nan Yuichiro

In vivo detection of cortical microinfarcts on ultrahigh-field MRI.

Cortical microinfarcts (CMIs) are detected as small foci restricted to the cerebral cortex in autopsy brains. CMIs are thought to be caused by cerebral amyloid angiopathy (CAA) in the elderly and may be a risk for dementia. We aimed to visualize CMIs, which remain invisible on conventional MRI, using double inversion recovery (DIR) and 3‐dimensional fluid attenuated inversion recovery (3D‐FLAIR) on 3‐Tesla MRI.

Reversible stenosis of large cerebral arteries in a patient with combined Sjögren’s syndrome and neuromyelitis optica spectrum disorder

We report a 49-year-old woman with neuromyelitis optica (NMO) spectrum disorder coexisting with Sjögren’s syndrome (SS). She presented with acute brainstem symptoms and transverse myelitis. Brain MRI showed focal high signal intensity lesions in the hypothalamus and the pontine tegmentum on T2-weighted and FLAIR images. MRA revealed stenotic changes of the bilateral middle cerebral artery (MCA), posterior cerebral arteries (PCA) and basilar artery (BA). Spinal MRI revealed hyperintense lesions within the cord extending from the T4 to the T6 level on the T2-weighted image. The patient fulfilled the clinical criteria of primary SS. In addition, anti-AQP4 antibody which is highly specific for NMO was detected in the serum at the acute phase. The patient excellently responded to IVIg while methylprednisolon pulse therapy was not effective. Follow-up MRA displayed complete resolution of the stenosis of the MCA, PCA and BA.

Anti-N-Methyl-D-Aspartate Receptor-Related Grave but Reversible Encephalitis with Ovarian Teratoma in 2 Japanese Women Presenting with Excellent Recovery without Tumor Resection

ness and Kerning sign. Blood cell counts and routine serum biochemical analyses were normal. Serological testing for antinuclear and anti-DNA antibodies, tumor markers and syphilis were negative. Her cerebrospinal fluid (CSF) showed mild pleocytosis, was negative for tubercle bacilli on culture and for herpes simplex virus (HSV)-DNA on PCR. Brain MRI showed no abnormalities. The pelvic CT showed bilateral ovarian teratoma. EEG showed diffuse delta waves with no epileptic discharges. Intravenous administration of acyclovir was continued until the result of HSV-DNA on PCR was confirmed. Administration of methylprednisolone and antiepileptic drugs was started. However, her condition worsened gradually, and she presented with stereotypic oral dyskinetic movements. She fell in hypoventilation and coma, and was put on a ventilator. Her condition began to improve and ventilatory support was withdrawn on the 50th hospital day. She was discharged 83 days after hospitalization with excellent recovery. Antibodies to NR1/NR2B heteromers of NMDAR in the serum and CSF were positive on admission. One year after, the serum NMDAR antibodies were no longer detected. The pelvic MRI showed bilateral ovarian teratomas ( fig. 1 A), and the tumors did not change in size for 1 year. Acute encephalitis associated with ovarian teratoma preferentially affects young women and is characterized by acute prominent psychiatric symptoms, decreased level of consciousness, frequent seizures and central hypoventilation [1, 2] . Cases of reversible encephalitis affecting exclusively young women were reported in Japan under the name of ‘acute juvenile female non-herpetic encephalitis (AJFNHE)’ [3–5] . Dalmau et al. [6] recently reported that anti-N-methylD -aspartate receptor (NMDAR) antibody was positive in patients with acute encephalitis associated with ovarian teratoma as well as in mediastinum and grouped them in a category of NMDAR-related encephalitis. They recommended resection of the tumor for treatment [6–8] , but it is not always easy for young nulligravid women to have their ovaries removed. We report NMDAR-related encephalitis in 2 patients treated without tumor resection.

Neuropsychological Features of Microbleeds and Cortical Microinfarct Detected by High Resolution Magnetic Resonance Imaging

BACKGROUND Lobar microbleeds (MBs) and cortical microinfarct (CMI) are caused by cerebral amyloid angiopathy in the elderly and increase in number in Alzheimers disease. OBJECTIVE The aim of this study is to elucidate the effects of lobar MBs and CMIs on cognitive function. METHODS The subjects were outpatients who visited the memory clinic of Mie University Hospital. Among 120 subjects, 109 patients fulfilled the inclusion criteria. We quantitatively estimated MBs and CMIs using double inversion recovery and 3D FLAIR images of 3T MRI. Neuropsychological assessments included intellectual, memory, constructional, and frontal lobe function. RESULTS Of the 109 patients, MBs and CMIs were observed in 68 (62%) and 17 (16%) subjects, respectively. Of the 68 patients with MBs, lobar MBs were found in 28, deep MBs in 8 and mixed MBs in 31. In each age group, the number of MBs increased in patients with CMI (CMI+ group) than those without CMI (CMI- group), and MBs and CMIs additively decreased MMSE scores. In psychological screens, the MBs+ group with more than 10 MBs showed significantly lower scores of category- and letter-WF than MB- group. The CMI+ group showed significantly worse scores than CMI- group in Japanese Ravens coloured progressive matrices, Trail Making Test-A, category- and letter-word fluency and copy and drawing of figures. CONCLUSION Lobar MBs and CMIs in the elderly frequently coexisted with each other and additively contributed to cognitive impairment, which is mainly predisposed to frontal lobe function.

