MULTIPLE SCLEROSIS MSJ JOURNAL

There is increasing evidence that metabolic diseases involving the central nervous system may present with an adult onset and mimic degenerative or demy-elinating diseases.1 Another case is reported in this issue by Bottin et al. They describe the case of a 22-year-old man presenting with a subacute extensive myelopathy with bilateral optic neuropathy mimick-ing seronegative neuromyelitis optica. Metabolic evaluation revealed biotidinase deficiency, and treat-ment with high doses of biotin progressively improved the clinical condition. Very few cases of similar obser-vations have been previously reported in adolescents or children with biotinidase deficiency and, as stated by Bottin et al., it becomes increasingly important to include biotinidase assessment in patients with seron