A case of bilateral alternating hemifacial spasms.

We report a 24-year old woman who developed bilateral hemifacial spasm alternating from one side to the other. The spasms followed a left peripheral facial palsy 2 years previously. This unusual type of bilateral hemifacial spasm was possibly due to lesions of multiple sclerosis in the brainstem.     

The elimination rate of 123I-heptadecanoic acid after intracoronary and intravenous administration

When calculating the elimination rate of radioactivity after the administration of radioiodinated heptadecanoic acid (123I-HDA), background correction is necessary due to the high level of background activity. In the present study, the subtraction method of Freundlieb et al. was investigated on validity. This was done by comparing the half-time values of the elimination rate after intravenous (i.v.) and intracoronary (i.c.) injection. In the latter case, no background correction was necessary. Six patients undergoing cardiac catheterization were studied. Scintigraphy was performed after the injection of 123I-HDA into the left coronary artery and after i.v. injection. Half-time values were calculated from regions of interest drawn over myocardium perfused by the left-anterior descending branch (LAD) and the left circumflex artery (LCX). In the LAD region, the mean half-time value in the i.c. study was 22 min, while in the corrected i.v. study, the mean value was 27 min. In the LCX region, the half-time values were 24 and 33 min, respectively. The background-subtraction procedure proposed by Freundlieb et al. for i.v.-injected 123I-HDA is incomplete, as it resulted in half-time values that were higher than those of the i.c. study.     

The elimination rate of 123I-heptadecanoic acid after intracoronary and intravenous administration

When calculating the elimination rate of radioactivity after the administration of radioiodinated heptadecanoic acid (¹²³I-HDA), background correction is necessary due to the high level of background activity. In the present study, the subtraction method of Freundlieb et al. was investigated on validity. This was done by comparing the half-time values of the elimination rate after intravenous (i.v.) and intracoronary (i.c.) injection. In the latter case, no background correction was necessary. Six patients underoging cardiac catheterization were studied. Scintigraphy was performed after the injection of ¹²³I-HDA into the left coronary artery and after i.v. injection. Half-time values were calculated from regions of interest drawn over myocardium perfused by the left-anterior descending branch (LAD) and the left circumflex artery (LCX). In the LAD region, the mean half-time value in the i.c. study was 22 min, while in the corrected i.v. study, the mean value was 27 min. In the LCX region, the half-time values were 24 and 33 min, respectively. The background-subtraction procedure proposed by Freundlieb et al. for i.v.-injected ¹²³I-HDA ss incomplete, as it resulted in half-time values that were higher than those of the i.c. study.     

Mosaic trisomy (8)(p22 --> pter) in a fetus caused by a supernumerary marker chromosome without alphoid sequences

OBJECTIVE: Our objective was to characterise a marker chromosome in cultured amniocytes of a fetus with a mos 47,XX,+mar[3]/46,XX[14] karyotype. METHODS: The indication for prenatal cytogenetic analysis of cultured amniocytes was advanced maternal age. Classic banding techniques (GTG- and C-banding) were performed. Microdissection combined with reverse painting was used to disclose the exact origin of the marker; the result was confirmed by chromosome painting and FISH with band-specific probes. RESULTS: Analysis of GTG-banded chromosomes showed a small marker chromosome in 3 of the 17 colonies analysed. Subsequently, C-banding showed no alphoid sequences, suggesting the presence of a neocentromere. The parent's karyotypes were normal. After normal ultrasound findings, the parents decided to continue the pregnancy. Chromosome analysis in peripheral blood after birth demonstrated that the marker chromosome was present in 50% of the lymphocytes. Using microFISH, the marker was further characterised and appeared to be derived from chromosome region (8)(p22 --> pter). CONCLUSION: Accurate identification of the marker chromosome was very important for prenatal counselling. Combining the results of GTG- and C-banding analysis with the results of the (micro)FISH, we concluded that the patient's karyotype is: mos 47,XX,+mar.rev ish der(8)(p22 --> pter)[50]/46,XX[50].     

Measurement of the energy-generating capacity of human muscle mitochondria: diagnostic procedure and application to human pathology

BACKGROUND: Diagnosis of mitochondrial disorders usually requires a muscle biopsy to examine mitochondrial function. We describe our diagnostic procedure and results for 29 patients with mitochondrial disorders. METHODS: Muscle biopsies were from 43 healthy individuals and 29 patients with defects in one of the oxidative phosphorylation (OXPHOS) complexes, the pyruvate dehydrogenase complex (PDHc), or the adenine nucleotide translocator (ANT). Homogenized muscle samples were used to determine the oxidation rates of radiolabeled pyruvate, malate, and succinate in the absence or presence of various acetyl Co-A donors and acceptors, as well as specific inhibitors of tricarboxylic acid cycle or OXPHOS enzymes. We determined the rate of ATP production from oxidation of pyruvate. RESULTS: Each defect in the energy-generating system produced a specific combination of substrate oxidation impairments. PDHc deficiencies decreased substrate oxidation reactions containing pyruvate. Defects in complexes I, III, and IV decreased oxidation of pyruvate plus malate, with normal to mildly diminished oxidation of pyruvate plus carnitine. In complex V defects, pyruvate oxidation improved by addition of carbonyl cyanide 3-chlorophenyl hydrazone, whereas other oxidation rates were decreased. In most patients, ATP production was decreased. CONCLUSION: The proposed method can be successfully applied to the diagnosis of defects in PDHc, OXPHOS complexes, and ANT.     

Na+-K+-ATPase is not involved in the warming-up phenomenon in generalized myotonia

The initial temporary weakness that occurs in autosomal-recessive generalized myotonia diminishes with repetitive contractions. Physiological understanding of this phenomenon is incomplete. The underlying hypothesis of our study was that the "warming-up" phenomenon relates to the exercise-related activation of Na(+)-K(+)-ATPase. Three patients performed isometric exercise of the brachioradialis muscle on two separate days. Randomly, on one of these days the contraction was preceded by a 30-min infusion of the Na(+)-K(+)-ATPase inhibitor ouabain into the brachial artery of the exercising arm (0.4 mug.min(-1).dl(-1)). Force was measured simultaneously with electrical muscle activity using high-density surface electromyography (HD-sEMG). A transient rapid decline in force occurred after initiation of exercise, accompanied by electrophysiological changes indicating sarcolemmal conduction block. Ouabain infusion did not affect the recovery from transient paresis or the accompanying electromyographic changes, indicating that the warming-up phenomenon in generalized myotonia is not mediated by Na(+)-K(+)-ATPase.     

Quadriceps weakness in a family with nemaline myopathy: influence of knee angle

Nemaline myopathy is a congenital neuromuscular disorder, which primarily affects the thin filaments. Clinically the most important feature is muscle weakness; however, this weakness is poorly understood. The present investigation aimed to determine the torque angle relationship of the knee extensor muscles during in vivo muscle contractions in a family with a novel phenotype of nemaline myopathy. The results of this study show that quadriceps weakness occurs predominantly at higher knee flexion angles, but relatively normal strength was found at angles closer to full knee extension. When the relative torque angle relationships were considered, torque loss at smaller than optimum knee flexion angle was greater in the patients compared with the controls. In addition, the optimum angle for maximal quadriceps torque production was shifted towards smaller knee flexion angles in the patients. This suggests that a weakness specifically at higher knee flexion angles probably occurs as a result of adaptations consequently to the disease. Furthermore, it is important to assess muscle function at different joint positions to allow adequate interpretation of muscle weakness.