Parkinson's Disease

Introduction

Parkinsonism encompasses a variety of syndromes and disorders of varying aetiologies and falls broadly into three categories:

• Parkinson’s disease (PD)
• Parkinson’s-Plus (PD-Plus) disorders
• Secondary Parkinsonism

Parkinsonism disorders are progressive degenerative disorders of the central nervous system, which are clinically characterised by dysfunctional motor control and caused by the loss of dopamine- and noradrenaline-producing neurons  in the basal nuclei  and locus coeruleus  of the brain.

The main focus of this area of the Brain Explorer will be on the clinical management and prognosis of PD. However, effective management and a favourable prognosis depend on the correct differential diagnosis of PD, which in turn depends upon accurate identification of the underlying causes of the signs and symptoms of PD.

Approximately 80% of Parkinsonism is due to PD, named after James Parkinson who gave the first cogent description of the syndrome in 1817. Some years later (1841), Marshall Hall referred to the syndrome more descriptively as the paralysis agitans. These early descriptions focus on muscular stiffness and rigidity coupled with tremor . In 1860, Charcot suggested the name ‘la maladie de Parkinson‘.

It is worth noting that the terminology of Parkinsonism is not wholly consistent across the globe. For example, Parkinson syndrome, Parkinsonism or Atypical Parkinson’s disease may be used synonymously with Parkinsonism or alternatively to describe a case that is not PD, but is more like PD than one of the PD-Plus disorders. When dealing with people with suspected PD, it is desirable to restrict the use of the term ‘Parkinson’s disease’ to those cases where the diagnosis is at least highly probable.