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Biomedical subjects

S Namba

Publications and source records attributed to S Namba.

At least 73 records · Page 4Linked to original sources
PubMed1987

[Clinical study of late onset Chiari type I malformation].

Eight cases, 5 males and 3 females, of Chiari type 1 malformation aged from 9 to 51 years (mean 33.3 years) were analysed. The average age of the onset of symptoms was 29.6 years, between 7 and 44 years, and that from the onset of symptoms to the presentation to the hospital was 3.3 years ranged from 1 month to 16 years. Pain (87%) in the head or in the cervical region was the most common symptoms, the former was 5 cases and the latter was 2. The next common symptoms were unsteadiness and gait disturbance (50%). Weakness of one or more limbs was the complaints of 3 (38%) of the patients, and sensory impairment was 38%. Other symptoms included stiffness of the neck and shoulder, limitation of the neck movement, abnormal head posture, rectourinary incontinence and so on. In physical examination, foramen magnum compression signs (63%) and cerebellar signs (63% were most common and lower cranial nerve palsy (38%) and intracranial hypertension (25%) were included. Abnormalities of the skull and cervical spine were common on X-ray films. The were cervical fusion or occipitalization and basilar impression. On the angiograms, descended PICA was visualized in all cases. CT metrizamide myelography was performed in 2 cases and MRI was done in 1 case. They could clearly demonstrate the descended tonsils and were found to be the most reliable radiographic examination in the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Opiate-antagonist reversal of neurological deficits--experimental and clinical studies.

The proximal left M1 and the common trunk of A2 were clipped in 12 adult dogs. Naloxone was injected after placing the clips onto 6 dogs. Neither the systemic blood pressure nor the local cerebral blood flow were influenced by naloxone. In another group of 6 dogs with chronic right hemiplegia, naloxone proved passably effective in improving the hemiplegia. Eight patients with neurological deficits of various etiologies were administered levallorphan. The improvement in motor performance and/or elevation of mental activity was observed more or less in all but 2 of the patients. It was considered that the effect of opiate antagonists is based partially on the facilitation of synaptic transmission exaggerated by the arousal response.

Adult↗
PubMed1986

[Long-term follow-up study of spasmodic torticollis].

Since 1958, 61 patients with spasmodic torticollis, 46 of whom did not develop other kinds of involuntary movements, have been experienced in our neurosurgical clinic. The course of these 46 patients was followed for more than one year. The retrospective analysis revealed 25 patients were treated conservatively, and 21 patients were treated surgically. Surgical treatment consisted of stereotactic ventrolateral thalamotomy in 19 patients, and Olivecrona's operation in the other 2. The long-term outcome of conservative therapy was compared to that of surgical therapy. One patient with severe retrocollis with horizontal components was treated successfully but transiently by implantation of stimulating electrodes in the cervical epidural spinal cord. The peak incidence of the onset of the disease was in the fourth decade; however, the time of onset ranged from 7 to 55 years of age. The period from disease onset to the final evaluation in the follow-up was 9.3 years (mean) in the conservative group, and 8.5 years in the surgically treated group (no significant difference). There were no significant differences between the groups in the interval from the time of disease onset to the initial evaluation in our clinic, stage determined at evaluation, and follow-up period after the initial evaluation. Of the 25 conservatively treated patients, symptoms and signs remained unchanged in 8, deteriorated in one, but improved significantly in most of the remaining patients. Many of the surgically treated patients showed improvement one week after surgery, but the long-term outcome was not significantly better than that of the conservatively treated patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Dissociative sensory disturbance after removal of an arteriovenous malformation in the posterior thalamic region].

