Sleep polygraphy in Angelman syndrome.

OBJECTIVE: Sleep disturbances are frequent in Angelman syndrome (AS); however, beside the few studies which have investigated sleep disorders in AS by means of questionnaires, to our knowledge, no systematic polysomnographic recordings have been carried out in AS patients. The present study represents the first attempt to study sleep patterns of AS by polysomnography, to evaluate the influences of sleep on the paroxysmal electroencephalogram (EEG) patterns of AS and to assess the eventual age-related changes of sleep architecture and of sleep EEG abnormalities in children and adolescents with AS. METHODS: Fifteen children with AS (7 males and 8 females, mean age 7.2 years, range 3-16 years), attending the Sleep Center of the Department of Child Neurology and Psychiatry of the University of Rome 'La Sapienza' and the Sleep Research Centre of the Oasi Institute (IRCCS) of Troina were included and subdivided into two subgroups by age: subgroup 1, aged 3-5 years, and subgroup 2, aged 9-17 years. Two control groups of age-matched normal subjects were also included: one aged less than 8 years and another aged more than 8 years; additionally, two other groups of age-matched children with epilepsy and mental retardation of different origin, one aged less and one aged more than 9 years were taken into consideration. The statistical comparison between the sleep parameters obtained from the patients and those from the other groups was carried out by means of the non-parametric Kruskal-Wallis ANOVA and the Mann-Whitney U test. RESULTS: The most frequent EEG abnormality found in AS patients appeared to be the 2-3 c/s poorly defined spike/waves complexes. This pattern was influenced by sleep stages; the duration of the runs showed an increasing length with sleep deepening from sleep stage 1 to slow-wave sleep (SWS). Moreover, the 2-3 c/s bursts activity present in sleep stage 2 showed a slowing to 1-2 c/s during SWS. Regarding sleep architecture, in subjects with AS aged <8 year there was a significant reduction in sleep efficiency as compared to normal controls, while the percentage and duration of REM sleep was significantly lower and the percentage of SWS was significantly higher. REM sleep time was reduced in AS subjects aged >8 years than in normal controls. The comparison between AS groups and mental retardation with epilepsy groups did not show significant differences. CONCLUSIONS: Similarly to other types of genetically determined mental retardation syndromes, also subjects with AS seems to show important abnormalities of their sleep polysomnographic patterns. SIGNIFICANCE: This is the first study which reports, in detail, these abnormalities and opens a new path for further insight into the knowledge of additional sleep-related disturbances which are reported in sleep questionnaires by the caregivers of AS subjects.     

Diffusion-weighted imaging study of patients with essential tremor.

The pathophysiology of essential tremor (ET) is unknown. PET and fMRI studies have revealed bilateral activation and (1)H-MRS studies metabolic abnormalities in the cerebellum and other functionally related brain structures in ET. Diffusion-weighted imaging (DWI) was used to search for evidence of tissue integrity abnormalities in these areas in ET patients and 10 matched controls by calculating water apparent diffusion coefficients (ADCs). Regions of interest included the left and right cerebellum, red nucleus, thalamus, caudate, putamen, pallidum, and frontal white matter. Histograms of ADCs were generated for all pixels in the infratentorial compartment and manually segmented areas corresponding to brainstem, vermis, and cerebellar hemispheres. ADC values were similar in all brain areas in patients and controls. Our study did not detect changes affecting the investigated brain regions in ET patients. These findings argue against major structural damage in the ET brain, although more subtle neurodegenerative changes cannot be ruled out.     

Blink reflex abnormalities in children with Tourette syndrome

Tourette syndrome (TS) is a common disorder which typically occurs during childhood or early adolescence. There is no definitive diagnostic test for TS. The objective of this study was to demonstrate whether neurophysiological abnormalities of the blink reflex can be observed in children with TS. We enrolled 15 children with TS, diagnosed according to DSM IV Diagnostic Criteria, and 15 controls. The blink reflex was elicited by stimulating the supraorbital nerve in order to measure the early response (R1), homolateral and contralateral R2 (late) responses, amplitude of R1 and duration of R2. The mean duration of R2 was significantly longer in TS patients than in the controls ( P  < 0.001, Student's t -test). An abnormal pattern of the blink reflex can be, even in childhood, an early neurophysiologic marker of TS, which is not related to the duration of TS or to the age of onset.     

