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Parkinson’s disease (PD) is caused by a combination of genetic and environmental factors. Notably, genetic risk factors vary according to ethnicity and geographical regions, and few studies have analyzed the frequency of PD causative genes in Japanese patients. Therefore, we performed genetic analyses of Japanese patients with PD. We recruited 221 participants, including 26 patients with familial PD. Genetic risk factors were evaluated by target sequencing and gene dosage analysis. We detected the genetic risk factors in 58 cases (26.2%) and classified patients into three groups to clarify the differences in genetic risk factors by age at onset (AAO). The early-onset group (AAO

Spinocerebellar ataxia (SCA) is a genetically heterogeneous disease characterized by cerebellar ataxia. Many causative genes have been identified to date, the most common etiology being the abnormal expansion of repeat sequences, and the mutation of ion channel genes also play an important role in the development of SCA. Some of them encode calcium and potassium channels. However, due to limited reports about potassium genes in SCA, we screened 192 Japanese individuals with dominantly inherited SCA who had no abnormal repeat expansions of causative genes for potassium channel mutations (KCNC3 for SCA13 and KCND3 for SCA19/SCA22) by target sequencing. As a result, two variants were identified from two patients: c.1973G>A, p.R658Q and c.1018G>A, p.V340M for KCNC3, and no pathogenic variant was identified for KCND3. The newly identified p.V340M exists in the extracellular domain, and p.R658Q exists in the intracellular domain on the C-terminal side, although most of the reported KCNC3 mutations are present at the transmembrane site. Adult-onset and slowly progressive cerebellar ataxia are the main clinical features of SCA13 and SCA19 caused by potassium channel mutations, which was similar in our cases. SCA13 caused by KCNC3 mutations may present with deep sensory loss and cognitive impairment in addition to cerebellar ataxia. In this study, mild deep sensory loss was observed in one case. SCA caused by potassium channel gene mutations is extremely rare, and more cases should be accumulated in the future to elucidate its pathogenesis due to channel dysfunction.

Background The etiology of transient global amnesia (TGA) remains unclear. We studied the pathophysiology of TGA in 165 Japanese patients. Subjects and Methods TGA was diagnosed in hospitalized patients from 2004 to 2015. We analyzed clinical characteristics, magnetic resonance imaging findings, and maximum intima-media thickness of the common carotid artery, and the reflux of internal jugular venous (IJV) flow by ultrasonography, and statistically compared patients with TGA with age-matched and sex-matched patients who have had a transient ischemic attack (TIA), small-vessel occlusion (SVO), and normal controls (each group, N = 165). Results Patients with TGA showed lower prevalence of vascular risk factors than patients with TIA and SVO did. Eleven patients (6.7%) had 2 episodes of TAG, but specific clinical variables could not be recognized in these patients. The maximum intima-media thickness was significantly thinner in TGA (1.1 ± .7 mm) than in SVO (1.6 ± .9 mm; P = .001). The percentages of cases whose IJV flow reflux was increased by Valsalva maneuver showed no difference ( P = .573) between TGA (26.0 %) and SVO (29.4%). MR diffusion-weighted imaging yielded small hyperintense signals in the hippocampus in 64 of 90 (71.1%) patients between 24 and 72 hours. Potential precipitating specific factors or events before the attacks could be recognized in 40 cases (24.2%) of 165 patients. Conclusion Arterial ischemia and IJV flow reflux might not contribute to TGA pathophysiology. The vulnerability of the hippocampus to physical or emotional stress might be suspected as an underlying mechanism in some patients with TGA.

A 64-year-old woman was admitted to our hospital owing to decreased visual acuity and visual field defect. She had a similar history of decreased visual acuity and received steroid therapy 10 years ago. Brain MRI revealed gadolinium-enhancement in the sheath of the optic nerve, called "tram-track" and "doughnut" signs. Optic perineuritis (OPN) was diagnosed on the basis of her clinical manifestations, which improved on treatment with high-dose methylprednisolone (mPSL). However, clinical manifestations relapsed 10 days post-discharge; hence, she was re-admitted. She was re-administered high-dose mPSL and subsequent oral administration of prednisolone. She had no relapse or recurrence for the last 2 years. We reviewed studies involving Japanese patients with OPN, including 17 idiopathic and 14 secondary cases and found that 43% of patients had recurrences and 30% of patients had poor outcome including severe residuals of visual acuity. Secondary OPN occurred owing to various diseases manifesting generalized systematic inflammation. Timely and suitable treatment was very important for clinical favorable outcomes in OPN.