A 34-year-old male developed consciousness disturbance; semicoma, on December 15, 1984, and diagnosed as a thalamic hemorrhage perforating into the ventricular system after a computed tomographical (CT) examination. Angiography revealed an arteriovenous malformation (AVM) in the right posterior thalamic region, which was fed by a posteromedial choroidal artery. He was transferred to our neurosurgical clinic on February 18, 1985. On admission, he was alert, however, disorientation and slight mental retardation were seen as well as Parinaud's sign. Mild left hemiparesis was also detected with equivocal hypesthesia on the left lower limb. The AVM was subtotally removed on March, 12, via transventricular approach after right parietooccipital craniotomy. Consciousness disturbance (drowsy) and left hemiplegia developed after the operation, however, these deteriorations were transient, recovering to the preoperative or better status by 2 weeks after the operation. Postoperative repetitive examinations of the sensory perceptibility of various modalities revealed remarkable disturbance or complete loss of perception in joint and vibration senses (0-3/10 compared to the healthy left side). Touch sensation was also severely deteriorated (0-3/10) on the affected extremities. The disturbances in these modalities of the sensation did not show any trend to improve until the time of discharge on 57th postoperative day. On the other hand, pain and temperature sensations were less remarkably disturbed (5-8/10), and with tendency of gradual improvement. Estimation of the range of lesion by the CT scan with projecting on the Schaltenbrand & Bailey's atlas revealed that the nucleus ventralis caudalis, centre-median nucleus and pulvinar thalami were involved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Diencephalic syndrome of emaciation (Russell's syndrome). Long-term survival.

Three cases of diencephalic syndrome are reported. Two of them, which have been observed postoperatively for more than 7 years, showed typical clinical and endocrinologic features at the time of their first admission, but showed mass signs uncharacteristic of diencephalic syndrome after recurrence of the tumor. Recent data showed a normal baseline for plasma growth hormone but abnormalities in provocation tests. The significance of age in the manifestation of the syndrome is briefly discussed, especially in relation to the tendency toward normalization in the growth hormone level at a later age.

Astrocytoma↗
PubMed1985

An experimental model of deafferented pain in the cat.

Deafferentation hyperactivity, produced unilaterally in the neurons of the subnucleus caudalis of the spinal trigeminal nucleus (STNcd) in cats by left Gasserian ganglionectomy, was studied neurochemically and electrophysiologically. Analysis of neuronal activities on both sides of the STNcd was done 11-63 days after the denervation. On the denervated side, 37 (57%) of the 65 neurons identified showed deafferentation hyperactivity. Continuous and spontaneous firing of these hyperactive neurons were inhibited neither by the intraventricular administration of morphine or enkephalinamide nor by the electrical stimulation of periaqueductal gray. In contrast, the facilitation of the pain perceptive neuronal activities in the STNcd of the nondenervated side was remarkably inhibited, both by the administration of the same drugs and by periaqueductal gray stimulation. The deafferentation hyperactivity produced in this experiment in the STNcd of the denervated side might have a close physiological relationship to the deafferented pain of clinical patients.

Afferent Pathways↗
PubMed1985

Sensory and motor responses to deep brain stimulation. Correlation with anatomical structures.

Motor and sensory responses induced by trial stimulation were examined before stereotaxically implanting a permanent stimulating electrode for pain relief in 11 patients with intractable pain of central origin. The total number of points eliciting a response when stimulated was 70. The points of stimulation were determined as exactly as possible from Schaltenbrand and Bailey's Atlas. Motor responses were detected upon stimulating 21 points, the majority of which were in the posterior third of the posterior limb of the internal capsule (IC). Stimulation of these 21 points was accompanied by pain relief in only two points (10%). Warm (22) or cool sensations (three) were provoked in the most posteromedial portion of the posterior limb of the IC, nucleus reticularis pulvinaris, and area triangularis, and seven (28%) of these 25 sensations were accompanied by pain relief. A burning sensation was found upon stimulation of 12 points, with stimulation in the mesencephalic lateral tegmental field eliciting the most severe burning pain. A tingling sensation was elicited at 12 points, in a distribution similar to that of the warm sensation. Five (42%) of these 12 points provided pain relief. The best stimulating point for pain relief is not in the center of the posterior limb of the IC, directly lateral to the posterior commissure, but rather in its most posteromedial part; that is, at the nucleus reticularis pulvinaris or area triangularis.

Adult↗
PubMed1985

[beta-Endorphin and monoamine metabolite concentrations in patients with intractable pain--changes before and after deep brain or spinal dorsal column stimulation].

