Apolipoprotein-E and white-matter hyperintensities in late-life depression.

The authors conducted a follow-up study of 16 patients with late-life depression approximately 6 years after their initial assessment to evaluate the relationships between apolipoprotein-E (APO-E) status and white-matter hyperintensities (WMH). Ten patients had WMH at baseline, and four patients demonstrated an increase in WMH size over time. Three of four patients with the APO-E epsilon 4 allele demonstrated an increase in WMH over time, and only 1 of 12 patients without an epsilon 4 allele had an increase in WMH. Three of four patients with APO-E epsilon 4 allele developed a chronic course of major depression at follow-up. Patients with APO-E epsilon 4 had a higher number of depressive episodes and lower age at onset. APO-E may be a risk factor for cerebrovascular disease associated with late-life depression and may affect the clinical characteristics and disease course of depression.

Clinical and neuroradiologic features associated with chronicity in late-life depression.

The authors conducted a 6-year follow-up of 16 patients with late-life depression to evaluate the relationships between clinical and neuroradiologic variables and disease outcome. Patients had a comprehensive neuropsychiatric evaluation and magnetic resonance imaging (MRI) at baseline and follow-up. Eight of the 16 developed a chronic course of unremitting major depression sufficient to cause significant psychosocial impairment. Six patients with a chronic course and four patients with a non-chronic course of depression had white matter hyperintensities (WMH) on MRI at baseline. Four patients whose WMH increased in size over time developed a chronic unremitting course of depression. No patients with non-chronic depression had large areas of WMH at baseline or exhibited increased WMH size over time. Chronic depression was associated with severity of cerebrovascular risk factors, apathy, and poor quality of life. Treatment and prevention of cerebrovascular disease may improve the outcome of late-life depression.

Gender effects on persistent cerebral metabolite changes in the frontal lobes of abstinent cocaine users.

OBJECTIVE: Previous studies found functional changes in the frontal brain region and regions with projections to the frontal lobe in cocaine users. The aim of this study was to investigate persistent neurochemical changes in the frontal lobes of subjects with a history of crack cocaine dependence and to determine whether these changes are different in male and female users. METHOD: The frontal gray and white matter of 64 young asymptomatic and abstinent (> 5 months) cocaine users (34 male and 30 female) and 58 healthy comparison subjects without a history of drug abuse was evaluated with localized proton magnetic resonance spectroscopy (1H-MRS). RESULTS: Two-way analysis of variance showed significant cocaine effects on the concentration of frontal gray matter N-acetyl compounds, on the ratio of frontal white matter N-acetyl compounds to creatine levels, on frontal gray and white matter myoinositol levels, and on the ratio of myoinositol to creatine. Significant gender effects were observed for frontal gray matter choline-containing compounds, the ratio of choline-containing compounds to creatine, and the percentage of CSF in both gray and white matter. Interaction effects of cocaine and gender were observed for creatine, N-acetyl/creatine ratio, and myoinositol/creatine ratio in frontal white matter. CONCLUSIONS: Cocaine use is associated with neuronal injury (with decreased N-acetyl compounds) in the frontal cortex and glial activation (with increased myoinositol) in both frontal gray and white matter. In the frontal lobe, cocaine affects male users differently than female users. Future studies on the effects of cocaine abuse should control for the effects of gender-specific neurotoxicity.

Neuroimaging findings in twins discordant for Alzheimer's disease.

Data from computed tomography (CT) scans of 12 twin pairs in which one partner had Azheimer's disease (AD) and the other partner is cognitively intact were analyzed to study structural brain features associated with AD while controlling for familial factors. Visual ratings and analysis of quantified areas and volumes indicated that AD twins showed more dilation of temporal horns, lateral ventricles and third ventricle, and more atrophy of temporal lobes, particularly in the anterior temporal/perisylvian area, than their healthy cotwins. Demented twins did not have smaller intracranial areas or overall brain volumes than their intact partners. The apolipoprotein sigma-4 allele was associated with greater dilation of lateral ventricles and ventricular volume. Significant intrapair correlations were found for total intracranial area and volume, cerebellar area and white matter lesions.

Diagnostic imaging of the brain in acquired immunodeficiency syndrome (AIDS).

The central nervous system is commonly involved in acquired immunodeficiency syndrome (AIDS), resulting in a variety of lesions and diseases. They can be divided into the primary effects of human immunodeficiency virus (HIV), opportunistic infections, tumors, and vascular disease. This article is a review of the major imaging findings observed in each disease, with clinical and pathological correlations relevant to the goal of differential diagnosis.

