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Biomedical subjects

K Funahashi

Publications and source records attributed to K Funahashi.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Pitfalls in cortical localization by intraoperative recording of cortical somatosensory evoked potentials].

Cortical somatosensory evoked potential (SEP) recordings were made in 11 patients who had lesions located in or near the somatosensory or motor gyri to localize the central sulcus and sensorimotor cortex during neurosurgical operations. Cortical localization was successful in 7 of the 11 patients by recording phase reversal waveforms of N20 and P20 at electrode sites in the hand area on opposite sides of the central sulcus. There were 4 cases in which the cortical localization failed. Locations of craniotomy were far distant from the central sulcus retrospectively in 2 of the 4 patients. Cortical SEPs couldn't be recorded despite probable exposure of the hand area and apparently adequate stimulation and recording conditions in 2 patients who had showed no or low amplitude scalp SEP preoperatively. In one of these 2 patients only low amplitude negative waves were recorded at the cortex which was thought far field potentials originated from subcortical structures. In 2 patients cortical SEP was monitored during the removal of the tumors and was useful to estimate the effects of the operative procedures on the sensorimotor cortex. It is concluded that the localization of cortical functions using cortical SEP is useful for reducing risk associated with intracranial surgery. However, we must be aware that there are some pitfalls in this method.

Adolescent↗
PubMed1992

[A case of parkinsonism induced by an oral contraceptive].

We report a case of parkinsonism induced by long term administration of an oral contraceptive. A 38-year-old woman complained of easily stumbling, démarche à petit pas and fatiguability in her lower extremities since January, 1991. When examined on April 5, 1991, she explained taking an oral contraceptive for 7 years on her doctor's recommendation after two times artificial abortions. Her facial expression was mask-like and body was bent forward with knee joints flexed and arms flexed at elbow joints. She had frozen gait with inactive pendulousness of the arms. We could find her muscle rigidity in both upper and lower extremities, especially in her right side extremities. A brain MRI finding was lacunar infarction which proton density weighted and T2-weighted MR images showed small patches of high-signal intensities in white matter of the bilateral frontal lobes and in left periventricular white matter. Her symptoms improved after stopping administration of the oral contraceptive and starting combination therapy with nicergoline and bromocriptine. She had some leg fatiguability at the onset of her next menstruation in May, but it was much less than her previous condition. When her menstruation terminated, those symptoms disappeared and it was possible to stop the administration of bromocriptine and nicergoline, and her symptoms have improved.

Adult↗
PubMed1992

[Three dimensional display of cerebral vessels using a personal computer].

A new method for a 3-D reconstruction of angiographic cerebral vessels was developed. This system was constructed from inexpensive equipment such as a personal computer, a video camera, a video display, and a digitizer. The input of the vessel images on anteroposterior and lateral angiograms was performed using a video camera with a personal computer and an image processing program (FDM 98-4; Fotoron Co.). These processed images were modified with our original editorial method. This can contribute a lot to the erasing of "non-vessel" images such as skull bone and other noise. It also adds concerning vessels which cannot be clearly taken from angiograms with the video camera. The most beneficial point of the editorial method was to reduce the time consumed in the reconstruction. The spatial points of X-ray discharging boxes against the AP and lateral films were calculated from the length and width of the radiated images of metal bars. These bars were attached to the 3 planes of the lucent box in which the patient's head was inserted to take the angiograms. The 3-D points of the vessels were calculated as follows; one point of a vessel on the lateral image and the spatial point of the X-ray discharging box against the image were linked by a line on which a point moved within a Z range. When the extended line which linked the point and the position of the X-ray discharging box against the AP view crossed the AP image, the Z value of the point was adopted and X and Y values were gained.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Angiography↗
PubMed1989

[Three-dimensional display of structures and lesions in the brainstem using a personal computer].

The method of three-dimensional reconstruction of structures and lesions in the brainstem was developed by using a personal computer to visualize the affected sites in some cranial nuclei and long tracts. Outlines of brainstem structures and lesions were digitalized manually by tracing the atlas of the human brainstem and CT or MR images. Four outlines of the brainstem, the medulla, lower pons, upper pons and midbrain, and the outlines of any parenchymal structures were taken at every point 2 mm in thickness. These were used as the standard visualization of the atlas. The CT and MRI, which show outlines of the lesions, were taken on the vertical planes to the floor of the fourth ventricle, one of which included the fastigium, at every point 3 to 5 mm in thickness. These two kinds of outlines, taken from the atlas and the CT/MRI, were reconstructed three-dimensionally with commercial 3-D software. It took only 20 to 25 minutes for the digitalization and the 3-D reconstruction. Three-dimensional display of small structures, which were difficult to identify on CT or MRI, and lesions would enable the visualization of their anatomical relations and make possible the detection of the affected sites, not only in the axial but in the longitudinal direction. Correspondence between the affected sites on 3-D and the neurophysiological examinations (ABR, SSEP) confirms that our 3-D method is adequate for use in the anatomical diagnosis of affected sites in any small structure in the brainstem.

