Most patients with unknown spinal cord disease later given specific diagnosis, study shows

"Our review draws attention to the critical need to properly diagnose spinal cord disease to initiate appropriate therapy early on and avoid unnecessary and potentially harmful treatments," says B. Mark Keegan, M.D., Mayo Clinic neurologist and senior author.

Of 226 adult patients referred to Mayo Clinic for spinal cord inflammation of unknown cause between Dec. 1, 2010, to Dec. 31, 2015:

• Diagnosed correctly: 41 patients (18 percent)
• Received a different diagnosis: 158 patients (69.9 percent), including multiple sclerosis, neuromyelitis optica or vascular strokes of the spinal cord
• Required treatment changes: 55 patients (24 percent)
• Had no spinal cord disease diagnosis confirmed: 27 patients (11.9 percent)

Severe spinal cord inflammation can lead to disability. Symptoms vary widely, including paralysis, blindness, numbness or tingling in arms and legs, or bladder and bowel problems.

"Our study increases awareness that patients may benefit from referral to specialized care centers to correctly diagnose a specific cause for spinal cord disease rather than lumping patients into a category prematurely as having spinal cord inflammation of unknown cause," Dr. Keegan says.

From the time patients presented with symptoms until final diagnosis was a median of nine months, the researchers note.

"Identifying the correct, specific diagnosis often can be challenging for physicians who do not see a high volume of patients with spinal cord impairment," says Nicholas Zalewski, M.D., a clinical fellow in the Department of Neurology at Mayo Clinic and first author on the study. "Although we continue to identify helpful clinical and imaging signature features that aid in recognizing the correct underlying cause, these findings often overlap among the different causes of spinal cord disease, and, thus, it's challenging to identify the right diagnosis."

When patients receive an "unknown cause diagnosis," they often aren't referred for further neuroimaging or lab tests that detect antibodies in the blood, the authors note.

"Only some causes of spinal cord impairment have definitive blood tests for them," adds Eoin Flanagan, M.B. B.Ch., a Mayo Clinic neurologist and co-author. "The other causes of spinal cord impairment rely on evaluation by experienced clinicians, proper MRI investigations and MRI reads by experts."

The authors see this study helping improve the diagnosis of specific spinal cord disease.

"Our review shows that specialty centers are able to identify specific causes for presumed inflammatory spinal cord disease that has been listed without a known cause," Dr. Keegan says. "This has been possible because of dedicated research at Mayo Clinic and other centers to evaluate patients with spinal cord disease."

Study limitations include short clinical follow-up and a referral-based population.