Neuroimaging in Parkinson's disease

Abstract

In this review, the potential role of positron emission tomography and single photon emission computed tomography as biological markers for diagnosing and following the progression of Parkinson's disease (PD) is discussed. Their value for assessing the efficacy of putative neuroprotective agents in PD and for revealing the pharmacological changes underlying the symptomatology and complications of this disorder is also considered. It is concluded that in the future functional imaging will provide a valuable adjunct to clinical assessment when judging the efficacy of putative neuroprotective approaches to PD.

FIG. 1.

¹⁸F-dopa PET. ¹⁸F-dopa uptake in a normal subject and early hemi-PD patient. The PD patient shows bilateral posterior putamen loss of signal. Statistical parametric mapping localizes significant reductions in ¹⁸F-dopa uptake in the caudate and putamen contralateral and the posterior putamen ipsilateral to the affected limb in a group of hemi-PD cases (picture courtesy of J. Rakshi, MRC Clinical Sciences Center and Division of Neuroscience, Faculty of Medicine, Imperial College London, UK).

FIG. 2.

Increased nigral and pallidal microglial activation in substantia nigra and pallidum, revealed by ¹¹C-PK11195 PET in PD (picture courtesy of A Gerhard, MRC Clinical Sciences Center and Division of Neuroscience, Faculty of Medicine, Imperial College London, UK).

FIG. 3.

SPM findings in the REAL-PET trial. Significant 2-year reductions in putamen and nigral ¹⁸F-dopa uptake localized by SPM in cohorts of PD patients receiving either ropinirole or levodopa.

FIG. 4.

Striatal and thalamic NK1 binding of ¹⁸F-L829165 in nondyskinetic and dyskinetic PD patients. Thalamic signal is reduced in the latter (picture courtesy of A. Whone, MRC Clinical Sciences Center and Division of Neuroscience, Faculty of Medicine, Imperial College London, UK).