Psychiatric complications of homozygous sickle cell disease among young adults in the Jamaican Cohort Study

BACKGROUND: This study aimed to determine the prevalence of psychiatric disorder in young adults with homzygous sickle cell (SS) disease and in contols with normal haemoglobin, and to examine factors associated with psychiatric disorder. METHOD: The study design was cross-sectional. Subjects were aged 18-20 years: 63 with SS disease and 89 controls. The Psychiatric Assessment Schedule was used to determine psychiatric disorder at index of definition level 5. RESULTS: Psychiatric disorder was identified in 18 (29 percent) SS disease patient and in 22 (25 percent) control. In SS patients, psychiatric disorder was not related to illness severity but was associated with leaving school early, difficulties in social adjustment, impaired cognitive function and having previous psychiatric difficulties. Male SS patients with psychiatric disorder all had low body mass index (BMI < 17.60). In controls, psychiatric disorder was associated with female gender, unemployment and difficulties in social adjustment. CONCLUSION: The prevalence of psychiatric disorder was similar in patients and controls, although associated factors tended to be different. The association with low BMI in SS men merits further study.(AU)

Factors associated with lowered intelligence in homozygous sickle cell disease

The intelligence quotient (IQ) of 60 patients with homozygous sickle cell (SS) disease and 60 age and sex matched controls with a normal haemoglobin (AA) genotype aged 15-18 years, followed up in a cohort study from birth, was assessed by the Wechsler intelligence scales for children and adults. IQ appeared to be normally distributed in both genotypes but mean values in SS disease were 5.6 points (95 percent confidence interval (CI) 1.0 to 10.2) lower than in AA controls (p=0.016). THe difference occurred in both verbal (5.5 points, p=0.017) and performance (5.0 points, p=0.044) subscales of the IQ defect in SS disease was associated with a significantly lower attention factor score (p=0.005) but not with other factor scores. The genotype difference in IQ was not accounted for by differences in parental occupational level, school absenteeism, or school drop out, or reported activity level. In SS disease, IQ was not related to mean steady state haemoglobin, or mean cell haemoglobin concentration, or clinical severity as judged by the frequency of painful crises, hospital admission, or sick visits. IQ, at age 15-18 years, correlated with the patients' height at all ages from 1 to 10 years (partial correlations increasing from 0.14 (p=0.15) at age 1 to 0.27 (p=0.004) at age 10). Adjusting for height reduced the mean genotype difference in IQ to 5.5 (95 percent CI 0.6 to 10.3) points at age 1 and 10 2.6 points (95 percent CI 0.6 to 10.3) points at age 10. Prepubertal height therefore accounted for much of the genotype difference in IQ. It is speculated that early factors, possibly nutritional, contribute to both impaired growth and mental development in sickle cell disease(AU)

Intelligence in adolescents with homozygous sickle cell (SS) disease

Strokes occur in approximately 8 percent of children with SS disease most commonly below age 15 years. The cause is generally cerebral infraction secondary to occlusion of major cerebral vessels. Less extensive cerebral lesions might also occur producing subtle defects of cerebral function. This hypothesis has been tested using the Wechsler Intelligence Scales-Revised (WISC-R) adjusted to Jamaican conditions in SS children and controls followed from birth in the Jamaican cohort study. The first 125 children with SS disease were each matched with 2 children of the same sex and age but with a normal haemoglobin (AA) genotype. IQ scores in 60 age/sex matched pairs (1SS; 1AA) of cohort children aged 15-18 years were normally distributed in both genotypes but average IQ was significantly lower in SS disease (p<0.01). The possible mechanism of this defect are being explored. (AU)

