David B. Hinshaw

Acute gastric volvulus: A study of 25 cases☆

Twenty-five patients with acute gastric volvulus were studied. The two types, organoaxial and mesenteroaxial, are compared with respect to clinical characteristics, diagnosis, pathogenesis and treatment. An understanding of the varied features, including both thoracic and abdominal manifestations, is essential to early recognition and prompt treatment. In addition to Borchardts triad, this study suggests three important features: (1) minimal abdominal findings when the stomach is in the thorax; (2) a gas-filled viscus in the lower chest or upper abdomen shown by chest radiography (Figure 8), and (3) obstruction at the site of volvulus shown by emergency upper gastrointestinal series. The high incidence of strangulation (28 percent) in this series attests to the urgency of this condition and is a compelling reason for the elective repair of paraesophageal hiatal hernias whenever possible.

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.

Predictive value of proton magnetic resonance spectroscopy in pediatric closed head injury

We studied 26 infants (1-18 months old) and 27 children (18 months or older) with acute nonaccidental (n = 21) or other forms (n = 32) of traumatic brain injury using clinical rating scales, a 15-point MRI scoring system, and occipital gray matter short-echo proton MRS. We compared the differences between the acutely determined variables (metabolite ratios and the presence of lactate) and 6- to 12-month outcomes. The metabolite ratios were abnormal (lower NAA/Cre or NAA/Cho; higher Cho/Cre) in patients with a poor outcome. Lactate was evident in 91% of infants and 80% of children with poor outcomes; none of the patients with a good outcome had lactate. At best, the clinical variables alone predicted the outcome in 77% of infants and 86% of children, and lactate alone predicted the outcome in 96% of infants and 96% of children. No further improvement in outcome prediction was observed when the lactate variable was combined with MRI ratios or clinical variables. The findings of spectral sampling in areas of brain not directly injured reflected the effects of global metabolic changes. Proton MRS provides objective data early after traumatic brain injury that can improve the ability to predict long-term neurologic outcome.

Prognostic value of 1H-MRS in perinatal CNS insults

The authors studied 37 term neonates (38-42 gestational weeks) at 1-11 days after central nervous system insult to determine whether proton magnetic resonance spectroscopy (1H-MRS) of the occipital gray/parietal white matter was useful in predicting outcomes. Etiologies included asphyxia, 18; sepsis/meningitis, 8; metabolic disorders, 5; stroke, 4; and trauma, 2. 1H-MRS data (1.5T; 8 cm3 vol, stimulated echo acquisition mode sequence, TE = 20 ms, TR = 3000 ms) were expressed as metabolite peak area ratios (NAA/Cr, NAA/Cho, Cho/Cr) and the presence or absence of lactate. Outcomes were assessed at 6 to 12 months post-insult using the Pediatric Cerebral Performance Scale and were dichotomized as follows: good/moderate outcome (good, mild or moderate disability) or poor outcome (severe disability, persistent vegetative state, death). Neonates with poor outcomes had significantly lower NAA/Cho and significantly higher Cho/Cr ratios in the occipital region, as compared with patients with good/moderate outcomes. No neonates with good/moderate outcomes had metabolite ratios that exceeded 2 standard deviations from the mean. In addition, the absence of lactate on 1H-MRS correlated with a good/moderate outcome. The study also showed that 1H-MRS metabolite ratio data, added to either the Sarnat or EEG scores, enhanced the correlation between these prognostic factors and outcomes. 1H-MRS provides additional objective data early after a wide variety of perinatal neurologic insults to enhance outcome prediction.

Intimal injury from arterial clamps

Preliminary experimental data have been presented indicating that intimal injury of some degree is a virtually constant finding at the site of application of any arterial occluding clamp. These injuries vary from intimal distortion to complete fracture into the media of the vessel. The degree of injury appears directly proportional to the amount of pressure exerted through a given clamp. Atherosclerotic arteries are particularly subject to severe degrees of intimal injury. Preliminary observations suggest that heparin is not helpful in preventing platelet aggregation and initial thrombus formation at intimal injury sites. The problem of anticoagulation at such injury sites is being studied further.

Proton MR spectroscopy in children with acute brain injury: comparison of short and long echo time acquisitions.

The aim of this study was to evaluate comparatively the information given by proton magnetic resonance spectroscopy (MRS) with short echo time (TE 20 msec) stimulated echo acquisition mode and long TE (270 msec) point‐resolved spectroscopy in predicting long‐term outcome in children suffering from acute brain injury. At 1.5 T, we performed single‐voxel proton MRS with both methods in occipital gray matter of 70 children. A linear discriminant analysis used to predict outcomes based on MRS variables was compared with actual neurologic outcome assigned at least 6 months after injury by a pediatric neurologist. Using peak area metabolite ratios and lactate presence, the short and long TE methods were equally predictive in children over 1 month of age. In neonates less than 1 month of age, the long TE method produced a higher percentage of correct outcome predictions (91%) than the short TE method (79%). The long TE method detected lactate more often in all age groups. J. Magn. Reson. Imaging 2000;11:9–19.

