Drug Induced Parkinsonism Caused by the Concurrent Use of Donepezil and Risperidone in a Patient With Traumatic Brain Injuries
A 69-year-old male patient with decreased mental status and headaches after falling down the stairs visited our emergency room on around February 2010. His muscle strength was relatively preserved over a good grade on his all extremities. On the computer tomography of his brain, subdural hemorrhage on the right parietal lobe and the left frontal lobe, subarachnoid hemorrhage on the bilateral temporal lobe, and fracture on the right parietal bone were found (). The diagnosis of TBI was confirmed. He was admitted to the Department of Neurosurgery for a conservative treatment, and his mental status was gradually improved from stupor to alert. He started his rehabilitation therapy including proper evaluations from 2 weeks after the injury. On functional evaluation, he could not sit alone nor stand without assist, and these disabilities could not be ruled out from poor corporations or decreased muscle strength. Three weeks after injury, he was transferred to the rehabilitation department, and he started cognitive rehabilitation program. On 5 weeks after injury, his cognitive function was markedly improved, and his Korean Mini Mental State Examination (MMSE-K) score was 21. His functional level was improved accordingly, and Korean Modified Barthel Index (K-MBI) score was improved from 2 to 81. On 6 weeks after injury, we could evaluate his muscle strength precisely, and all his extremities showed over the good grade on manual muscle test. He was able to walk independently, and was discharged.\nHe received the rehabilitation therapy as an outpatient until 8 weeks after injury, and then he was encouraged to exercise alone at home receiving only outpatient follow-up. However, during staying in his home without serial rehabilitation therapy, his personality took on aggressive and delusional characteristics. His cognitive impairment and aggressive behavior got worse, and he was admitted to the Department of Neuropsychiatry with diagnosis of the delusional disorders on 3 months after his first discharging from the hospital. At the time he was hospitalized again, no auditory or visual hallucination was found; however, he appeared to have anxiety, delusion, and aggressive behavior. The magnetic resonance image (MRI) of his brain showed no additional lesion than the chronic changes from hemorrhages on bilateral cerebral hemisphere of his previous TBI. Accordingly, with the diagnosis of delusional disorder which occurred after TBI, he was treated with 2 mg of risperidone per day. After starting this medication, his delusion, anxiety, and aggressive behavior gradually improved enough to cooperate with the therapists. Two weeks later, he was given 10 mg of donepezil per day for his mild cognitive impairment. After 6 weeks of admission in the Department of Neuropsychiatry, he was transferred to the Department of Rehabilitation for the proper rehabilitation therapy, because he showed problems in his gait. He could walk independently, but he showed no movements in his upper extremities and his step-width was narrow. Additionally, he had scooped posture, bradykinesia, tremor in both hands, and sleep disorder. He complained of difficulty in walking, and he could not start any movement promptly. He had difficulties in all activities of daily living, and K-MBI score was 56/100. These symptoms were characteristics of Parkinsonism, and we assumed that this parkinsonian features were related with the administration of risperidone and donepezil, which were started before the onset of his parkinsonian features. Therefore, dopamine transporter imaging with [18F]FP-CIT PET-CT was performed to distinguish his parkinsonian features from idiopathic Parkinson's disease, and normal dopamine transporter density was observed in bilateral caudate nucleus and putamen (). With this result, we could exclude idiopathic Parkinson's disease, and we diagnosed his parkinsonian features as drug-induced Parkinsonism caused by concurrent use of risperidone and donepezil. We discontinued both donepezil and risperidone, and the parkinsonian features gradually disappeared. He was discharged with much improved functions, and K-MBI score was 75.