Hippocampal volume in women victimized by childhood sexual abuse.

BACKGROUND: Several prior studies have found reduced hippocampal volume in victims of psychological trauma with post-traumatic stress disorder (PTSD). We were interested to determine if this finding was evident in women who were victimized by severe sexual abuse in childhood. METHODS: In this study, hippocampal volume was measured using quantitative magnetic resonance imaging (MRI) in 21 women who reported being severely sexually abused in childhood and 21 socio-demographically similar women without abuse histories. RESULTS: Women who reported sexual victimization in childhood had significantly reduced (5% smaller) left-sided hippocampal volume compared to the non-victimized women. Hippocampal volume was also smaller on the right side, but this failed to reach statistical significance. Left-sided hippocampal volume correlated highly (rs = -0.73) with dissociative symptom severity, but not with indices of explicit memory functioning. CONCLUSIONS: These findings, which are generally consistent with prior reports of reduced hippocampal volume in combat veterans with PTSD, suggest that diminished hippocampal size may be either a consequence of trauma exposure or a risk factor for the development of psychiatric complications following trauma exposure. The observed relationship between symptom severity and hippocampal volume suggests that mesial temporal lobe dysfunction may directly mediate certain aspects of PTSD and dissociative disorder symptomatology.

Structural brain changes in PTSD. Does trauma alter neuroanatomy?

Although the impetus for studying hippocampal morphology and functioning in PTSD was the finding that stress could result in hippocampal damage in rodent and primate models, it is far from proven that the findings to date in PTSD represent defects that have been caused by trauma. It is equally possible that the findings represent a preexisting anomaly which might serve as a risk factor for the development of PTSD following trauma exposure. To resolve this dilemma, it is necessary to study persons at high risk for trauma (e.g., soldiers) prior to trauma exposure and ag in after exposure. Such methods will permit the determination not only of whether trauma alters hippocampal morphology, but also, if so, of whether this effect is limited to persons with PTSD. At the present time, the field would be well advised to proceed vigorously but with appropriate caution along these lines of research. As just outlined, sample sizes have been small, and potentially confounding variables have abounded in most studies. The next few years of research may well continue to replicate the finding of abnormal hippocampal morphology in PTSD. However, it would not be surprising to find that other brain regions are also involved and that these represent part of a broader risk spectrum for the development of psychopathology under stress. Until these issues are clarified, the neuroanatomical findings to date in PTSD should be viewed as tentative, tantalizing, and in need of additional study.

Influence of magnetic resonance imaging on diagnosis and therapeutic intention.

RATIONALE AND OBJECTIVES: We assessed the contribution of magnetic resonance (MR) imaging to diagnostic and therapeutic decision making. METHODS: In a before-after observational study, we collected information from clinicians before and after patients were given MR examinations. We studied 406 cases selected from consecutive referrals to a single MR imaging facility in Manitoba between November 1, 1991, and October 30, 1992, for diagnosis of suspected brain, spinal column, or large-joint disorder. We examined changes in diagnoses, changes in clinician diagnostic confidence, and changes in therapeutic intentions after MR examinations. RESULTS: Overall, MR imaging findings contributed to a change in referring physicians' diagnoses or diagnostic confidence in 76% of the cases. Referring physicians reported a change in provisional diagnosis in 42% of the cases. In 67% of these cases, the referring physician's provisional diagnosis was ruled out by normal examination findings; in the remaining 33% of the cases, an alternate diagnosis was offered by the consulting radiologist. In the 58% of the cases in which the provisional diagnosis was not altered by MR imaging findings, clinical confidence in the provisional diagnosis increased in 46% of the cases and decreased in 12% of the cases. Management plans were reported to be altered in 54% of the cases; in 24% of the cases, therapeutic intentions changed from lower to higher levels of intervention. CONCLUSION: Although MR imaging had a substantial influence on clinicians' decisions concerning diagnoses, the influence of MR imaging findings on therapeutic decision making, and therefore on patients' health status, was more moderate.

A choroid plexus papilloma arising from an incidental pineal cyst.

We report a case of an incidental pineal cyst discovered on MR imaging that progressed to a choroid plexus papilloma. The MR features of pineal cysts, the difficulty of distinguishing benign cysts from cystic neoplasms, and the implications for surgical management are discussed.

Diagnostic imaging management in Manitoba: 1995-2000.

As part of a 5-year imaging management plan being developed for the single insurance carrier in Manitoba, the radiologic utilization for the province was reviewed. For the fiscal year 1993 (April 1, 1992, through March 31, 1993), 1,056,694 imaging studies were performed in a total patient population of 1,133,117 in 81 hospitals and 39 offices in which 648 units of equipment were operated by 773.4 full-time personnel at a cost of $100,302,812 ($75,227,109 in U.S. dollars). The skin dose for the total population for the year was 40,112 Gy, compared with 35,513 Gy in 1979. Since 1979, there has been a 9% increase in the number of radiologic examinations (from 972,426 examinations), a greater need for more personnel to conduct ultrasound, mammography, computed tomography, and magnetic resonance imaging examinations, and striking costs escalation (from $25,082,500 to $100,302,812). Reduction of total funding for imaging services will be possible only if the medical service infrastructure and physician behavior are altered, since imaging is a support service. Hospital services must be integrated and the infrastructure reduced, and physicians must adhere to guidelines and practice protocols for requesting consultations.

