Anton N. Hasso

Children's Brain Development Benefits from Longer Gestation.

Disruptions to brain development associated with shortened gestation place individuals at risk for the development of behavioral and psychological dysfunction throughout the lifespan. The purpose of the present study was to determine if the benefit for brain development conferred by increased gestational length exists on a continuum across the gestational age spectrum among healthy children with a stable neonatal course. Neurodevelopment was evaluated with structural magnetic resonance imaging in 100 healthy right-handed 6- to 10-year-old children born between 28 and 41 gestational weeks with a stable neonatal course. Data indicate that a longer gestational period confers an advantage for neurodevelopment. Longer duration of gestation was associated with region-specific increases in gray matter density. Further, the benefit of longer gestation for brain development was present even when only children born full term were considered. These findings demonstrate that even modest decreases in the duration of gestation can exert profound and lasting effects on neurodevelopment for both term and preterm infants and may contribute to long-term risk for health and disease.

Cerebral vasoconstriction in toxemia

Three patients with toxemia developed acute neurologic deterioration postpartum. In all, cerebral angiography revealed widespread arterial vasoconstriction. Cerebral vasoconstriction may be an important cause of neurologic complications in toxemia.

CT and angiographic correlation of severe neurological disease in toxemia of pregnancy

SummaryTwo patients with severe cerebral symptoms of toxemia of pregnancy were examined using computed tomography (CT) and angiography. CT disclosed extensive areas of low attenuation within the cerebral hemispheres. Angiography revealed constriction and narrowing of proximal and peripheral vessels suggesting vasculitis with extensive areas of impaired regional cerebral blood flow. A review of the known pathology and the theories regarding the pathophysiology of the cerebral effects of toxemia is presented.

Susceptibility-weighted imaging for differential diagnosis of cerebral vascular pathology: A pictorial review

Susceptibility-weighted imaging (SWI) is a high-spatial resolution, three-dimensional, gradient-echo (GRE) magnetic resonance (MR) technique. This fully velocity-compensated pulse sequence utilizes the magnetic susceptibility differences of various tissues or substances, such as blood products, iron, and calcification. By postprocessing the magnitude images using a phase mask, it emphasizes the magnetic properties of different susceptibility effects. Generated minimal intensity projection (minIP) images can further demonstrate tortuous vasculature and the continuity of vessels or abnormalities across slices. SWI has been used to improve the diagnosis of neurological trauma, brain neoplasm, neurodegenerative disorders, and cerebrovascular disease because of its ability to demonstrate microbleeds and conspicuity of the veins and other sources with susceptibility effects. We have used SWI to identify cerebrovascular lesions which may be obscured on other MR sequences to aid in the differential diagnosis. We present a review with selected cases to demonstrate the usefulness of this new neuroimaging technique in improving the diagnosis of cerebral vascular pathology.

Stroke care delivery before vs after JCAHO stroke center certification

In 2004, the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) began certifying primary stroke centers.1 Certification requires adoption of guidelines,2 including standardized performance measures. The University of California Irvine Medical Center (UCIMC) was in the initial group of five hospitals certified, in January 2004. UCIMC is the only Level 1 trauma center and the only university medical center in Orange County, California, the fifth most populous US county.3 The hospital has 462 beds, a 7-bed neuroscience intensive care unit, and a 15-bed intermediate stroke care unit. In this report, we describe trends in stroke care delivery for the 1.5 years after JCAHO stroke center certification at UCIMC, compared with the previous 2.5 years. With JCAHO stroke center certification, the process of stroke care delivery changed at many levels. Before certification, neither a stroke team nor a stroke care unit was present at our center. Stroke care was generally administered according to the judgment of each physician, e.g., during acute evaluation, acute therapy selection, diagnostic workup, and prevention. After certification, numerous aspects of stroke care were standardized. Examples include an integrated response to emergency department brain attack codes, use of specific …

A Novel, Noninvasive, Predictive Epilepsy Biomarker with Clinical Potential

A significant proportion of temporal lobe epilepsy (TLE), a common, intractable brain disorder, arises in children with febrile status epilepticus (FSE). Preventative therapy development is hampered by our inability to identify early the FSE individuals who will develop TLE. In a naturalistic rat model of FSE, we used high-magnetic-field MRI and long-term video EEG to seek clinically relevant noninvasive markers of epileptogenesis and found that reduced amygdala T2 relaxation times in high-magnetic-field MRI hours after FSE predicted experimental TLE. Reduced T2 values likely represented paramagnetic susceptibility effects derived from increased unsaturated venous hemoglobin, suggesting augmented oxygen utilization after FSE termination. Indeed, T2 correlated with energy-demanding intracellular translocation of the injury-sensor high-mobility group box 1 (HMGB1), a trigger of inflammatory cascades implicated in epileptogenesis. Use of deoxyhemoglobin-sensitive MRI sequences enabled visualization of the predictive changes on lower-field, clinically relevant scanners. This novel MRI signature delineates the onset and suggests mechanisms of epileptogenesis that follow experimental FSE.