Baseline concentrations of beta-endorphin (beta-EP) and monoamine metabolites (MHPG: 3-methoxy-4-hydroxy-phenylglycol, HVA: homovanillic acid, 5-HIAA: 5-hydroxyindoleacetic acid) in lumbar CSF (LCSF) and ventricular CSF (VCSF) were measured in 18 patients with intractable pain; 10 with deafferented pain and 8 with peripheral pain. Control values were obtained from 37 individuals of various ages. Changes in the concentrations of these substances were determined before and after giving stimulations (2-5 V, 0.2-0.5 msec, 40-50 Hz, 20-sec duration) to 6 patients through electrodes implanted in deep brain structures (DBS; posterior limb of the internal capsule in 5 patients and rostral mesencephalic lemniscus medialis in one patient), and to 2 other patients through electrodes implanted in the spinal dorsal column (DCS). The control value of beta-EP in LCSF was 57.6 +/- 24.7 pg/ml, which was not significantly different from that of VCSF. Great variation in the individual control LCSF beta-EP concentrations was found, but it was not related to differences in age. The mean baseline LCSF beta-EP concentration was significantly higher (p less than 0.05) than the control in the patients with deaffernted pain before stimulation. One of the monoamine-metabolites, MHPG, showed higher level in the patients with peripheral pain (p less than 0.01). The LCSF beta-EP concentration was not affected by deep brain stimulation, but was increased by dorsal column stimulation. In one patient with excellent pain relief by stimulation of the posterior limb of the internal capsule, the LCSF HVA and 5-HIAA concentrations were conspicuously increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Role of the lemniscal system in pain modulation--a consideration based on clinical experience].

Ten patients with intractable pain of central origin were operated on for pain relief by implanting the chronic stimulating electrode (Medtronic Co.) in the posterior limb of the internal capsule, thalamic sensory nuclei or mesencephalic lemniscus medialis, and the results were briefly described. Localization of the lesion demonstrated by CT was projected on the Schaltenbrand & Bailey's atlas in each of these patients and the deep brain structure involved was identified. The lesions were located mainly in the posterolateral thalamus including posteromedial part of the internal capsule (thalamic pain), however, they were located outside of the thalamus in some cases (suprathalamic pain). Two particular patients were described in detail because clinical courses, especially operative results were esteemed to be suggestive of an important role of lemniscal system in pain modulation. A 48-year-old man (Case 7) developed severe spontaneous burning pain on the right half of the body after extensive putaminal hemorrhage. Stimulation of the posterior limb of the internal capsule or of the thalamic sensory relay nuclei elicited no pain relief. Consequently a lesion was stereotaxically made in the most medial portion of the lemniscus medialis of the rostral mesencephalon. This operative procedure provoked previously unrecognized significant dysesthesia and hyperpathia predominantly of the extremities as well as aggravation of hypesthesia and hypalgesia. The second patient (Case 8) was a 44-year-old man who developed dysesthesia, hyperpathia and spontaneous pain of the left hand and face after hemorrhage in the right sensory cortex. Stimulation of the mesencephalic lemniscus medialis of the right side elicited comfortable warm sensation in contralateral upper half of the body including hand, fingers and face with simultaneous diminution of pain. These two cases were suggestive of the role of lemniscus medialis in pain modulation. Blockade of the lemniscus medialis elicited, and its facilitation inhibited the pain. Lemniscal and extralemniscal (spinothalamic) system have been proven to be intermingled in the thalamic and suprathalamic levels. Though both of the systems might be involved in the manifestation of central pain including our present ten cases, it was discussed and postulated that the facilitation of the lemniscal system might inhibit the activity of spinothalamic system, thus resulting in pain relief.

Adult↗
PubMed1985

[Spontaneous angiographical disappearance of an unruptured giant aneurysm of the basilar top demonstrated by a sequential series of angiograms. A case report].

