Do aetiology, age and cogntive reserve affect executive performance?

Background: The behavioral effect of frontal lesions may beinfluenced by confounding factors such as aetiology, age and cogntivereserve. Yet no studies have investigated their effects on patients withfocal lesions.Objective: Is the grouping of patients with frontal lesions caused bystroke or tumours methodologically appropriate; does age affectcognitive performance, can cognitive reserve protect against cognitiveimpairment?Patients and Methods/Material and Methods: Cognitive performancewas compared across a large sample of frontal patients withstroke, high or low grade tumour, or meningioma. The effect of age,education and NART IQ on the cognitive performance of patientswith focal lesions was investigated. Assessments of lesion location,volume, global brain atrophy and non-specific white matter changeswere undertaken.Results: No significant difference in cognitive performance betweenthe different aetiologies was found. Age of frontal patients significantlypredicted the magnitude of their impairment on executive butnot on nominal or perceptual tasks. In contrast, non frontal patients'age did not predict the magnitude of their impairments. Afteraccounting for chronicity, age and severity of frontal lesion, NART IQcontributed to performance on the executive and naming tests whilsteducation contributed to fluid intelligence. The interactions betweenlesion severity and our CR proxies were not significant.Conclusion: The grouping of patients with frontal lesions caused bydifferent aetiologies is a justified methodology that helps to furtherthe understanding of frontal executive functions. The frontal cortexplays a critical role in aging to counteract cognitive and neuronaldecline and when lesioned greater cognitive reserve does not betterwithstand neuropathology.