Prognostic Factors in Sporadic Bulbar Onset Motor Neuron Disease

Objective To identify possible prognostic factors of sporadic bulbar onset motor neuron disease (MND). Methods Our study involved bulbar onset MND patients between January 2014 and December 2023. Decease, tracheotomy and permanent non-invasive positive pressure ventilation were defined as endpoint events. Clinical data were retrospectively collected, cut-off values of duration from onset to next region were calculated for further evaluation of its prognostic effect and disease classification. Results A total of 537 patients initially met eligibility and 441 of them were routinely followed up, 213 cases reached endpoint events. Female versus male ratio was 1.22, and median age at onset was 57 years. Median duration from onset to next region and onset to endpoint events were 6 months and 29 months respectively. Lower age at onset, slower ALSFRS-R decreasing rate, longer duration from onset to next region and pure upper motor neuron (UMN) involvement at first visit were associated with favorite prognosis. Cut-off values of duration from onset to next region were defined as 7 and 10 months respectively for patients with and without lower motor neuron (LMN) involved. Conclusions We identified age at onset, duration from onset to next region, ALSFRS-R decreasing rate and exclusive UMN involvement at first assessment as possible prognostic factors. A classification diagram for bulbar onset MND was proposed based on patterns of UMN and LMN involvement and duration from onset to next region.