Early detection of minor neurodevelopmental dysfunctions at age 6 months in prematurely born neonates

OBJECTIVE

To investigate the 6-month neurodevelopmental outcomes of prematurely born neonates and find the determining neonatal factors of minor neurological dysfunctions (MNDs).

STUDY DESIGN

We examined data collected prospectively on 151 infants born before 37th week of gestation in 2009-2010 who were assessed at 6 months corrected age with the Bayley Scales of Infant Development-2nd Edition (BSID-II) and the Denver Developmental Screening Test (DDST).

RESULTS

Of 151 neonates born before 37 weeks, 20 (13.2%) had MNDs at 6 months corrected age. These proportions were 21.6%, 13.2%, and 8.2% for neonates born before 28 weeks, 29 weeks to 32 weeks, and 33 weeks to 36 weeks, respectively. Half of neonates with MNDs have a birth body weight of less than 1000g. BSID-II and DDST are highly correlated in assessing the MNDs of premature neonates at 6 months corrected age. MND was independently associated with postnatal corticosteroid use (odds ratio [OR], 11.2; 95% confidence interval [CI], 1.9-66.0, P=0.008) and cholestasis (OR, 6.2; 95% CI, 1.16-33.1, P=0.033).

CONCLUSIONS

Premature neonates, even those born at 33 to 36 weeks, are found to have MNDs as early as 6 months corrected age by BSID-II and DDST, with risk increasing as gestation decreases.

Monoamine neurotransmitter deficiencies

Pediatric neurotransmitter disorders refer to a constellation of inherited neurometabolic syndromes attributable to disturbances of neurotransmitter synthesis, degradation, or transport. Monoamine deficiencies represent defects in synthesis of dopamine, serotonin, norepinephrine, and epinephrine or in availability of tetrahydrobiopterin, an important cofactor for monoamine synthesis. Some disorders do not manifest peripheral hyperphenyalaninemia and require CSF neurotransmitter metabolite assay for diagnosis. These include Segawa dopa-responsive dystonia and enzymatic deficiencies of aromatic amino acid decarboxylase, tyrosine hydroxylase, and sepiapterin reductase. The first, autosomal dominantly inherited GTP cyclohydrolase deficiency, has a satisfying response to therapy at any age with benefits maintained over time. The others have more severe and treatment-refractory phenotypes, typically with manifestations well beyond movement disorders. Disorders detectable by elevated serum phenylalanine are deficiencies of GTP cyclohydrolase (homozygous), pterin-carbinolamine dehydratase, dihydropteridine reductase, and pyruvoyl-tetrahydropterin synthase. The latter is the most prevalent and heterogeneous but typically has infantile onset with extrapyramidal as well as bulbar, hypothalamic, limbic, and epileptic manifestations. There are therapeutic roles for neurotransmitter supplementation, and dopaminergic agonists. Basal ganglia calcifications in dihydropteridine reductase deficiency are reversible with folinic acid. Deficiencies of monoamine degradation lead to cognitive, behavioral, and autonomic disorders.

[The clinical and electroencephalographic characteristics of early myoclonic encephalopathy]

OBJECTIVE

To investigate the clinical and electroencephalographic (EEG) characteristics, therapeutic response and long-term prognosis of early myoclonic encephalopathy.

METHOD

The clinical and EEG data of three patients with early myoclonic encephalopathy were analyzed. These patients were admitted to our hospital between September 2008 and January 2012. The patients were followed up for therapeutic response and long-term prognosis.

RESULT

The age of onset was from 2 to 23 days after birth. All patients had the onset of erratic or fragmentary myoclonus. Two patients had frequent simple focal seizures. One patient had tonic spasms when he was 3 months old. The EEG characteristic of all patients was repetitive suppression-burst pattern. The suppression-burst pattern was characterized by paroxysmal short bursts and long periods of suppression. The EEG paroxysms of one patient was asynchronous over both hemispheres. There is no effective therapy for early myoclonic encephalopathy. A patient died before two years of age. Two patients had severe partial epilepsy and showed very severe retardation.

