Dopamine transporter imaging with [123I]-β-CIT demonstrates presynaptic nigrostriatal dopaminergic damage in Wilson’s disease
- aDepartment of Neurology and Nuclear Medicine, bCollege of Medicine, Seoul National University, Seoul National University Hospital, Seoul, Korea
- Dr B Jeon, Department of Neurology, Seoul National University Hospital, Seoul 110–744, Korea. Telephone 0082 2 760 2876; fax 0082 2 760 3255; email jeonmd{at}plaza.snu.ac.kr
- Received 7 July 1997
- Revised 20 October 1997
- Accepted 3 December 1997
Abstract
OBJECTIVES The most common neurological manifestations in Wilson’s disease are parkinsonism and dystonia. These are assumed to be due to striatal injury, which has been repeatedly demonstrated by pathology and CT or MRI. The substantia nigra has not been shown to be damaged in pathological studies. However, there have been clinical and imaging studies suggesting presynaptic nigrostriatal injury. (1r)-2β-carbomethoxy-3β-(4-iodophenyl)tropane (β-CIT) is a specific ligand that binds to the dopamine transporter (DAT), and can examine the integrity of dopaminergic nerve terminals. Evidence for presynaptic nigrostriatal dopaminergic damage in Wilson’s disease was searched for using [123I]-β-CIT SPECT.
METHODS Six patients with Wilson’s disease were studied, together with 15 healthy normal controls, and six patients with Parkinson’s disease. After injection of [123I]-β-CIT, SPECT studies were done at 18 hours. Specific striatal/occipital binding ratio (S/O ratio) was calculated as (striatal binding−occipital binding)/occipital binding.
RESULTS The specific S/O ratios were 6.22 (1.32) (mean (SD)) in normal volunteers, 3.78 (0.65) in Parkinson’s disease, and 3.60 (0.49) in Wilson’s disease.
CONCLUSION There was severe loss of the DAT in the striatum suggesting significant damage in presynaptic nigrostriatal dopaminergic nerve terminals. Therefore, a presynaptic lesion may contribute to neurological manifestations in Wilson’s disease.
