Neurographic assessment of intramedullary motoneurone lesions in cervical spinal cord injury: consequences for hand function.

Examination of hand function and neurography of the median- and ulnar nerves was performed in 15 patients with acute and 26 patients with chronic tetraplegia due to cervical spinal cord injury (SCI). 30% of patients showed a mild and 20% a severe axonal lesion of motor fibres of both nerves. The latter is caused by intramedullary damage of ventral horn cells and anterior nerve roots as neurographic examination of sensory nerve fibres was normal in these patients. The most frequent and severe nerve lesion was present in those with lower cervical spinal cord injuries (C6/7-Th1) where the median and ulnar nerves originate. In the latter patients the development of active hand function, which enables the patient to perform active grasping movements, was closely related to the result of neurography, already early after trauma. The results of median and ulnar neurography in tetraplegia due to cervical SCI allow to differentiate between intramedullary damage of motoneurones and the anterior nerve roots (peripheral nervous system) or the pyramidal tract fibres (central nervous system) within the spinal cord responsible for the paresis of the intrinsic hand muscles. Neurography is of prognostic value in cervical SCI to predict the outcome of hand function and therefore influences the appropriate occupational therapy and the program and aims of rehabilitation.