Title: Unraveling the Mystery of "Havana Syndrome
Speaker: Laith AlHadeed, MSc Candidate, Department of Medical Neuroscience, Dalhousie University
Date: Tuesday, June 17, 2025
Time: 11:30am - 12:30pm
Location: Theatre C, Tupper Building
Description: In late 2016, Canadian and U.S. government personnel stationed in Havana, Cuba, began experiencing sudden-onset neurological symptoms, later termed “Havana Syndrome.” These included persistent cognitive, vestibular, and sensorimotor disturbances that were difficult to diagnose.
To investigate these health incidents, we conducted a mixed-methods longitudinal cross-sectional study involving 51 participants and 229 assessments. Data collection included symptom questionnaires, biological sampling, brain imaging, and cognitive testing. Approximately 50% of those deployed reported high symptom burden, encompassing headaches, difficulty concentrating, fatigue, irritability, and memory deficits.
The symptoms aligned with post-concussion syndrome as identified by the Rivermead Post-Concussion Symptoms Questionnaire (RPQ).
Symptoms generally emerged within the first 6 months of deployment and persisted throughout follow-up. Risk factors for symptom development included female sex, a history of endocrine or metabolic disorders, and elevated anxiety scores. A multiple logistic regression model using these factors predicted symptomatic outcomes with 85.7% accuracy.
Biological analyses revealed elevated levels of C-reactive protein and thyroid stimulating hormone, along with decreased butyryl- and acetylcholinesterase activity during deployment. Cognitive testing identified impairments in spatial reasoning and multitasking. While clinical MRIs did not show overt pathology, some individuals demonstrated leaky blood-brain barriers and slowing of brain activity on MEG/EEG.These findings point to a potential environmental cause, with mass fumigation in Havana identified as a possible contributing factor.
The study contributes to the growing body of research examining acquired brain injuries from toxic exposures. The findings of this work could influence medical surveillance and pre-deployment health screening protocols of Canadian diplomats stationed in high-risk environments.