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Biomedical subjects

R Kakigi

Publications and source records attributed to R Kakigi.

At least 145 records · Page 8Linked to original sources
PubMed1991

Correlation of SEP abnormalities with brain and cervical cord MRI in multiple sclerosis.

In 31 patients with definite or suspected multiple sclerosis (MS) presenting with a cervical cord syndrome, somatosensory evoked potentials (SEPs) were recorded to median and posterior tibial nerve stimulation, using cephalic and noncephalic reference electrodes. Magnetic resonance imaging (MRI) of the brain and cervical spinal cord was performed, the latter in sagittal and axial views. SEPs were abnormal in 67.7% of patients, whereas MRI showed cervical cord lesions in 74.2% and intracranial lesions possibly involving the somatosensory pathways in 64.5% of cases. A significant correlation was found between abnormalities of cervical (N13) and cortical (N20) potentials following median nerve stimulation with Fz reference and MRI abnormalities involving the ipsilateral or posterior half of the cervical cord, but not the contralateral or anterior half. The N13 potential, recorded from the low cervical region to a supraglottal reference, was most frequently abnormal in patients with MRI lesions at C6 or C7, whereas P14, recorded from the scalp to a clavicle reference, was most often affected by lesions at Cl or the cervicomedullary junction. Abnormalities of the cortical P40 to tibial nerve stimulation were less significantly correlated with cervical MRI lesions. The latency of N20 measured from N9 at the clavicle and the absolute latency of P40 were significantly correlated with the length of MRI abnormalities in the ipsilateral cervical cord. No significant correlation was observed between SEP abnormalities and brain MRI lesions, which it was considered might possibly involve the intracranial somatosensory pathways. It was concluded that (1) the morphological lesions seen in MRI of the cervical cord usually give rise to appropriate electrophysiological deficits, but the occasional finding of a widespread MRI lesion with normal SEP suggests that myelin damage is not the only or the major factor responsible for abnormal MRI signal; and (2) 'clinically silent' lesions apparently involving the radiations and other sensory structures of the brain appear not to give rise to detectable SEP abnormalities, using the methods of the present study.

Adult↗
PubMed1991

Pain-related somatosensory evoked potentials in syringomyelia.

Pain-related somatosensory evoked potentials following CO2 laser stimulation (pain SEPs) and conventional electrically-stimulated SEPs (electric SEPs) were examined in 8 patients with syringomyelia who showed various forms of dissociated sensory loss. Unlike clinical examination using a pin or needle, pain SEP is considered to be an objective and quantitative test to investigate functions of peripheral and central sensory pathways responsible for pain-temperature sensation (A delta fibres and the spinothalamic tract). Pain SEPs were abnormal in all patients. The results were generally compatible with the degree of a clinical impairment of pain-temperature sensation. Subclinical abnormality was detected in 3 patients. Electric median nerve SEPs using the scalp reference (Fz) were normal in 6 out of 8 patients. However, anterior and posterior cervical responses using a noncephalic reference were absent or small in 7 patients. Electric SEPs following tibial nerve stimulation were normal in 7 patients. These findings suggest that the function of the ascending fibres through the dorsal columns is intact in most patients, whereas the dorsal horn, where a fixed cervical potential is generated, is impaired. Pain SEPs combined with electric SEPs therefore appear to be extremely useful for investigating physiological function in the sensory pathways in patients who show 'dissociated sensory loss' such as in syringomyelia.

Adult↗
PubMed1991

Effects of age, gender, and stimulus side on scalp topography of somatosensory evoked potentials following median nerve stimulation.

This is the first study to evaluate the effects of age, gender, and stimulus side on scalp topography of somatosensory evoked potentials (SEPs) following stimulation of the median nerve by using computerized bit-mapped color images. Seventy-four normal subjects whose ages ranged from 7 to 88 years were studied, and Student's t test was performed on averaged mean maps and their standard deviations of each recognizable component by using the significance probability mapping method. Topographic maps of most components in aged subjects were significantly different from those in young subjects, mainly because of higher amplitudes of the components in the aged group. This difference was particularly significant for later components with the peak latencies of longer than 40 ms. Gender and stimulus side caused no significant differences in amplitude and topography of the components. Therefore, for clinical application of topographic maps of median nerve SEPs, a difference of gender and stimulus side could be disregarded, but it is necessary to consider the age effect.

Adolescent↗
PubMed1991

Neuroepithelial cyst presenting as recurrent aseptic meningitis.

A 41-year-old man had three episodes of acute aseptic meningitis from the age of thirty-six. With each episode he had severe occipital headache associated with a mononuclear pleocytosis and an increase in CSF protein. He had a neuroepithelial cyst originating from the choroid plexus of the right cerebellomedullary cistern. Spontaneous ruptures of the cyst probably caused recurrent chemical meningitis. A neuroepithelial cyst must be considered in the differential diagnosis of intracranial cystic tumors presenting with aseptic meningitis.

Adult↗
PubMed1991

Numb chin syndrome secondary to Burkitt's cell acute leukemia.

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.

Burkitt Lymphoma↗
PubMed1990

Hereditary pressure-sensitive neuropathy: demonstration of "tomacula" in motor nerve fibers.

By studying intramuscular nerves in 2 patients from 2 families with hereditary pressure-sensitive neuropathy (HPSN), the occurrence of abnormal thickening of myelin sheaths ("tomacula") was for the first time demonstrated in motor nerve fibers. Furthermore, the tomacula were found to line up on certain axons instead of being randomly distributed. These results indicate that the recurrent mononeuropathies of HPSN arise from an underlying asymptomatic motor and sensory polyneuropathy. It is also suggested that some signals emanating from the axons might be related to the formation of tomacula on the basis of the genetically determined myelination disorder.

Adolescent↗
PubMed1990

Pain-related somatosensory evoked potentials in cortical reflex myoclonus.

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.

Adolescent↗
PubMed1990

Cortical tremor: a variant of cortical reflex myoclonus.

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.

Aged↗
PubMed1990

[Treatment of HTLV-I-associated myelopathy with alpha-interferon and high-dose of gamma-globulin].

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.

Adult↗
PubMed1989

Human neurolymphomatosis by adult T-cell leukemia.

We report a case of adult T-cell leukemia presenting with sensorimotor polyneuropathy with persistent severe pain. The patient died without treatment after 4 months. Autopsy showed infiltration of peripheral nerves by leukemia with no involvement of the CNS. This case closely resembles Marek's disease of fowls, a virus-induced T-cell lymphoma associated with neurolymphomatosis.

Humans↗
PubMed1989

[A case of stimulus-sensitive segmental spinal myoclonus].

A 37-year-old-man was admitted to our hospital because of periodic contraction of the right shoulder muscles of approximately one month's duration. He denied any significant history such as trauma or fever. General physical examination was unremarkable. Neurological examination was also unremarkable except for the periodic synchronous myoclonus involving the right sternocleidomastoid, trapezius, deltoid, rhomboid and serratus anterior muscles. X-ray fluoroscopy demonstrated a synchronized rhythmic contraction of the right diaphragm. The myoclonus was considered to be of spinal origin, because those muscles were innervated by the right fourth and fifth cervical spinal segments. Its frequency was approximately 1.2 Hz. The myoclonus disappeared during sleep. It was enhanced by a voluntary contraction of the corresponding muscles, but mental stress such as arithmetic induced no change in the myoclonus. CBC, serum laboratory data including viral antibody titer, and cerebrospinal fluid were all normal. Radiological examination including MRI showed no abnormal finding. EEG as well as somatosensory evoked potentials following median nerve stimulation were normal. Jerk-locked averaging triggered by the myoclonus of the right deltoid muscle showed no pre-myoclonus spike at the scalp electrodes. Clonazepam (1.5-6 mg/day) and phenytoin (200 mg/day) reduced the rhythmicity as well as frequency of the myoclonus, which then became stimulus-sensitive. The reflex myoclonus was induced by tapping anywhere on the body or by electric shock, but not by flash or sound. There was a refractory period of approximately 800 msec. Lack of the stimulus-sensitivity early in the clinical course could be due to this refractory period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[A case of orthostatic tremor in parkinsonism].

