Adverse cognitive effect of gabapentin in individuals with spinal cord injury: preliminary findings.

STUDY DESIGN

Prospective observational cohort study.

OBJECTIVES

To assess the effects of gabapentin on neuropsychological variables including memory, attention, and executive function in individuals with spinal cord injury.

SETTING

Santa Clara Valley Medical Center inpatient spinal cord injury unit.

METHODS

Ten patients (three females, seven males) with traumatic spinal cord injury underwent testing, with a mean age of 35.6 years (range 19-59, SD ±15.74). There were five patients with tetraplegia and five with paraplegia. Nine tests to assess neuropsychological function and two tests to assess pain were performed at 1 week post initiation of therapy, and at 4 weeks post initiation of therapy. The neuropsychological tests assessed aspects of memory, attention, and executive function.

RESULTS

The average score for six out of the nine neuropsychological items administered at 1 week post initiation of gabapentin displayed a decrease in cognitive function when compared to baseline. The average score for five out of nine neuropsychological items improved from 1 week post initiation of treatment to 4 weeks post initiation of treatment.

CONCLUSIONS

Gabapentin therapy is associated with a tangible decline in memory, executive function, and attention in individuals with spinal cord injury. However, owing to small sample size, loss of patient follow-up at the 4 week post-treatment assessment, and lack of a control group, we cannot definitively state that any decreases in cognition are solely attributable to treatment with gabapentin.