Primary lateral sclerosis: Predicting functional outcome

Vânia Almeidaa, Mamede de Carvalho*abc, Manuel Scottod, Susana Pintob, Anabela Pintobe, Benjamim Ohanabe & Michael Swashbfa Department of Neurosciences, Hospital de Santa Maria-CHLN, Lisbonb Neuromuscular Unit, Instituto de Medicina Molecular − Faculty of Medicine of Lisbonc Institute of Physiology, Faculty of Medicine of Lisbond Department of Mathematics, University of Aveiro, Aveiro, Portugale Department of Medical Rehabilitation, Hospital de Santa Maria-CHLN, Lisbon, Portugalf Department of Neurology, Royal London Hospital, Queen Mary School of Medicine, University of London, London, UKCorrespondence: M. de Carvalho, Department of Neurosciences, Hospital da Santa Maria, Av. Prof. Egas Moniz, 1649-035 Lisboa, Portugal. Fax: +351217805219. E-mail: mamedemg@mail.telepac.ptAbstractOur 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.