Ocular motor and vestibular dysfunction in central nervous system lymphoma.

BACKGROUND AND PURPOSE: Diagnosis of lymphoma involving the central nervous system (CNS) is challenging. This study aimed to explore the abnormal vestibular and ocular motor findings in CNS lymphoma. METHODS: A retrospective search of the medical records identified 30 patients with CNS lymphoma presenting ocular motor and vestibular abnormalities from four neurology clinics of university hospitals in South Korea (22 men, age range 14-81 years, mean 60.6 ± 15.2). The demographic and clinical features and the results of laboratory, radiological and pathological evaluation were analyzed. RESULTS: Patients presented with diplopia (13/30, 43%), vestibular symptoms (15/30, 50%) or both (2/30, 7%). In 15 patients with diplopia, abnormal ocular motor findings included ocular motor nerve palsy (n = 10, 67%), internuclear ophthalmoplegia (n = 2, 13%), external ophthalmoplegia (n = 2, 13%) and exophoria (n = 1, 7%). The vestibular abnormalities were isolated in 14 (82%) of 17 patients with vestibular symptoms and included combined unilateral peripheral and central vestibulopathy in three from lesions involving the vestibular nuclei. CNS lymphoma involved the brainstem (53%), cerebellum (33%), leptomeninges (30%), deep gray nuclei (23%) or cranial nerves (17%). Two patients showed the "double-panda" sign by involving the midbrain. CONCLUSIONS: This study expands the clinical and radiological spectra of CNS lymphoma. Neuro-ophthalmological and neuro-otological evaluation may guide the early diagnosis of CNS lymphoma.

Transient Vestibular Symptoms Preceding Posterior Circulation Stroke: A Prospective Multicenter Study.

BACKGROUND AND PURPOSE: The recognition of clinical features of transient vestibular symptoms (TVSs) preceding posterior circulation stroke (PCOS) would be informative to discriminate dizziness/vertigo due to vertebrobasilar transient ischemic attack from the acute transient vestibular syndrome. We sought to determine the prevalence and characteristics of TVSs preceding PCOS. METHODS: We performed a prospective multicenter observational study that had recruited 447 patients with PCOS from referral-based 4 university hospitals in Korea. We investigated the timing, pattern, frequency, duration, and accompanying neurological symptoms of TVSs during the 3 months preceding PCOS. RESULTS: The prevalence of TVSs preceding PCOS was 12% (55/447) during the previous 3 months. The TVSs preceding PCOS occurred within 1 week (33%), between 1 week and 1 month (16%), or between 1 and 3 months (51%). The TVSs were mostly dizziness/vertigo with (36%) or without (60%) imbalance, while the remaining 4% had an isolated imbalance. The dizziness/vertigo was spinning in 38% and was aggravated during head position in 45%. The duration of TVSs was mostly a few seconds (55%) or minutes (38%). Approximately 72% of the patients with PCOS had TVSs 1 to 5 times, while 16% had >10 times. Accompanying neurological symptoms, including headache, tinnitus, limb weakness, sensory change, dysarthria, visual field defect, and diplopia, were reported in 11%. CONCLUSIONS: Preceding TVSs can occur in 12% of PCOS during the previous 3 months. Isolated dizziness/vertigo of unknown cause needs to be considered as a vertebrobasilar transient ischemic attack symptom, especially in patients with vascular risk factors. The characteristics of isolated vestibular symptom in vertebrobasilar transient ischemic attacks is highly variable and atypical compared with other transient ischemic symptoms.

Episodic Vestibular Syndrome with Hyperventilation-Induced Downbeat Nystagmus.

