Nystagmus
Conditions
Keywords
gabapentin, memantine, nystagmus, Drug treatment
Brief summary
Involuntary oscillations of the eyes (nystagmus) impairs vision so that affected patients, who have neurological disorders such as Multiple Sclerosis (MS) , cannot read or watch TV. Two medicines have been reported to suppress nystagmus and improve vision in such patients: gabapentin and memantine. The investigators set out to test which of these two drug was more effective by carrying out a double-blind cross-over study. In this way, we could determine which drug worked best in each patient.
Detailed description
The study entails careful measurements of visual acuity and precise measurements of eye movements, using a contact lens device (magnetic search coil method). In this way, it is possible to make objective and reliable measurements of the effect of each drug, which are unbiased by the investigator or the patient.
Interventions
DRUGgabapentin
increasing to 1200 mg/day
DRUGmemantine
increasing to 40 mg/day
Sponsors
Case Western Reserve University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Adult (18 years or older) males or females with acquired nystagmus that is degrading their vision
Exclusion criteria
* Pregnant women * Individuals who cannot describe their visual symptoms, cooperate with testing, or give informed consent * Individuals with intolerance of gabapentin or memantine
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | After 2 weeks of therapy, for both drugs | — |
| Percent Change in Median Eye Speed | After 2 weeks of therapy, for both drugs | Median eye speed during attempted visual fixation by each eye |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| All Study Participants Increasing dose to 300 mg four times per day (total of 1200 mg/day) for the gabapentin.
Increasing dose over two weeks to 20 mg twice/day (total of 40 mg/day) for memantine. | 10 |
| Total | 10 |
Baseline characteristics
| Characteristic | All Study Participants |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 10 Participants |
| Age, Continuous | 43.5 years STANDARD_DEVIATION 14.9 |
| Region of Enrollment United States | 10 participants |
| Sex: Female, Male Female | 7 Participants |
| Sex: Female, Male Male | 3 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 10 | 0 / 10 |
| serious Total, serious adverse events | 0 / 10 | 0 / 10 |
Outcome results
Primary
Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing
Time frame: After 2 weeks of therapy, for both drugs
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 1, Right Eye | 0 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 1, Left Eye | 0.2 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 2, Right Eye | 0.1 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 2, Left Eye | 0.2 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 3, RIght Eye | -0.1 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 3, Left Eye | NA logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Patricipant 4, RIght Eye | 0.3 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 4, Left Eye | 0.1 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 5, Right Eye | 0.1 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 5, Left Eye | 0 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 6, RIght Eye | 0.4 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 6, Left Eye | 0.2 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 7, Right Eye | -0.1 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 7, Left Eye | 0.1 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 8, Right Eye | 0.1 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 8, Left Eye | 0 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 9, Right Eye | 0 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 9, Left Eye | 0 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 10, Right Eye | -0.1 logMAR |
| Gabapentin | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 10. Left Eye | 0.1 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 9, Left Eye | 0 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 1, Right Eye | 0.1 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 6, RIght Eye | 0 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 1, Left Eye | 0.2 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 8, Left Eye | 0.1 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 2, Right Eye | 0.2 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 6, Left Eye | 0.2 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 2, Left Eye | 0 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 10. Left Eye | 0.2 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 3, RIght Eye | -0.2 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 7, Right Eye | 0.1 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 3, Left Eye | NA logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 9, Right Eye | 0 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Patricipant 4, RIght Eye | -0.1 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 7, Left Eye | 0.1 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 4, Left Eye | 0.1 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 10, Right Eye | 0.3 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 5, Right Eye | 0.2 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Participant 8, Right Eye | 0 logMAR |
| Memantine | Change in logMAR Visual Acuity of Each Eye, Measured During Far or Near Viewing | Particpant 5, Left Eye | 0.1 logMAR |
Primary
Percent Change in Median Eye Speed
Median eye speed during attempted visual fixation by each eye
Time frame: After 2 weeks of therapy, for both drugs
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Gabapentin | Percent Change in Median Eye Speed | Participant 3, RIght Eye | -53.5 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 1, Right Eye | -59.1 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 1, Left Eye | -69.8 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 2, Right Eye | -19.9 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 2, Left Eye | -19.8 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 3, Left Eye | -41.3 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Patricipant 4, RIght Eye | -72.8 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 4, Left Eye | -76.6 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 5, Right Eye | -56.6 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Particpant 5, Left Eye | -42.0 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Particpant 6, RIght Eye | -26.0 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Particpant 6, Left Eye | -25.9 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Particpant 7, Right Eye | 49.5 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Particpant 7, Left Eye | 26.5 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 8, Right Eye | -0.9 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 8, Left Eye | -0.7 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Particpant 9, Right Eye | -39.5 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 9, Left Eye | -44.1 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 10, Right Eye | 159 Percent change |
| Gabapentin | Percent Change in Median Eye Speed | Participant 10. Left Eye | 104.4 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 9, Left Eye | -19.4 Percent change |
| Memantine | Percent Change in Median Eye Speed | Particpant 6, RIght Eye | -44.8 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 1, Right Eye | -21.5 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 8, Left Eye | -24.8 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 1, Left Eye | -35.1 Percent change |
| Memantine | Percent Change in Median Eye Speed | Particpant 6, Left Eye | -29.5 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 2, Right Eye | -26.0 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 10. Left Eye | -79.3 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 2, Left Eye | -35.5 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 3, RIght Eye | -44.6 Percent change |
| Memantine | Percent Change in Median Eye Speed | Particpant 7, Right Eye | -29.0 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 3, Left Eye | -40.2 Percent change |
| Memantine | Percent Change in Median Eye Speed | Particpant 9, Right Eye | 2.2 Percent change |
| Memantine | Percent Change in Median Eye Speed | Patricipant 4, RIght Eye | -8.6 Percent change |
| Memantine | Percent Change in Median Eye Speed | Particpant 7, Left Eye | -24.1 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 4, Left Eye | 11.4 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 10, Right Eye | -80.6 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 5, Right Eye | -35.5 Percent change |
| Memantine | Percent Change in Median Eye Speed | Participant 8, Right Eye | -60.4 Percent change |
| Memantine | Percent Change in Median Eye Speed | Particpant 5, Left Eye | -26.5 Percent change |