Biomedical subjects
Publications and source records attributed to R Neshige.
We describe a case of Burkitt's cell acute lymphoblastic leukemia presenting with the bilateral numb chin syndrome as the initial symptom of the disease. Postmortem study of the trigeminal nerve showed heavy infiltrations of leukemic cells and destruction of axon and myelin by leukemic cells in the mandibular nerve.
A 52-year-old woman, who had ischemic infarction in the ventral upper brainstem due to subarachnoid hemorrhage in October 1986, had recurrent sleep and cataplexy attacks from May 1987. She was receiving valproate and phenytoin daily since 1986. The diagnosis of narcolepsy was made based on the clinical symptoms and EEG findings showing REM sleep during a sleep attack. Both sleep and cataplexy attack increased in parallel with an increase of the dose of anti-convulsant drugs and disappeared immediately after the discontinuation of the treatment. The findings that suggest that the administration of anti-convulsant drug as well as the brainstem vascular lesion was deeply involved in the development of narcolepsy in this case.
A new method for evaluating the recovery function of evoked potential (EP) in real time was reported. To record the test response of paired stimulation, the responses to alternate presentation of unpaired stimulus and several kinds of paired stimuli with various interstimulus intervals were averaged respectively and subtraction was made in real time. The EP's to the test stimulus obtained by the proposed method were proved to be accurate even under the changing recording conditions. A formula for computing the recovery correlation factor was derived as a measure of the recovery function of the recorded EP, and the recovery curves for three subjects were obtained.
To elucidate the sensitivity to pain stimuli in patients with cortical reflex myoclonus, pain-related somatosensory evoked potentials (pain SEPs) following CO2 laser stimulation and conventional electrically-stimulated SEPs (electric SEPs) were compared in four patients with cortical reflex myoclonus. The P25 peak of electric SEPs was considerably enhanced but the P320 potential of pain SEPs was of normal amplitude in all patients. After medication, myoclonus was reduced and the amplitude of P25 was decreased, but P320 showed no change. In our previous study of the scalp distribution in normal subjects, a subcortical site, probably the thalamus, was considered to be the generator source of P320. Because most pain stimuli do not reach the cortex, patients with cortical reflex myoclonus are not sensitive to pain stimuli and P320 in pain SEPs is not enhanced.
Two patients with action tremor that was thought to originate in the cerebral cortex showed fine shivering-like finger twitching provoked mainly by action and posture. Surface EMG showed relatively rhythmic discharge at a rate of about 9 Hz, which resembled essential tremor. However, electrophysiologic studies revealed giant somatosensory evoked potentials (SEPs) with enhanced long-loop reflex and premovement cortical spike by the jerk-locked averaging method. Treatment with beta-blocker showed no effect, but anticonvulsants such as clonazepam, valproate, and primidone were effective to suppress the tremor and the amplitude of SEPs. We call this involuntary movement "cortical tremor," which is in fact a variant of cortical reflex myoclonus.
We administered alpha-interferon (alpha-IFN) and gamma-globulin (gamma-gl) to patients with HTLV-I-associated myelopathy (HAM). Patients selected for this study fulfilled the diagnostic criteria of HAM by Osame et al. As for alpha-IFN, 12 patients were injected intramuscularly with a dose of 3 X 10(6) IU/day of alpha-IFN for 28 days. As for gamma-gl, 10 patients were injected intravenously with a dose of 10 g/day of human gamma-gl for 5 days. alpha-IFN exerted therapeutic effects in 7 of 12 patients and gamma-gl in 6 of 10. The therapeutic effects were shown by the improvement in time for a 20-meter walk, muscle power of lower limbs and urinary frequency. All patients having a history of improvement by corticosteroid therapy showed beneficial responses to both treatments with alpha-IFN and gamma-gl. Contrarily, patients who had not improved by corticosteroid therapy did not show any improvement after gamma-gl and alpha-IFN administration. The therapeutic effects of gamma-gl and alpha-IFN were observed predominantly in cases with shorter duration of illness, more marked abnormality in cerebral MRI findings and higher CSF antibody titers to HTLV-I. There was no correlation between the therapeutic efficacy and clinical severity or serum antibody titers to HTLV-I. We conclude that therapies with alpha-IFN and gamma-gl were safe and effective for the treatment of HAM.
A 34-year-old women without history of seizures was admitted to our hospital because of the diminished responsiveness and the repeated blinking for two days. Her past history showed neither surgery nor inflammation of the thyroid gland. General physical examination was normal. On neurological examination, the patient was blinking frequently and staring without any responsiveness. However, she occasionally became able to respond correctly to verbal orders, such as "open your eyes", "open your mouth", "stand up" and so on, which occurred abruptly just like the switch-on. She was otherwise normal neurologically. The laboratory data showed hypocalcemia, hyperphosphatemia, decreased level of parathyroid hormone and normal renal function, indicating the presence of idiopathic hypoparathyroidism. EEG showed the continuous generalized 2-4 Hz spike and wave complexes with the maximum intensity on frontal lobes. Skull roentgenograms and MRI CT of the head disclosed hyperostosis frontalis interna (HFI) and the compression of superior medial frontal lobes by the HIF. SPECT also showed the diminished circulation and hypometabolism in the superior frontal lobes. Based on clinical and EEG findings, the diagnosis of spike-wave stupor was made. She was successfully treated with valproic acid and ethosuximide. Spike and wave complexes on EEG completely disappeared after administration of alfacalcidole. It is assumed that both hypoparathyroidism and HFI were deeply involved in the development of spike-wave stupor in this adult case.
