Comparative validity between the Canadian and the Dutch norms of the Alberta Infant Motor Scale in a preterm population.

BACKGROUND: Prematurity remains a leading cause of motor developmental delays. The Alberta Infant Motor Scales (AIMS) is a useful tool to easily assess motor development. However, during the last decade, cross-cultural differences have been identified regarding the original AIMS norms. Therefore, the aim of this study is twofold: confirm the validity of the AIMS in a preterm population and compare the new Dutch AIMS norms to the original Canadian ones in our Belgian population. METHOD: Ninety-six preterm infants were assessed simultaneously on the AIMS and on the Bayley Scales of Infant-Toddler Development (Bayley-III) at age 9-14 months. Concurrent validity was evaluated by correlation analysis. Among these, 89 were assessed on the AIMS at age 3-6 months. Clinimetric properties of both AIMS norms were calculated to compare their ability to detect a motor delay on the Bayley-III at age 9-14 months. RESULT: Pearson's coefficient showed an excellent level of correlation between the two scales (r = 0.91). At age 3-6 months, only the 10th Canadian centile showed acceptable properties to predict a significant motor delay. At age 9-14 months, the 5th centile of both norms showed good properties to diagnose a significant motor delay, while only the Canadian norms seems to be sensitive enough to diagnose a mild motor delay. CONCLUSION: The new Dutch norms seem to be less sensitive but more specific than the Canadian ones and therefore require adapted cut-offs to diagnose motor developmental delays in a preterm population.

Reduced low-frequency heart rate variability relates to greater intimal-medial thickness of the carotid wall in two samples.

INTRODUCTION: We investigated the relationship between heart rate variability and preclinical carotid intima-media thickening, a putative index of atherosclerosis. METHODS: A sample of 350 men and women (mean age 56.8 years) selected for the presence or absence of untreated hypertension was assessed for heart rate variability at rest and separately for carotid intima-media thickness using duplex ultrasonography (Pittsburgh study). Findings from this sample were cross-validated in a subsample of 68 men drawn from the Kuopio Ischemic Heart Disease Risk Factor trial and selected for the presence or absence of angina. RESULTS: In both samples, regression analyses, controlling for known risk factors, showed a significant negative relationship between mean carotid intima-media thickness and low-frequency (0.05-0.15 Hz) heart rate variability, but not high-frequency variability. DISCUSSION: The mechanism underlying this relationship remains unclear. The absence of difference in high-frequency variation questions any interpretation in terms of vagal function; the difference in low-frequency variation may implicate vessel wall characteristics or decreased sympathetic nervous system influence. CONCLUSION: Decreased amplitude of low-frequency heart rate variability seems associated with a preclinical atherosclerotic index.

Prevalence and Specificity of the Abnormal Niacin Response: A Potential Endophenotype Marker in Schizophrenia.

The skin flush response to niacin is abnormally blunted among a subset of patients with schizophrenia (SZ), preferentially associates with SZ compared to other mental illnesses, occurs frequently in nonpsychotic members of SZ-affected families, appears heritable, and shows evidence of genetic association. The niacin response abnormality (NRA) may prove to be a useful SZ endophenotype. Using a laser Doppler flowmeter, we undertook this study to estimate the prevalence of NRA in SZ (n = 70), bipolar disorder (BP, n = 59), and healthy control (HC, n = 87) groups, and to estimate its specificity for the illness. From the dose-response curves, we calculated the concentration of methylnicotinate required to elicit a half-maximal blood flow (MBF) response (EC50 value) and MBF value for each subject. The median log10EC50 of the SZ was above the third quartile of log10EC50 of either the HC or BP groups, whereas the MBF was significantly lower in the SZ than in the HC or BP groups. With a definition of NRA of having both EC50 above the ninetieth percentile of the control samples and MBF response below the sixtieth percentile for the control range, the NRA predicted SZ with 31% sensitivity and 97% specificity. Moreover, the NRA was not influenced by age, gender, race, and cigarette smoking. In summary, the NRA may define a SZ subtype with a clinically significant phospholipid signaling defect. Understanding its molecular origins may shed light on the pathophysiology of SZ and suggest new tools for its early diagnosis and treatment.