The Frontal Lobe Score: part I: construction of a mental status of frontal systems.

Objective: To develop a bedside mental status examination to assess the behavioural effects of damage to the frontal lobes.

Design: A prospective clinical comparison of patients with cerebral lesions of different locations.

Subjects: A total of 118 subjects were examined: 27 patients with cerebral lesions confined to the frontal lobes, 25 patients with cerebral lesions without involvement of the frontal lobes, 18 patients with mixed frontal/nonfrontal lesions, and 48 normal control subjects.

Measures: Twenty-three mental status tests, clinical examinations and rating scales that had been reported as indicative of frontal lobe function were brought together. By statistical analysis, 12 tests and a neurobehavioural rating scale were selected. These constitute the Frontal Lobe Score (FLS).

Results: The FLS detected pure frontal lesions with a sensitivity of 77.7%. It discriminated patients with frontal lesions from normal control subjects with a specificity of 100%. Differentiation from patients with nonfrontal lesions was obtained with a specificity of 84%.

Conclusion: The Frontal Lobe Score is a useful screening instrument for the clinical detection of effects of frontal lobe damage.