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.

Proton magnetic resonance spectroscopy in children with acute central nervous system injury

Single voxel proton magnetic resonance spectroscopy (1H-MRS) was used in 30 infants and children with acute central nervous system injuries to determine the value of changes in specific metabolite ratios in predicting outcome. The mean age of all patients was 38 +/- 52 months and the mean time of study after insult was 7 +/- 5 days. 1H-MRS was determined in the occipital gray and parietal white matter (8 cm3 volume, STEAM sequence with TE = 20 ms, TR = 3,000 ms). Data were expressed as ratios of different metabolite peak areas including N-acetylaspartate (NA), choline-containing compounds (Ch), creatine and phosphocreatine (Cr), and lactate (Lac). Statistically significant differences were observed when patients with good/moderate (G/M) outcomes (n = 17; mean age: 46 months) were compared to patients with bad outcomes (n = 10; mean age: 26 months). NA/Cr and NA/Ch were significantly lower in the bad outcome group (NA/Cr = 1.15 +/- 0.38; NA/Ch = 1.18 +/- 0.52) compared to the G/M group (NA/Cr = 1.41 +/- 0.28, P < .05; NA/Ch = 1.98 +/- 0.81, P < .01). Lactate was present in 80% of bad outcome patients and in none of the G/M group (P < .0001). Using a linear discriminant analysis and combining 4 clinical variables (Glasgow Coma Scale score, initial pH and glucose, number of days unconscious at time of 1H-MRS) allows classification of 94% of patients into their correct outcome group. Use of spectroscopy variables (NA/Cr, NA/Ch, Ch/Cr, presence of lactate) alone correctly classified 81% of patients. The combination of clinical and 1H-MRS variables correctly classified 100% of patients. Our findings suggest that 1H-MRS adds information which, in combination with clinical examination, may be useful in outcome assessment in children with serious acute central nervous system injury.

Proton magnetic resonance spectroscopy in the evaluation of children with congenital heart disease and acute central nervous system injury

We studied nine infants and children, aged 1 week to 42 months, with severe acute central nervous system injuries associated with cardiac disease or corrective operations by means of single-voxel proton magnetic resonance spectroscopy to determine whether this technique would be useful in predicting neurologic outcome. Proton magnetic resonance spectroscopic data were acquired from the occipital gray and parietal white matter (8 cm3 volume, stimulated echo-acquisition mode sequence with echo time of 20 msec and repetition time of 3.0 seconds) a median of 9 days after operation (range 3 to 42 days). Data were expressed as ratios of areas under metabolite peaks, including N-acetyl compounds, choline-containing compounds, creatine and phosphocreatine, and lactate. Four patients had cerebral insults before operation, one had both a preoperative and a perioperative insult, three had perioperative insults, and one had a prolonged cardiac arrest 2 days after operation. Outcomes (Glasgow Outcome Scale scores) were assigned at discharge and 6 to 12 months after injury. Six patients were in a vegetative state or had severe impairment at discharge, and two still had severe impairment at 6- to 12-month follow-up. Proton magnetic resonance spectroscopy showed lactate in these two patients, along with markedly reduced ratios of N-acetyl compounds to creatine compounds. The other four patients with severe impairment recovered to a level of mild disability at follow-up. Proton magnetic resonance spectroscopy showed no lactate in these four patients; however, one patient showed moderately reduced ratio of N-acetyl compounds to creatine compounds. The three patients who had mild or moderate impairment at discharge showed no lactate and mild or no changes in metabolite ratios; follow-up revealed normal or mild outcomes. Overall, we found that the presence of lactate and markedly reduced ratios of N-acetyl compounds to creatine compounds were predictive of severe outcomes at discharge and long-term follow-up, whereas no lactate and mild or no changes in ratios suggested potential for recovery with at least a mild disability. Continuing investigations are in progress to determine the optimal selection of candidates and timing of proton magnetic resonance spectroscopic studies.

Transcatheter embolization facilitating surgical management of a giant inferior gluteal artery pseudoaneurysm

This article is a report on a case of a giant pseudoaneurysm of the inferior gluteal artery where important features of the diagnosis, with special mention of magnetic resonance imaging and arteriography, are discussed. Surgical therapy is the treatment of choice for these lesions. Historically, proximal arterial control has been the main dilemma in the management of gluteal artery pseudoaneurysm. We found transcatheter embolization to provide optimal control and eliminate the need for preperitoneal or intraabdominal dissection. Surgical repair can then be carried out without risk of intraoperative hemorrhage.