Sources of cortical rhythms change as a function of cognitive impairment in pathological aging: a multicenter study.

OBJECTIVE: The present study tested the hypothesis that cortical electroencephalographic (EEG) rhythms. change across normal elderly (Nold), mild cognitive impairment (MCI), and Alzheimer's disease (AD) subjects as a function of the global cognitive level. METHODS: Resting eyes-closed EEG data were recorded in 155 MCI, 193 mild AD, and 126 age-matched Nold subjects. EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), and beta 2 (20-30 Hz). EEG cortical sources were estimated by LORETA. RESULTS: Occipital delta and alpha 1 sources in parietal, occipital, temporal, and 'limbic' areas had an intermediate magnitude in MCI subjects compared to mild AD and Nold subjects. These five EEG sources presented both linear and nonlinear (linear, exponential, logarithmic, and power) correlations with the global cognitive level (as revealed by mini mental state examination score) across all subjects. CONCLUSIONS: Cortical EEG rhythms change in pathological aging as a function of the global cognitive level. SIGNIFICANCE: The present functional data on large populations support the 'transitional hypothesis' of a shadow zone across normality, pre-clinical stage of dementia (MCI), and AD.     

A comparison of propofol, midazolam, and methohexital for sedation during retrobulbar and peribulbar block.

STUDY OBJECTIVE: To compare the efficacy of propofol, methohexital, and midazalom in providing adequate sedation during administration of retrobulbar block and satisfactory postoperative amnesia. DESIGN: Retrospective chart review over a 4-month period. SETTING: Ambulatory patients in the main operating room of a university-affiliated hospital. PATIENTS: One hundred forty-seven ambulatory patients undergoing ophthalmologic surgery of less than 2 hours' duration under regional anesthesia consisting of retrobulbar or peribulbar block and intravenous (IV) sedation. INTERVENTIONS: One of three drugs--propofol 0.47 +/- 0.06 mg/kg, midazolam 0.02 +/- 0.005 mg/kg, or methohexital 0.45 +/- 0.16 mg/kg--was administered IV. Patients were observed for a minimum of 60 seconds or until adequate sedation was achieved, after which a retrobulbar or peribulbar block was performed. MEASUREMENTS AND MAIN RESULTS: Blood pressure, electrocardiogram, and oxygen saturation were monitored and recorded. Patients were observed for apnea, hiccups, pain on injection, excitement, tremor, grimacing, or verbal response during the block. The requirement for additional sedation intraoperatively was noted. Patients were questioned postoperatively in the ambulatory recovery room for recall of needle insertion or discomfort during the block, as well as about their satisfaction with the overall experience. CONCLUSIONS: Grimacing or verbal response during the retrobulbar or peribulbar block did not predict or correlate with patient recall. Propofol was equal to both midazolam and methohexital in providing adequate sedation and postoperative amnesia but possesses the added advantages of reduced postoperative vomiting, lower intraocular pressure, and earlier return-to-home readiness.     

Childhood fractures are associated with decreased bone mass gain during puberty: an early marker of persistent bone fragility?

