Clinical evaluation of acute phase nystagmus associated with cerebellar lesions

Systematic review and meta-analysis of the diagnostic accuracy of spontaneous nystagmus patterns in acute vestibular syndrome

Objectives

For the assessment of patients presenting with acute prolonged vertigo meeting diagnostic criteria for acute vestibular syndrome (AVS), bedside oculomotor examinations are essential to distinguish peripheral from central causes. Here we assessed patterns of spontaneous nystagmus (SN) observed in AVS and its diagnostic accuracy at the bedside.

Methods

MEDLINE and Embase were searched for studies (1980-2022) reporting on the bedside diagnostic accuracy of SN-patterns in AVS patients. Two independent reviewers determined inclusion. We identified 4,186 unique citations, examined 219 full manuscripts, and analyzed 39 studies. Studies were rated on risk of bias (QUADAS-2). Diagnostic data were extracted and SN beating-direction patterns were correlated with lesion locations and lateralization.

Results

Included studies reported on 1,599 patients, with ischemic strokes (n = 747) and acute unilateral vestibulopathy (n = 743) being most frequent. While a horizontal or horizontal-torsional SN was significantly more often found in peripheral AVS (pAVS) than in central AVS (cAVS) patients (672/709 [94.8%] vs. 294/677 [43.4%], p < 0.001), torsional and/or vertical SN-patterns were more prevalent in cAVS than in pAVS (15.1 vs. 2.6%, p < 0.001). For an (isolated) vertical/vertical-torsional SN or an isolated torsional SN specificity (97.7% [95% CI = 95.1-100.0%]) for a central origin etiology was high, whereas sensitivity (19.1% [10.5-27.7%]) was low. Absence of any horizontal SN was more frequently observed in cAVS than in pAVS (55.2 vs. 7.0%, p < 0.001). Ipsilesional and contralesional beating directions of horizontal SN in cAVS were found at similar frequency (28.0 vs. 21.7%, p = 0.052), whereas for pAVS a contralesional SN was significantly more frequent (95.2 vs. 2.5%, p < 0.001). For PICA strokes presenting with horizontal SN, beating direction was ipsilesional more often than contralesional (23.9 vs. 6.4%, p = 0.006), while the opposite was observed for AICA strokes (2.2 vs. 63.0%, p < 0.001).

Conclusions

(Isolated) vertical and/or torsional SN is found in a minority (15.1%) of cAVS patients only. When present, it is highly predictive for a central cause. A combined torsional-downbeating SN-pattern may be observed in pAVS also in cases with isolated lesions of the inferior branch of the vestibular nerve. Furthermore, in cAVS patients the SN beating direction itself does not allow a prediction on the lesion side.

Capturing nystagmus in the emergency room: posterior circulation stroke versus acute vestibular neuritis

OBJECTIVES

To compare acute nystagmus characteristics of posterior circulation stroke (PCS) and acute vestibular neuritis (AVN) in the emergency room (ER) within 24 h of presentation.

METHODS

ER-based video-nystagmography (VNG) was conducted, recording ictal nystagmus in 101 patients with PCS (on imaging) and 104 patients with AVN, diagnosed on accepted clinical and vestibular test criteria.

RESULTS

Patients with stroke in the brainstem (38/101, affecting midbrain (n = 7), pons (n = 19), and medulla (n = 12)), cerebellum (31/101), both (15/101) or other locations (17/101) were recruited. Common PCS territories included posterior-inferior-cerebellar-artery (41/101), pontine perforators (18/101), multiple-territories (17/101) and anterior-inferior-cerebellar-artery (7/101). In PCS, 44/101 patients had no spontaneous nystagmus. Remaining PCS patients had primary position horizontal (44/101), vertical (8/101) and torsional (5/101) nystagmus. Horizontal nystagmus was 50% ipsiversive and 50% contraversive in lateralised PCS. Most PCS patients with horizontal nystagmus (28/44) had unidirectional "peripheral-appearing" nystagmus. 32/101 of PCS patients had gaze-evoked nystagmus. AVN affected the superior, inferior or both divisions of the vestibular nerve in 55/104, 4/104 and 45/104. Most (102/104) had primary position horizontal nystagmus; none had gaze-evoked nystagmus. Two inferior VN patients had contraversive torsional-downbeat nystagmus. Horizontal nystagmus with SPV ≥ 5.8 °/s separated AVN from PCS with sensitivity and specificity of 91.2% and 83.0%. Absent nystagmus, gaze-evoked nystagmus, and vertical-torsional nystagmus were highly specific for PCS (100%, 100% and 98.1%).

CONCLUSION

Nystagmus is often absent in PCS and always present in AVN. Unidirectional 'peripheral-appearing' horizontal nystagmus can be seen in PCS. ER-based VNG nystagmus assessment could provide useful diagnostic information when separating PCS from AVN.

