Selected cognitive losses after stroke. Frequency, recovery and prognostic importance.

Data collected in a population-based study on 976 patients suffering an acute stroke have been analysed to discover the frequency of disturbance of selected cognitive functions, particularly orientation, non-verbal reasoning, and copying. Further analysis investigated how these deficits related to other impairments, their prognostic importance, and their recovery. Considering patients assessed within the first week, only 45% were orientated, only 44% could be assessed for IQ and their average score was 94 (SD 16), and only 36% could copy a cross satisfactorily. Seventeen per cent of patients had a reduced level of consciousness preventing assessment, and the other unassessable patients had other impairments such as aphasia preventing assessment. In general failure to pass these tests was associated with evidence of a more severe stroke; the patients had other impairments such as a more severe paralysis. No independent effect of cognitive dysfunction upon recovery could be demonstrated. By 6 months most surviving patients passed all the tests used.