminated encephalomyelitis (ADEM). ADEM is a demyelinating disease of the central nervous system that typically presents as a monophasic disorder associated with multifocal neurologic symptoms and encephalitis. Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is another type of severe autoimmune disorder, characterized by seizures, movement disorders and psychiatric symptoms. In general, the prognosis and long-term outcomes of both ADEM and anti-NMDAR encephalitis are favorable. Most patients show complete, albeit slow recovery over a period of one to 2 years. There are few reports of patients with these disorders showing long-term residual psychiatric symptoms. CASE PRESENTATION: We report the case of a 16-year-old Japanese male who suffered from acute post-infectious encephalitis. The patient followed an atypical recovery course, in that he showed poor rapport, lack of spontaneity and passive social withdrawal for more than 2 years after the initial symptoms. While treatment with small doses of antipsychotic drugs at the hospital had no effect on the symptoms, the patient recovered gradually over a prolonged period of five or so years. CONCLUSIONS: This case report suggests that a type of acute post-infectious encephalitis with demyelinating features, possibly ADEM or anti-NMDAR encephalitis, or an overlap between the two, can cause a prodrome of behavioral changes and long-term residual psychiatric symptoms for many months, although it is eventually associated with a good prognosis.

Evaluation of luminal and vessel wall abnormalities in subacute and other stages of intracranial vertebrobasilar artery dissections using the volume isotropic turbo-spin-echo acquisition (VISTA) sequence: a preliminary study.

OBJECTIVE: To evaluate the utility of 3D variable refocusing flip-angle volume isotropic turbo-spin-echo acquisition (VISTA) imaging, using a 1.5-T MRI unit, which can minimize flow artifacts, due to its sequence-endogenous flow-void capability, in the diagnosis of intracranial vertebrobasilar artery dissection (VAD). MATERIAL AND METHODS: The presence of intimal flaps, intramural hematomas, vessel dilatations and abnormal vessel enhancements were evaluated on T1-weighted VISTA images from 18 VAD patients with 20 dissected arteries (15 subacute and five at other stages). Additional gadolinium-enhanced T1VISTA images were available for 13 patients. The frequency of flow artifacts on T1VISTA imaging in 70 non-dissected arteries in VAD patients and 12 control subjects was also evaluated. Furthermore, in 13 and eight patients, contrast-enhanced three-dimensional (CE3D) imaging with spoiled gradient-recalled (SPGR) acquisition in steady state and electrocardiographically gated black-blood (BB) T1-weighted imaging (T1WI) were evaluated to compare visualization of false lumens. RESULTS: Intimal flaps, intramural hematomas and dilatations were identified on T1VISTA images in 65% (13/20), 55% (11/20) and 90% (18/20) of VADs, respectively. Abnormal vessel enhancement was recognized in 100% (15/15) of VADs on contrast-enhanced T1VISTA images. Only four normal arteries showed small, thin, linear artifacts. Compared with CE3D-SPGR imaging, T1VISTA imaging depicted false lumens more conspicuously in seven VADs (P=0.02). T1VISTA also revealed intimal flaps and hematomas as did BB T1WI. CONCLUSION: T1VISTA imaging may be useful for diagnosing VAD at subacute stages, as it can reveal vessel wall and lumen abnormalities with a minimum of flow artifacts.

Reversible cerebral vasoconstriction syndrome in a patient with Takayasu's arteritis.

We herein present the first reported case of reversible cerebral vasoconstriction syndrome (RCVS) in Takayasu's arteritis (TA), in a patient with severe thunderclap headache and generalized tonic-clonic seizure. Magnetic resonance imaging and angiography revealed posterior reversible encephalopathy syndrome, followed by severe vasoconstriction in multiple arteries. RCVS should be included in the differential diagnosis of thunderclap headache attacks with radiologic intracranial vascular abnormalities in connective tissue diseases, including TA.

Plaque vulnerability in internal carotid arteries with positive remodeling.

