In the last few years, research has been focussed on the identification and quantification of dopaminergic and non dopaminergic lesions in Parkinson’s disease and Parkinsonism and on the direct MRI localization with greater individual accuracy of therapeutic targets for deep brain stimulation (i.e. the sub-thalamic nucleus (STN) and a promising new target such as the pedunculopontine nucleus (PPN) (Plaha P et al 2005; Stefani et al 2007; Zrinzo et al 2008).
As a consequence, imaging of the brainstem nuclei has become both of therapeutic and physiopathologic interest with a need to develop new and powerful imaging techniques. Moreover, in light with the neuropathology Braak’s staging (Braak H et al 1996), a special interest on non motor signs in Parkinson’s disease (as for example REM sleep behaviour disorders -RBD-) has developed. Indeed, RBD may be predictive of the appearance of motor signs of Parkinsonism, but they may also be predictive factors of the evolution of Parkinson’s disease (e.g. RBD predictive of cognitive changes especially in executive or visuo-spatial or visuocontructive functions).
If neuroprotective or neuromodulating agents or techniques were available in the near future, the identification and hopefully the quantification of the abnormalities of the brain structures may help to establish a therapeutic strategy as the early stage of the disease or give some clues of the progressive pattern of the disease.