Acute brain MRI findings in 120 Malawian children with cerebral malaria: new insights into an ancient disease.

BACKGROUND AND PURPOSE: There have been few neuroimaging studies of pediatric CM, a common often fatal tropical condition. We undertook a prospective study of pediatric CM to better characterize the MRI features of this syndrome, comparing findings in children meeting a stringent definition of CM with those in a control group who were infected with malaria but who were likely to have a nonmalarial cause of coma. MATERIALS AND METHODS: Consecutive children admitted with traditionally defined CM (parasitemia, coma, and no other coma etiology evident) were eligible for this study. The presence or absence of malaria retinopathy was determined. MRI findings in children with ret+ CM (patients) were compared with those with ret- CM (controls). Two radiologists blinded to retinopathy status jointly developed a scoring procedure for image interpretation and provided independent reviews. MRI findings were compared between patients with and without retinopathy, to assess the specificity of changes for patients with very strictly defined CM. RESULTS: Of 152 children with clinically defined CM, 120 were ret+, and 32 were ret-. Abnormalities much more common in the patients with ret+ CM were markedly increased brain volume; abnormal T2 signal intensity; and DWI abnormalities in the cortical, deep gray, and white matter structures. Focal abnormalities rarely respected arterial vascular distributions. Most of the findings in the more clinically heterogeneous ret- group were normal, and none of the abnormalities noted were more prevalent in controls. CONCLUSIONS: Distinctive MRI findings present in patients meeting a stringent definition of CM may offer insights into disease pathogenesis and treatment.

Magnetic resonance imaging in Malawi: contributions to clinical care, medical education and biomedical research.

Advanced medical imaging technologies are generally unavailable in low income, tropical settings despite the reality that neurologic disorders are disproportionately common in such environments. Through a series of donations as well as extramural research funding support, an MRI facility opened in Blantyre, Malawi in July 2008. Resulting opportunities for studying common tropical disorders, such as malaria and schistosomiasis, in vivo are promising. The subsequent improvements in local patient care were expected and exceptional and include major revisions in basic care protocols that may eventually impact care protocols at facilities in the region that do not have recourse to MRI. In addition, advanced neuroimaging technology has energized the medical education system, possibly slowing the brain drain. Advanced technologies, though potentially associated with significant fiscal opportunity costs, may bring unexpected and extensive benefits to the healthcare and medical education systems involved.

Assessment of aspiration risk in stroke patients with quantification of voluntary cough.

BACKGROUND: Dysphagia and subsequent aspiration are serious complications of acute stroke that may be related to an impaired cough reflex. It was hypothesized that aspirating stroke patients would have impaired objective measures of voluntary cough as compared with both nonstroke control subjects and nonaspirating stroke patients. METHODS: Swallowing was evaluated by standard radiologic or endoscopic methods, and stroke patients were grouped by aspiration severity (severe, n = 11; mild, n = 17; no aspiration, n = 15). Airflow patterns and sound pressure level (SPL) of voluntary cough were measured in stroke patients and in a group of normal control subjects (n = 18). Initial stroke severity was determined retrospectively with the Canadian Neurological Scale. RESULTS: All cough measures were altered in stroke patients as a group relative to nonstroke control subjects. Univariate analysis showed that peak flow of the inspiration phase (770.6 +/- 80.6 versus 1,120.1 +/- 148.4 mL/s), SPL (90.0 +/- 3.1 versus 100.2 +/- 1.6 dB), peak flow of the expulsive phase (875.1 +/- 122.7 versus 1,884.1 +/- 221.6 mL/s), expulsive phase rise time (0.34 +/- 0.1 versus 0.09 +/- 0.01 s), and cough volume acceleration (5.5 +/- 1.3 versus 27.8 +/- 3.9 mL/s/s) were significantly impaired in severe aspirators as compared with nonaspirators. Aspirating patients had more severe strokes than nonaspirators (mean Canadian Neurological Scale score 7.7 +/- 0.7 versus 9.8 +/- 0.3). Multivariate logistic regression found only expulsive phase rise time values during cough correlated with aspiration status. CONCLUSION: Objective analysis of cough may provide a noninvasive way to identify the aspiration risk of stroke patients.

Racial variation in initial stroke severity.

BACKGROUND AND PURPOSE: Blacks experience greater morbidity and mortality from stroke than do whites. The degree to which this is due to the severity of the initial stroke is not known. The objective of this study is to determine whether there is a racial difference in initial stroke severity. METHODS: A secondary analysis of a prospective cohort of 984 veterans (29.7% black) admitted to any of 9 geographically diverse Veterans Administration Hospitals for acute stroke between April 1995 and March 1997 was performed. Initial stroke severity was ascertained by using the modified Canadian Neurological Scale (CNS) applied retrospectively to medical record data. Stroke severity, unadjusted and adjusted for covariates, was compared between black and white patients. RESULTS: Blacks had greater initial stroke severity than did whites (mean CNS score 7.96 versus 8.32, respectively; P=0.039), with a 0.5-point difference on the scale corresponding to a single-level decrement in either speech or strength of half of an extremity. This difference persisted with adjustment for other important predictors of stroke severity (P=0. 035). However, there was no significant racial difference in severity when CNS scores were collapsed into a priori clinically relevant categories. CONCLUSIONS: Compared with whites, blacks show greater severity of stroke at hospital admission. It remains uncertain whether the relatively small but significant difference at presentation fully explains the striking racial differences in morbidity and mortality from stroke.

