Abstract
The aim of our study was to analyse the natural history and clinical features of upper motor neuron- dominant (UMN-D) ALS. We studied a large series of sporadic ALS patients admitted in a single referral centre over a 23-year period. UMN-D phenotype was compared with other ALS forms, including classic ALS, flail arm and progressive muscular atrophy. Seven hundred and thirty-four sporadic ALS patients were included of which 163 had UMN-D ALS. The mean age of onset in UMN-D ALS (52 years) was 10 years lower than in classic ALS (61.4 years, p < 0.0001); sex ratio by age groups significantly differed with respect to other phenotypes. The pattern of spread of lower motor neuron signs in UMN-D was characterized by early involvement of upper limb muscles and late impairment of respiratory muscles. Duration of the disease was longer in the UMN-D group (56 months) than in classic ALS (33 months, p < 0.001). The UMN-D phenotype was a strong independent predictor of long survival. In summary, UMN-D ALS showed significant differences in age of onset, sex ratio, pattern of spreading and prognosis with respect to other ALS forms, most probably reflecting biological differences.
Acknowledgement
We thank patients and their families for contributing to this study. ICOMM Association for ALS Research and Federazione Italiana Giuoco Calcio funded genetic studies.
Declaration of interest: The authors declare no conflict of interests.