[Lewy body dementia: some contributions to the clinical knowledge]

Dementia with Lewy bodies is the second commonest type of dementia. The latest criteria for its diagnosis have recently been established (1996).

We report the clinical findings in 25 patients with probable dementia with Lewy bodies.

No sex predominance was seen, onset was after the age of 65 years in 60% of the cases and there was a past history of dementia in 48%. Onset was with cognitive disturbances in 32%, Parkinsonism in 32% and both in 32%. When there was an interval between Parkinsonism and dementia, this was of 3-19 months. The dementia included attention disorder, impaired recall and praxis alterations. Disorders of executive function, behaviour or language, were seen in two thirds of the patients and acalculia in over half. Around 50% showed signs of subcortical involvement different from Parkinsonism. Parkinsonism was basically hypokinetic (96%), with tremor in two thirds of the cases, at rest (29%) postural (12%) or combined (59%), and symmetrical in 41%. Rigidity was only seen in 52% and was slight in most cases. In 16% there was weakness of vertical gaze. In 40% urine or double incontinence occurred, mainly when the dementia was at an intermediate or advanced state.

Dementia with Lewy bodies is a dementia with fronto-temporo-parietal alterations, frequently associated with hypokinetic Parkinsonism (which always shows a lag period with respect to dementia of less than 24 months), hallucinations and a fluctuating course. Other findings supporting this diagnosis were seen in two out of every three patients.