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CUB | Oct 3, 2021

Cuba responds to United States claims of “sonic attacks” against diplomatic staff-Part II

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The United States has drawn attention to a number of “sonic attacks” experienced by some of its diplomatic staff working in Cuba.

Cuba has released a scientific report rejecting that it was involved in these transgressions against U.S. diplomats.
Below is Part II of that report

Claim 2: Brain damage, originating during a sojourn in Havana, was found in all the employees

The claim that brain damage originated during the employees’ sojourn in Havana lacks scientific evidence.

 As discussed above, the first tier of evidence for this claim, the neuropsychological findings, has been discredited. A second tier would be neuroimaging findings (Verma et al., 2019). A third tier would be the oculomotor and vestibular findings claimed to demonstrate damage to the inner ear (labyrinth) by the UMiami team (Hoffer et al., 2018).

 Initially, Swanson et al. (2018) reported nonsignificant findings in conventional MRI neuroimaging of their cases. The subsequent article by Verma et al. (described by the authors as based on advanced neuroimaging methods) claimed: “Potential imaging-based differences between patients and controls with regard to (1) white matter and gray matter total and regional brain volumes, (2) cerebellar tissue microstructure metrics (e.g., mean diffusivity), and (3) functional connectivity in the visuospatial, auditory, and executive control subnetworks.”

 This was again assumed to be related to “directional phenomena” allegedly perceived by the cases. However, Verma et al. cautioned that “The clinical importance of these differences is uncertain and may require further study.”

There are severe problems with asserting that this study demonstrated that brain damage was found in U.S. employees linked to their stay in Havana.

  • ●  The first problem is that none of the “advanced” neuroimaging methods used in the study

has been accepted for routine use in clinical practice and assessment of patients. Accepted normative data are not available for these methods that allow deciding when an individual case deviates from normality.

  • ●  The findings depend critically on the comparison of patients with a control group of healthy persons. However, there is no guarantee that the selected controls were adequately matched to patients to exclude other causes of potential imaging-based differences. Stress, rehabilitation procedures, age, functional neurological disorders, all produce changes in neuroimaging studies (Arthuis et al., 2015; De Santis et al., 2014; Ejareh dar & Kanaan, 2016; Farrell et al., 2007; Li et al., 2015), and were certainly present in the patient but not necessarily the control group. This could have generated the potential imaging-based differences. A group of people that had visited Havana under the same conditions and not reported symptoms would have constituted a better control group, if matched in critical variables.
  • ●  The reported changes show no coherent pattern: some measures show abnormalities, others show “hyper-normality” (Verma et al., 2019), suggesting that whatever caused the symptoms damaged some parts of the brain but improved others. These results do not indicate any known pathophysiological (or combination of) mechanisms.
  • ●  The study design did not allow the authors to establish if any of the imaging-based differences between patients and controls originated during the sojourn in Havana. It is troubling that Verma et al. recognize that a subset of cases (12/40) had a pre-existing brain injury. After excluding this subgroup from the analysis, the statistical significance of the many of their reported results disappeared.
  • ●  There is a concern in the international neuroimaging community about the difficulty in replicating results, as well as the possibility of erroneous and variable findings due to changes or inaccuracies in the numerous computational processing steps involved in advanced neuroimaging pipelines (Button et al., 2013; Poldrack et al., 2017; Specht, 2020). This is a pertinent caveat for the Verma et al., 2019 study given the multiplicity of analysis pipelines that were used.

