Intensive versus subcutaneous insulin in patients with hyperacute stroke: results from the randomized INSULINFARCT trial.

BACKGROUND AND PURPOSE: Intensive insulin therapy (IIT) has not yet proven its efficacy on stroke prognosis or in the reduction of MRI infarct growth. The INSULINFARCT study aims at determining in patients with hyperacute stroke whether IIT, with a better control of poststroke hyperglycemia, would reduce subsequent MRI infarct growth than usual care with subcutaneous insulin. METHODS: One hundred eighty patients with MRI-proven ischemic stroke and with National Institutes of Health Stroke Scale from 5 to 25 at admission (<6 hours) were randomized to receive IIT or usual subcutaneous insulin for 24 hours. Admission hyperglycemia was not required for recruitment. Control MRI and 3-month follow-up (with functional outcome and serious adverse events) were planned. The primary objective was to detect a difference in the proportion of patients with mean capillary glucose test <7 mmol/L during 24 hours. The secondary objective was to investigate whether IIT would reduce infarct growth. The analysis was planned in intention-to-treat. Patients with >3 missing capillary glucose test were excluded (n=4). RESULTS: The proportion of patients with mean capillary glucose test <7 mmol/L in the first 24 hours was higher in the IIT group (95.4% [83 of 87] versus 67.4% [60 of 89]; P<0.0001). The infarct growth was lower in the subcutaneous insulin group (median, 10.8 cm(3); 95% CI, 6.5-22.4 versus 27.9 cm(3); 14.6-40.7; 60% of increase; P=0.04). The 3-month functional outcome (45.6% [41 of 90] versus 45.6% [41 of 90]), death (15.6% [14 of 90] versus 10% [9 of 90]), and serious adverse events (38.9% [35 of 90] versus 35.6% [32 of 90]) were similar in the subcutaneous insulin and IIT group. CONCLUSIONS: The IIT regimen improved glucose control in the first 24 hours of stroke but was associated with larger infarct growths. IIT cannot be recommended in hyperacute ischemic stroke. Clinical Trial Registration- URL: http://clinicaltrials.gov. Unique Identifier: NCT00472381.

MRI findings in 77 children with non-syndromic autistic disorder.

BACKGROUND: The clinical relevance of MR scanning in children with autism is still an open question and must be considered in light of the evolution of this technology. MRI was judged to be of insufficient value to be included in the standard clinical evaluation of autism according to the guidelines of the American Academy of Neurology and Child Neurology Society in 2000. However, this statement was based on results obtained from small samples of patients and, more importantly, included mostly insufficient MRI sequences. Our main objective was to evaluate the prevalence of brain abnormalities in a large group of children with a non-syndromic autistic disorder (AD) using T1, T2 and FLAIR MRI sequences. METHODOLOGY: MRI inspection of 77 children and adolescents with non-syndromic AD (mean age 7.4+/-3.6) was performed. All met the DSM-IV and ADI -R criteria for autism. Based on recommended clinical and biological screenings, we excluded patients with infectious, metabolic or genetic diseases, seizures or any other neurological symptoms. Identical MRI inspections of 77 children (mean age 7.0+/-4.2) without AD, developmental or neurological disorders were also performed. All MRIs were acquired with a 1.5-T Signa GE (3-D T1-FSPGR, T2, FLAIR coronal and axial sequences). Two neuroradiologists independently inspected cortical and sub-cortical regions. MRIs were reported to be normal, abnormal or uninterpretable. PRINCIPAL FINDINGS: MRIs were judged as uninterpretable in 10% (8/77) of the cases. In 48% of the children (33/69 patients), abnormalities were reported. Three predominant abnormalities were observed, including white matter signal abnormalities (19/69), major dilated Virchow-Robin spaces (12/69) and temporal lobe abnormalities (20/69). In all, 52% of the MRIs were interpreted as normal (36/69 patients). CONCLUSIONS: An unexpectedly high rate of MRI abnormalities was found in the first large series of clinical MRI investigations in non-syndromic autism. These results could contribute to further etiopathogenetic research into autism.

Impairment of cerebello-thalamo-frontal pathway in Rab-GDI mutated patients with pure mental deficiency.

BACKGROUND: Rab-GDI mutations are responsible for "pure" mental deficiency, without any specific clinical features or brain malformation. Therefore, screening for mutations in mentally retarded patients is not available on a routine basis. Moreover, neuronal networks involved in mental deficiency still remain largely unknown. METHODS: We performed a fine neuropsychological and imaging study in five patients from two unrelated families, affected with mental deficiency due to a mutation in the Rab-GDI gene. High resolution 3D brain MRI of the five mentally retarded adult males (mean age 33 years) were compared to MRI of 14 healthy males (mean age 35 years) using a Voxel-Based Morphometric analysis (VBM). RESULTS: All patients had isolated moderate mental retardation (WAIS-III IQ range, 41-50; mean 45) without specific morphological or behavioural features. No obvious brain abnormality was observed on visual inspection of individual scans. Using VBM analysis, Rab-GDI mutated patients' MRIs exhibited significant brain changes compared to normal subjects (p<0.05, corrected for multiple comparisons): increased grey matter density in left cerebellum and in left angular gyrus, decreased grey matter volume in thalami, decreased white matter density in prefrontal lobes, right fusiform occipito-temporal gyrus, and decreased white matter volume in cerebellar peduncles. CONCLUSIONS: These morphological changes observed in Rab-GDI mutated patients, mainly localized in the cerebello-thalamo-prefrontal pathway, are consistent with the hypothesis that the cerebellum is one of the critical components of a global learning network. Our results open new avenues in the diagnosis of non-specific mental deficiency using gene-specific "brain maps" as endophenotypes.

