Episodic Hypothermia Primarily Affects Advanced Secondary Progressive MS

Episodic hypothermia is an affliction that predominantly affects people with advanced secondary progressive multiple sclerosis (MS), according to a study recently published in Multiple Sclerosis Journal.

Researchers included 156 subjects from the Mayo Clinic’s electronic medical record between 1996 and July 2015. There were 34 subjects (71% female) with comorbid MS and hypothermia, of whom 32 (94%) showed progressive MS when episodic hypothermia developed. The group had a median expanded disability status scale of 8.0 and a median duration of MS of 19.9 years. The main symptom in affected patients was altered consciousness. Magnetic resonance imaging (MRI) scans found lesions on the hypothalamus in just 4 (14%) individuals. Though the presumed cause of episodic hypothermia in 19 (56%) of these individuals was infection, this was clinically verified in just 9 (28%).

To retrieve records, the study researchers searched for a diagnosis of MS in the electronic medical records and hypothermia in other fields. After confirming accurate diagnoses in participants, they collected the necessary data. This included a search for hypothalamic lesions via MRI scans, which were available for 28 individuals.

Although episodic hypothermia is known to present in some individuals with MS, just 20 cases are on record and little is known about the rate and extent to which it occurs. A hypothalamic lesion is suspected to precipitate episodic hypothermia, but there has been inconclusive evidence for this. The researchers sought to present data on a group of individuals with concurrent MS and episodic hypothermia with this review.

Researchers conclude that episodic hypothermia “occurs predominantly in patients with advanced secondary progressive MS. The major manifestation is altered consciousness. Infection is often suspected as causal, but infrequently confirmed. Although commonly implicated, hypothalamic lesions were rarely evident on MRI and were absent in two post-mortem evaluations.”

Reference

Toledano M, Weinshenker BG, Kaufmann TJ, Parisi JE, Paz Soldán MM. Demographics and clinical characteristics of episodic hypothermia in multiple sclerosis [published online March 23, 2018]. Mult Scler. doi: 10.1177/1352458518767045