The international neuroimaging community was skeptical of the Verma et al. study as summarized in The Guardian https://www.theguardian.com/science/2019/jul/23/brain-scans- of- us-embassy-staff-to-cuba-show-abnormalities). Professor Paul Matthews (Imperial College London) said “This paper would not meet usual standards for publication, particularly in a high- profile journal… they do not correspond to known patterns of brain injury and could not be shown to have changed in the people before and after the exposure.” Professor Heidi Johansen-Berg (Wellcome Center for Integrative Neuroimaging, Oxford University) stated that the differences in the patients’ brains were not clear cut. It was impossible to say whether they were linked to a particular event, the precise pattern of changes was difficult to explain and it was not clear if or how they related to the patients’ symptoms. Professor Ray Dolan (Wellcome Trust Center for Neuroimaging at University College London), also cited in The Guardian article, opined that “Given what we know about functional specialisation in the brain one would expect meaningful relationships between the severity of specific deficits and the degree of change in brain regions that mediate specific functions…. The report is silent on this. I would take the findings with a pinch of salt.”

The Dalhousie group studied a sample of Canadian cases.

They reported alterations in white matter tracts in the posterior part of the corpus callosum and the adjacent part of the fornix (Friedman et al., 2019).

However, the same caveats apply to this study, which has many discordant findings with the UPenn results.

Interestingly, the NASEM report (page 15) concluded that: “the committee felt that none of the imaging studies performed so far were sufficient to serve as a basis for a case definition or management of individual subjects.”

The possible vestibular involvement in most employees was hypothesized basically because of subjective complaints, which are unreliable and nonspecific as indicators of injury since they appear in a long list of medical conditions (Strupp et al., 2020).

Among these are functional disorders such as persistent postural-perceptual dizziness (PPPD), a functional (not psychiatric) vestibular disorder that may be triggered by psychological conditions and which could explain chronic vestibular signs and symptoms in some patients (Popkirov et al., 2018).

Also, the UPenn team used a restricted battery of vestibular tests in a small number of individuals without control group assessments (Swanson et al., 2018).

Although the patients included in the UMiami study underwent a more extensive battery of vestibular function tests, very little information is available about protocols, equipment details, and normative data, which hampers proper interpretation.

Furthermore, these tests were performed only on the affected group. The comparisons of patients were with historical norms, based on healthy participants possibly were not matched adequately to the target group (Hoffer et al., 2018).

Therefore, these data derived from self-reported questionnaires and limited vestibular tests are insufficient to claim the presence of a homogeneous clinical entity nor vestibular damage.

The NASEM (page 14) committee concluded that: “the aggregate data derived from the subset of well-established clinical laboratory diagnostic tests presented by the four clinical groups performed weeks, months, or years after the initial onset did not identify a common pattern of structural injuries to the labyrinths or brains of patients that could explain the reported vestibular symptoms.”

The UPenn team reported a high incidence of subjective oculomotor symptoms (eyestrain and convergence insufficiency). Still, the lack of baseline assessments, control group, blind examiners, and the long time between the alleged attacks and the medical interviews are important limitations. Their use of the Convergence Insufficiency Symptoms Survey is questionable due to its low specificity for convergence insufficiency (Horan et al.,

2015). Also, they described saccadic and smooth pursuit dysfunctions based on the developmental eye movements test (D.E.M.), which is used in children but does not allow for quantifying saccade dysfunction. D.E.M. performance and quantitative measures of saccadic eye movements (using established oculomotor tests) are not correlated (Ayton et al., 2009).

 Not enough information about the protocols and equipment used for the oculomotor assessments are available in the case of the UMiami study, which did not report specific findings of optokinetic response and saccades. Notably, the Dalhousie team using well- established methods for oculomotor assessment found no significant impairments in their patient cohort.

Claim 3: A directed source of energy that could affect people’s brains from large distances after piercing physical barriers at homes or hotel rooms

Sound (audible; infra- and ultrasound)

The first hypothesis about directed energy sources causing the symptoms involved sound waves. Sound waves tallied with the auditory sensations reported by the affected individuals and with the existence of sound-based weapons used to disperse crowds (see below).
The F.B.I. supplied recordings of the strange sounds allegedly heard by U.S. employees to the Cuban Government for their study. However, after some research, the idea of sound-based weapons was discarded. First, as reviewed above, it was impossible to substantiate in most patients hearing loss (a natural consequence of exposure to loud sounds).

