Biomedical subjects
Publications and source records attributed to C Coërs.
In patients complaining of muscle cramps and exertional myalgia, we found a significant decrease of type 1 muscle fiber proportion in comparison with a control group. The possible mechanism of this change is discussed.
Neurological, ophthalmological and genetic investigations were performed on a family, a member of which presented with a rare association of tapeto-retinal degeneration, protanopia and Charcot-Marie-Tooth disease (CMT), and asked for genetic counseling. The neurological enquiry was completed by measurement of motor nerve conduction velocity in several completed by measurement of motor nerve conduction velocity in several members of the family. The propositus was submitted to a muscle biopsy. The ophthalmological examination included ophthalmoscopy, fluorescein angiography, electroretinogram and electrooculogram. The propositus, a woman aged 40, had typical CMT disease and her father also had a mild form of it. She had protanopia as had her father, her son and her nephew. In addition she had large macular pigmented changes, described as retinal dystrophy, "flavus flavimaculatus." Her mother had only senile pigmented modification of the fundus and her three daughters had mild macular pigmented changes, like "salt and pepper." Two genes are probably involved: one for protanopia with X linked recessive inheritance, the other responsible of CMT and tapeto-retinal degeneration, with an autosomal dominant inheritance, giving a 50% risk of recurrence.
Neuromuscular biopsies from 18 patients with proximal muscle weakness were classified electromyographically as myopathy (11 cases), denervation (3 cases), or inconclusive (4 cases). Myopathic changes of muscle fibers occurred in all biopsies. Small angular dark fibers were observed in nine biopsies, and small-group atrophy in four biopsies from the three above-mentioned groups. Two biopsies classified as denervation showed large-group atrophy. Terminal innervation ratio (TIR) was increased only in the three cases classified as denervation and in one inconclusive case. TIR, which is more closely correlated with electromyographic (EMG) results than are muscle fiber changes, may help differentiate spinal muscular atrophy from limb-girdle muscular dystrophy.
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The observation of a 20 years old patient with a periodic paralysis is reported. During a crisis induced by 20 U of insulin and 150 g of glucose, transient hyperaldosteronism was found and the muscular biopsy performed in the left biceps brachii, disclosed vacuoles with a double membrane. The significance of these findings is discussed.
Two patients, a brother and sister, both suffering from congenital generalized muscle weakness with a progressive course are reported. Muscle biopsy revealed areas with loss of cross striations in the muscle fibers, electronmicroscopically presenting complete disorganization of the myofibrils with streaming of the Z discs and absence of mitochondria. Vesicular nuclei with prominent nucleoli were present in these areas. There was a type I fiber predominance in both cases. The mean diameter of the type I muscle fibers in one of the cases was too small. Motor endplate alterations in this patient gave no evidence of denervation but were suggestive of a delayed development of motor nerves.
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We studied the intramuscular motor innervation in 19 muscle biopsy specimens from boys with Duchenne's muscular dystrophy and the fiber-type pattern was analyzed in nine biopsy specimens. The main change in motor innervation was a longitudinal displacement of motor end plates that could reach 10 mm and the presence of numerous unemployed axons ending freely within connective tissue. There was no increased collateral ramification of subterminal axons and the terminal innervation ratio was normal. The fiber-type pattern was characterized by a random variation of fiber diameters, a slight predominance of type 1 fibers, and an impared type differentiation in many fibers. The morphological data do not support the possibility of denervation and collateral reinnervation that could be related to the late component potentials found in Duchenne's muscular dystrophy.
Neuromuscular biopsies were obtained from 45 myasthenic patients. Motor innervation was studied in all specimens by vital staining with methylene blue. Quantitative data included the proportion of elongated motor endings, and the terminal innervation ratio (TIR) of motor axons. Quantitative histochemical data, obtained on 12 biopsies, included the atrophy factors of type I and II fibers, the I/II ratio, and the proportion of fibers strongly reacting to both ATPase and NADH diaphorase (type III fibers). Statistical analysis of the data led to the following conclusions: (1) elongated motor endings, found in 26 biopsies, were not related to denervation or to the severity of the disease, and were preferentially observed in younger patients; (2) increased TIR suggesting denervation was observed in 7 biopsies, only in patients over 50 years; and (3) various histochemical changes were found, mainly numeric reduction of type II fibers, having no demonstrable relationship with the incidence of elongated motor endings. The highest TIR was observed in a biopsy containing an increased proportion of type III and intermediate muscle fibers.
Changes in motor innervation were compared with histologic and histochemical pattern of muscle fibers in three biopsies of central core disease, four biopsies of nemaline myopathy, one biopsy of myotubular myopathy, and three biopsies of mitochondrial myopathy. Evidence of collateral reinnervation was obtained only in one biopsy from central core disease. In other biopsies, no structural or ultrastructural abnormality of axis cylinders, myelin, or myoneural junction suggesting denervation were observed. The only relevant change found in centronuclear myopathy and to a lesser extent in nemaline myopathy was an unusual smallness and simplication of motor endings, suggesting delayed or impaired maturation. Muscle fibers strongly reactive for both adenosinetriphosphatase and nicotinamide-adenine dinucleotide diaphorase, observed in central core disease and mitochondrial myopathy, were not associated with increased terminal innervation ratio.
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A quantitive study of the terminal innervation ratio (TIR) was conducted using 18 amyotrophic lateral sclerosis (ALS) and 12 Charcot-Marie-Tooth disease (CMT) muscle biopsies. Morphometric and histochemical analyses of muscle fibers were performed in 9 ALS and 6 CMT biopsies. The results revealed that TIR and type grouping were significantly greater in CMT than in ALS. The proportion of type 3 fibers was higher in ALS, though the proportion of intermediate and type 0 fibers was significantly higher in CMT. The atrophy factor was significantly greater in type 3 than in types 1 and 2 fibers, but it was not significantly different in type 0 and intermediate fibers as compared to types 1 and 2, It appears, therefore, that CMT has a better capacity for collateral reinnervation than ALS. Type 0 and intermediate fibers may represent altered endproducts of successful collateral reinnervation.
The motor innervation in muscle biopsies from 45 myasthenic patients was studied by intravital staining with methylene blue. The enzymatic pattern and fibre type distribution was analysed in 12 cases. Quantitative data including the proportion of elongated motor endings and the terminal innervation ratio (TIR) of motor axons, were compared to histochemical data and to clinical data including age of patients. The incidence of elongated motor endings tends to be greater in younger patients, whereas an increased collateral ramification of motor axons occurs only after the age of 50. Small type III fibers suggesting denervation are also found in elderly patients only. The significance of these morphological differences in relation to age is discussed.