Abstract
Our objective was to investigate functional outcome in primary lateral sclerosis (PLS). We followed a group of 24 patients with PLS. Clinical (ALSFRS), respiratory, and neurophysiological (electromyography and transcranial magnetic stimulation) evaluations were performed at entry and regularly over the follow-up period. The time taken for a greater than 10% decrease in ALSFRS compared to the first assessment was defined as the dichotomous outcome; prognostic factors were evaluated using the Cox proportional hazard model. Results demonstrated that the median age at symptom onset was 54 years (range 28−75 years). In 46% symptoms began in the lower limbs, in 21% in the upper limbs and in 33% in bulbar muscles. The median symptom duration at first visit was 3.1 years (range 0.9−11.7 years). At last follow-up the median disease duration was 9.9 years (range 4.2−17.6 years). The median follow-up time was 4.6 years (range 2.1−11 years). We excluded from final analysis three patients with positive family history. Older age at onset (p = 0.019) was related to more rapid functional impairment; gender, forced vital capacity, region of onset and neurophysiological changes did not predict outcome. In conclusion, age is the most critical prognostic factor for functional outcome in PLS.
Acknowledgement
This work was supported by ‘Fundação para a Ciência e Tecnologia’(PIC/IC/82765/2007).
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.