• Introduction

• Epidemiology

• Symptoms

• Pathology

• Aetiology

• Overview

• Pharmacological

• Other methods

Note: This section of the site is aimed primarily at laypeople. The introduction gives a general overview of PD and Parkinsonism, while the subsections provide more detail about various aspects of the disease. Clicking on any of the underlined terms will take you to the relevant glossary entry. Alternatively, see the Glossary for an alphabetical list of potentially unfamiliar terms used in this document.

Introduction

Parkinson's disease (PD) is a progressive neurodegenerative disease belonging to the class of disorders collectively known as "synucleinopathies". It is primarily a movement disorder, characterised by signs such as tremor, slowness of movement (bradykinesia), rigidity and postural abnormalities. However, a subset of patients (about 30 to 60%) also develop mental symptoms, most notably dementia. Characteristic neuropathology includes the specific loss of neurons from a region of the midbrain (the substantia nigra pars compacta) involved in the control of movement. This neuronal loss, together with the presence of abnormal eosinophilic protein inclusions called Lewy bodies, is diagnostic for the disease.

The disease, which occurs worldwide, is the most common degenerative disorder of the motor system and, after Alzheimer's disease, the second most common neurodegenerative disorder. It is generally seen as a disease of the elderly: in the UK, about 1% of those over 65 are sufferers, compared with 1 in 1000 of the general population. However, younger people can — and do — develop the disorder: about 10% of PD patients are diagnosed below the age of 40 (so-called "young-onset PD"). It is important to note that, although age is a significant risk factor, the disease symptoms are not part of the normal aging process. According to some studies, incidence appears to vary between the genders, with 3 men affected for every woman diagnosed.