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This study aimed to test our hypothesis that the cerebellum plays an important role in the generation of the optical-geometric illusion known as the Poggendorff illusion, the mechanism of which has been explained by accumulated experience with natural scene geometry. A total of 79 participants, comprising 28 patients with isolated cerebellar stroke, 27 patients with isolated cerebral stroke and 24 healthy controls, performed Poggendorff illusion tasks and 2 different control tasks. We also investigated core brain regions underpinning changes in the experience of the illusion effect using multivariate lesion-symptom mapping. Our results indicate that patients with isolated cerebellar stroke were significantly less likely to experience the Poggendorff illusion effect than patients with isolated cerebral stroke or healthy controls (74.6, 90.5 and 89.8%, respectively; F(2,76) = 6.675, P = 0.002). However, there were no inter-group differences in the control tasks. Lesion-symptom mapping analysis revealed that the brain lesions associated with the reduced frequency of the Poggendorff illusion effect were mainly centred on the right posteromedial cerebellar region, including the right lobules VI, VII, VIII, IX and Crus II. Our findings demonstrated, for the first time, that patients with cerebellar damage were significantly less likely to experience the Poggendorff illusion effect and that right posteromedial cerebellar lesions played an important role in this effect. These results provide new insight into alterations of a geometric illusion effect in patients with cerebellar disorders and pave the way for future clinical use of the illusion task to detect cerebellar abnormalities.

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are common treatments for ischemic stroke prevention in patients with carotid artery stenosis. However, the beneficial effects of CEA/CAS for cerebral hypoperfusion due to carotid artery stenosis have yet to be fully established. As dizziness is a common symptom in patients with carotid artery stenosis, we aimed to evaluate the effects of CEA/CAS on cerebral function in patients with carotid artery stenosis, using equilibrium function tests.This prospective observational cohort study included 50 patients who had carotid artery stenosis and were scheduled to undergo CEA or CAS. Before CEA/CAS, we quantitatively evaluated the vestibulo-ocular reflex (VOR) and vestibular evoked myogenic potential (VEMP), as indicators of brainstem/inner ear functions related to balance, and visual suppression of VOR, as an indicator of cerebral control over the brainstem reflex related to balance. These were then compared with supratentorial cerebral blood flow (CBF). Changes in VOR, VEMP, visual suppression of VOR, CBF, and dizziness after CEA/CAS were also evaluated.The visual suppression rates of VOR correlated with supratentorial CBFs before CEA/CAS (correlation coefficient = 0.47, p = 0.003). The visual suppression rates of VOR (p 0.001) and supratentorial CBFs (p = 0.003) were improved by CEA/CAS, while VOR and VEMP did not change. Symptoms of dizziness improved after CEA/CAS.Our results suggest that visual suppression of the VOR may be a novel and practical marker for the beneficial effects of CEA/CAS on supratentorial cerebral function.

Pathophysiology of vertigo/dizziness can be understood by eye deviation (nystagmus). In benign paroxysmal positional vertigo, eye deviation of causative semicircular canal stimulation is directly observed. In other peripheral vestibular disorders, eye deviation results from the sum of unilateral all semicircular canal disorders. The central vestibular pathway is controlled by the cerebellum. Thus, in vertigo/dizziness of central origin, not only eye deviation due to impairment of the central vestibular pathway but also deviation due to disinhibition of the pathway from the cerebellum is observed. The cerebellar control on the central vestibular pathway also plays an important role in vestibular compensation. When treating vertigo/dizziness, it is necessary to understand the pathophysiology of the vertigo/dizziness, to set the treatment target based on the pathophysiology, and to intervene for the target.

Characteristics of vestibular evoked myogenic potentials (VEMPs) depend on stimulus conditions.To determine the optimal stimulus conditions for cervical and ocular VEMPs.Participants were 23 healthy subjects. We compared air-conducted cervical and ocular VEMPs elicited by various tone-burst conditions (frequencies 500-1,000 Hz, rise/fall times 1-2 ms, and plateau times 0-6 ms) with an intensity of 105 dB normal hearing level. Effects of simultaneous contralateral masking noise on VEMPs were also evaluated.The largest cervical VEMP amplitudes were elicited by 500-750 Hz and 2-6 ms plateau time-tone-bursts, and the largest ocular VEMP amplitudes by 750 Hz and 2-4 ms plateau time-tone-bursts. Repeatability of the latency was better at 1 ms than at 2 ms rise/fall time in both VEMPs. In both VEMPs, masking noise reduced amplitude, and in ocular VEMP, amplitudes were significantly larger at the left ear stimulation than the right.Optimal tone-burst stimulation for both VEMPs seemed to be 500-750 Hz frequency and 1/2/1 ms rise/plateau/fall time without contralateral masking noise. Ocular VEMP amplitudes from left ear stimulation were originally larger than those from right ear stimulation.

