Relationship of frontal lobe dysfunction and aberrant motor behaviors in patients with Alzheimer's disease.

BACKGROUND: In order to address the neuropsychological pathogenesis of aberrant motor behaviors in Alzheimer's disease (AD), we used a cross-sectional study design to investigate the association between frontal lobe function, including executive function, and activity disturbances (wandering, purposeless activities and inappropriate activities). METHODS: Among 75 consecutive outpatients with AD, 50 subjects with a Clinical Dementia Rating (CDR) score of 1 or 2 were selected and divided into two groups based on data obtained from interviews with their caregivers: an aberrant motor behaviors (AMB) group (n = 22), and a non-aberrant motor behaviors (NAMB) group (n = 28). Aberrant motor behavior was defined according to whether the "activity disturbance" score (ranging from 0 to 9) of the Behavioral Pathology in Alzheimer Disease (Behave-AD) scale was 0 or >or=1. The total and subtest scores of the Frontal Assessment Battery (FAB) were then compared between the two groups. RESULTS: Significant differences were found between the FAB total (P < 0.05) and the subtest scores (lexical fluency, conflicting instructions; P < 0.05) in the two groups. The FAB score was significantly associated with the activity disturbance score (r = -0.49; P<0.001). A stepwise multiple regression analysis showed that only the FAB score significantly influenced the activity disturbance score (P < 0.001). CONCLUSIONS: This finding suggested that in addition to episodic memory disturbance, frontal lobe dysfunctions might lead patients with AD to develop aberrant motor behavior.

Correlation between a reduction in Frontal Assessment Battery scores and delusional thoughts in patients with Alzheimer's disease.

AIMS: The purpose of the present study was to investigate the relationship between delusional thoughts (delusional ideation or misidentification) and frontal lobe function using the Japanese version of the Frontal Assessment Battery (FAB) bedside screening neuropsychological test in early stage Alzheimer's disease (AD) patients. METHODS: Forty-eight probable AD patients with Mini-Mental State Examination score >or=18 points and a clinical dementia rating score of either 0.5 or 1.0 were divided into two groups based on data obtained from interviews with their caregivers: a delusional thought group (n = 19) and a non-delusional thought group (n = 29). The FAB total and subtest scores were then compared for the two groups. RESULTS: Significant differences were found between the FAB total (P < 0.01) and subtest scores (similarities, motor series, conflicting instructions; P < 0.05) for the two groups. Multiple regression analysis showed that delusional thought was significantly associated with the FAB total score. CONCLUSIONS: In addition to episodic memory disorders, a reduction in the FAB score may reflect frontal lobe dysfunctions, including executive function, in patients with AD, leading to delusional ideation.

Effectiveness of carbamazepine for benzodiazepine-resistant impulsive aggression in a patient with frontal infarctions.

Anticonvulsants have been used for the treatment of impulsive aggression since the 1980s. A 50-year-old man suffered from irritability and agitation after developing a right ipsilateral frontal lobe infarction as a result of Moyamoya disease; these symptoms caused difficulties with his working and interpersonal relationships. The patient had been treated using multiple benzodiazepine agents for 2 years but his symptoms had not improved. However, after treatment with carbamazepine (CBZ; 200 mg) was begun, the patient's irritability and agitation gradually decreased. The efficacy of CBZ treatment in this patient suggests a method for controlling benzodiazepine-resistant impulsive aggression.