Chronic REM sleep disorder may lead to neurodegenerative wake-up call

REM behavior disorder (RBD) is highly correlated with the development and progression of neurodegenerative disease including Parkinson’s, according to a brain study presented during the recent Society of Nuclear Medicine and Molecular Imaging 2014 Annual Meeting.

Longitudinal imaging data research conducted in part by Hongyoon Choi, MD, a PhD candidate from the department of molecular medicine and biopharmaceutical sciences at Seoul National University Bundang Hospital, Sungnam, Korea, indicate that idiopathic or iRBD is obviously linked to dopamine transporter system dysfunction.

“Our research using I-123 FP-CIT SPECT could provide direct evidence of longitudinal nigrostriatla degeneration in iRBD which is a core pathophysiology of Parkinsonian disorder,” said Choi. “Our approach is important for linking clinical findings and pathophysiology by using molecular imaging. Because I-123 FP-CIT SPECT can quantify the degree of nigrostriatal degeneration, a longitudinal follow-up in patients with iRBD was possible.”

For this study, a total of 21 subjects without any sign of Parkinsonism or cognitive decline underwent a baseline SPECT scan of dopamine transporter function with I-123 FP-CIT between 2004 and 2006 and then followed-up with another scan after close to 8 years to evaluate patients for advancement of neurodegenerative disease.

Neuroimaging data showed significant decreases in radiotracer binding to the dopamine transport system of the nigrostriatal area. Sluggish uptake here is positively associated with neurodegeneration and progression to dementia and movement disorders. A total of 10 out of 21 patients had lower striatal tracer binding at baseline and seven went on to full blown neurodegenerative disease by follow-up. A total of four patients developed Parkinson’s disease and two patients developed dementia with Lewy bodies.

“In the future, dopamine transporter imaging might predict subsequent Parkinsonian disorder in patients who have risk factors including iRBD,” suggested Choi.