Light transmission aggregometry is a standard method used to evaluate platelet function. However, in clinical settings, light transmission aggregometry results sometimes fail to reflect actual platelet hyperactivity. In patients with suspected platelet hyperactivity such as thrombosis, platelet aggregates are frequently detected in citrated blood samples using a scattergram of a hematology analyzer. This study aimed to evaluate the effects of platelet aggregate formation on light transmission aggregometry results.We used 19 citrated blood samples in which platelet aggregate formation was intentionally induced by a hematology analysis process. Employing fully automated light transmission aggregometry and agonists including adenosine diphosphate or collagen, light transmission aggregometry maximum aggregation percentage, platelet count, and mean platelet volume of platelet-rich plasma before and after platelet aggregate formation were evaluated.Light transmission aggregometry maximum aggregation percentage with adenosine diphosphate or collagen was significantly lower in the samples after than before platelet aggregate formation. Platelet count and mean platelet volume were both decreased by platelet aggregate formation (P.01), suggesting that maximum aggregation percentage reduction was caused by the decrease in activated large platelets in the platelet-rich plasma.This study clarified that platelet aggregate formation in blood samples interfered with an accurate assessment of platelet hyperactivity. To ensure reliability of light transmission aggregometry results, we must confirm that platelet aggregates have not formed in the sample, especially in those of patients with platelet hyperactivity.

Background and purpose Lateral medullary infarction (LMI) sometimes causes long-lasting dizziness. Although the precise mechanism of chronic post-LMI dizziness is unknown, a cerebellar control disorder of the vestibulo-ocular reflex (VOR) has been reported in such patients. We conducted a proof-of-principle cohort study to assess the potential efficacy of cerebellar repetitive transcranial magnetic stimulation (rTMS) as treatment for chronic post-LMI dizziness. Methods We first applied cerebellar rTMS in healthy volunteers (n = 11) and showed that cerebellar intermittent theta burst stimulation (iTBS) affected vestibulocerebellar neural activity. Then, between September and December 2015, we enrolled six patients (aged≥20 years) with chronic post-LMI dizziness (duration≥6 months), applied cerebellar rTMS (iTBS for 5 days), and followed these patients up for up to 25 months for clinical symptoms (Dizziness Handicap Inventory [DHI]), signs (nystagmus), and VOR gain. Results Four of the six patients completed the study without complications. After rTMS, DHI scores were reduced (mean pre-rTMS DHI score minus post-rTMS DHI score was 13.0 [P = 0.036]) with disappearance of the ipsilesional nystagmus characteristic of the post-LMI dizziness. Reduction in the absolute VOR gain (mean pre- rTMS gain minus post-rTMS gain in the ipsilesional direction was 0.135 [P = 0.036] and that in the contralesional direction was 0.137 [P = 0.031]) were also associated with reduced DHI scores. Relative cerebellar blood flow to the brainstem was increased in four of five patients. The effects of cerebellar rTMS did not always persist, and three of four patients elected to undergo more than one rTMS series. The repeat cerebellar rTMS treatments had same beneficial effects. Conclusion Our study showed, for the first time, the potential efficacy of cerebellar rTMS for treatment of chronic post-LMI dizziness. The short duration of the cerebellar rTMS effects can be compensated for by repeating the rTMS treatment every few months. Further large-scale randomized studies are warranted to confirm our findings.

Background Bow hunter's syndrome (BHS) is rare and typically induced by mechanical compression of the dominant vertebral artery (VA) during head rotation. We report a case of BHS induced by nondominant VA compression in which contralateral VA patency was preserved. Definite diagnosis of BHS is not often feasible because of transient symptoms and nonspecific clinical features, such as vertigo or dizziness, especially in nondominant VA compression. We discuss the diagnostic clues of BHS and clinical features of BHS caused by nondominant VA compression through a literature review. Case Description A 65-year-old man suffered repeated bouts of dizziness whenever his head was rotated to the left. This dizziness was consistently accompanied by downbeat nystagmus (DBN). Radiography revealed left VA compression by a lateral osteophyte at the C3-C4 level only during left head rotation. In contrast, patency of the right VA, which was almost equivalent in size to the left VA, was preserved during head rotation. The distinctive clinical finding of head rotation-induced DBN, which is usually associated with lesions involving the caudal midline cerebellum, was observed. Symptoms disappeared immediately after left VA decompression with osteophytectomy and C3-C4 fusion. Conclusions Despite excellent flow through the contralateral VA, occlusion of the nondominant VA occasionally induces BHS. According to a review of the literature, BHS cases do not always depend on the VA on one side for blood supply. Head rotation–induced DBN can be useful for diagnosis of BHS, even in cases of nondominant VA compression.