The only cases reported had pre-existing hearing loss. Second, there is no scientific report of sound causing brain damage, and to this it would have to produce devastating damage to the middle and inner ears. Third, to damage the ear sounds must be higher than 120 dB, which would have been clearly audible to any person nearby (of which no reports were ascertained despite extensive search). Fourth, recordings made by the diplomats of the alarming noises they heard were leaked to the press and posted by Associated Press online (https://www.youtube.com/watch?v=rgbnZG85IRo).

When they were analyzed by a team of biologists from the U.S. and U.K., the grating noise they contained was identified as the mating call of the West Indies short-tail cricket (Stubbs, 2019). This team also analyzed the recordings supplied by the U.S. to the Cuban Government and found that they also contained calls from  the same species of cricket, recently described as endemic to Cuba (Yong, 2019). This result is in agreement with a previous Cuban study (Barceló-Pérez & González, 2018).

Other researchers (Yan et al., 2018) suggested that the sounds perceived by embassy staff were by-products of ultrasonic listening devices. However, ultrasound cannot produce brain damage unless the source is very close to the head since it rapidly dissipates with distance.

Moreover, ultrasound would be challenging to focus on a single target, and those was also discarded as a cause for damage. The possibility of infrasound was examined since adverse health effects have been described after exposure (Lubner et al., 2020; M. Y. Zhang et al., 2016). However, several aspects have led to discount its use as a weapon.

Among other factors, the large size of the infrasound generators and associated power supplies, the difficulty in concentrating their emissions, and its extremely long wavelengths compared to the target object’s size make it an unlikely weapon. The Journal of the Acoustical Society of America published a critical review of ultrasound and other types of sound in the case of U.S. diplomats (Leighton, 2018) that rejected their contribution to the reported health effects.

Radiofrequency (R.F.) and microwaves

The NASEM report concluded (page 2): “Overall, directed pulsed R.F. energy, especially in those with the distinct early manifestations, appears to be the most plausible mechanism in explaining these cases among those that the committee considered.” R.F. in this quotation refers to radiofrequency.

This conclusion is puzzling because the report cites no direct evidence for the involvement of R.F. in the events in Havana or elsewise. Moreover, the report’s discussion of the scientific literature contradicts this idea in several of its paragraphs (page 21). For example: “…While there are several studies on the health effects of continuous wave and pulsed R.F. sources, there are insufficient data in the open literature on potential R.F. exposure/dosage characteristics and biological effects possible for DoS scenarios. …” In the absence of such data, it is difficult to align specific biophysical effects within the potential R.F. exposure regime that could explain specific medical symptoms reported by DoS personnel and the variability in specific experiences and timelines of individuals.”

The NASEM report indicated that symptoms such as dizziness, headache, fatigue, nausea, anxiety, cognitive deficits, and memory loss are “consistent with known R.F. effects.” A recent article (Golomb, 2018) also argued that exposure to R.F. (presumably long-term continuous waves) produces symptoms that overlap the complaints of the U.S. employees.

 The problem is that this constellation of symptoms is unspecific, and by the same logic could also be identified with other well-known syndromes that share the same symptoms (i.e. small vessel Cerebrovascular disease, cranial trauma, Meniere’s Disease, stress disorders, “Gulf War syndrome“). The latter are not attributable to R.F. exposure. Most decisively, this conclusion is inconsistent with dozens of high-quality, double-blind experiments carried out with human volunteers. Systematic reviews of these studies have not provided evidence for a relation between the R.F. exposures and the symptoms or physiological responses that might explain embassy staff health complaints (Dongus et al., 2021; Zhou et al., 2020; ) (see also http://www.ices-emfsafety.org/expert-reviews/).

 Similarly, observational studies (e.g. Elwood, 2012) have not find health effects related to alleged long-term R.F. exposures in the U.S. Moscow embassy incidents from decades ago.

