Vertigo and dizziness in adolescents: Risk factors and their population attributable risk

Characteristics and diagnostic approach of vestibular migraine in children and adolescents: A systematic review

OBJECTIVE

Vestibular migraine (VM) is the most common cause of episodic vertigo afflicts 1% of the general population. The complexity of VM is owing to the migrainous, and vestibular components and much knowledge have been gained in recent years on VM in the adult population. Akin to that, numerous studies focusing on VM in children and adolescent has emerged. We reviewed the literature to understand the characteristics and diagnostic approach of VM in children and adolescents.

METHODS

A literature search was conducted over a period of one month (April 2022).

RESULTS

16 articles were selected based on our objective and selection criteria. A total of patients was included, with a median age of 10.9 years. 11 studies diagnosed VM based on diagnostic criteria. Caloric test and electro/videonystagmography are the most favoured investigation used (50%). Imaging was performed in 56.2% of included studies.

CONCLUSION

Deciphering the ideal diagnostic approach for VM is prudent to ensure children and adolescents suffering from VM are treated earlier. VM can be diagnosed using the established diagnostic criteria, which requires thorough and meticulous history taking. The available oto-neurological examination aims to exclude other disorders as its significance in diagnosing VM is still debatable.

Relationship between periodontal disease and dizziness in Taiwanese adults: A nationwide population-based cohort study

Periodontal disease is often neglected and overlooking its initial symptoms can lead to tooth loss and systemic diseases. Patients with otitis media are at high risk of vestibular and balance dysfunction, consequently, and vertigo. Vertigo and dizziness are conditions with high reported incidences; they worsen with age and can burden health systems. The present study investigated whether periodontal disease causes dizziness. Research data covering 2008 through 2013 were retrieved from the National Health Insurance Research Database of Taiwan. Patients who were newly diagnosed as having periodontal disease or dizziness after at least 1 hospital admission or 3 outpatient visits were enrolled as participants. For our controls, we randomly selected individuals without periodontal disease who were sex- and age-matched with the investigated participants. In total, we enrolled 445 patients with periodontal disease and 1780 controls. The Kaplan-Meier curve indicated that the cumulative incidence of dizziness was significantly higher among the patients with periodontal disease relative to the controls. After adjustment for sex, age, income level, urbanization level, month of onset, and comorbidities, Cox proportional-hazards analysis revealed that patients with periodontal disease had an increased risk of dizziness (hazard ratio [HR]: 1.306, 95% confidence interval (CI): 1.155, 1.475). Compared with the controls, the risk of dizziness among patients with periodontal disease was higher for both female (HR: 1.439, 95%: 1.203, 1.720) and male patients (HR: 1.284, 95%: 1.123, 1.468); this risk was higher even when January (HR: 1.302, 95% CI: 1.145, 1.480), February (HR: 1.337, 95% CI: 1.178, 1.518), or March was excluded (HR: 1.308, 95% CI: 1.151, 1.487) and for patients without Ménière disease. Therefore, periodontal disease is not only a risk factor for dizziness but also an independent risk factor for dizziness. Future studies could clarify the mechanisms linking periodontal disease to dizziness.

The global prevalence of vestibular dysfunction in children and adolescents: a systematic review and meta-analysis

BACKGROUND

Vestibular dysfunction has been extensively studied amongst the older population. Recently, conditions and management of vestibular dysfunction among children and adolescent has gained attention. Yet, a lack of awareness and expertise in managing children and adolescents with vestibular dysfunction has led to a delay in diagnosis as well as a trifling prevalence rate.

AIM

To conduct a systematic review and meta-analyses to estimate the overall pooled prevalence of vestibular dysfunction in children and adolescents.

METHODS

PubMed, Scopus, and Web of Science databases were searched to identify studies published until 29 April 2022. We used a random-effects model to estimate the pooled prevalence with 95% confidence intervals (CIs). Heterogeneity was assessed using the I² statistic and Cochran's Q test. The robustness of the pooled estimates was checked by different subgroups and sensitivity analyses.

RESULTS

We identified 1811 studies, of which 39 studies (n = 323,663) were included in the meta-analysis. Overall, the pooled prevalence of children and adolescents with VD was 30.4% [95% CI 28.5-32.3%]. The age of the participants ranged from 1 to 19 years. Participants of the included 39 studies were from 15 countries. Among the studies, 34 were cross-sectional, and five were case-control designed. There were discrepancies found in the studies with objective (higher prevalence) versus subjective (lower prevalence) evaluations.