Brain Diseases↗
PubMed1989

[Effects and indications of spinal cord stimulation on the vegetative syndrome].

The effects of spinal cord stimulation (SCS) on the vegetative syndrome were studied in six patients. Factors affecting the results were mentioned with a view to establishing indications as to whether or not the SCS should be performed. "Persistent vegetative states" were thought to be identical with Ohta's "vegetative syndrome" which consists of eleven signs. Six of these signs--polyphasic cycle of waking and sleeping, urinary incontinence, being bedridden and being tube fed etc--were important criteria of the vegetative syndrome. SCS was thought to be effective if one or more of the 6 signs disappeared after SCS. SCS was performed at level from C2 to C4 with a frequency of 25 to 120 Hz, an intensity of 2.5 to 6 volts, a pulse duration of 0.3 to 0.5 msec. and a duration of 3 to 11 hours per day. Neurological signs, ABR, CT/MRI, EEG and the grade of the vegetative syndrome were estimated before and after SCS. In the course of SCS, 2 of the 6 patients recovered from the vegetative syndrome. Both had a localized lesion in the brain stem without a cerebral lesion on CT/MRI, with bilateral appearance of the fifth peak with prolonged latency and decreased amplitude of main peaks on ABR. The other 4 patients showed little or no improvement. They all had diffuse cerebral atrophy or low density areas on CT and almost normal ABR. One of these patients, who suffered a cerebral contusion leading to transtentorial herniation with unilateral cerebral contusion on CT and unilateral disappearance of the fifth peak on ABR, showed no recovery from the vegetative syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Congenital vertical pendular nystagmus in sisters.

Sisters with congenital vertical nystagmus are described in this report. In these 2 cases, the nystagmus on the electronystagmogram (ENG) showed a pure pendular pattern on forward gaze. Neurological examinations revealed no abnormality except for the nystagmus and visual disturbance. In the elder sister, the ENG showed that the intensity of the nystagmus decreased during eye closure and that there was no response to vertical optokinetic stimulation. We believe that the elder sister is the first case of congenital vertical pendular nystagmus confirmed by neuro-otological and neuro-ophthalmological examinations.

Child↗
PubMed1988

[Three-dimensional correlation between auditory brainstem response and auditory tract in hypertensive pontine hematoma].

A three-dimensional reconstructed display using a microcomputer represents the spatial correlation between the nuclei of auditory tract and pontine hematoma. Stereotaxic evacuation of hematoma was performed on seven cases of pontine hemorrhage. By making a comparison between preoperative and postoperative findings of ABR and this display, we examined the effect of the surgical intervention on ABR findings. ABR was recorded according to the standard way (100 dBSL, 2000 click stimuli). Hematoma was drawn on the Atlas of the Human Brainstem and Cerebellar Nuclei by Farhad Afshar. The data plotted on digitizer was inputted and processed under our computer program that enables the brainstem and hematoma visualized and rotated three-dimensionally at our option. The results were as follows: a) ipsilateral dominance in human auditory tract in terms of the origin of ABR waves, b) delayed latency time of wave II which was supposed to be based on an influence upon the ipsilateral superior olivary nucleus, c) that of wave III upon the ipsilateral lateral lemniscus, d) four cases of them showed an improvement of I-III interpeak latency time, which suggested the decompressive effect on caudal aspect of pons.

Adult↗
PubMed1988

[A study of visual function in congenital nystagmus--mechanism of visual improvement after stereotactic superior colliculectomy].

