No impact of anti-inflammatory medication on inflammation-driven recovery following cervical spinal cord injury in rats

Following spinal cord injury (SCI), inflammation is associated with the exacerbation of damage to spinal tissue. Consequently, managing inflammation during the acute and subacute phases is a common target in SCI treatment. However, inflammation may also induce potential benefits, including the stimulation of neuroplasticity and repair. This positive role of inflammation in spinal cord healing and functional recovery is not fully understood. To address this knowledge gap, we examined the effects of two common anti-inflammatory medications, Diphenhydramine and Methylprednisolone, on the efficacy of rehabilitative motor training on recovery from subacute cervical SCI in adult rats. Training depends critically on neuroplasticity thus if inflammation is a key regulator, we propose that anti-inflammatory drugs will reduce subsequent recovery. Both drugs were administered orally over one month, alongside task-specific reaching and grasping training. After treatment, no substantial changes in motor recovery or lesion size between the treated and control groups were observed. Treated animals also did not show any discernible changes in sensory function or anxiety-like behavior. Taken together, our data indicate that the prolonged use of these anti-inflammatory agents at commonly used doses did not profoundly impact recovery following an SCI. Therefore, considering earlier reports of the benefits of pro-inflammatory stimuli on plasticity, further studies in this area are imperative to elucidate the true impact of treating inflammation and its implications for recovery after spinal cord injuries.