Infantile spinal muscular atrophy in 39 children / 中华实用儿科临床杂志

ABSTRACT

Objective To improve the recognition for infantile spinal muscular atrophy (SMA-Ⅰ) and the level of early diagnosis,intervention and treatment for SMA-Ⅰ.Methods The clinical data of 39 patients with SMA-Ⅰ were analyzed retrospectively, including the clinical manifestations, neural electrophysiological characteristics, geno-type, diagnosis,treatment and prognosis of SMA-Ⅰ.Results Of the 39 cases with SMA-Ⅰ , 37 cases (94.9％) had onset in 6 months after birth.The paralyses of the limbs were symmetrical and flaccid.The lower was more severe than the upper , and the proximal was more severe than the distal, hypotonia and tendinous reflex disappears.Thirty-two cases (82.1％) had normal serum creatine kinase, and 7 cases (17.9％) increased slightly.Nerve electrophysiological examination showed that 169 (96.0％) had spontaneous potentials in 176 muscles.Of 160 limb muscles,35 (21.8％) released few motor unit potential (MUP) ,117 (73.1％) extended the duration of MUP and 104 (65.0％) increased the amplitude of M UP.Of 167 peripheral motor nerves, 160 (95.8％)decreased the amplitude of the compound muscle action potential and 162 (97.0％) had normal motor conduction velocity.Of 93 peripheral sensory nerves, 93 (100.0％) had normal range of the conduction.The gene detection showed that 38 cases had homozygous deletion of exon 7,8, and 1 case had homozygous deletion of exon 7 and heterozygous deletion of exon 8.In the effective follow-up of 30 cases,6 cases died in the 2-3 months after birth,4 cases died in 10 months after birth, 12 cases died in 12-18 months after birth.Six cases survived to 2 years old,2 cases survived to 3 years old,and all of them died of pulmonary infection.Conclusions There are typical clinical and nerve electrophysiological characteristics for SMA-I.Nerve electrophysiological examination can be used as an important method for diagnosis and differential diagnosis for SMA-I.Genetic testing can be used to identify the disease and make prenatal diagnosis.Through comprehensive intervention the quality of life can be improved in SMA-Ⅰ children.