CONCLUSION

The prevalence of VD among children and adolescents was found to be 30.4% based on high-quality evidence. Due to the subjective assessment of most studies pooled in the analysis, the results should be interpreted cautiously until future comparative studies with objective assessments are carried out.

Etiological classification and management of dizziness in children: A systematic review and meta-analysis

Background

Dizziness in children, which could not be diagnosed at an early stage in the past, is becoming increasingly clear to a large extent. However, the recognition of the diagnosis and management remains discrepant and controversial due to their complicated and varied etiology. Central and peripheral vestibular disorders, psychogenic and systemic diseases, and genetic pathogeny constitute childhood etiological entities. Further understanding of the etiology and the prevalence of vertigo disorders is of crucial importance and benefit in the diagnosis and management of pediatric patients.

Methods

This systematic review and meta-analysis were conducted by systematically searching Embase, PubMed, the Cochrane Library, CNIK, the Chinese Wan-Fang database, CBM, the Chinese VIP database, and the Web of Science for literature on childhood vertigo disorders published up to May 2022. The literature was evaluated under strict screening and diagnostic criteria. Their quality was assessed using the Agency for Healthcare and Research Quality (AHRQ) standards. The test for homogeneity was conducted to determine the fixed effects model or random-effect model employed.

Results

Twenty-three retrospective cross-sectional studies involving 7,647 children with vertigo disorders were finally included, with an AHRQ score >4 (high or moderate quality). Our results demonstrated that peripheral vertigo (52.20%, 95% CI: 42.9-61.4%) was more common in children than central vertigo (28.7%, 95% CI: 20.8-37.4%), psychogenic vertigo (7.0%, 95% CI: 4.8-10.0%), and other systemic vertigo (4.7%, 95% CI: 2.6-8.2%). The five most common etiological diagnoses associated with peripheral vertigo included benign paroxysmal vertigo of childhood (BPVC) (19.50%, 95% CI: 13.5-28.3%), sinusitis-related diseases (10.7%, 95% CI: -11.2-32.6%), vestibular or semicircular canal dysfunction (9.20%, 95% CI: 5.7-15.0%), benign paroxysmal positional vertigo (BPPV)(7.20%, 95% CI: 3.9-11.5%), and orthostatic dysregulation (6.8%, 95% CI: 3.4-13.0%). Vestibular migraine (20.3%, 95% CI: 15.4-25.2%) was the most seen etiological diagnosis associated with central vertigo in children. In addition, we found the sex-based difference influenced the outcome of psychogenic vertigo and vestibular migraine, while there was no significant difference in other categories of the etiology. For the management of vertigo, symptomatical management is the first choice for most types of vertigo disorder in pediatrics.

Conclusion

Complex etiology and non-specific clinical manifestations of vertigo in pediatrics are challenging for their diagnoses. Reliable diagnosis and effective management depend on the close cooperation of multiple disciplines, combined with comprehensive consideration of the alternative characteristics of vertigo in children with growth and development.

Presence of physical symptoms in healthy adolescence found to be associated with female gender, obesity, tachycardia, diastolic hypertension and smoking

BACKGROUND

The goal of this study was to evaluate any association between physical symptoms and abnormal clinical history in adolescence undergoing screening echocardiography performed by Anthony Bates Foundation.

METHOD

The Anthony Bates Foundation has been performing screening echocardiography across the United States for the prevention of sudden death since 2001. We performed uni- and multivariate analysis to evaluate any association between physical symptoms with gender, smoking, obesity, heart rate, and hypertension.

RESULTS

We found a strong association between symptoms and the female gender (33% vs. 17.5% of males, P < 0.001). Furthermore, obesity (46.5% vs. 22.5%, P < 0.001), smoking (46.2% vs. 22.5%, P = 0.04), heart rate > 90 (34.8 vs. 22.8%, P = 0.001), and diastolic blood pressure > 90 (34.9% vs. 23.4%, P = 0.03) were all associated with symptoms. Increased systolic pressure was not associated with physical symptoms (24.3% vs. 21.9%, P = 0.4). Using multivariate analysis, female gender, diastolic blood pressure and obesity remained independently associated with physical symptoms. (Female gender: OR: 2.2, CI: 1.7-2.9, P < 0.001, obesity: OR: 2.5, CI 1.2-5.05, P = 0.009, and high diastolic blood pressure: OR: 2.08, CI 1.1-3.7, P = 0.01).

