Sporadic Spinal-Onset Amyotrophic Lateral Sclerosis Associated with Myopathy in Three Unrelated Portuguese Patients

Amyotrophic lateral sclerosis (ALS) and myopathy have been already described as part of a common genetic syndrome called multisystem proteinopathy. They may occur together or not, and can be associated with other clinical features such as frontotemporal dementia and Paget's bone disease. In addition, primary skeletal muscle involvement has been also reported in inherited forms of lower motor neuron disease, in spinal-bulbar muscular atrophy and in spinal muscular atrophy. We aim to characterize three sporadic, spinal-onset ALS patients, one with a concurrent non-specific myopathy, and two with a previous diagnosis of myopathy before upper and lower motor neuron signs emerged. Perhaps our sporadic ALS cases associated with myopathy share a common, but still unknown, pathogenic background. These cases raise the paradigm of a possible interplay between skeletal muscle degeneration and motor neuron damage.

Automated summary

Amyotrophic lateral sclerosis (ALS) and myopathy are part of a genetic syndrome called multisystem proteinopathy. They can occur together or separately, and may be associated with other clinical features. This study aims to characterize three sporadic ALS patients, one with concurrent myopathy and two with previous myopathy diagnoses before motor neuron signs emerged. These cases suggest a potential connection between skeletal muscle degeneration and motor neuron damage.