[Show abstract][Hide abstract] ABSTRACT: A 73-year-old woman was admitted to our hospital due to a decreased conscious level and a high fever. Six days before her admission, she felt transient numbness in her right lower limb. Brain MRI taken by her local doctor revealed only right parietal cortex lesions. She was diagnosed with transient ischemic attack and started on anti-platelet therapy. One day before her admission, she became drowsy, and left-side weakness developed. She was admitted to a community hospital for treating stroke. On the next day, she was referred to our hospital because of a high fever. Our brain MRI showed new lesions in her right temporal lobe. She had no stroke risk factors, and embolic sources were not detected. Cerebrospinal fluid analysis detected herpes simplex virus DNA. She was diagnosed with herpes simplex encephalitis (HSE). HSE is common encephalitis which develops fever, headache and alteration in mental status. It often involves temporal lobe, but extratemporal lesions alone are not uncommon. Diffusion-weighted images (DWI) of brain are of importance to differentiate HSE from stroke. When it is questionable to diagnose with stroke for patients with cerebral cortex lesions, they must be monitored with close observation. There is the possibility of initial presentation of HSE in that situation even if patients have no typical symptoms.
[Show abstract][Hide abstract] ABSTRACT: Background:
The association between Parkinson's disease (PD) and body mass index (BMI) has not been established. In this study, we investigated the correlation between BMI and autonomic dysfunction in patients with PD.
Clinical features, BMI, cardiac (123)I-metaiodobenzylguanidine (MIBG) scintigraphy and the coefficient of variation of the electrocardiographic R-R interval (CVRR) were analyzed in 124 patients with PD who were naïve to anti-parkinsonian drugs.
BMI was negatively correlated with early heart-to-mediastinum ratio and CVRR in patients with PD, regardless of disease duration and severity.
Autonomic dysfunction and BMI increase were associated with each other. Physicians should consider the possibility of autonomic dysfunction in PD patients with high BMI.
No preview · Article · Jan 2016 · Parkinsonism & Related Disorders
[Show abstract][Hide abstract] ABSTRACT: Many patients from Toroku, Japan, who have chronic arsenic exposure demonstrate whole-body sensory disturbance that is slightly more pronounced in the extremities. Although previous research in this population showed a mild peripheral neuropathy, it is unknown whether these patients have central nervous system impairment. To investigate the lesion sites underlying sensory disturbance related to chronic arsenic poisoning, we analyzed somatosensory evoked potentials (SEP).
Preview · Article · Dec 2015 · Journal of the Neurological Sciences
[Show abstract][Hide abstract] ABSTRACT: Objective:
In patients with benign myoclonus epilepsy (ME), giant sensory-evoked potential (SEP) reflects the hyperexcitability of the sensory cortex. The aim of this study was to compare the effect of quadripulse transcranial magnetic stimulation (QPS) on the median nerve SEP between ME patients and healthy subjects.
Ten healthy volunteers and six ME patients with giant SEP participated in this study. QPSs at interpulse intervals (IPIs) of 5, 30, 50, 100, 500 and 1250ms were applied over the left primary motor cortex (M1) for 30min. The peak-to-peak amplitudes of N20 to P25 (N20-P25) and P25 to N33 (P25-N33) components were measured at the left somatosensory cortex.
In healthy participants, the P25-N33 was bidirectionally modulated by QPS over M1, following the Bienenstock-Cooper-Munro (BCM) theory. The N20-P25 was not affected by any QPSs. In ME patients, the giant P25-N33 was potentiated after any QPSs. Furthermore, the N20-P25 was also potentiated after QPS at IPIs of 5, 30, 50 100 or 500ms.
In ME patients, the cascade for long-term depression-like effects may be impaired.
The giant SEP was furthermore enhanced by QPS.
No preview · Article · Oct 2015 · Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology
[Show abstract][Hide abstract] ABSTRACT: In previous studies of human T-lymphotropic virus type 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), areas of slow blood flow in the spinal cord were related to pathological changes. While the pathological changes in the brain are milder than those in the spinal cord, they are also more significant in sites with slow blood flow. In this study, we investigated brain glucose metabolism in slow blood flow areas using fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET). Clinical features and brain (18)F-FDG-PET parameters were analyzed in six patients with HAM/TSP. For comparison of PET data, eight healthy volunteers were enrolled as normal controls (NLs). Glucose metabolism in the watershed areas of the middle and posterior cerebral arteries, as compared with that in the occipital lobes as a control, was significantly lower in HAM/TSP patients than in NLs. This result confirmed the relationship between slow blood flow areas and hypometabolism in HAM/TSP, and is consistent with previous findings that pathological changes are accentuated in sites with slow blood flow.
No preview · Article · Jul 2015 · Neurological Sciences
[Show abstract][Hide abstract] ABSTRACT: Abstract A 64-year-old woman with diffuse large B-cell Lymphoma (DLBCL) complained of double vision and pain sensation in her limbs after eight cycles of chemotherapy. F-fluorodexyglucose-positron emission tomography (FDG-PET) 7 days after the onset of double vision showed no abnormal accumulation and confirmed remission of DLBCL according to the international criteria. However, she developed limb weakness and severe paresthesia. The second FDG-PET 41 days after onset showed increased uptake at the both the brachial and lumbar plexuses, suggesting neurolymphomatosis. Although FDG-PET appears to be a highly sensitive diagnostic method for neurolymphomatosis, it is sometimes difficult to detect neurolymphomatosis in early diagnose, such as with this case. Therefore, multiple examinations are necessary to determine neurolymphomatosis. (Received June 2, 2014; Accepted August 20, 2014; Published February 1, 2015).