CONCLUSION

Early myoclonic encephalopathy usually starts in the first month of life. Erratic myoclonus appears first. Myoclonus is the principal features of early myoclonic encephalopathy. Frequent focal seizures occur shortly after erratic myoclonus. Tonic epileptic spasms may develop within 3 - 5 months. The suppression-burst pattern is EEG characteristic. There is no effective therapy for early myoclonic encephalopathy and the prognosis is poor.

[Risk assessment of pre-term infants]

Pre-term birth occurs when a baby is born before 37 weeks of gestation are completed. Many recent publications on neurodevelopmental and somatic outcome parameters of premature infants are of interest for insurance medicine. Infants born before the 28th week are called extremely pre-term. When examined at five years, 85% had already received or still needed special treatment or support. The results of examinations in early childhood have quite a low predictive value for the further development of the child. In the very and moderately pre-term stages, long-term risks are continuously declining with the length of gravidity. Even "late pre-term" birth (34 to 36 weeks of gestation) is associated with a nearly doubled rate of developmental impairment and chronic disease in childhood and adolescence. Various studies performed in early adulthood showed that former pre-term infants suffered more often from asthma and psychiatric disorders. On average, they also had higher blood pressure, lower insulin sensitivity, and a reduced exercise capacity. It remains to be evaluated how much these risk factors contribute to cardiovascular or pulmonary morbidity and mortality later in life. At least, general mortality after preterm birth seems to be increased up to the oldest age group statistically evaluated up to now, i.e. 18 to 36 years.

Matching accuracy in hemiparetic cerebral palsy during unimanual and bimanual movements with (mirror) visual feedback

In the present study participants with Spastic Hemiparetic Cerebral Palsy (SHCP) were asked to match the position of a target either with the impaired arm only (unimanual condition) or with both arms at the same time (bimanual condition). The target was placed at 4 different locations scaled to the individual maximum reaching distance. To test the effect of mirror visual feedback of the less-impaired arm on the matching accuracy, an opaque screen or a mirror was placed in between the arms which masked vision of the impaired arm. Absolute endpoint error was smaller in the bimanual condition compared to the unimanual condition, but there was no effect of mirror visual feedback. Inspection of the individual data, however, showed that 13 out of 23 participants did experience a positive effect of mirror visual feedback. A positive correlation between the baseline error (screen) and the improvement in accuracy with mirror visual feedback seems to suggest that individuals with lower proprioceptive accuracy in the baseline condition may benefit more from mirror visual feedback. Together these findings indicate that bimanual therapy and therapy with mirror visual feedback might be valuable approaches for rehabilitation for a subset of the individuals with SHCP.

Promoting adaptive behavior in persons with acquired brain injury, extensive motor and communication disabilities, and consciousness disorders

These two studies extended the evidence on the use of technology-based intervention packages to promote adaptive behavior in persons with acquired brain injury and multiple disabilities. Study I involved five participants in a minimally conscious state who were provided with intervention packages based on specific arrangements of optic, tilt, or pressure microswitches (linked to preferred environmental stimuli) and eyelid, toe and finger responses. Study II involved three participants who were emerging from a minimally conscious state and were provided with intervention packages based on computer presentations of stimulus options (i.e., preferred stimuli, functional caregiver's procedures, and non-preferred stimuli) and pressure microswitches to choose among them. Intervention data of Study I showed that the participants acquired relatively high levels of microswitch responding (thus engaging widely with preferred environmental stimuli) and kept that responding consistent except for one case. Intervention data of Study II showed that the participants were active in choosing among preferred stimuli and positive caregivers' procedures, but generally abstained from non-preferred stimuli. The results were discussed in terms of the successful use of fairly new/infrequent microswitch-response arrangements (Study I) and the profitable inclusion of functional caregiver's procedures among the options available to choice (Study II).

