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This short review summarizes developments and achievements made during the last few years in spinal neurology and includes all relevant papers published in the Journal of Neurology during this time. A focus of the review concerns the debate about the significance of translational medicine in spinal cord injury with the introduction of new drugs directed to achieve some spinal cord repairs.

Patients with Parkinson's disease (PD) have difficulties in performing complex bimanual movements. Here we have examined acquisition and performance of a bilateral obstacle stepping task to see whether these difficulties are also present during bipedal movements. Subjects had to minimize foot clearance when repeatedly stepping on a treadmill over randomly approaching obstacles on either side. The subjects had full vision and received acoustic feedback information about task performance. Foot clearance improved in healthy and PD subjects during the acquisition of the task. However, PD subjects showed a slower improvement and achieved a poorer performance level. Thus, in contrast to unilateral obstacle stepping, where no deficits in performance after task repetition were found in PD subjects, bilateral obstacle stepping was poorer in these subjects compared to healthy subjects. The present results extend findings from upper to lower limb movements, namely that PD subjects have difficulties in the performance of bilateral motor tasks.

During recent years, evidence has come up that bipedal locomotion is based on a quadrupedal limb coordination. A task-dependent neuronal coupling of upper and lower limbs allows one to involve the arms during gait but to uncouple this connection during voluntarily guided arm/hand movements. Hence, despite the evolution of a strong cortico-spinal control of hand/arm movements in humans, a quadrupedal limb coordination persists during locomotion. This has consequences for the limb coordination in movement disorders such as in Parkinson’s disease (PD) and after stroke. In patients suffering PD, the quadrupedal coordination of gait is basically preserved. The activation of upper limb muscles during locomotion is strong, similar as in age-matched healthy subjects although arm swing is reduced. This suggests a contribution of biomechanical constraints to immobility. In post-stroke subjects a close interactions between unaffected and affected sides with an impaired processing of afferent input takes place. An afferent volley applied to a leg nerve of the unaffected leg leads to a normal reflex activation of proximal arm muscles of both sides. In contrast, when the nerve of the affected leg was stimulated, neither on the affected nor in the unaffected arm muscles EMG responses appear. Muscle activation on the affected arm becomes normalized by influences of the unaffected side during locomotion. These observations have consequences for the rehabilitation of patients suffering movement disorders.

Objectives: To improve the diagnosis of damaged spinal motor pathways in incomplete spinal cord injury (iSCI) by assessing the facilitation of lower limbs motor evoked potentials (MEP). Methods: Control subjects (n = 12) and iSCI patients (n = 21) performed static and dynamic isometric foot dorsiflexions. MEPs induced by transcranial magnetic stimulation and EMG background of tibialis anterior muscle (TA) were analyzed. Static and dynamic muscle activation was performed at comparable levels of maximal voluntary contraction (MVC). The influence of the motor tasks on the excitability and facilitation of MEPs was compared between controls and iSCI patients. Results: In the controls an increased facilitation of TA MEP at lower levels of dynamic compared with static activation (10-20% MVC) could be shown. At matched EMG background level the MEP responses were significantly increased. In the iSCI patients at a comparable level of TA activation the MEP responses were significantly reduced and 3 different patterns of MEP responses could be distinguished: i) preserved increment of TA MEP in the dynamic motor task, ii) unchanged MEP size in the dynamic and static motor task, and iii) elicitable MEPs in the dynamic motor task,which were abolished in the static motor task. Conclusions: Static and dynamic motor tasks have different effects on TA MEP facilitation. The task-dependent modulation of TA MEPs is comparable to that described for upper limb muscles. Complementary to the MEP delay this approach allows for an estimation of the severity of spinal tract damage. The task-dependent modulation of TA MEPs is an additional diagnostic tool to improve the assessment and monitoring of motor function in iSCI