No preview · Article · Feb 2015 · Brain and nerve = Shinkei kenkyū no shinpo
[Show abstract][Hide abstract] ABSTRACT: In patients with benign myoclonus epilepsy (ME), giant sensory-evoked potential (SEP) reflects the hyperexcitability of the sensory cortex. The aim of this study was to compare the effect of quadripulse transcranial magnetic stimulation (QPS) on the median nerve SEP between ME patients and healthy subjects.
No preview · Article · Jun 2014 · Clinical Neurophysiology
[Show abstract][Hide abstract] ABSTRACT: A 46-year-old woman was admitted to our hospital with mild right-sided hemiparesis and orthostatic hypotension. Magnetic resonance angiography of the neck showed stenosis of the left distal carotid sinus surrounded by intraluminal hyperintensities on both T1-weighted and T2-weighted images, representing a periluminal hematoma secondary to carotid artery dissection. The dissection hyper-extended the carotid artery wall and stimulated baroreceptors in the carotid sinus. The stimulated baroreceptors induced carotid sinus hypersensitivity, which may have been related to her orthostatic hypotension. Post-stroke orthostatic hypotension should prompt consideration of carotid artery dissection.
Full-text · Article · Apr 2014 · Neurology International
[Show abstract][Hide abstract] ABSTRACT: Streptococcus suis (S. suis) is a zoonotic pathogen in pigs, which can be transmitted to humans by close contact. Meningitis is the most common clinical manifestations of S. suis infection and hearing impairment is a frequent complication. The risk of S. suis meningitis is higher in people who work in the swine industry. The patient was a 53-year-old woman working in the swine industry, who developed headache and fever 20 days after a swine bite. She was diagnosed as meningitis and S. suis was detected in the cerebrospinal fluid. We treated her with ceftriaxone, vancomycin, and dexamethasone, and signs of meningeal irritation diminished three days after admission. However, bilateral sensorineural hearing impairment occurred on the ninth day after admission. We added methylprednisolone (500 mg, 2 days) but moderate hearing impairment remained on the left. Antibiotic therapy should be considered for wounds of people involved in the swine industry for preventing S. suis infection.When S. suis meningitis occurs, symptoms of hearing impairment must be monitored carefully.
[Show abstract][Hide abstract] ABSTRACT: Using NIRS (near-infrared spectroscopy) and multi-channel probes, we studied hemoglobin (Hb) concentration changes when single-pulse transcranial magnetic stimulation (TMS) was applied over the left hemisphere primary motor cortex (M1). Seventeen measurement probes were centered over left M1. Subjects were studied both in the active and relaxed conditions, with the TMS intensity set at 100%, 120%, and 140% of the active motor threshold. The magnetic coils were placed so as to induce anteromedially directed currents in the brain. Hb concentration changes were more prominent at channels over M1 and posterior to it. Importantly, Hb concentration changes at M1 after TMS differed depending on whether the target muscle was in an active or relaxed condition. In the relaxed condition, Hb concentration increased up to 3-6 s after TMS, peaking at around 6 s, and returned to the baseline. In the active condition, a smaller increase in Hb concentrations continued up to 3-6 s after TMS (early activation), followed by a decrease in Hb concentration from 9-12 s after TMS (delayed deactivation). Hb concentration changes in the active condition at higher stimulus intensities were more pronounced at locations posterior to M1 than at M1. We conclude that early activation occurs when M1 is activated trans-synaptically. The relatively late deactivation may result from the prolonged inhibition of the cerebral cortex after activation. The posterior dominant activation at higher intensities under the active condition may result from an additional activation of the sensory cortex due to afferent inputs from muscle contraction evoked by the TMS.
Full-text · Article · Dec 2012 · Journal of Neurophysiology
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Imaging studies investigating repetitive transcranial magnetic stimulation (rTMS) mediated hemodynamic consequences revealed inconsistent results, mainly due to differences in rTMS parameters and technical difficulties with simultaneous recordings during rTMS. OBJECTIVE: /Hypothesis: Quadri-pulse rTMS (QPS) induces bidirectional long-term plasticity of the human primary motor cortex (M1). To evaluate its on-line effects, near infrared spectroscopy (NIRS) recordings were performed during QPS. We hypothesized that on-line effects during QPS are different from long-term aftereffects. METHODS: Using a novel TMS - on-line multi-channel NIRS setup we recorded hemoglobin concentration [Hb] changes at the stimulated M1 and adjacent sensory-motor areas during QPS protocols inducing oppositely directed aftereffects (QPS-5: interstimulus interval (ISI) 5 ms, potentiation; QPS-50: ISI 50 ms, depression). In two experiments we studied NIRS changes during either single or repeated QPS bursts. RESULTS: The repetitive QPS-5 bursts significantly decreased oxyhemoglobin concentration ([oxy-Hb]) in the ipsilateral M1. A single QPS-5 burst decreased [oxy-Hb] in the M1 and premotor cortex. QPS-50 induced no significant NIRS changes at any sites. CONCLUSIONS: QPS can significantly alter cortical hemodynamics depending on the stimulation frequency. While bidirectional long-term aftereffects of QPS reflect synaptic efficacy changes, unidirectional on-line effects during QPS may represent pure electrophysiological property changes within the cell membrane or synapse. Since neuronal postexcitatory inhibitory postsynaptic potentials typically peak within the first 10-20 ms, only pulses delivered at higher frequencies may lead to summation of the inhibitory effects, resulting in [oxy-Hb] decrease only after QPS-5. Our new TMS-NIRS setup may be valuable to investigate TMS induced neurovascular coupling mechanisms in humans.
No preview · Article · Feb 2012 · Brain Stimulation