LESIONS

A Guide to Localisation in Neurology

Case 13 - numb hands and stiff legs

Outcome

Urgent MRI spine demonstrated a C4/C5 disc prolapse compressing the spinal cord from in front (image A - sagittal view).

Degenerative changes were seen at multiple levels in the cervical spine, as is frequent at this age, and with some levels featuring mild narrowing of exit foramina and contact with nerve roots. These were evident at levels C3/C4 (B), C4/C5 (C) and C5/C6(D) - although none of these were clinically evident. Disc bulges at other levels did not compress the cord.

The patient was admitted to the neurosurgical unit and underwent posterior decompression surgery, with removal of the spinous process and bilateral laminectomy. In the immediate 24 hours post-operatively she felt some improvement in the numbness and walking, though still had minor weakness in her hands. The Hoffman signs disappeared, but bilateral ankle clonus persisted.

3 months after surgery the patient felt improvement though still had some residual spasticity in the legs. It had been explained to her that the operation would not likely reverse the existing damage, but was to prevent progression - and certainly she was no worse.

Compressive cervical myelopathy at C4/C5 due to a central disc prolapse, with improvement after posterior decompression.

1. Compressive cervical myelopathy may be painless, and causes walking problems and difficulty with hand usage. There may be variable degrees of sensory disturbance and bladder and bowel involvement
2. Imaging the cervical spine is vital in anybody with upper motor neuron signs involving all four limbs. Brain lesions are unlikely to cause this pattern but can do, particularly lower brainstem, so brain imaging is also useful
3. Myelopathy can be divided into compressive (including from within) and non-compressive causes to help organise the diagnostic approach
4. Surgical decompression can prevent myelopathy getting worse but will not necessarily reverse existing cord damage, unfortunately