Dynamic changes in the reflex exam of patients with sub-axial cervical stenosis.

Though dynamic changes in the physical exam of patients being evaluated for cervical spine pathology have been reported, there is limited information on the prevalence and clinical features associated with reflex changes in a population undergoing surgical evaluation for cervical spine pathology. Fifty-one patients with at least grade 1 cervical stenosis on MRI underwent initial surgical evaluation for cervical spine pathology. All patients received complete neurologic examinations including dynamic reflex testing in three positions (neck neutral, extended, and flexed) by 2 spine surgeons. The average age was 58.7 years (range, 34-80), with 28 (55%) patients being male. Stenosis at the symptomatic levels was grade 1 in 18 patients (35%), grade 2 in 11 (21%), and grade 3 in 22 (43%). Twenty-one patients (41%) had a dynamic change in reflex exam. The most common change in reflex exam was seen in the Hoffman's reflex with 14 patients (28%). Patients with grade 3 stenosis were more likely to have a static Hoffman's reflex (64%) compared with grade 1 (17%) and grade 2 (18%) (p < 0.05). Patients with grade 3 stenosis had a higher rate of either a static or dynamic Hoffman's reflex (82%) compared with grade 1 (44%) (p < 0.05), but there was no difference between grade 3 and grade 2 (64%) (Table 2). Dynamic changes in reflex exam are commonly seen in patients being evaluated for symptomatic cervical stenosis. The routine neurologic exam can be supplemented with dynamic reflex testing, especially in cases where clinical history or imaging is concerning for cervical myelopathy.