International Psychogeriatrics

Research Article

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

Tomoyuki Nagataa1 c1, Shunichiro Shinagawaa2, Yusuke Ochiaia1, Hirohide Kadaa1, Hiroo Kasaharaa1, Kazutaka Nukariyaa1 and Kazuhiko Nakayamaa2

a1 Department of Psychiatry, Jikei University School of Medicine, Kashiwa Hospital, Chiba, Japan

a2 Department of Psychiatry, Jikei University School of Medicine, Tokyo, Japan

ABSTRACT

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 ≥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.

(Received June 09 2009)

(Revised July 30 2009)

(Revised September 21 2009)

(Accepted September 30 2009)

(Online publication December 15 2009)