Position Sense, Balance, and Dual Task Performance at the Menstrual Cycle in Females With Multiple Sclerosis

The purpose of this study was to determine the effect of hormonal changes on knee position sense, balance and dual task performance throughout the menstrual cycle in females with MS.

14 females with MS and 13 healthy females with matching ages and genders were included the study. A neurologic examination was performed using the EDSS by a neurologist.

Position sense was measured with Acumar dual digital inclinometer (Acu360, Acumar, Lafayette, USA). Balance was measured with Biodex Balance System (Biodex Medical Systems, Shirley, NY, USA). Dual task performance was evaluated with Time Up and Go test.

• Position Sense (Other): Knee position sense was evaluated with a Acumar dual digital inclinometer. Each participant was asked to wear shorts and to lie down in supine position treatment table. The lower extremity of the participant was positioned in neutral for the knee flexion movement. The placement of the digital inclinometer's attachment was the lateral ridge of the femur and tibia. We actively assisted the participant's knee to the target angle and asked the participant to hold it there for 5 seconds before returning the knee to the starting position. After returning to the starting position, participants attempted to repeat the previously attained angle. Participants indicated verbally when they felt they had reached the angle and held their position. This procedure was repeated 3 times for each limb (non-dominant and dominant). We measured the absolute difference between the target angle and the observed angle and calculated the absolute error score by averaging the 3 trials.
• Balance (Other): To measure postural stability and Limits of Stability this study used a balance device, the Biodex Balance System. Postural Stability: The participants were focused on a characteristic dot (COP, centre of pressure) on the monitor screen. The participant's task was to balance the body in such a way that the dot was in the centre of a circle displayed on the monitor at the point of intersection of the coordinate axes. Test consisted of three 20-second trials, each separated by 10-second breaks. Measurements were repeated three times while their eyes were open/close and analyzed by calculating the average value of measurements. Limits of Stability: The participants are asked to complete the directional tasks displayed on a screen as quickly as possible, with the directions displayed at random. A total of 3 tests were performed, at intervals of 10 s.
• Dual Task Performance (Other): The timed up and go test (TUG) was used in the evaluation of dual task performance. For this test, participants were seated on a standard armless chair and a cone was placed 3 meters away from the chair. Participants were instructed to stand up and (1) walk towards the cone, (2) turn around the cone, (3) walk back to the chair, and (4) sit back on the chair. It was stated that patients should walk without running but as fast as possible. TUG test was performed initially without task, and then with cognitive and motor tasks, respectively. Cognitive task given during the test is counting three backwards from 100 or counting the names starting with the letter "A", and motor task given is to carry three glasses of water on a tray. The time elapses between standing up from the chair and sitting back to chair was recorded as the test result. As time increases, dual task performance decreases.

Primary outcomes

• Knee position sense [through study completion, an average of 1 year]: Knee position sense was evaluated with a Acumar dual digital inclinometer.The absolute error scores (in degrees) for knee flexion at 60° was calculated. As absolute error score increases, position sense decreases.
• Balance [through study completion, an average of 1 year]: To measure postural stability and Limits of Stability this study used a balance device, the Biodex Balance System. Postural Stability: Test consisted of three 20-second trials, each separated by 10-second breaks. Measurements were repeated three times while their eyes were open/close and analyzed by calculating the average value of measurements \[30\]. As a result, overall stability indexes were taken into account for measurement purposes. For these indexes, a low value indicated high postural stability. Limits of Stability: The participants are asked to complete the directional tasks displayed on a screen as quickly as possible, with the directions displayed at random. A total of 3 tests were performed, at intervals of 10 second. The test results were used to determine a total score. The higher the total score, the better the ability of the subjects to transfer the centre of gravity.
• Dual Task Performance [through study completion, an average of 1 year]: The timed up and go test was used in the evaluation of dual task performance. Timed up and go test was performed initially without task, and then with cognitive and motor tasks, respectively. Cognitive task given during the test is counting three backwards from 100 or counting the names starting with the letter "A", and motor task given is to carry three glasses of water on a tray. The time elapses between standing up from the chair and sitting back to chair was recorded as the test result. As time increases, dual task performance decreases.

Sex: Female, ages: 26 Years to 49 Years, accepts healthy volunteers

Inclusion Criteria:

* Inclusion criteria of the MS group were as follows: patients with a confirmed diagnosis of clinically definite MS, physician-administered Expanded Disability Status Scale (EDSS) range of 1-3.5, and having regular menstrual cycle (between 21-35 days).
* Inclusion criteria of the control group were having regular menstrual cycle, and not having neurological problem, any lower extremity orthopedic problems and no use of any contraceptive agents

Exclusion Criteria:

* The exclusion criteria were: patients with acute attacks (three months prior to the study), a Mini-Mental State Examination (MMSE) score of less than 25 points, take oral contraceptive agents, and a history of orthopedic lower extremity problems or other neurological disorders.