Whether peak bone mass is low among children with fractures remains uncertain. In a cohort of 125 girls followed over 8.5 years, 42 subjects reported 58 fractures. Among those, BMC gain at multiple sites and vertebral bone size at pubertal maturity were significantly decreased. Hence, childhood fractures may be markers of low peak bone mass acquisition and persistent skeletal fragility. INTRODUCTION: Fractures in childhood may result from a deficit in bone mass accrual during rapid longitudinal growth. Whether low bone mass persists beyond this period however remains unknown. MATERIALS AND METHODS: BMC at the spine, radius, hip, and femur diaphysis was prospectively measured over 8.5 years in 125 girls using DXA. Differences in bone mass and size between girls with and without fractures were analyzed using nonparametric tests. The contribution of genetic factors was evaluated by mother-daughter correlations and that of calcium intake by Cox proportional hazard models. RESULTS: Fifty-eight fractures occurred in 42 among 125 girls (cumulative incidence, 46.4%), one-half of all fractures affecting the forearm and wrist. Girls with and without fractures had similar age, height, weight. and calcium intake at all time-points. Before and during early puberty, BMC and width of the radius diaphysis was lower in the fracture compared with no-fracture group (p < 0.05), whereas aBMD and BMAD were similar in the two groups. At pubertal maturity (Tanner's stage 5, mean age +/- SD, 16.4 +/- 0.5 years), BMC at the ultradistal radius (UD Rad.), femur trochanter, and lumbar spine (LS), and LS projected bone area were all significantly lower in girls with fractures. Throughout puberty, BMC gain at these sites was also decreased in the fracture group (LS, -8.0%, p = 0.015; UD Rad., -12.0%, p = 0.004; trochanter, -8.4%, p = 0.05 versus no fractures). BMC was highly correlated between prepuberty and pubertal maturity (R = 0.54-0.81) and between mature daughters and their mothers (R = 0.32-0.46). Calcium intake was not related to fracture risk. CONCLUSIONS: Girls with fractures have decreased bone mass gain in the axial and appendicular skeleton and reduced vertebral bone size when reaching pubertal maturity. Taken together with the evidence of tracking and heritability for BMC, these observations indicate that childhood fractures may be markers for low peak bone mass and persistent bone fragility.     

Role of Tyrosine Kinase in Desflurane-induced Preconditioning

Background: Short administration of volatile anesthetics preconditions myocardium and protects the heart against the consequences of subsequent ischemia. Activation of tyrosine kinase is implicated in ischemic preconditioning. The authors investigated whether desflurane-induced preconditioning depends on activation of tyrosine kinase.

Methods: Sixty-four rabbits were instrumented for measurement of left ventricular pressure, cardiac output, and myocardial infarct size (IS). All rabbits were subjected to 30 min of occlusion of a major coronary artery and 2 h of subsequent reperfusion. Rabbits underwent a treatment period consisting of either no intervention for 35 min (control group, n = 12) or 15 min of 1 minimum alveolar concentration desflurane inhalation followed by a 10-min washout period (desflurane group, n = 12). Four additional groups received the tyrosine kinase inhibitor genistein (5 mg/kg) or lavendustin A (1.3 mg/kg) at the beginning of the treatment period with (desflurane-genistein group, n = 11; desflurane-lavendustin A group, n = 12) or without desflurane inhalation (genistein group, n = 9; lavendustin A group, n = 8).

Results: Hemodynamic values were similar in all groups during baseline (left ventricular pressure, 87 +/- 14 mmHg [mean +/- SD]; cardiac output, 198 +/- 47 ml/min), during coronary artery occlusion (left ventricular pressure, 78 +/- 12 mmHg; cardiac output, 173 +/- 39 ml/min), and after 2 h of reperfusion (left ventricular pressure, 59 +/- 17; cardiac output, 154 +/- 43 ml/min). IS in the control group was 55 +/- 10% of the area at risk. The tyrosine inhibitors had no effect on IS (genistein group, 56 +/- 13%; lavendustin A group, 49 +/- 13%; each P = 1.0 vs. control group). Desflurane preconditioning reduced IS to 40 +/- 15% (P = 0.04 vs. control group). Tyrosine kinase inhibitor administration had no effect on IS reduction (desflurane-genistein group, 44 +/- 13%; desflurane-lavendustin A group, 44 +/- 16%; each P = 1.0 vs. desflurane group).     

gamma-ray spectrometry of soil samples from the Provincia dell'Aquila (Central Italy).

In the Abruzzo Region (Central Italy) there is a lack of measurements of gamma-ray activity in soils and waters. For this reason, we have planned to carry out a systematic measurement of soils in the area of the Provincia dell'Aquila, which covers about one-half of the entire region. In this paper we report the results obtained from 56 soil samples, collected in the northern part of the area of interest (about one-fourth of the total area under study). The results, in terms of content of uranium, thorium and potassium and the activity of caesium are reported, as well as the details on the experimental procedure. The results show a limited content of K and U, with no large variations from site to site, in agreement with the expectations based on the knowledge of the geo-lithological nature of the soil. The amount of Th is also quite limited, with a few exceptions where the Th content is up to five times the average value. Caesium, originated from the fall-out following the Chernobyl accident, is very irregularly distributed owing to the complicated orography of the land. Future plans are also shortly discussed.