Relationships between task-oriented postural control and motor ability in children and adolescents with Down syndrome

Individuals with Down syndrome (DS) have been characterized by greater postural sway in quiet stance and insufficient motor ability. However, there is a lack of studies to explore the properties of dynamic postural sway, especially under conditions of task-oriented movement. The purpose of this study was to investigate the relationships between task-oriented postural control and motor ability in children and adolescents with DS. The participants were 23 children and adolescents with DS (DS group, M±SD age, 14.4±2.8 years) and 18 age- and gender-matched peers (M±SD age, 13.8±3.6 years). A force plate was used to collect postural data represented by center of pressure (COP) parameters. Postural measurements were conducted for both groups in quiet standing with eyes open and with eyes closed, and also while throwing a ball at erect standing. Assessments of motor ability were only applied to the DS group by using two dimensions of the original version of Gross Motor Function Measure and 4 subtests of the Bruininks Oseretsky Test of Motor Proficiency, second edition. The results showed that while the participants with DS showed greater displacement and higher velocity of COP sways at quiet standing, they exhibited smaller COP displacement in anterior/posterior direction during throwing the ball. Three areas of motor ability, including standing motor skills, walk/run/jump motor skills and muscle strength, were found to make a significant contribution to the displacement and velocity of postural sway during the voluntary movement. It is suggested that future research should focus on investigating the definite underlying mechanism of postural sway during movement and the influence of increasing motor ability on the reactive postural sway in this population.

Mild fumarase deficiency and a trial of low protein diet

We report clinical findings in a 12-year-old girl with a mild case of fumarase deficiency who continues to make progress. She has two novel mutations of the fumarase gene [c.521C>G (p.P174R) and c.908T>C (p.L303S)]. A trial of low protein diet did not reduce fumaric aciduria.

Central processing energetic factors mediate impaired motor control in ADHD combined subtype but not in ADHD inattentive subtype

Participants with attention-deficit/hyperactivity disorder (ADHD) are often impaired in visuomotor tasks. However, little is known about the contribution of modal impairment in motor function relative to central processing deficits or whether different processes underlie the impairment in ADHD combined (ADHD-C) versus ADHD inattentive (ADHD-I) subtype. The present study analyzes performance on the Visual Motor Integration Test relative to less effortful motor tests as well as on measures of energetics. Both ADHD groups showed evidence of impaired motor function on both visual-motor integration (VMI) and the less effortful motor tests. The ADHD-C group performed below the ADHD-I group on VMI, but their performance correlated highly with the measures of the energetic pools of arousal and effort. Different mechanisms may underlie impaired fine motor skills in ADHD. Central processing deficits contribute significantly to the deficit of ADHD-C but do not explain the motor impairment in ADHD-I.

Fetal habituation in assisted conception

BACKGROUND

Neurodevelopment outcomes of children conceived by Assisted Reproductive Technology (ART)have been the subject of much recent attention. To date there are no reports of neurodevelopmental performance before birth in this group.

AIMS

To compare habituation (a measure of brain function) in fetuses conceived by assisted reproduction techniques (ART) with naturally conceived (NC) fetuses.

STUDY DESIGN

Case control study.

SUBJECTS

Women with singleton pregnancies matched for maternal age, parity and smoking were recruited in 2 groups: ART (n=20) and NC (n=20).

OUTCOME MEASURES

Sound stimuli (250 Hz, 110 dB) at 10 second intervals lasting 2 s were administered to the fetus. The end point was habituation (cessation of movement for five consecutive stimuli) or a maximum of 30 stimuli. Responses of the fetus were observed with ultrasound at 28, 32 and 36 weeks' gestation, video-recorded and anonymised for analysis.

RESULTS

At 28 weeks' gestation significantly more ART fetuses responded to sound of 250 Hz, 110 dB (p=0.02) but this difference did not persist at 32 and 36 weeks'. There was a significant increase in nonresponders as gestation advanced in the ART group. There was no difference in habituation or mean number of trials to habituate at all three gestations.

CONCLUSIONS

ART fetuses demonstrated no differences in habituation suggesting that there is no neurodevelopment delay. However, a decrease in response to sound as gestation advances might be a harbinger for poor perinatal outcomes and needs exploration.

