title: Three Cases of Levodopa-Resistant Parkinsonism After Radiation Therapy.
abstract: 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.
authors.affiliation: Department of Neurology, University of Texas Health Science Center, Houston, TX, USA
authors.forename: Raja
authors.initials: R
authors.lastname: Mehanna
authors.affiliation: Department of Neurology, Parkinson’s Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, TX, USA
authors.forename: Joohi
authors.initials: J
authors.lastname: Jimenez-Shahed
authors.affiliation: Department of Neurology, Center for Neurological Restoration, Cleveland Clinic Foundation, Cleveland, OH, USA
authors.forename: Ilia
authors.initials: I
authors.lastname: Itin
mesh_terms: D000328:Adult; D000368:Aged; D000978:Antiparkinson Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000532:radiotherapy* / Q000628:therapy; D002648:Child; D004351:Drug Resistance / Q000528:radiation effects; D005260:Female; D006801:Humans; D056784:Leukoencephalopathies / Q000209:etiology; D007980:Levodopa / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D020734:Parkinsonian Disorders / Q000188:drug therapy / Q000209:etiology*; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects*; D017211:Treatment Failure
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa