Obstructive sleep apnea is a common disorder with important sequelae. 1-7 Aging substantially increases the risk of obstructive apnea, 8-11 although the mechanisms underlying this predisposition remain unclear. 8,12-15 Most current evidence suggests that obstructive apnea results from an interaction of the anatomy of the upper airway with the control of pharyngeal dilator muscles. 4 Afflicted patients have compromised pharyngeal anatomy with reduced airway lumen. 16-19,20 Through reflex mechanisms that drive activation of dilator muscles, pharyngeal patency is well maintained during wakefulness. 21-23 However, these protective reflexes are diminished during sleep, thereby leading to collapse of the pharyngeal airway in anatomically predisposed people. 24 Thus, aging could predispose to apnea via changes in pharyngeal anatomy and biomechanics or via deterioration in the function of pharyngeal dilator muscles. 25-31 By combining magnetic resonance imaging techniques with pharyngeal physiological assessments, we sought to determine the structural and functional basis for the increased propensity for airway collapse among older persons. We included normal and near-normal controls to avoid the confounding influences of repetitive pharyngeal collapse as might occur with sleep apnea. METHODS Subjects Eighteen men and 20 women across a range of ages were enrolled (Table). The subjects were recruited using e-mail announcements and posters and through the Harvard Cooperative on Aging. Although some of our subjects had participated in prior studies, none of the agingrelated findings of the present study have been previously reported. The women under 50 were premenopausal based on regular menstrual cycles, whereas women over age 50 were postmenopausal for at least 2 years. All were free from comorbid conditions, including snoring and were taking no medications, based on a thorough history and physical examination by a pulmonary specialist. All provided informed consent for the protocol, which was approved by the Brigham and Women's Hospital Human Subjects' Committee. Equipment and Procedures Overnight Polysomnography-Patients were monitored for a minimum of 7 hours of sleep by electroencephalography, electromyography, electrooculography, nasal pressure, nasal and oral airflow by thermister, chest and abdominal wall motion using piezo electrodes, electrocardiography, anterior tibialis electromyography, and arterial oxygen saturation using Requests for reprints should be addressed to

Multiple sclerosis lesions show a propensity for frontal and parietal white matter. Lesion burden in these areas was strongly associated with performance on tasks requiring sustained complex attention and working verbal memory. This relationship was consistent over a 4-year period, suggesting that disruption of frontoparietal subcortical networks may underlie the pattern of neuropsychological impairment seen in many patients with MS.

Background-Structural MRI data indicate schizophrenics have reduced left-sided temporal lobe gray matter volumes, especially in the superior temporal gyrus (STG) and medial temporal lobe. Our data further suggest a specificity to schizophrenia spectrum disorders of STG volume reduction. Interpretation of research studies involving schizophrenics may be complicated by the effects of exposure to neuroleptics and chronic illness. Sharing the same genetic diathesis of schizophrenics, subjects with schizotypal personality disorder (SPD) offer a unique opportunity to evaluate commonalities between schizophrenia and SPD, particularly as SPD subjects are characterized by cognitive and perceptual distortions, an inability to tolerate close friendships, and odd behavior, but they are not psychotic and so have generally not been prescribed neuroleptics nor hospitalized. Evaluation of brain structure in SPD may thus offer insight into the "endophenotype" common to both disorders. In addition, differences between groups may suggest which are the brain structures of schizophrenics that contribute to the development of psychosis.