Differentiation of the common dementias

Abstract

Abstract With the greying of society, diseases causing dementia are now recognized as being one of the most important challenges facing western medicine in the 21st century. The term ‘dementia’ describes a syndrome of acquired loss of cognitive function, behavioural changes, and loss of social function. There is no implied aetiology for dementia and most broadly it represents a neuro-behavioural syndrome that occurs in a large number of diseases. Most dementias occur on the basis of primary degenerative disorders of the central nervous system, though some occur with multisystem inflammatory diseases, infectious diseases, or metabolic/endocrine disorders. Surgically treatable dementias account for a very small percentage of all cases. The potential reversibility of dementia has been emphasized, though longitudinal studies from dementia clinics have demonstrated that in practice this is seen in only 3 to 8 per cent of cases (Clarfield 1988). In patients with dementia associated features such as depression, toxicity related to medications and metabolic disorders are the most frequently modifiable/ reversible problems (Clarfield 1988). The course of dementia is quite variable, though most typically a progressive declining disorder is seen. However, with careful workup and management of treatable components of dementia patients may live with an optimal level of function through their illnesses. The broadest goal for each dementia clinic, community based team, and individual practitioner should be to diagnose and manage each individual to their best level of cognition, behaviour, and function.