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Biomedical subjects

G W Kim

Publications and source records attributed to G W Kim.

27 records · Page 2Linked to original sources
PubMed1998

Dopaminergic influences on the P300 abnormality in Parkinson's disease.

This study was designed to evaluate the contribution of central dopaminergic mechanisms to the P300 event-related potential (P300) abnormality in Parkinson's disease. We measured the P300 in 37 non-demented patients with Parkinson's disease (19 de novo and 18 levodopa-treated) and 15 age-matched healthy volunteers. The P300 measurement was repeated in 14 de novo patients, after 6-12 months levodopa therapy. The severity of parkinsonian symptom was assessed using the UPDRS-motor scale. De novo patients showed prolonged P300 latency compared with levodopa-treated patients, as well as healthy volunteers. The levodopa therapy for 6-12 months significantly shortened the P300 latency and reduced the UPDRS-motor examination score in de novo patients. However, the percent changes in the P300 latency were not correlated with those in the UPDRS-motor examination score. These results indicate that the central dopaminergic mechanisms apart from those responsible for motor symptoms, may contribute to the P300 abnormality in Parkinson's disease.

Acoustic Stimulation↗
PubMed1997

Blood flow velocity changes in the middle cerebral artery as an index of the chronicity of hypertension.

This study was designed to demonstrate cerebral hemodynamic changes related to hypertension using transcranial Doppler ultrasonography. We measured the flow velocities and the Gosling pulsatility index of the middle cerebral artery and the internal carotid artery in 94 stroke-free, hypertensive patients and 81 age- and gender-matched healthy controls. Compared with the control subjects, patients with a longer duration (> or = 5 years) of hypertension showed significantly lower flow velocities of the middle cerebral artery and a higher Gosling pulsatility index of the middle cerebral- and the internal carotid artery. These differences were not observed in patients with a shorter duration of hypertension (<5 years). In the patient group, the mean velocity of the middle cerebral artery was significantly and inversely correlated with the duration of hypertension. Decreased flow velocity with increased pulsatility observed in this study suggest that alterations in the small cerebral vessels and arterioles contribute primarily to cerebral hemodynamic changes occurring in long-standing hypertension and also suggest the possible usefulness of transcranial Doppler in monitoring the progression of cerebral atherogenesis related to hypertension.

Adult↗
PubMed1997

Do hematocrit and serum fibrinogen influence transcranial Doppler measurements?

To investigate the effect of hematocrit and serum fibrinogen on transcranial Doppler ultrasound (TCD) measurements, we performed, TCD tests and measured hematocrit and serum fibrinogen concentrations in 112 healthy adult volunteers. The mean velocities of the middle cerebral (r = -.37, p < .0001), internal carotid at siphon (r = -.14, p < .05) and cervical level (r = -.14, p < .05), vertebral (r = -.21, p < .005) and the basilar artery (r = -.33, p < .001) were significantly and inversely correlated with hematocrit, while serum fibrinogen weakly affected the mean velocities of the internal carotid artery. The subjects with low hematocrit (< or = 40%) showed significantly higher mean velocities of the middle cerebral, vertebral and basilar arteries than those with high hematocrit (> 40%). Considering the influence of the subject's age and gender, hematocrit is the strongest factor influencing the velocities of the middle cerebral and the basilar artery. These results suggest that hematocrit is an important variable for TCD measurements of the cerebral blood velocities and should be taken into account in TCD application.

Adult↗
PubMed1996

Vertigo of cerebrovascular origin proven by CT scan or MRI: pitfalls in clinical differentiation from vertigo of aural origin.