Intellectual impairment in adolescents with sickle-cell disease - abstract

Sickle-cell disease is known to lead to increased incidence of the major neurological complication, stroke. The findings of several studies suggest that it can also give rise to less obvious neurological sequelae that manifest in more subtle clinical signs and deficits in neuropsychological functioning, particularly intellectual functioning. It is known, however, that chronic illnesses such as sickle-cell disease are associated with psychosocial factors such as school absenteeism and decreased activity that could also contribute to intellectual impairment. This study examined intellectual status and activity scale scores in 60 adolescents with homozygous (SS) sickle-cell disease and no history of stroke, compared to 60 normal (AA) controls matched for age, sex and socioeconomic background. All subjects were taken from a cohort group followed from birth at the sickle-cell clinic, MRC Laboratories Kingston, Jamaica. School attendance was examined in those subjects still attending school. Sickle-cell disease was found to be related to significant lowering of intelligence test scores (IQ) by 5.6 points on average, suggesting intellectual impairment. There was no relationship between school absenteeism, activity level and genotype or IQ, suggesting psychosoical factors did not contribute to lowered IQ in this group. Patterns of IQ scores in subjects with the disease suggested the likelihood of organicity, of a diffuse or generalized nature. Results suggest that IQ levels in sickle-cell disease are generally lower than in normal children and that this is likely to be the result of subtle neurological complications, even in the absence of stroke. Pathogenesis and onset are not at present known but merit further investigation (AU)

Evidence that dendritic cells are infected with HTLV-1 and are involved in the pathogenesis of tropical spastic paraparesis - abstract

The human T-cell leukaemia retrovirus 1 (HTLV-1) causes an aggressive leukaemia and also a non-malignant neurological syndrome - tropical spastic paraparesis [TSP]. The two conditions rarely coincide and it is unclear how the virus apparently leads to such distinct pathologies. We investigated whether deranged antigen presentation by potent dendritic cells (DC) could initiate the "spontaneous proliferation", which characterizes peripheral blood T-cells from HLTV-1 infected patients, in vitro. Mononuclear cells were separated from 7 HTLV-1/TSP patients and 3 HTLV-1 carriers and cultured in 20 æl hanging drops in inverted Terasaki plates. Spontaneous proliferation (measured by 3H thymidine uptake) was respectively 2- and 10-fold that of seronegative controls. Stringent depletion of B cells, macrophages and DCs produced highly purified T-cells whose proliferation was reduced to uninfected normal levels. Adding back the DCs restored excess proliferation (>6-fold), partially blocked by anti-DR antibody. Other cells had no effect. In situ hybridization revealed infection of DCs by HTLV-1. These results suggest that DCs are closely related to pathological T-cell behaviour in TSP patients with less aberrant effects in HTLV-1 carriers. We suggest that DCs are central to the pathogenic T-cell response which probably leads to the paraparesis (AU)

Extraversion and stimulation-seeking as factors in overeating and obesity

A clinical impression concerning overeating and obesity led to a review of the relevant research and culmination in a research hypothesis. This stated that eating was in many people not only a means of satiating hunger, but a means of obtaining stimulation and part of a general tendency to 'overindulge'. In the research, overeating was found to be linked to high external responsiveness, and sensation seeking to low basal arousal level. Eating as a form of sensation seeking was the subject of this study. The role of arousal level and externality were also examined. Three measures were chosen: a measure of extraversion, of sensation seeking and of basal arousal level (resting pulse rate). These were administered to a small randomly selected sample of subjects, who were then divided into a normal weight and an overweight group, using a 5 percent overweight cutoff point. In addition, a questionnaire was administered, and a standard structured interview given to a subgroup. Results showed the overweight group to be significantly higher on extraversion. The overweight group were found to be differentiated into two groups, the mildly overweight and the very overweight. The mildly overweight were the most extraverted and the highest sensation seeking of all three groups. The overweight group had a lower mean pulse rate than the normal group. The overweight group were higher on the Boredom Susceptibility and Experience Seeking factors of the sensation seeking measure. The mildly overweight smoked and drank more than any other group, suggesting a general pattern of overindulgence. The overweight group as a whole preferred non-physical and non-risk activities. They disliked monotonous activities. It appeared that whereas eating provided stimulation, it appeared to be stimulation of a low intensity type that is easily obtained. Implications were that overeating is a 'normal' response to prevalent food cues in the society, given man's genetic adaptations over the centuries. Treatment should be both curative and preventative, and should take the whole individual into account as obesity is the result of physiological, psychological and environmental factors (AU)