Autism, the superior temporal sulcus and social perception.

The most common clinical sign of autism spectrum disorders (ASD) is social interaction impairment, which is associated with communication deficits and stereotyped behaviors. Based on recent brain-imaging results, our hypothesis is that abnormalities in the superior temporal sulcus (STS) are highly implicated in ASD. STS abnormalities are characterized by decreased gray matter concentration, rest hypoperfusion and abnormal activation during social tasks. STS anatomical and functional anomalies occurring during early brain development could constitute the first step in the cascade of neural dysfunction underlying ASD. We will focus this review on the STS, which has been highly implicated in social cognition. We will review recent data on the contribution of the STS to normal social cognition and review brain-imaging data implicating this area in ASD. This review is part of the INMED/TINS special issue "Nature and nurture in brain development and neurological disorders", based on presentations at the annual INMED/TINS symposium (http://inmednet.com/).

[Autism: neuroimaging]. / Autismo: neuroimagem.

Autism is a neurodevelopmental disorder with a range of clinical presentations. These presentations vary from mild to severe and are referred to as autism spectrum disorders. The most common clinical sign of autism spectrum disorders is social interaction impairment, which is associated with verbal and non-verbal communication deficits and stereotyped and repetitive behaviors. Thanks to recent brain imaging studies, scientists are getting a better idea of the neural circuits involved in autism spectrum disorders. Indeed, functional brain imaging, such as positron emission tomography, single foton emission tomography and functional MRI have opened a new perspective to study normal and pathological brain functioning. Three independent studies have found anatomical and rest functional temporal lobe abnormalities in autistic patients. These alterations are localized in the superior temporal sulcus bilaterally, an area which is critical for perception of key social stimuli. In addition, functional studies have shown hypoactivation of most areas implicated in social perception (face and voice perception) and social cognition (theory of mind). These data suggest an abnormal functioning of the social brain network in autism. The understanding of the functional alterations of this important mechanism may drive the elaboration of new and more adequate social re-educative strategies for autistic patients.

Autismo: neuroimagem / Autism: neuroimaging

O autismo é um transtorno de neurodesenvolvimento com diversas apresentações clínicas. Essas apresentações variam em gravidade (leves a graves) e são denominadas transtornos do espectro do autismo. O sinal mais comum aos transtornos desse espectro é o déficit de interação social, que está associado a déficits de comunicação verbal e não-verbal e a comportamentos estereotipados e repetitivos. Graças a estudos recentes que utilizam métodos de imagem cerebral, os cientistas obtiveram uma idéia melhor dos circuitos neurais envolvidos nos transtornos do espectro do autismo. De fato, os exames de imagem cerebral funcionais, como tomografia por emissão de pósitrons, tomografia por emissão de fóton único e ressonância magnética funcional abriram uma nova perspectiva para o estudo do funcionamento cerebral normal e patológico. Três estudos independentes encontraram anormalidades da anatomia e do funcionamento em repouso do lobo temporal em pacientes autistas. Essas alterações estão localizadas bilateralmente nos sulcos temporais superiores. Essa região anatômica é de grande importância para a percepção de estímulos sociais essenciais. Além disso, estudos funcionais demonstraram hipoativação da maior parte das áreas envolvidas na percepção social (percepção de faces e voz) e cognição social (teoria da mente). Esses dados sugerem um funcionamento anormal da rede de pensamentos do cérebro social no autismo. A compreensão das alterações nesse importante mecanismo pode estimular a elaboração de novas e mais adequadas estratégias sociais de reeducação para pacientes autistas.

Autism severity and temporal lobe functional abnormalities.

Two independent studies have described bilateral temporal hypoperfusion in autistic children. Temporal regions are implicated in social perception, language, and "theory-of-mind," abilities that are impaired in autism. We investigated a putative relationship between cerebral blood flow (rCBF) measured at rest and clinical profile of 45 autistic children (Autism Diagnostic Interview-Revised [ADI-R] scores). A whole-brain covariance analysis was performed. Significant negative correlation was observed between rCBF and ADI-R score in the left superior temporal gyrus. The more severe the autistic syndrome, the more rCBF is low in this region, suggesting that left superior temporal hypoperfusion is related to autistic behavior severity.