In a study of emergency department patients with dizziness, combined neurological symptoms with an OR of 16.72, P < . 01, was found to be the strongest predictor of a lesion positive on MRI [37]. In a cross-sectional study of 190 high-risk patients with dizziness, HINTS examination outperforms ABCD2 risk scores [30]. The diagnostic yield for head CT ordered in the emergency department for acute dizziness is low (2.2%; 1.6% for emergent findings), but MRI changes the diagnosis up to 16% of the time, acutely in 8% of cases [2]. Earlier MRI studies in posterior fossa stroke showed a high false-negative rate on DWI when performed within the first 24 hours of symptom onset [44,45]. This has improved with better imaging techniques over time. MRI has a higher sensitivity for acute ischemic strokes than CT, although within the first 48 hours DWI still can be falsely negative in approximately 50% of small ischemic strokes in the posterior fossa [6,46]. Some have advocated for delayed MRI (3-7 days) if initial imaging was negative [1,29]. One single-center study of 36 patients with basilar artery occlusion found DWI MRI helps predict outcome in basilar artery occlusion patients treated with intra-arterial thrombolysis [47]. Variant 4: Adult. Chronic recurrent vertigo. Associated with unilateral hearing loss or tinnitus. Initial imaging. In contrast to an isolated episode of acute vertigo, chronic recurrent vertigo suggests an intermittently symptomatic long-standing condition. When associated unilateral hearing loss or tinnitus is present, the diagnosis of MD should be considered. MD is of unknown etiology. Patients have intermittent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus, and aural fullness. Previously a purely clinical diagnosis, imaging in MD has increased in the past decade. It is associated with endolymphatic hydrops (distension of labyrinthine structures). Imaging may also Dizziness and Ataxia
Dizziness and Ataxia. In a study of emergency department patients with dizziness, combined neurological symptoms with an OR of 16.72, P < . 01, was found to be the strongest predictor of a lesion positive on MRI [37]. In a cross-sectional study of 190 high-risk patients with dizziness, HINTS examination outperforms ABCD2 risk scores [30]. The diagnostic yield for head CT ordered in the emergency department for acute dizziness is low (2.2%; 1.6% for emergent findings), but MRI changes the diagnosis up to 16% of the time, acutely in 8% of cases [2]. Earlier MRI studies in posterior fossa stroke showed a high false-negative rate on DWI when performed within the first 24 hours of symptom onset [44,45]. This has improved with better imaging techniques over time. MRI has a higher sensitivity for acute ischemic strokes than CT, although within the first 48 hours DWI still can be falsely negative in approximately 50% of small ischemic strokes in the posterior fossa [6,46]. Some have advocated for delayed MRI (3-7 days) if initial imaging was negative [1,29]. One single-center study of 36 patients with basilar artery occlusion found DWI MRI helps predict outcome in basilar artery occlusion patients treated with intra-arterial thrombolysis [47]. Variant 4: Adult. Chronic recurrent vertigo. Associated with unilateral hearing loss or tinnitus. Initial imaging. In contrast to an isolated episode of acute vertigo, chronic recurrent vertigo suggests an intermittently symptomatic long-standing condition. When associated unilateral hearing loss or tinnitus is present, the diagnosis of MD should be considered. MD is of unknown etiology. Patients have intermittent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus, and aural fullness. Previously a purely clinical diagnosis, imaging in MD has increased in the past decade. It is associated with endolymphatic hydrops (distension of labyrinthine structures). Imaging may also Dizziness and Ataxia