The impact of upper motor neuron involvement on clinical features, disease progression and prognosis in amyotrophic lateral sclerosis

Objectives In amyotrophic lateral sclerosis (ALS) both upper (UMNs) and lower motor neurons (LMNs) are involved in the process of neurodegeneration, accounting for great disease heterogeneity. We evaluated associations burden UMN impairment, assessed through Penn Upper Motor Neuron Score (PUMNS), with demographic clinical features ALS patients to define independent role involvement generating heterogeneity, predicting progression prognosis. Methods collected following parameters on a cohort 875 patients: age site onset, survival, MRC scale, neuron score (LMNS), PUMNS, ALSFRS-R, change ALSFRS-R over time (DFS), MITOS King’s staging systems (KSS). Transcranial magnetic stimulation was performed subgroup central conduction (CMCT) cortical silent period (CSP) were calculated. Results observed that an earlier at onset bulbar had higher PUMNS values. Higher values also associated DFS scores, as well KSS, indicating greater correlates severity. Conversely, we did not appreciate any association between survival or markers LMN impairment. Moreover, showed positive CMCT negative one CSP Interpretation Our results suggest pathology, has important defining characteristics, functional disability, prognosis patients. support TMS severity involvement.