The associations of adherence to the Mediterranean diet with chronic dizziness and imbalance in community-dwelling adults: KNHANES 2019-2021.

BACKGROUND: Dizziness and vertigo rank among the top 10 reasons for emergency and clinical referrals to neurologists. Chronic dizziness and imbalance not only reduce quality of life, but also increase mortality. While the Mediterranean diet has long been considered beneficial for human and planetary health, its effects on chronic dizziness or imbalance are understudied. We investigated the associations of adherence to the Mediterranean diet with chronic dizziness and imbalance. METHODS: This study used data from the Korea National Health and Nutrition Examination Survey 2019-2021 and included 4,183 adults aged 40 years and older with complete information from diet, dizziness, and neurotology questionnaires. The alternate Mediterranean diet score (aMed) for nine food groups was calculated from 24-hour dietary recall data. Based on questionnaire responses, chronic dizziness was categorized as either isolated or chronic dizziness with imbalance, characterized by a cluster of difficulties maintaining a standing position, walking, or falling. RESULTS: In a multivariable-adjusted model, the prevalence of chronic imbalance was lower in the top aMed tertile than in the bottom tertile (OR 0.37; 95% CI, 0.18-0.74; p-trend = 0.01). Among the individual aMed components, the intake of whole grains and nuts exhibited an inverse relationship with chronic imbalance (OR 0.50; 95% CI, 0.27-0.93 for whole grains; OR 0.55; 95% CI, 0.31-1.01 for nuts). The aMed score was not associated with isolated chronic dizziness. CONCLUSIONS: Greater adherence to the Mediterranean diet may reduce chronic imbalance, particularly with an adequate intake of whole grains and nuts.

Ocular Motor Findings Aid in Differentiation of Spinocerebellar Ataxia Type 17 from Huntington's Disease.

Differentiation of spinocerebellar ataxia type 17 (SCA17) from Huntington's disease (HD) is often challenging since they share the clinical features of chorea, parkinsonism, and dystonia. The ocular motor findings remain to be elucidated in SCA17, and may help differentiating SCA17 from HD. We retrospectively compared the ocular motor findings of 11 patients with SCA17 with those of 10 patients with HD. In SCA17, abnormal ocular motor findings included impaired smooth pursuit (9/11, 82%), dysmetric saccades (9/11, 82%), central positional nystagmus (CPN, 7/11, 64%), abnormal head-impulse tests (4/11, 36%), and horizontal gaze-evoked nystagmus (GEN, 3/11, 27%). Among these, CPN was more frequently observed in SCA17 than in HD (7/11 (64%) vs. 0/10 (0%), p = 0.004) while saccadic slowing was more frequently observed in HD than in SCA17 (8/10 (80%) vs. 2/11 (18%), p = 0.009). Of six patients with follow-up evaluation, five later developed bilateral saccadic hypermetria (n = 4), GEN (n = 1), CPN (n = 1), bilaterally abnormal smooth pursuit (n = 1), and hyperactive head-impulse responses (n = 1) along with a clinical decline. Ocular motor abnormalities can be utilized as a diagnostic marker for differentiation of SCA17 from HD as well as a surrogate marker for clinical decline in SCA17.

Comparison of high-flow nasal cannula oxygen therapy and conventional reserve-bag oxygen therapy in carbon monoxide intoxication: A pilot study.

BACKGROUND: High-flow nasal cannula oxygen (HFNC) creates a positive pressure effect through high-flow rates compared to conventional oxygen therapy. The purpose of this human pilot study is to compare the effects of HFNC and conventional oxygen therapy on the rate of carbon monoxide (CO) clearance from the blood in patients with mild to moderate CO poisoning. METHODS: CO-poisoned Patients randomly received 100% oxygen from a rebreathing reserve mask (NBO2, flow of 15 L/min) or HFNC (flow of 60 L/min). The fraction of COHb value (fCOHb) was measured in 30-min intervals until it fell to under 10%. We determined the Half-life time of fCOHb (fCOHb t1/2). RESULTS: A total of 22 patients had fCOHb levels ≥ 10% at the time of ED arrival, with 9 of them having fCOHb level ranging between 25% and 50%. There was no significant difference in the fCOHbt1/2 between the HFNC group and NBO2 group. However, the mean fCOHbt1/2 in the HFNC group (48.5 ±â€¯12.4 min) has a smaller standard deviation than that in the NBO2 group (99.3 ±â€¯93.38 min). There were significant between-group differences in the mean COHbt1/2 among the patients with fCOHb levels less than 25% (HFNC 43.6 ±â€¯10.6 vs. NBO2 134.2 ±â€¯111.3). CONCLUSIONS: In this pilot randomized controlled trial study, HFNC therapy did not reduce fCOHbt1/2 compared to NBO2 therapy but could be beneficial in maintaining a constant fCOHbt1/2 as well as in reducing fCOHbt1/2 in mild CO poisoning patients compared to conventional NBO2 therapy. However, further studies with a larger number of patients are needed to establish HFNC therapy as an alternative therapy for CO poisoning patients.

Impaired Calcium Metabolism in Benign Paroxysmal Positional Vertigo: A Topical Review.

BACKGROUND AND PURPOSE: Although acute attacks of benign paroxysmal positional vertigo (BPPV) may be treated with canalith repositioning maneuvers, there have been no well-designed prospective trials to prevent this highly prevalent and recurrent disorder. This topical review explores the evidence related to the association between deficient calcium metabolism and BPPV. We also describe the development of therapeutic options to prevent recurrences of BPPV and introduce results from a recent randomized controlled trial on the effect of vitamin D and calcium supplementation in preventing BPPV recurrences. SUMMARY OF KEY POINTS: The literature describes 3 lines of evidence on association of impaired calcium metabolism and development of BPPV: (1) decreased bone mineral density was more frequently observed in persons with BPPV than in healthy controls; (2) estrogen plays a vital role in maintenance of otoconia, and estrogen deficiency appears to precipitate degeneration of otoconia and development of BPPV; and (3) lower serum vitamin D level is associated with development of BPPV, and supplementation of vitamin D and calcium carbonate may reduce further attacks of BPPV in persons with BPPV and subnormal serum vitamin D level. RECOMMENDATIONS FOR CLINICAL PRACTICE: Restoration of impaired calcium metabolism with supplementation of vitamin D or estrogen should be considered in the treatment of individuals with frequent recurrences of BPPV. Future randomized controlled trials are mandatory to validate these supplementation therapies in individuals with recurrent BPPV.

Early diffusion-weighted imaging and outcome prediction of comatose survivors after suicidal hanging.

PURPOSE: Early outcome prediction after suicidal hanging is challenging in comatose survivors. We analysed the early patterns of brain diffusion-weighted magnetic resonance imaging (DWI) abnormalities in comatose survivors after suicidal hanging. METHODS: After suicidal hanging, 18 comatose survivors were prospectively evaluated from January 2013 to December 2016. DWI was performed within 3 h after hanging in comatose survivors. We evaluated Utstein style variables and analysed abnormal spatial profile of signal intensity on DWI, brain apparent diffusion coefficient (ADC) values, and qualitative DWI scores to predict neurological outcomes. RESULTS: All hanging associated cardiac arrest (CA) patients demonstrated bad neurological outcomes; 80% of non-CA comatose patients experienced good neurological outcomes. In hanging survivors with CA, cortical grey matter structures and deep grey nuclei exhibited profound ADC reductions and high DWI scores within 3 h after hanging, which was associated with diffuse anoxic brain damage with poor cerebral performance categories scores. CA comatose survivors had significantly lower ADC values and higher DWI scores compared to non-CA comatose survivors in the cortex and deep grey nuclei. CONCLUSION: Although the presence of CA is the most important clinical prognosticator in hanging-associated comatose survivors, HSI abnormalities and low ADC values in the cortex and deep grey nuclei on DWI performed within 3 h after hanging are well-correlated with unfavourable outcomes regardless of therapeutic hypothermia. Therefore, early DWI may increase the sensitivity of poor outcome prediction and may be an effective combinatorial screening method when available prognostic variables are not reliable or conclusive.

Moderate brain hypothermia started before resuscitation improves survival and neurobehavioral outcomes after CA/CPR in mice.

AIM OF THE STUDY: No definitive experimental or clinical evidence exists whether brain hypothermia before, rather than during or after, resuscitation can reduce hypoxic-ischemic brain injury following cardiac arrest/cardiopulmonary resuscitation (CA/CPR) and improve outcomes. We examined the effects of moderate brain hypothermia before resuscitation on survival and histopathological and neurobehavioral outcomes in a mouse model. METHODS: Adult C57BL/6 male mice (age: 8-12 weeks) were subjected to 8-min CA followed by CPR. The animals were randomly divided into sham, normothermia (NT; brain temperature 37.5 °C), and extracranial hypothermia (HT; brain temperature 28-32 °C) groups. The hippocampal CA1 was assessed 7 day after resuscitation by histochemical staining. Neurobehavioral outcomes were evaluated by the Barnes maze (BMT), openfield (OFT), rotarod, and light/dark (LDT) tests. Cleaved caspase-3 and heat shock protein 60 (HSP70) levels were investigated by western blotting. RESULTS: The HT group exhibited higher survival and lower CA1 neuronal injury than did the NT group. HT mice showed improved spatial memory in the BMT compared with NT mice. NT mice travelled a shorter distance in the OFT and tended to spend more time in the light compartment in the LDT than did sham and HT mice. The levels of cleaved caspase-3 and HSP70 were non-significantly higher in the NT than in the sham and HT groups. CONCLUSIONS: Moderate brain hypothermia before resuscitation improved survival and reduced histological neuronal injury, spatial memory impairment, and anxiety-like behaviours after CA/CPR in mice.

Acute intractable headache and oculomotor nerve palsy associated with nicorandil: A case report.

Acute non-traumatic headaches with neurological deficits alarm emergency department (ED) physicians. Typically, a sudden headache with oculomotor nerve palsy involving a pupil indicates the possibility of a subarachnoid hemorrhage (SAH) due to an aneurysm originating from the posterior communicating artery. For the ED physician, thinking beyond the possibility of an SAH can be crucial. Here, we report on a 59-year-old woman who presented to the ED with an intractable headache and right ptosis. She had previously received nicorandil for paroxysmal atrial fibrillation in the cardiology clinic. Her vital signs were stable upon ED arrival. Neurological examination revealed a mild anisocoria with a sluggish response to light stimuli in the right eye. Adduction, supraduction, and infraduction were also limited in the right eye. Nuchal rigidity was not apparent. An urgent brain magnetic resonance image (MRI) with angiography was requested to assess for possible SAH, but revealed no aneurysm. Cerebrospinal fluid analysis was also unremarkable. The patient's headache and oculomotor nerve palsy improved completely after discontinuation of nicorandil for 3 days. To the best of our knowledge, this is the first case report on side effects of nicorandil presenting as a severe headache with reversible oculomotor nerve palsy involving a pupil, symptoms which mimicked a possible SAH due to aneurysm.

Vertical Head Thrusting in Acquired Supranuclear Vertical Ophthalmoplegia.

Patients with congenital ocular motor apraxia (OMA) typically show head thrusts while attempting to shift gaze. In congenital OMA, this compensatory head motion mostly occurs in the horizontal plane. Two patients with acquired palsy of voluntary vertical gaze and continuous upward gaze deviation, one from aortic surgery and the other from multiple infarctions involving the mesodiencephalic junction, showed intermittent downward head thrusting to redirect the eyes straight ahead or downward. The head thrusting behavior improved markedly after surgical correction of the upward gaze deviation in one patient. Vertical head thrusting may be a characteristic sign of acquired vertical gaze palsy when combined with vertical gaze deviation.

Central Trochlear Palsy: Report of Two Patients With Ipsilesional Palsy and Review of the Literature.

BACKGROUND: The trochlear (fourth) nerve is the only cranial nerve that decussates before emerging from the posterior aspect of the brainstem. Lesions involving the trochlear nucleus or fascicles mostly give rise to contralesional superior oblique palsy (SOP). METHODS: We report 2 patients with SOP on the side of intraaxial lesions with a literature review on central trochlear palsy. RESULTS: The lesions are more commonly located posterior to the cerebral aqueduct in patients with ipsilesional SOP than in those with contralesional SOP. CONCLUSIONS: Intraaxial lesions may cause ipsilesional or contralesional SOP depending on the lesion location along the course of trochlear fascicle in the brainstem.

Anti-aquaporin-4 antibody-positive dorsal midbrain syndrome.

Neuromyelitis optica spectrum disorders (NMOSD) can cause various ocular motor disorders in addition to optic neuritis. Ocular motor findings associated with NMOSD include spontaneous vertical and gaze-evoked nystagmus, wall-eyed bilateral internuclear ophthalmoplegia, and trochlear nerve palsy. The association between dorsal midbrain syndrome and anti-aquaporin-4 antibody seropositivity has not been reported. Here, we report a patient displaying typical dorsal midbrain syndrome and anti-aquaporin-4 antibody seropositivity.

Muscle mass and chronic dizziness: a cross-sectional study of a Korean population.

BACKGROUND AND OBJECTIVES: Weight gain is associated with imbalance in older people. In contrast, overweightness or mild obesity is less common in patients with chronic dizziness. This paradox may be, at least in part, related to differences in the body composition indices adopted in the previous studies. This study aimed to determine any association between the predicted body composition and chronic dizziness or imbalance of unknown causes. METHODS: We measured the lean body mass, body fat mass, and appendicular skeletal mass in 9243 people who participated in the Korean National Health and Nutrition Examination Survey 2019-2021. Sarcopenia was defined according to the Asian Working Group for Sarcopenia's guidelines. Obesity was defined as a body fat percentage of ≥ 25% for men and ≥ 35% for women. RESULTS: The participants with chronic dizziness had a lower body mass index than those without (p = 0.001). Furthermore, sarcopenia was more common in those with chronic dizziness. In contrast, the degree of obesity was comparable in both groups. Multiple logistic regression analysis showed that sarcopenia was associated with a higher risk of chronic dizziness (odds ratio = 1.6, 95% confidence interval: 1.1-2.5; p = 0.026). DISCUSSION: Given the association of sarcopenia with chronic dizziness or imbalance, muscle mass may play a role in maintaining balance and stability. Physical exercise could be recommended to increase muscle mass in patients with chronic dizziness/imbalance and sarcopenia. Additional research is required to establish a causal relationship between chronic dizziness and sarcopenia.

Vestibular neuritis.

Vestibular neuritis is the most common cause of acute spontaneous vertigo. Vestibular neuritis is ascribed to acute unilateral loss of vestibular function, probably due to reactivation of herpes simplex virus in the vestibular ganglia. The diagnostic hallmarks of vestibular neuritis are spontaneous horizontal-torsional nystagmus beating away from the lesion side, abnormal head impulse test for the involved semicircular canals, ipsilesional caloric paresis, decreased responses of vestibular-evoked myogenic potentials during stimulation of the affected ear, and unsteadiness with a falling tendency toward the lesion side. Vestibular neuritis preferentially involves the superior vestibular labyrinth and its afferents. Accordingly, the function of the posterior semicircular canal and saccule, which constitute the inferior vestibular labyrinth, is mostly spared in vestibular neuritis. However, because the rare subtype of inferior vestibular neuritis lacks the typical features of vestibular neuritis, it may be misdiagnosed as a central vestibular disorder. Even in the patient with the typical pattern of spontaneous nystagmus observed in vestibular neuritis, brain imaging is indicated when the patient has unprecedented headache, negative head impulse test, severe unsteadiness, or no recovery within 1 to 2 days. Symptomatic medication is indicated only during the acute phase to relieve the vertigo and nausea/vomiting. Vestibular rehabilitation hastens the recovery. The efficacy of topical and systemic steroids requires further validation.

Pursuit-paretic and epileptic nystagmus in MELAS.

A 27-year-old man with MELAS 3243 mutation developed a right homonymous hemianopia, left beating nystagmus, and impaired smooth pursuit (SP) to the left. Intermittently, the left beating nystagmus changed to right beating with rightward eye and head deviation and associated altered mental status. Each episode lasted several minutes. MRI revealed restricted diffusion in left parieto-temporo-occipital cortices. During the ictus, electroencephalogram showed epileptic discharges in the left temporo-occipital region, and single photon emission computed tomography demonstrated hyperperfusion in the same area. The interictal left beating nystagmus may be ascribed to contralesional bias of SP imbalance since the parieto-temporo-occipital region is involved in the generation of SP. The ictal right beating nystagmus and rightward head and eye deviation indicate coactivation of the SP areas and parietal eye field. This report documents the novel co-occurrence of pursuit-paretic and epileptic nystagmus.

Prevention of recurrent benign paroxysmal positional vertigo with vitamin D supplementation: a meta-analysis.

