Several medications are approved to treat coronavirus disease 2019 (COVID-19) in Korea including nirmatrelvir/ritonavir, remdesivir, and regdanvimab. There is potential drug-drug interaction between antiepileptic drugs (AEDs) and the medications used to treat COVID-19. Several AEDs such as phenytoin, carbamazepine, phenobarbital, and primidone are strong cytochrome P450 inducers and can inhibit the drugs used for COVID-19. Particularly, these drugs are contraindicated with nirmatrelvir/ritonavir (Paxlovid®). There is a weaker drug-drug interaction between the AEDs and remdesivir. No significant interaction has been reported between the AEDs and molnupiravir. Pharmacokinetic interactions of the AEDs are important in effective management of COVID-19 in patients with epilepsy.

A characteristic imaging finding in cases of methanol intoxication is putaminal necrosis, but its presence is usually not suspected due to its rarity. Methanol intoxication generally produces serious neurological symptoms that include visual disturbances and diminished consciousness, characteristically with metabolic acidosis. We reported the case of a 59-year-old man who was admitted to the hospital with diminished consciousness. Acute methanol intoxication was determined as the cause. Laboratory tests revealed high anion gap metabolic acidosis. Diffusion-weighted MRI indicated diffuse symmetric diffusion restriction lesions in the subcortical white matter of both cerebral hemispheres.
Acid-Base Equilibrium ; Acidosis ; Brain Diseases* ; Cerebrum ; Consciousness ; Diffusion ; Humans ; Magnetic Resonance Imaging ; Methanol ; Middle Aged ; Necrosis ; White Matter

BACKGROUND: Nerve conduction study (NCS) is an objective and quantitative test in evaluating peripheral nerve disorders. Several physiological and technical factors are well known to influence the results of NCS, which can be controlled and regulated by standardization of environment and through the process to make range of normality. However, most electromyographers do not pay much attentions about inter- and intra-examiner variabilities, and there are only a few and incomplete reports on these topics. We examined the intra-examiner variability of NCS on the basis of periods of practice. METHODS: Twenty-eight electromyographers were divided into two groups: residents and neurologist-technicians. All, having variable NCS training periods, have performed NCS on one of other 27 electromyographers ten times within two weeks where each study was made once a day. RESULTS: Coefficient of variation and external quotient increased according to the following order - nerve conduction velocities (NCV), terminal latencies (TL), and amplitudes of compound action potentials (AMP). There were significant differences between the two groups in NCV and TL, but no statistical difference in AMP. CONCLUSIONS: Our results suggest that errors from intra-examiner variability should be considered when interpreting NCS and that those electromyographers who have enough training should perform NCS.
Action Potentials ; Attention ; Humans ; Neural Conduction* ; Peripheral Nerves

BACKGROUND: Myotonic dystrophy is the most common type of muscular dystrophy affecting adults, associated with the expansion of triplet repeat DNA sequences. A hallmark of the inherited disease with trinucleotide repeat DNA expansion is the clinical and genetic anticipation. The copy numbers of the CTG repeat are known to be related to the severity and the onset age of clinical symptoms. METHODS: The copy numbers of the CTG repeats were determined using PCR amplification and Southern blotting. The clinical manisfestations of 34 patients from 14 families who had the CTG repeat expansion were evaluated based on the muscular disability rating scale and the electrophysiological study. RESULTS: There was a significant positive correlation between the clinical scores and the size of the amplification of trinucleotide repeat, and a negative correlation with the age of onset. In 9 patients with copy numbers of CTG repeats between 61 and 100, 8 cases were asymptomatic and myotonic discharges were not seen in 71% of patients. Larger expanded bands, earlier onset, and worse symptoms were evident with each successive generation. CONCLUSIONS: Molecular genetic analysis with CTG repeat expansion might be useful in the detection and the genetic counseling of myotonic dystrophy patients.
Adult ; Age of Onset ; Anticipation, Genetic ; Base Sequence ; Blotting, Southern ; DNA ; Genetic Counseling ; Humans ; Molecular Biology ; Muscular Dystrophies ; Myotonic Dystrophy* ; Polymerase Chain Reaction ; Trinucleotide Repeats

The Lambert-Eaton myasthenic syndrome (LEMS) heralds the occurrence of malignancy, especially small-cell lung cancer (SCLC), but it can also occur in the absence of cancer. Twelve patients were diagnosed as LEMS by clinical features and the classical electrophysiological triad, which includes a low amplitude of compound muscle action potentials (CMAP), decremental responses on low-rate stimulation, and incremental responses on high-rate stimulation on the repetitive nerve stimulation (RNS) test. There were 6 male and 6 female patients, ranging in age from 49 to 66 years. Malignancy(all were SCLC) was found in 7 patients. Males predominantly expressed the paraneoplastic form; whereas the primary autoimmune form was found only in women, who showed a good response to corticosteroid treatment. The neurological features were similar in both groups: proximal lower limb weakness, depressed muscle stretch reflexes, and dryness of mouth in nearly all patients. Bulbar dysfunction and limb paresthesia were a little more frequent in the paraneoplastic form. In RNS tests, the characteristic electrophysiological abnormalities were found in all patients and were more profound in the paraneoplastic form. We concluded that LEMS is commonly associated with malignancy, especially SCLC, but it should also be stressed that there are many female LEMS patients who do not harbor any malignancy at all, and that other treatment strategies such as immunotherapy should be considered for these patients.
Aged ; Carcinoma, Small Cell/complications ; Female ; Human ; Lambert-Eaton Myasthenic Syndrome/therapy ; Lambert-Eaton Myasthenic Syndrome/physiopathology* ; Lung Neoplasms/complications ; Male ; Middle Age ; Paraneoplastic Syndromes/physiopathology

We think that the clinical courses of lacurlar infarctions are somewhat different from those of cortical ones, because the ischemic penumbra, a keystone of acute infarct recovery, of the former is rnore limitted than that of the latter. Therefore, we analyzed the selected data, 38 cortical and 33 lacunar infarct patients, from Severance Stroke Registry which were recorded from May, 1989 to April, 1990, to demonstrate and compare the differences of the clinical courses and its influencing factors between the cortical and lacunar infarcts. Our results suggested as follows first, the initial neurologic deficits of cortical infarctions are rnore serious than those of lacunar infarctions, but with the better short-term improvements of tbe former, the short-term motor outcome between the two types of infarcts are not significantly different second, whiIe the short-term improvernent of cortical infarcs is influenced by initial hematocrit level, the short-term motor outcome and the degree of improvement of lacunar infarcts are influenced by the patient's age.
Cerebral Infarction* ; Hematocrit ; Humans ; Infarction ; Neurologic Manifestations ; Stroke ; Stroke, Lacunar*