Posted on December 19, 2017

A leading researcher at Weill Cornell Medicine-Qatar (WCM-Q) has published a paper highlighting the risk of misdiagnosing diabetic neuropathy, a common diabetes-related complication.

Dr. Rayaz Malik, WCM-Q Professor of Medicine, explained that diabetic neuropathy - nerve damage - presents with very similar symptoms to other diseases of the nervous system, particularly chronic inflammatory demyelinating neuropathy, known as CIDP. Telling the two apart is crucially important because diabetic neuropathy cannot be reversed but CIDP can often be treated extremely effectively, preventing the progression of debilitating symptoms like sensory loss, pain and weakness with impaired movement.

Dr. Malik explained: “When diabetes patients present with neurological disorders it is understandable that doctors attribute this to diabetic neuropathy because it is such a common complication. However, our research showed that a significant minority of patients diagnosed with diabetic neuropathy, actually have CIDP, which is far more treatable and has much better outcomes. “We therefore believe there is a very strong argument for finessing clinical approaches in order to prevent misdiagnosis and ultimately improve outcomes for patients.”

Diabetic neuropathy is a condition in which the peripheral nerves are damaged due to high blood glucose and vascular risk factors like high blood pressure, and lipids as well as being overweight. Treatment is based on controlling blood glucose, blood pressure and lipids with drugs and dietary changes. In contrast, in CIDP the nerve damage occurs because the body’s immune system erroneously attacks the myelin sheath, a fatty structure that covers and protects nerves as well as the axons. Although nerve damage cannot be reversed in either disease, CIDP can be controlled effectively with immunosuppressant drug therapies.

Dr. Malik added: “Because nerve damage cannot currently be reversed in diabetic neuropathy it is very important that patients who have CIDP are correctly diagnosed and treated as early as possible so that we limit long-term nerve damage.” Dr. Malik and his research colleagues reported their findings in a review paper entitled ‘CIDP and other inflammatory neuropathies in diabetes – diagnosis and management’, published in the renowned journal Nature Reviews Neurology. The paper was also contributed to by researchers at Aston University in the UK, and University Hospital Essen and Heinrich-Heine University in Germany.

Dr. Malik has also recently published groundbreaking research into the genetic basis of another type of neuropathy: familial neuropathic chronic itch, which was shown to be associated with COL6A5, a gene, which encodes a protein from which the connective tissue collagen is made. Through genetic analysis of the members of three multigenerational families Dr. Malik and colleagues were able to identify two rare variants of COL6A5 that appear to be involved in causing itch. This allowed the researchers to infer that the chronic itching sensation experienced by the patients was not caused by a dysfunction of the nervous system, but rather by a problem with the collagen surrounding the nerves.

The study also determined that histamines, which are frequently used to treat itch, are ineffectual in such cases, as the itch is not caused by an allergic reaction. Instead, a class of drugs called gabapentinoids that inhibit neurotransmission are more effective. The study, ‘COL6A5 variants in familial neuropathic chronic itch’ was published in Brain: a Journal of Neurology, published by Oxford University Press. Dr. Khaled Machaca, Associate Dean of Research at WCM-Q, said: “The impact that Dr. Malik’s publications are having, both in terms of defining novel disease-causing mutation and in setting international guidelines of diagnosis and treatment of diabetic neuropathy, is exceptional and wide-ranging. This fits within WCM-Q and Qatar Foundation’s mission and vision of seeking cutting-edge findings toward improving the health and healthcare of patients in Qatar.”