Background and purpose Repetitive transcranial magnetic stimulation (rTMS) is reported to improve chronic post-stoke hemiparesis. However, application of rTMS during the acute phase of post-stroke has not fully been investigated. We investigated the safety and the efficacy of intermittent theta-burst stimulation (iTBS) of the affected motor cortex and 1-Hz stimulation of the unaffected hemisphere during the acute phase in patients with hemiparesis due to capsular infarction. Methods Twenty one patients who met the study criteria were randomly assigned to receive, starting within 7 days after stroke onset and for a period of 10 days, iTBS of the affected motor cortex hand area (n = 8), 1-Hz stimulation of the unaffected motor cortex hand area (n = 7), or sham stimulation (n = 6). Upper limb motor function was evaluated before rTMS and 12 weeks after onset of the stroke. Evaluation was based on the Fugl-Meyer Assessment (FMA), Stroke Impairment Assessment Set (SIAS), Modified Ashworth Scale (MAS), grip strength, and motor evoked potential (MEP) amplitude in the first dorsal interosseous (FDI) muscle. Results Both iTBS applied to the affected motor cortex hand area and 1-Hz stimulation applied to the unaffected motor cortex hand area enhanced motor recovery. In comparison to sham stimulation, iTBS increased the SIAS finger-function test score, and 1-Hz stimulation decreased the MAS wrist and finger score. Conclusions Ipsilesional iTBS and contralesional 1-Hz stimulation applied during the acute phase of stroke have different effects: ipsilesional iTBS improves movement of the affected limb, whereas contralesional 1-Hz stimulation reduces spasticity of the affected limb.

Background and purpose Delirium frequently complicates acute stroke and worsens outcomes. Because delirium is potentially preventable, predicting its occurrence is essential. Although several prediction scores have been proposed, nurses need to quickly predict delirium in stroke care units (SCUs). We aimed to develop a simple tool for this purpose by examining a comprehensive set of potential predictors. Methods This is a prospective cohort study on acute stroke patients admitted to an SCU. Patients without stupor, coma, or delirium upon admission were eligible. Participants were followed for 5 days from admission. Delirium was defined as Intensive Care Delirium Screening Checklist ≥4 points. We examined 27 potential predictors, of which 13 predictors were used to developed a least absolute shrinkage and selection operator-penalized logistic regression model. Five variables with the largest coefficients were assigned one point each in the prediction score. The internal validation was performed by bootstrapping. Results Delirium occurred in 42 of the 387 participants. The score consisted of prior delirium, alcohol, NIHSS ≥5, dementia, and auditory/visual impairment (PANDA). The apparent AUC was 0.84 (95% confidence interval [CI], 0.78–0.89), and the optimism-corrected AUC was 0.81 (95% CI, 0.73–0.88). With a cutoff of ≥2 points, sensitivity was 0.78 (95% CI, 0.65–0.90), and specificity was 0.74 (95% CI, 0.70–0.79). Conclusions PANDA score is simple and predicts delirium in an SCU satisfactorily.

In eye movement examination, video-oculographic monocular recording has become more popular than electro-oculographic binocular recording. The aim of this study was to examine the characteristics of monocular movements recorded using video-oculography. In 66 healthy subjects, the horizontal saccades and smooth pursuit eye movements of the right eye within a range of 30o were evaluated using a video-oculographic eye movement recording system. Saccade latency, velocity, accuracy, and smooth pursuit gain were measured and analysed by age and direction. Saccade parameters (latency, velocity, and amplitude) and smooth pursuit gain deteriorated with age in healthy subjects. Saccade velocity and accuracy were significantly larger during adduction than during abduction. The smooth pursuit gain did not differ between adduction and abduction. In conclusion, unlike smooth pursuit eye movements, saccadic eye movements have adduction-abduction asymmetry. In video-oculographic monocular recording of saccades, it is necessary to recognise the possibility of the existence of adduction-abduction asymmetry.

