Methylphenidate to Improve Balance and Walking in MS

The primary outcome of this study will be the difference between mean change in TUG time between methylphenidate and placebo treated subjects at 6 weeks. Mean changes will be compared for active and placebo treated subjects using Bayesian analysis.

Mean changes in APR latency at 6 weeks will be compared for active and placebo treated subjects using Bayesian analysis.

Mean changes in Timed 25 Foot Walk (T25FW) at 6 weeks will be compared for active and placebo treated subjects using Bayesian analysis.

Mean changes in the score attained on the Pittsburgh Sleep Quality Assessment Questionnaire at 6 weeks will be compared for active and placebo treated subjects using Bayesian analysis. Scale ranges from 0-21 points, with higher numbers indicating poorer sleep quality.

Mean changes in the score attached on the Modified Fatigue Index Scale at 6 weeks will be compared for active and placebo treated subjects using Bayesian analysis. Scale ranges from 0-84 points, with higher scores indicating greater fatigue.

The most common rotary chair testing is a battery of subtests, each at a specific rate (Hz) of chair rotation from side to side. The participant is secured in the chair in total darkness while the eyes are monitored by infrared cameras. We completed tests from 0.04 to 0.64 Hz to assess the vestibular system across a range of head movements. The chair and participant's head move together while the cameras track the velocity of the eyes; eye velocity reveals how the vestibular system responds to head velocity. VOR gain is the ratio of average chair (i.e. head) velocity to average eye velocity, and is represented on a unitless scale from 0 to 1. VOR gain close to 1 indicates that eye velocity is nearly equal and opposite to head velocity. While there are normative ranges for VOR gain, we are most interested in is change in mean gain (6-week tests minus baseline tests) for the active and placebo groups.

Mean changes in VOR asymmetry, which is a measure of the strength of the eye responses in one direction compared with the other as measured by rotary chair testing at 6 weeks, will be compared for active and placebo treated subjects using t-tests, or other appropriate statistical analyses. A range of frequencies was tested from 0.04 Hz to 0.64 Hz, as is standard for rotary chair testing. The range of frequencies (i.e. chair speeds) assesses the vestibular system across a range of head movements. This helps to identify abnormality, which may manifest at different frequencies of movement. The measurement outcomes for rotary chair testing are gain, phase and asymmetry of the eye movements.

Mean changes in VOR phase, which is a measure of the timing (in degrees) of the eye movements relative to the chair movement, as measured by rotary chair testing at 6 weeks, will be compared for active and placebo treated subjects using t-tests, or other appropriate statistical analyses. A range of frequencies was tested from 0.04 Hz to 0.64 Hz, as is standard for rotary chair testing. The range of frequencies (i.e. chair speeds) assesses the vestibular system across a range of head movements. This helps to identify abnormality, which may manifest at different frequencies of movement. The measurement outcomes for rotary chair testing are gain, phase and asymmetry of the eye movements.