Tsuyoshi Tsutada

Comparison of SSR and QSART in early diabetic neuropathy—the value of length-dependent pattern in QSART

We evaluated postganglionic sympathetic function using the sympathetic skin response (SSR) and quantitative sudomotor axon reflex test (QSART) on the feet of 31 patients with early diabetic neuropathy and 20 age-matched normal controls. The amplitude of SSR and the sweat volume of QSART were significantly decreased in the diabetic patients. We evaluated the sensitivity of the tests in detecting autonomic failure. Out of 31 patients, 14 (45%) had abnormal SSR (14 absent; 17 present), while 16 of 31 patients (52%) had abnormal QSART (1 absent; 5 absolutely reduced and 10 showed a length-dependent pattern of reduction). More important than differences in sensitivity is the specificity of QSART, which specifically evaluates the postganglionic axon (instead of polysynaptic pathways in SSR) and provides quantitative data on the severity and pattern of autonomic deficit. In normal controls under 65 years of age, there was a significant correlation between the amplitude of SSR and the sweat volume of QSART. However, there was no significant relationship between these in diabetic patients. These results suggest that QSART can evaluate early diabetic neuropathy more precisely than SSR.

Temporal fluctuations of voltage-gated proton currents in rat spinal microglia via pH-dependent and -independent mechanisms

Voltage-gated proton (H(+)) channels are unique mechanisms to extrude a massive amount of H(+), and are proposed to regulate intracellular pH of microglia during respiratory bursts. Temporal variations of the H(+) current were studied in rat spinal microglia cultivated on the glial cell layer using the voltage-ramp protocol. Repetitive applications of the large and long-lasting depolarization decreased the amplitudes of the H(+) current transiently and reversibly. This decrease was accompanied by a shift of the reversal potential to a more positive direction, indicating that a drop in the transmembrane pH gradient (delta pH) by the H(+) efflux through the channel reduced the current. The decline of the H(+) current during depolarizations was also observed in a rat microglial cell line (GMI-R1). An increase in the extracellular buffer suppressed the reduction of the current, suggesting that H(+) secreted into the extracellular space contributed to the drop in delta pH. On the other hand, the amplitudes of the H(+) current often fluctuated greatly at intervals of 5-20 min without changes in delta pH. These results suggest that the H(+) current of microglia is tuned via both delta pH-dependent and -independent mechanisms, which may regulate both microglial behavior and the pH environments of the surrounding neural tissue.

Determining the appropriate stimulus intensity for studying the dipole moment in somatosensory evoked fields: a preliminary study

OBJECTIVE To establish a simple method of determining the appropriate stimulus intensity for studying the dipole moment in somatosensory evoked fields. METHODS In 17 patients (20 hemispheres), the authors studied the relationship between the dipole moment and stimulus intensity, which was quantified using the threshold of thenar muscle twitch (TMT). The dipole moment was measured at 1.0, 1.5 and 2.0 TMT. Two measurements were obtained at 1.5 TMT to determine the procedures margin of error. RESULTS There was no significant difference between the dipole moments measured at 1.5 and 2.0 TMT. CONCLUSIONS Setting the stimulus intensity at 1.5 TMT or more ensures a consistent response.

Interictal Patterns of Cerebral Glucose Metabolism, Perfusion, and Magnetic Field in Mesial Temporal Lobe Epilepsy

Summary:  Purpose: To characterize the epileptogenic condition of patients with mesial temporal lobe epilepsy, the interictal patterns of glucose metabolism, perfusion, and magnetic field in the temporal lobe were evaluated by using [18F]fluorodeoxyglucose–positron emission tomography, [99mTc]‐ethylcysteinate dimer–single photon emission computed tomography, and magnetoencephalography (MEG).

Magnetoencephalography in the detection of focal lesions in West syndrome

BACKGROUND According to the international classification of epilepsy syndromes, West syndrome (WS) is a form of generalized epilepsy. However, it is known that localized lesions can induce WS and that patients with WS often subsequently develop focal seizures. We evaluated such patients using magnetoencephalography (MEG). METHOD Fourteen patients of 3 months to 6 years of age who had or who had previously had WS were examined. MEGs were recorded using a laying-type whole-cortex MEG system with a 160-channel first-order gradiometer. Twelve-channel electroencephalography (EEG) and one-channel electrocardiography (ECG) were simultaneously recorded. Equivalent current dipoles were estimated at the point of spikes on the EEG. RESULTS Patients were classified by magnetic resonance imaging (MRI) findings into a focal lesion group (group F, n=7) and a non-focal lesion group (group N, n=7). The dipoles estimated from the MEG were classified into three groups: W, with the dipoles distributed over a wide brain area (n=7); WC, dipoles distributed over a wide area along with a dense dipole distribution in a specific cortical area (n=3); and C, closed dipole distribution in a unilateral cerebral focal area (n=4). Patients were also classified by the stage of the disease during which the MEG was recorded, and by the type of seizure they experienced. Those with hypsarrhythmia examined early in the disease all had pattern W regardless of their lesion group, whereas those examined later exhibited more diverse dipole patterns that corresponded to seizure type. CONCLUSIONS Dipoles were distributed widely over bilateral cerebral cortex when patients had infantile spasms with hypsarrhythmia whether or not they had focal lesions. The dipole distribution pattern in MEG changed according to changes in seizure type.

