A patient with adult neuronal ceroid lipofuscinosis (ANCL; Kufs' disease) is described in whom neuroleptic malignant syndrome occurred, initially presenting as catatonic syndrome. Comprehensive neuroimaging studies were conducted including FDG-PET, IBZM-SPECT, and beta-CIT-SPECT, electrophysiological examinations and an ex vivo contracture test exposing muscle biopsy specimens to neuroleptics. Collectively the results argued for an involvement of the muscle in neuroleptic malignant syndrome at least in ANCL.