Spinocerebellar ataxia (SCA) is a genetically heterogeneous disease characterized by cerebellar ataxia. Many causative genes have been identified to date, the most common etiology being the abnormal expansion of repeat sequences, and the mutation of ion channel genes also play an important role in the development of SCA. Some of them encode calcium and potassium channels. However, due to limited reports about potassium genes in SCA, we screened 192 Japanese individuals with dominantly inherited SCA who had no abnormal repeat expansions of causative genes for potassium channel mutations (KCNC3 for SCA13 and KCND3 for SCA19/SCA22) by target sequencing. As a result, two variants were identified from two patients: c.1973GA, p.R658Q and c.1018GA, p.V340M for KCNC3, and no pathogenic variant was identified for KCND3. The newly identified p.V340M exists in the extracellular domain, and p.R658Q exists in the intracellular domain on the C-terminal side, although most of the reported KCNC3 mutations are present at the transmembrane site. Adult-onset and slowly progressive cerebellar ataxia are the main clinical features of SCA13 and SCA19 caused by potassium channel mutations, which was similar in our cases. SCA13 caused by KCNC3 mutations may present with deep sensory loss and cognitive impairment in addition to cerebellar ataxia. In this study, mild deep sensory loss was observed in one case. SCA caused by potassium channel gene mutations is extremely rare, and more cases should be accumulated in the future to elucidate its pathogenesis due to channel dysfunction.

BackgroundTheTWNKgene encodes the twinkle protein, which is a mitochondrial helicase for DNA replication. The dominantTWNKvariants cause progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 3, while the recessive variants cause mitochondrial DNA depletion syndrome 7 and Perrault syndrome 5. Perrault syndrome is characterized by sensorineural hearing loss in both males and females and gonadal dysfunction in females. Patients with Perrault syndrome may present early-onset cerebellar ataxia, whereas middle-age-onset cerebellar ataxia caused byTWNKvariants is rare.Case presentationA Japanese female born to consanguineous parents presented hearing loss at age 48, a staggering gait at age 53, and numbness in her distal extremities at age 57. Neurological examination revealed sensorineural hearing loss, cerebellar ataxia, decreased deep tendon reflexes, and sensory disturbance in the distal extremities. Laboratory tests showed no abnormal findings other than a moderate elevation of pyruvate concentration levels. Brain magnetic resonance imaging revealed mild cerebellar atrophy. Using exome sequencing, we identified a homozygousTWNKvariant (NM_021830: c.1358G>A, p.R453Q).ConclusionsTWNKvariants could cause middle-age-onset cerebellar ataxia. Screening forTWNKvariants should be considered in cases of cerebellar ataxia associated with deafness and/or peripheral neuropathy, even if the onset is not early.

Background Few studies have examined the prevalence of peripheral arterial disease (PAD) with the use of computed tomography angiography (CTA) in patients with acute ischemic stroke (AIS), although several reports have examined its prevalence using an ankle brachial index (ABI). We aimed to determine the prevalence of PAD indicated by CTA in patients with AIS and to clarify the prevalence of PAD in each clinical ischemic stroke subtype. Methods We included 199 consecutive patients with AIS admitted to our hospital and divided them into PAD and non-PAD groups according to the CTA findings. Results Of the 199 patients, 40 (20.1%) had PAD; 27 (67.5%) of the PAD patients were asymptomatic. The prevalence of abnormal ABI (≤.9) was 12.2%. Patients with PAD were older (78.3 ± 10.2 versus 71.5 ± 10.9, P .001) and had a significantly lower ABI value (.89 ± .24 versus 1.15 ± .09, P .001) and higher prevalence of diabetes mellitus (50.0% versus 31.4%, P = .028), atrial fibrillation (40.0% versus 16.4%, P = .001), coronary artery disease (32.5% versus 8.2%, P .001), and intracranial arterial stenosis (47.5% versus 28.9%, P = .025) than patients without PAD. The prevalence of cerebral microbleeds was not different between patients with PAD and those without PAD (25.6% versus 25.4%, P = .985). The prevalence of PAD among ischemic stroke subtypes was highest in patients with cardioembolic infarction (40.5%). Conclusions Almost one fourth of the AIS patients examined had PAD on CTA. Cardioembolic infarction patients showed the highest prevalence of PAD among the clinical ischemic subtypes, suggesting the coexistence of atheromatous diseases and atrial fibrillation.