Sequence-specific MR Imaging Findings That Are Useful in Dating Ischemic Stroke

Patients may present to the hospital at various times after an ischemic stroke. Many present weeks after a neurologic deficit has occurred, as is often the case with elderly patients and those in a nursing home. The ability to determine the age of an ischemic stroke provides useful clinical information for the patient, his or her family, and the medical team. Many times, perfusion imaging is not performed, and pulse sequence-specific magnetic resonance (MR) imaging findings may help determine the age of the infarct. The findings seen at apparent diffusion coefficient mapping and diffusion-weighted, fluid-attenuated inversion recovery (FLAIR) and unenhanced and contrast material-enhanced T1- and T2-weighted gradient-echo and susceptibility-weighted MR imaging may help determine the relative age of a cerebral infarct. Strokes may be classified and dated as early hyperacute, late hyperacute, acute, subacute, or chronic. Recent data indicate that in many patients with restricted diffusion and no change on FLAIR images, it is more likely than was initially thought that the stroke is less than 6 hours old. The time window to administer intravenous tissue plasminogen activator is currently 4.5 hours from the time when the patient was last seen to be normal, and for anterior circulation strokes, the time window for administering intraarterial tissue plasminogen activator is 6 hours from when the patient was last seen to be normal. For this reason, accurate dating is important in patients with ischemic stroke.

Occlusion of the intradural vertebrobasilar artery

SummaryThe diagnosis of occlusion of the intradural vertebrobasilar artery (OIDVBA) was made by means of cerebral angiography in 22 patients. The clinical presentation, course and followup were studied in conjunction with the angiographic findings in each case and the following conclusions made. OIDVBA is not rare. It occurs one-fourth as often as occlusion of the carotid artery. The correct diagnosis is not made clinically before angiography in the majority of patients. Complete visualization of the neck and intracranial vasculature is necessary to document the occlusion. Atherosclerotic thrombosis is the most common type of occlusive lesion. The most common predisposing factors are atherosclerosis, hypertensive cardiovascular disease, diabetes mellitus, and developmental vertebrobasilar hypoplasia. Most patients with occlusion are in the 7th and 8th decades of life and transient attacks of vertebrobasilar ischemia precede the occlusion in one-half of the cases. Emboli usually lodge in the terminal portion of the basilar artery whereas thrombotic occlusions tend not to be located in a characteristic segment. A majority of patients diagnosed angiographically survive their OIDVBA, but most distal occlusions result in death, often following several weeks of coma. In the surviving majority, disturbance of gait, impairment of vision, and symptoms of transient vertebrobasilar ischemia are the most common sequelae.

Orbital Vascular Anatomy and Embryology

Serial direct magnification angiography enhances detailed orbital vasculature apart from the surrounding vessels and aids in the diagnosis of orbital neoplasms. Selective techniques show branches of the internal and external carotid arteries supplying the orbit and their important anastomotic channels. The dual blood supply to the orbit is structured on embryological origins.

Cortical and subcortical changes in typically developing preadolescent children

There is evidence that abnormal cerebral development during childhood is a risk factor for various cognitive and psychiatric disorders. There is not, however, sufficient normative data available on large samples of typically developing children, especially within the narrow preadolescent age range. We analyzed high resolution MRI images from 126 normally developing children between ages 6 and 10 years. Age related differences in cortical thickness and in the volumes of major subcortical structures were assessed. Thinner cortices were observed in the occipital, parietal and somatosensory regions as well as in distinct regions of the temporal and frontal lobes with increasing age. Among the major subcortical structures analyzed in this study, only the thalamus showed increased volume with age after accounting for intracranial volume. Within the age range studied age-related cortical and subcortical differences were similar for boys and girls except for the right insula, where girls showed a slight increase in thickness with age. The findings reveal age-associated changes in brain anatomy, providing information about the trajectory of normal brain development during late childhood.