BACKGROUND: This study aimed to evaluate the efficacy of assessing positive remodeling for predicting future stroke events in the internal carotid artery. We therefore assessed narrowing of the carotid artery lumen using multidetector-row computer tomography (MDCT) angiography and carotid plaque characteristics using black-blood (BB) magnetic resonance (MR). METHODS: We retrospectively selected 17 symptomatic and 11 asymptomatic lesions with luminal narrowing >50%. We compared remodeling parameters of luminal stenosis (remodeling ratio, RR/remodeling index, RI) using MDCT and MR intensities of atherosclerotic plaque contents using the BB technique (relative signal intensity, rSI). We also confirmed the validity of the relationship between MR intensity and atherosclerotic plaque contents by histology. The levels of biological markers related to vessel atherosclerosis were measured. RESULTS: Plaque lesions with positive remodeling in carotid arteries were associated with a significantly higher prevalence of stroke compared with plaques with negative remodeling (p < 0.05). Radiologic and histologic analyses determined that plaques with positive remodeling had higher signal intensities (with respect to their lipid-rich content or to hemorrhage) compared with negative remodeling (correlation coefficients: RI and rSI, r = 0.41, p < 0.05; RR and rSI, r = 0.50, p < 0.05). Levels of biological markers, including high-sensitivity C-reactive protein, hemoglobin A1C, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol, were not useful for predicting stroke events. CONCLUSIONS: The results of this study suggest that the combined analysis of RR, RI and rSI could potentially help to predict future stroke events.

[A case of hypertrophic cranial pachcymeningitis in a patient with lymphocytic hypophysitis].

We report a 67-year-old man of lymphocytic hypophysitis complicated by hypertrophic cranial pachcymeningitis. The hypophysitis presenting with central diabetes insipidus caused isolated adrenocorticotropic hormone (ACTH) deficiency after three years and two months since the onset of his illness. Moreover he suffered from left cavernous sinus syndrome after four years. Brain gadolinium (Gd) enhanced MRI, which was obtained in 2001, showed only enhancement of the pituitary stalk. However, brain Gd enhanced MRI, performed four years later, showed not only a remarkable thickening and enhancement of the pituitary stalk but also abnormal enhancement of the lesion in the left cavernous sinus. In addition, it showed diffuse thickening and enhancement of the dura mater. This clinical course suggested that chronic inflammation of the pituitary had spread to the dura mater, a clinical condition differing from parasellar chronic inflammatory disease (PSCID). In addition, because diffuse thickening and enhancement of the dura mater was present, it was likely that lymphocytic hypophysitis was complicated by hypertrophic cranial pachcymeningitis due to autoimmune reactions. We should carefully observe cases of lymphocytic hypophysitis and assess change over time in the dura mater of the whole brain by Gd enhanced MRI.

[A case of transient blindness due to severe stenosis of the internal carotid artery with persistent primitive hypoglossal artery (PPHA)].

We report a patient having transient blindness due to severe stenosis of the internal carotid artery (ICA) with persistent primitive hypoglossal artery (PPHA). This 73 year-old man was admitted because of the transient visual impairment. At first, he had bilateral blindness for a several minutes and after that the right amaurosis continued for an hour. MRI showed an old lacunar infarction of the right caudate nucleus. Carotid duplex ultrasonography and conventional angiography demonstrated severe stenosis of the origin of the right ICA, and PPHA was arising from the right ICA at the level of 2nd cervical spine. The left ICA was normal. Because of the aplasia of the right vertebral artery and hypoplasia of the left vertebral artery, almost all blood flow of the basilar artery was supplied from the right ICA via PPHA. We considered that transient ischemia of both the bilateral posterior cerebral arteries and the right ocular artery occurred due to stenosis of the right ICA which branching PPHA. When ischemic neurological symptoms of multiple vascular territories occurr at the same time, we often think that ischemic mechanism was cardiogenic embolism. But we should recognize that stenosis of the ICA with PPHA cause the complex neurological deficits.

[An autopsy case of purulent meningitis, presenting high signals in subarachnoid space and ventricles in diffusion weighted images (DWIs)].

A 79-year-old, bedridden woman with an untreated colon cancer, developed abrupt disturbance of consciousness and high fever. Brain MRI showed significant high signals in the subarachnoid space and ventricles in diffusion-weighted images (DWIs), and she died on the same day. At autopsy, much exudate was found over the base of the brain, leading to a diagnosis of purulent meningitis. On histological findings, inflammatory cell infiltration was significantly restricted within the subarachnoid space, but not into the brain parenchyma. This case report demonstrated that high signals in subarachnoid space and ventricles in DWIs may be very useful for diagnosis of purulent meningitis.