Background and purpose The presence of hemispatial neglect adversely affects functional outcomes in stroke patients; consequently, it warrants early targeted rehabilitative intervention. Nevertheless, hemispatial neglect in the acute phase of stroke has often been underdiagnosed. In this study, we aimed to detect hemispatial neglect at the bedside in acute stroke patients by measuring eye movements using video-oculography (VOG). Methods Forty-seven patients with acute unilateral supratentorial stroke were enrolled. We quantitatively measured horizontal saccade (latency, velocity, and amplitude) and smooth pursuit (gain) at the bedside using VOG and compared these variables with scores on the Behavioral Inattention Test (BIT), a screening battery to assess hemispatial neglect. Results Contralesional saccade latency, velocity, and amplitude, and ipsilesional smooth pursuit gain were suppressed compared with those in the opposite directions (p = 0.08, 0.02, 0.04, and 0.02, respectively). These directional ocular hypokinesia values correlated with the total BIT score (correlation coefficients −0.53, 0.48, 0.51, and 0.39, respectively). The association was significant even after adjusting for age and stroke severity. Conclusions Eye movement measurements performed using VOG significantly correlated with the tendency for hemispatial neglect in acute supratentorial stroke patients. Bedside VOG measurement may be a simple biomarker for detecting hemispatial neglect even in patients in the supine position during the acute phase of stroke.

Background and purpose Uncomfortable care and histamine H2 antagonist (H2A) are implicated in precipitating delirium. In acute stroke, however, the need for them depends on stroke severity, an established risk factor for delirium. So, it is unclear whether care or H2A itself is responsible for delirium. We aimed to evaluate their causal effects on delirium in acute stroke patients. Methods This is a prospective cohort study on acute stroke patients admitted to a stroke care unit. Patients without stupor, coma, sedation, or delirium upon admission were enrolled. The treatment was H2A and five care modalities given during the first 24 h: restraint use, prohibited self-transfer, no oral feeding, indwelling catheters, and frequent nighttime care. The outcome was delirium within 5 days defined as Intensive Care Delirium Screening Checklist ≥4 points. We estimated the relative risk (RR) for delirium with regression models weighted by overlap weights using propensity scores estimated through logistic models incorporating known and potential confounders, including stroke severity. Results Of the 387 participants, 188 were given at least one care modality and 130 were given H2A. A total of 42 developed delirium. Delirium was significantly associated with prohibited self-transfer (RR 1.7, 95% CI 1.0–3.0), frequent nighttime care (RR 2.1, 95% CI 1.2–3.7), and multiple care modalities (RR 2.4, 95% CI 1.3–4.4), while other care modalities and H2A were not. Conclusions This study showed possible causal effects of uncomfortable care on delirium and suggests that minimizing it could prevent delirium in acute stroke.

Introduction: Brainstem stroke sometimes causes long-lasting dizziness. A cerebellar control disorder of the vestibulo-ocular reflex (VOR) has been postulated as a mechanism of dizziness in such patients. We conducted a proof-of-principle cohort study to assess the potential efficacy of cerebellar repetitive transcranial magnetic stimulation (rTMS) as treatment for long-lasting post-brainstem stroke dizziness. Methods: We first applied cerebellar rTMS in healthy volunteers (n=11) and showed that cerebellar intermittent theta burst stimulation (iTBS) affected vestibulocerebellar neural activity. Then, we enrolled 11 patients with long-lasting post-brainstem stroke dizziness (lateral medullary infarction, 9; lateral pontine infarction, 1; and lateral pontine hemorrhage, 1), applied cerebellar rTMS (iTBS for 5 days), and followed these patients up for clinical symptoms (Dizziness Handicap Inventory [DHI]), signs (nystagmus), and VOR gain. Results: After rTMS, DHI scores were significantly reduced with disappearance or attenuation of the ipsilesional nystagmus characteristic of the long-lasting post-brainstem stroke dizziness. Reduction in the absolute VOR gain was also associated with reduced DHI scores. Relative cerebellar blood flow to the brainstem, measured in 4 patients, was increased. However, the effects of cerebellar rTMS did not always persist. Conclusion: Our study showed the potential efficacy of cerebellar rTMS for treatment of long-lasting post-brainstem stroke dizziness. Further large-scale randomized studies are warranted to confirm our findings.