Persuasive evidence for adverse health effects of microwave energy (within international exposure limits) has not been found in many authoritative reviews. This includes surveys of research in the former Soviet Union (Pakhomov & Murphy, 2000), careful assessments by Western expert groups (Scientific Committee on Emerging Newly Identified Health Risks., 2015), and international guideline committees (Vecchia, et al., 2009) A recent review reaches the same conclusion (Foster & Vijayalaxmi, 2021).

 While “nonthermal” microwave interactions with biological materials do exist, the required field levels are far beyond anything plausibly present (or producible) in ordinary environments (including those related to the Havana health complaints). These effects would be very damaging due to tissue heating (Foster, 2000).

Even animal experiments on R.F./microwave-induced damage to the brain have mainly produced negative results for the purposes of this review. The few observed effects have been obtained under extreme conditions not relevant to the incidents described by the U.S. employees.

The experimental setups require keeping constant the geometry between the experimental subject heads and a nearby electromagnetic wave source. Firmly fixing the subject’s position near the R.F. source obviously does not apply to health incidents of interest. Even so, the described effects are inconsistent and weak. A recent study (De Seze et al., 2020), with apparent effects, examined animals subjected to an intense exposure (above anything the diplomats could have experienced) with high-power, short-duration microwave pulses (3.7 GHz, 2 G.W./m2, 2.5 ns pulses, 100 pulses/sec for total of 14 min, 22 W/kg). They found an increased prevalence of cancer and a decrease in survival time. They also observed evidence of brain inflammation.

 However, the exposures included significant X-ray components, which probably caused the pathological effects. There were some behavioral effects; apparently, the animals avoided exposure. One cause of this could have been time- averaged exposure levels that were thermally uncomfortable. Even this does not fit reports from the DoS cases who did not experience thermal sensations.

The NASEM report argued that pulsed R.F. exposures could have caused the sounds perceived by embassy staff (and their directional dependence). The well-documented (Frey, 1961) “microwave hearing phenomenon,” or “Frey effect,” inspired this idea. This effect is thought to arise as follows: the R.F. pulse provokes a transient temperature rise in the head, leading to thermal expansion, which launches an acoustic wave. Thus, subjects perceive “clicks” every time an R.F. pulse (e.g., 27 μs, 2.45 GHz pulses, 53 kW/m2) is absorbed in the head (Foster & Finch, 1974). The acoustic pressures in the typical Frey effect are many orders of magnitude too weak to cause tissue damage. People perceive audible sensations only because of the exquisite sensitivity of the human auditory system (Foster et al., 2018). Therefore, the Frey effect is a poor fit to what the U.S. employees described.

The sounds induced by pulsed microwaves are weak, even with the head exposed next to the emitting antenna they are audible only in a very quiet environment. Furthermore, it is not possible to localize in space these acoustic waves generated inside the head. Therefore, they cannot be “directional” (i.e., perceived as coming from a defined source). The U.S. employees reported sounds, and other related sensations, as originating from a particular direction, which is inconsistent with the Frey effect. This effect cannot be registered outside the head; in this case the recordings supplied by U.S. sources would be irrelevant.

The NASEM panel hypothesized short, intense microwave pulses as a cause of the health complaints. Damage thresholds increase for short pulse duration. Extrapolating from available data, Kenneth Foster (UPenn) concluded that nanosecond microwave pulses do not appear capable of producing tissue damage at feasible exposure levels that would not also be thermally damaging (Foster et al., 2016; Foster and Chou, 2021). Brain damage without skin injury is improbable. U.S. employees did not report sensations of warmth. Medical examiners did not find evidence of any type of burns (Hernandez-Caballero, 2021). Citing the Havana incidents, a recent article models the head/brain with finite-element methods (Dagro & Wilkerson, 2021).

