Objective: Cerebrovascular reactivity is impaired in patients suffering from obstructive sleep apnea syndrome (OSAS) as demonstrated by transcranial Doppler studies. We use magnetic resonance imaging techniques to investigate the anatomical distribution of cerebrovascular reactivity changes in patients with OSAS, as well as their evolution after therapeutic and sham continuous positive airway pressure (CPAP) treatment.
Methods: Twenty-three men with moderate or severe obstructive sleep apnea were compared to a healthy control group (n=7) using a breath-holding functional magnetic resonance imaging task and the flow-sensitive alternating inversion recovery (FAIR) imaging before and after 2 months of therapeutic (active) or sub-therapeutic (sham) CPAP treatment.
Introduction: Obstructive sleep apnea syndrome (OSAS) is a frequent breathing disorder occurring during sleep that is characterized by recurrent hypoxic episodes and sleep fragmentation. It remains unclear whether OSAS leads to structural brain changes, and if so, in which brain regions. Brain region-specific gray and white matter volume (GMV and WMV) changes can be measured with voxel-based morphometry (VBM).
View Article and Find Full Text PDFIntroduction: Functional magnetic resonance imaging studies enable the investigation of neural correlates underlying behavioral performance. We investigate the effect of active and sham Continuous Positive Airway Pressure (CPAP) treatment on working memory function of patients with Obstructive Sleep Apnea Syndrome (OSAS) considering Task Positive and Default Mode networks (TPN and DMN).
Methods: An experiment with 4 levels of visuospatial n-back task was used to investigate the pattern of cortical activation in 17 men with moderate or severe OSAS before and after 2 months of therapeutic (active) or sub-therapeutic (sham) CPAP treatment.
We investigated the contribution of postictal memory testing for lateralizing the epileptic focus and predicting memory outcome after surgery for temporal lobe epilepsy (TLE). Forty-five patients with TLE underwent interictal, postictal, and postoperative assessment of verbal and nonverbal memory. Surgery consisted of anterior temporal lobectomy (36), selective isolated amygdalohippocampectomy (6), or amygdalohippocampectomy coupled to lesionectomy (3).
View Article and Find Full Text PDFIntroduction: Functional magnetic resonance imaging (fMRI) studies enable the investigation of neural correlates underlying behavioral performance. We investigate the working memory (WM) function of patients with untreated obstructive sleep apnea (OSA) from the view point of task positive and default mode networks (TPN and DMN, respectively) and compare the results to those of healthy controls (HC).
Methods: A parametric fMRI experiment with 4 levels of visuospatial N-back task was used to investigate the pattern of cortical activation in 17 men with untreated moderate or severe OSA and 7 age-matched HC.
Purpose: Unilateral spatial neglect, defined as a failure to report, respond, or orient to stimuli that are presented contralaterally, has been widely documented after brain damage to right, and to a lesser degree, left frontotemporoparietal networks. Group studies involving patients with seizures with a lateralized focus have demonstrated transient dysfunctions in memory and language; however, so far, only two case reports have described transient neglect after an epileptic seizure.
Methods: To assess the existence and consistency of this phenomenon, we evaluated 33 epilepsy patients on a line-bisection task in interictal and postictal states as compared with an age- and sex-matched control group.
Purpose: Clinically silent lesions localized in the splenium of the corpus callosum (SCC) are a rare finding in the magnetic resonance imaging (MRI) of patients receiving antiepileptic drugs (AEDs). They are usually of benign character but may induce unnecessary complementary examinations if their nature is unrecognized. So far, 22 cases have been described in the literature, for which different etiologies have been proposed.
View Article and Find Full Text PDFAround 10,000 patients with pharmacoresistant epilepsy are living in Switzerland for whom surgical treatment potentially represents an alternative to medical treatment. Here we discuss the results of the first 250 patients investigated in the presurgical epilepsy unit Geneva-Lausanne since its foundation in April 1995. Two thirds of these patients were adults and one third children and adolescents.
View Article and Find Full Text PDF