AMYOTROPHIE SPINALE INFANTILE

Abstract

The authors report 100 cases with prolonged spinal muscular atrophy (SMA) and survival beyond 4 years old. There were 46 boys and 54 girls. 23 of them had histories with an autosomal recessive form of inheritance. Once case had a dominant form. The unity of cases described as Werdnig Hoffmann disease [SMA I, SMA II (Childhood), and SMA III (Kugelberg Welander)] is supported and our cases fell in three groups according to their ambulatory capabilities: never acquired, lost, or retained. 71 cases have never walked: the onset of symptoms was noted at an average age of 6.4 months ± 3; the average age at the last examination was 16 years (4-39). Death occurred in 6 cases. Loss of walking occurred in 24 cases: the onset of symptoms was noted at an average age of 17.4 months ± 14.2 5 cases were still ambulatory: the onset of symptoms was noted at an average age of 2.4 years ± 2.8. For these last 29 cases the average age at the last examination was 20 years (4-38); death occurred in two cases. The weakness was symmetrical and proximal. The period of worsening varied but, frequently, patients with a later onset of symptoms had a longer period of deterioration. Tongue fasciculations were present in all cases who never walked. Facial and masseter weakness occurred in 3 cases. Oesophagus dyskinesia and distension of the stomach due to brain stem lesions occurred in many cases. This brain stem damage was responsible of 2 sudden death (8-30 years). Premature pubarche occurred in 14 cases. Contractures with difformities were noted in all cases on non ambulatory children; Scoliosis appeared in 94% of them and in 60% of ambulatory children. Scoliosis prevention by orthosis and correction by othosis and surgical spinal stabilization was performed. The modalities of respiratory insufficiency were analyzed in non ambulatory children, the ratio between the measured vital capacity (V.C.) and the theorical vitral capacity (T.V.C.) fell during the growth; the VC remaining the same whatever the age is and respiratory failure occurred after puberty. Ventilation by oral positive pressure breathing was systematically performed to prevent this issue as soon as the disease was diagnozed. In ambulatory children the V.C. may decrease for a long time after the onset of the disease and respiratory insufficiency was always possible. Home assisted ventilation by endotracheal system was necessary in those cases. Results suggest the efficacy of early treatment on spinal impairment and respiratory insufficiency.