The influence of referral protocols on the utilization of magnetic resonance imaging: evidence from Manitoba.

The relative scarcity of magnetic resonance imaging (MRI) capacity in most Canadian jurisdictions has created pressures to develop guidelines on appropriate clinical indications for examination by this method. The objective of this study was to assess the influence of referral protocols on the utilization of MRI services. Three neuroradiologists and one radiologist reviewed the indications for MRI for 198 referrals to the facility at St. Boniface General Hospital in Winnipeg (99 from outside Manitoba and 99 from within the province), selected at random from patients seen between Jan. 1 and Dec. 31, 1991, for suspected disorder of the brain or the spine. Out-of-province referrals had not been subject to referral protocols, whereas those from within Manitoba had been subject to such protocols. At least three of the four radiologists agreed on whether an examination was appropriate in 175 of the 198 cases (88.4%). Out-of-province referrals were significantly more likely to be considered inappropriate for MRI: 24 (24%) of the referrals from outside Manitoba were judged inappropriate by three or more reviewers, whereas only 10 (10%) of the referrals from within Manitoba were judged inappropriate (chi 2, p < 0.01). Of the 19 cases that were judged inappropriate for MRI by three or more reviewers and that yielded abnormal findings, unique clinical information was derived from the examination in only 1 (5%); in contrast, of the 85 cases that were judged appropriate for MRI by three or more reviewers and that yielded abnormal findings, unique information was found in 47 (55%).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography of encephalomyosynangiosis and superficial temporal artery to middle cerebral artery anastomosis in moyamoya disease.

The authors present an angiographic follow-up of anastomotic surgery (extra- to intracranial) in a 33-year-old woman with moyamoya disease. The bypass was superficial-temporal to middle-cerebral, with placement of muscle tissue over the open craniotomy; the bypass eventually regressed.

A simplified method for measuring cerebral blood flow with xenon-enhanced computed tomography.

The measurement of cerebral blood flow using the xenon-enhanced computed tomography (XECT) technique requires that the build-up of xenon in both brain tissue and end-tidal expired air be determined as a function of time. Monitoring of the former is carried out using CT scanning and the latter, most often, using a thermoconductivity analyser or mass spectrometer. This paper examines the possibility of greatly simplifying the XECT technique by eliminating the need for either thermoconductivity analyser or mass spectrometer. In the proposed approach, the patient's expired air is channelled through the scan field using a flexible plastic tube and sampled by the CT scanner in conjunction with the build-up of xenon in brain tissue. Phantom measurements have demonstrated the ability of the CT scanner to detect variations in the xenon concentration in expired air while computer simulations have shown that errors arising as a result of the proposed methodology are small compared to other inherent sources in the XECT technique.

Routine contrast enhancement for cranial magnetic resonance imaging: an analysis of its diagnostic value in adults.

This study evaluated the diagnostic value of contrast enhancement in consecutive adults referred for cranial magnetic resonance imaging (MRI). All of the 112 participating patients underwent two sets of studies, first without and then with a contrast medium. Three neuroradiologists independently reviewed the information for each patient. Contrast enhancement contributed diagnostically useful information in 75% of cases: in 4% because undiagnosed lesions became apparent, in 26% because more information was obtained regarding the size, extent or margins of a lesion and in 45% because the lack of contrast enhancement in the area of interest allowed more confident exclusion of disease in patients with compelling clinical findings or demonstrated the nonaggressive nature of a lesion apparent with unenhanced MRI. The authors conclude that contrast enhancement is diagnostically useful for most patients referred for cranial MRI. Although the proportion of cases in which contrast enhancement was useful was much higher than in previous studies conducted in the United States, the authors believe that this finding is due to the high prevalence of disease in the population referred to this Canadian MRI centre.

Phenotypic variability in glutaric aciduria type I: Report of fourteen cases in five Canadian Indian kindreds.

