Acquired pendular nystagmus: its characteristics, localising value and pathophysiology

Investigations were made of 16 patients with acquired pendular nystagmus and a further 32 cases reported in the literature were reviewed. Amongst our own patients two thirds had multiple sclerosis, almost one third a cerebrovascular accident or angioma and two had optic atrophy with squint. The nystagmus took forms which could be monocular or binocular, conjugate or disconjugate and could involve movements about single or multiple axes. Spectral analysis was used to characterise the amplitude and frequency of the movements and to estimate the degree of relationship (coherence) between movements of the two eyes or between movements of one eye about several axes. The oscillations ranged in frequency from 2·5 Hz to 6 Hz, with typical amplitudes between 3° and 5°. In a given patient all oscillations, regardless of plane, were highly synchronised. Somatic tremors of the upper limb, face and palate associated with the nystagmus were often at similar frequencies to the eye movement. The other ocular signs common to all our patients were the presence of squint with failure of convergence. Most patients also had skew deviation or internuclear ophthalmoplegia or both. The major oculomotor systems, that is, saccades, pursuit, optokinetic and vestibulo-ocular reflexes could be intact. It is inferred that the mechanism responsible for the pendular nystagmus lies at a level which is close to the oculomotor nuclei so that it can have monocular effects but is not part of the primary motor pathways. It is possible that this mechanism normally subserves maintenance of conjugate movement and posture of the eyes. The periodicity of the nystagmus is likely to arise from instability in a certain type(s) of neurone, for the associated somatic tremors have similar characteristics and yet involve very different neuronal muscular circuitry. Prognosis for cessation of the nystagmus is poor. In five patients with multiple sclerosis it was suppressed by intravenous hyoscine with, however, unacceptable subsequent side effects.     

Show me the child at seven: the consequences of conduct problems in childhood for psychosocial functioning in adulthood

BACKGROUND: This paper seeks to extend research into the adult sequelae of childhood conduct problems by investigating the associations between conduct problems in middle childhood and psychosocial outcomes in adulthood. METHOD: Data were gathered during the course of a 25-year longitudinal study of a birth cohort of New Zealand young people. Information was collected on: a) parent and teacher reports of child conduct problems at ages 7, 8 and 9 years; b) measures of crime, substance use, mental health, sexual/partner relationships, education/employment; c) confounding factors, including childhood, family and educational characteristics. RESULTS: There were statistically significant associations between childhood conduct problems from 7-9 years and risks of adverse outcomes across all domains of functioning. After control for confounding factors the associations between conduct problems and education/employment outcomes became statistically non-significant. Associations persisted for other outcomes (crime, substance dependence, mental health and sexual/partner relationships). Children in the most disturbed 5% of the cohort had rates of these outcomes that were between 1.5 and 19 times higher than rates for the least disturbed 50% of the cohort. The associations between conduct problems and adult outcomes were similar for males and females. CONCLUSIONS: Childhood conduct problems were associated with a wide range of adverse psychosocial outcomes (crime, substance use, mental health, sexual/partner relationships) even after control for confounding factors. The results reinforce the need for greater investment into interventions to address these problems.     

How does childhood economic disadvantage lead to crime?

BACKGROUND: This study sought to examine the associations between indices of socio-economic deprivation in childhood and later involvement in crime. METHOD: Data were gathered as part of the Christchurch Health and Development Study. In this project a cohort of 1,265 children born in Christchurch in 1977 have been studied from birth to age 21 years. The measures collected included: self-reported property and violent crime (15-16, 17-18, and 20-21 years); officially recorded convictions for property/violent crime; measures of childhood socio-economic status; and a series of intervening factors, including parenting (use of physical punishment, maternal care, family change, parental attachment, parental offending), individual (conduct and attention problems), school (truancy, suspensions, examination performance, scholastic ability), and peer factors (affiliations with deviant and substance using peers). RESULTS: The results suggest that childhood socio-economic disadvantage was associated with clear increases in rates of both self-reported crime and officially recorded convictions. However, using block recursive negative binomial regression models a range of parental, individual, school, and peer factors were found to intervene between socio-economic disadvantage and crime. Following introduction of these measures into the models, the association between socio-economic disadvantage and crime became both statistically and practically non-significant. CONCLUSIONS: This study suggests that the higher rates of crime found amongst young people from socio-economically disadvantaged families reflect a life course process in which adverse family, individual, school, and peer factors combine to increase individual susceptibility to crime.     