 This article concluded that: “Although the simulations show that injury thresholds could be exceeded in the case of rapidly applied large temperatures (e.g., 6 ◦C acheived in 1 μs), it is unlikely that a microwave source could generate such a large temperature increase in these short timescales”. Moreover, a 6 ◦C degree increase in temperature affecting the skin is clearly noticeable. Other attempts to model the hypothesized (but undemonstrated) microwave damage to ear and brain also require unrealistic assumptions about the R.F. sources (Lin, 2021).

Additionally, electronic equipment should have been interfered with or even disrupted by R.F. fields at the level where microwave hearing would elicit the sensation of “a loud sound”. Interference with existing telecommunications, Bluetooth headsets for phones, and Wi-Fi systems (which operate in low GHz frequency bands), would also have been expected if very intense microwaves were used (Foster and Chou, 2021; Foster et al., 2015; Repacholi, 2020). However, none of the people describing the strange sounds they linked to their health complaints testified that interference with electrical devices was happening simultaneously (Hernandez-Caballero, 2021).

Notably, the Cuban police interviewed neighbors of the U.S. employees, of workers at their homes, or workers at the “Nacional” and “Capri” Hotels (implicated in some complaints). These interviews did not uncover sightings of suspicious individuals, unusual equipment, or experience of strange sounds during the times the alleged “attacks” were taking place.

These locations are open and frequently visited areas (Hernandez-Caballero, 2021). These findings place severe constraints on the possibility of positioning equipment capable of generating high- energy sound or microwave beams at the locations where the events allegedly took place.

A summary of factors that decrease the plausibility of the sounds perceived by embassy staff being due to microwave hearing (from Repacholi, 2020) include:
Massive peak and average microwave power densities would be needed to elicit the sensation of “a loud sound”. This would require large microwave generating equipment, such as military radars, used close to the target.
Embassy staff did not report any thermal sensation that high microwave average power densities would cause.

  • ●  There were no reports of electromagnetic interference that would undoubtedly result from exposure to such high peak power densities.
  • ●  The reported directional nature of the sound does not fit the description of the microwave hearing effect.
    It is unfortunate that the NASEM committee did not consult more experts on the

biological effects of R.F. and microwaves and that its conclusions are inconsistent with the literature they reviewed. International and Cuban experts reject the microwave hypothesis for the Havana health complaints.

Claim 4: A weapon capable of generating such a physical agent is realizable and identified.

Sound or microwave weapons already exist, which has fueled the argument that someone used them in Havana. For such weapons to be feasible in the scenarios of the alleged attacks, they would have to fit into spaces and landscapes surrounding the settings of the incidents without having attracted the attention of neighbors or other hotel guests, or the U.S. Embassy security.

Also the energy produced should be able to penetrate the physical barriers at the homes and hotel rooms and be capable of selective directional beaming to affect specific individuals. We examine two well-known examples.

The first example is the Long Range Acoustic Devices (LRAD) that uses intense, disturbing sounds for crowd control (https://www.asha.org/News/2020/Long-Range- Acoustic- Devices-for-Crowd-Control-Can-Cause-Serious-Hearing-Loss-and-Harm/). These are large truck-based, blatantly noticeable equipment that produces indiscriminate effects on many people in large areas. They do not fit the scenarios in which the alleged attacks took place, which in conjunction with the implausibility of sound damaging the brain or labyrinth without inducing severe hearing loss, disqualifies their involvement in the events of interest. The other example is the Tactical High Power Operational Responder (THOR) developed by the United States Air Force Research Laboratory (https://afresearchlab.com/technology/directed- energy/successstories/counter-swarm-high-power-weapon/). This device produces high- energy microwave bursts to disable drones. Nevertheless, in addition to its large size which would have made it noticeable, it would have generated disruption of electronic devices, factors absent from the alleged incidents in Havana.

There have been reports of attempts to create smaller mobile microwave and infrasound weapons in Russia, the U.S., China, and Israel. However, what is known about these devices is inconsistent with their use for alleged events in Havana (IEEE Philadelphia Section, IEEE Philadelphia SSIT Chapter, IEEE UK, and Ireland SSIT Chapter & SIGHT, 2021). A significant difficulty in developing these weapons is related to their size and power requirements.