[Vertical nystagmus]

The review article provides a definition and classification of different nystagmus types, a comparative description of the central and peripheral vestibular nystagmus. The pathogenetic patterns of up-beating and down-beating nystagmus are accurately described. The features of nystagmus formation in various diseases are discussed, such as Wernicke encephalopathy, Arnold-Chiari anomaly, spinocerebellar ataxia and vestibular migraine. The authors provide their own data on oculomotor disorders in 100 patients with vestibular migraine and migraine with a brain stem aura. This article considers approaches to treatment: surgical and conservative. In conclusion, was noted the possibility of differentiating the central and peripheral vestibular nystagmus by means of clinical study. As well, the differences between vertical nystagmus associated with organic lesions of the brain stem or cerebellum and transient nystagmus with vestibular migraine are highlighted. The authors note the need for in-depth studies of nystagmus in vestibular migraine patients and methods of dealing with it.

New Insights Into Vertigo Attack Frequency as a Predictor of Ischemic Stroke

Background: Recurrent attacks of vertigo account for 2.6 million emergency department visits per year in the USA, of which more than 4% are attributable to ischemic infarction. However, few studies have investigated the frequency of attacks of vertigo before an ischemic stroke.

Methods: We conducted this retrospective analysis and manually screened the medical records of 231 patients who experienced recurrent attacks of vertigo prior to an ischemic stroke. Patients were divided into four different groups based on the frequency of vertigo attacks as well as the region of ischemic infarction. Those with ≤2 attacks of vertigo preceding the ischemic stroke were defined as the low-frequency group. Those with ≥3 attacks were defined as the high-frequency group. Clinical parameters, including vascular risk factors, average National Institutes of Health Stroke Scale (NIHSS) score, and infarction volume, were compared between the groups.

Results: On analysis, we found that patients with posterior infarction in the high-frequency group exhibited a higher prevalence of vertebral artery stenosis. However, the incidence of diabetes mellitus (DM) was higher in the low-frequency group. In addition, patients with posterior infarction in the low-frequency group were more active in seeking medical intervention after an attack of vertigo. Notably, the brain stem, especially the lateral medullary region, had a higher probability of being involved in posterior infarction in the high-frequency group. However, the cerebellum was more commonly involved in posterior infarction in the low-frequency group.

Conclusions: Our findings indicate that the clinical parameters, including arterial stenosis, DM, and magnetic resonance imaging (MRI) findings, differed between the low- and high-frequency groups. We also found that patients in the low-frequency group were more willing to seek medical intervention after the attacks of vertigo. These findings could be valuable for clinicians to focus on specific examination of the patients according to the frequency of vertigo attacks.

An Interesting Unknown Combined Pathology in a Patient with Acute Balance Problem

A 54-year-old woman with acute-onset nausea and vomiting presented to outpatient clinic. She had headache for 3 weeks. She had difficulty during tandem gait and was falling to the right. Otherwise, her neurological examination was normal. She had normal hearing. VNG analysis revealed spontaneous nystagmus beating to the left with optical fixation. However, she had horizontal and slightly down-beating gaze-evoked nystagmus at primary gaze position. Temporal bone CT and MRI showed widespread encephalitis of the right side of the brain and isolated destruction of the right superior semicircular canal. The patient was treated with high-dose combined antibiotics. She had remarkable recovery within 3 weeks.

Current diagnostic procedures for diagnosing vertigo and dizziness

Vertigo is a multisensory syndrome that otolaryngologists are confronted with every day. With regard to the complex functions of the sense of orientation, vertigo is considered today as a disorder of the sense of direction, a disturbed spatial perception of the body. Beside the frequent classical syndromes for which vertigo is the leading symptom (e.g. positional vertigo, vestibular neuritis, Menière’s disease), vertigo may occur as main or accompanying symptom of a multitude of ENT-related diseases involving the inner ear. It also concerns for example acute and chronic viral or bacterial infections of the ear with serous or bacterial labyrinthitis, disorders due to injury (e.g. barotrauma, fracture of the oto-base, contusion of the labyrinth), chronic-inflammatory bone processes as well as inner ear affections in the perioperative course. In the last years, diagnostics of vertigo have experienced a paradigm shift due to new diagnostic possibilities. In the diagnostics of emergency cases, peripheral and central disorders of vertigo (acute vestibular syndrome) may be differentiated with simple algorithms. The introduction of modern vestibular test procedures (video head impulse test, vestibular evoked myogenic potentials) in the clinical practice led to new diagnostic options that for the first time allow a complex objective assessment of all components of the vestibular organ with relatively low effort. Combined with established methods, a frequency-specific assessment of the function of vestibular reflexes is possible. New classifications allow a clinically better differentiation of vertigo syndromes. Modern radiological procedures such as for example intratympanic gadolinium application for Menière’s disease with visualization of an endolymphatic hydrops also influence current medical standards. Recent methodical developments significantly contributed to the possibilities that nowadays vertigo can be better and more quickly clarified in particular in otolaryngology.