Truncal Ataxia in the Differential Diagnosis of Acute Vestibular Syndrome

In recent years we have witnessed great advances in the evaluation of patients with acute vestibular syndrome (AVS), not only as regard diagnostic technology but also as recognizing the importance of the patient’s report and physical examination. It has also been shown that physical examination is often more accurate than neuroimaging in the diagnosis of an injury at the level of the central vestibular system during the first hours of the event.
Since 2009 Kattah et. al. published the HINTS protocol. This has improved diagnostic accuracy. Although its application seems simple, in practice it is not so, since it requires an extensive training in order to master the diagnostic maneuvers.

In 2016, we published a retrospective case-control study: 114 patients with AVS, 72 of them with vestibular neuritis, 32 with PICA infarcts and 10 with AICA infarcts where we set out to evaluate whether truncal ataxia, as defined by Lee., et al. criteria was useful in the differential diagnosis of acute vestibular syndromes. We found that the presence of Grade 2 - 3 truncal ataxia has a sensitivity of 92.9% and a specificity of 61.1% to discriminate between central and peripheral lesions. No patient with a central lesion was free from ataxia, so its absence leads us to the diagnosis of a peripheral vestibular syndrome. No patient with vestibular neuritis presented Grade 3 ataxia, so their finding would confirm a brainstem injury. We also found that Babinski’s flexor asynergy was present in all patients with Grade 3 ataxia, and in all patients with Grade 1 stroke and ataxia. In this study, the combination of two signs,such as Grade 2 - 3 truncal ataxia with the characteristics of a central type nystagmus obtained a 100% sensitivity and a 61.1% specificity, so that no patient with a central vestibular syndrome would to be classified as a patient with peripheral lesion.