Hyperventilation-induced downbeat nystagmus (HV-DBN) has been reported in cerebellar disorders and explained by a loss of the inhibitory cerebellar output via a metabolic effect on cerebellar Ca2+ channels. The aim of this study was to determine the clinical characteristics and underlying pathogenesis of episodic vestibular syndrome (EVS) with HV-DBN. Of 667 patients with EVS, we recruited 22 with HV-DBN and assessed their clinical characteristics, video-oculographic findings, and the results of molecular genetic analyses. The age at symptom onset was 47.5 ± 13.0 years (mean ± SD), and there was a female preponderance (n = 15, 68%). The duration of vertigo/dizziness attacks ranged from minutes to a few days, and 11 patients (50%) fulfilled the diagnostic criteria for vestibular migraine. HV-induced new-onset DBN in 8 patients, while the remaining 14 showed augmentation of spontaneous DBN by HV. The maximum slow-phase velocity of HV-DBN ranged from 2.2 to 11.9°/s, which showed a statistical difference with that of spontaneous DBN (median = 4.95, IQR = 3.68-6.55 vs. median = 1.25, IQR = 0.20-2.15, p < 0.001). HV-DBN was either purely downbeat (n = 11) or accompanied with small horizontal components (n = 11). Other neuro-otologic findings included perverted head-shaking nystagmus (n = 11), central positional nystagmus (n = 7), saccadic pursuit (n = 3), and horizontal gaze-evoked nystagmus (n = 1). Gene expression profiling with a bioinformatics analysis identified 43 upregulated and 49 downregulated differentially expressed genes (DEGs) in patients with EVS and HV-DBN and revealed that the downregulated DEGs were significantly enriched in terms related to the ribosome pathway. Our results suggest that the underlying cerebellar dysfunction would be responsible for paroxysmal attacks of vertigo in patients with EVS and HV-DBN.

Atypical clinical manifestations of Miller Fisher syndrome.

Miller Fisher syndrome (MFS) is characterized by a clinical triad of ophthalmoplegia, ataxia, and areflexia, and is closely associated with serum anti-GQ1b antibody. Although the clinical triad is the cardinal diagnostic clue, a variety of other symptoms and signs beyond the triad have been reported. To elucidate the frequency and characteristics of atypical clinical manifestations of MFS, we recruited 38 patients with MFS and evaluated the symptoms or signs beyond the classic triad. Eleven (29%) of 38 patients had atypical clinical manifestations of MFS such as headache (n = 6), delayed facial palsy (n = 3), divergence insufficiency (n = 2), and taste impairment (n = 2). Headache was localized to the periorbital (n = 3), temporal (n = 2), or whole (n = 1) area. Only one of them showed bilateral papilledema and an elevated opening pressure in cerebrospinal fluid analysis. Delayed facial palsy developed after the other signs have reached nadir (n = 1) or started to improve (n = 2), and did not follow a pattern of descending paralysis with other cranial neuropathies. Two patients showed divergence insufficiency without external ophthalmoplegia, and another two had taste impairment over the entire tongue without the other signs of facial and glossopharyngeal nerve involvements. Our study shows that approximately 30% of MFS patients can have atypical clinical manifestations beyond the classic triad. These results reflect the broad clinical spectrum of MFS, and might be associated with the presence of additional antiganglioside antibodies besides anti-GQ1b in patients with MFS.

Acute Transient Vestibular Syndrome: Prevalence of Stroke and Efficacy of Bedside Evaluation.

BACKGROUND AND PURPOSE: The aim of this study was to determine the prevalence of stroke and efficacy of bedside evaluation in diagnosing stroke in acute transient vestibular syndrome (ATVS). METHODS: We performed a prospective, single-center, observational study that had consecutively recruited 86 patients presenting with ATVS to the emergency department of Pusan National University Yangsan Hospital from January to December 2014. All patients received a constructed evaluation, including HINTS plus (head impulse, nystagmus patterns, test of skew, and finger rubbing) and brain magnetic resonance imagings. Patients without an obvious cause further received perfusion-weighted imaging. Multivariable logistic regression was used to determine clinical parameters to identify stroke in ATVS. RESULTS: The prevalence of stroke was 27% in ATVS. HINTS plus could not be applied to the majority of patients because of the resolution of the vestibular symptoms, and magnetic resonance imagings were falsely negative in 43% of confirmed strokes. Ten patients (12%) showed unilateral cerebellar hypoperfusion on perfusion-weighted imaging without an infarction on diffusion-weighted imaging, and 8 of them had a focal stenosis or hypoplasia of the corresponding vertebral artery. The higher risk of stroke in ATVS was found in association with craniocervical pain (odds ratio, 9.6; 95% confidence interval, 2.0-45.2) and focal neurological symptoms/signs (odds ratio, 15.2; 95% confidence interval, 2.5-93.8). CONCLUSIONS: Bedside examination and routine magnetic resonance imagings have a limitation in diagnosing strokes presenting with ATVS, and perfusion imaging may help to identify strokes in ATVS of unknown cause. Associated craniocervical pain and focal neurological symptoms/signs are the useful clues for strokes in ATVS.