CONCLUSION

Physical symptoms are associated with smoking, female gender, obesity, tachycardia, and high diastolic blood pressure but not systolic pressure in adolescence undergoing routine screening echocardiography.

Risk factors for Meniere disease: a systematic review and meta-analysis

PURPOSE

To summarized the latest evidence of risk factors for developing MD.

METHODS

We searched Medline, the Cochrane Central Register of Controlled Trials (CENTRAL), Embase, CBM, VIP, WanFANG, and CNKI, and ClinicalTrials.gov. till June 2021 for cohort and case-control studies investigating risk factors for MD. The exposure group was participants with a clinical diagnosis of MD which was made according to the diagnostic scale of the Equilibrium Committee of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS), the control group was participants without MD. The outcome was determined by incidence or prognostic of MD. Paired reviewers independently screened citations, assessed bias risk of included studies using the Newcastle-Ottawa Scale. Odds ratios (OR), hazard ratios(HR), relative risk(RR) and 95% confidence interval (CI) were calculated for dichotomous data. The statistical analyses were carried out with the use of Review Manager 5.3. The level of statistical heterogeneity for pooled data were assessed by using I² statistics and Q-test.

RESULTS

768 abstracts and articles were identified by our search, of which 25 studies (n = 1, 471, 944) were included. There were 18 cohort studies, 7 case-control studies. Three distinct subgroups (age, sex, sleep) were identified. There were a total of two studies involving age, two studies involving gender and two studies involving sleep disorder. High to moderate methodological quality established that age [hazard ratios (HR) 2.21, 95% CI 1.85-2.65, I² = 0%] and sleep disorder[HR 1.68, 95% CI 1.47-1.93, I² = 0%] were risk factors for MD. While there was little evidence showing that sex was not a risk factor for MD [HR 1.61, 95% CI 0.91-2.84, I² = 74%].

CONCLUSION

The current evidence supports the suggestion that age and sleep disorder are risk factors for MD. Sex, gene, and hypothyroidism are tentative risk factors but conflicting/inconclusive results.

FUNDING

No external funding.

REGISTRATION

CRD42021248199 (Prospero).

Recurrent Vertigo of Childhood: Clinical features and prognosis

Introduction

“Recurrent Vertigo of Childhood” (RVC) has recently replaced the term “Benign Paroxysmal Vertigo of Childhood” and was defined as recurrent spells of vertigo without evidence of a vestibular migraine of childhood (VMC). RVC and VMC are considered the most frequent causes of vertigo and dizziness in children below 18 years of age. Diagnosis might be challenging since clinical features of RVC and VMC may overlap.

Objective

This study aims to characterize clinical and instrument-based findings in patients with RVC and to evaluate the course of the disorder.

Methods

We prospectively collected clinical and instrument-based data of children/adolescents younger than 18 years, who presented at the German Center for Vertigo and Balance Disorders (DSGZ) at the LMU University Hospital in Munich. All patients underwent a comprehensive neurological, ocular motor, vestibular and cochlear examination. Furthermore, findings from follow-up examinations were analyzed.

Results

Overall 42 children (24 male and 18 female) with RVC were included in the study. The mean age at diagnosis was 7 ± 3.6 years with a mean onset of symptoms at the age of 5.6 ± 3.4 years. Attack duration ranged between 1 min and 4 h. The most common accompanying symptoms included nausea, vomiting, expression of fear, and falls. Non-migrainous headaches were reported by 11 patients during initial presentation, 7 of whom were later diagnosed with migraine. Female patients showed a higher age at symptom onset, a higher attack frequency, and attack duration. Eleven of the 24 patients seen at a 3.5 year follow-up reported a complete cessation of attacks. Patients still experiencing vertigo attacks had a significantly reduced attack frequency, especially those who implemented at least one prophylactic measure.

