The Relationship between Hyperhomocysteinemia and C677T MTHFR Gene Polymorphism in Patients with Ischemic Stroke

BACKGROUND: Hyperhomocysteinemia is an independent risk factor for cerebrovascular disease. MTHFR 677TT genotype can induce hyperhomocysteinemia. However, the association between this 677TT genotype and ischemic stroke still remains controversial. This study was undertaken to determine whether MTHFR 677TT genotype was associated with certain subtype of ischemic stroke. METHODS: The case group consisted of 129 patients with ischemic stroke and the control group consisted of 157 healthy individuals. We checked their fasting plasma homocysteine levels and analyzed the C677T mutation in the MTHFR gene. The relative risk of MTHFR 677TT genotype was assessed by odds ratios using multivariate logistic regression. RESULTS: Homocysteine levels in plasma were significantly higher in ischemic stroke patients (10.386.44 mol/L) than in controls (8.002.40) (P<0.05). In small-artery disease (11.366.01), the same result was found (P<0.05). On the other hand, the prevalence of the homozygote mutation was not significantly higher in ischemic stroke patients (20.2%) than in controls (13.4%) (adjusted OR 1.39, 95% CI 0.65 to 2.96). The adjusted OR and 95% CI was 2.59 (1.08 to 6.25) for the TT genotype in patients with small-artery disease compared to controls. The 677TT genotype was increased in small-artery disease compared to large-artery disease (adjusted OR 7.60, 95% CI 1.66 to 34.77). CONCLUSIONS: Our findings suggest that the homozygous C677T mutation in the MTHFR gene is a risk predictor in the subtype of ischemic stroke, such as small-artery disease.

Cognitive Function in Epileptic Patients Treated with Oxcarbazepine: Neuropsychologic test and Event-related Potential

BACKGROUND: Antiepileptic drugs (AEDs) may impair cognitive function in epileptic patients. Oxcarbazepine (OXC, Trileptal(R)) is a recently developed AED. The effect of oxcarbazepine (OXC, Trileptal(R)) monotherapy on cognitive func-tion was studied prospectively in patients with partial or generalized epilepsies. METHODS: A total of 22 patients were started on OXC monotherapy and 18 out of them completed a 1-year follow-up. Nine patients didn't have any previous history of anticonvulsant medications. OXC was administered 600 to 1,500 mg twice daily after 10 to 14 days of titra-tion period. We used neuropsycological assessments (verbal learning and memory, visual memory, digit span, Trail Making, and verbal fluency) and auditory event-related potentials (P300) for the evaluation of cognitive function before and 1 year after OXC treatment. RESULTS: Twelve patients became seizure free and 6 patients showed the reduction in monthly seizure frequency. The adverse effects of medication were mild weight gain, GI problems, dizziness, fatigue and headache etc., but they were transient. In particular one patient experienced a feeling of alertness and clear-headed-ness with continuation of the medication. Neuropsycological tests showed a significant improvement of performance in verbal learning, word recognition and Trail Making test of type A. P300 latencies were significantly shortened, but their amplitudes were not changed. CONCLUSIONS: Even though many variable factors such as the age at onset of epilepsy, etiology of epilepsy, seizure frequency, seizure type, epileptic process itself and dosage of antiepileptic drugs influence cognitive function of epileptic patients, OXC at least does not seem to be harmful or rather slightly beneficial for cogni-tive functions.

Hand-Arm Vibration Syndrome and Neural Conduction Impairment in Swagging Workers Exposed to Hand-Arm Vibration / 대한산업의학회지