Asthma and depressive and anxiety disorders among young persons in the community

BACKGROUND: The objectives of the study were to examine linkages between asthma and depressive and anxiety disorders in a birth cohort of over 1000 young persons studied to the age of 21 years. Specifically, the study aimed to ascertain the extent to which associations between asthma and depressive and anxiety disorders could be explained by non-observed fixed confounding factors. METHOD: Asthma and depressive and anxiety disorders were measured prospectively over the course of a 21-year longitudinal study. Fixed effects logistic regression models were used to determine the relationship between asthma and depressive and anxiety disorders, adjusting for potentially confounding factors. RESULTS: Asthma in adolescence and young adulthood was associated with increased likelihood of major depression (OR 1.7, 95 % CI 1.3-2.3), panic attacks (OR 1.9, 95 % CI 1.3-2.8), and any anxiety disorder (OR 1.6, 95% CI 1.2-2.2). Associations between asthma and depressive and anxiety disorders were adjusted for confounding factors using a fixed effects regression model which showed that, after control for fixed confounding factors, asthma was no longer significantly related to major depression (OR 1.1), panic attacks (OR 1.1), or any anxiety disorder (OR 1.2). Additional post hoc analyses suggested that exposure to childhood adversity or unexamined familial factors may account for some of the co-morbidity of asthma and depressive and anxiety disorders. CONCLUSIONS: These results confirm and extend previous findings by documenting elevated rates of depressive and anxiety disorders among young adults with asthma, compared with their counterparts without asthma, in the community. The weight of the evidence from this study suggests that associations between asthma and depressive and anxiety symptoms may reflect effects of common factors associated with both asthma and depressive and anxiety disorders, rather than a direct causal link. Future research is needed to identify the specific factors underlying these associations.     

Can misalignments in typical infants be used as a model for infantile esotropia?

PURPOSE: To investigate the nature of early ocular misalignments in human infants to determine whether they can provide insight into the etiology of esotropia and, in particular, to examine the correlates of misalignments. METHODS: A remote haploscopic photorefraction system was used to measure accommodation and vergence in 146 infants between 0 and 12 months of age. Infants underwent photorefraction immediately after watching a target moving between two of five viewing distances (25, 33, 50, 100, and 200 cm). In some instances, infants were tested in two conditions: both eyes open and one eye occluded. The resultant data were screened for instances of large misalignments. Data were assessed to determine whether accommodative, retinal disparity, or other cues were associated with the occurrence of misalignments. RESULTS: The results showed that there was no correlation between accommodative behavior and misalignments. Infants were more likely to show misalignments when retinal disparity cues were removed through occlusion. They were also more likely to show misalignments immediately after the target moved from a near to a far position in comparison to far-to-near target movement. DISCUSSION: The data suggest that the prevalence of misalignments in infants of 2 to 3 months of age is decreased by the addition of retinal disparity cues to the stimulus. In addition, target movement away from the infant increases the prevalence of misalignments. These data are compatible with the notion that misalignment are caused by poor sensitivity to targets moving away from the infant and support the theory that some forms of strabismus could be related to failure in a system that is sensitive to the direction of motion.     

Neuroticism in adolescence and psychotic symptoms in adulthood

BACKGROUND: The aims of this research were to examine the associations between the personality trait of neuroticism in adolescence and later psychotic symptoms, taking into account potential confounding factors. METHOD: Data were gathered over the course of a longitudinal study of a birth cohort of New Zealand born young people (N=1265). Over the course of the study, data were gathered on: (a) neuroticism at age 14; (b) psychotic symptoms predominantly subclinical, assessed on the Symptom Checklist (SCL-90), at ages 18 and 21; (c) a range of potential confounding factors including measures of childhood adversity and co-morbid mental disorders. RESULTS: Young people in the highest quartile of neuroticism at age 14 had rates of psychotic symptoms that were two to three times higher than those in the lowest quartile. After statistical adjustment for confounding factors, including childhood adversity and co-morbid mental disorders, the association between neuroticism and later psychotic symptoms reduced but remained statistically significant (P<0.05). After adjustment for confounding, young people with high levels of neuroticism had rates of psychotic symptoms that were between 1.5 to 1.8 times higher than those with low levels of neuroticism. CONCLUSIONS: Early neuroticism may be a precursor to the onset of psychotic symptoms. The mechanisms underlying this association are unclear, but may relate to overlapping features between prodromal phases of psychosis and items that measure neuroticism.     

Posthaemorrhagic ventricular dilatation in the premature infant: natural history and predictors of outcome