Conclusion

A precise characterization of symptoms is essential for diagnosing children with RVC. Age at symptom onset does not exceed the age of 12. Gender-specific differences should be considered and may further support the evidence of an association with migraine. The disease course of RVC is benign, nevertheless implementing prophylactic measures such as regular exercise, increased fluid intake, sleep hygiene, and relaxation exercises, can improve attack frequency.

Hirudinea (Annelida) Fauna of Some Wetlands in Bingöl Province

OBJECTIVE

Leeches are important and reliable indicators of water quality and biodiversity in the ecosystem, so the presence of specific leech species is often closely related to basic water conditions and the presence of certain animals. This study was carried out in 2017 and 2018 in order to determine the Hirudinea fauna of some wetlands in Bingöl province. The investigation was conducted on a total of 13 stations.

METHODS

The water parameters of the stations were measured and recorded in situ. The collected specimens were brought alive to the Zoology Laboratory of Bingöl University Biology Department and kept alive under room temperature conditions. The diagnosis of leech samples was made through the living samples, and they were identified at the level of family, genus, and species.

RESULTS

During the study, seven species, belonging to six genera and in four families were recorded. These are; Hirudo verbana Carena, 1820, Glossiphonia complanata (L. 1758), Theromyzon tessulatum (O. F. Müller, 1774), Placopdella costata (Fr. Müller, 1846), Erpobdella octoculata (L., 1758), Erpobdella testacea (Savigny, 1820), Piscicola geometra (L., 1761).

CONCLUSION

The locations where the study was carried out are new records for the detected leech species.

Facts of Vertigo in Adolescents: Controversies and Challenges – A Narrative Review

Vertigo is a common complaint in the general population affecting 5% of adults in one year. At least 29.5% of adults have referred vertigo during life. Even though the prevalence of vertigo is well known in adults the epidemiologic data in adolescents is sparse. To date, it is known that adolescent females are usually affected by vertigo and some conditions such as depression and anxiety are found in this population. However, the lack of information about the prevalence of most common types of vertigo in adolescents, predisposing factors, challenges, and controversies in clinics in the literature, present a challenge for clinicians regarding the approach and follow-up of this population. Herein, we performed a literature review including data about the prevalence, most common types of vertigo and controversial events in the approach of vertigo in adolescents over the last two decades.

The clinical features and image characteristics of Meniere's disease patients with endolymphatic hydrops confirmed by enhanced magnetic resonance imaging

OBJECTIVES

To analyze and summarize the clinical features and image characteristics of Meniere's Disease (MD) patients with Endolymphatic Hydrops (EH) confirmed by enhanced Magnetic Resonance Imaging (MRI).

METHODS

252 MD patients with EH confirmed by MRI were enrolled. All patients met the diagnostic criteria for MD and underwent intravenous gadolinium injection. After 4 h, MR examinations were performed. The Nakashima grading standard was used to classify EH and evaluate its correlation with clinical features.

RESULTS

Different degrees of EH were shown in all MD patients, and 157 of the 252 (62.3%) patients showed significant EH, 95 of the 252 (37.7%) patients showed mild EH. Only 89 (35.3%) met the diagnostic criteria for definite MD, and the remaining 163 (64.7%) patients met the diagnostic criteria for probable MD. Compared with patients with unilateral EH, the symptoms of the first affected ear of patients with bilateral EH were more serious. The degree of EH was related to the degree of hearing loss (p < 0.05).

CONCLUSION

MRI with intravenous gadolinium injection can provide a better assessment of EH in MD patients. The clinical features of MD patients with EH confirmed by enhanced MRI did not fully meet the existing diagnostic criteria for definite MD. Including the diagnosis of EH in the diagnostic criteria of MD can increase the diagnosis rate of MD. The degree and distribution of EH may be related to the degree of hearing loss.

LEVEL OF EVIDENCE

4.