We report the case of a 25-year-old man with multiple sclerosis (MS) who had severe headache and unconsciousness. He suffered from optic neuritis that had started at age 6. From the age of 12 years, he had suffered from multiple sclerosis (MS) cerebral lesions that relapsed three times over for 5 years. At age 25, he showed a new lesion in the cerebellar cortex, suggesting an exacerbation of the MS. However, magnetic resonance imaging findings the next day showed cerebral venous sinus thrombosis. His laboratory findings showed low antithrombin activity. Genetic analysis revealed a single-base substitution (C>T) at the codon 359 (Arg to STOP) in the 5th exon portion of the antithrombin gene, heterozygote. In the literature review, 17 cases of multiple sclerosis associated with cerebral venous sinus thrombosis, which occurred after the lumbar puncture and the treatment with high-dose methylpredonisolone in 11 of these cases. In our case, antithrombin deficiency, hyperhomocystinemia, infection, and lumbar puncture were suggested as the risk factors.

We report the patient of a 53-year-old woman who developed subacute-onset marked tonge protrusion and bite. She was diagnosed as dementia with Lewy bodies (DLB) from the clinical features including progressive cognitive decline, visual hallucinations, parkinsonism, and severe insomnia and depression, and the radiological finding of low dopamine transported uptake in basal ganglia by Dat SCAN and low blood circulation in occipital lobe of cerebrum. The patient received 600 mg doses of levodopa for over a year, followed by rotigotine and ropinirole with a rapid increase of dosage. It is believed that these treatments stimulated and sensitized dopamine D1 receptors, thereby inducing lingual dystonia. Furthermore, the patient demonstrated dyspnea and attacks of apnea caused by the closure of bilateral vocal cords due to laryngeal dyskinesia. After initiation of the neuroleptic, olanzapine, for a short duration, the high dose of levodopa overlapped with neuroleptic sensitivity, suggesting DOPA-induced dystonia and dyskinesia. This interaction can sometimes lead to lethal adverse events, and must be considered very important when treating patients with DLB.

ObjectiveTo determine the genetic underpinnings of slowly progressive spinocerebellar ataxia, autosomal recessive (SCAR), we performed exome analysis and examined the relationship between clinical severity and functional change induced by the mutation.MethodsHomozygosity fingerprinting and exome sequencing were performed to identify causative mutations in 2 consanguineous families. We assessed the expression of D-bifunctional protein (DBP) and the amount of dimerized DBP in fibroblasts by immunoblot and quantitative reverse transcription PCR. The pathogenicity of the mutation was evaluated using the Combined Annotation-Dependent Depletion (CADD) scores; these results were compared with the scores of previously reported mutations.ResultsWe identified a homozygous mutation as causative of middle age–onset SCAR: p.Ala175Thr, which is located in HSD17B4 that encodes peroxisomal DBP. The patients developed cerebellar ataxia, and the subsequent progression was slow. The symptoms presented were milder than those in previously reported cases. The messenger RNA expression levels were normal, but protein levels were diminished. Dimerization of DBP was also reduced. The CADD score of the identified mutation was lower than those of previously reported mutations.ConclusionsThis is the report of middle age–onset DBP deficiency. Residual functional DBP caused relatively mild symptoms in the affected patients, i.e., slowly progressive ataxia and hearing loss. This study broadens the scope of DBP deficiency phenotypes and indicates that CADD scores may be used to estimate the severity of DBP deficiencies.

We experienced 13 cases (29.8 ± 7.0 years) of mumps meningitis and 365 cases of adult aseptic meningitis during 11 years from 2004 to 2014. A small epidemic of mumps occurred for 3-4 years, and the incidence rate of adult mumps meningitis coincided with the epidemic without seasonal fluctuation. Parotitis was observed in 8 of the 13 mumps meningitis patients (61.5%) and orchitis in 2 of 7 male patients (28.6%). There were no differences in clinical manifestations, laboratory findings, and outcome between patients with adult mumps meningitis and those with echovirus 9 meningitis (9 patients), except for the low frequency of nausea/vomiting and a high percentage of mononuclear cells of the cerebrospinal fluid in those with mumps. Eight patients had contact with persons with mumps before the symptomatic stage of meningitis. Only one patient had received mumps vaccination in childhood. On the basis of the values of the anti-mumps IgM and IgG antibodies, we speculated primary infection and the re-infection of mumps in 6 and 2 patients, respectively. Moreover, second vaccine failure was suggested in the vaccinated patient.