A Danish reference chart for assessment of psychomotor development based on the Ages & Stages Questionnaire

INTRODUCTION

The aim of this study was to obtain Ages and Stages Questionnaire (ASQ) scores from the background population so that these may be used as a reference group to extremely preterm children at nine and 18 months of corrected age.

MATERIAL AND METHODS

A total of 298 children were randomly chosen among the Danish population in three different groups: 9-, 18- and 21 month-old children. The parents received the 10-month ASQ when their child had reached a corrected age of nine months and the 24-month ASQ questionnaire when their child had reached the corrected age of 18 or 21 months.

RESULTS

The total scores were normally distributed in both groups. There was a highly significant (p < 0.001) linear regression between ASQ total score and adjusted age for both the 10- and the 24-month ASQ.

CONCLUSION

The results of the study show that the overall development can be assessed when the child is scored with an ASQ intended for older children. Screening for developmental delay in children in the age range of 8-10 months or 18-22 can be quickly assessed by reference to a chart. The chart can also be used as a reference when monitoring the quality in neonatal services by the developmental outcome and this ensures that children are classified according to Danish standards.

Bowen-Conradi: a common Hutterite condition that mimics trisomy 18

Bowen-Conradi syndrome (BCS) is a lethal autosomal recessive condition having significant clinical overlap with trisomy 18. Though rare in the general population, it is quite common in the Hutterites of the United States and Canada. The carrier frequency in the Hutterite population is estimated to be one in 10, making BCS one of the most commonly inherited genetic diseases in any human group studied to date. We describe two infant patients who were initially thought to have trisomy 18, but for whom chromosome studies were normal. Additionally, we briefly review the historical background of the Anabaptist Hutterite populations in South Dakota, compare the clinical findings in BCS and trisomy 18 and discuss the importance of genetic counseling for couples of Hutterite descent.

The effect of institutionalization on psychomotor development of preschool aged children

Development can be altered by several factors which can either facilitate or obstruct development. The aim of the current study was the examination and the detection of differences in the developmental profiles of preschool aged children living in conventional institution facilities (N=28), in SOS villages (N=20) and in natural family environment (N=48). The psychomotor development of the 96 children, aged 4-6 years old, was assessed using the six scales of the Griffiths Test No II. Two-way analysis of variance designs showed that family reared children had better performance in all scales of the Griffiths test compared with children of the other two groups and that children living in a SOS village had better scores on all domains of development examined compared to children living in a conventional institution (p<.05). The findings reinforce the need to transform institution environments into more supportive ones for the most benefit of children's development and mental health.

Patterns of participation and enjoyment in adolescents with Down syndrome

This study aimed to determine participation and enjoyment in young people with Down syndrome (DS) in Taiwan and to assess how participation varies across gender, cognitive, and motor function variables. Using the Children's Assessment of Participation and Enjoyment, data on participation were collected from 997 adolescents with DS and their families. Findings indicated limited diversity and intensity of participation, with proportionately greater involvement in informal activities. Youth with better cognitive and motor functions participated more often in activities and reported higher enjoyment and social engagement with these. These findings provide a foundation for an improved understanding of activity participation of youth with DS. Service providers and families could provide and plan activities to ensure more satisfying and meaningful participation.

Fitness to drive - GP perspectives of assessing older and functionally impaired patients

BACKGROUND

General practitioners have expressed concern about their ability to assess patients' driving fitness. This study explores GP perspectives regarding assessing fitness to drive in older and functionally impaired patients.

METHODS

We held face-to-face interviews with seven metropolitan GPs and a focus group with nine rural GPs. Data were analysed using thematic analysis.

RESULTS

General practitioners were unsure whether they or driving authorities should have responsibility for assessing patients' fitness to drive; recognised that driving is important for maintaining independence; described referral to an occupational therapist as useful, and expressed concern about the lack of access to alternative forms of transport and also about privacy issues. Opinion was divided about the merits of the VicRoads Medical Report Form and the usefulness of the Austroads guide.

DISCUSSION

This qualitative study suggests that some GPs may find assessing fitness to drive to be challenging and problematic in general practice. Further resources and education could assist these GPs to increase their confidence and competence in assessing a patient's fitness to drive.