Vertigo in Patients with Degenerative Cervical Myelopathy

(1) Background: Cervical vertigo (CV) represents a controversial entity, with a prevalence ranging from reported high frequency to negation of CV existence. (2) Objectives: To assess the prevalence and cause of vertigo in patients with a manifest form of severe cervical spondylosis-degenerative cervical myelopathy (DCM) with special focus on CV. (3) Methods: The study included 38 DCM patients. The presence and character of vertigo were explored with a dedicated questionnaire. The cervical torsion test was used to verify the role of neck proprioceptors, and ultrasound examinations of vertebral arteries to assess the role of arteriosclerotic stenotic changes as hypothetical mechanisms of CV. All patients with vertigo underwent a detailed diagnostic work-up to investigate the cause of vertigo. (4) Results: Symptoms of vertigo were described by 18 patients (47%). Causes of vertigo included: orthostatic dizziness in eight (22%), hypertension in five (14%), benign paroxysmal positional vertigo in four (11%) and psychogenic dizziness in one patient (3%). No patient responded positively to the cervical torsion test or showed significant stenosis of vertebral arteries. (5) Conclusions: Despite the high prevalence of vertigo in patients with DCM, the aetiology in all cases could be attributed to causes outside cervical spine and related nerve structures, thus confirming the assumption that CV is over-diagnosed.

Clinical and demographic characteristics of children and adolescents with acute vertigo symptoms: A cross-sectional study

Background/aim

Vertigo is one of the rarely diagnosed disorders during childhood due to insufficient description of the children regarding their experiences to the physicians. The clinical features of children and adolescents admitted by acute vertigo symptoms were investigated to elaborate the subject retrospectively.

Materials and methods

Between January 2017–July 2019, records of cases admitted with acute vertigo complaints to pediatric neurology were retrospectively examined.

Results

Of 761 patients, mean age was 13.8 years, 64% (n = 487) were women, 22.6% (n = 172) of which were children (1–11 years). A total of 37.3% of the cases (n = 284) had unknown etiology of acute vertigo symptoms, 39.6% (n = 301) had acute vertigo, and 23.1% (n = 176) were considered with no organicity problems but a group of the families stopped cooperating to the full extent in the study. Among all the patients, 25.6% (195/761) had paroxymal vertigo, 6.8% (52/761) had migraine-associated vertigo, 4.5% (34/761) had psychogenic vertigo, and 2.6% (20/761) had epileptic vertigo. Epileptic vertigo was significantly higher in younger children (mean age = 10.6, F(3) = 8874, P < .001), and the ratio of its occurence was also higher among children (60%, χ2 (3) = 20.347, P < .001).

Conclusion

Vertigo complaints are 1.7 times more common among the girls. Epileptic vertigo is significantly higher among the children. Among younger children, it seems important to consider epilepsy when vertigo emerged.

Bullying, health complaints, and self-rated health among school-aged children and adolescents

Objective

The aim of the current study was to examine whether health complaints and self-reported health were associated with bullying victimization in a large cohort of Icelandic children and adolescents.

Methods

In this study, we used data from a school-based cross-sectional survey, specifically, the Icelandic contribution to the international research network Health Behavior in School-aged Children (HBSC). The study population included all students throughout Iceland in grades 6, 8, and 10 (mean age 13 years, standard deviation 1.61). The participation rate was 84% (N = 11,018). Participating students completed an anonymous standardized questionnaire in their classrooms.

Results

Bullying victimization was associated with feeling depressed (odds ratio 2.61), having difficulty falling asleep, dizziness, and low self-reported health. No differences were found between sex and age groups.

Conclusions

Children and adolescents who are bullied appear to more often experience depression, difficulties falling asleep, dizziness, and poor health; however, health complaints were also relatively high among non-bullied children and adolescents. Bullying prevention measures must be implemented in children’s and adolescents’ social environments. In addition to assessing bullying interventions, further research should focus on methods of enhancing resilience in this population.

Peripheral Vestibular Disorders: Nationwide Evidence From Taiwan

OBJECTIVES/HYPOTHESIS

This study aimed to evaluate the prevalence of peripheral vestibular disorders in an Asian population of predominantly Han Chinese ethnicity.

STUDY DESIGN

Cross-sectional study.

METHODS

Patients with a peripheral vertigo disorder were identified from the Taiwan Health Insurance Research Database, a database of all medical claims of a randomly selected, population-representative sample of 2 million enrollees of Taiwan's National Health Insurance system covering over 99% of Taiwan's citizens. In 2016, 59,986 patients received a diagnosis of peripheral vestibular disorders in Taiwan. We calculated the population-wide prevalence rates of peripheral vestibular disorders in 2016 by sex and age group (20 to 24, 25 to 29, 30 to 34, 35 to 39, 40 to 44, 45 to 49, 50 to 54, 55 to 59, 60 to 64, 65 to 69, and ≥ 70 years) stratified into five urbanization levels.