We report a case of an anomalous anastomosis formed between the external carotid artery (ECA) and the vertebrobasilar artery (VBA) and passing through the hypoglossal canal. A carotid-vertebrobasilar anastomosis of this kind is typically considered a variant of persistent primitive hypoglossal artery which usually originates from the internal carotid artery. However, the anastomotic vessel in this case had a common trunk with the occipital artery (OA), a remnant of the primitive proatlantal artery. The proximal and distal parts of the anastomotic vessel seemed to have been derived from the primitive proatlantal artery and the primitive hypoglossal artery, respectively. Thus, we propose that this ECA-VBA anastomosis, which passed through the hypoglossal canal and had a common trunk with the OA, be referred to as a dilated primitive hypoglossal-proatlantal anastomosis; that is, a dilated ascending pharyngeal artery rather than a variant of persistent primitive hypoglossal artery.

The risk of atrial fibrillation (AF)-related stroke is usually assessed by calculating the CHA2DS2-VASc score, the components of which are various risk factors, including prior stroke. Although prior stroke is considered the strongest risk factor, the associated risk is actually inferred. Nevertheless, it implies a "freedom-from-event effect" (FEE)-the longer a patient is stroke-free, the lower the stroke risk. Although dynamic prognostication has been applied to cancer, the FEE has been ignored in AF, probably because of methodological difficulties. We conducted a simulation study to evaluate the FEE in the risk of AF-related stroke. We modeled various populations of AF patients and simulated the development of stroke assuming a nonhomogeneous Poisson process, where the hazard depends on age, comorbidities, and individual variability. Parameters were set so that the model respects the CHA2DS2-VASc scoring scheme and reproduces the 1-year CHA2DS2-VASc score-wise stroke risk and relative risk conferred by real-world risk factors. We tracked stroke risk over 0 to 15 years of freedom-from-stroke time (FST), both prospective FST (pFST), which begins at the time of diagnosis and continues to the future, and retrospective FST (rFST), which begins at the present and looks backward to the time of diagnosis. The pFST counterbalanced the increase in stroke risk conferred by aging; in patients with a CHA2DS2-VASc score of 1, the pFST offset 62% of the age-conferred risk increase. The rFST reduced the stroke risk; in patients with a CHA2DS2-VASc score of 2 and without prior stroke, an rFST of 6.8 years reduced the stroke risk to the midpoint between CHA2DS2-VASc scores 1 and 2. The study results suggest that the FEE should be considered in evaluating stroke risk in patients with AF. The FEE may be important in other recurrent diseases for which a prior event is a risk factor for a future event.

The utility of light transmission aggregometry (LTA)-based assessment of platelet function in acute ischemic stroke patients remains controversial. This study aimed to clarify why LTA failed to estimate platelet function in acute ischemic stroke patients.Using LTA, we evaluated the platelet aggregation abilities of citrated blood samples from 22 acute noncardiogenic ischemic stroke patients prior to treatment and compared them with those of 65 heathy volunteer controls. Platelet counts and mean platelet volumes (MPV) of citrated blood and platelet-rich plasma (PRP) prepared for LTA were evaluated simultaneously. Using a hematology analyzer, we also measured and compared the aggregation-prone properties of platelets in the hematology analysis process between patient and control samples.Although platelets aggregated more easily and frequently in patient samples (P .01), the maximum aggregation rate (MA%) of LTA was paradoxically lower in patients than in controls (P .05). The PRP/citrated blood ratio of platelet counts and MPV were significantly lower in patients than in controls (P .05).Our results suggest that MA% of LTA is erroneously displayed as lower values than the actual status in patients with increased platelet aggregation ability such as acute ischemic stroke because activated large platelets are preaggregated and thus decreased in the PRP on LTA.

Background and Purpose: Although ataxic hemiparesis is a common lacunar syndrome, the precise mechanism underlying hemiataxia is not clear. We attempted to identify ataxia-related, cerebral blood flow changes in patients presenting with ataxic hemiparesis after acute capsular infarct. Methods: We used 99mTc-ECD brain perfusion single-photon emission computed tomography to evaluate regional cerebral blood flow in 12 patients with ataxic hemiparesis caused by capsular infarct, and we compared the regional blood flow of these patients with that of 11 patients with pure motor hemiparesis caused by similar lesions. Results: The ipsilateral red nucleus blood flow was significantly decreased in the ataxic hemiparesis patients, whereas the ipsilateral red nucleus blood flow was increased in the pure motor hemiparesis patients. Crossed cerebellar diaschisis (decreased contralateral cerebellar blood flow) was seen in ataxic hemiparesis patients; similarly, it was seen in pure motor hemiparesis patients. Conclusions: Our findings suggest that ataxia in hemiparetic patients with capsular infarct can be caused by ipsilateral red nucleus dysfunction secondary to cortico-rubral pathway disruption at the internal capsule. i 2014 S. Karger AG, Basel

