Relationships Between Balance and Cognition in Patients With Subjective Cognitive Impairment, Mild Cognitive Impairment, and Alzheimer Disease

Gro Gujord Tangen; Knut Engedal; Astrid Bergland; Tron Anders Moger; Anne Marit Mengshoel

doi:10.2522/ptj.20130298

Abstract

Background Balance impairments are common in patients with Alzheimer disease (AD), but which aspects of balance are affected, at which stage of cognitive impairment, and their associations with cognitive domains remain unexplored.

Objectives The aims of this study were: (1) to explore differences in balance abilities among patients with subjective cognitive impairment (SCI) or mild cognitive impairment (MCI), mild AD, and moderate AD and (2) to examine the relationship between the various aspects of balance and cognitive domains.

Design This was a cross-sectional study.

Methods Home-dwelling patients with SCI or MCI (n=33), mild AD (n=99), and moderate AD (n=38) participated in this study. The Balance Evaluation Systems Test (BESTest), comprising 6 subscales—“Biomechanical Constraints,” “Stability Limits/Verticality,” “Anticipatory Postural Adjustments,” “Postural Responses,” “Sensory Orientation,” and “Stability in Gait”—was used to assess balance. Cognitive domains were assessed using the following measures: Mini-Mental Status Examination, Word-List Learning Test from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Verbal Fluency Test, Clock Drawing Test, and Trail Making Test, parts A and B (TMT-A and TMT-B, respectively). Two-way between-group analyses of variance, adjusted for age, were used to analyze differences among the groups. Multiple linear regression analysis was used to explore the associations between balance and cognition.

Results Differences were found between the groups on all BESTest subscales; the moderate AD group had the worst scores. The TMT-B (measuring executive function) was associated with all of the BESTest subscales after controlling for demographic factors.

Limitations The cross-sectional design hampered interpretation of the development of balance impairments.

Conclusions The study findings indicate that all aspects of balance control deteriorate with increasing severity of cognitive impairment and that executive function plays an important role in balance control. Physical therapists should pay attention to these findings both in clinical practice and in future research.

Footnotes

Ms Tangen, Dr Engedal, Dr Bergland, and Dr Mengshoel provided concept/idea/research design. Ms Tangen, Dr Moger, and Dr Mengshoel provided data analysis. Ms Tangen, Dr Engedal and Dr Mengshoel provided project management. Dr Engedal provided institutional liaisons. Ms Tangen and Dr Mengshoel provided fund procurement. Ms Tangen and Dr Engedal provided study participants, data collection, and facilities/equipment. All authors provided writing and consultation (including review of manuscript before submission).
The authors thank all of the participants for their cooperation in this study and the staff at Oslo University Hospital, Charlotta Hamre and Åse S. Slemdal, for participation in the data collection.
The Regional Committee for Medical and Health Research Ethics in the Southeast of Norway approved the study.
A poster presentation of the results of this study, in part, was given at the Joint World Congress of the International Society for Posture & Gait Research, Gait and Mental Function; June 22–26, 2013; Akita, Japan.