RESULTS

The prevalence rate of peripheral vestibular disorders was 2,833.4 per 100,000 population during the year. Prevalence of Meniere's disease was 70.4 per 100,000, benign paroxysmal positional vertigo, 446.4, vestibular neuritis 307.2, and other or unspecified peripheral vestibular dizziness, 2,009.5 per 100,000. Prevalence rates steadily increased with age for every type of peripheral vestibular disorder, and were higher among females compared to males. The female-to-male gender ratios were 1.84, 1.89, and 1.93 for Meniere's disease, vestibular neuritis, and other peripheral vestibular dizziness, respectively. Counties with the lowest urbanization level had the highest prevalence rates of all types of peripheral vestibular disorders except vestibular neuritis.

CONCLUSIONS

Results showed that peripheral vestibular disorders are common in Taiwan, increase with age, are predominantly female, and show higher prevalence in rural areas.

LEVEL OF EVIDENCE

2b Laryngoscope, 131:639-643, 2021.

The Association between Sleep Duration and Dizziness in Korean Women: The Korea National Health and Nutrition Examination Survey

BACKGROUND

The aim of this study was to investigate the association between sleep duration and dizziness in a representative Korean population.

METHODS

We analyzed data from the Korea National Health and Nutrition Examination Surveys (2010-2012). A total of 12,499 adults who completed otolaryngologic examinations were evaluated.

RESULTS

Both men and women with severely short sleep duration (≤ 5 hours) and severely long sleep duration (≥ 9 hours) tended to have higher dizziness prevalence. However, the adjusted odds ratio (OR) for sleep duration was only significant in women with dizziness after adjusting for confounders. Compared to that in an optimal sleep group (6-8 hr/day), the OR (95% confidence interval) for dizziness prevalence after adjusting for age and health behaviors (body mass index, smoking habit, alcohol consumption, level of exercise, metabolic syndrome, and tinnitus) was 1.473 (1.194-1.818) for the severely short sleep group (≤ 5 hr/day) and 1.472 (1.078-2.009) for the severely long sleep group (≥ 9 hr/day) only in women.

CONCLUSION

In the Korean population, dizziness was associated with shorter or longer sleep durations only among women. Further epidemiologic and experimental studies are necessary to clarify the impact of dizziness on sleep disorders.

Epidemiology of Vestibular Impairments in a Pediatric Population

The purpose of this study was to report the prevalence of vestibular impairment (VI) in children ( n  = 2,528) referred for complete vestibular testing because of balance disorders (BD) or hearing loss (H). A VI was shown in 51.5% of the children tested (1,304/2,528). For BD (e.g., vertigo, dizziness, instability, delay in posturomotor development), VI was found in 36.5% ( n  = 379/1,037). The most frequent causes of BD with VI included inner ear malformation (13.5%), delay in posturomotor development (13.4%), hearing loss revealed with vertigo (3.9%), trauma (3.9%), vestibular neuritis (3.3%), meningitis (2.5%), Meniere-like syndrome (1.1%), BPPV posttrauma (1%), labyrinthitis (0.4%), and unknown etiology (19.6%). Normal responses to the complete battery of tests ( n  = 658, 63.5%) excluded a vestibular origin to BD, leading to other diagnoses: principally migraine (15.6%), ophthalmological disorders (15.1%), neurological disorders (including delay in posturomotor development; 14.4%), orthostatic hypotension, or somatoform dizziness (<1%). Of the children referred for hearing loss ( n  = 1,491), 68.5% were tested without cochlear implantation (CI; n  = 1,022). In this group, 54.5% presented with VI ( n  = 557). This was mostly found in cytomegalovirus infection, inner ear malformation, and genetic syndromes. Profound hearing loss candidates for cochlear implants had complete bilateral vestibular loss in 20% and delay in posturomotor development, and 80% had partial or normal vestibular function and normal posturomotor development. VI was found after CI in 50% on the side of the implant (partial in 41% and complete in 9%). VI is present in 36.5% of children referred to our center for BDs and 54.5% for hearing loss. Vestibular testing permits ruling out peripheral VI and hence seeking other causes for BDs such as migraine and ophthalmological disorders and also helps lower the risk of inducing bilateral complete vestibular loss in CI protocols.