To get a better insight into the clinical differentiation between vertigo of cerebrovascular origin and of aural origin, we investigated radiologically proven stroke patients who presented with vertigo as an initial clinical manifestation. Of 154 stroke patients, 30 patients with vertigo (20%) had the relevant lesion, demonstrated with the initial computerized tomographic scan (13 patients) or the follow-up magnetic resonance imaging (MRI) study (17 patients) of the brain. Every lesion was in the vertebrobasilar arterial territory; 19 in the cerebellum, 8 in the pons, and 3 in the medulla oblongata. Although 12 of the 30 patients (40%) presented with vertigo in isolation at the onset of stroke, eight patients (27%) developed additional neurologic abnormalities from four hours to seven days later. Patients with isolated vertigo (13%) had the small lesion exclusively in the cerebellum of the PICA medial branch territory. The most frequent accompanying neurological sign was swaying in the cerebellar and medullary lesion, and dysarthria in the pontine lesion. The direction of nystagmus or swaying did not match the lesion side in some patients. Our findings suggest that cerebellar stroke may commonly manifest isolated vertigo or vertigo with swaying mimicking labyrinthine disorder, particularly at the onset of the disease. MRI study and tests for truncal ataxia and lateropulsion may be crucial for the detection of vertigo of cerebrovascular origin.

Adult↗
PubMed1995

Relationship between the auditory P300 and the procedural memory function in drug-naive patients with Parkinson's disease.

We evaluated and compared procedural memory and auditory P300 event-related potential in age-matched normal controls (n = 15) and drug-naive patients with Parkinson's disease (n = 16). We used Gollin's incomplete picture test for visual procedural memory function and Tower of Hanoi puzzle for visuomotor procedural memory function. The mean latency of P300 was significantly prolonged in the Parkinsonian group than in the controls. In the neuropsychology test, the patients group revealed selective impairment of visuomotor procedural memory against preserved visual procedural memory. In the patients group, the latency of P300 was inversely correlated with performance of visuomotor procedural memory. These results suggest that prolonged auditory P300 event-related potential show the dysfunction of visuomotor procedural memory in the basal ganglia, which appears to be more selectively impaired than visual procedural memory in drug-naive patients with Parkinson's disease.

Event-Related Potentials, P300↗
PubMed1993

Gonadoblastoma and dysgerminoma associated with 46,XY pure gonadal dysgenesis--a case report.

Gonadoblastoma and dysgerminoma developed in a 24-year-old phenotypic female patient with 46,XY pure gonadal dysgenesis. This patient presented with primary amenorrhea. Clinical characteristics showed a typical stigmata of gonadal dysgenesis: primary amenorrhea, sexual infantilism, a small uterus and bilateral streak gonads. A 46,XY karyotype was made by lymphocyte culture. The patient was counseled to undergo a prophylactic bilateral gonadectomy, but she refused. Three years and three months after the initial diagnosis she felt a growing pelvic mass. Bilateral gonadectomy and total hysterectomy were performed. Histological examination revealed gonadoblastoma and dysgerminoma on both gonads. After surgery the patient received radiation therapy and also was started on hormone replacement therapy. Two years and two months after treatment by surgery the patient is well and free of recurrence.

Adult↗
PubMed1991

RETT's syndrome in Korea--report of two cases.

Rett's syndrome(RS) is a progressive neurodegenerative disorder characterized by exclusive occurrence in females, autistic behavior, dementia, gait ataxia, loss of purposeful use of the hands with stereotypic hand movement, and seizures. Initially RS was considered to be very rare; however, recent reports suggest that the prevalence is considerably higher and occurrence is world-wide. Because the pathophysiological process remains unknown, the diagnosis of RS is based mainly on its characteristic clinical features and course. We experienced two cases of RS which, to our knowledge, are the first reported in Korea. It is quite possible that many patients with RS not yet being diagnosed in Korea.

Child↗
PubMed1991

Two cases of mitochondrial myopathy with predominant respiratory dysfunction.

Although it is well known that the respiratory failure is a major cause of death in most patients with chronic neuromuscular disease, predominant respiratory dysfunction without severe involvement of limb muscles is an unusual complication of mitochondrial myopathy in adult age. We experienced two cases of mitochondrial myopathy with severe involvement of respiratory function and only mild involvement of limb muscles. One is a 16 year old female and another is a 22 year old male. The diagnosis is based on morphologic characteristics of "ragged red fibers" under the light microscope and abnormal mitochondrias on the electron microscope in the muscle biopsy.

Adolescent↗