Claim 5: Evidence is unearthed that an attack has taken place.

This facet is outside of the purview of this report, and we refer readers to the accounts by the F.B.I., Royal Mounted Police, and Cuban police investigations, which found no evidence of an attack that could cause the reported symptoms. They concluded that sound, ultrasound, and infrasound could not be used for attacks (Hernandez-Caballero, 2021). The field studies carried out by the Cuban Expert Group, which interviewed dozens of neighbors of the U.S. employees’ homes and workers at the hotels, is relevant. As stated above, none of the interviewees referred to the observation of unusual equipment or activities during the periods of interest (Hernandez-Caballero, 2021). It is interesting to note that during the same time that alleged attacks were taking place at the “Nacional” Hotel, an international symposium organized by the Kavli Foundation was taking place at that venue, with the participation of prestigious U.S. and European researchers, including a Nobel prize winner.

Also pertinent to this point are the few occasions that Cuban medical professionals had the opportunity to examine foreigners concerned about unusual sounds and possible health effects. In all cases, the investigators found a trivial explanation for the “unusual” sounds and excluded the possibility of their causing adverse health effects. For example, a foreign diplomat reported symptoms and was worried about strange sounds. When examined at the International Clinic “Cira Garcia” in Havana, the diagnosis was barotrauma caused by sea diving. In this case, police from the country of the diplomat and Cuban Police jointly investigated the strange sounds and agreed that a nearby air conditioning compressor was their origin (Hernandez-Caballero, 2021). These examples illustrate the power of the media and of declarations of U.S. government officials in inducing anxiety about “mystery attacks,” resulting in what probably is a psychogenic amplification of symptoms caused by unrelated and mundane health issues.

Claim 6: Available evidence falsifies alternative medical explanations

Psychogenic and functional neurological disorders

Several letters to the Editor of JAMA -after the first UPenn report- suggested the possibility of psychogenic factors and functional neurological disorders as triggers of the neurological symptoms reported by the patients. In one of these letters, Robert Bartholomew (2018) provided arguments supporting mass psychogenic disorder in U.S. diplomats by observing that the victims were from the same social network. Mass psychogenic disorders are defined as: “the rapid spread of illness signs and symptoms affecting members of a cohesive group, for which there is no corresponding organic etiology” (Bartholomew et al., 2012; Bartholomew & Wessely, 2002).

 Outbreaks of psychogenic illness have resembled neurological diseases such as epilepsy, Giles de la Tourette syndrome, and sensory disorders. When investigating suspected outbreaks of psychogenic illness and kindred phenomena, it is crucial to focus on the social context underpinning the beliefs instead of the symptoms per se (Bartholomew & Pérez, 2018).

The affected individuals, in this case, formed a closely-knit community, largely isolated from the local population, in the context of a long history of a difficult relationship between the United States and Cuban governments. The two countries had reestablished diplomatic relations only recently before the incidents began (Bartholomew, 2018), and the new administration had made clear its intentions of reversing this development. The UPenn team rejected any role for psychogenic or sociogenic factors. However, even the NASEM committee recognized that psychogenic factors and functional neurological disorders might have played a role in exacerbating, and spreading over time, the symptoms experienced by the diplomats.

Significantly, the committee stated that it could not rule out the possible involvement of psychogenic disorders as they had “received no epidemiological evidence about patterns of social contacts that would permit a determination about possible social contagion.”

This claim is mystifying because the social patterning of the spread, which was conspicuously limited to U.S. and Canadian embassy staff and their families, was documented in two widely circulated publications that appeared well before the release of the NASEM report (Golden & Rotella, 2018; Baloh & Bartholomew, 2020).