[Psychomotor disadaptation syndrome: a poorly known clinical entity]

Psychomotor disadaptation syndrome is a typical geriatric clinical syndrome. It includes postural disorders such as body retropulsion, specific gait disorders, with axial akinesia and hypertonia, and psychobehavioral disorders akin to those found in depression. The diagnosis is essentially based on clinical observation rather than on iconographic data. This syndrome causes falls which induce a fear of falling. The old patient has a tendency to put himself down, to withdraw from society and to lose autonomy. This article briefly describes the physiopathology of the syndrome, recalls the diagnostic tools, and makes some suggestions regarding the care of patients suffering from this clinical entity.

Experimental approaches to study functional recovery following cerebral ischemia

Valid experimental models and behavioral tests are indispensable for the development of therapies for stroke. The translational failure with neuroprotective drugs has forced us to look for alternative approaches. Restorative therapies aiming to facilitate the recovery process by pharmacotherapy or cell-based therapy have emerged as promising options. Here we describe the most common stroke models used in cell-based therapy studies with particular emphasis on their inherent complications, which may affect behavioral outcome. Loss of body weight, stress, hyperthermia, immunodepression, and infections particularly after severe transient middle cerebral artery occlusion (filament model) are recognized as possible confounders to impair performance in certain behavioral tasks and bias the treatment effects. Inherent limitations of stroke models should be carefully considered when planning experiments to ensure translation of behavioral data to the clinic.

[Visual-spatial functions and organisation of grapho-motor actions in ADHD children]

AIM

The aim of the study was to test whether children with a diagnosis of ADHD at the age of 7-16 years have deficits in visual-spatial, visual memory, planning, and organisation of the visual-motor functions.

METHODS

The study included 186 unrelated patients aged 7-16 years diagnosed with ADHD. The control group consisted of 156 healthy individuals aged 7-16 years. The methods applied were the Rey-Osterrieth Complex Figure Test (ROCF) and Matching (MFFT).

RESULTS

The number of errors in the MFFT was significantly different between healthy combined subtype. There were no differences between inattentive and healthy children. In the Rey-Osterieth Complex Figure test, statistically significant differences were found between the control group and a group of combined ADHD in the number of points obtained when drawing back and reproduction from memory. In the latter index were also differences between ADHD inattentive children and the combined subtype. Children with ADHD obtained statistically significant different results than healthy children in the drawing category (which were treated as an indicator of the executive functions of planning) but only in reproduction from memory. Quality of the copy does not differentiate the groups.

CONCLUSIONS

ROCF and MFFT are useful measures of visual-spatial function and visual memory of children with ADHD. They have less relevance in the assessment of executive functions. Visual-spatial disorders were found only in children with ADHD combined subtype.

Reliability and validity of age band 1 of the Movement Assessment Battery for Children--second edition

The purpose of this study was to examine specific aspects of the reliability and validity of age band 1 of the Movement Assessment Battery for Children--Second Edition (MABC-2) (Henderson, Sugden, & Barnett, 2007) in Greek preschool children. One hundred and eighty-three children participated in the study; the children ranged in age from 36 to 64 months old (M = 50 months, SD = 9 months). Test-retest reliability of the MABC-2 was evaluated using intraclass correlation coefficient (ICC). Cronbach's alpha for the items of each motor domain was estimated to determine internal consistency. Confirmatory factor analysis was used to examine the factorial validity of the MABC-2 test. Correlation coefficients among individual item scores and the total score were also calculated to further examine validity. The ICC for all test items was good, except for the drawing trail task, which was moderate. Cronbach's alpha coefficient values were .51, .70 and .66 for manual dexterity, aiming and catching, and balance, respectively. In the confirmatory factor analysis, goodness-of-fit indices suggested a satisfactory fit of the data to the model. The correlation coefficients between each test item and the total score were moderate. The results suggest that the MABC-2 can be a reliable and valid tool for the assessment of movement difficulties among 3-5-year-old children.

