HYPERACTIVE PECTORALIS REFLEX AS AN INDICATOR OF UPPER CERVICAL SPINAL-CORD COMPRESSION - REPORT OF 15 CASES

Myelopathy from cervical spondylosis is often accompanied by hyperrefl exia of the upper-extremity deep tendon reflexes (DTRs). Reflexes such as the pectoralis jerk and the deltoid jerk may only be apparent in t he context of hyperreflexia. Although the nerve roots involved in the reflex arcs are well described, levels of cervical spinal cord compres sion that lead to the hyperreflexia are not as clear. This is of parti cular significance for patients with multilevel cervical spondylosis i n determining the levels responsible for their symptoms. The authors e xamined 15 consecutive patients who presented for treatment of cervica l myelopathy. The clinical examination was then correlated with levels of cervical spinal cord compression by cervical magnetic resonance im aging or computerized tomography with intrathecal contrast enhancement . The presence of a prominent pectoralis jerk was seen only in patient s with spinal cord compression at the C2-3 and/or C3-4 levels (nine pa tients). No patient with compression at or below the C4-5 disc space w ithout coexisting compression at a higher level had hyperactive pector alis reflexes. This association between the C3-4 level and a hyperacti ve pectoralis reflex was significant (p < 0.004, Fisher's exact test). The deltoid reflex was tested in the last nine consecutive patients. It was present in patients with compression of the upper spinal cord a t levels C3-4 and C4-5 (four of five patients) but appeared in only on e of four patients with compression below C4-5. This association did n ot attain statistical significance. The presence of a hyperactive pect oralis reflex is specific for lesions of the upper cervical spinal cor d. Examination of upper-extremity DTRs may be helpful in planning the appropriate levels for surgical decompression in patients with multile vel spondylosis and myelopathy.