Νικολόπουλος Θωμάς, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ.
Κορρές Σταύρος, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ.
Κορρές Γεώργιος, Ακαδημαϊκός Υπότροφος, Ιατρική Σχολή, ΕΚΠΑ.
AVS is defined as the sudden onset of vertigo with nausea and / or vomiting, gait instability, and nystagmus lasting days or weeks. The symptoms are usually attributed to diseases such as vestibular neuropathy or labyrinthitis which are the main diseases of APV. However, observational studies suggest that up to 25% of patients with AVS may suffer from dangerous strokes that mimic APV. Studies also suggest that in the first 24-48 hours after the onset of symptoms, false-negative MRI may appear in patients with acute stroke. While classical description suggests focusing on cerebellar points for the diagnosis of acute stroke, some AVS presentations do not present with limb ataxia, dysarthria, or other obvious neurological features. HINTS is a 3-part test (Head Impulse test, Nystagmus, Test of Skew Deviation) and is designed to improve the sensitivity to detect stroke in patients with AVS.
A systematic review of the international literature was carried out. The search was done on the Pubmed and Cochrane Library search engines. The keywords used were acute and vestibular and syndrome and vertigo. The search was set in a time frame of 5 years (2015-2020). Reviews and systematic reviews were selected as filters. English was also introduced as a language filter.
Pubmed, advanced search, all fields, review, systematic review 2015-2020, 40 results. 37 were simple reviews and 3 were systematic reviews. 10 met the criteria. Cochrane library, all fields, 2015-2020 16 results. Only one study met the corresponding criteria similar with Pubmed search. Studies that did not meet the criteria for the differential diagnosis of acute vestibular syndrome were excluded because they were mainly referred to the differential diagnosis of the causes of dizziness. A total of 11 studies were included.
Following HINTS initial description for the diagnosis of AVS in 2009, there has been significant interest for the systematic evaluation of this triad of exams for the diagnosis of stroke and other less common central causes of AVS. Shortly after the initial description, more and more neurologists and neurotologists began using HINTS to evaluate AVS. This trend has increased with the availability of vHIT. Many authors report the contribution of vHIT in the diagnosis of patients with AVS. The reason is that it added quantitative information to the first clinical observations. The introduction of vHIT added a greater understanding of the complex interaction between the vestibular pathways, the brainstem, and the cerebellum. In addition, it allows the evaluation of the VOR at the level of all six semicircular canals, with precise localization of peripheral versus central lesions, often confirmed by brain imaging. Although therapists are increasingly dependent on MRI to diagnose acute stroke, a low sensitivity to stroke exclusion in an AVS patient in the first 24-48 hours after the onset of symptoms should be considered. Early MRI examination in the AVS appears to be of little sensitivity and it is reported that only imaging may miss the diagnosis by failing to detect of up to 50% of strokes within the first 24 - 48 hours of the onset of symptoms. One explanation is that structural changes delay to become visible on MRI in relation to the onset of symptoms. It is also possible for small vascular infarcts to cause a decrease in blood perfusion, capable of causing symptoms but not capable of causing changes in MRI.
Study on the need for differential diagnosis of vertigo in patients with AVS is observed in the international literature. Studies report that up to 25% of patients with AVS possibly have vertigo of CV etiology. The correct diagnosis in the ED will give the proper treatment to the patient suffering from CV vertigo and will not subject the patient with PV vertigo in unnecessary examinations. The HINTS test seems to strengthen its position in facilitating its differential diagnosis in AVS. However, the correct result is questioned based on the subjectivity of the examination. The examiner will judge what the result is. So his knowledge and experience play a role. It is difficult to rely entirely on his judgment based on clinical examination. Recording devices such as VOG or vHIT make the differential diagnosis clearer. It remains to be seen in the future, with the information of therapists who may examine a patient with AVS, as well as with algorithms for the differential diagnosis of vertigo in AVS, the increase of the rates of successful and timely recognition of C.V vertigo.
Acute, Vestibular, Syndrome, Vertigo