An etiological classification of myelopathies yields an extensive list of diverse conditions (Table 48.1). In clinical practice, myelopathies are classified into spinal cord syndromes, based on patterns of neurological symptoms and signs, which identify the anatomical location and distribution of spinal cord pathology. The time course of symptoms is useful in distinguishing between different etiologies. Vascular lesions generally present with acute onset or rapid progression of symptoms. Inflammatory disease evolves in a subacute manner and may fluctuate over days or weeks. Compressive lesions also may present with a subacute onset and generally have a progressive course. Degenerative myelopathies are usually slowly progressive over months or years. The evolution and type of spinal cord syndrome suggest certain diagnostic possibilities and guide appropriate investigation.

Symptoms and signs of spinal cord disease

Motor symptoms and signs

The clinical presentation of an evolving myelopathy often is precipitated by limb weakness and spasticity due to corticospinal tract involvement. Arm and leg weakness suggests a cervical cord lesion. A paraparesis, with leg weakness or walking difficulty alone, suggests a lesion of the thoracic spinal cord or below. Progressive cervical cord lesions may evolve in a sequence, beginning with weakness of the arm ipsilateral to the lesion, followed by weakness of the ipsilateral then contralateral leg, and finally the contralateral arm.

Exacerbation of symptoms by exercise, or during increases in body temperature (hot weather or a hot bath) suggests demyelination, but may also occur in dural arteriovenous malformations of the spinal cord.

Motor signs of spinal cord disease reflect involvement of the long tracts of the spinal cord with increased muscle tone, brisk tendon reflexes, extensor plantar responses and weakness of hip and knee flexion and ankle dorsiflexion. Involvement of the anterior horn cells or anterior (motor) spinal nerve roots produces additional lower motor neuron signs of segmental wasting and weakness (Table 48.2).

Sensory symptoms and signs

Back pain

Back pain is often an early complaint of a myelopathy, preceding any motor symptoms. The site of pain may localize the level of a focal structural lesion such as a spinal epidural abscess, vertebral body collapse or intervertebral disc prolapse. Dull, poorly localized backache is common in intrinsic spinal lesions but is of little localizing or diagnostic value.