We describe 14 patients with glutaric aciduria type 1 in five Canadian Indian kindreds living in Manitoba and northwest Ontario. The patients had marked clinical variability of the disease, even within families. Eight followed the typical clinical course of normal early growth and development until the onset of neurologic abnormalities, often precipitated by infection, between 6 weeks and 7 1/2 months of age. Five patients had early developmental delay; one was thought to be normal until 8 years of age. Three patients died, seven are severely mentally and physically handicapped, and four have only mild mental retardation or incoordination. Six patients had macrocephaly in the neonatal period. Computed tomography was done for 12 patients, and findings were abnormal in 11. Glutaric acid and 3-hydroxyglutaric acid were detected in increased amounts in the urine of all patients, but the concentrations were much lower than those in most other reported patients. Glutaryl coenzyme A dehydrogenase activity in skin fibroblasts, interleukin-2-dependent lymphocytes, or both, ranged from 0% to 13% of control values. There was no correlation between clinical severity and urine glutaric acid concentration or level of residual enzyme activity. We recommend that organic acid analysis of the urine be done in patients with unexplained cerebral palsy-like disorders, especially if the computed tomographic scan is abnormal. If there is suspicion of glutaric aciduria, glutaryl-coenzyme A dehydrogenase should be measured in fibroblasts or lymphocytes even if glutaric acid is not increased in the urine.

Quantitative computed tomography of the brain with xenon enhancement: a phantom study with the GE9800 scanner.

A recently proposed application of quantitative computed tomography is in the study of cerebral blood flow and partition coefficient using stable xenon as a freely diffusible, radio-opaque tracer. Central to the method is the calibration factor describing the relationship between CT number and xenon concentration in the brain. In this paper we examine the influence of temporal fluctuations, kVp, radial position and beam hardening on this calibration factor through the analysis of a series of phantom measurements. We conclude that under clinically realistic conditions and with correlations for temporal fluctuations, the error associated with the calibration factor is less than 2%. Furthermore, errors of this magnitude translate into errors of less than 3% in derived blood flow and partition coefficient values obtained using xenon-enhanced computed tomography.

The role of noise in the measurement of cerebral blood flow and partition coefficient using xenon-enhanced computed tomography.

Monte Carlo simulations have been used to study the accuracy which can be expected in the quantification of blood flow and the partition coefficient using xenon-enhanced computed tomography in the presence of noise. We have demonstrated that the markedly asymmetric frequency distribution of estimates increases in size rapidly with an increase in the standard error of the input CT data. On the basis of our results, we recommend that controllable sources of noise (eg. CT number drift) be corrected and that estimates be obtained by averaging CT data and then fitting, rather than averaging blood flow and partition coefficients derived from individual pixels, as the latter procedure results in the introduction of considerable bias.

Early metabolic and neurologic predictors of long-term quality of life after closed head injury.

Research has begun to identify early markers that predict survival after traumatic brain injury. In this study, trauma and biochemical indicators of severity were used to predict quality of life in 61 adults with traumatic brain injury and no damage to other organ systems. Severity markers available within 24 hours of injury were predictive of later psychosocial, behavioural and social role functioning. Multiple regression analyses demonstrated that the Glasgow Coma Scale, plasma glucose levels, leukocyte cell count and serum potassium concentration accounted for 12% to 66% of variance in certain measures of later quality of life. The importance of health-care resource allocation and psychosocial and behavioural intervention to the outcome after moderate traumatic brain injury is discussed.

CT-scan findings in an infant with glutaric aciduria type I.

An infant presented at three weeks of age with a rapidly enlarging head and hypertonicity. The diagnosis of glutaric aciduria type I (GAI) was confirmed by the absence of the enzyme glutaryl-CoA dehydrogenase in fibroblast culture. A CT scan at that time showed diffuse attenuation of cerebral white-matter. Scans at five and 10 months of age showed loss of white-matter volume and diffuse cerebral atrophy, most prominent in the frontal and temporal regions. GAI should be considered in the differential diagnosis of infants and children with neurological dysfunction who have CT-scan findings of white-matter attenuation and/or cerebral atrophy, most prominent in the frontal and temporal regions, and/or changes in the basal ganglia or thalamus.

Multiple intracerebral arteriovenous malformations. A case report and literature review.

The presence of multiple intracerebral arteriovenous malformations (AVMs) in a single patient has only been very rarely reported. We present a patient with three separate angiographically demonstrable intracerebral AVMs, all of which were radiologically demonstrated and surgically removed without residual neurological deficit. A literature survey was conducted and all the previously described cases of multiple intracerebral AVMs are discussed, along with the potential diagnostic and therapeutic implications.

CT and intracranial manifestations of otorhinologic disease.

Most inflammatory and neoplastic diseases of the ear, nose, nasopharynx, and paranasal sinuses have the capability of intracranial extension. CT is extremely important in defining such lesions, and surpasses complex motion tomography in delineating the extracranial soft tissue involvement and intracranial spread. Trauma can simultaneously affect both intracranial and extracranial compartments but because of its scope, is not dealt with in this submission.

Tropical diseases encountered in Canada: 1. Chagas' disease.

Chagas' disease, or South American trypanosomiasis, is an endemic South American disease now being seen in Canada in both acute and chronic forms. It is characterized by an initial parasitemia that elicits a brisk immune response. Evidence is mounting that the debilitating chronic form, which is characterized by cardiac and visceral organ failure, results from antigenic cross-reactivity between the parasite and the human host, which generates an aberrant, destructive, cell-mediated immune response. Diagnosis, treatment and potential areas for investigation are discussed.