Late-onset episodic ataxia associated with SLC1A3 mutation.

Episodic ataxia type 6 (EA6) is caused by mutations in SLC1A3 that encodes excitatory amino acid transporter 1 (EAAT1), a glial glutamate transporter. EAAT1 regulates the extent and durations of glutamate-mediated signal by the clearance of glutamate after synaptic release. In addition, EAAT1 also has an anion channel activity that prevents additional glutamate release. We identified a missense mutation in SLC1A3 in a family with EA. The proband exhibited typical EA2-like symptoms such as recurrent ataxia, slurred speech with a duration of several hours, interictal nystagmus and response to acetazolamide, but had late-onset age of sixth decade. Whole-exome sequencing detected a heterozygous c.1177G>A mutation in SLC1A3. This mutation predicted a substitution of isoleucine for a highly conserved valine residue in the seventh transmembrane domain of EAAT1. The mutation was not present in 100 controls, a large panel of in-house genome data and various mutation databases. Most functional prediction scores revealed to be deleterious. Same heterozygous mutation was identified in one clinically affected family member and two asymptomatic members. Our data expand the mutation spectrum of SLC1A3 and the clinical phenotype of EA6.

Isolated optic neuritis associated with Mycoplasma pneumoniae infection: report of two cases and literature review.

Mycoplasma pneumonia is a major pathogen of primary atypical pneumonia and has been known to cause various kinds of extrapulmonary manifestations involving almost all organs of the human body. Optic neuritis associated with M. pneumoniae infection has rarely been described and mostly, it combined other neurological complications including meningitis, meningoencephalitis, myelitis, and peripheral neuropathy. We report two patients who presented with isolated optic neuritis due to M. pneumoniae infection, and reviewed the literatures on five additional patients. All patients are child or young adults, and optic neuritis was unilateral (n = 3) or bilateral (n = 4). Remarkably, four patients did not have preceding history of respiratory M. pneumonia infection, and ocular pain or headache was accompanied in only three. Although initial visual acuities were severely reduced in most cases, visual outcome was excellent after systemic steroid and/or antibiotics treatment. M. pneumonia infection should be considered in the differential diagnosis of isolated optic neuritis, especially when occurring in a child or young adults, even though there was no preceding pneumonia, accompanying ocular pain, or headache. Various mechanisms including direct local inflammation, vascular occlusion, or indirect immune modulation due to M. pneumonia infection can lead to isolated neurological manifestations without pneumonia.

Clinical and Oculographic Analysis of Inferior Oblique Myokymia.

A 63-year-old man experienced transient vertical oscillopsia lasting several seconds for 2 months. Examination disclosed paroxysmal excyclotorsion of the right eye, spontaneously or triggered by adduction. Eye movements using 3D video-oculography showed intermittent, monocular phasic movements which consisted of excyclotorsion of the right eye mixed with a small amount of supraduction and abduction, and a tonic movement with excyclotorsion and slight elevation. Orbital and brain MRI was unremarkable. Administration of oxcarbazepine markedly decreased the severity and frequency of the episodes. The oculographic characteristics in our patient may indicate that inferior oblique myokymia may be attributed to aberrant, spontaneous discharges in the inferior oblique motor unit.

