Motor deficits and recovery during the first year following mild closed head injury

This study examined motor impairments over 1 year following mild closed head injury (CHI). It is the first study to serially assess long-term oculomotor and upper-limb visuomotor function following mild head trauma.

Thirty-seven patients with mild CHI and 37 matched controls were compared at 1 week, 3 months and 6 months and 31 available pairs at 12 months post-injury on measures of saccades, oculomotor smooth pursuit, upper-limb visuomotor function and neuropsychological performance. Symptomatic recovery was sampled using the Rivermead Postconcussion Symptoms Questionnaire.

At 1 week, the group with CHI reported high levels of post-concussional symptoms and exhibited prolonged saccade latencies, increased directional errors, decreased saccade accuracy and impaired fast sinusoidal smooth pursuit concomitant with increased arm movement reaction time, decreased arm movement speed and decreased motor accuracy on upper-limb visuomotor tracking tasks. Neuropsychological testing identified deficits only in verbal learning and speed of processing while attention, short-term/working memory and general cognitive performance were preserved. At 3 and 6 months, the group with CHI continued to show deficits on several oculomotor and upper-limb visuomotor measures in combination with some deficits on verbal learning and improved, yet abnormal, levels of post-concussional symptoms. At 12 months, the group with CHI had no cognitive impairment but residual deficits in eye and arm motor function and continued to show elevated levels of post-concussional symptoms.

The findings indicate that multiple motor systems are measurably impaired up to 12 months following mild CHI and that instrumented motor assessment may provide sensitive and objective markers of cerebral dysfunction during recovery from mild head trauma independent of neuropsychological assessment and patient self-report.