The acute onset of persistent vertigo with associated nausea/vomiting, gait instability, nystagmus, and head-motion intolerance defines AVS. These patients may or may not have associated deficits on neurologic examination [1]. This variant will address the imaging approach to those presenting with AVS but a normal neurologic examination (isolated AVS). The approach to those with associated neurologic deficits will be discussed as a separate variant (Variant 3). Patients with vertigo of any cause are often initially evaluated in the emergency department. Although the use of CT imaging performed for this indication has dramatically increased over the past several decades, the detection rate of contributory central nervous system pathology in those with a normal neurologic examination remains very low (<1% in an emergency department in a single center, which included 3,165 patients); see Variant 8 [25]. This is not surprising because many patients with acute vertigo and a normal neurologic examination will have a benign peripheral etiology. In patients with AVS and a normal neurologic examination, the most common causes of symptoms are vestibular neuritis and labyrinthitis, neither of which has associated findings on CT imaging. The most worrisome cause of AVS to be excluded is a posterior circulation infarct involving the brainstem or cerebellum; see Variant 3. Although the prevalence of cerebrovascular disease in all patients presenting to the emergency department with dizziness or vertigo is approximately 4%, the prevalence of cerebrovascular disease in those presenting with AVS is closer to 25% and may be as high as 75% in the highest vascular risk cohorts [26]. Depending on the skill and training of the examiner, focal neurologic symptoms/signs are reportedly lacking in between one-third and two-thirds of these patients [27].
Dizziness and Ataxia. The acute onset of persistent vertigo with associated nausea/vomiting, gait instability, nystagmus, and head-motion intolerance defines AVS. These patients may or may not have associated deficits on neurologic examination [1]. This variant will address the imaging approach to those presenting with AVS but a normal neurologic examination (isolated AVS). The approach to those with associated neurologic deficits will be discussed as a separate variant (Variant 3). Patients with vertigo of any cause are often initially evaluated in the emergency department. Although the use of CT imaging performed for this indication has dramatically increased over the past several decades, the detection rate of contributory central nervous system pathology in those with a normal neurologic examination remains very low (<1% in an emergency department in a single center, which included 3,165 patients); see Variant 8 [25]. This is not surprising because many patients with acute vertigo and a normal neurologic examination will have a benign peripheral etiology. In patients with AVS and a normal neurologic examination, the most common causes of symptoms are vestibular neuritis and labyrinthitis, neither of which has associated findings on CT imaging. The most worrisome cause of AVS to be excluded is a posterior circulation infarct involving the brainstem or cerebellum; see Variant 3. Although the prevalence of cerebrovascular disease in all patients presenting to the emergency department with dizziness or vertigo is approximately 4%, the prevalence of cerebrovascular disease in those presenting with AVS is closer to 25% and may be as high as 75% in the highest vascular risk cohorts [26]. Depending on the skill and training of the examiner, focal neurologic symptoms/signs are reportedly lacking in between one-third and two-thirds of these patients [27].