Neuroanatomical correlation of urinary retention in lateral medullary infarction.

We prospectively recruited 10 patients who presented with urinary retention as a neurological deficit that was attributable to lateral medullary infarction. Of these, 9 patients underwent a urodynamic study, which demonstrated detrusor underactivity of the bladder in 7 patients. Urinary retention developed mainly when the lesions involved the lateral tegmentum of the middle or caudal medulla. We concluded that interruption of the descending pathway from the pontine micturition center to the sacral spinal cord in the lateral medulla was responsible for the development of urinary retention.

Exercise-induced downbeat nystagmus in a Korean family with a nonsense mutation in CACNA1A.

Episodic ataxia type 2 (EA2) is characterized by recurrent attacks of vertigo and ataxia lasting hours triggered by emotional stress or exercise. Although interictal horizontal gaze-evoked nystagmus and rebound nystagmus are commonly observed in patients with EA2, the nystagmus has been rarely reported during the vertigo attack. To better describe exercise-induced nystagmus in EA2, four affected members from three generations of a Korean family with EA2 received full neurological and neuro-otological evaluations. Vertigo was provoked in the proband with running for 10 min to record eye movements during the vertigo attack. We performed a polymerase chain reaction-based direct sequence analysis of all coding regions of CACNA1A in all participants. The four affected members had a history of exertional vertigo, imbalance, childhood epilepsy, headache, and paresthesia. The provocation induced severe vertigo and imbalance lasting several hours, and oculography documented pure downbeat nystagmus during the attack. Genetic analyses identified a nonsense mutation in exon 23 which has been registered in dbSNP as a pathogenic allele (c.3832C>T, p.R1278X) in all the affected members. Ictal downbeat nystagmus in the studied family indicates cerebellar dysfunction during the vertigo attack in EA2. In patients with episodic vertigo and ataxia, the observation of exercise-induced nystagmus would provide a clue for EA2.

Rebound upbeat nystagmus after lateral gaze in episodic ataxia type 2.

Rebound nystagmus is a transient nystagmus that occurs on resuming the straight-ahead position after prolonged eccentric gaze. Even though rebound nystagmus is commonly associated with gaze-evoked nystagmus (GEN), development of rebound nystagmus in a different plane of gaze has not been described. We report a patient with episodic ataxia type 2 who showed transient upbeat nystagmus on resuming the straight-ahead position after sustained lateral gaze that had induced GEN and downbeat nystagmus. The rebound upbeat nystagmus may be ascribed to a shifting null in the vertical plane as a result of an adaptation to the downbeat nystagmus that developed during lateral gaze.

Vestibular hemispatial neglect: patterns and possible mechanism.

Recent reports have suggested that hemispatial neglect may be a vestibular disorder at the cortical level, based on the similarities of symptoms and neural correlates between the two phenomena. If this is the case, peripheral vestibulopathy may lead to hemispatial neglect. However, the etiology of hemispatial neglect in patients with unilateral peripheral vestibulopathy remains unclear. The aims of the present study were to investigate the following: (1) if unilateral peripheral vestibulopathy might cause hemispatial neglect, and if so, (2) whether hemispatial neglect in unilateral peripheral vestibulopathy might be induced by horizontal bias for eye position and body orientation or whether it is secondary to vestibular cortical dysfunction following unilateral peripheral vestibulopathy. Twenty-five consecutive patients with acute vestibular neuritis were recruited at the Dizziness Clinic of Pusan National University Hospital. All participants underwent neglect testing and measurements of horizontal bias for eye position and head and body orientation. Hemispatial neglect occurred in 32 % of patients with unilateral peripheral vestibulopathy. The frequency of contralesional neglect was equal to that of ipsilesional neglect. All patients with hemispatial neglect showed abnormal performance in bisection tasks. The incidence and severity of the horizontal bias of eye position and head and body orientation did not differ between patients with or without hemispatial neglect. Our study demonstrates that hemispatial neglect can develop after acute unilateral peripheral vestibulopathy. Hemispatial neglect after acute unilateral peripheral vestibulopathy may be attributed to damaged vestibular subnuclei, which receive afferents from both peripheral vestibular end organs and the vestibulocerebellum and project to the ipsilateral or contralateral thalamus and vestibular cortex.

