From the Research
The most specific signs of cervical myelopathy, from highest to lowest specificity, are Babinski sign, Tromner sign, clonus, hyperreflexia, and gait abnormalities. According to the most recent and highest quality study 1, the Babinski sign, characterized by upward movement of the great toe when the sole of the foot is stimulated, is considered one of the most specific indicators of upper motor neuron dysfunction in the cervical spine, with a specificity of 93-100%. The Tromner sign, which involves flicking the middle fingernail and observing involuntary flexion of the thumb and index finger, follows closely in specificity, with a specificity of 79-100%. Clonus, a rhythmic muscle contraction typically tested at the ankle, is the third most specific sign, with a specificity of 96-99%. Hyperreflexia, particularly when asymmetric or affecting the lower extremities, ranks fourth, with a specificity that can vary. Gait abnormalities, such as a broad-based, unsteady gait or the characteristic "myelopathic gait," while common, are less specific as they can occur in various neurological conditions.
Key Signs and Symptoms
- Babinski sign: upward movement of the great toe when the sole of the foot is stimulated
- Tromner sign: involuntary flexion of the thumb and index finger when the middle fingernail is flicked
- Clonus: rhythmic muscle contraction typically tested at the ankle
- Hyperreflexia: particularly when asymmetric or affecting the lower extremities
- Gait abnormalities: broad-based, unsteady gait or the characteristic "myelopathic gait"
These signs reflect compression of the spinal cord in the cervical region, disrupting normal descending motor pathways and causing upper motor neuron findings. Early recognition of these signs is crucial as cervical myelopathy is progressive and can lead to permanent neurological damage if left untreated, as highlighted in 2, 3, and 4. The assessment of cervical myelopathy can be challenging, especially early in the course of the disease, and disease-specific functional assessments can aid in the diagnosis, as noted in 5.