[Proximal spinal muscular atrophies].

The author observed 24 patients with proximal spinal muscular atrophies (PSMA) 15 of whom were suffering from Kugelberg-Welander's disease, and 9 from the intermediate form. In addition to the conventional neurological examinations carried out in all the patients, 11 patients were also examined electroneuromyographically. A genetic analysis of affected families was performed. The analysis showed that the disease forms being studied were inherited according to the autosomo-recessive type: this was in agreement with literary data. The age of the disease onset, the clinical manifestations of the disease, particularly, the character of the atrophies and their prevalent localization; the course and the degree of the disease progress, and the prognosis were also analyzed. The author discusses the character of the electroneuromyograms that showed a typical picture of motoneuron affection, while the conductivity of motor nerves remained normal, though showed signs of an increase of motor unit parameters with a decrease of the number of voluntarily-activated units, i.e. a diminution of mobilization. The degree of the EMG amplitude lowering during voluntary muscular contractions correlated with the disease gravity. The speed of the impulse conduction was normal. The data presented may be of a certain significance for medico-genetic consultations.