It is also necessary to consider the possible role of functional neurological disorders in the health incidents of interest. These are real neurological disorders that produce objective signs of brain dysfunctions but are mainly triggered by psychogenic factors (Fobian & Elliott, 2019). Stone and colleagues (Popkirov et al., 2019) called attention to persistent postural perceptual dizziness (PPPD), a recently defined functional neurological disorder, as a good fit to the symptoms described by the U.S. employees.

Its core symptoms are unsteadiness and dizziness (Popkirov et al., 2018), together with susceptibility to motion stimuli, cognitive disturbances, and fatigue. Consistent with this hypothesis, the N.I.H. team diagnosed PPPD in 25% of patients that they studied. Another article (Abouzari et al., 2019) that reviews the published data concluded that most patients in the Havana incidents met the International Classification of Headache Disorders criteria for vestibular migraine, which can overlap with PPPD. Likely triggers for vestibular migraine are stress and lack of sleep (Sohn, 2016), reported (Swanson et al., 2018) for many diplomats.

Toxic etiology

Toxic chemical agents were posited as a plausible cause of the health incidents after Canadian researchers found increased blood levels of temephos and pyrethroid metabolites, and decreased cholinesterase activity, in some Canadian diplomatic staff and tourists.

 These people had stayed in Havana during the same period as the U.S. diplomats involved in the health incidents (Friedman et al., 2019). A possible source of this intoxication was the widespread spraying of these chemical agents as insecticides against the mosquitoes causing Zika disease.

Their clinical, electrophysiological, and neuroimaging assessments revealed spatial memory impairments, abnormal brain-stem auditory evoked potentials, abnormal paroxysmal slowing events in the E.E.G., and some neuroanatomical alterations (Friedman et al., 2019) in a group of cases. Previous work as shown that subacute or chronic exposure to pesticides can produce neuropsychological impairments (Rohlman et al., 2016; Sánchez- Santed et al., 2016; Zhang et al., 2016). Scientific collaboration is underway to replicate these findings in a cohort of Cuban subjects highly involved in this spraying campaign. However, this explanation does not seem to cover alleged health incidents in other countries.

The NASEM report (page 24) discarded chemical intoxication in the U.S. diplomat staff because: “…there is no convincing evidence of acute high-level exposures and the clinical

history of affected U.S. Embassy personnel is not consistent with acute organophosphate poisoning.” Nevertheless, they did not rule out that the combination of pesticides and psychosocial or physical stressors can have a role in triggering some symptoms. It is disconcerting that the NASEM report ruled out the toxin hypothesis (despite the evidence found in some cases), whereas it accepted the R.F. hypothesis (for which there is absolutely no evidence in any case).


The evidence asserted to support the “mystery syndrome” narrative is not scientifically acceptable in any of its components. Numerous scientific publications, expert opinions, and studies on the ground in Havana contest or refute the presented evidence. Most of the claims that apparently support the narrative were even discounted by the NASEM standing committee itself, except for their perplexing endorsement of a pulsed microwave agent as the cause of the U.S. diplomats’ health complaints (despite not being sustained by the evidence they reviewed). International and Cuban experts dismiss the microwave weapon idea as incompatible with the Havana events and established science.

The “mystery syndrome” narrative has survived due to a biased use of science, in which discrepant views have been suppressed, and published evidence “cherry-picked” to reinforce a narrative. Media and politicians have built on and amplified this false scientific narrative. We must explore simpler, less esoteric explanations to get closer to the truth. Due to a lack of information, CAS cannot know what happened to the U.S. employees during their sojourns in Havana. However, based on the reports from the U.S. and Canada and field studies carried out in Havana, CAS can offer a counter-narrative that challenges each of the claims reviewed above.

Counterclaim 1: It is possible that some U.S. employees while stationed in Havana felt ill due to a heterogeneous collection of medical conditions, some pre-existing before going to Cuba (e.g., ear trauma due to military service), and others acquired due to mundane causes such as age-related diseases, head trauma due to sports activities, and stress among many other possibilities. Thus, a heterogeneous collection of people misattributed their symptoms to a common external cause. The idea of a non-homogenous set of cases is implicit in the C.D.C., N.I.H., and NASEM reports.

