Correlates of psychiatric hospitalization in a clinical sample of Canadian adolescents with bipolar disorder

Objective

To identify factors associated with psychiatric hospitalization among adolescents with bipolar disorder (BD).

Methods

Participants were 100 adolescents, ages 13–19, who fulfilled DSM-IV criteria for bipolar I disorder [(BD-I), n = 26], bipolar II disorder [(BD-II), n = 40], or operationalized criteria for BD not otherwise specified [(BD-NOS), n = 34], via the Schedule for Affective Disorders and Schizophrenia, Present and Lifetime version (KSADS-PL). Demographic, clinical, and family history variables were measured via clinical interview with the participant and a parent or guardian.

Results

The lifetime prevalence of psychiatric hospitalization was 50%. Significant predictors of psychiatric hospitalization in univariate analyses included older age, BD-I, history of suicide attempt, psychosis, lifetime use of second generation antipsychotics (SGAs), lithium, SSRI antidepressants and any medication. BD-II was negatively associated with psychiatric hospitalization. In multivariable analyses, older age, history of suicide attempt, psychosis and use of SGAs were positively associated with hospitalization, whereas BD-II was negatively associated with hospitalization.

Conclusions

Psychiatric hospitalization in adolescents with BD is highly prevalent and associated with older age and proxies for greater illness severity. Further studies are needed to identify strategies for reducing the need for psychiatric hospitalizations among adolescents with BD.     

Typical and atypical antipsychotics differentially affect long-term incidence rates of the metabolic syndrome in first-episode patients with schizophrenia: a retrospective chart review

The presence of the metabolic syndrome (MetS) is an important risk factor for cardiovascular disease and diabetes. There are limited data on the prevalence of MetS in patients with schizophrenia at the onset of the disorder and specifically no data on patients treated in the era when only first-generation antipsychotics were available.

Methods

Data from a historic cohort of consecutively admitted first-episode patients with schizophrenia treated with first-generation antipsychotics (FGAs) were compared with an age and sex matched series of consecutive first-episode patients treated only with second-generation antipsychotics (SGAs). Rates of MetS were compared at baseline and after on average 3 years of treatment exposure.

Results

At first episode there was no difference in the prevalence of MetS between the historic and the current cohort. Rates of MetS increased over time in both groups, but patients started on SGAs had a three times higher incidence rate of MetS (Odds Ratio 3.6, CI 1.7–7.5). The average increase in weight and body mass index was twice as high in patients started on SGA. The difference between the FGA and SGA group was no longer significant when patients started on clozapine and olanzapine were excluded.

Conclusion

Rates of MetS at the first episode of schizophrenia today are not different from those of patients 15 to 20 years ago. This finding counters the notion that the high rates of metabolic abnormalities in patients with schizophrenia currently reported are mainly due to lifestyle changes over time in the general population. Some SGAs have a significantly more negative impact on the incidence of MetS compared to FGAs in first-episode patients.     

Cerebral cortical gray expansion associated with two second-generation antipsychotics.

BACKGROUND: Second-generation antipsychotics (SGAs) differ from first-generation antipsychotics (FGAs) with respect to induction of less extrapyramidal morbidity, partially reducing negative symptoms, and causing modest improvement in neurocognitive functioning in patients with schizophrenia. SGAs demonstrate 5-HT2a antagonism. Differential effects of SGAs and FGAs on cortical gray volumes are explored herein. METHODS: Cerebral cortical gray was examined volumetrically in 19 patients with schizophrenia before and following 28 days of treatment with two SGAs (risperidone and ziprasidone; n = 13) or a FGA (haloperidol; n = 6). Seven (untreated) control subjects were also assessed at a similar interval. RESULTS: During treatment with the SGAs risperidone and ziprasidone, cerebral cortical gray of 13 patients with schizophrenia expanded 20.6 +/- 11.4 cc (p < .0005). Six patients receiving the FGA haloperidol, as well as 7 control subjects, showed no change in cortical gray volumes (p = .983 and p = .932, respectively) at the time of reassessment. CONCLUSIONS: Volumetric increase of cerebral cortical gray occurred early in the course of treatment with the SGAs ziprasidone and risperidone, but not with the FGA haloperidol. Such cortical gray expansion may be relevant to the reported enhanced neurocognition and quality of life associated with SGA treatment.     