Abnormal vestibular-evoked myogenic potentials as a risk factor for unpredicted falls in spinocerebellar ataxia: a preliminary study.

OBJECTIVE: This study aimed to correlate the symptoms and signs with the findings of laboratory vestibular function tests in patients with spinocerebellar ataxia (SCA). METHOD: We retrospectively recruited 26 patients with SCA (9 men, median age: 52, age range: 21-67). Assessments included Dizziness Handicap Inventory, EuroQoL Five-Dimension, symptom questionnaires manifesting during walking in daily life, the Scale for the Assessment and Rating of Ataxia (SARA), and vestibular function tests including 3D video-oculography, video head impulse test, subjective visual vertical, and cervical and ocular vestibular evoked myogenic potentials (VEMP). RESULTS: Cross-analyses revealed that the patients with VEMP abnormalities showed higher SARA (p = 0.014) and prevalence of unpredictable falls (p = 0.046). The patients with SCA1 more frequently had unpredictable falls (75%, p = 0.038) and VEMP abnormalities (88%, p = 0.001) compared to SCA2 (29% falls, 17% VEMP abnormalities) and SCA6 (no falls or VEMP abnormalities). CONCLUSION: Abnormal VEMPs are strongly associated with unpredicted falls in patients with SCA, particularly in those with SCA1. Impaired processing of otolithic information may contribute to falls in SCAs, and VEMP may help identifying the patients with a risk for unpredicted falls and preventing fall-related injuries in SCA. Limited number of patients with lower SARA scores warrant further confirmatory studies.

Expanding Clinical Spectrum of Anti-GQ1b Antibody Syndrome: A Review.

Importance: The discovery of the anti-GQ1b antibody has expanded the nosology of classic Miller Fisher syndrome to include Bickerstaff brainstem encephalitis, Guillain-Barré syndrome with ophthalmoplegia, and acute ophthalmoplegia without ataxia, which have been brought under the umbrella term anti-GQ1b antibody syndrome. It seems timely to define the phenotypes of anti-GQ1b antibody syndrome for the proper diagnosis of this syndrome with diverse clinical presentations. This review summarizes these syndromes and introduces recently identified subtypes. Observations: Although ophthalmoplegia is a hallmark of anti-GQ1b antibody syndrome, recent studies have identified this antibody in patients with acute vestibular syndrome, optic neuropathy with disc swelling, and acute sensory ataxic neuropathy of atypical presentation. Ophthalmoplegia associated with anti-GQ1b antibody positivity is complete in more than half of the patients but may be monocular or comitant. The prognosis is mostly favorable; however, approximately 14% of patients experience relapse. Conclusions and Relevance: Anti-GQ1b antibody syndrome may present diverse neurological manifestations, including ophthalmoplegia, ataxia, areflexia, central or peripheral vestibulopathy, and optic neuropathy. Understanding the wide clinical spectrum may aid in the differentiation and management of immune-mediated neuropathies with multiple presentations.

Clinical Significance of Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio in Acute Unilateral Vestibulopathy.

