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Biomedical subjects

N Komai

Publications and source records attributed to N Komai.

At least 37 records · Page 2Linked to original sources
PubMed1996

Transcortical mixed aphasia with left frontoparietal lesions.

We present a case of transcortical mixed aphasia following a left frontoparietal infarct caused by vasospasm after subarachnoid haemorrhage. Although CT showed low-density areas in the left frontal lobe and basal ganglia, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere, except for the left perisylvian speech areas. Hence, transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas due to disconnection from surrounding areas.

Aphasia↗
PubMed1996

Preoperative embolization of meningiomas fed by ophthalmic branch arteries.

BACKGROUND: The efficacy of preoperative embolization for hypervascular meningiomas mainly fed by the branches of the ophthalmic arteries was examined. CASES AND METHODS: Five hypervascular meningiomas mainly fed by the branches of the ophthalmic arteries, four posterior ethmoidal arteries, one anterior falx artery, and one recurrent middle meningeal artery were embolized with Gel-foam powder, polyvinyl alcohol (PVA) particles, and/or microcoils as a preoperative treatment using a microcatheter. RESULTS: Catheterization of the ophthalmic and tumor feeding artery was possible and feeding arteries and lesion embolization were effective to reduce the bleeding during surgery in all cases. In three cases, visual acuity and visual field were preserved. However, in one case, visual acuity and visual field defect appeared due to the migration of Gelfoam powder (Upjohn, Kalamazoo, MI) into the retinal artery. In another case, the retinal artery was embolized with the feeding arteries since the patient was already blind. CONCLUSION: Embolization of hypervascular meningioma feeding vessels arising from the ophthalmic artery is possible and effective with preservation of vision, if embolic agents are injected gently enough not to reflux into the central retinal artery.

Adult↗
PubMed1996

[A case of amnesic syndrome caused by hematoma in the left anterior medial thalamus].

We reported a case of amnestic syndrome caused by a hematoma in the left thalamus. The case was that of a 68-year-old, right-handed man who suddenly showed amnestic syndrome. He had neither motor paresis nor sensory disturbance. Clinical examination showed he had disorientation, anterograde amnesia and mild retrograde amnesia. Immediate recall and remote memory were intact, but recent memory was severely impaired. CT scan revealed a high density area in the anterior medial part of the left thalamus. We concluded that amnesia in this patient was caused by fasciculus mamillothalamicus damage because of a hematoma during thalamic hemorrhage.

Aged↗
PubMed1996

[Super selective amytal test for functional evaluation of the brain--a less invasive functional test].

In the neurosurgical field, it is very important to evaluate localized function of the affected region preoperatively. In order to investigate lateralized and localized brain function, we have developed an alternative to the original Wada test, and refer to it as the super selective amytal test (SSAT). We performed super selective catheterization of the target artery after conventional carotid angiography, injected Amytal (amobarbital, 30-100 mg) through a micro-catheter, and identified potential local function. In ten cases, including AVM, aneurysm, and brain tumor, we investigated localized function of the affected site preoperatively by SSAT, and chose our treatment based on the results of this test. There was a good correlation between the results of the SSAT and the results of surgery in every case. There were no prolonged neurological complications of this test. Evaluation of the results of the SSAT should be interpreted under precise DSA control, since blood flow in the brain differ among individuals. This test may contribute to our knowledge of localized function in the cerebral cortex and deep brain areas in neurosurgical patients.

Adult↗
PubMed1995

Unilateral spatial neglect due to a haemorrhagic contusion in the right frontal lobe.

We report two cases of unilateral spatial neglect associated with an isolated right frontal lobe lesion. Case 1 was a 59-year-old, right-handed man, who developed a left hemiplegia, disorientation, and frontal lobe neglect associated with a haemorrhagic contusion following a head injury. Case 2 was a 55-year-old, right-handed man, who also developed disorientation and frontal lobe neglect secondary to a haemorrhagic contusion following a head injury. 99mTc HM-PAO SPECT revealed an isolated reduction in the regional cerebral blood flow (CBF) around the haematoma in the frontal lobe; blood flow to remaining parts of the brain was normal. Damage to the right frontal lobes of these patients was confirmed as being the cause of the unilateral spatial neglect in accordance with the results of CBF studies.

