Strategic sequence planning and prospective memory impairments in frontally lesioned head trauma patients performing activities of daily living

The aim of this research was to study strategic sequence planning and prospective memory in activities of daily living (ADL) in 10 patients with frontal lobe lesions after a mild to moderate closed head injury (CHI). The lesions were documented radiologically. The CHI patients were compared to 12 normal controls with a neuropsychological test battery and a realistic simulation of complex multitask ADL (planning and preparing a meal). Though the CHI patients were significantly slow on one test and subject to interference on an attention test, they manifested no basic executive or memory deficit on the paper-pencil tests. However, the CHI patients manifested marked anomalies in the organization of behavior in the meal preparation task. While small sequences of actions were easily produced, large action sets could not be correctly executed. An outstanding difficulty in strategic planning and prospective memory, particularly time-based more than event-based, appears to be an important underpinning of the impairment of ADL observed in the CHI patients with frontal lobe lesions.