Cervical spinal cord infarction in a patient with cervical spondylosis triggered by straining during bowel movement

An 82-year-old man experienced sudden-onset left shoulder pain and hemiparesis, which subsided on the third day. MRI revealed an ischaemic lesion at the C3-4 level together with disk herniation and cord compression from C3/4 to C6/7. On the fourth day, however, similar symptoms recurred when straining during defecation, and then progressed in a fluctuating manner and finally resulted in quadriparesis and respiratory impairment. A follow-up MRI showed fresh infarction of the anterior spinal artery (ASA) territory extending from C2 to C5. Straining during defecation may have induced the second exacerbation by elevating the venous pressure in the craniospinal axis and intervertebral disc pressure and causing minor damage and intraluminal thrombus in the ASA.

Rheumatoid cranial pachymeningitis successfully treated with long-term corticosteroid.

We report a 68-year-old man without clinical history of rheumatoid arthritis who presented with acute bilateral palsy of the IX and X cranial nerves secondary to pachymeningitis confirmed on cranial MRI. Rheumatoid factor in both serum and cerebrospinal fluid and anti-agalactosyl IgG antibody in serum were positive. The radiographs of hands and feet revealed signs of early rheumatism. The dural biopsy specimen showed chronic inflammation with infiltration of lymphocytes and histiocytes. A diagnosis of rheumatoid cranial pachymeningitis was made. Treatment with long-term corticosteroid was excellently effective.

Low-signal-intensity rim on susceptibility-weighted imaging is not a specific finding to progressive multifocal leukoencephalopathy

BACKGROUND Low-signal-intensity (LSI) rim along deep layers of the cerebral cortex is reportedly a susceptibility-weighted imaging (SWI) finding in progressive multifocal leukoencephalopathy (PML). We aimed to evaluate whether this finding can be identified in diseases other than PML. METHODS We retrospectively reviewed brain MR images from 5605 patients who underwent SWI at 3T; 370 patients with various diseases, who showed cortical and subcortical FLAIR high-signal lesions including U-fiber, were enrolled. The presence or absence of LSI rim on thin-slice SWI and hyperintense cortical signal (HCS) on T1-weighted images adjacent to LSI rim was analyzed. Signal changes of the LSI rim were assessed on serial SWI, if available. RESULTS Twenty-five of the 370 patients (6.8%) showed SWI LSI rim, in infarct (n=22) and encephalitis (n=3). HCS was apparent adjacent to SWI LSI rim in 17 patients (15 infarct, 2 encephalitis). Serial SWI was available for 17 patients, of whom 10 patients (8 infarct, 2 encephalitis) presented LSI rim later than 45days after onset. CONCLUSION LSI rim can be observed in infarct and encephalitis. Therefore, this finding is not specific to PML. LSI rim appears to be associated with HCS.

A novel protein S gene mutation combined with protein S Tokushima mutation in a patient with superior sagittal sinus thrombosis

Thrombus formation is regulated by anticoagulatory and fibrinolytic systems on the vascular endothelial cells. Protein S (PS) plays an important role in blood coagulation, and its deficiency is a risk factor for cerebral venous thrombosis [1]. The frequency of Japanese deep vein thrombosis patients having mutated PS and/or protein C (PC) genes is higher than that reported for Caucasian patients [2]. We report a novel PS mutation combined with a PS-Tokushima mutation [3] in a patient with recurrent episodes. A 71-year-old woman with history of a superior mesenteric vein thrombosis that occurred 3 years prior to admission, had weakness in her left limbs and was admitted to a nearby hospital 1 day in November (first day). She took warfarin potassium for 3 years to prevent thrombosis, but she has not been regularly monitored by blood tests. The dose of warfarin potassium was increased at the hospital. She had neither a history of smoking nor a family history of thrombosis. She had sudden generalized convulsions on the fifth day and was transferred to our hospital. Her mouth was wet, and she had normal turgor skin with normal complete blood count and blood chemistries. Her BMI (body mass index) was 20.4. We ruled out dehydration by physical and blood exam. A screening for thrombophilia identified a reduced PS activity (18%) and antigen level (45%) (Table 1). Brain magnetic resonance (MR) imaging revealed high intensity in the right frontal lobe on T2weighted and fluid-attenuated inversion recovery (FLAIR) images, and MR venography failed to reveal superior sagittal sinus clearly (Fig. 1). Further cerebral angiography revealed superior sagittal sinus thrombosis. She was able to walk back home 1 month after. The PS gene was investigated, and the nucleotide sequence analysis of all amplified exons and intron–exon boundaries of the PS gene revealed two separate mutations, including one novel point mutation (Gly148Ala), and the other a previously identified missense mutation (Lys155Glu, PS-Tokushima) [3]. These two mutations are present in separate allele. This patient had recurrent venous thromboembolism (VTE). Cerebral venous sinus thrombosis exhibits such a