Effects of tapering of long-term benzodiazepines on cognitive function in patients with schizophrenia receiving a second-generation antipsychotic

Background

The high use of long-term benzodiazepines (BZDs) with second-generation antipsychotics (SGAs) has been identified as an important issue in the treatment of schizophrenia in Japan. The aim of this study was to evaluate the effects of gradual reduction or discontinuation of daytime BZD use on cognitive function and quality of life (QOL) in patients with chronic schizophrenia receiving an SGA.

Methods

Thirty schizophrenic patients who had received an SGA with concomitant BZDs for at least 3 months were enrolled. Before and 4 weeks after tapering of daytime BZDs, the Brief Assessment of Cognition in Schizophrenia Japanese-language version (BACS-J) and the Schizophrenia Quality of Life Scale Japanese-language version (SQLS-J) were administered. Clinical evaluation also included the Positive and Negative Syndrome Scale (PANSS). To compare for practice effects on the BACS-J, 10 patients with chronic schizophrenia were assessed without tapering BZDs.

Results

BZDs were reduced or discontinued safely in most patients, and no emergent withdrawal symptoms were observed. Significant improvements were shown in verbal memory, working memory, and composite score, as measured by the BACS-J without practice effects. In addition, the motivation/energy score on the SQLS-J, the negative symptoms and total scores on the PANSS significantly improved after tapering BZDs.

Conclusion

Reduction or discontinuation of long-term daytime use of BZDs may be warranted in patients with schizophrenia treated with SGAs, as it may improve cognitive function, subjective QOL, and psychiatric symptoms with no significant adverse effects.     

The Effectiveness of Cross-Tapering Switching to Ziprasidone in Patients with Schizophrenia or Schizoaffective Disorder

Objective

Switching antipsychotics is one useful therapeutic option when the treatment of schizophrenia encounters suboptimal efficacy and intolerability issues. This study aimed to investigate the efficacy and tolerability of cross-tapering switching to ziprasidone from other antipsychotics.

Methods

A total of 67 patients with schizophrenia or schizoaffective disorder were recruited in this 12-week, multicenter, non-comparative, open-label trial. Prior antipsychotics were allowed to be maintained for up to 4 weeks during the titration of ziprasidone. Efficacy was primarily measured using the 18-item Brief Psychotic Rating Scale (BPRS) at baseline, 4 weeks, 8 weeks, and 12 weeks. Efficacy was secondarily measured by the Clinical Global Impression-Severity (CGI-S) scale and the Global Assessment of Functioning (GAF) scale at each visit. Regarding the metabolic effects of switching to ziprasidone, weight, body mass index (BMI), waist-to-hip ratio (WHR), and lipid profile-including triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and total cholesterol levels-were measured at each follow-up visit.

Results

The BPRS scores were significantly improved at 12 weeks after switching to ziprasidone (F=5.96, df=2.11, p=0.003), whereas the CGI-S and GAF scores were not significantly changed. BMIs, WHRs, and TG levels were significantly decreased, with no significant changes in other lipid profiles.

Conclusion

Cross-tapering switching to ziprasidone is effective for patients with schizophrenia spectrum disorders. Beyond the efficacy of the procedure, favorable metabolic profiles show that switching to ziprasidone may be helpful for maintenance therapy over an extended period.     

The relationship between actigraphically defined sleep disturbance and REM sleep behaviour disorder in Parkinson's Disease

Aim

In this study, we sought to evaluate the utility of actigraphy for examining symptoms of rapid eye movement sleep behaviour disorder (RSBD).

Methods

Twenty-two patients with idiopathic Parkinson's Disease (mean age = 63.4 years, SD = 7.5) underwent neurological assessment and completed sleep diaries, self-report sleep questionnaires and 2-weeks of actigraphy. They also completed the rapid eye movement sleep behavior disorder questionnaire and were classified as screening negative (RSBD−, n = 9) or positive (RSBD+, n = 13) for RSBD according to published criteria. Key outcome data were the number of wake bouts and duration of arousals during the sleep interval as determined by actigraphy.

Results

Patients classified as RSBD+ demonstrated a higher number of wake bouts than those who were RSBD− (p = 0.011).

Conclusions

These results suggest that actigraphy may be a viable tool to assist in the early identification of RSBD. In turn, this could guide early intervention approaches.     

