What is cervical myelopathy, and how does it differ from ALS?

Cervical myelopathy is damage to the spinal cord (myelon) at the level of the cervical spine (cervical myelon). Common causes of cervical myelopathy include bony changes in the cervical spine, narrowing of the spinal canal, and compression of the spinal cord due to degenerative changes in the spine or a massive herniated disc. As a result of the spinal cord damage, paralysis and muscle atrophy in the arms, as well as spasticity in the legs, may develop—symptoms that are also present in a similar way in ALS.

Because of this similarity, cervical myelopathy is one of the differential diagnoses for ALS; therefore, magnetic resonance imaging (MRI) is usually recommended to confirm a diagnosis of ALS. Certain clinical presentations make cervical myelopathy unlikely (even without MRI). For example, the occurrence of a bulbar syndrome (speech and swallowing difficulties) is not caused by cervical myelopathy. Likewise, a widespread distribution of flaccid paralysis (peripheral paresis) and muscle atrophy in the trunk and lower extremities makes the differential diagnosis of cervical myelopathy unlikely.