Disrupted identities: movement, mind, and memory in Parkinson's disease.

For the many clinicians au fait with the history of the clinical description of Parkinson's disease, they will be aware that the very earliest description of James Parkinson's "Shaking Palsy" in 1817 explicitly excluded the involvement of cognitive and emotional processes as manifestations of the disease. Within a short time following his treatise, it became all too clear to those in the field that Parkinson's disease is more than just a motor disorder, and as was aptly conceptualized by Paul McHugh, Professor of Psychiatry at Johns Hopkins Hospital from 1975 until 2001, Parkinson's disease is closer to being a "triadic disorder," encompassing motor, cognitive, and psychiatric elements (McHugh, 1989). Even this notion is now outdated, with the triad being accompanied by autonomic, pain, and other non-motor syndromes.