One of the case of the angiographically disappeared giant aneurysm is reported, which was arising from the top of the basilar artery. A 52-year-old man was admitted in April, 1978. He had developed a recent memory disturbance, tremor in the both upper extremities, the rigidity of the four extremities, an ataxic gait and urinary incontinence. Enhanced CT scan on admission demonstrated a large oval mass in the suprasellar region indenting nearly total third ventricle. Bilateral lateral ventricles were significantly dilated. The initial vertebral angiogram shortly after the admission revealed an oval-shaped aneurysm, 27 mm in the longest diameter, arising from the top of the basilar artery. The aneurysm was considered to be inaccessible due to its anatomical location and size. A ventriculoperitoneal shunt was placed, which alleviated clinical symptoms and signs immediately. However, a vertebral angiogram 1 year following the initial angiogram showed significant enlargement of the aneurysm, in spite of hypotensive and coagulant drugs which had been administered, then the administration of hypotensive drugs was ceased. Ventriculo-peritoneal shunt was replaced by ventriculo-atrial shunt in Sep. 1980. Left vertebral angiogram in May, 1981, 3 years after the initial angiogram, demonstrated the aneurysm had completely disappeared. He has been followed-up by the repetitive angiography up to the present, which proved the aneurysm has not reappeared. The occurrence of a spontaneous angiographical disappearance of an intracranial aneurysm is relatively uncommon, especially of a giant aneurysm. A rare case of spontaneous angiographical disappearance of a giant aneurysm was presented in this report.(ABSTRACT TRUNCATED AT 250 WORDS)

Basilar Artery↗
PubMed1984

Inhibition of nociceptive neurons by internal capsule stimulation.

The mechanism of pain relief by internal capsule (IC) stimulation was investigated in 32 adult cats. Nociceptive neuronal activity of the nucleus ventralis posteromedialis (VPM), responding to contralateral pulp stimulation, was suppressed by IC stimulation to a greater extent than activity in the posterior nuclear group (PO) or centre-median nucleus. On the contrary, suppression of neuronal firing by intraventricular morphine-HCl predominated in PO neurons. These results suggest that pain relief by IC stimulation may be mediated through inhibitory effects on nociceptive neurons of the thalamic sensory relay nuclei.

Analgesia↗
PubMed1984

Electrical stimulation of the posterior limb of the internal capsule for treatment of thalamic pain.

Electrical stimulation of the posterior limb of the internal capsule was performed in 7 patients with thalamic pain who had developed dysesthesia, hyperpathia and/or spontaneous burning pain. Ramped bipolar stimulation elicited sensory responses, such as warm or comfortable sensation. Follow-up from 9 months to 2 years and 7 months showed that 3 patients had a good result, two had fair and the remaining two had poor results. No serious side effects were seen. The mechanism of pain relief by the internal capsule stimulation is discussed.

Afferent Pathways↗
PubMed1984

[Diencephalic syndrome--report of three cases].

Three cases of diencephalic syndrome, associated with brain tumors, are reported in this paper. Case 1. A 2-2/12-year old boy was initially admitted to our hospital because of failure to thrive which began at the age of three months. Physical examination revealed emaciation (weight, 7.8 kg), irritability and pallor without anemia. Horizontal nystagmus was seen. Laboratory studies were normal except for abnormally high plasma growth hormone (p-GH) which was incompletely suppressed by hyperglycemia (induced by glucose) and was not elevated by hypoglycemia (induced by insulin). A low grade astrocytoma of the optic nerve compression the hypothalamus was partially removed. After the operation followed by irradiation, p-GH returned to normal both in its basal level and in its reaction to insulin loading, then his gain of weight was accelerated. He was readmitted, however, at the age of 6 8/12 years with headache and vomiting. Since subtotal removal of the recurrent tumor and irradiation, preoperative symptoms have disappeared up to the present (7 9/12 years old). Case 2. A 3-9/12-year old girl was initially admitted because of failure to thrive since the age of 2 years. Examination on admission revealed emaciation (10.5 kg), irritability and right hemiparesis. Laboratory studies were normal except for high serum cholesterol (290 mg/dl). (p-HG was not measured) The patient had been well after the subtotal removal of the hypothalamic astrocytoma except occasional headache until the age of 6 years. She was readmitted at the age of 9 years with progressive emaciation.(ABSTRACT TRUNCATED AT 250 WORDS)

Astrocytoma↗