The spinal cord contains the circuitry to control posture and locomotion after complete paralysis, and this circuitry can be enabled with epidural stimulation [electrical enabling motor control (eEmc)] and/or administration of pharmacological agents [pharmacological enabling motor control (fEmc)] when combined with motor training. We hypothesized that the characteristics of the spinally evoked potentials after chronic administration of both strychnine and quipazine under the influence of eEmc during standing and stepping can be used as biomarkers to predict successful motor performance. To test this hypothesis we trained rats to step bipedally for 7 wk after paralysis and characterized the motor potentials evoked in the soleus and tibialis anterior (TA) muscles with the rats in a non-weight-bearing position, standing and stepping. The middle responses (MRs) to spinally evoked stimuli were suppressed with either or both drugs when the rat was suspended, whereas the addition of either or both drugs resulted in an overall activation of the extensor muscles during stepping and/or standing and reduced the drag duration and cocontraction between the TA and soleus muscles during stepping. The administration of quipazine and strychnine in concert with eEmc and step training after injury resulted in larger-amplitude evoked potentials [MRs and late responses (LRs)] in flexors and extensors, with the LRs consisting of a more normal bursting pattern, i.e., randomly generated action potentials within the bursts. This pattern was linked to more successful standing and stepping. Thus it appears that selected features of the patterns of potentials evoked in specific muscles with stimulation can serve as effective biomarkers and predictors of motor performance.

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The vitamin A derivative, retinal, plays a pivotal role in scotopic and color vision. Although vitamin A deficiency (VAD) presents as a common cause of preventable blindness in areas with poor access to foods rich in vitamin A, it is uncommon in developed countries.We present a 56-year-old male with a history of Crohn's disease and pancreatitis who was referred to our ophthalmology office by optometry for severe dry eyes. He complained of a two-year history of constant blurred vision and nyctalopia. He stated that "images just appear dark." Examination demonstrated mildly decreased visual acuity with severe ocular surface disease and characteristic Bitot's spots in both eyes. Based on the patient's history and physical, a diagnosis of xerophthalmia in the setting of VAD was made. The patient was referred to his internist, he then underwent further evaluation and treatment with vitamin A intramuscular injections post-diagnosis. This case illustrates the potential for VAD secondary to malabsorption from Crohn's disease and the importance of taking a full patient history so systemic causes of ophthalmic symptoms may be promptly identified and treated. VAD is extremely rare in the United States, however, patients at risk for VAD may benefit from regular vitamin A level checks and ophthalmologic evaluation.