Psychomotor retardation in depression: biological underpinnings, measurement, and treatment

Psychomotor retardation is a long established component of depression that can have significant clinical and therapeutic implications for treatment. Due to its negative impact on overall function in depressed patients, we review its biological correlates, optimal methods of measurement, and relevance in the context of therapeutic interventions. The aim of the paper is to provide a synthesis of the literature on psychomotor retardation in depression with the goal of enhanced awareness for clinicians and researchers. Increased knowledge and understanding of psychomotor retardation in major depressive disorder may lead to further research and better informed diagnosis in regards to psychomotor retardation. Manifestations of psychomotor retardation include slowed speech, decreased movement, and impaired cognitive function. It is common in patients with melancholic depression and those with psychotic features. Biological correlates may include abnormalities in the basal ganglia and dopaminergic pathways. Neurophysiologic tools such as neuroimaging and transcranial magnetic stimulation may play a role in the study of this symptom in the future. At present, there are three objective scales to evaluate psychomotor retardation severity. Studies examining the impact of psychomotor retardation on clinical outcome have found differential results. However, available evidence suggests that depressed patients with psychomotor retardation may respond well to electroconvulsive therapy (ECT). Current literature regarding antidepressants is inconclusive, though tricyclic antidepressants may be considered for treatment of patients with psychomotor retardation. Future work examining this objective aspect of major depressive disorder (MDD) is essential. This could further elucidate the biological underpinnings of depression and optimize its treatment.

Psychogenic movement disorders and motor conversion: a roadmap for collaboration between neurology and psychiatry

BACKGROUND

There are a host of vague terms to describe psychologically-mediated symptoms that mimic neurological disease, such as "functional," "non-organic," "psychogenic," or "medically unexplained." None of these terms has a direct translation in psychiatric classification, and psychiatrists are often faced with patients who do not believe in a psychological origin for their symptoms.

OBJECTIVE

Within the framework of psychogenic movement disorders, we discuss the roadblocks to effective collaboration and treatment in these patients and the current state of the literature regarding diagnosis and treatment.

RESULTS

We describe the approach to these patients from the perspective of neurology and psychiatry, illustrating the differences in terminology and categorization.

CONCLUSION

Psychogenic movement disorders represent a unique opportunity for these fields to collaborate in the care of a potentially curable but significantly disabling disorder.

[The inter-rater reliability of the Dutch version of the core. A validation study conducted among depressed elderly in-patients]

BACKGROUND

Assessment of psychomotor symptoms may lead to better classification of depressive disorders.

AIM

To test the inter-rater reliability of the Dutch version of CORE, an observational instrument for psychomotor symptoms.

METHOD

The CORE was used with 37 depressed in-patients and was scored by 5 psychiatrists. Intra-class correlation (ICCagreement) was tested.

RESULTS

ICCagreement of the total score (0.80), and the subscales non-interaction (0.74), retardation (0.70) and agitation (0.79) were sufficient.

CONCLUSION

The Dutch version of the CORE is a reliable instrument.

Adenylosuccinate lyase deficiency in a Malaysian patient, with novel adenylosuccinate lyase gene mutations

Most cases of adenylosuccinate lyase (ADSL OMIM 103050) deficiency reported to date are confined to the various European ethnic groups. We report on the first Malaysian case of ADSL deficiency, which appears also to be the first reported Asian case. The case was diagnosed among a cohort of 450 patients with clinical features of psychomotor retardation, global developmental delay, seizures, microcephaly and/or autistic behaviour. The patient presented with frequent convulsions and severe myoclonic jerk within the first few days of life and severe psychomotor retardation. The high performance liquid chromatography (HPLC) profile of the urine revealed the characteristic biochemical markers of succinyladenosine (S-Ado) and succinyl-aminoimidazole carboximide riboside (SAICAr). The urinary S-Ado/SAICAr ratio was found to be 1.02 (type I ADSL deficiency). The patient was compound heterozygous for two novel mutations, c.445C > G (p.R149G) and c.774_778insG (p.A260GfsX24).