A 45-year-old right-handed man with a past history (10 years) of putaminal hemorrage presented with auditory agnosia associated with left putaminal hemorrhage. It was suspected that the auditory agnosia was due to bilateral damage in the acoustic radiations. Generalized auditory agnosia, verbal and non-verbal (music and environmental), was diagnosed by neuropsychological examinations. It improved 4 months after the onset. However, the clinical assessment of attention remained poor. The cognition for speech sounds improved slowly, but once it started to improve, the progress of improvement was rapid. Subsequently, the cognition for music sounds also improved, while the recovery of the cognition for environmental sounds remained delayed. There was a dissociation in recovery between these cognitions. He was able to return to work a year after the onset. We also reviewed the literature for cases with auditory agnosia and discuss their course of recovery in this report.

A 63-year-old man noticed hypogeusia after presenting hiccups for several days. He was serologically diagnosed with varicella-zoster virus (VZV) infection, but had no skin lesions typical of herpes (zoster sine herpete). Hypogeusia was confirmed by electrogustometry and the filter-paper disk method, which showed damage in the areas innervated by the cord of tympanum, glossopharyngeal nerve, and greater petrosal nerve. High signals in the nuclei of the solitary tract of the medulla oblongata and the enhancement of the bilateral intracranial segments of the cranial nerve IX and X complex were observed by magnetic resonance imaging (MRI). The signal changes in the nuclei of the solitary tract on MRI were seen for more than 2 months, and hypogeusia lasted for more than 7 months. Hypogeusia caused by VZV infection has rarely been reported; however, similar cases could have gone undiagnosed or underdiagnosed in patients with idiopathic hypogeusia. (Received August 18, 2016; Accepted September 29, 2016; Published February 1, 2017).

Background: Serum 1,5-anhydroglucitol (1,5-AG) levels are a measure that provides information on daily glycemic variations. We evaluated whether 1,5-AG could be a possible marker of acute ischemic stroke (AIS) or transient ischemic attacks (TIA) in patients with diabetes mellitus (DM). Methods: We retrospectively reviewed electronic medical records of 5,294 AIS/TIA patients. Of the 5,294, 1,898 had diabetes and in 1,246, serum 1,5-AG levels were measured (group S). Group S was divided into 2 subgroups: hemoglobin A1c (HbA1c) 7% (S-high). As controls, 394 outpatients with diabetes (group C) without AIS/TIA were likewise divided into subgroups, C-low and C-high according to HbA1c level. In each HbA1c subgroup, the association between serum 1,5-AG (≥14 vs. Results: Overall, serum 1,5-AG levels were lower in group S than in group C. Serum 1,5-AG levels were low in subgroups S-high and C-high, showing no differences in mean values. However, mean serum 1,5-AG levels in S-low was statistically lower than that in C-low. MLR analysis showed that the OR for low (Conclusions: Low serum 1,5-AG levels could be a possible marker for AIS/TIA risk in patients with well-controlled DM.

Background: Cerebral venous sinus thrombosis (CVT) occurs commonly in young female adults and is caused by various risk factors. Our aim was to determine the incidence, clinical characteristics, and risk factors of Japanese CVT patients. Patients and methods: We performed a retrospective study of CVT patients from January 2010 to June 2015. In the patients who had hyperhomocysteinemia, vitamin levels were measured. To define the clinical characteristics in patients with hyperhomocysteinemia, we statistically compared them to those patients with normal levels of homocysteine. Results: Sixteen patients (aged 54.6 ± 17.7 years; 13 men and 3 women) were included. The incidence of CVT was 0.23% among all types of strokes or 0.30% of acute ischemic strokes, which was lower than previously reported. The patients were characterized by advanced age, low frequency of headaches, and few female patients, especially female patients using oral contraceptives. The predisposing conditions included a notably high incidence of hyperhomocysteinemia (56.3%). They also included deficiencies of folate, vitamin B12, vitamin B6, or combined deficiencies. Marked hyperhomocysteinemia over 100 nmol/ml was noted in combined deficiencies. Conclusions: CVT in Japan commonly occurred in older males. The prevalence of hyperhomocysteinemia as a risk factor of CVT was high, and the main underlying disorders were folate and vitamin B12 or B6 deficiencies. This is clinically important, because these acquired risks can be corrected by supplementation therapy to prevent the recurrence of CVT.

