Summary

We report a 55-year-old patient, presenting with paresis, muscle atrophy and dysarthria, all symptoms accordable to definite amyotrophic lateral sclerosis (ALS). However, MRI and cerebrospinal fluid show abnormalities typical of multiple sclerosis (MS). On the basis of this case report, we discuss possible overlaps between both diseases by comparing clinical and paraclinical features including laboratory, radiological and electrophysiological diagnostics. As genetic, as well as environmental, factors are assumed to be involved in the development of both the diseases, literature is reviewed according to similar cases, results of autopsies and possible parallels in pathogenesis. In summary, based on the data currently available, the hypothesis of ALS being a neurodegenerative multisystem disorder, a common pathophysiological pathway or, alternatively, a random comorbidity of ALS and MS in this patient has to be discussed.