The bucket test differentiates patients with MRI confirmed brainstem/cerebellar lesions from patients having migraine and dizziness alone

Background

Amongst the most challenging diagnostic dilemmas managing patients with vestibular symptoms (i.e. vertigo, nausea, imbalance) is differentiating dangerous central vestibular disorders from benign causes. Migraine has long been recognized as one of the most common causes of vestibular symptoms, but the clinical hallmarks of vestibular migraine are notoriously inconsistent and thus the diagnosis is difficult to confirm. Here we conducted a prospective study investigating the sensitivity and specificity of combining standard vestibular and neurological examinations to determine how well central vestibular disorders (CVD) were distinguishable from vestibular migraine (VM).

Method

Twenty-seven symptomatic patients diagnosed with CVD and 36 symptomatic patients with VM underwent brain imaging and clinical assessments including; 1) SVV bucket test, 2) ABCD², 3) headache/vertigo history, 4) presence of focal neurological signs, 5) nystagmus, and 6) clinical head impulse testing.

Results

Mean absolute SVV deviations measured by bucket testing in CVD and VM were 4.8 ± 4.1° and 0.7 ± 1.0°, respectively. The abnormal rate of SVV deviations (> 2.3°) in CVD was significantly higher than VM (p < 0.001). Using the bucket test alone to differentiate CVD from VM, sensitivity was 74.1%, specificity 91.7%, positive likelihood ratio (LR+) 8.9, and negative likelihood ratio (LR-) 0.3. However, when we combined the SVV results with the clinical exam assessing gaze stability (nystagmus) with an abnormal focal neurological exam, the sensitivity (92.6%) and specificity (88.9%) were optimized (LR+ (8.3), LR- (0.08)).

Conclusion

The SVV bucket test is a useful clinical test to distinguish CVD from VM, particularly when interpreted along with the results of a focal neurological exam and clinical exam for nystagmus.

Electronic supplementary material

The online version of this article (10.1186/s12883-019-1442-z) contains supplementary material, which is available to authorized users.

Video head impulse testing: Pitfalls in neurological patients

The video head impulse test (vHIT) assesses the vestibulo-ocular reflex (VOR) during a rapid high-velocity low amplitude (10°-20°) head rotation. Patients with peripheral vestibulopathy have a reduced VOR gain with corrective catch-up saccades during the head turn. There are several pitfalls, mainly technical, which may interfere with interpretation of vHIT data. In addition, intrusive eye movement disorders such as spontaneous nystagmus that affect normal eye position and tracking can affect the vHIT results. To date there has been little study of neurological saccadic eye movements that may interfere with the interpretation of vHIT data. Here, in ten patients with a range of central neurological disorders, we describe oculomotor abnormalities on vHIT in the presence of normal range VOR gain values, recorded at a tertiary vestibular neurology service.

The diagnosis of central vestibular disorders based on the complementary examination of the vestibulospinal reflex

OBJECTIVES

Stance and gait unsteadiness along with vertigo contribute to a central vestibular disorder. For objective analysis ultrasound-computer-craniocorpography (US-COMP-CCG) can be used. Aim of the study was to characterize the unsteadiness in central vestibular disorders and discuss the possible diagnostic usage of US-COMP-CCG.

METHODS AND RESULTS

Hundred-and-ninety patients (70 male and 120 female, mean age ± SD, 58.94 ± 15.27) suffering from central vestibular disorder and 230 healthy control patients (78 male and 152 female, mean age ± SD, 50.94 ± 15.27) were enrolled. Stance and gait analysis was according to vestibulospinal tests of US-COMPCCG. IBM SPSS V24 software was used for statistical analysis. Mann-WhitneyU test and Chi-square test were used, along with sensitivity and specificity categorization. The significance level was p < 0.05. According to schematic and statistical analysis instability and postural sway were increased in the vertigo population and statistically significant difference was shown. Upon categorical analysis significant correlation was detected [standing test: longitudinal sway (p < 0.00001), lateral sway (p < 0.00001), forehead covering area parameters (p = 0.0001); stepping test: longitudinal deviation (p = 0.05), lateral sway (p = 0.011) parameters].

CONCLUSIONS

Clinicians should consider that postural instability is prominently present in this population and might be of a diagnostic importance.

Lateral Medullary Syndrome Following Injury of Lateral Vestibulospinal Tract: Diffusion Tensor Imaging Study

BACKGROUND

Unilateral lesions of vestibular nucleus can cause lateral medullary syndrome. Little is known about injury of medial and lateral vestibulospinal tract (VST) after dorsolateral medullary infarct. We investigated injury of the lateral VST in patients with typical central vestibular disorder using diffusion tensor tractography (DTT).

METHODS

Seven patients with lateral medullary syndrome and ten control subjects were recruited. For the medial VST, we determined seed region of interest (ROI) as medial vestibular nuclei of pons and target ROI on posteromedial medulla. For the lateral VST, the seed ROI was placed on lateral vestibular nuclei of pons, and the target ROI on posterolateral medulla. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume were measured.

RESULT

Reconstructed lateral VST on both sides had significantly lower FA values in patients than controls (p<0.05). Tract volume of lateral VST in affected side was significantly lower than unaffected side and control group (p<0.05). However, no DTI parameters of the medial VST differed between patients and controls (p>0.05).

CONCLUSION

Injury of the lateral VST was demonstrated in patients with lateral vestibular syndrome following dorsolateral medullary infarct. Analysis of the lateral VST using DTT would be helpful in evaluation of patients with lateral medullary syndrome.