We herein report two cases of acute ischemic stroke associated with iron deficiency anemia (IDA) due to bleeding from uterine fibroids. Anemia is not generally recognized as a risk factor for stroke. The physiological mechanisms that may factor in the development of ischemic stroke in patients with IDA include thrombocytosis, hypercoagulable state, and anemic hypoxia. In our two cases, IDA was considered to be the cause of ischemic stroke because all other known causes of stroke were ruled out. In patients with ischemic stroke due to anemia, early treatment of the anemia is important to prevent stroke recurrence.

We report a case of a 55-year-old man who developed acute-onset narrowing of his visual field. He showed right homonymous hemianopsia without any other neurological symptoms and signs. Brain CT and MRI showed localized hemorrhage (about 1.6 ml) in the left lateral geniculate body (LGB). A cerebral angiography showed no vascular anomalies of cerebral vessels, and the left anterior choroidal artery and left lateral posterior choroidal artery could be visualized well. He had hypertension, polycythemia and dyslipidemia and was a habitual smoker and an alcoholic. In the literature, various kinds of visual field defects including hemianopsia, upper quadrant hemianopsia, lower quadrant hemianopsia, and horizontal sectoranopia have been reported in eight cases of LGB hemorrhage. Localized LGB hemorrhage was found in only one case out of 2,763 cerebral hemorrhage patients enrolled in our stroke registry for 11 years from 2005 to 2016. Localized hemorrhage of LGB very rarely occurred.

Introduction: Current guidelines set the goal of diabetes control to a glycated hemoglobin A1c (HbA1c) level of Hypothesis: 1,5AG can be used to evaluate the risk of CI in patients with well-controlled diabetes. Methods: We retrospectively reviewed the medical records of 1169 patients with diabetes who received treatment for CI at our hospital between 2009 and 2014. These patients were divided into the following two groups according to their HbA1c-based diabetes control status: a CI-low group (HbA1c Results: There was no difference in the 1,5AG level between the CI-high and nonCI-high groups (8.8±7.3% vs. 8.9±7.1%, p=0.83). However, the 1,5AG level was significantly lower in the CI-low group than in the nonCI-low group (12.5±8.1% vs. 15.2±8.8%, p Conclusion: The results of this study show that short-term glycemic control and glycemic variability have a significant relationship with existing CI especially in patients with good diabetes control. The 1,5AG level may be a surrogate measure of the risk of CI in patients with HbA1c levels that indicate good diabetes control.

Introduction: Cerebral microbleeds (CMBs) are considered as a risk factor for stroke. The incidence of post-tPA microbleeds have been reported in recent studies, however, it is not clear that whether hybrid procedure (the combination of tPA and endovascular thrombectomy) for ischemic stroke would increase risk of post-treatment CMBs more than treatment with tPA or endovascular thrombectomy alone. Objective of this study is to compare the incidence of post-treatment CMBs and symptomatic exraischemic hemorrhage by treatments: hybrid procedure, tPA alone, and endovascular thrombectomy alone. Hypothesis: Combined therapy of endovascular thrombectomy and tPA for ischemic stroke have higher incidence of post-treatment CMBs than tPA or endovascular thrombectomy alone. Methods: We retrospectively reviewed pre- and post-T2*-weighted MRI of ischemic stroke patients who received above treatments in our hospital during 2010 to 2014. The presence and number of CMBs were assessed according to the Brain Observer Microbleeds Scale. We compared the number of pre-treatment CMBs, incidence of newly-occurred post-treatment CMBs and symptomatic extraischemic hemorrhage within a year after treatments among hybrid procedure, tPA alone, and endovascular thrombectomy alone. Results: A total of 147 (hybrid procedure n=17, tPA alone n=90, endovascular thrombectomy alone n=40) patients’ pre- and post-treatment MRIs were reviewed. The average number of pre- treatment CMBs was 1.4±4.0 and there was no difference among treatments. The incidence of post-treatment CMBs was significantly higher in hybrid procedure (n=5, 29.4%) and tPA alone (n=18, 20.0%) than endovascular thrombectomy (n=1, 2.5%). However, there was no difference between hybrid procedure and tPA alone. Symptomatic extraischemic hemorrhage was found only one patient who received endovascular thrombectomy alone. Conclusion: The incidence of CMBs after treatments was increased in treatments using tPA. However, there was no difference in post-treatment incidence between hybrid procedure and tPA alone. This result suggests that additional thrombectomy after tPA would not increase the risk of CMBs.

