Written by epgonline.org - Last updated 29 May 2018
This collection of diseases encompasses a wide range of conditions, categorised by their symptomatic impact upon the neurological system. Pathogenesis and epidemiology are highly variable; this group of diseases can present at any time from infancy through to old age.
It includes some of the lysosomal storage disorders, cerebellar disorders, movement disorders, muscle tone abnormalities and autonomic nervous dysfunction, among others.
Lysosomal storage disorders refer to a rare group of inherited diseases created by a missing step in an intracellular synthetic process. This causes an excess of metabolic by-products which can lead to mechanical distension, and subsequent destruction of neurones or other cells. Presentation is variable, but typically affects infants, resulting in death at a young age. Learn more about the lysosomal storage disorder nephropathic cystinosis in our Nephropathic Cystinosis Knowledge Centre.
Cerebellar disorders include any disease primarily manifesting with cerebellar signs and symptoms. These typically include: truncal or gait-related ataxia, dysdiadochokinesis, nystagmus, dyssynergia, dysarthria, tremor and hypotonia.
Muscle tone abnormalities have some overlap with cerebellar and movement disorders, however the symptoms of acute dystonias and hereditary spastic paraplegias are primarily related to hypertonia or spasticity.
Movement disorders encompass disease-states that result in abnormal movements such as chorea, akathisia, or tremor, while including reduction of movement, such as motor-neurone diseases or striatonigral degeneration (excluding Parkinson’s disease). This can be due to any aetiology, including drugs.
Autonomic dysfunction in this group often relates to dysregulation of blood pressure. This can lead to syncopal episodes, in the case of carotid sinus syndrome, or more severe autonomic hyperstimulation, in the case of autonomic dysreflexia.