20 research outputs found
Atypical Balance between Occipital and Fronto-Parietal Activation for Visual Shape Extraction in Dyslexia
Reading requires the extraction of letter shapes from a complex background of text, and an impairment in visual shape extraction would cause difficulty in reading. To investigate the neural mechanisms of visual shape extraction in dyslexia, we used functional magnetic resonance imaging (fMRI) to examine brain activation while adults with or without dyslexia responded to the change of an arrow’s direction in a complex, relative to a simple, visual background. In comparison to adults with typical reading ability, adults with dyslexia exhibited opposite patterns of atypical activation: decreased activation in occipital visual areas associated with visual perception, and increased activation in frontal and parietal regions associated with visual attention. These findings indicate that dyslexia involves atypical brain organization for fundamental processes of visual shape extraction even when reading is not involved. Overengagement in higher-order association cortices, required to compensate for underengagment in lower-order visual cortices, may result in competition for top-down attentional resources helpful for fluent reading.Ellison Medical FoundationMartin Richmond Memorial FundNational Institutes of Health (U.S.). (Grant UL1RR025758)National Institutes of Health (U.S.). (Grant F32EY014750-01)MIT Class of 1976 (Funds for Dyslexia Research
Developmental delay and connective tissue disorder in four patients sharing a common microdeletion at 6q13-14
Interstitial deletions of the long arm of chromosome 6 are rare, and most reported cases represent large, cytogenetically detectable deletions. The implementation of array comparative genome hybridisation in the diagnostic work-up of patients presenting with congenital disorders, including developmental delay, has enabled identification of many patients with smaller chromosomal imbalances. In this report, the cases are presented of four patients with a de novo interstitial deletion of chromosome 6q13-14, resulting in a common microdeletion of 3.7 Mb. All presented with developmental delay, mild dysmorphism and signs of lax connective tissue. Interestingly, the common deleted region harbours 16 genes, of which COL12A1 is a good candidate for the connective tissue pathology
Spontaneous spinal epidural hematoma in infancy: Review of the literature and the “seventh” case report
Abstract: Spontaneous spinal epidural hematomas (SSEH) are a rare cause of spinal cord compression in childhood and especially in infancy. We reviewed the literature and describe a case of an 8-month-old boy with a large spontaneous cervico-thoracic epidural hematoma. With this review we want to detail the importance of early investigation, diagnosis and treatment in infants with SSEH. In our case the infant presented with irritability and crying and an ascending paralysis within four days. Magnetic resonance imaging (MRI) of the spine demonstrated an extensive epidural hematoma between C5 and L1, serious medullar compression and secondary cervical and thoracic medullar edema and hydromyelia. An emergency laminectomy was performed with evacuation of a well organized hematoma. There was a partial recuperation of the neurologic symptoms. Based on the scarce literature which only concerns seven case reports, SSEH is a rare cause of spinal compression in infancy. The presentation is often not specific and neurological symptoms are often lacking in the beginning. However early diagnosis with MRI and prompt neurosurgical intervention are important to improve outcome