Hypoglossal nerve palsy from cervical spine involvement in rheumatoid arthritis: 3 case reports.

Rheumatoid arthritis (RA) involvement of the cervical spine is a well-known but perhaps underappreciated phenomenon. Neurologic complications of this involvement include pain, myelopathy, and cranial nerve (CN) palsies. However, hypoglossal nerve palsy (CN XII) is rarely diagnosed. Mechanical nerve injury, either from vertical odontoid subluxation or pannus formation, is the suspected mechanism. We present 2 cases of hypoglossal nerve palsy attributed to cervical spine involvement of RA and 1 case of postoperative tongue weakness after cervical fusion in a patient with long-standing RA. These cases show a potentially devastating complication of RA that may be underdiagnosed. Therapy involving the cervical spine must be prescribed with caution in this patient population.