Isolated angiitis of the CNS presenting as subarachnoid haemorrhage.

Isolated angiitis of the CNS (IACNS) commonly presents with recurrent ischaemic or haemorrhagic infarcts, but subarachnoid haemorrhage is rare. Three patients with IACNS and subarachnoid haemorrhage are reported. Florid granulomatous angiitis with Langhans and foreign body type giant cells was found at necropsy in a child with sudden death. In two other patients the diagnosis was made angiographically. In one patient multifocal infarcts on MRI became evident one week after subarachnoid haemorrhage despite initial treatment with prednisone. Subarachnoid haemorrhage may be the first presentation of IACNS. Characteristic radiographic findings may allow early diagnosis.

T1-weighted MR imaging of the brain using a fast inversion recovery pulse sequence.

The purpose of this paper was to develop and evaluate a fast inversion recovery (FIR) technique for T1-weighted MR imaging of contrast-enhancing brain pathology. The FIR technique was developed, capable of imaging 24 sections in approximately 7 minutes using two echoes per repetition and an alternating echo phase encoding assignment. Resulting images were compared with conventional T1-weighted spin echo (T1SE) images in 18 consecutive patients. Compared with corresponding T1SE images, FIR images were quantitatively comparable or superior for lesion-to-background contrast and contrast-to-noise ratio (CNR). Gray-to-white matter and cerebrospinal fluid (CSF)-to-white matter contrast and CNR were statistically superior in FIR images. Qualitatively, the FIR technique provided comparable lesion detection, improved lesion conspicuity, and superior image contrast compared with T1SE images. Although FIR images had greater amounts of image artifacts, there was not a statistically increased amount of interpretation-interfering image artifact. FIR provides T1-weighted images that are superior to T1SE images for a number of image quality criteria.

Initial clinical experience in MR imaging of the brain with a fast fluid-attenuated inversion-recovery pulse sequence.

PURPOSE: To evaluate fast fluid-attenuated inversion-recovery (FLAIR) technique for imaging brain abnormalities. MATERIALS AND METHODS: A fast FLAIR sequence was developed that provided 36 5-mm contiguous sections in 5 minutes 8 seconds. Resulting images were compared with dual-echo T2-weighted spin-echo images of 41 consecutive patients with brain abnormalities. RESULTS: Contrast and contrast-to-noise ratios (C/Ns) (for contrast between the lesion and background and between the lesion and cerebrospinal fluid) for fast FLAIR exceeded the corresponding values for T2-weighted spin-echo images for all but the second-echo lesion-to-background C/N. Fast FLAIR provided equivalent or greater overall lesion conspicuity and enabled greater lesion detection in 98% and 100%, respectively, of the evaluations. Fast FLAIR images more often had image artifact, but this did not interfere with image interpretation in a significantly (P < or = .05) greater number of evaluations. CONCLUSION: Fast FLAIR provides images that are superior to proton-density- and T2-weighted images for many image quality criteria.

Pharyngoesophageal barotrauma in children: a report of six cases.

Pharyngeal and pharyngoesophageal penetrating injury occurred in six children following the explosive discharge of compressed carbon dioxide into their mouths. The gas was contained in plastic, screw-cap soft-drink containers overpressurized by the addition of dry ice. Three children were managed surgically and three conservatively. All recovered fully, and at follow-up of from 3 to 52 months, swallowing is normal.

Retrosternal gastric bypass for inoperable esophageal cancer: a report of 71 patients.

Palliative substernal gastric bypass was performed in 71 patients with unresectable cancer of the intrathoracic esophagus. Fifty-six patients (78.9%) left the hospital, 53 eating normally and 3 on a soft diet. There were 15 hospital deaths (21%), 8 due to respiratory failure and pulmonary sepsis with tracheoesophageal fistulization. The remaining 7 deaths were due to aspiration and respiratory failure in 2 patients, anastomotic leakage with sepsis in 2, subphrenic abscess and septicemia in 1, mediastinitis in 1, and intestinal obstruction in 1. Anastomotic leakage occurred in 17 patients (23.9%), 5 of whom died. Wound infections developed in 28 patients (39.4%), 3 with mediastinal esophagocutaneous fistulas. Reestablishment of unimpeded swallowing, relief of respiratory aspiration, isolation of cancerous tracheobronchial infiltration, and freedom from incident-prone endoesophageal tubes were achieved in all patients leaving the hospital. Information is presented on 25 patients who were available for follow-up.

Analbuminemia in an American Indian girl.

Analbuminemia was fortuitously detected in a nonedematous 12-year-old American Indian girl with atopic dermatitis, mild bronchial asthma, a mild seizure disorder, and hyperlipoproteinemia with a corneal arcus. Immunologic methods revealed trace amounts (17 mg/100 ml) of apparently normal serum albumin. The patient's parents were remotely related. The pedigree and clinical findings were compatible with autosomal recessive transmission of analbuminemia. Heterozygotes had subnormal levels of serum albumin. The Gc-locus is closely linked to the structural albumin locus. Gc-protein levels were normal in the patient and together with normal chromosomal banding studies make it unlikely that a chromosomal deletion caused analbuminemia. Gc-types in the family were compatible with, but did not prove, linkage of analbuminemia to the Gc-locus. These findings suggest a "thalassemia"-like mutation for this disorder.