Antipsychotic prophylaxis in surgical patients modestly decreases delirium incidence — but not duration — in high-incidence samples: A meta-analysis

Objective

The objective was to examine whether prophylactic treatment with antipsychotics can decrease the incidence and severity of postsurgical delirium.

Method

A meta-analysis of existing trials comparing delirium incidence between patients given prophylactic antipsychotic and placebo was performed. Secondary outcomes were total hospital days, total days of delirium and severity. Pooled odds ratios (ORs) and mean differences were calculated using a random-effects model.

Results

Five randomized placebo-controlled trials comprising a total of 1491 patients were included. In the pooled analysis, prophylactic antipsychotic administration showed a reduction in delirium incidence (OR: 0.42; 95% confidence interval (CI): 0.24, 0.74). Among the studies reporting other outcomes, patients receiving antipsychotics prophylactically showed no differences in total hospital days (0.1; 95% CI: − 0.73, 0.94), days of delirium (− 1.17; 95% CI: − 5.22, 2.88) or delirium severity (− 1.02; 95% CI: − 6.81, 4.76).

Conclusions

Prophylactic antipsychotic treatment in surgical patients modestly decreases the incidence of delirium, but not the length of hospital stay, duration of delirium or its severity. Given the modest protective effect of antipsychotics and their potential adverse reactions, there is insufficient evidence to support its universal use as a preventive agent, though potential benefit may be seen in populations at high risk of developing delirium.     

Undiagnosed and comorbid disorders in patients with presumed chronic fatigue syndrome

Objective

To assess undiagnosed and comorbid disorders in patients referred to a tertiary care center with a presumed diagnosis of chronic fatigue syndrome (CFS).

Methods

Patients referred for chronic unexplained fatigue entered an integrated diagnostic pathway, including internal medicine assessment, psychodiagnostic screening, physiotherapeutic assessment and polysomnography + multiple sleep latency testing. Final diagnosis resulted from a multidisciplinary team discussion. Fukuda criteria were used for the diagnosis of CFS, DSM-IV-TR criteria for psychiatric disorders, ICSD-2 criteria for sleep disorders.

Results

Out of 377 patients referred, 279 (74.0%) were included in the study [84.9% female; mean age 38.8 years (SD 10.3)].A diagnosis of unequivocal CFS was made in 23.3%. In 21.1%, CFS was associated with a sleep disorder and/or psychiatric disorder, not invalidating the diagnosis of CFS. A predominant sleep disorder was found in 9.7%, 19.0% had a psychiatric disorder and 20.8% a combination of both. Only 2.2% was diagnosed with a classical internal disease.In the total sample, a sleep disorder was found in 49.8%, especially obstructive sleep apnea syndrome, followed by psychophysiologic insomnia and periodic limb movement disorder. A psychiatric disorder was diagnosed in 45.2%; mostly mood and anxiety disorder.

Conclusions

A multidisciplinary approach to presumed CFS yields unequivocal CFS in only a minority of patients, and reveals a broad spectrum of exclusionary or comorbid conditions within the domains of sleep medicine and psychiatry. These findings favor a systematic diagnostic approach to CFS, suitable to identify a wide range of diagnostic categories that may be subject to dedicated care.     

Posterior SMA Syndrome following subcortical stroke: Contralateral akinesia reversed by visual feedback

Background

The supplementary motor area (SMA) plays a key role in motor programming and production and is involved in internally-cued movements. In neurological populations, SMA syndrome following a lesion to the “SMA proper” is characterized by transient impairment of voluntary movements and motor sequences. This syndrome is assumed to follow on from an interruption of the motor cortico-subcortical loop, and some case reports indicate that such a syndrome could occur after a brain lesion isolating the SMA from subcortical structures.

Aim

To characterize the pattern of motor impairments in a patient whose stroke disconnects the SMA from the subcortical motor loop.

Method

A patient developed a moderate transient left hemiparesis following a subcortical stroke in the right anterior cerebral artery area, which disconnected the SMA from basal ganglia. Eight days after the stroke, when the hemiparesis had regressed, the patient presented a specific SMA motor disorder of the left hand which manifested as an akinesia and was exacerbated when his visual attention was not directed towards his hand. We assessed finger tapping with left and right hands, eyes closed and open, in the left and right hemispace. We indexed movement speed as the number of taps filmed over 5-s periods.