OBJECTIVES: To investigate the hand-arm vibration syndrome (HAVS) among symptomatic swagging workers exposed to hand-arm vibration, using medical evaluation and measurement of workplace vibration. Furthermore, to evaluate the neurophysiological METHODS: Four workers showing symptoms relevant to HAVS were evaluated. Medical evaluation consisted of medical interview, questionnaire, nail-bed compression test, and sensory perception tests for vibration and pain. Some other diseases were excluded by a medical interview, hematological assessment, and urinalysis. Cold provocation test was used to assess the peripheral vascular changes, and a nerve conduction velocity (NCV) test was implemented to ascertain the peripheral neural changes. Pegboard, hole plate, and tapping board tests were performed to assess motor nerve function. The hand-arm vibration acceleration levels of the swagging machines were measured. Six months later, follow-up NCV tests were performed. RESULTS: The actual exposure time to vibration was not longer than 15 minutes per day. The hand-arm vibration acceleration levels of the swagging machines, according to actual exposure time, were from 3.63 to 12.98 m/sec2, by ISO 5349. The vibratory perception thresholds and the recovery time of a nail color following finger cooling were significantly increased in all four workers. The perception of pain was mildly increased. The nerve conduction studies at first diagnosis and follow-up showed multifocal neural impairment caused by vibration. However, we could not rule out the concomitant presence of the carpal tunnel syndrome in one worker. CONCLUSIONS: These results show that HAVS can be caused by hand-arm vibration in swagging workers. Interestingly, the NCV results suggested that vibration-induced neural conduction impairments could vary, and need to be interpreted cautiously.

Evaluation of Anterior Cerebral Artery Flow Abnormalities on Transcranial Doppler Ultrasonography

BACKGROUND: Anterior cerebral artery (ACA) flow abnormalities on a transcranial Doppler ultrasonography (TCD) represent various conditions, which include hyperemic collateral to the ipsilateral middle cerebral artery (iMCA) or contralateral internal carotid artery (cICA) pathology, and ipsilateral anterior cerebral artery (iACA) stenosis. However, studies related to these conditions have rarely been done. We evaluated the hemodynamic significance of ACA flow abnormalities on TCD without angiographic information. METHODS: We analyzed TCD records, which were recruited consecutively during a 10-month period in our laboratory. ACA abnormalities on TCD were defined as follows: 1) mean flow velocities (mFV) of ACA>80 cm/sec; 2) ipsilateral mFV ACA/MCA> 1.2; 3) anterior cerebral artery veloci-ty ratios (ACAVR)> 1.34. We then correlated TCD patterns with a magnetic resonance angiography (MRA) or trans-femoral cerebral angiography (TFCA). RESULTS: Thirty-five patients were recruited to participate in this study. Based on MRA or TFCA, we found 4 patterns of vascular status which could explain the ACA abnormalities on the TCD. The iMCA pathology was demonstrated in 14 cases, cICA pathology in 11 cases, iACA stenosis in 3 cases, and cACA hypoplasia in 5 cases. Eight cases did not show any vascular pathology. CONCLUSIONS: ACA flow abnormalities should be evaluated with absolute flow velocity indicies, as well as other indexes, which mostly signify hyperemic collateral flow to the iMCA or cICA steno-occlusion. (J Korean Neurol Assoc 19(4):349~353, 2001)

A Case of Mitochondrial Neurogastrointestinal Encephalomyopathy

Mitochondrial neurogastrointestinal encephalomyopahty (MNGIE) is a rare disorder and is clinically characterized by ophthalmoparesis, peripheral neuropathy, leukoencephalopathy, gastrointestinal symptoms with intestinal dysmotility, and histologically abnormal mitochondria in muscle. A 32-year-old female showed external ophthalmoparesis, bilateral ptosis, quadriparesis, and sensory change below both ankle joints. Level of serum lactic acid was highly increased. The brain MRI showed diffusely increased signal intensity in the centrum semiovale and white matter. Electron microscopic finding showed paracrystalline inclusions in mitochondria of a few muscle fibers. (J Korean Neurol Assoc 19(3):309~312, 2001)

Investigation of Facial Nerve with the Response to Magnetic & Electrical Stimulation and Clinical Application