Hypoglycemia may cause acute hemiplegia. The most common diffusion-weighted MR imaging finding in patients with hypoglycemic hemiplegia is the hyperintense lesion involving the internal capsule, mimicking acute ischemic stroke. Thus, in patients with acute onset hemiplegia, it is important to differentiate hypoglycemia on arrival by immediate blood glucose measurement. It has recently been shown that hypoglycemic brain injury start in large white matter tracts such as internal capsule and spread throughout the whole brain, including the gray matter. However, it is still unclear why focal signs such as hemiplegia develope in metabolic disorders affecting the whole brain.

The risk factors among the types of ischemic stroke (atherothrombotic cerebral infarction: ATI, cardio-embolic infarction: CEI, lacunar infarction: LI) in aged stroke patients have rarely been compared to each other.We compared the clinical parameters of 300 elderly patients with ischemic stroke, age 65-98years, to 100 age-matched control patients.Comparison by parametric test and logistic regression analysis between all 300 and 100 control patients showed higher systolic and diastolic blood pressures (p0.001, p=0.03), lower estimated glomerular filtration rate (eGFR) (p=0.01), larger cardiothoracic ratio (CTR) (p0.001), smoking (p0.01) and possibly poor adherence to anti-hypertensive agents in the ischemic stroke patients (p0.001). Comparisons among three types (n=100 for each) showed the highest atheromatous risk factors for ATI to be hemoglobin A1c (p=0.01) and low-density lipoprotein (p0.001) and for CEI to be largest cardiac load, indicated by largest left atrial dimension (p0.001), and CTR (p0.001). Triglyceride level was found to be a borderline risk factor for LI (p=0.054). Comparison between those aged74 versus ≥75years (n=150 for each) showed a lower eGFR (p=0.02) and larger right atrial dimension (p0.001) in patients ≥75.The risk factors were quite different among the subtypes and aging.

Lateral medullary infarction (LMI) sometimes causes long-lasting dizziness. However, the characteristics of nystagmus in patients with post-LMI dizziness are unknown. We undertook a prospective, comparative study of nystagmus in patients with and without post-LMI dizziness to determine the characteristic pattern of nystagmus of chronic post-LMI dizziness.We evaluated and compared nystagmus under spontaneous, head-shaking, and positional testing conditions in 12 patients with post-LMI dizziness and in 6 patients without post-LMI dizziness.In the dizziness group, contralateral spontaneous nystagmus, ipsilateral head-shaking nystagmus, and horizontal direction-changing geotropic positional nystagmus were observed in patients in whom the LMI had occurred60days previously (subacute period). In patients with dizziness in whom the LMI had occurred90days previously (chronic period), the nystagmus was ipsilateral under all conditions. In the non-dizziness group, ipsilateral nystagmus was observed in 1 of the 2 subacute patients only after head-shaking and in 1 of the 4 chronic patients only during positional testing.Ipsilateral nystagmus observed under all spontaneous, head-shaking, and positional testing conditions characterizes chronic post-LMI dizziness.

We assessed the clinicopathological features of nine patients with pure autonomic neuropathy, that is, neuropathy without sensory or motor deficits. The duration from symptom onset to diagnosis ranged from 1 month to 13 years. Of eight patients in whom serum antiganglionic acetylcholine receptor antibody was determined, four were positive. All patients who tested positive for this antibody manifested widespread autonomic dysfunction, with the exception of one patient who only experienced orthostatic hypotension. However, patients who were negative for the antiganglionic acetylcholine receptor antibody presented with partial autonomic failure. One of these patients had diffuse parasympathetic failure and generalized hypohidrosis but no orthostatic hypotension, which is clinically compatible with postganglionic cholinergic dysautonomia. Electron microscopic examination revealed a variable degree of reduction in unmyelinated fibers. Compared with normal controls, the patients had a significantly increased density of collagen pockets (p < 0.05). Additionally, the percentage of Schwann cell subunits with axons (out of the total number of Schwann cell subunits associated with unmyelinated fibers) was significantly decreased (p < 0.01). The density of unmyelinated fibers tended to decrease with increasing time between the onset of autonomic symptoms and biopsy (p < 0.05). In conclusion, the clinical and pathological features of pure autonomic neuropathy vary in terms of progression, autonomic involvement, presence of the antiganglionic acetylcholine receptor antibody, and loss of unmyelinated fibers.

