Primary central neurons system lymphoma presenting with a parkinsonian syndrome of pure akinesia

The incidence of primary central nervous system lymphoma (PCNSL), once a ra n tumour, has risen significantly in both immunocompetent and immunosuppres sed patients. Although infiltration of the basal ganglia is not uncommon in PCNSL, extrapyramidal movement disorders an generally not recognised as a mode of clinical presentation of this type of cerebral tumour. We present t he unusual case of a 75-year-old man who developed a parkinsonian syndrome of "pure akinesia" due to autopsy-confirmed PCNSL primarily involving the g lobus pallidus bilaterally. Parkinsonism due to bilateral pallidal lesions is known but rare, and such cases help in the understanding of basal gangli a function with regard to akinesia and freezing.