Patterns of symptom development in patients with motor neuron disease

AbstractObjective: To investigate whether symptom development in motor neuron disease (MND) is a random or organized process. Methods: Six hundred patients with amyotrophic lateral sclerosis (ALS), upper motor neuron (UMN) or lower motor neuron (LMN) phenotypes were invited for a questionnaire concerning symptom development. A binomial test was used to examine distribution of symptoms from site of onset. Development of symptoms over time was evaluated by Kaplan-Meier analysis. Results: There were 470 respondents (ALS = 254; LMN = 100; UMN = 116). Subsequent symptoms were more often in the contralateral limb following unilateral limb onset (ALS: arms p = 1.05 × 10−8, legs p < 2.86 × 10−15; LMN phenotype: arms p = 6.74 × 10−9, legs p = 6.26 × 10−6; UMN phenotype: legs p = 4.07 × 10−14). In patients with limb onset, symptoms occurred significantly faster in the contralateral limb, followed by the other limbs and lastly by the bulbar region. Patterns of non-contiguous symptom development were also reported: l...