Dizziness and spatial disorientation in patients with transient global amnesia: clinical and vestibular correlates.

Abstract

Objective: To determine the prevalence and clinical significance of dizziness and spatial disorientation in patients with transient global amnesia (TGA), and to examine their relationships with vestibular function and imaging findings.

Methods: We retrospective analyzed 64 TGA episodes from 63 patients [46 (71.9%) women, mean age ± SD = 58.6 ± 9.4]. Vestibular and ocular motor function test [including vestibular-evoked myogenic potentials (VEMPs)], neuropsychological assessments, and brain imaging were evaluated. Logistic regression was used to identify factors associated with dizziness and spatial disorientation.

Results: Dizziness was reported in 30.6% (19/62 episodes), and spatial disorientation in 25.0% (16/64 episodes). In multivariable analysis, dizziness was independently associated with headache [odds ratio (OR) = 6.94; 95% confidence interval (CI) 1.91-25.25; p = 0.003] and Valsalva-like provoking events (OR = 4.19; 95% CI 1.14-15.38; p = 0.031). Abnormalities in ocular vestibular-evoked myogenic potentials (VEMPs) were significantly association with dizziness in univariate analysis (OR = 4.00; 95% CI 1.13-14.09; p = 0.031), but not in the multivariable analysis. In relation to spatial disorientation, abnormal cervical VEMPs showed a significant difference in chi-square test (p = 0.043), and a trend toward association in multivariable analysis (OR = 3.28; 95% CI 0.885-12.19; p = 0.076), suggesting otolithic vestibular dysfunction. There was a trend-level association between spatial disorientation and lower Korea-Montreal Cognitive Assessment scores (p = 0.066). Interestingly, patients in the spatial disorientation group showed better performance in visual memory immediate recall (p = 0.061), although this did not reach statistical significance. Hippocampal lesions were identified in 75.0% of TGA episodes, most commonly involving the hippocampal head. However, lesion laterality (left, right, or bilateral) was not associated with dizziness, spatial disorientation, or vestibular abnormalities.

Conclusion: Dizziness and spatial disorientation are common and clinically meaningful symptoms in TGA, likely reflecting transient dysfunction of specific vestibular pathways. These findings suggest broader network involvement in TGA in addition to the hippocampus, particularly implicating otolith-ocular and vestibulo-spinal pathways.