Reduced cognitive and psychomotor impairment with extended-release oxymorphone versus controlled-release oxycodone

BACKGROUND

Opioids provide effective pain control, yet have risks including adverse events (AEs) (e.g., constipation, nausea/vomiting, sedation) and cognitive/psychomotor effects.

OBJECTIVE

To compare cognitive and psychomotor effects of oxymorphone extended release (OM-ER) versus oxycodone controlled release (OC-CR).

STUDY DESIGN

Randomized, double-blind, 5-way crossover

SETTING

Single inpatient research unit

METHODS

Nondependent recreational opioid users were administered single intact oral tablets of placebo, OM-ER (15 and 30 mg), and OC-CR (30 and 60 mg), separated by a 7- to 21-day washout. The divided attention (DA) test measured psychomotor impairment (e.g., manual tracking [e.g., percentage over road], target accuracy [e.g., target hits], reaction time [hit latency]). Visual analog scales measured alertness/drowsiness, agitation/relaxation, and dizziness. Sedative, stimulant, and dysphoric effects were measured using the Addiction Research Center Inventory Pentobarbital-Chlorpromazine-Alcohol (PCAG), Benzedrine Group (BG), and Lysergic Acid Diethylamide (LSD) scales, respectively. Comparisons were made between equianalgesic doses (OM-ER 15 mg vs OC-CR 30 mg; OM-ER 30 mg vs OC-CR 60 mg), within active drug doses, and between active drugs and placebo using least squares (LS) mean difference of the peak maximum (Emax) or minimum (Emin) effect using linear mixed model analysis of covariance.

RESULTS

Thirty-five participants received all 5 treatments. Peak cognitive and psychomotor impairment (LS mean [SE]) was less with OM-ER than equianalgesic doses of OC-CR for reaction time (Emax hit latency, longer if impaired; 571.2 [13.4] vs 588.1 ms [13.4], P=0.03 for OM-ER 15 mg vs OC-CR 30 mg, respectively; 572.4 [13.4] vs 604.3 ms [13.4], P=0.03 for OM-ER 15 mg vs OC-CR 30 mg, respectively; 572.4 [13.4] vs 604.3 ms [13.4], P<0.001 for OM-ER 30 mg vs OC-CR 60 mg, respectively); tracking accuracy (Emin percentage over road, lower if impaired; 71.4 [2.4] vs 65.3 [2.4], P=0.007; 69.9 [2.4] vs 59.4 [2.4], P<0.001), and target accuracy (Emin target hits percentage, lower if impaired; 81.0 [3.1] vs 74.5 [3.1], P=0.02; 79.4 [3.1] vs 66.1 [3.1], P<0.001). Several other DA measures showed that OC-CR, especially 60 mg, produced more psychomotor impairment than equianalgesic OM-ER. Compared to OM-ER, OC-CR produced more dizziness (Emax, P<0.001 for OM-ER 15 mg vs OC-CR 30 mg and for OM-ER 30 mg vs OC-CR 60 mg), drowsiness (Emax, P<0.001 for both equianalgesic dose groups), relaxation (Emin, P=0.003 for OM-ER 15 mg vs OC-CR 30 mg; P=0.001 for OM-ER 30 mg vs OC-CR 60 mg), dysphoria (Emax LSD, P<0.001 for both equianalgesic dose groups), and sedation (Emax, PCAG; P<0.001 for both equianalgesic dose groups) and less stimulation (BG, Emin; P=0.01 for OM-ER 15 mg vs OC-CR mg; P<0.001 for OM-ER 30 mg vs OC-CR 60 mg). Several AEs occurred more commonly with OC-CR than OM-ER (e.g., euphoria, nausea, somnolence, vomiting, dizziness).

LIMITATIONS

Participants were young, healthy volunteer nondependent recreational drug users, and only single doses were evaluated. The effects of tampering or higher doses were not assessed.

CONCLUSION

Single oral intact low and high doses of OM-ER produced less cognitive and psychomotor impairment plus less sedation than equianalgesic OC-CR in this exploratory study. ClinicalTrials.gov registration NCT00955110.