Progressive neurologic dysfunction in a psoriasis patient treated with dimethyl fumarate.
Bartsch T, Rempe T, Wrede A et al.
University Hospital of Schleswig-Holstein, Kiel, Germany.
Ann Neurol 2015;78:501–14.
Stefan Bittner’s review: Bartsch and colleagues report on a patient with psoriasis who developed progressive multifocal leukoencephalopathy (PML) during treatment with dimethyl fumarate (DMF). The patient had slowly progressing clinical deficits starting with facial dysesthesia and evolving into left hemisensory dysfunction, predominantly left-sided tetraparesis, ataxia, brainstem signs, and focal motor seizures over a period of 2 years. Serial magnetic resonance images paralleled the clinical disease course, revealing a slowly enlarging T2 hyperintense lesion within the right thalamus that expanded into the internal capsule, the brainstem, and the frontoparietal lobes. Extensive laboratory and radiological testing did not reveal any conclusive findings and a JC virus (JCV) polymerase chain reaction using a cerebrospinal fluid sample was negative. Finally, a brain biopsy led to the diagnosis of PML. Fumarates were then ceased and treatment with mirtazapine and mefloquine was initiated. The clinical and radiological disease course stabilized after 4 months of this treatment. This case is informative and instructive for daily clinical practice as well as for future research efforts.