Text Size: a  |   a 

Problems with Sense of Smell Are Worse in Primary Progressive MS

July 11, 2017

A study finds that problems with sense of smell are more frequent and severe in patients with primary progressive multiple sclerosis (PPMS) than in those with relapsing-remitting multiple sclerosis (RRMS). The research, “Olfactory dysfunction in patients with primary progressive MS,” was published in the journal Neurology: Neuroimmunology and Neuroinflammation. RRMS is attacks of new or increasing neurologic symptoms, such as movement disorders, and then recovery periods. PPMS, on the other hand, gradually increases neurologic disability without recovery periods. Some scientists believe PPMS is a less inflammatory course of MS. However, the differences in the processes that underlie each form are not well understood.

Several researchers think that studying differences in the two groups’ ability to smell, or olfactory dysfunction, could shed light on these underlying processes. Researchers decided to test a hypothesis that olfactory impairment is more pronounced in patients with PPMS than RRMS. The study included 32 patients with PPMS, 32 patients with RRMS, and 32 healthy controls. Researchers used the olfactory Threshold Discrimination Identification (TDI) Test to evaluate sense of smell. It involved patients smelling 46 sniffin’ sticks. Results showed that olfactory dysfunction in 27, or 84%, of the PPMS patients; 10, or 31%, of the RRMS patients, and 1, or 3%, of the healthy controls. The TDI score and all subscores were significantly worse in patients with PPMS than in the controls. It should be noted that researchers acknowledged limitations to the study.

“The findings suggest that olfactory dysfunction might be a surrogate of neurodegeneration in these patients,” the researchers wrote. “Studies correlating olfactory function with radiologic and clinical markers of disease progression would be of interest.”

Via MS News Today