Results

Left motor weakness (grasping strength of right hand: 49 kg and left hand: 41 kg) was resolved in a week. Ideomotor and ideational gestures and motor sequences were preserved. On the tapping task, left-hand tapping was slower than right-hand tapping. Critically, visual feedback improved tapping speed for the left, but not for the right, hand. The hemispace of the task execution had no effect on tapping performance.

Conclusion

Our results suggest that SMA-basal ganglia disconnection decreases contralateral movement initiation and maintenance and this effect is partly compensated by visual cues.     

Sex differences and eating disorder risk among psychiatric conditions,compulsive behaviors and substance use in a screened Canadian national sample

Objective

This study examined sex differences and eating disorder risk among psychiatric conditions, compulsive behaviors (i.e., gambling, suicide thoughts and attempts) and substance use in a nationally representative sample.

Method

Data from participants of the Canadian Community Health Survey Cycle 1.2 who completed the Eating Attitudes Test (n= 5116) were analyzed. Sex differences were compared among psychiatric comorbidities according to eating disorder risk, binging, vomiting and dieting behavior. Poisson regression analysis provided prevalence ratios (PRs) of disordered eating adjusting for age, marital status, income, body mass index and recent distress.

Results

Pronounced sex differences were associated with eating disorder risk (PRs 4.89–11.04; all P values < .0001). Findings of particular interest included significantly higher PRs for eating disorder risk in males associated with gambling (PR 5.07, P< .0001) and for females associated with steroid and inhalant use as well as suicide thoughts and attempts (PRs 5.40–5.48, all P values < .0001).

Discussion

The findings from this detailed exploration of sex differences and eating disorder risk among psychiatric conditions, compulsive behaviors and substance use suggest that problem gambling, the use of inhalants and steroids and suicidal ideation in relationship to eating disorder risk warrant further investigation.     

Troubles obsessionnels compulsifs résistants et antipsychotiques : données neurobiologiques et thérapeutiques actuelles

Introduction

Forty to sixty percent of patients with obsessive compulsive disorder (OCD) are resistant to well conducted treatment with selective serotonin reuptake inhibitors (SSRIs) over 8 weeks. The data concerning effectiveness of the addition of antipsychotics in this indication is controversial.

Aims of the study

To synthesize the neurobiological mechanisms at work in order to understand the action of pharmacological treatments in this disease and to propose a systematic review of the literature on effectiveness of different antipsychotic drugs according to their pharmacological profiles, in monotherapy or in combination with SSRIs in OCD.

Method

We conducted a systematic review of the literature using the criteria according to the PRISMA research paradigm “obsessive compulsive disorder AND antipsychotic agents”. Research bases MEDLINE, Cochrane and Web of science have been explored.

Results

Unlike the classical serotonergic hypothesis, OCD may result from striatal dopaminergic hyperactivity, modulated in some patients by an underlying serotonergic hypoactivity. Most studies report effectiveness of first-generation antipsychotics (amisulpride and haloperidol) and some second-generation antipsychotics (risperidone, olanzapine, aripiprazole, quetiapine) in combination with an SSRI in the treatment of resistant OCD. Recrudescence or onset of OCD in patients with schizophrenia have been described in a relay from first generation antipsychotic to olanzapine, risperidone, aripiprazole or clozapine in case reports, but not amisulpride and quetiapine.     

Escitalopram-induced Parkinsonism

Objective

Since the early reports associating extrapyramidal side effects (EPS) to serotonin reuptake inhibitors (SSRI), SSRIs have been pointed as more common offenders among antidepressants in producing EPS. The induction of EPS by SSRIs has been thought to be a consequence of serotonergically mediated inhibition of the dopaminergic system. We would like to present a case of escitalopram-induced Parkinsonism to increase awareness of this clinical problem.

Method

A 29-year-old male patient complaining of anger outbursts was started on escitalopram 10 mg/day without titration for impulse control in an outpatient clinic. Personal and family history was not significant for any chronic disorder, including movement disorders.

Results

Two weeks after the initiation of escitalopram, the patient started complaining of tremor, rigidity, slowness of movement, use of small steps when walking difficulty to rise when seated, disturbance of speech and along with the development of a mask-like facial expression. An MRI of the brain revealed normal findings. With a diagnosis of drug-induced Parkinsonism, he was started on 4-mg/day biperiden leading to full resolution of symptoms in 4 weeks, with no further complaints at follow up for 1.5 years.