Two cases of dementias with motor neuron disease evaluated by Pittsburgh compound B-positron emission tomography

We described the cases of two patients with dementia associated with motor neuron disease, the former with frontotemporal dementia (FTD) and the latter with Alzheimer’s disease (AD), studied by the Pittsburgh compound B-positron emission tomography (PIB-PET). In the FTD patient, the PIB-PET revealed no amyloid accumulation in the cortex, whilst in the AD patient showed amyloid accumulation mainly in the frontal, parietal and lateral temporal lobes, besides the posterior cingulate gyrus and the precuneus. Thus, PIB-PET might facilitate the discrimination of different proteinopathies that cause neurodegenerative diseases, as dementia associated with ALS.

A case of anti-N-methyl-D-aspartate receptor encephalitis with multiple sclerosis-like demyelinated lesions

OBJECTIVE To describe an unusual case of a male patient with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis who presented with multiple white matter lesions. Brain biopsy of the patient was performed, and follow-up evaluation of the cerebrospinal fluid (CSF) NMDAR antibody titer was implemented. DESIGN Case report. SETTING University hospital. PATIENT A 35-year-old man with anti-NMDAR encephalitis initially presented with fever and psychiatric symptoms. After an initial attack of anti-NMDAR encephalitis, 2 atypical relapses occurred, which presented with myelitis and multifocal white matter lesions; the lesions were open-ring-shaped and partially enhanced. INTERVENTION Analysis of the brain biopsy specimen revealed the presence of demyelinated lesions with discrete borders. Subsequent intravenous methylprednisolone therapy resulted in improvement in the brain lesions. Prednisolone and cyclophosphamide were orally administered thereafter. Clinical progression of the disease paralleled observed changes in the CSF NMDAR antibody titer. CONCLUSION The demyelinated lesions observed in this case were similar to lesions found in multiple sclerosis. On the basis of our finding that the clinical progression of the disease and the associated symptoms paralleled changes in the CSF NMDAR antibody titer, we speculate that the lesions formed as a result of anti-NMDAR encephalitis.

Detecting functional asymmetries through the dipole moment of magnetoencephalography

To assess the accuracy of magnetoencephalography (MEG) as a tool for quantitative detection of neuronal activity, the dipole moment was estimated at N20m of somatosensory evoked fields (SEFs) produced by median nerve stimulation. Neurologically stable patients were examined twice within 2 weeks. Since the estimated moment values of the two examinations should be essentially the same, we assessed the margin of error for our measurement system. The results showed that a change of more than 5.2 nAm is statistically significant (p=0.05; n=91). The patients were classified as without or with functional asymmetries by measuring the conventional cerebral blood flow (CBF) with single photon emission CT (SPECT), and the dipole moment difference between hemispheres was measured. Hemispheric moment differences were statistically larger for the group with CBF laterality, indicating consistency between conventional CBF results and the moment measurements as a group. Moreover, MEG was able to detect more functional asymmetries than CBF study. The dipole moment provided a reliable quantitative index of cortical response to somatosensory stimulus, and the moment measurement thus holds promise as a clinical tool for direct quantification of cortical response.

A case of neurosarcoidosis with recurrent brainstem infarction, obstructive hydrocephalus and brainstem atrophy

We report the case of a 42-year-old female with neurosarcoidosis who was hospitalized in year 2017 for gait disturbance. In 2011, she suddenly had vertigo that lasted for a few days. In 2013, she noticed left hemiplegia. A brain MRI revealed an acute infarction on the right side of the upper pons extending longitudinally from the ventral surface. In 2017, she again had left lower limb paralysis. A Brain MRI showed another infarction on the right side of the mid-pons. Hydrocephalus and brainstem atrophy were also noted. The patient was referred to our hospital. Upon neurological examination, she presented with down beat nystagmus, muscle weakness on the left side, and a broad-based spastic gait. CSF findings included an increased number of cells and protein levels with decreased glucose levels. A contrast-enhanced MRI revealed basilar meningitis causing hydrocephalus. A contrast CT scan revealed inguinal lymph node swelling, and scintigram found gallium accumulation. We diagnosed sarcoidosis via a lymph node biopsy. We speculate that chronic basilar meningitis obstructed the patients branching penetrating arteries inducing infarction together with obstruction of the spinal fluid flow causing hydrocephalus and cerebral atrophy.

Acute transient encephalomyelitis involving bilateral basal ganglia and internal capsules as manifestation of primary human immunodeficiency virus infection

A 25‐year‐old homosexual man presented with influenza‐like symptoms, followed by acute transient leukoencephalomyelitis as an initial presentation of human immunodeficiency virus infection, suggestive of acute disseminated encephalomyelitis. Magnetic resonance imaging showed hyperintensity in the bilateral periventricular white matter and internal capsules on T2‐weighted images, as well as an obscured boundary of the basal ganglia, which have been reported for the first time in primary human immunodeficiency virus infection.