In one study, 11% of patients presenting with acute persistent vertigo but no focal neurologic symptoms/signs were found to have an acute infarct on CT or MRI of the brain [28]. Other studies estimate that 75% to 80% of patients presenting with AVS related to infarct have no associated focal neurologic deficits [29]. Isolated AVS is most commonly due to a benign peripheral cause; however, a lack of associated neurologic deficits does not exclude a central cause such as infarct. To address this, various bedside tests like the HINTS examination Dizziness and Ataxia have been developed to distinguish AVS of benign cause from posterior circulation infarct. When performed by specially trained practitioners, these tests have been shown to be even more sensitive than early MRI for the detection of infarct (100% versus 46%) [30]. Similar testing performed by nonexperts has shown more mixed results [6,31]. In another retrospective study involving 610 patients in an emergency department, not a single patient with an AVS, in whom the complete HINTS triad was consistent with peripheral vertigo, had abnormalities on CT/MRI [6]. Multiple sclerosis involving the brainstem or cerebellar peduncles is an additional but rare cause of AVS, accounting for approximately 4% of cases. Of note, nearly all of these patients also have additional abnormal neurologic findings suggesting a central lesion [32]. Even rarer causes of isolated AVS include cerebellar hemorrhage and a variety of autoimmune, infectious, and metabolic conditions [25]. Vestibular migraine may mimic a variety of causes of dizziness/vertigo, including AVS, but often has associated headache and other migrainous features (ie, photophobia, phonophobia, visual aura) [22,33]. Imaging is not required to diagnose vestibular migraine. To summarize, patients with isolated AVS may not require imaging if HINTS examination by specially trained providers is available and negative; otherwise, imaging may be required to rule out stroke.
Dizziness and Ataxia. In one study, 11% of patients presenting with acute persistent vertigo but no focal neurologic symptoms/signs were found to have an acute infarct on CT or MRI of the brain [28]. Other studies estimate that 75% to 80% of patients presenting with AVS related to infarct have no associated focal neurologic deficits [29]. Isolated AVS is most commonly due to a benign peripheral cause; however, a lack of associated neurologic deficits does not exclude a central cause such as infarct. To address this, various bedside tests like the HINTS examination Dizziness and Ataxia have been developed to distinguish AVS of benign cause from posterior circulation infarct. When performed by specially trained practitioners, these tests have been shown to be even more sensitive than early MRI for the detection of infarct (100% versus 46%) [30]. Similar testing performed by nonexperts has shown more mixed results [6,31]. In another retrospective study involving 610 patients in an emergency department, not a single patient with an AVS, in whom the complete HINTS triad was consistent with peripheral vertigo, had abnormalities on CT/MRI [6]. Multiple sclerosis involving the brainstem or cerebellar peduncles is an additional but rare cause of AVS, accounting for approximately 4% of cases. Of note, nearly all of these patients also have additional abnormal neurologic findings suggesting a central lesion [32]. Even rarer causes of isolated AVS include cerebellar hemorrhage and a variety of autoimmune, infectious, and metabolic conditions [25]. Vestibular migraine may mimic a variety of causes of dizziness/vertigo, including AVS, but often has associated headache and other migrainous features (ie, photophobia, phonophobia, visual aura) [22,33]. Imaging is not required to diagnose vestibular migraine. To summarize, patients with isolated AVS may not require imaging if HINTS examination by specially trained providers is available and negative; otherwise, imaging may be required to rule out stroke.