Conclusion

As described, drug-induced Parkinsonism may persist or remit slowly despite prompt discontinuation of the offending drug. Some patients may require medications temporarily to relieve symptoms.     

Evaluating the CANSAS self-report (CANSAS-P) as a screening instrument for care needs in people with psychotic and affective disorders

The metabolic profiles of Chinese patients treated with second-generation antipsychotic (SGA) medication and first-generation antipsychotic (FGA) medication were compared. The sample comprised 99 patients treated with SGA (risperidone, olanzapine and ziprasidone) and 99 with FGA (chlorpromazine, haloperidol and trifluoperazine) from the outpatient clinic of a teaching hospital in Hong Kong. The most frequent psychiatric diagnosis was schizophrenia, followed by affective disorder and other psychiatric diagnoses. Subjects were measured for body weight, body height, fasting lipid and glucose levels. SGA was associated with higher LDL-cholesterol level than FGA. Individual comparison of different antipsychotics showed that patients on olanzapine had the greatest increases in cholesterol and triglycerides among all antipsychotics. The finding suggested SGA, particularly olanzapine, were associated with more metabolic risk factors than first-generation antipsychotics.     

Anger with murderous impulse induced by lamotrigine

Objective

To report two cases of major depressive disorder in which lamotrigine (LTG) induced anger with murderous impulse.

Patients

Case 1 was a 22-year-old man with symptoms of obsessive–compulsive disorder who developed major depressive disorder with antidepressant-induced hypomanic episodes. Case 2 was a 23-year-old woman experiencing an antidepressant-refractory depressive episode for whom remission was achieved by switching to a mood stabilizer and antipsychotics. In both cases LTG was started to treat the depressive episode.

Results

Case 1 manifested with anger and murderous impulse when taking 125 mg/day of LTG. A reduction to 75 mg/day calmed this anger. Case 2 manifested with the same symptom when taking 25 mg/day of LTG, and the symptom immediately disappeared upon stopping LTG.

Conclusions

Use of LTG for epilepsy in intellectually disabled patients was reported to be associated with onset or exacerbation of aggressive or violent behavior. The two cases would suggest that LTG may cause anger so severe as to be accompanied with murderous impulse when administered to patients with mood disorders. Physicians should be cognizant of this possible, albeit infrequent, adverse effect even in use of LTG for mood disorders.     

Manganese superoxide dismutase gene Ala-9Val polymorphism might be related to the severity of abnormal involuntary movements in Korean schizophrenic patients

Objective

This study examined whether the manganese superoxide dismutase (MnSOD) gene Ala–9Val single-nucleotide polymorphism (SNP) is associated with neuroleptic-induced tardive dyskinesia (TD) and the severity of the abnormal involuntary movements in Korean schizophrenic patients.

Method

We investigated whether the MnSOD gene Ala–9Val SNP is associated with TD in Korean schizophrenic patients with (n = 83) and without (n = 126) TD who were matched for exposure to antipsychotics and other relevant variables.

Results

Logistic regression analysis revealed that being older (p = 0.026) was a risk factor for TD, but that there was no significant association between MnSOD gene and TD. Abnormal involuntary movements were more severe in carriers of the Ala allele than in noncarriers (p = 0.044).

Conclusion

These findings do not support that the MnSOD gene Ala–9Val SNP is associated with TD in Korean schizophrenic patients. However, this polymorphism might be related to the severity of abnormal involuntary movements in this population.     

Diagnostic and psychosocial differences in psychiatrically hospitalized military service members with single versus multiple suicide attempts

Introduction

Individuals with multiple versus single suicide attempts present a more severe clinical picture and may be at greater risk for suicide. Yet group differences within military samples have been vastly understudied.

Purpose

The objective is to determine demographic, diagnostic, and psychosocial differences, based on suicide attempt status, among military inpatients admitted for suicide-related events.

Method

A retrospective chart review design was used with a total of 423 randomly selected medical records of psychiatric admissions to a military hospital from 2001 to 2006.

