Usefulness and reliability of neurological signs for level diagnosis in cervical myelopathy caused by soft disc herniation.

We retrospectively analyzed neurological signs of 106 patients with cervical myelopathy caused by single-level soft disc herniation. Neurological signs that were intensively analyzed were deep tendon reflexes, the uppermost level of impaired pinprick sensation, the uppermost weak muscle, and region of numbness in the hands. Characteristic signs for each intervertebral level were deduced, and sensitivity, specificity, and accuracy of these signs were calculated. Deep tendon reflexes were specific signs for each intervertebral level, although not as sensitive as the neurological signs. Muscle weakness and pinprick sensation were neither sensitive nor specific. Hand numbness was moderately sensitive and specific. On the whole, there was no neurological sign that was both highly sensitive and specific for an intervertebral level, and therefore, neurological level diagnosis in cervical myelopathy should be performed comprehensively according to more specific signs, i.e., deep tendon reflexes and hand numbness.