Neurodegenerative dementia and parkinsonism.

BACKGROUND: Dementia and Parkinsonism are two major neurodegenerative disorders. Accurate diagnosis can be difficult when patients have both syndromes because of a wide range of etiologies. OBJECTIVES: To improve clinical diagnosis, we propose a disease classification based on the pathological proteins which are involved in the neuropathological disease process. DESIGN: Four neuropathological classes are proposed based on four major proteins, tau, A beta, alpha -synuclein and TDP43 : 1/ Tauopathy and amyloidopathy with possible Parkinsonism, 2/ Tauopathy with predominant Parkinsonism, 3/ Synucleinopathies with cognitive impairment/dementia and 4/ The TAR DNA binding protein 43 (TDP-43). This classification raises certain questions in clinical practice due to intriguing overlaps between clinical presentations despite the same pathological protein being involved. CONCLUSION: The development of molecular and pathological protein research in neurodegenerative disorders can help classify the clinical association of dementia and Parkinsonism and improve therapeutic strategies against proteins involved in the degenerative process.