Patients suffer when these rare neurological conditions are misdiagnosed

In the field of neurology, treating patients with rare disorders is just part of the job—but this doesn't make diagnosis any easier.

“Any physician, especially neurologists, are aware that rare disorders, taken as a group, are really not that uncommon in clinical practice. As specialists and subspecialists, neurologists often see the cases that are filtered through layers and layers of prior referrals or incorrect diagnoses, and so we are especially biased to search out the rare disorders," Xenos Mason, MD, a neurologist at Keck Medicine of USC, tells MDLinx.

“I am a movement disorder specialist, and so in my own practice the trickiest diagnoses have been people with symptoms that look like common disorders, like Parkinson’s disease or Lewy body dementia, which have turned out to be adult onset of genetic conditions usually presenting in childhood: POLG mutation and Niemann-Pick [type] C, in these cases. Frequently reassessing the patient’s progression and avoiding anchoring have been important [in] making these kinds of diagnoses.”

Years of searching

In some cases, patients who are eventually diagnosed with a rare neurological disorder can spend years searching for answers.

"These often present with a mixture of gait problems, abnormal involuntary movements, and cognitive or psychiatric symptoms (in some cases). It’s not uncommon for patients to have had months or years of evaluation before getting a proper diagnosis," she says.

Trust your gut

Dr. Zahed notes that while autoimmune/paraneoplastic conditions are rare, failing to accurately diagnose such conditions can have significant consequences, such as missing an underlying cancer or the chance to treat a potentially reversible condition.

All the experts who spoke with MDLinx note that, for some rare genetic disorders, there can sometimes be the impression that receiving a genetic diagnosis is not important, as there are so few disease-modifying treatments that will change how a patient manages their disease. But Dr. Zahed argues that a clear diagnosis can provide closure for patients, avoid unnecessary or invasive testing, and help patients find support and advocate for themselves.

Rare doesn't mean hard to treat

“It’s critical to remember that many genetic metabolic disorders are treatable. Ataxia with vitamin E deficiency is one example where early treatment can completely halt the progression of disease. Another is Wilson’s disease. Mitochondrial disorders and Krebs cycle disorders can also be treatable. And cerebrotendinous xanthomatosis is yet another [disease] that can be completely halted with the right treatment,” Dr. Mason says.

“These, and many other [diseases], are more easily diagnosed in kids but sometimes missed in adults. I think the takeaway is that when there is mystery—when things are not completely explained or pieces are missing in your diagnosis or the patient’s progression—bring in more opinions,” she says.