Attention↗
PubMed1995

Transplantation of cultured sympathetic ganglionic neurons into parkinsonian rat brain: survival and function of graft.

The superior cervical ganglia (SCG) of newborn rats, which had been cultured as explants for varying periods of time, were transplanted into the striatum of rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal dopamine pathway to examine the survival and functional properties of the sympathetic neurons maintained in long-term culture prior to grafting. In the rats given the SCG cultured in vitro for 2 weeks, apomorphine-induced rotational behaviour was satisfactory reduced. The rats receiving the SCG from 4-week-old cultures showed only modest behavioural changes. The grafting of the SCG cultured for 6 weeks in vitro did not affect the rotational behaviour. These behavioural data corresponded with the histological assessment of the graft survival by use of catecholamine histofluorescence. The present results suggest the critical time period in vitro which might allow the cultured sympathetic neurons to be successfully grafted.

Animals↗
PubMed1995

[The effect on higher cortical dysfunction of percutaneous transluminal angioplasty for internal carotid artery stenosis].

Seven patients with internal carotid artery (ICA) stenosis with higher cortical dysfunction due to hemodynamic ischemia were treated by percutaneous transluminal angioplasty (PTA). The patients ranged from 49 to 71 years of age, and included five males and two females. Neuropsychological tests were evaluated before and after PTA. Higher cortical dysfunction improved in all cases after PTA. It is concluded that PTA is effective to improve higher cortical dysfunction in patients who have ICA stenosis associated with hemodynamic compromise, if the ICA is satisfactorily dilated.

Aged↗
PubMed1995

[A case of spinal dural arteriovenous fistula associated with normal pressure hydrocephalus].

A 62-year-old male presented with urinary incontinence, gait disturbance and dementia for 6 months. Neurological examination revealed severe paraparesis (1/5), sensory disturbance below Th10, neurogenic bladder and absence of patellar and achilles tendon reflexes. CT scan showed mild brain atrophy and symmetric ventriculomegaly with periventricular lucency. Magnetic resonance imaging (MRI) showed a linear flow void lesion on the dorsal surface on the back of his swollen lower spinal cord. Myelography showed a filling defect and flow disturbance of contrast medium in lower thoracic levels, suggesting the presence of adhesive arachnoiditis. Spinal angiography demonstrated a fistula formation between dural branches of bilateral L4 lumbar arteries and ventral spinal and radicular veins on the surface of the dura mater of L4/5 levels. Considering his past history of repeated lumbar puncture for tuberculous meningitis at the age of 22 years, a diagnosis of acquired spinal dural arteriovenous fistula probably due to repeated lumbar puncture was made. Fistulas were embolized with N-butyl cyanoacrylate. And normal pressure hydrocephalus was treated by ventriculoperitoneal shunt. Follow-up CT scans showed a decrease of the size of the ventricular system. Etiology of acquired spinal arteriovenous fistula has been reported. In the case, repeated lumbar puncture may be a possible cause of arteriovenous fistula in the lower spinal dura mater. However, the reason why it took so long to form a fistula after the lumbar puncture remains to be elucidated. We suggest that an increased protein concentration due to disturbance of cerebrospinal fluid flow might be a cause of normal pressure hydrocephalus (NPH).

Arteriovenous Fistula↗
PubMed1995

[Effects on cognitive function and activities of daily living after stereotactic thalamotomy for Parkinson's disease].

