Because of the COVID19 pandemic you are practicing telemedicine. Your patient is a 75-year-old man previously in good health who presents with progressive weakness in his hands and arms coupled with stiffness in his legs. You are told that his neurologic exam was positive for lower motor neuron findings in his upper extremities (weakness, hyporeflexia, some atrophy) and upper motor neuron findings (spaticity, hyperreflexia) in his lower extremities. You are provided an MRI of his spinal cord and a video showing a bedside test.
What is your diagnosis, what test(s) would you order to confirm your suspicions, and what treatment, if any, do you recommend? What is the name and significant of the test shown in the video?
DIAGNOSIS: Cervical myelopathy secondary to compression of the spinal cord by C2-C5 vetebrae.
The video demonstrates a positive Hoffman test (note the involuntary flexion of the thumb and index finger when the examiner flicks the fingernail of the middle finger downward). The Hoffman test is particularly useful in patients with suspected cervical myelopathy, although a positive (or negative) test should not preclude the performance of a MRI, as was done in the presented case.
A thorough neurological examination should be performed on all patients with suspected cervical myelopathy. Patients are deemed to have to have an examination consistent with the level of cord signal change (CSC) if they have normal reflexes proximal (cranial) to the level of CSC, are hyporeflexic at the affected level, and are hyper-reflexic distal (caudal) to the level of CSC. Note, however, that In one study involving 43 patients with cervical myelopathy, CSC correlated poorly with findings on the neurologic examination. In this study, 16% of patients had clonus, 44% had a positive Romberg sign, 60% had an abnormal gait, and 67% had a positive Hoffman sign [1].
It should be noted that the neurologic findings in amyotrophic lateral sclerosis (ALS) (i.e., both upper and lower motor neuron findings) may closely resemble those seen in patients with cervical myelopathies.
Prompt surgical decompression of the spinal cord was done in the presented case.
[1] Nemani, V.M.; Kim, H.J.; Pyaskulkaew, C.; Nguyen, J.T.; Riew, K.D. Correlation of cord signal change with physical examination findings in patients with cervical myelopathy. Spine, 2015, 40(1), 6-10.