The clinical features of congenital nystagmus (CN) were studied statistically in 106 cases of CN. The point of the nystagmus at which the patients could best see the targets was detected in some patients. The effects of superior colliculectomy on their visual disturbance and the mechanism will be discussed. The study population comprises 106 patients, 79 males and 27 females, aged from one to 64 (mean 19.4 years). Patients with jerky type classified on ENG were found in 53 cases (50%), pendular type in 39 cases (37%), and mixed type in 14 cases (13%). Patients with jerky type showed significantly good visual acuity (mean 0.69 +/- 0.31, p less than 0.005). They showed significant abnormalities during pregnancy and delivery (p less than 0.01) and had a neutral point (p less than 0.01). Patients with pendular type, on the other hand, showed poor visual acuity (mean 0.26 +/- 0.30) and had significant frequency of family history (p less than 0.05), head tremor (p less than 0.01) and strabismus (p less than 0.01). Thirteen cases (12%) had ocular diseases which involved the retina, cornea and optic nerve. Visual function was elaborated on such parameters of ENG as perception, peak variation and plateau time. Perception, which means the ability to detect the dim flashes during the appearance of the nystagmus, was manifested by pushing a button when patients could detect flashes presented at random on the screen. At the turning point from the quick phase to the slow phase, the detection was executed most successfully. It is thought that in CN, a target is usually gazed upon at a point, changing the direction from the quick phase to the slow phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

[Primary T-cell type lymphoma of the central nervous system: a case report].

A case of T cell type primary lymphoma of the CNS is reported. A 50-year-old man was admitted because of speech and memory disturbance and dyscalculia. He had suffered from uveitis of both eyes two years before admission. Neurological examination revealed motor aphasia, finger agnosia, dyscalculia and memory disturbance. CT scan showed a mass lesion which was enhanced irregularly by the contrast medium in the left temporoparietal region. CAG confirmed the presence of a left temporoparietal avascular mass. Total removal of the tumor was performed through the left temporoparietal craniotomy. Histopathological diagnosis of the tumor was malignant lymphoma (diffuse, large cell type). Immunological study with tumor cells in the cerebrospinal fluid revealed that the tumor was T cell type malignant lymphoma. After postoperative whole CNS irradiation and intrathecal methotrexate injection, his preoperative symptoms disappeared. No evidence of the tumor recurrence is seen under CT scan one year and two months after the tumor resection. Relationship between the cell type of the tumor and CT findings is discussed.

Brain Neoplasms↗
PubMed1985

Chronic subdural hematoma after open heart surgery.

Three cases of chronic subdural hematoma after open heart surgery are reported. In all cases, computed tomography scans revealed subdural accumulations of high density after cardiac surgery. The high-density areas changed into isodensity or low density with mass effect within 2 or 3 weeks. Anticoagulant (heparin) and a tearing of bridging veins after a rapid change of the brain volume by administration of mannitol can be a cause of chronic subdural hematoma. Forty-five to 60 mL of liquefied hematoma was aspirated and the outer membrane of the hematoma cavity was recognized by a trepanation.

Adult↗
PubMed1983

Moyamoya disease associated with intracranial aneurysms.

A case of moyamoya disease associated with multiple intracranial aneurysms is reported. The aneurysms were located at the bifurcation of the basilar artery and at the precommunicating segment of the right posterior-cerebral artery. They were found to be unruptured and clipped successfully through a right frontotemporal craniotomy. Outcome of the operation was satisfactory. We propose the operative indication for these cases on the basis of operative and radiological findings, and also discuss characteristic aspects of this disease.

Adult↗
PubMed1982

[Traumatic aneurysm of the posterior inferior cerebellar artery (author's transl)].

The incidence of traumatic intracranial aneurysms are rare. In review of literature, only six cases of traumatic aneurysms in posterior fossa are reported. The patient, 15-year-old girl, was admitted on Dec. 18th, 1979, presented with unconsciousness after a traffic accident. She was developed impaired consciousness and left hemiparesis with right hemotympanum and nasal bleeding. Skull film showed an occipital linear fracture and a laminal fracture of the atlas. CT scan demonstrated traumatic subarachnoid, intraventricular hemorrhage and pneumocephalus. After accident, she regained consciousness with conservative therapy, but she deteriorated on the 10th hospitalized day. On the 17th day, lumbar puncture and CT scan revealed recurrent subarachnoid and intraventricular hemorrhage. The saccular aneurysm on the lateral medullary segment of the right posterior inferior cerebellar artery was obtained by cerebral angiogram on the 35th day. The configuration and size of the aneurysm was easily demonstrated by CT scans and cerebral angigrams. On the 43rd day, the clipping of the common trunk of the right posterior inferior cerebellar artery was employed. Her postoperative course was uneventful and she was discharged on the 97th day in good condition. This aneurysm was suggested to be induced by severe head injury with clinical ad operative findings. With the introduction of CT scan, CT scan is more available diagnostic modality than cerebral angiography in the follow up study with severe head injuries. And in the absence of pathological CT scan findings, suspicion of traumatic cerebrovascular impairments such as aneurysm should be paid. As the conservative management of traumatic intracranial aneurysms carries high mortality rate up to 30-50%, the prompt diagnosis and direct surgical intervention are recommended.

Adolescent↗