Acute focal neurologic deficits were also reported, often occurring as a consequence of stroke or stroke-like episodes secondary to vasculopathy and vasculitis. Longstanding disease was anecdotally linked to normal pressure hydrocephalus, which impairs mental status, gait, and urinary control; symptoms generally improved after treatment with corticosteroids.
RA commonly affects the cervical spine; some studies reported cervical involvement in up to 50% of patients. Progressive spinal involvement is generally a consequence of severe inflammation and destructive changes that can lead to cord compression and subsequent myelopathies. The most common form is atlantoaxial subluxation; subaxial subluxation and cranial settling into the spinal cord can also occur. There is also evidence that RA can impact the lumbar spine, accelerating degenerative changes in the disc space.
Peripheral nervous system involvement is also relatively common. Reports suggest that up to 85% of RA patients have subclinical neuropathy and up to 20% experience symptoms such as pain, sensitivity, and muscle weakness.
Compressive neuropathies are associated with joint changes and synovial swelling that cause nerve entrapment; common manifestations include carpal tunnel syndrome, posterior interosseous nerve palsy, cubital tunnel syndrome, tarsal tunnel syndrome, and Morton’s neuroma. Noncompressive neuropathy is often secondary to treatment medications, vasculitis, and amyloidosis; symptoms include numbness, paresthesias, pain, motor weakness, and loss of sensation.
Disease Activity or Side Effect?
For some neuropsychiatric conditions, the disease process is the most likely culprit and can have direct or indirect effects, according to Perry Nicassio, PhD, a clinical professor of psychiatry from the University of California-Los Angeles Medical Center who has spent decades researching the relationship between mental health and autoimmune disorders.
“Disease activity may affect both brain functioning and impact quality of life and disability. Higher disease activity is also associated with poor sleep,” Dr. Nicassio told Clinical Pain Advisor, referencing a study in which he demonstrated that sleep loss contributes significantly to symptoms of pain and depression in RA.2
More often, the relationship between a neuropsychiatric condition and RA is unclear and possibly multifactorial.
“The effects of chronic disease — as well as peripheral inflammation — can directly act on the neural tissue, or [neuropsychiatric manifestations] can occur secondary to medication,” Dr. Joaquim pointed out, noting the links between various RA treatments and neuropsychiatric complications.