Cerebrotendinous xanthomatosis presenting with asymmetric parkinsonism: a case with I-123-FP-CIT SPECT imaging.

Cerebrotendinous xanthomatosis (CTX) is a rare inherited neurometabolic disease. Clinical symptoms are caused by increased deposition of cholestanol and cholesterol in various tissues. Progressive neurological symptoms are one of the principal manifestations. We report the case of a 44-year-old man who presented with asymmetric parkinsonism. In addition, there were mild bilateral pyramidal signs and a mild polyneuropathy. Brain MRI showed bilateral lesions in the dentate nucleus of the cerebellum and in the substantia nigra. Nuclear brain imaging using I-123-FP-CIT demonstrated an asymmetric reduced presynaptic dopaminergic function of the putamen and caudate nucleus, correlating well with his lateralized bradykinetic-rigid syndrome. CTX was diagnosed based on an increased plasma level of cholestanol, typical cerebellar brain lesions and the causative genetic mutation. CTX presenting with parkinsonism is considered rare and data on the neuroimaging of the dopaminergic deficit are limited.