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A patient with intractable epilepsy secondary to a brain tumor was evaluated with a chronically implanted array of 64 stainless-steel subdural electrodes covering the perirolandic area. Cortical potentials associated with voluntary, self-paced middle-finger extension were recorded simultaneously from subdural and scalp electrodes using a computer-assisted method for averaging movement-related potential (MRP) in relation to electromyographic (EMG) onset. A high-amplitude negative potential, Bereitschaftspotential/negative slope (BP/NS'), preceding the onset of the EMG activity by more than 1 sec was recorded in an extremely localized fashion exclusively from electrodes placed in the precentral hand motor area as well as in the more medial part of the somatosensory hand area. These results suggest that the hand motor and sensory areas have an essential participation in the generation of MRPs and, therefore, also in the preparation of voluntary finger movements.
An auditory discrimination paradigm was employed to elicit event-related brain potentials in 13 patients with Alzheimer's disease and 14 patients with multi-infarct dementia. The P300 latency was significantly prolonged in 12 patients with dementia compared with age-matched controls and showed a significant negative correlation with the score of Wechsler Adult Intelligence Scale (WAIS), especially with that of Digit Span subtest. There was no disease specificity. After physostigmine treatment, P300 latency decreased and WAIS score increased in 6 among 10 cases.
We studied the scalp distribution of auditory event-related potentials (P300), using simultaneously a cephalic (linked ears) and a noncephalic (balanced sternovertebra) reference. The recordings with noncephalic reference showed that infrequent, attended auditory stimuli evoke a negative bitemporal component (N300) as well as a positive vertex component (P300).
Movement-related cortical potentials (MRPs) were recorded from scalp electrodes in 8 normal volunteers and from chronically implanted subdural electrodes in 7 patients who were being evaluated for surgical treatment of epilepsy. From subdural electrodes, a clearly defined, extremely localized slow negative potential preceding the voluntary movement of the middle finger (Bereitschaftspotential, BP) was recorded in the contralateral and ipsilateral hand sensorimotor areas. The negative slope (NS') began approximately 250 to 400 ms before EMG onset and was recorded exclusively from the contralateral hand sensorimotor area. Both BP and NS' were maximum in the hand motor area. Although a negative slope was recorded also from the supplementary motor area, whether that particular slope corresponded to BP or NS', or both, could not be determined. Three kinds of progressively steeper negative potentials starting around the onset of the EMG were identified: (1) the 'hand motor potentials' which were seen in the contralateral hand motor area and started immediately before EMG onset and peaked 130 +/- 32 ms after EMG onset; (2) the 'hand somatosensory potentials' seen in the contralateral hand somatosensory area which started simultaneously or immediately after the EMG onset; and (3) the 'vicinity potentials' seen in the immediate surroundings of the contralateral hand area and which started after the EMG onset. The 'hand motor potentials' had the highest amplitude. From these findings, we concluded that bilateral hand sensorimotor areas and the supplementary motor area participate in the 'preparation' of movements, but that mainly the contralateral cortex generates the discharges necessary to produce the actual movement.
Three patients with flash-evoked myoclonus were studied electrophysiologically. Myoclonic jerks were elicited at a fixed latency after the application of photic stimuli and were always preceded at a fixed time interval by extremely enhanced cortical evoked potentials. The enhanced electroencephalographic (EEG) responses to flash were widely distributed over the scalp and were maximal at the central region; the occipital response preceded the frontocentral response by 3.4 to 5.1 msec. The interval from the frontocentral EEG response to the flash-evoked myoclonus was similar to that from the giant somatosensory evoked potential to the electrically evoked myoclonus. Investigation of recovery of evoked cortical responses and of myoclonic jerks showed a period of extremely enhanced excitability of both central and peripheral phenomena following stimulus. All of these findings suggest a cortical reflex mechanism. The role of the occipital cortex in the pathogenesis of photic cortical reflex myoclonus remains to be elucidated.