A 79-year-old woman presenting with orthostatic tremor (OT) was reported. In addition to OT, neurological examination showed mild dementia, bradykinesia, rigidity of the neck and the upper limbs and positive Babinski reflex on the left. These clinical signs and CT as well as MRI findings suggested vascular parkinsonism as its pathological background. Upon standing with her feet together, she rapidly developed rhythmic repetitive contraction of all leg muscles. The shaking disappeared by walking, sitting, or lying down. The EMG recording revealed 4-Hz tremor which consisted of alternating contraction of anti-gravity muscles and their antagonists. The EMG bursts associated with the tremor were synchronous in corresponding muscles of both legs. OT could be bilaterally reset by unilateral voluntary or passive movement of leg. In the supine position, the tremor was not evoked by voluntary contraction of leg muscles against resistance. As the tremor was aggravated by the administration of haloperidol was suppressed by L-DOPA, it was thought to have the pharmacological basis common to the resting tremor of parkinsonism. Furthermore, we postulated that the postural tonus-regulating system, which is thought to set and maintain the tonus of antigravity muscles for standing upright, might be involved in the generation of the rhythmic discharge pattern (reciprocal bursts in a given leg and synchronized bursts in both legs) of OT.

Aged↗
PubMed1988

Clinical picture of HTLV-I associated myelopathy.

Clinical and electrophysiological findings in 16 consecutive cases of HTLV-I associated myelopathy are reported. Symmetric spastic paraparesis associated with only mild hyperreflexia in the arms, clinical and electrophysiological evidence of moderate posterior column involvement at the thoracic level, urinary frequency and urgency associated with the detrusor-urethral sphincter dyssynergia but without systemic autonomic involvement, and absence of the segmental grey matter involvement, all suggest the presence of diffuse lesions of the white matter predominantly involving the thoracic cord. We conclude that HTLV-I associated myelopathy is a chronic diffuse leukomyelitis predominantly involving the thoracic cord.

Adolescent↗
PubMed1988

Somatosensory and acoustic brain stem reflex myoclonus.

A patient with brain stem reflex myoclonus due to a massive midbrain infarct was studied electrophysiologically. Myoclonic jerks were elicited at variable latencies by tapping anywhere on the body or by acoustic stimuli, and mainly involved flexor muscles of upper extremities. The existence of convergence of somatosensory and acoustic inputs in the brain stem was suggested. This myoclonus seemed to be mediated by a mechanism similar to the spino-bulbo-spinal reflex.

Aged↗
PubMed1988

Multimodality evoked potentials in HTLV-I associated myelopathy.

Multimodality evoked potentials (EPs) consisting of somatosensory EPs (SEPs), visual EPs (VEPs) and brainstem auditory EPs (BAEPs) were studied in 16 cases with HTLV-I associated myelopathy (HAM). Median nerve SEPs were normal in all cases. In posterior tibial nerve SEPs, the potential recorded at the 12th thoracic spinal process was normal in every case but cortical components were significantly prolonged in 10 cases, although five of these showed no sensory impairment. BAEPs were normal in every case whose hearing was intact, but VEPs were abnormal in two cases whose visual acuities were normal. The present results in HAM indicate predominant lesion in the thoracic cord, and might also suggest some subclinical lesion in the visual pathway.

Adult↗
PubMed1988

Treatment of essential tremor with arotinolol.

We investigated the effect of arotinolol, a new peripherally acting beta-adrenergic blocker, in 15 patients with essential tremor. The patients received 30 mg per day of arotinolol for 8 weeks. Accelerometer readings showed a significant reduction in amplitude of postural tremor after treatment. Action tremor also improved to essentially the same degree as postural tremor. The present findings support the view that the therapeutic effect of beta-blockers in essential tremor is mediated by peripheral beta-adrenergic receptors.

Adrenergic beta-Antagonists↗