OBJECTIVE: To investigate the natural history and predictors of outcome of posthaemorrhagic ventriculomegaly in the very low birthweight (VLBW) infant. METHODS: All VLBW infants admitted between September 1994 and September 1997 to the neonatal intensive care units of Brigham and Women's Hospital (Boston), Children's Hospital (Boston), and Christchurch Women's Hospital (New Zealand) with germinal matrix intraventricular haemorrhage (IVH) were identified. All charts and ultrasound scans were reviewed to define the natural history and perinatal and/or postnatal factors of value in prediction of the course of posthaemorrhagic ventriculomegaly. Progressive ventricular dilatation (PVD) was defined from the results of serial cranial ultrasound scans. RESULTS: A total of 248 VLBW infants had evidence of IVH (22% of all VLBW infants, mean (SD) gestational age 26.8 (2.6) weeks). A quarter of the infants exhibited PVD. Spontaneous arrest of PVD occurred without treatment in 38% of infants with PVD. Of the remaining 62% with persistent PVD, 48% received non-surgical treatment only (pharmacological and/or drainage of cerebrospinal fluid by serial lumbar punctures), 34% received surgical treatment with insertion of a ventriculoperitoneal reservoir and/or shunt, and 18% died. The development of PVD after IVH and adverse short term outcome, such as the requirement for surgery, were predicted most strongly by the severity of IVH. CONCLUSIONS: These data reflect the natural history of PVD in the 1990s and show that, despite a slight reduction in its overall incidence, there appears to be a more aggressive course, with appreciable mortality and morbidity in the extremely premature infant. The major predictor of adverse short term outcome, defined as death or need for surgical intervention, was the severity of IVH. These findings may be valuable for the management of very small premature infants.     

Too much or too little: neonatal ocular misalignment frequency can predict later abnormality

BACKGROUND: 214 orthoptists' infants have been followed for up to 15 years, relating neonatal misalignment (NMs) and first convergence onset to later childhood ocular abnormalities. NMs are shown in a companion paper to reflect the onset of first convergence, but if frequent or absent may predict a higher risk of refractive error and esodeviation. METHODS: In a prospective postal survey, orthoptist mothers observed their own infants during the first months of life and regularly reported ocular behaviour and alignment, visual development, and any subsequent ocular abnormalities. RESULTS: Later strabismus and refractive error were less common in infants who showed NMs occasionally compared with those who never or frequently did. There was a significant linear trend for fewer ocular abnormalities to be found in children with more frequent NMs (p<0.001). Hypermetropes were later to show first convergence than emmetropes or myopes (p = 0.006) CONCLUSIONS: NMs usually reflect an emerging and normally developing vergence system. This study suggests that delayed onset of convergence (and lack of NMs) is associated with later defects, especially hyperopia. Possible causal relations are discussed.     

Neonatal ocular misalignments reflect vergence development but rarely become esotropia

BACKGROUND: 214 orthoptists' infants have been followed for up to 15 years, relating neonatal misalignment (NMs) behaviour to onset of convergence and 20 Delta base out prism response, and also to later childhood ocular abnormalities. METHODS: In a prospective postal survey, orthoptist mothers observed their own infants during the first months of life and regularly reported ocular behaviour and alignment, visual development, and any subsequent ocular abnormalities. RESULTS: Results confirm previously reported characteristics of NMs. Infants who were misaligned more frequently were misaligned for longer periods (p <0.01) and were later to achieve constant alignment (p <0.001) but were earlier to attempt first convergence (p = 0.03). Maximum NM frequency was usually found at or before the onset of first convergence (p = 0.0002). CONCLUSIONS: NMs occur in the first 2 months of life and usually reflect a normally developing vergence system. They appear to represent early attempts at convergence to near targets. Emerging infantile esotropia is indistinguishable from frequent NMs before 2 months.     

Dietary fat, body weight, and cancer: contributions of studies in rodents to understanding these cancer risk factors in humans

Understanding diet and energy balance as risk factors for breast, colon, and other cancers requires information on the contribution of each factor and of interactions among factors to cancer risk. Rodent models for breast cancer provide extensive data on effects of dietary fat and calories, energy balance, body weight gain, and physical activity on tumor development. Analyses of the combined data from many studies have shown clearly that quality and quantity of dietary fat and energy balance contribute independently to increased mammary gland tumorigenesis. These findings were seen in female rats fed diets high in fat (35-40% of calories) compared to rats fed control diets, with approximately 10% of calories as fat (Fay and Freedman, 1997, Breast Cancer Res. Treat. 46, 215-223). The methods used permit comparison of experimental and epidemiological data, and they may be useful in extrapolating between species and developing public health recommendations. In addition to the contributions of lifetime-diet composition, intake, energy balance, and physical activity to cancer risk, there are questions about the timing and duration of alterations in these factors and about the "dose-response" characteristics of cancer risk to the factors. Endocrine mechanisms may be significant in mammary gland tumor risk, but experimental and epidemiological data indicate that cancers at other sites, such as colon and liver, also are influenced by the factors listed. Other diet and lifestyle factors that influence energy, or specifically fat, metabolism may also affect risk for cancers that are promoted by increased intake of fat and calories. Studies of separate and interactive effects of dietary fat, black tea, weight gain, and mammary gland tumorigenesis (Rogers, et al, 1998, Carcinogenesis 19, 1269-1273) have been analyzed. Using adjustment of carcinogenesis endpoints for body weight, tumor burden, and latency, they were found to be related to weight gain within treatment groups in 2 of 3 experiments.