A Case Report of Solitary Sclerosis: This is Really Multiple Sclerosis.

Progressive solitary sclerosis is characterized by an isolated central nervous system demyelinating lesion arising in the spinal cord and brainstem, responsible for progressive motor impairment. We describe the case of a 40-year-old patient treated for more than 2 years with high doses of biotin (CERENDAY) for progressive symptoms of solitary sclerosis, who presented asymptomatic new T2 white matter lesions on brain magnetic resonance imaging (MRI). As there is no treatment option for solitary sclerosis, high doses of biotin were proposed, but had no impact on the progression of motor deficit. As the brain MRI showed no evidence of T2 lesions during the 10 years before the introduction of biotin, the demonstration of dissemination over time with this treatment raises questions. High doses of biotin have shown efficacy in some patients with spinal progressive MS, but could reveal a latent inflammatory condition.