BACKGROUND AND PURPOSE: The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been identified as useful biomarkers for assessing the inflammatory response and for predicting the prognosis of various diseases. This study aimed to determine the clinical significance and effects on prognostic prediction of NLR and PLR in acute unilateral vestibulopathy (AUV). METHODS: We retrospectively recruited 128 patients who were diagnosed with AUV from July 2016 to April 2021, and compared NLR and PLR values between these patients with AUV and age- and sex-matched healthy subjects. We also analyzed the correlations of various clinical parameters with NLR and PLR. RESULTS: NLR and PLR in the AUV group were 3.41±2.80 (mean±standard deviation) and 128.86±67.06, respectively, with only NLR being significantly higher than that in the control group (1.55±0.60, p<0.001). The gain asymmetry of the horizontal vestibulo-ocular reflex (VOR) was slightly larger in patients with high NLR (n=52) than in those with normal NLR (n=76) (41.9%±20.2% vs. 33.6%±17.4%, p=0.048). However, the hospitalization period, preceding infection, canal paresis, and absolute horizontal VOR gain did not differ between patients with high and normal NLR and PLR values. The correlation analyses also revealed that none of the clinical parameters were significantly correlated with NLR or PLR. At 3-month follow-up examinations, NLR and PLR did not differ significantly between patients with and without function recovery of the horizontal VOR. CONCLUSIONS: This study found a high NLR in AUV, suggesting an acute inflammatory status in the vestibular organ. However, the usefulness of NLR and PLR as prognostic markers remains unclear.

Triggered saccadic oscillations: case series and review of the literature.

Saccadic oscillations (SOs) mostly occur spontaneously, but can be occasionally triggered by various stimuli. To determine clinical characteristics and underlying mechanisms of triggered SOs, we analyzed the clinical features and quantitative eye-movement recordings of six new patients and 10 patients in the literature who exhibited with triggered SOs. Eleven of the 16 patients (69%) had a lesion involving cerebellum and/or brainstem such as cerebellar degeneration, cerebellitis, or cerebellar infarction. The other causes were vestibular migraine (n = 2), multiple sclerosis (n = 1), Krabbe disease (n = 1), and idiopathic (n = 1). Vestibular stimulation was the most common trigger (n = 11, 69%), followed by removal of visual fixation (n = 4, 25%), hyperventilation (n = 1), light (n = 1), and blink (n = 1). The types of triggered SOs were varied which included ocular flutter (n = 13), opsoclonus (n = 3), vertical SOs (n = 2), and macrosaccadic oscillations (n = 1). Three patients exhibited downbeat nystagmus either before (n = 1) or after (n = 2) the onset of SOs. The frequency of triggered SOs ranged from 4 to 15 Hz, and oscillations with smaller amplitudes had higher frequencies and smaller peak velocities. SOs can be triggered by the modulation of unstable saccadic neural networks through vestibular and visual inputs in lesions of the brainstem and cerebellum.

Clinical characteristics of persistent postural-perceptual dizziness and its visual subtype in Korean patients: A multicenter cross-sectional study.

OBJECTIVES: Persistent postural-perceptual dizziness (PPPD) is a chronic functional vestibular disorder for which the Bárány Society has established diagnostic criteria. This nationwide multicenter study aims to investigate the clinical features of individuals with definite PPPD and clinical variant PPPD who do not fully meet the diagnostic criteria, with a particular focus on visual exaggeration. METHODS: Between September 2020 and September 2021, a total of 76 individuals with definite PPPD and 109 individuals with clinical variant PPPD who did not meet all three exacerbating factors outlined in Criterion B were recruited from 18 medical centers in South Korea. The study gathered information on demographic factors, clinical manifestations, balance scales, and personality assessments. RESULTS: Comparative analysis between groups with definite PPPD and clinical variant with visual exacerbation revealed no significant differences in sociodemographic characteristics, clinical course, dizziness impact, and specific precipitants. Only disease duration was significantly longer in definite PPPD compared with variant with visual exacerbation. However, the variant without visual exacerbation displayed significantly reduced rates of panic disorder, diminished space-motion discomfort, lesser impact of dizziness, and decreased prevalence of depression when compared with the definitive PPPD. CONCLUSION: This is the first comprehensive nationwide study examining clinical features of both definite PPPD patients and its clinical variants, considering visual exacerbating factors. Differences in dizziness and personality traits emerged between definite PPPD and its potential variant without visual issues. Our results highlight the possibility of a distinct clinical variant of PPPD influenced by visual dependency.