Results

Chi-square analyses indicated that individuals with multiple versus single suicide attempts were significantly more likely to have documented childhood sexual abuse (p =.025); problem substance use (p = .001); mood disorder diagnosis (p = .005); substance disorder diagnosis (p =.050); personality disorder not otherwise specified diagnosis (p =.018); and Axis II traits or diagnosis (p = .038) when compared to those with a single attempt history. Logistic regression analyses showed that males with multiple suicide attempts were more likely to have problem substance use (p = .005) and a mood disorder diagnosis (p =.002), while females with a multiple attempt history were more likely to have a history of childhood sexual (p =.027).

Discussion

Clinically meaningful differences among military inpatients with single versus multiple suicide attempts exist. Targeted Department of Defense suicide prevention and intervention efforts that address the unique needs of these two specific at-risk subgroups are additionally needed.     

Psychiatric and substance-use comorbidities associated with lifetime crack cocaine use in young adults in the general population

Objective

To assess the association between lifetime crack cocaine use and psychiatric (post-traumatic stress disorder, current depression, current dysthymia, generalized anxiety disorder, panic disorder with agoraphobia, social phobia, as well as SRQ scores and suicide risk) and substance-use disorders (tobacco, alcohol, cannabis, cocaine, amphetamine, inhalants, sedatives, hallucinogens and opioids) in youth in the general population of the city of Pelotas, RS.

Method

This was a cross-sectional population-based study, involving 1560 participants between 18 and 24 years old. Lifetime substance use and abuse were investigated using the ASSIST inventory. Psychiatric comorbidities were assessed using the Mini-International Neuropsychiatric Interview and symptoms of common mental disorders were evaluated with the Self-Reported Questionnaire (SRQ).

Results

The prevalence of lifetime crack cocaine use in the sample was 2.5%. Its use was associated with total SRW scores and the presence of post-traumatic stress disorder, antisocial personality disorder and suicide risk in the final regression model. Tobacco, alcohol, cannabis, cocaine, amphetamine and cocaine dependence were also associated with lifetime use of crack cocaine.

Discussion

Youth with a history of crack cocaine use had a higher prevalence of psychiatric conditions such as post-traumatic stress disorder, as well as an increased risk of tobacco, alcohol, cannabis, cocaine, amphetamine and inhalant use and dependence.     

Influence of attention-deficit/hyperactivity disorder on binge eating behaviors and psychiatric comorbidity profile of obese women

Objective

Previous studies have reported higher prevalence rates of attention-deficit/hyperactivity disorder (ADHD) both in eating disorders (ED) and in obese patients. We compared the psychiatric comorbidity profile of obese ADHD women with non-ADHD obese women and how ADHD symptoms impact in binge eating behaviors.

Design

Cross-sectional study of a clinical sample.

Subjects

171 adult women were evaluated at a specialized clinic in obesity and ED.

Measurements

Participants complete a semi-structured interview and psychopathology rating scales. A hierarchical regression model was employed to predict binge eating behavior.

Results

Obese ADHD patients had a larger number of psychiatric comorbidities (p < 0.001), especially Substance Abuse Disorders, and higher scores on psychopathology rating scales (p < 0.05). The highest prediction for binge eating in the regression model was the presence of depressive symptoms, followed by ADHD inattention symptoms and trait-impulsivity.

Conclusion

ADHD should be routinely evaluated in obese since it is related with more severe psychopathology. Depressive symptoms can predict the presence of binge eating in obese patients.     

Horizontal and vertical eye movement metrics: What is important?

Objective

To assist other eye movement investigators in the design and analysis of their studies.

Methods

We examined basic saccadic eye movements and smooth pursuit in the horizontal and vertical directions with video-oculography in a group of 145 healthy subjects between 19 and 82 years of age.

Results

Gender and education level did not influence eye movement metrics. With age, the latency of leftward and vertical pro- and antisaccades increased (p < 0.001), velocity of upward prosaccades decreased (p < 0.001), gain of rightward and upward prosaccades diminished (p < 0.001), and the error rate of antisaccades increased (p < 0.001). Prosaccades and antisaccades were influenced by the direction of the target, resulting in a right/left and up/down asymmetry. The skewness of the saccade velocity profile was stable throughout the lifespan, and within the range of saccades analyzed in the present study, correlated with amplitude and duration only for antisaccades (p < 0.001).

Conclusions

Some eye movement metrics must be separated by the direction of movement, others according to subject age, while others may be pooled.

Significance

This study provides important information for new oculomotor laboratories concerning the constitution of subject groups and the analysis of eye movement metrics.