Comorbidities in spinal muscular atrophy and their impact on the course of the underlying disease: a real-life observational study.

BACKGROUND

The lack of the SMN protein in SMA affects different tissues and organs, not only alpha motoneurons; this creates a broad spectrum of potential concomitant diseases, making SMA a multidisciplinary problem. This study focuses on an analysis of comorbidities, and their frequence and severity in SMA.

METHODS

The study group consisted of 55 patients, 25 women and 30 men, with genetically confirmed SMA types 2, 3a, and 3b. A medical history focused on comorbidities and a neurological examination with the evaluation on the extended Hammersmith Functional Motor Scale (HFMSE). The prevalence and severity of comorbidities were assessed using the Cumulative Illness Rating Scale (CIRS).

RESULTS

SMA type 2 was associated with the highest mean number of comorbidities and CIRS scores. All patients with type 2 had scoliosis. When scoliosis was not included in the analyses, there were no significant differences in the prevalence of comorbidities and CIRS scale scores between the SMA groups. CIRS scale scores with and without scoliosis were significantly higher in patients with low HFSME scores. Male patients had a greater tendency to develop lithiasis.

CONCLUSIONS

Scoliosis is a major factor that has an influence on the clinical course of SMA and on patients' overall condition. Other comorbidities are similar in all types of SMA. Comorbidities are more frequent and have a greater impact on the general condition in patients with more severe disabilities. The current difference between the sexes is the higher incidence of lithiasis and overweight in men.