Havana Syndrome

Timothy C. Hain, MD • Most recent update: October 17, 2021

The notion of an “acquired neurosensory disorder” called the "Havana syndrome was introduced after reports emerged of individuals developing persistent neurological and audiovestibular symptoms after US government service in Cuba (Swanson et al, 2018; Hoffer et al, 2019). This syndrome, of which some are skeptical of its very existence (Bartholomew and Baloh, 2020) has been attributed to either sound or electromagnetic pulses. This exposure is currently based on speculation.

According to Hoffer et al (2019), "in the Autumn of 2016, diplomatic personnel residing in Havana began to present with symptoms of dizziness, ear pain, and tinnitus that emerged after perception of high frequency noise and/or a pressure sensation."

According to Verma et al (2019), "United States government personnel experienced potential exposures to uncharacterized directional phenomena while serving in Havana, Cuba, from late 2016 through May 2018. "

Symptoms of "Havana syndrome":

According to Hoffer et al (2019), "the majority of individuals reported intense ear pain in one or both ears and experienced tinnitus. All of the individuals noticed unsteadiness and features of cognitive impairment. On presentation to our center, dizziness (92%) and cognitive complaints (56%) were the most common symptoms"

Diagnosis of Havana Syndrome:

According to Verma et al, 2019, "Among US government personnel in Havana, Cuba, with potential exposure to directional phenomena, compared with healthy controls, advanced brain magnetic resonance imaging revealed significant differences in whole brain white matter volume, regional gray and white matter volumes, cerebellar tissue microstructural integrity, and functional connectivity in the auditory and visuospatial subnetworks but not in the executive control subnetwork. The clinical importance of these differences is uncertain and may require further study. " [Our thought is that separating the "chicken from the egg" might be difficult].

There has also been use of the same technology to track eye movements in concussion patients involving pupils and convergence, and reports that individuals with the "Havana syndrome" have differences in this measure. (Balaban et al, 2020). They reported "This report is a retrospective, quantitative analysis of video-oculography data of pupillary light reflex performance and binocular disparity-driven eye and pupil movements during the acute time period after the reported exposure. The patterns of response in these 19 individuals are markedly different than those seen in a group of individuals with the usual acute mild traumatic brain injury (17 subjects) and from 62 control subjects (21-60 years old) with no injury. Linear discriminant analysis was then used to identify a classifier for an objective discrimination of the groups with >91% accuracy and no confusion between the acute neurosensory findings among the members of the Havana diplomatic community and the subjects with acute mild traumatic brain injury. [We would like to see this replicated]

Abouzari et al (2020) proposed that the Havana syndrome was actually vestibular migraine. They stated "On regression analysis, the only feature which kept its significant difference between the two cohorts was acute intense head pressure (P = 0.007). The domains with similar occurrence ratios included dizziness, headache, light sensitivity, hearing reduction, and tinnitus. In other words, multiple headache and vestibular symptoms, consistent with VM criteria, were similar between the two cohorts. The considerable similarities across various domains between VM patients and Havana subjects could be due to migraine as a possible common etiology for both groups. We propose VM as a potential etiology for the symptomatology in the U.S. diplomats in Cuba."

Summary of data on Havana Syndrome:

The Havana syndrome is a set of symptoms, including dizziness, reported in US government personnel in Havana Cuba. As of late 2021, it is uncertain whether this condition can be distinguished from "functional" conditions or vestibular migraine. The quality of the evidence is low at present.