CHRONIC ANTI-EPILEPTIC DRUG TREATMENT IS ASSOCIATED WITH CLINICALLY-SIGNIFICANT IMPAIRMENT IN BALANCE FUNCTION [ndash] A TWIN AND MATCHED SIBLING PAIR PILOT STUDY
Abstract number :
2.273
Submission category :
Year :
2005
Submission ID :
5579
Source :
www.aesnet.org
Presentation date :
12/3/2005 12:00:00 AM
Published date :
Dec 2, 2005, 06:00 AM
Authors :
1Sandra J. Petty, 1Lynda M. Paton, 1Terence J. O[apos]Brien, 1,2Natalie El Haber, 3Ben Metcalf, 3Kim Bennell, 4Samuel F. Berkovic, and 1John D. Wark
Anti-epileptic medication users have an increased incidence of bony fractures. Potential causes for this association include bone disease and increased falls both during seizure and at other times.
Aim: To assess the effect of chronic AED use on muscle strength and balance function utilizing a twin and matched sibling AED-discordant pair approach. 7 pairs (6 female, 1 male) 3 monozygous, 1 dizygous and 3 sibling pairs (within 3 years of age) with mean (SD) age 55.6 (17.6) years, height 161 (6) cm, weight 67.9 (13.6)kg were assessed. All pairs were discordant for AED-use with mean duration (SD) of therapy in AED-user 29 (19) years. Previously validated tests of muscle strength, static and dynamic balance and gait that are predictive of falls risk were performed: (i) Nicholas Manual Muscle Tester (NMMT), (ii) Kincom, (iii) Chattecx Balance System (CBS): Sway index (SI), anterior-posterior (AP) and lateral (LR) sway measured in 3 platform positions and (iv) Lord[apos]s balance test (LBT). Human Activity Profile (HAP) was utilized to measure physical activity. Paired t-tests utilized to assess mean within-pair differences (AED user vs. non-user). Relevant serum AED levels were measured and were not above therapeutic range at time of study visit. There was no significant within-pair difference in age, height, weight, muscle strength (NMMT, Kincom) or activity level (HAP). A significant within-pair difference (AED-user vs. non-user) was seen with multiple measures of balance: LBT: eyes closed (+87mm, p=0.026); foam mat eyes open (+46mm, p=0.043); foam mat eyes closed (+193mm, p=0.067 n=5 pairs); CBS: Stable position+ distraction (SI+0.36cm, p=0.013, LR+1.28cm, p=0.00, AP+1.68cm, p=0.02); Anterior-posterior moving platform (SI+0.66cm, p=0.045, AP+2.66cm, p=0.022); Medial-lateral moving platform + distraction (AP +1.16cm, p=0.024). There is significant within-pair difference in balance function in chronic AED users compared to their matched sibling/twin control. This impairment of balance function may have important implications for AED users indicating increased falls risk and therefore risk of fracture. (Dr. Sandra Petty is supported by NHMRC Medical Postgraduate Scholarship.
Epilepsy Association
The Royal Melbourne Hospital Victor Hurley Grants-in-Aid.)