Counterclaim 2: Only a minority of these cases present noticeable brain dysfunction, most due to experiences before their stay in Havana (caused by naturally acquired prevalent diseases or by head trauma), and others due to the previously mentioned functional neurological disorders. The international scientific community and the NASEM report dismiss most of the evidence presented to claim widespread brain damage in the U.S. employees. Other diseases prevalent in the general population can explain most symptoms.

Counterclaim 3: No known form of energy can selectively cause brain damage (with laser-like precision) under the conditions described for the alleged incidents in Havana. The laws of physics that govern sound, ultrasound, infrasound, or radiofrequency waves (including microwaves) do not allow this, as was recognized by U.S. and international experts. These forms of energy could not have harmed brains without being felt or heard by others, without disrupting electronic devices in the case of microwaves, or producing other lesions (like burst eardrums or skin burns).

Counterclaim 4: Although there are weapons that use sound to disperse crowds, or microwaves to disrupt drones, they are large and there is no possibility that this type of weapon would not go unnoticed (or leave a trace) if deployed in Havana. Furthermore, they cannot produce the person-selective effects described for the alleged incidents.

Counterclaim 5: Neither the Cuban police, F.B.I., nor Royal Canadian Mounted Police, have uncovered evidence of “attacks” on diplomats in Havana despite intense research.

Counterclaim 6: It is not possible to rule out the psychogenic and toxic explanations for many symptoms in some cases without further research. Specifically, all the conditions for psychogenic propagation of malaise were present in this episode.

Concerning the last counterclaim, we offer the following scenario: initially, -for whatever reason- a few individuals believed they were being “attacked” by “sonic weapons”. Subsequently, an environment was created that fostered amplification of symptoms and their misattribution to improbable causes, together with a psychogenic spread of concern and the development of functional neurological disorders. The factors that created this environment were an inadequate initial medical response, the early official U.S. government endorsement of an “attack” theory, and sensationalist media coverage, among other causes.

CAS is willing to revise its conclusions if new evidence emerges. It welcomes attempts to disprove its counterclaims in an atmosphere of open scientific collaboration. However, it firmly rejects as an “established truth,” a narrative built on flimsy foundations and faulty scientific practice. Each link in the chain of reasoning leading to the “mysterious syndrome” narrative is weak, so they cannot bolster each other. Additional flawed research cannot buttress the narrative. Unfortunately, farfetched speculations in some scientific fields (say neuropsychology, neuroimaging, or biomechanical modeling) are offered because they were “suggested” by other -unvalidated- conjectures.

An example is the idea that an “attack took place, which is accepted without critical thinking. Some science articles -and most news stories- we have read accept as an axiom that attacks occurred in Havana, thus an idea to build theories on. Nevertheless, after four years, no evidence of attacks has emerged. It is time for a restart of the narrative.

The CAS Expert Group deplores the lack of adequate patient medical information to carry out its work and the artificial restrictions imposed on collaboration with U.S. researchers involved in patient assessments. We sympathize with the plight of U.S. employees (or their families) that have health complaints. Since we recognize that people have been feeling ill, we think it is ethically imperative to dispel wild conspiracy theories and misattribution of symptoms to explanations that defy the laws of physics. Accomplishing the goal of cooperation and collaboration between U.S. and Cuban researchers would be a solid step to accelerate the recovery for many people affected by these incidents (Stone, 2014).

CAS reiterates its willingness to collaborate with NASEM and any other U.S. or international counterparts, with the goal of better understand the health incidents involving U.S. diplomats and their families in Havana (or in any other place). Ultimately, we hope this would help alleviate suffering in affected individuals and contribute to re-establishing closer ties between the two scientific communities and eventually between the two countri


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