- Published on 27 February 2017
“Our current knowledge allows for differential diagnoses to establish, with full certainty and without using sophisticated technology, whether peripheral or central causes lie behind cases of acute vertigo,” points out Sergio Carmona, an Argentinian specialist invited to by AMCAOF to its congress in Nayarit.
Sergio Carmona is probably one of the most influential otoneurology experts in Argentina, thanks to his contributions to the study and treatment of vertigo and balance disorders. We took the opportunity of talking to him prior to his participation as a speaker at the coming congress of the Mexican Association of Communication, Audiology, Otoneurology and Phoniatrics (AMCAOF), which will be held in Nayarit, and where this doctor’s presentation will cover acute vestibular syndromes, specifically those related to central vestibular syndromes, their treatment, and their evaluation in A&E services. To begin with, Dr. Carmona explains that “in line with the new definition put forward by the Bárány Society, acute vestibular syndrome (AVS) consists of an acute vertigo profile, along with signs and symptoms that suggest that the vestibular has been compromised. Patients can present with involuntary and uncontrollable eye movement, known as nystagmus, and difficulty in coordinating movements, known as ataxia; they can also present nausea and vomiting. All of these symptoms can last hours or days.”
Continuing on the specific question of central vestibular syndrome (CVS), he explains: “in the context of acute vestibular syndrome, the lesion affects the vestibular structures of the cerebellar vermis or the lateral surface of the brainstem, in general produced by a CVA (cerebrovascular accident). In terms of the symptoms, this type of disorder cannot be distinguished from the more frequent, benign form caused by a virus and known as vestibular neuritis.”
For professionals, “the difference is crucial, not just because of the obvious reason that it is not the same to suffer a CVA as a viral illness, but also because a CVA of the posterior fossa produces, in one-third of cases, malignant edema with high mortality.”
According to different epidemiological data, between 70 and 80 percent of acute vestibular syndromes are due to vestibular neuritis, and one quarter to central causes, this expert underlines.
With the definitions clarified, this is what Dr. Sergio Carmona (S.C.) had to say to Audiology Worldnews:
AWN. How are these syndromes approached in different groups of patients, such as diverse age groups and other specificities?
S.C. Special care must be taken when acute vestibular syndromes present in patients over 50-years-old or in those with vascular risk factors, i.e. high blood pressure, smoking, obesity, dyslipidemia, and diabetes. Not in any case should this lead to a false sense of security since in several recent research studies (e.g. in Carmona et al.,Frontiers in Neurology, published in August 2016), it has been shown that age difference between CVA and neuritis groups is only five years, among other reasons because artery dissection occurs in young adults.
AWN. What happens in the case of misdiagnoses, if they do occur?
S.C. Epidemiological studies in the USA (Newman-Toker et al) show that diagnostic error in patients with vertigo and CVA is five times more prevalent than in other forms of CVA which produce, for example, paralysis or speech difficulties. This means there is higher morbidity, in other words there are more consequences in the CVA with vertigo group, as well as higher mortality, which constitutes a major health problem.
AWN. How can this be effectively tackled?
S.C. Since 2009, two US neurologists, Doctors Newman-Toker (Johns Hopkins, Baltimore) and Jorge Kattah (Peoria, Illinois) have published clinical protocols that, based on three simple, ocular clinical signs, show high sensitivity and accuracy in separating central-cause AVS cases from peripheral-cause cases. This protocol is known by the acronym “HINTS”.
In fact, this protocol calls for specific clinical training not always undergone by physicians on call, and this is why our group developed a protocol based on observing patients’ progress, one which obtains the same degree of sensitivity, although with less accuracy than HINTS. It is a protocol that can be carried out by paramedic staff, more common in some services.
AWN. What happens in CVS cases in A&E services at state hospitals? Is there any difference in the handling compared to private centres?
S.C. In my opinion, it is more probable that diagnosis will be carried out in a teaching hospital; in fact, our work was carried out at the Cullen University Hospital in the city of Santa Fe. One of the problems in private centres is that they carry out computerised axial tomography scans (CAT) in emergency services with equipment of low or zero sensitivity, which leads to a false sense of security.
AWN. How does Argentina compare with other countries in the region with regard to these syndromes?
S.C. Although Argentina has a well-developed neurotology profession, we are a long way from solving this health problem, so it is necessary to create awareness and educate non-specialists. Training medical staff is key to progress in studying these types of pathologies, while our current knowledge allows for differential diagnoses to establish, with full certainty and without using sophisticated technology, whether peripheral or central causes lie behind cases of acute vertigo, so it is a question of awareness and medical training.
"Experience cannot be ad-libbed"
The credentials of Dr. Sergio Carmona provide full accreditation for his participation not just in the AMCAOF congress but in others of similar international status.
Carmona is a lecturer and doctor, a specialist in otoneurology, a branch of medicine that involves both otorhinolaryngologists and neurologists, and his special focus is the study and treatment of vertigo and balance disorders. He is the author of the most important work in Spanish on acute vestibular disorders, entitled Neuro-otología, published by Akadia, Buenos Aires, in 2010. During his career, he has built up a working group comprising doctors and technical staff with vast experience in handling the difficulties of vertigo, along with whom he has published more than 100 international papers, all on his specialty.
This outstanding professional is an honorary member of the Bárány Society; he also works as a lecturer in neurophysiology at Rosario National University in Santa Fe province. In addition, he is a member of the Ineba medical body, one of the main specialist centres in neurology in Argentina, located in Buenos Aires.
Read the article in Spanish on Audio Infos Latin America #55: