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.

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.

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.

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.

Secondary hypoxic ischemia alters neurobehavioral outcomes, neuroinflammation, and oxidative stress in mice exposed to controlled cortical impact.

OBJECTIVE: Hypoxic ischemia (HI) is a secondary insult that can cause fatal neurologic outcomes after traumatic brain injury (TBI), ranging from mild cognitive deficits to persistent vegetative states. We here aimed to unravel the underlying pathological mechanisms of HI injury in a TBI mouse model. METHODS: Neurobehavior, neuroinflammation, and oxidative stress were assessed in a mouse model of controlled cortical impact (CCI) injury followed by HI. Mice underwent CCI alone, CCI followed by HI, HI alone, or sham operation. HI was induced by one-vessel carotid ligation with 1 hour of 8% oxygen in nitrogen. Learning and memory were assessed using the novel object recognition test, contextual and cued fear conditioning, and Barnes maze test. Brain cytokine production and oxidative stress-related components were measured. RESULTS: Compared to TBI-only animals, TBI followed by HI mice exhibited significantly poorer survival and health scores, spatial learning and memory in the Barnes maze test, discrimination memory in the novel object recognition test, and fear memory following contextual and cued fear conditioning. Malondialdehyde levels were significantly lower, whereas glutathione peroxidase activity was significantly higher in TBI followed by HI mice compared to TBI-only and sham counterparts, respectively. Interleukin-6 levels were significantly higher in TBI followed by HI mice compared to both TBI-only and sham animals. CONCLUSION: Post-traumatic HI aggravated deficits in spatial, fear, and discrimination memory in an experimental TBI mouse model. Our results suggest that increased neuroinflammation and oxidative stress contribute to HI-induced neurobehavioral impairments after TBI.

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.

Benign Paroxysmal Positional Vertigo Risk Factors Unique to Perimenopausal Women.

Many investigations have found common occurrences of benign paroxysmal positional vertigo (BPPV) in women, and clinical experience has shown that BPPV can develop due to increased hormonal fluctuations, especially during menopause. Therefore, knowledge about neurochemicals and their involvement with BPPV is imperative for the management of neurological issues in women. This review will discuss appropriate gender-based considerations of BPPV based on experimental and clinical evidence. The studies describe 2 lines of evidence regarding the association of perimenopause in women and the development of BPPV: (1) experimental evidence: the existence of estrogen receptors in the inner ear, otoconial malformations in osteopenic/osteoporotic rats, changes in otoconin 90 caused by hormone replacement therapy, and impaired calcium absorption following estrogen deprivation corrected by estrogen replacement therapy and (2) clinical evidence: epidemiological aspects, osteoporosis and estrogen deficiency. Future studies are necessary to validate the effects of hormonal replacement therapy and phytoestrogen in women with recurrent BPPV.

Prevention of benign paroxysmal positional vertigo with vitamin D supplementation: A randomized trial.

OBJECTIVE: To assess the effect of vitamin D and calcium supplementation in preventing recurrences of benign paroxysmal positional vertigo (BPPV). METHODS: We performed an investigator-initiated, blinded-outcome assessor, parallel, multicenter, randomized controlled trial in 8 hospitals between December 2013 and May 2017. Patients with confirmed BPPV were randomly assigned to the intervention (n = 518) or the observation (n = 532) group after successful treatment with canalith repositioning maneuvers. The primary outcome was the annual recurrence rate (ARR). Patients in the intervention group had taken vitamin D 400 IU and 500 mg of calcium carbonate twice a day for 1 year when serum vitamin D level was lower than 20 ng/mL. Patients in the observation group were assigned to follow-ups without further vitamin D evaluation or supplementation. RESULTS: The intervention group showed a reduction in the ARR (0.83 [95% confidence interval (CI), 0.74-0.92] vs 1.10 [95% CI, 1.00-1.19] recurrences per 1 person-year) with an incidence rate ratio of 0.76 (95% CI, 0.66-0.87, p < 0.001) and an absolute rate ratio of -0.27 (-0.40 to -0.14) from intention-to-treat analysis. The number needed to treat was 3.70 (95% CI, 2.50-7.14). The proportion of patients with recurrence was also lower in the intervention than in the observation group (37.8 vs 46.7%, p = 0.005). CONCLUSIONS: Supplementation of vitamin D and calcium may be considered in patients with frequent attacks of BPPV, especially when serum vitamin D is subnormal. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for patients with BPPV, vitamin D and calcium supplementation reduces recurrences of BPPV.

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.

Exploratory, cognitive, and depressive-like behaviors in adult and pediatric mice exposed to controlled cortical impact.

OBJECTIVE: Sequelae of behavioral impairments associated with human traumatic brain injury (TBI) include neurobehavioral problems. We compared exploratory, cognitive, and depressive-like behaviors in pediatric and adult male mice exposed to controlled cortical impact (CCI). METHODS: Pediatric (21 to 25 days old) and adult (8 to 12 weeks old) male C57Bl/6 mice underwent CCI at a 2-mm depth of deflection. Hematoxylin and eosin staining was performed 3 to 7 days after recovery from CCI, and injury volume was analyzed using ImageJ. Neurobehavioral characterization after CCI was performed using the Barnes maze test (BMT), passive avoidance test, open-field test, light/dark test, tail suspension test, and rotarod test. Acutely and subacutely (3 and 7 days after CCI, respectively), CCI mice showed graded injury compared to sham mice for all analyzed deflection depths. RESULTS: Time-dependent differences in injury volume were noted between 3 and 7 days following 2-mm TBI in adult mice. In the BMT, 2-mm TBI adults showed spatial memory deficits compared to sham adults (P<0.05). However, no difference in spatial learning and memory was found between sham and 2-mm CCI groups among pediatric mice. The open-field test, light/dark test, and tail suspension test did not reveal differences in anxiety-like behaviors in both age groups. CONCLUSION: Our findings revealed a graded injury response in both age groups. The BMT was an efficient cognitive test for assessing spatial/non-spatial learning following CCI in adult mice; however, spatial learning impairments in pediatric mice could not be assessed.

Acquired Ocular Motor Nerve Palsy in Neurology Clinics: A Prospective Multicenter Study.

BACKGROUND AND PURPOSE: This study aimed to determine the patterns and etiologies of acquired ocular motor nerve palsy (OMNP) diagnosed in neurology clinics. We also investigated the clinical features that may predict the causes other than microvascular ischemia in isolated OMNP. METHODS: We performed a prospective multicenter study that had recruited 298 patients with acquired OMNP from the neurology clinics of referral-based 9 university hospitals in Korea. We finally selected 235 patients with isolated OMNP and divided them into older (age ≥50 years, n=188) and younger (age <50 years, n=47) groups. We investigated the underlying etiologies of acquired OMNP. We also estimated the frequency of microvascular ischemia and other causes in isolated OMNP, and sought to determine the clinical features that can predict the causes other than microvascular ischemia. RESULTS: Abducens nerve palsy was the most common (40%) of the acquired OMNPs, followed by oculomotor nerve palsy (27%), trochlear nerve palsy (23%), and multiple OMNPs (10%). The etiologies included microvascular ischemia (47%), inflammatory (21%), stroke (5%), trauma (5%), neoplasm (3%), and others (2%), with the cause not being determined in 13% of the patients. Microvascular ischemia was the most common cause (83%) in patients aged ≥50 years with isolated OMNP, followed by inflammation (6%), stroke (6%), neoplasm (3%), and aneurysm (1%). Microvascular ischemia was more common in the older than the younger group (83% vs. 49%, p<0.001). The intensity of headache was the only risk factor for causes other than microvascular ischemia in isolated OMNP. CONCLUSIONS: Vascular and inflammatory disorders are the most common causes of acquired OMNP diagnosed in neurology clinics. Microvascular ischemia was the predominant cause of isolated OMNP. Severe headache indicates causes other than microvascular ischemia in isolated OMNP.

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.

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.

Correction to: Characteristics of single ocular motor nerve palsy associated with anti-GQ1b antibody.

The original version of this article unfortunately contained a mistake.

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.

Characteristics of single ocular motor nerve palsy associated with anti-GQ1b antibody.

To define the prevalence and characteristics of single ocular motor nerve palsy (OMNP) associated with positive serum anti-GQ1b antibody. We performed a prospective multicenter study that recruited 82 patients with single OMNP without identifiable causes from the history and neuroimaging in six neurology clinics of university hospitals. We measured serum anti-GQ1b antibody in all participants. Twelve patients with multiple OMNP and 30 with identifiable causes served as the controls. Overall, the prevalence of anti-GQ1b antibody syndrome was 10% (8/82) in patients with single OMNP and 6% (5/78) in those with single OMNP in isolation. None of the 14 patients with OMNP with identifiable causes showed positive serum anti-GQ1b antibody. The prevalence of anti-GQ1b antibody syndrome was much higher in patients with multiple OMNP than in those with single OMNP (50% vs. 10%, p < 0.01). Patients with single OMNP and positive anti-GQ1b antibody are younger (42 ± 16 vs. 58 ± 15, p < 0.05) and had a significantly higher frequency of preceding infection (75 vs. 19%, p < 0.05) and other neurological signs (38 vs. 1%, p < 0.05) than those with negative antibody. Eight patients with single OMNP and positive serum anti-GQ1b antibody involved the abducens (n = 6), trochlear (n = 1), or oculomotor nerve (n = 1). Single OMNP accompanying other neurological signs and multiple OMNP are more likely to be associated with anti-GQ1b antibody. Anti-GQ1b antibody syndrome should be considered even in patients with single OMNP, especially when antecedent infection was associated in younger patients.

Effect of Prophylactic Medication on Associated Dizziness and Motion Sickness in Migraine.

OBJECTIVE: To determine the efficacy of prophylactic medications for migraine in reducing associated dizziness and motion sickness. STUDY DESIGN: Multicenter prospective observational study. SETTING: Nationwide 9 Dizziness Clinics in South Korea. PATIENTS: One hundred thirty-eight patients who required a preventive medication for migraine accompanied by dizziness and motion sickness. INTERVENTION: At least one of the prophylactic medications was prescribed among the beta-blockers, calcium channel blockers, tricyclic antidepressants, and antiepileptic drugs. MAIN OUTCOME MEASURE: For 3 months from the index visit, the patients had monthly assessments of the headache (frequency and duration), dizziness handicap inventory, University of California Los Angeles dizziness questionnaire, vertigo symptom scale, and motion sickness score. RESULTS: The prophylactic medications significantly improved the headache profiles, all three parameters of dizziness (dizziness handicap inventory, University of California Los Angeles dizziness questionnaire, and vertigo symptom scale), and severity of motion sickness (p < 0.001). CONCLUSION: The prophylactic medication for migraine also improves associated dizziness and motion sickness as well as the headaches.