P-16: Mal de Debarquement Syndrome as a Differential Diagnosis for Post Concussion Dizziness
Ms. Jennifer Guan
Michael G. DeGroote School of Medicine
Topic: Neurotrauma and Patient Outcomes
Dizziness is one of the most common complaints after a concussion with an estimated incidence of 43-81% of individuals. There are various proposed peripheral and central vestibular causes for post-concussion dizziness (PCDz), as well as causes including autonomic dysregulation, cervicogenic dizziness, and medication side effects. A subset of patients describes their PCDz as periodic floating, rocking, spinning and tilting, head-motion intolerance, visual vertigo, imbalance, and feelings of unsteadiness that vary in severity day to day that have persisted for three or more months. These patients do not recover with conventional treatments for chronic PCDz. We theorize that these patients with chronic PCDz that have been refractive to conventional treatments may in actuality have developed a condition called Mal de Debarquement Syndrome (MdDS) from concussion. MdDS is a rare neurotological disorder characterized by subjective symptoms of rocking, bobbing, or swaying sensation that persists for over one month. This syndrome has a proposed classification of either motion triggered (MT) MdDS or spontaneous onset (SO) MdDS. Chronic PCDz would be placed in the SO MdDS classification as this subtype does not involve any exposure to passive motion. Chronic PCDz and MdDS have similar described symptoms of rocking and swaying sensation, affect more women than men, reduce a patient’s quality of life, and are associated with motion sensitivity and nausea. Vestibular investigations and conventional MRI are negative in these two groups. SO MdDS and PCS patients are reported to have a previous migraine that may make them more vulnerable to the development of their condition. Both syndromes have proposed underlying central mechanisms and are associated with secondary psychological and behavioral factors. Treating SO MdDS and chronic PCDz with a vestibular migraine protocol has been proposed to include lifestyle changes and pharmacotherapy. Antidepressant and anxiolytic agents has seen modest success. Repetitive transcranial magnetic stimulation (rTMS) is being studied as a treatment option for both conditions and shows promising results. We conclude that concussion can trigger SO MdDS, and that this should be considered in the differential diagnosis of patients with chronic PCDz.