Background and purpose Unilateral saccadic pursuit is reported to be suggestive of a pontine lesion in sensory stroke patients. We attempted to verify this eye sign in just-hospitalized pontine sensory stroke patients. Methods Horizontal smooth pursuit eye movements were evaluated upon hospital arrival in 4 pontine sensory stroke patients and were compared with those in 6 thalamic sensory stroke patients. Eye movements were evaluated with the patient lying down on the emergency room or stroke care unit bed by means of a newly developed video-oculography-based eye movement recording system equipped to project a moving laser pointer onto the ceiling. Results Laterality of horizontal smooth pursuit gain in pontine sensory stroke patients was evident upon arrival; in thalamic sensory stroke patients, horizontal smooth pursuit gain was equal in both directions. These characteristics were easily detected at bedside. Conclusion Unilateral saccadic pursuit in pontine sensory stroke patients may be a practical diagnostic sign that can be detected even in the emergency room. The video-oculography-based recording system equipped to project a moving laser pointer onto the ceiling may be useful for detecting this eye sign.

Infarction in the genu of the internal capsule causes dementia that is characterized by abulia, lethargy and memory loss without obvious motor palsy (capsular genu syndrome). We found infarction or decreased cerebral blood flow in the genu of the internal capsule in 6 of 13 patients with severe bacterial meningitis. Four of these six patients developed post-meningitis dementia, characterized by abulia, lethargy, and memory loss. Of 24 patients with viral meningitis, none developed capsular genu ischemia or post-meningitis dementia. In patients with severe bacterial meningitis, capsular genu ischemia may play some role in the development of post-meningitis dementia. In patients with viral meningitis, absence of such ischemia may explain, at least in a part, the rarity of post-meningitis dementia.

Ruptured vertebrobasilar dissecting aneurysm is usually treated surgically because rebleeding negatively affects outcome. However, the risk of rebleeding decreases markedly once several hours have passed from the initial bleeding. Moreover, surgery-related complications are not rare. We describe seven patients with ruptured vertebrobasilar dissecting aneurysm. To prevent rebleeding during the acute stage, we treated all seven patients conservatively with fentanyl instead of emergency surgery. During the follow-up period (mean 20 months), no patient suffered rebleeding. Conservative treatment with fentanyl administration may be a good option for management of ruptured vertebrobasilar dissecting aneurysm during the acute stage.

In patients receiving chronic warfarin therapy, the international normalized ratio of prothrombin time (PT-INR) reportedly correlates with the incidence, size, severity, and outcome of ischemic stroke, and thus there are guidelines for the optimal PT-INR range that is to be maintained during secondary or primary prevention of ischemic stroke. However, the details of ischemic stroke in patients in whom an optimal PT-INR is maintained by warfarin therapy have not been thoroughly investigated. We conducted a retrospective study to determine the predictors of the size, severity, and outcome of ischemic stroke occurring in patients under chronic warfarin therapy and maintenance of an optimum PT-INR.The study group comprised 22 consecutive acute ischemic stroke patients who were receiving warfarin and whose PT-INR was within the optimal range on admission. The PT-INR and plasma D-dimer level of these patients on admission were analyzed in relation to infarction volume, National Institutes of Health Stroke Scale score on admission, and modified Rankin Scale score at discharge.PT-INR did not correlate with infarction volume, severity, or outcome. The D-dimer level correlated positively and significantly with the volume (r = .49, P .05), severity (r = .54, P .05), and outcome of ischemic stroke (r = .61, P .01) and did not correlate with the PT-INR (r = -.27, P = .23).When the PT-INR is within optimal range in patients receiving chronic warfarin therapy but who suffer an ischemic stroke, the admission D-dimer level, but not PT-INR, correlates with the size, severity, and outcome of the stroke. Thus, monitoring the D-dimer level in patients receiving long-term warfarin therapy is important, regardless of whether the optimal PT-INR is maintained.