Stereotactic thalamotomy was performed in ten patients with Parkinson's disease for the suppression of their tremor. After VL-thalamotomy, contralateral tremor and rigidity disappeared or was significantly reduced. Activities of daily living (ADL) measured by functional independence measure and Parkinson's disability score were improved postoperatively in all patients. There was significant improvement in anxiety index. However, other neuropsychological tests showed no significant change postoperatively. ADL improved after thalamotomy. It is concluded that stereotactic VL-thalamotomy is a useful treatment which improves ADL without cognitive dysfunction.

Activities of Daily Living↗
PubMed1995

[Identification of motor area by transcranial magnetic stimulation using an "eight-figure" coil in patients with motor paralysis].

In patients with motor paralysis, we tried to identify the functional motor area by transcranial magnetic stimulation using an "eight-figure" coil designed by Ueno. Motor evoked potentials (MEPs) were recorded in 7 patients from 50 to 64 years old, and in 5 normal volunteers 26 to 45 years old. They were stimulated at 49 points over an unilateral hand motor area, and at 21 points over a foot motor area, and surface MEPs were recorded on their contralateral thenar muscle and abductor hallucis brevis muscle. In normal volunteers, the optimal eddy current for stimulating the hand motor area was directed anteriorly parallel to the midline, and for stimulating the foot motor area, it was postero-laterally directed with an angle of 45 degrees towards the midline. MEPs could be induced at their muscle contractions during which their thumbs and middle fingers softly touched each other, and their halluxes slightly flexed. In five patients two kinds of amplitude mappings reconstructed from MEPs were obtained at rest or at muscle contraction. A line connecting these two peaks on an amplitude mapping was regarded as an "MEP-motor area". A geographical difference between the MEP-motor area and MRI-motor area (identified by an MRI surface image) was studied at muscle contraction and at rest. In normal subjects the sites of the MEP-motor area and of the MRI-motor area coincided, whereas, in patients with space-occupying lesions near the central sulcus, the MEP-motor areas were located 1 to 2cm posterior to MRI-motor areas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Stenotic kinking of the cavernous internal carotid artery with a giant intra-cavernous aneurysm: case report.

We report a giant aneurysm of the cavernous internal carotid artery with proximal internal carotid stenosis. The stenosis showed two typical features: a kink at the stenosis and location at the exit from the carotid canal. We believe that the cavernous portion of the internal carotid artery is compressed medially by the giant aneurysm and a kink occurs at the point where the artery leaves the bony carotid canal.

Aneurysm↗
PubMed1994

Tissue plasminogen activator thrombolysis and transluminal angioplasty in the treatment of basilar artery thrombosis: case report.

A 61-year-old man with basilar artery thrombotic occlusion was successfully treated by a combination of local infusion of tissue plasminogen activator (t-PA) followed by percutaneous transluminal angioplasty (PTA). t-PA superselective infusion combined with the mechanical destruction of the clot by the guide wire was effective for recanalization. A Stealth dilation catheter, with a 2.5-mm balloon diameter and 10-mm length, was used for PTA. A balloon inflation time of 60 seconds with 4 atmospheres of pressure was delivered for successful dilation of the basilar artery. It was confirmed to be widely patent on follow-up angiography 40 days after the combined procedure with no further ischemic attacks apparent on clinical examination at 6 months.

Angioplasty, Balloon↗
PubMed1994

Cerebral pial arterial innervation with special reference to GABAergic innervation.

Glutamic acid decarboxylase (GAD)-immunoreactive (I) nerve fibers were observed to run parallel to other autonomic nerve fibers, especially vasoactive intestinal polypeptide (VIP)- and calcitonin gene-related peptide (CGRP)-I nerve fibers at the light microscopic level. At the ultrastructural level, GAD-immunoreactivities co-localized with CGRP immunoreactivities in nerve terminals, but not with choline acetyltransferase, VIP, tyrosine hydroxylase and neuropeptide Y immunoreactivities. GAD immunoreactivities were observed in the trigeminal ganglion, some of which were co-localized with CGRP-immunoreactivities. In the proximal portion of the internal carotid artery, GAD-I adventitial ganglion cells were observed and some were also immunoreactive for CGRP. These results strongly suggest that the origin of GABAergic innervation of the major cerebral pial arteries of the cat is mainly in the trigeminal ganglion, and partly in the adventitial ganglia of the internal carotid artery.

