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K Huh

Publications and source records attributed to K Huh.

65 records · Page 4Linked to original sources
PubMed1990

Long-latency evoked potentials during aura of temporal lobe origin.

Long-latency evoked potentials recorded from scalp or scalp/sphenoidal electrodes have been shown to have diminished amplitude and power during interictal recordings on the side ipsilateral to an unilateral mesial temporal lobe (MTL) focus. We now report recordings of long-latency evoked potentials both during a prolonged aura and also on two seizure-free days. P3 amplitude and sphenoidal evoked potential (SpEP) spectral power in the scalp/sphenoidal channels were less, ipsilateral to the MTL focus. During the aura, the SpEPs had reduced power and reduced amplitude. However, the amplitude of the N2 component for the target averages in the CZ-A1A2 channel was markedly enhanced during the aura.

Adolescent↗
PubMed1989

Attentional mechanisms during the intracarotid amobarbital test.

We investigated the integrity of attentional mechanisms following unilateral intracarotid amobarbital injection in 23 patients undergoing preoperative evaluation for epilepsy surgery. Performance for ipsilateral hand-button response to a quasi-random strobe flash was markedly altered following unilateral amobarbital injection as evidenced by decreased correct responses and increased perseverative errors. The increase in perseverations was inversely correlated with subsequent memory performance. The results indicate that unilateral amobarbital injection commonly produces a marked reduction in attention as well as disturbances in strategic control mechanisms.

Adolescent↗
PubMed1989

Two cases of anterior choroidal artery territory infarction.

Occlusion of the anterior choroidal artery (AChA) can cause infarction in the posterior limb of the internal capsule. Infarction is less frequently observed in the thalamus, midbrain, temporal lobe, and lateral geniculate body (LGB) territories of the AChA. The most common clinical finding is hemiparesis. Hemianesthesia may be severe at onset but is usually transient. Homonymous hemianopia, upper-quadrant anopia, or upper- and lower-quadrant sector anopia can be present. Occasionally these patients are reported to have transient abnormalities of higher cortical function. The most common stroke mechanism is known to be small-vessel occlusive disease, predominantly found in hypertensive and diabetic patients. Vasospasm due to ruptured aneurysm or intraoperative mechanical manipulation, and cardiac origin the AChA territory. The infarct lesion is usually recognized and diagnosed by computed tomography. The best treatment is still unknown.

Aged↗
PubMed1987

Analysis of a four-year experience with depth electrodes and a two-year experience with subdural electrodes in the evaluation of ablative seizure surgery candidates.

Chronically implanted depth and subdural electrodes have both been shown to be satisfactory means of localizing epileptogenic foci. Utilizing bilateral mesial temporal depth electrodes, we have localized mesial temporal foci in a large percentage of patients. Depth electrode investigation of a more limited number of patients with suspected extramesial temporal foci has not been as reliable in giving localizing information. We have more recently used subdural electrodes to investigate this latter category of patients, and preliminary findings suggest that this technique may be of localizing value in several subcategories.

Electrodes, Implanted↗
PubMed1976

Tissue distribution and characteristics of xanthine oxidase and allopurinol oxidizing enzyme.

Tissue distribution and levels of allopurinol oxidizing enzyme and xanthine oxidase with hypoxanthine as a substrate were compared with supernatant fractions from various tissues of mice and from liver of mice, rats, guinea pigs and rabbits. The allopurinol oxidizing enzyme activities in liver were quite different among the species and the sex difference of the enzyme activity only in mouse liver. In mice, the highest activity of allopurinol oxidizing enzyme was found in the liver with a trace value in lung, but the enzyme activity was not detected in brain, small intestine and kidney, while the highest activity of xanthine oxidase was detected in small intestine, lung, liver and kidney in that sequence. The allopurinol oxidizing enzyme activity in mouse liver supernatant fraction did not change after storage at -20 degrees C or dialysis against 0.1 M Tris-HCl containing 1.15% KCl, but the activity markedly decreased after dialysis against 0.1 M Tris-HCl. On the contrary, the xanthine oxidase was activated 2 to 3 times the usual activity after storage at -20 degrees C or dialysis of the enzyme preparation. These results indicated that allopurinol was hydroxylated to oxipurinol mainly by the enzyme which is not identical to xanthine oxidase in vivo. A possible role of aldehyde oxidase involved in the allopurinol oxidation in liver supernatant fraction was dicussed.

Allopurinol↗
PubMed1975

[Hepatic allopurinol oxidizing enzyme in mice].

The relationship between allopurinol oxidizing enzyme and aldehyde oxidase was investaged in mice. The oxidation of both N-methylnicotinamide and allopurinol appears to be catalized by a single enzyme, aldehyde oxidase (aldehyde-oxygen oxidoreductase EC, 1.2.3.1.). This conclusion is based on the following evidence; The postnatal changes of allopurinol and N-methylnicotinamide oxidizing activities were similar during growth and the levels of both activities increased in a parallel fashion upon the attainment of sexual maturity. The rates of loss of the activities of both enzymes by heat denaturation as well as dexamethasone administration were similar. The inhibitors of allopurinol oxidizing enzyme also suppressed N-methylnicotinamide oxidation. Competition of N-methylnicotineamide and allopurinol for oxidation was demonstrated. The rate of increase of the activities in both enzymes was almost parallel during each step of the purification from mouse liver supernatant. It was ascertained that xanthine oxidase in the enzyme preparation does not influence allopurinol oxidation.

Aldehyde Oxidoreductases↗
PubMedDate not supplied

Spectral analysis of sphenoidal evoked potentials predicts epileptic focus.

Sphenoidal evoked potentials (SpEPs) were recorded in 14 patients with intractable temporal lobe epilepsy. Twelve patients had electrographically proven unilateral seizure onset (five left, seven right). Two patients had partial complex seizures and unilateral mesial temporal lobe lesions shown by magnetic resonance imaging (MRI). Thirteen patients subsequently underwent temporal lobectomy. SpEPs were recorded using the P3 tonal oddball paradigm from sphenoidal electrodes referenced to scalp electrodes (i.e., T3, T4, C3, C4, Cz) and were subjected to spectral analysis for whole band (1-12.6 Hz) power. A significant relationship was found for side of seizure focus and reduced spectral power of the sphenoidal-temporal target SpEPs. In 10 of 14 patients, SpEP spectral power was less from the "epileptogenic" than from the "nonepileptogenic" temporal lobe. Of the remaining 4 patients, 2 had bilaterally equal spectral power, and 2 had lower SpEP power from the nonepileptogenic side. Postoperatively, all 13 patients are seizure-free except for the 2 patients with reduced SpEP power opposite to the ictal onset and 1 patient with fluctuations in SpEP asymmetries. Spectral analysis of SpEPs appears to have utility in the assessment of temporal lobe dysfunction and thus in the preoperative evaluation for epilepsy surgery.

Adolescent↗