We studied 54 normal volunteers and 30 patients with Bell's palsy by magnetically and electrically evoked direct stimulations of facial nerve. A magnetic coil was placed tangentially to the parieto-occipital area and the stylomastoid foramen. Magnetic stimulation (MS) was less painful and able to excite deeper tying neural structures. Magnetically and electrically evoked direct stimulations of facial nerve showed the same characteristics in excitability and nerve conduction, but they could not be evaluated on the basis of the same normative data. We identified a locus of the impulse generation that might be closer to the exit of facial nerve from the brainstem. Compared with normal controls, MS-evoked CMAPS of patients with Bell's palsy had no responses, longer latencies, lower amplitudes, or disperses pattern. This study shown that MS at the stylomastoid foramen can not be used for the evaluation of the facial nerve conduction study in place of electrical stimulation(ES). As the transcranial MS can stimulate intracranial proximal portion of facial nerve directly and noninvasively, it can give additional information on the evaluation of facial nerve. Transcranial MS combined with ES may provide the means for assessing the entire facial nerve.

MRI Findings in Lateral Medullary Syndrome According to the Patterns of Sensory Deficits

The lateral medullary syndrome, I. E. Wallenberg syndrome, presents with several forms of sensory deficits. However, the correlation between the sensory deficits and the MRI findings of the medulla has been rarely attempted. We studied 16 patients with lateral medullary infarction who showed appropriate MRI lesions and correlated their sensory findings with the MRI results. In order to examine the extent of lesion of medulla in the MRI, we divided the medulla into three parts, namely upper, middle, and lower parts. The patients exhibited six types of sensory manifestation. In brain MRI, five patients with uncrossed sensory deficit; three patients with contralateral sensory deficit involving only body; and one patient with contralateral sensory level on trunk showed a diagonal band, lateral, or combined lesion in the medulla. Four patients with crossed sensory deficit and one patient with ipsilateral sensory deficit involving only face showed a large, laterodorsal lesion in the medulla. Two patients without sensory deficit exhibited a dorsal lesion in the medulla. In conclusion, lateral medullary syndrome usually has a characteristic lesion in the MRI according to the sensory deficits.

Choreoballism Associated with Diabetic Ketoacidosis and Bilateral Basal Ganglia Calcification

Various structural lesions as well as metabolic derangements cause choreoballism. Hyperglycemia can induce diverse neurologic dysfunctions. There are few case reports of dyskinesias associated with hyperglycemia or diabetic ketoacidosis. A 19-year-old girl with insulin dependent diabetes mellitus presented with bilateral choreoballism. She had diabetic ketoacidosis. Her dyskinesia improved with control of high blood glucose and ketoacidosis. Though she had bilateral basal ganglia calcification, the chance of its contribution to dyskinesia was very slim. We advise physicians to keep in mind that treatable hyperglycemia can cause dyskinesia.

Two Cases of Asymmetric Crying Facies: Congenital Agenesis of the Depressor Anguli Oris Muscle

Asymmetric crying facies are caused by unilateral weakness of the depressor muscles of lower lip, which is most obvious during crying and is associated with other congenital anomalies, especially congenital heart disease. This sign results from partial paralysis of facial nerve, specifically the ramus marginalis mandibulae, or congenital agenesis of the depressor anguli oris muscle (DAOM). We report two patients with congenital hypoplasia or absence of DAOM proved by electromyography, who have not cardiac anomalies.

A Case of Neuroleptic Malignant Syndrome associated with Choreoballism due to the Delayed Complication of Carbon Monoxide Intoxication

Neurologic complications such as mental status changes, incontinence, gait disturbances, extrapyramidal symptoms may be delayed days or weeks after exposure to carbon monoxide but hyperkinesia such as choreoballism and athetosis rarely occurs as symptoms of delayed neurologic complication of carbon monoxide intoxication. Neuroleptic malignant syandrome (NMS) is a rare, potentially fatal drug-induced disorder associated with hyperthermia, muscle rigidity, autonomic instability, mental dysfunction and various dyskinesia. Various major neuroleptic drugs seem to be its culprits. We describe a 24-year-old female patient who presented with NMS following administration of haloperidol for choreoballism, a symptom of delayed neurologic sequelas after carbon monoxide intoxication, with a review of the literature.