Scoliosis in Rett syndrome. Clinical and biological aspects.

Abstract

The natural history of progression of scoliosis was studied. The authors included a wide range of ages and correlated progression and progression rate to both age of the patient and the neurobiologic staging of the disease. The authors studied information compiled by Hagberg and coworkers regarding Rett syndrome. The total number of patients was 78, with age ranging from 1 to 34 years. Standing or sitting anteroposterior roentgenograms were collected and measured. The material was studied initially separately regarding orthopedic and radiologic analysis on one hand and neurobiologic staging on the other. Radiographic films were measured both retrospectively and prospectively, and scoliosis angle and progression and progression rate was calculated. Staging of patients with Rett syndrome was done according to Hagberg. When correlating curve magnitude and progression, the authors found that patients progressing > 15 degrees/year were classified as IV-A or IV-B stages. In the 0-5 year group, of the patients already having a curve of 15 degrees or more, all but one rapidly progressed to stage IV. The ten worst cases were characterized by early hypotonia, weakness, and gross motor disturbance. The scoliosis in Rett syndrome is of a neurogenic type, and it develops earlier than idiopathic scoliosis. The development of scoliosis is dependent more on stage of disease than on age. Curve progression is usually more rapid than in idiopathic scoliosis and in most other types of neurogenic scoliosis in childhood and occurs in a broader age span. Early hypotonia, weakness, and muscular insufficiency, and an early clinical referral to disease stages IV-A or IV-B are ominous factors. Clinical follow-up should begin early and be repeated regularly and frequently.