Animals↗
PubMed1994

Regeneration of norepinephrine-containing fibers in occipital cortex of adult cats.

Regeneration of norepinephrine (NE)-containing nerve fibers in occipital cortex of adult cats was studied using morphological and biochemical methods. Initially, degeneration of cortical NE fibers was induced by direct infusion of 6-hydroxydopamine (6-OHDA) for a week. Cortical reinnervation by NE fibers continuously proceeded throughout 52 weeks, the longest survival period studied, after stopping 6-OHDA infusion. The rate of the reinnervation was slower in mature cortex than that obtained earlier in immature cortex. The present results indicate that the regenerative ability of the central NE neurons is universal, not limited to the immature brain. It is implied that the central NE neurons are equipped with a transmitter-specific repair mechanism throughout life.

Animals↗
PubMed1994

Unilateral spatial neglect due to right frontal lobe haematoma.

Two patients with unilateral spatial neglect caused by right frontal lobe lesions underwent cerebral blood flow studies. A 54-year-old, right-handed woman developed left hemiplegia and frontal lobe neglect associated with cerebral haemorrhage after surgical excision of a frontal tumour. A 66-year-old, right-handed woman developed a haemorrhage in the right frontal lobe caused by rupture of an aneurysm. This was followed by left hemiplegia and frontal lobe neglect. In both cases, 123I-iodoamphetamine single photon emission CT disclosed a reduction in regional cerebral blood flow localised along the circumference of the haematoma in the frontal lobe, but did not reveal any lesions in the parieto-occipital junction. These findings suggest that, in these two cases, the frontal lobe neglect was caused by lesions confined to the frontal lobe.

Cerebral Hemorrhage↗
PubMed1994

Autologous transplantation of the cervical sympathetic ganglion into the parkinsonian brain: case report.

The authors have reported a clinical trial of an autologous cervical sympathetic ganglion transplanted into the brain of a parkinsonian patient. A 45-year-old woman presented with bradykinesia and a gait disturbance for 8 years under L-dopa treatment. The patient underwent stereotactic transplantation of the right stellate ganglion into the right putamen. She showed marked amelioration of bradykinesia and gait disturbance 1 month after the operation, and she was able to conduct her activities of daily living without requiring L-dopa administration. The patient continued to improve gradually until 3 months after the operation. Two years after surgery, the patient functions independently as a housewife. The right hand tremor, however, became slightly worse after the operation, but it was transient. The patient developed a permanent right-sided Horner's syndrome after resection of the cervical sympathetic ganglion. Taken together with our previous data obtained from animal experiments, this case suggests that the autologous cervical sympathetic ganglion can be donor tissue for neural transplantation in Parkinson's disease.

Activities of Daily Living↗
PubMed1994

Pretreatment with interleukin-1 enhances survival of sympathetic ganglionic neuron grafts.

The effects of pretreatment with interleukin-1 (IL-1) on neurite growth and cell survival of rat superior cervical ganglion (SCG) explants were examined. Neonate rat SCG explants were cultured with serum-containing growth media. Pretreatment with IL-1 beta (30 U/ml) for 3 hours stimulated neurite outgrowth of the SCG explant, which was inhibited by the addition of anti-nerve growth factor (NGF) antibody to the growth medium. Adult rat autologous SCG with the same pretreatment and non-treated ganglia were transplanted into the lateral ventricle. Histological evaluation of the grafts 2 weeks after transplantation revealed that the pretreated SCG cells survived better. Pretreatment with IL-1 may achieve the NGF-mediated neurotrophic effect in sympathetic ganglionic neurons resulting in enhanced graft survival.

Animals↗