Camptocormia in patients with multiple system atrophy at different disease durations: frequency and related factors.

BACKGROUND Camptocormia is common in patients with multiple system atrophy (MSA). The current study was aimed at assessing the frequency of camptocormia and its related factors in MSA patients with different disease durations. Also, the impact of camptocormia on disability was evaluated. METHODS A total of 716 patients were enrolled in the study. They were classified into three groups based on disease duration (≤ 3, 3-5, ≥ 5 years). Specific scales were used to evaluate the motor and non-motor symptoms. Disease severity was assessed using the Unified Multiple System Atrophy Rating Scale (UMSARS). The binary logistic regression model was used to explore the factors related to camptocormia. To analyze the impact of camptocormia on disability in patients with disease duration less than 5 years, propensity score matching (PSM) and stratified Cox regression analysis were used. RESULTS In the current study, we found that the frequency of camptocormia was 8.9, 19.7 and 19.2% when the disease duration was ≤3, 3-5, ≥ 5 years, respectively. In the disease duration ≤3 years group, we found that MSA-parkinsonian subtype (MSA-P) (OR = 2.043, P = 0.043), higher total UMSARS score (OR = 1.063, P < 0.001), older age of onset (OR = 1.047, P = 0.042), and lower score on the frontal assessment battery (FAB) (OR = 0.899, P = 0.046) were associated with camptocormia. Only greater disease severity was associated with camptocormia in the group of patients with disease duration 3-5 years (OR = 1.494, P = 0.025) and in the group of patients with disease duration ≥5 years (OR = 1.076, P = 0.005). There was no significant impact of camptocormia on disability in patients with a disease duration of < 5 years (HR = 0.687, P = 0.463). CONCLUSION The frequency of camptocormia increased with prolonged disease duration. Disease severity was related to camptocormia at different stages of the disease. The MSA-P subtype, older age of onset, and lower FAB score were associated with camptocormia in the early stage of the disease.