The aim of this study was to investigate potential differences in neural structure in individuals with Asperger syndrome (AS), high-functioning individuals with autism spectrum disorder (ASD). The ...main symptoms of AS are severe impairments in social interactions and restricted or repetitive patterns of behaviors, interests or activities.
Diffusion weighted magnetic resonance imaging data were acquired for 14 adult males with AS and 19 age, sex and IQ-matched controls. Voxelwise group differences in fractional anisotropy (FA) were studied with tract-based spatial statistics (TBSS). Based on the results of TBSS, a tract-level comparison was performed with constrained spherical deconvolution (CSD)-based tractography, which is able to detect complex (for example, crossing) fiber configurations. In addition, to investigate the relationship between the microstructural changes and the severity of symptoms, we looked for correlations between FA and the Autism Spectrum Quotient (AQ), Empathy Quotient and Systemizing Quotient.
TBSS revealed widely distributed local increases in FA bilaterally in individuals with AS, most prominent in the temporal part of the superior longitudinal fasciculus, corticospinal tract, splenium of corpus callosum, anterior thalamic radiation, inferior fronto-occipital fasciculus (IFO), posterior thalamic radiation, uncinate fasciculus and inferior longitudinal fasciculus (ILF). CSD-based tractography also showed increases in the FA in multiple tracts. However, only the difference in the left ILF was significant after a Bonferroni correction. These results were not explained by the complexity of microstructural organization, measured using the planar diffusion coefficient. In addition, we found a correlation between AQ and FA in the right IFO in the whole group.
Our results suggest that there are local and tract-level abnormalities in white matter (WM) microstructure in our homogenous and carefully characterized group of adults with AS, most prominent in the left ILF.
We evaluated the clinical role of positron emission tomography (PET) in 23 children with tuberous sclerosis complex. Mean age of the children when first scanned was 3.3 years. Mean age when seizures ...began was 8.7 months. All, except three, were at least mildly developmentally delayed. PET images were visually analyzed and compared to computed tomography (CT), magnetic resonance imaging (MRI), and the electroencephalogram (EEG). In two infants, interictal PET study was normal. One of the studies was performed with a low resolution early generation scanner at age 7 months; the other infant was 2 days old. Twenty-one of the 23 children had focal or multifocal cortical hypometabolism. Some hypometabolic cortical regions on PET did not show corresponding abnormalities on CT and MRI, and may be due to epileptogenic mechanisms or small tubers. PET provides additional localizing information to CT and MRI in patients with tuberous sclerosis complex. However, because of the normally low cerebral glucose metabolism in infancy, PET may give false negative findings if performed prior to about 1 year of age. The usefulness of glucose metabolism PET in most patients with tuberous sclerosis complex is limited. However, if the EEG, CT, and MRI abnormalities are unifocal or unilateral, and surgery is being contemplated, more detailed evaluation with PET may help to determine if contralateral tubers are present and evaluate the functional integrity of the brain as a whole.
Recent brain imaging findings suggest that there are widely distributed abnormalities affecting the brain connectivity in individuals with autism spectrum disorder (ASD). Using graph theoretical ...analysis, it is possible to investigate both global and local properties of brain's wiring diagram, i.e., the connectome.
We acquired diffusion-weighted magnetic resonance imaging data from 14 adult males with high-functioning ASD and 19 age-, gender-, and IQ-matched controls. As with diffusion tensor imaging-based tractography, it is not possible to detect complex (e.g., crossing) fiber configurations, present in 60-90 % of white matter voxels; we performed constrained spherical deconvolution-based whole brain tractography. Unweighted and weighted structural brain networks were then reconstructed from these tractography data and analyzed with graph theoretical measures.
In subjects with ASD, global efficiency was significantly decreased both in the unweighted and the weighted networks, normalized characteristic path length was significantly increased in the unweighted networks, and strength was significantly decreased in the weighted networks. In the local analyses, betweenness centrality of the right caudate was significantly increased in the weighted networks, and the strength of the right superior temporal pole was significantly decreased in the unweighted networks in subjects with ASD.
Our findings provide new insights into understanding ASD by showing that the integration of structural brain networks is decreased and that there are abnormalities in the connectivity of the right caudate and right superior temporal pole in subjects with ASD.
The Landau-Kleffner syndrome is sometimes associated with continuous spike-waves during slow-wave sleep. The clinical significance of this association is unclear. In order to investigate differences ...in glucose metabolic patterns between awake and sleep states in two children with Landau-Kleffner syndrome and continuous spike-waves during slow-wave sleep, fluorodeoxyglucose positron-emission tomographic (PET) studies were performed in each state. In the first patient, the awake interictal PET study revealed moderate hypometabolism in the thalamus and frontal and temporal cortex and mild hypometabolism in the parietal and anterior cingulate cortex bilaterally. Occipital cortex was severely hypometabolic bilaterally. In a repeat PET study performed during sleep in which continuous spike-waves during slow-wave sleep were present, the only difference noted compared to the awake study was a marked bilateral increase in temporal cortex metabolism. The awake interictal PET in the second child was normal, except for mildly increased relative glucose metabolism in the left inferior temporal cortex. The sleep PET study with continuous spike-waves during slow-wave sleep in this child showed hypermetabolism in both temporal lobes; however, this was more pronounced, with a wider distribution in the left temporal cortex. In normal subjects, PET studies performed during awake and sleep states have not revealed such differences. Whether the temporal lobes are involved in the generation of continuous spike-waves during slow-wave sleep remains to be confirmed in a larger group of patients. The first child was treated surgically with multiple subpial transection, following which continuous spike-waves during slow-wave sleep disappeared and language function improved.