Comparative Analysis of Cortical Microinfarcts and Microbleeds using 3.0-Tesla Postmortem Magnetic Resonance Images and Histopathology

Microvascular lesions including cortical microinfarctions (CMIs) and cerebral lobar microbleeds (CMBs) are usually caused by cerebral amyloid angiopathy (CAA) in the elderly and are correlated with cognitive decline. However, their radiological-histopathological coincidence has not been revealed systematically with widely used 3-Tesla (3T) magnetic resonance imaging (MRI). The purpose of the present study is to delineate the histopathological background corresponding to MR images of these lesions. We examined formalin-fixed 10-mm thick coronal brain blocks from 10 CAA patients (five were also diagnosed with Alzheimer’s disease, three with dementia with Lewy bodies, and two with CAA only) with dementia and six non CAA patients with neurodegenerative disease. Using 3T MRI, both 3D-fluid attenuated inversion recovery (FLAIR) and 3D-double inversion recovery (DIR) were examined to identify CMIs, and T2* and susceptibility-weighted images (SWI) were examined to identify CMBs. These blocks were subsequently examined histologically and immunohistochemically. In CAA patients, 48 CMIs and 6 lobar CMBs were invariably observed in close proximity to degenerated Aβ-positive blood vessels. Moreover, 16 CMIs (33%) of 48 were detected with postmortem MRI, but none were seen when the lesion size was smaller than 1 mm. In contrast, only 1 undeniable CMI was founded with MRI and histopathology in 6 non CAA patients. Small, cortical high-intensity lesions seen on 3D-FLAIR and 3D-DIR images likely represent CMIs, and low-intensity lesions in T2* and SWI correspond to CMBs with in vivo MRI. Furthermore, a close association between amyloid-laden vessels and these microvascular lesions indicated the contribution of CAA to their pathogenesis.

Bilateral abducens nerve palsy by compression from bilateral anterior inferior cerebellar artery

Isolated abducens nerve palsy affects patients with various pathological conditions, including head trauma, brain tumor, and infection. Systemic conditions such as diabetes mellitus or hypertension are also risk factors for abducens nerve palsy and may cause ischemic neuropathy [1]. Furthermore, compression by vascular abnormalities such as dolichoectatic arteries or aneurysms may induce abducens nerve palsy at its long extracerebral segment [2–7]. However, bilateral cases of isolated abducens nerve palsy are rare. Such cases have been reported in patients with ruptured aneurysms of the anterior communicating [8] or vertebrobasilar artery [9, 10], bilateral intracavernous carotid artery aneurysms [7], or subarachnoid hemorrhage without aneurysm [9]. Here, we report a case of bilateral isolated abducens nerve palsy due to compression by the bilateral anterior inferior cerebellar artery (AICA). A 75-year-old man developed diplopia without ocular pain 6 months earlier. He had undergone surgeries for gastric ulcer 33 years earlier and lung adenocarcinoma 9 years earlier. Follow-up for lung cancer revealed no evidence of relapse or metastasis. Two months earlier, diplopia worsened without other symptoms. Neurological examination revealed left ptosis, which had previously been identified. Additionally, there was complete right, and moderate left, abducens nerve palsy, but no abnormalities in pupil size, light reflex, and vertical eye movement (Fig. 1a). Laboratory tests showed slightly elevated glycosylated hemoglobin Alc level (6.6%; normal range: 4.3–5.8%), but normal erythrocyte sedimentation rate and thyroid function. Anti-acetylcholine esterase antibody and edrophonium tests were negative. Cerebrospinal fluid analysis showed a mild increase in protein content (50 mg/dL) and normal cell count (1 lymphocyte/lL) without malignant cells. Positron emission tomography/computed tomography scan revealed no abnormalities. Brain magnetic resonance (MR) imaging, including with gadolinium enhancement, showed no brainstem or cavernous sinus lesions. MR angiography demonstrated dolichoectatic basilar and left vertebral arteries (Fig. 1b). MR 3D heavy T2-weighted imaging showed stretching of the right abducens nerve by the right AICA (Fig. 1c) and compression of the left abducens nerve at the point of its exit zone by the left AICA (Fig. 1d). The condition improved slightly over 4 months, and there was no evidence of focal or systemic recurrence of lung cancer at 25 months after the onset of diplopia. An anatomical study showed that the ventral surface of the abducens nerve was crossed by the AICA in 75% of autopsied brains and that, in the majority of cases, the AICA was in contact with the abducens nerve [11]. Another study showed the AICAs or their branches were in contact with it in all cases of 44 hemispheres, and pierced in 11.4% [12]. In this patient, the left vertebral artery and basilar arteries were dolichoectatic with a deviation to the right, and the bilateral abducens nerves were compressed by the A. Taniguchi (&) Y. Ii H. Tomimoto Department of Neurology, Mie University Graduate School of Medicine, Edobashi 2-174, Tsu, Mie 514-8507, Japan e-mail: a2005t@clin.medic.mie-u.ac.jp