How Reversible are ‘˜Reversible Dementias’?
Reversible dementias comprise different groups of disorders of variable aetiologies, such as structural brain lesions or metabolic, infectious, toxic, autoimmune, paraneoplastic and psychiatric disorders. When patients present with cognitive symptoms, especially in the younger age groups, the first thought of the attending neurologist should be to try to identify an underlying treatable cause. The incidence of degenerative dementia rises with older age and its symptoms progressively become more evident and typical; in such cases, a differential diagnosis is limited and the chance of uncovering a treatable disorder is minimal. However, although uncommon, treatable dementias or dementia-like symptoms do exist. Future studies with better design and methodology, as well as longer observation periods and larger patient populations, are needed to clarify the controversial issues concerning the epidemiology and accurate diagnosis of, and treatment possibilities for, reversible dementias.