To determine seizure propagation patterns, we analyzed ictal positron emission tomography (PET) studies of regional cerebral glucose utilization in 18 children (11 male and 7 female aged 2 weeks to ...16 years) with epilepsy (excluding infantile spasms IS). Three major metabolic patterns were determined based on degree and type of subcortical involvement: Nine children had type I; asymmetric glucose metabolism of striatum and thalamus. Of these, the 7 oldest children showed unilateral cortical hypermetabolism (always including frontal cortex) and crossed cerebellar hypermetabolism. Two infants (aged < 1 year) had a similar ictal PET pattern but no cerebellar asymmetry, presumably owing to immaturity of corticopontocerebellar projections. Five children had type II, symmetric metabolic abnormalities of striatum and thalamus; this pattern was accompanied by hippocampal or insular cortex hypermetabolism, diffuse neocortical hypometabolism, and absence of any cerebellar abnormality. Four children had type III, hypermetabolism restricted to cerebral cortex. This classification can accommodate ictal PET and single photon emission computed tomography (SPECT) patterns described by other investigators. Future studies should be directed at the clinical relevance of this classification, particularly with regard to epilepsy surgery.
Purpose: Increased risk of death has been reported in patients with intractable epilepsy (IE) taking nitrazepam (NZP).
Methods: Between January 1983 and March 1994, 302 patients with IE were entered ...into a NZP compassionate‐plea protocol. NZP was discontinued if there was <50% seizure reduction or significant side effects. In some patients with >50% reduction, it also was discontinued for lack of sufficient effect. At the end of follow‐up for this study, 62 patients remained taking NZP. Patients took NZP from 3 days to 10 years.
Results: Twenty‐one of 302 patients died after institution of NZP. Fourteen of 21 of these were taking NZP at death, and in five of 21, the NZP had been discontinued. Two patients were excluded from analysis, because it is unclear whether NZP had been discontinued before death. Six other patients were lost from follow‐up. Of the 14 deaths with NZP, seven were sudden, six were of pneumonia, and one was of cystinosis. Nine had at least one contributing factor, such as dysphagia, gastro‐esophageal reflux, or recurrent aspirations. The 294 patients took NZP for a total of 704 patient years (ptyrs), and were discontinued for a total of 856 ptyrs. There were 1.98 deaths/100 ptyrs on NZP compared with 0.58 deaths/100 ptyrs without NZP, most of the former being associated with side effects of NZP. Mortality in patients younger than 3.4 years was 3.98 with NZP compared with 0.26 deaths/100 ptyrs without NZP (p = 0.0002). Corresponding figures in patients 3.4 years or older were 0.50 and 0.86 deaths/100 ptyrs, respectively.
Conclusions: NZP therapy for epilepsy apparently increases the risk of death, especially in young patients with IE. This should be considered in antiepileptic drug (AED) management decisions.
We performed positron emission tomographic (PET) studies with 2-deoxy-218Ffluoro-D-glucose in 8 children with hemimegalencephaly (HME). HME is a developmental brain malformation associated with ...epilepsy, hemianopsia, and varying degrees of developmental delay. We hypothesized that the relatively poor overall developmental outcome of surgically hemispherectomized HME patients as a group, compared to children undergoing hemispherectomy for Sturge-Weber syndrome or chronic focal encephalitis, is related to dysfunction of the structurally "normal" non-HME side and that PET would be helpful in the pre-surgical evaluation of HME patients with intractable epilepsy. Visual analysis of the non-HME side on PET clearly revealed evidence of cortical hypometabolism in 4 patients compared to controls. Seven children underwent epilepsy surgery. One child had a glucose metabolic pattern suggesting a cortical lamination defect in the non-HME hemisphere, bilateral independent seizure onset, and was not considered to be a surgical candidate. We found a general correlation between the pattern of glucose utilization in the less affected hemisphere and prognosis. Although the follow-up periods are short, it is recommended that HME children with intractable epilepsy undergo hemispherectomy in the first year of life in order to allow maximal brain plasticity to occur; however, preoperative evaluation should also include an assessment of the integrity of the non-HME hemisphere.
Sleep habits and disorders in Finnish schoolchildren SAARENPÄÄ‐HEIKKILÄ, OUTI A.; RINTAHAKA, PERTTI J.; LAIPPALA, PEKKA J. ...
Journal of sleep research,
September 1995, Letnik:
4, Številka:
3
Journal Article
Recenzirano
Odprti dostop
SUMMARY A variety of epidemiological sleep parameters was evaluated in 574 Finnish schoolchildren (age 7 to 17 years) and in their parents (454 mothers and 390 fathers). Three questionnaire forms ...were set, one for the pupil and two for his/her parents including information of sleep habits, disorders, and social background of the pupil and his/her family. The pupils were grouped by age (two preadolescent groups: 7.1–9.3 y and 9.4–13 y, adolescents 13.1–17.1 y) and sex. It was found that bedtime was more often after 22.00 hours among adolescents than preadolescents both at weekends and on weekdays. At weekends the wake‐up time was later in adolescents than preadolescents but on weekdays it was opposite in boys. On weekdays girls went earlier to bed than boys and woke up earlier than boys. Total sleep durations both on weekdays and at weekends were longer in preadolescent than in adolescent groups, and longer during weekend nights than on weekday nights in all groups. Girls experienced more dreaming and night waking, but boys snored more. Daytime sleepiness patterns were more common in adolescents than in preadolescents. Children who experienced daytime sleepiness more often had fathers with daily sleep urges.
An association was found between age and sleep habits and some daytime sleepiness patterns; adolescents went to bed later and slept less, and had more problems with alertness during daytime than preadolescents. Some differences were also found between boys and girls. The daytime sleepiness of pupils correlated with the same symptom in fathers.
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