A 63-year-old man was admitted to our hospital because of convulsive seizures. Radiological examinations revealed cerebral venous sinus thrombosis in the anterior part of the superior sagittal sinus. He had marked hyperhomocysteinemia (93.5 nmol/ml) due to combined deficiencies of folate and vitamin B12. He was T/T homozygous for methylene tetrahydrofolate reductase C677T polymorphism. He received a supplement therapy of vitamins. First, he was administered folate orally. After 3 months, the serum level of homocysteine decreased to 22.6 nmol/ml (an 86% reduction), but was still above the normal level. Next, an additional supplement therapy of vitamin B12 lowered the homocysteine level to normal (12.3 nmol/ml) after 4 months. These results showed that the increase of homocysteine levels in this patient was mainly caused by the deficiency of folate. Additionally, acquired risk factors like vitamin deficiencies increased the level of serum homocysteine to almost 100 nmol/ml.

It is important to determine the usage of anticoagulants by defining the actual risk of cardioembolic stroke in patients with old myocardial infarction. In the present study, we aimed to more precisely evaluate the risks of each segment associated with cardioembolic stroke using a 16-segment model. The usage of the plasma brain natriuretic peptide (BNP) associated with cardioembolic stroke was also evaluated in comparison with a left ventricle ejection fraction less than 40%.There were a total of 190 ischemic stroke patients who had premorbid myocardial infarction. The study included a total of 143 ischemic stroke patients with old myocardial infarction who were available for evaluation and excluded patients with atrial fibrillation or acute myocardial infarction. Their left ventricle wall motion abnormality and the level of plasma BNP at their admission were analyzed.Hypertension and a plasma BNP level of 206.9 pg/mL or higher, determined from the receiver operating characteristic curve, were independently associated with cardioembolic stroke (χ(2) = 35.6, R(2) = .30, P .001). Adjusting for these factors, statistically independent high risk was observed at the basal-inferior, basal-inferolateral, mid-anterior, mid-anteroseptal, apical-anterior, and apical-septal left ventricles.High plasma BNP levels and left ventricular wall motion abnormalities in the segments perfused with left anterior descending coronary artery or right coronary artery show a high risk for cardioembolic stroke in patients with old myocardial infarction. Considering these factors, it could be possible to more precisely define the risk of cardioembolic stroke and to perform appropriate antithrombotic treatments in old myocardial infarction patients.

We report the case of a 73-year-old woman presenting with hypersomnia and loss of appetite. She suffered from diabetic nephropathy without receiving dialysis, in addition to hypertension, which was well controlled without marked fluctuation. There were no objective neurological findings. Her laboratory findings showed renal failure with 3.7 mg/dl of serum creatinine and decreased serum sodium and potassium. Brain magnetic resonance imaging (MRI) showed posterior reversible encephalopathy syndrome (PRES) with vasogenic edema, which was distributed in the dorsal midbrain, medial thalamus, and hypothalamus. After we addressed the electrolyte imbalance and dehydration, her symptoms and MRI findings gradually improved, but faint high signals on MRI were still present 3 months later. Orexin in the cerebrospinal fluid was decreased on admission, but improved 6 months later. We diagnosed uremic encephalopathy with atypical form PRES showing functional disturbance of the hypothalamus.

A 66-year-old woman was diagnosed with a brain abscess. The abscess was drained by sterotactic catheter insertion. She was administered metronidazole at a dose of 2 g/day. On the 30th day of treatment, she had nausea that gradually progressed. On the 45th day, she developed a disturbance of consciousness and was admitted to our department. She was in stuporous state, and had slight vestibular and cerebellar dysfunctions. Diffusion-weighted and FLAIR brain MR images showed bilateral symmetrical high signals in the splenium of the corpus callosum (SCC), cerebellar dentate nucleus, and inferior colliculus. The apparent diffusion coefficient (ADC) map was reduced in the SCC, but not in the other locations. The peak of lactate on MR spectroscopy was increased in the SCC. The clinical presentation and image changes of the patient were thought to be most consistent with metronidazole toxicity. Metronidazole was discontinued, and her condition improved rapidly. She was discharged 14 days later. The lesions in her cerebellar dentate nucleus and inferior colliculus, suspected to be vasogenic edema, had disappeared 5 to 10 days later, whereas the lesion in the SCC, which gradually diminishing, could still be faintly detected 40 days later, which corresponded to our suspicion of cytotoxic edema.