In order to develop an experimental paradigm for clinical application of cognitive event-related potentials we have recorded these potentials in a group of 27 healthy Japanese, aged 20-78 years, using all 4 stimulus/response combinations of auditory or somatosensory stimuli requiring a counting or button-press response. In an oddball paradigm we recorded N1 and P2 components to frequent auditory stimuli and P100, N150 and P200 components to frequent somatosensory stimuli. These components were also observed in the target responses for their respective modalities together with N2, P270, P3 and slow-wave components. P3 latency increased linearly with age for all 4 experimental conditions, although this increase was not statistically significant for the somatosensory stimulus/button-press response combination. The latency of P270 also increased significantly with age for the auditory stimulus/button-press response combination but did not do so in either of the counting response conditions. The principal difference between the latencies of ERPs to auditory compared with somatosensory stimuli was that P3 was significantly longer for somatosensory stimulation, although differences in task difficulty may have influenced this finding. With regard to amplitude, N2, P3 and slow-wave were all significantly more positive for somatosensory compared with auditory stimulation. The topography of P3 evoked by somatosensory stimuli was most predominant at central electrodes, whereas the auditory P3 was larger parietally. The button-press response was associated with potentials which were smaller in amplitude and shorter in latency than those associated with the count response. The button-press response had a marked effect on the amplitude of P3 recorded at the vertex and the central electrode contralateral to the moving finger.
Slow negative potential preceding voluntary self-paced middle finger extension, as recorded from scalp electrodes by backward averaging technique, was absent in two patients with dyssynergia cerebellaris myoclonica (Ramsay Hunt syndrome); but present in two patients with cerebellar cortical degeneration. As the main pathological lesion in Ramsay Hunt syndrome is in the dentate nucleus and its efferent pathway, the present results are in conformity with the experimental finding that the premotor and motor cortices receive strong inputs from the cerebellar efferent system.
We have recorded movement-related cortical potentials (MRCPs) to voluntary middle finger extension from 10 young and 10 old subjects free of neurological disease using the method of detecting EMG onset associated with each movement described by Barrett et al. (1985). The slow potential shifts preceding movement were measured by fitting a linear regression line to the wave forms to obtain a measure of their slope. Three separate potential shifts were identified. The first had a scalp distribution and onset latency similar to the Bereitschaftspotential (BP) first reported by Kornhuber and Deecke (1964, 1965). The potential shift immediately preceding movement corresponded with the NS' of Shibasaki et al. (1980). We identified, for the first time, a third shift intervening between BP and NS' and named it the intermediate shift (IS). The onset of BP occurred about 1.6 sec before EMG onset and was followed by IS which began about 875 msec before movement. The onset of NS' occurred 300 msec before EMG onset and terminated about 90 msec before this event. The slope of BP preceding right finger movement was steeper than that preceding left hand movement in all our right-handed subjects. The distribution of BP was symmetric about the midline. The IS potential shift had a slope which was steeper on the average preceding left finger movement than right. The distribution of IS was symmetric about the midline preceding left finger movement but had a contralateral tendency preceding right hand movement. NS' had a maximum slope at contralateral electrodes over the hand motor area and parietal areas. It was suggested that the BP potential shift originates in the supplementary motor area on the medial surface of the cerebral cortex. The differing distribution of the IS shift for the two hands suggests that this potential may be generated bilaterally preceding left finger movement but from the contralateral hemisphere only preceding movement of the right finger. The most likely origin of this potential was thought to be superior premotor cortex. NS' was considered to originate in primary motor cortex with possible contributions from other cortical areas associated with movement.
We have recorded movement-related cortical potentials (MRCPs) preceding voluntary finger extension from 10 subjects with Parkinson's disease and compared the results with those obtained from groups of young and old subjects described in the previous paper in this volume (Barrett et al. 1986). Three separate potential shifts preceding voluntary movement were identified in the wave forms of all subjects. There were no differences between the healthy aged subjects and those with Parkinson's disease in terms of the onset latencies or gradients of these potential shifts. The potential shift associated with the final phase of preparation (NS') was significantly less widespread over central scalp for the older subjects compared with the young. Equivalent results for a 35-year-old subject with Parkinson's disease were indistinguishable from those obtained from the young subjects suggesting that this restriction in the distribution of NS' is related to normal ageing rather than the disease process of parkinsonism. There were no differences within the group of parkinsonian subjects with respect to potential shifts associated with differing degrees of movement disability between the two hands. Our results contradict previous reports of abnormal MRCPs in Parkinson's disease (Deecke et al. 1977; Deecke and Kornhuber 1978; Shibasaki et al. 1978). We attribute this primarily to an improved method of recording MRCP which compensates for time jitter between EMG onset and the production of a trigger pulse for averaging (Barrett et al. 1985).
We report a case of chronic recurrent polymyositis associated with increasing antibody titers of coxsackievirus A9 in serum during clinical exacerbations. Muscle biopsy specimens showed pathologic changes consistent with chronic myositis, including perivascular mononuclear cell infiltration and hyalinization of muscle fibers with cytoplasmic vacuolations. The specific fluorescence was observed in the muscle fibers stained with antiserum for coxsackievirus A9. These findings indicate that this viral subtype as the etiologic agent in this case and virus plays a pathogenic role in some cases of chronic polymyositis.