RESEARCH BACKGROUND: Vitamin D insufficiency/deficiency is known to be related to occurrences and recurrences of benign paroxysmal positional vertigo (BPPV). However, the efficacy of vitamin D supplementation in reducing recurrences of BPPV remains to be established. We performed a meta-analysis to determine the therapeutic effects of vitamin D supplementation, with or without calcium, for preventing recurrences of BPPV. METHODS: We searched the PubMed, the Embase, the Web of Science and the reference lists of the articles. We included randomized or non-randomized trials that determined the efficacy of supplementing vitamin D or related compounds, alone or with calcium, in comparison to placebo or no intervention in preventing recurrences of BPPV. The primary outcome was the number of patients with BPPV recurrences. Data were collected and pooled using a weighted relative risk (RR) with corresponding 95% CIs, where possible, by adopting the fixed-effect or random-effect model according to the heterogeneity among the studies. The between-study heterogeneity was tested using the χ2 test and the I2 statistic, and funnel plots were used to evaluate any publication bias. RESULTS: We included five trials (four non-randomized trials and one randomized controlled trial) with a total of 1250 participants. The analyses showed a significant preventive effect on the recurrences of BPPV (RR = 0.37; 95% CI = 0.18-0.76; p = 0.007 with the random-effects model) with supplementation of vitamin D. Although a considerable heterogeneity was detected among the studies, the sensitivity analyses showed the reliability and stability of our results. CONCLUSIONS: Vitamin D supplementation provides a benefit for secondary prevention of BPPV. Supplementation of vitamin D should be considered in patients with frequent attacks of BPPV, especially when serum vitamin D is subnormal.

One-year prevalence and clinical characteristics in chronic dizziness: The 2019-2020 Korean National Health and Nutrition Examination Survey.

Introduction: In this cross-sectional study, we investigated the 1-year prevalence and related factors in the general population with an experience of chronic dizziness. Methods: This study analyzed persons (n = 5,163) who respond to dizziness and nutrition questionnaire from participant of Korean National Health and Nutrition Examination Survey (KNHANES, 2019-2020). Results: Of individuals over 40 years, 25.3% of the general population (61.6% females) reported either dizziness or imbalance for the past year. Moreover, 4.8% of the patients reported they suffered from chronic dizziness or imbalance for more than 3 months. In multiple regression analysis, patients with chronic dizziness were older, females, had lower body mass index (BMI), had stress awareness, and had a history of tinnitus within 1 year (>5 min per episode). Relative to normal body weight, both overweight and mild obesity (obesity stages 1 and 2) were associated with a significantly lower risk of chronic dizziness. Overweight, obesity stage 1, and obesity stage 2 had odds ratios of 0.549 [95% confidence interval (CI), 0.332-0.910], 0.445 (95% CI, 0.273-0.727), and 0.234 (95% CI, 0.070-0.779), respectively. Conclusions: In this study, the prevalence of chronic dizziness in the general population was 4.8%. Our study demonstrated that overweight and mild obesity were independently associated with a lower risk of chronic dizziness in adults for the past year. Therefore, the optimal BMI for patients with dizziness should be defined and managed according to an integrated care pathway.

Nystagmus and ataxia associated with antiganglioside antibodies.

BACKGROUND: Antiganglioside antibodies are found in various neurological disorders that constitute a continuum from peripheral neuropathy to encephalitis. However, nystagmus has rarely been described in patients with ataxia associated with antiganglioside antibodies. METHODS: From January 2008 to July 2009, we identified 3 patients with acute ataxia and nystagmus in 2 University Hospitals of Korea, who were found to have anti-GD1b, anti-GM1, or anti-GQ1b antibodies. RESULTS: In addition to acute ataxia, all 3 patients showed various combinations of nystagmus, which included central positional nystagmus (n = 3), vertical nystagmus (n = 1), and periodic alternating nystagmus (n = 1). The spontaneous and positional nystagmus were mostly detectable only with the elimination of fixation and magnification of the eyes using video goggles. Two patients also exhibited gaze-evoked nystagmus that was noticeable without the aid of video goggles. Patients had serum IgG antibodies to GD1b, GM1, or GQ1b. Cerebrospinal fluid examination, nerve conduction studies, and brain MRI were normal. In all patients, the symptoms and signs resolved over 3-12 months. CONCLUSIONS: Various forms of nystagmus with acute ataxia may be a sole or predominant manifestation of disorders related to antiganglioside antibodies. The nystagmus indicates a central pathology involving the cerebellum or brainstem in this antibody-associated disorder. Antiganglioside antibodies should be measured in patients with nystagmus and acute ataxia of undetermined etiology.

Update on Nystagmus and Other Ocular Oscillations.

This review reports on recent advances in understanding nystagmus and other involuntary eye movements. Advances in quantitative evaluations of eye movements using oculography, computational model simulations, genetics, and imaging technologies have markedly improved our understanding of the pathophysiology of involuntary eye movements, as well as their diagnosis and management. Patient-initiated capture of eye movements, especially when paroxysmal, and the online transfer of these data to clinicians would further enhance the ability to diagnose involuntary eye movements.