Targeting Monoaminergic Neuronal Networks in the Parkinsonian Patients After Carbon Monoxide Intoxication

The study purpose is to determine the clinical values of 18F-FP-(+)-DTBZ in the diagnosis of Parkinsonism in patients with carbon monoxide intoxication, regional distribution and its correlation with clinical parameters. This study is expected to be completed in a period of 3 years.

With the urbanization of Taiwanese society, there are increasing numbers of people committing suicide by charcoal burning, making carbon monoxide (CO) encephalopathy a new pandemic phenomenon. In CO related parkinsonism, the clinical features included gait disturbances, mask face, rigidities and small steps. From literature searches, the CO related parkinsonism is related to white matter damages or decline in dopamine innervations. From our previous research results, the CO related neuronal damages would started from reversible or progressive white matter demyelination. For some patients, axonopathy or gray matter atrophy developed and became irreversible. The neuronal networks in determining development of Parkinsonism required to be established. In terms of neurotransmitter, most of the clinical data for Parkinsonism came from studies of idiopathic Parkinson's disease while the data of CO related Parkinsonism were limited to case reports. From neuropathology studies in idiopathic Parkinson's disease, dopamine deficits and decreased in monoamine transporters were observed well before the development of clinical features. Although there is linkage between CO related Parkinsonism and dopamine deficits, patients with CO intoxication had poor response to levodopa. The observation suggested the critical networks and neurotransmitters were still not well understood. 18F-FP-(+)-DTBZ is a newly developed nuclear medicine tracer for monoamine transporter. The study purpose is to determine the clinical values of 18F-FP-(+)-DTBZ in the diagnosis of Parkinsonism in patients with carbon monoxide intoxication, regional distribution and its correlation with clinical parameters. This is a three-year prospective research. For each patient, the PET will be arranged twice, with an interval of 18 months. The regional distribuation of 18F-FP-(+)-DTBZ in relation to Parkinsonism severity and regional reduction patterns longitudially will be assessed in order to understand the regional neurotoxicity and the functional progression.