A pseudo-subarachnoid hemorrhage (pseudo-SAH) is a brain computed tomography (CT) finding that is seen as high-density areas along the basal cisterns, the sylvian vallecula/fissure, the tentorium cerebella, or the cortical sulci, although no SAH is found upon lumbar puncture or at autopsy. There is one report of cryptococcal meningitis presenting as pseudo-SAH, but the explanatory pathology is unknown. A 68-year-old woman with headache, fever, decreased hearing, and decreased vision was admitted to our hospital. Cerebrospinal fluid India ink staining was positive, and culture yielded Cryptococcus neoformans. Cryptococcus meningitis was diagnosed. Head CT and magnetic resonance imaging (MRI) showed no abnormality upon admission, but 1 month later, head CT showed iso- to high-density areas within the sulci, and fluid-attenuated inversion recovery MRI showed high signal intensity within the convexity sulci resembling an SAH. These areas were enhanced by gadolinium on T1-weighted images. Lumber puncture produced no evidence of bleeding. Biopsy of the left frontal lobe sulci was performed, and histopathological study revealed inflammation and granulation with capsules of C. neoformans. The inflammation and granulation at the convexity sulci induced by the C. neoformans infection explained the pseudo-SAH in this case. Physicians should be aware that cryptococcal meningitis-induced inflammation and granulation at the sulci can present as pseudo-SAH on CT and MRI.

Vertical eye deviation in hypoxic coma is considered to be rare. In contrast, we found that in a consecutive series of 50 postresuscitation comatose patients, 28 (56.0%) developed tonic upward or downward eye deviation. We suggest that both the upward and the downward deviations resulted from diffuse cerebrocerebellar damage sparing the brainstem. Upward deviation is an early sign, whereas downward deviation appears later and generally implies a transition to the vegetative state.

A 37-year-old man developed an acute encephalitic condition after respiratory infection. His condition rapidly deteriorated, and he experienced ophthalmoplegia, tetraplegia, loss of brainstem reflexes and deep tendon reflexes, and deep coma. Electrophysiological evaluations indicated involvement of the peripheral nerve as well as the brainstem. Follow-up studies found acute progression of peripheral nerve damage. Serum anti-GQ1b IgG antibody was present. The initial condition was diagnosed as Bickerstaff's brainstem encephalitis, and subsequent overlapping of Guillain-Barré syndrome probably was responsible for the clinical deterioration. When unusual worsening is observed in clinically suspected encephalitis, neurologists must take into account the possibility of associated Guillain-Barré syndrome and related disorders.

After an episode of vasodilator-induced systemic hypotension, a 75-year-old man developed ocular lateropulsion to the right, left-side-dominant quadriparesis, loss of superficial sensation below C4 dermatome level, and anuresis. Magnetic resonance imaging (MRI) showed infarcts in the right cerebellar hemisphere (posterior inferior cerebellar artery territory) and the upper cervical cord (anterior spinal artery territory); the combination of posterior inferior cerebellar artery (PICA) and anterior spinal artery (ASA) infarcts has not been reported previously. Angiography revealed severe stenosis in the bilateral vertebral arteries. Hemodynamic hypoperfusion of the stenotic vertebral arteries may cause this unusual combination.

Background and purpose Unilateral gaze palsy associated with internuclear ophthalmoplegia (INO), i.e., one-and-a-half syndrome, is well known. Exotropia can also be associated with INO, but it has been reported only rarely. We sought to determine the frequencies and courses of gaze palsy and exotropia in INO. Methods Patients hospitalized with acute-onset INO during the period January 2009 through December 2013 were identified from our clinical registry. Associated gaze palsy and exotropia were evaluated in the identified patients. Results Twenty-five patients with unilateral INO and 7 patients with bilateral INO were included in this study. Of the 25 patients with unilateral INO, 4 (16.0.0%) had ipsilateral gaze palsy (one-and-a-half syndrome), 8 (32.0%) had exotropia (non-paralytic pontine exotropia), and 6 (24.0%) had both ipsilateral gaze palsy and exotropia (paralytic pontine exotropia). Six (85.7%) of the 7 patients with bilateral INO had exotropia. The gaze palsy persisted more than 1 week in 40.0% of patients, whereas the exotropia disappeared within 1 week in 92.9% of patients when the INO was unilateral. Conclusion Exotropia is not uncommon in the acute stage of INO. However, it is often overlooked because of its short duration.

We describe the case of a 72-year-old man who presented with dementia that had progressed rapidly over a few months. Laboratory analysis of blood and cerebrospinal fluid (CSF) showed no abnormalities, with the exception of a slightly increased CSF protein level. Results of routine magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) and magnetic resonance angiography (MRA) were unremarkable. However, detailed neuroimaging studies including contrast-enhanced T1-weighted MRI and conventional angiography revealed a superior sagittal sinus (SSS) dural arteriovenous fistula (DAVF). After endovascular embolization and surgical interruption of all arteries feeding the DAVF, the dementia reversed. We should be aware of the possibility of DAVF as the cause of rapidly progressive dementia even if routine MRI reveals no or only minimal abnormality.