ISSN 1941-5923


Three Cases of Levodopa-Resistant Parkinsonism After Radiation Therapy

Raja Mehanna, Joohi Jimenez-Shahed, Ilia Itin

(Department of Neurology, University of Texas Health Science Center, Houston, TX, USA)

Am J Case Rep 2016; 17:916-920

DOI: 10.12659/AJCR.900537

Published: 2016-12-02

BACKGROUND: Unequivocal brain radiation-induced parkinsonism has so far been reported in only in two pediatric patients. However, with the rising incidence rates for brain tumors in industrialized countries and the consequential increased exposure to cranial radiotherapy, clinicians might become more exposed to this entity.
CASE REPORT: Three patients were treated for intraparenchymal brain tumor with resection, chemotherapy, and whole brain radiation. One patient developed leukoencephalopathy and parkinsonism within one year of treatment, one developed it seven years after treatment completion, and one developed dementia, parkinsonism and cerebral infracts 40 years after whole brain radiation. Brain MRIs and a DaTscan were obtained. All patients failed a trial of carbidopa/levodopa. We suggest that the brain radiation exposure was responsible for levodopa resistant parkinsonism, cognitive decline, and diffuse leukoencephalopathy.
CONCLUSIONS: Although rare, radiation therapy-induced parkinsonism might be responsible for levodopa-resistant parkinsonism.

Keywords: Abnormalities, Radiation-Induced, Leukoencephalopathies, Parkinsonian Disorders