Frontotemporal dementia and early Alzheimer disease: differentiation with frontal lobe H-1 MR spectroscopy.

PURPOSE: To evaluate cerebral biochemical abnormalities in patients with frontotemporal dementia and Alzheimer disease and to determine whether proton (hydrogen-1) magnetic resonance (MR) spectroscopy can help differentiate among these two patient groups and healthy (control) subjects. MATERIALS AND METHODS: MR imaging and H-1 MR spectroscopy were performed in 14 patients with frontotemporal dementia, 12 with probable Alzheimer disease (Alzheimer), and 11 healthy (control) elderly subjects. Spectra were acquired from midfrontal and temporoparietal gray matter with a double spin-echo sequence (repetition time, 3,000 msec; echo time, 30 msec). Results were expressed in metabolite concentrations corrected for the presence of cerebrospinal fluid. RESULTS: In frontotemporal dementia patients, the frontal lobe showed reduced N-acetyl compounds (-28%) and glutamate plus glutamine (-16%), suggestive of neuron loss, and increased myo-inositol (MI) (+19%), suggestive of increased glial content. In three frontotemporal dementia patients, a lactate peak was present in the frontal lobe. In Alzheimer patients, no statistically significant abnormalities were observed in the frontal region, but MI was elevated (+8%) in the temporoparietal region. With use of linear discriminant analysis of MR spectroscopy data alone, 92% of the frontotemporal dementia patients were correctly differentiated from the Alzheimer patients and control subjects. The overall accuracy for discrimination among all three groups was 84%. CONCLUSION: H-1 MR spectroscopy demonstrated biochemical abnormalities in patients with frontotemporal dementia and aided differentiation between patients with frontotemporal dementia and Alzheimer disease.

Aortic aneurysm morphology for planning endovascular procedures.

Endovascular prosthesis repair of abdominal aortic aneurysms is based upon the development of low-profile devices that can be expediently deployed within the aneurysm, excluding it from intraluminal pressure. Many factors affect the treatment of patients in this manner, including the morphology of the proximal and distal fixation sites, the diameter and disease state of the access vessels, and the ability of the device to conform to the many anatomic variations of aneurysms. In addition, preliminary data suggest there is progressive shrinkage and morphologic change in the configuration of an aneurysm following exclusion, which not only affects the alignment of the device but may also influence its healing and stability. This paper reviews the morphologic parameters of aneurysms relevant to endovascular repair and describes the imaging technologies used to assess these parameters before, during, and after intervention.

Utility of intravascular ultrasound in peripheral interventions.

Endovascular imaging techniques encompass a variety of methods, including angiography, computed tomography, magnetic resonance imaging, angioscopy, and intravascular ultrasound. Each method provides unique information regarding the continuity of vascular structures and the morphology and distribution of lesions. Although arteriography has been the "gold standard" for imaging arterial anatomy, recent data have confirmed that even sophisticated arteriographic imaging substantially underestimates the degree of residual lesions, and that future observations and end-points for treatment will most likely be determined by data accumulated by computed tomography, magnetic resonance imaging, angioscopy, and intravascular ultrasound. Successful therapeutic applications of endovascular devices have developed because of improved patient selection using computed tomography, spiral computed tomography, magnetic resonance imaging, and computerized high-resolution angiography. Procedural success has been enhanced by improved mobile cinefluoroscopy, angioscopy, intraluminal ultrasound monitoring of angioplasty procedures, and the use of intravascular ultrasound for stent and stent-graft sizing and deployment. Newly developed methods and low-profile delivery systems enabling deployment and fixation of vascular prostheses by an endoluminal approach have heightened the interest of many interventionalists, particularly surgeons, in the use of endovascular surgical techniques. The evolution of this method promises to add a new dimension to the treatment of vascular lesions and relies heavily on the incorporation of miniaturized imaging systems, such as intravascular ultrasound, as a means to provide precise placement of devices.

Neurochemical alterations in asymptomatic abstinent cocaine users: a proton magnetic resonance spectroscopy study.

Cocaine can cause a variety of neuropsychiatric and neurobehavioral complications; however, it is uncertain whether cocaine causes persistent cerebral structural and neurochemical abnormalities in asymptomatic users. We studied 52 African-American men (26 human immunodeficiency virus-negative asymptomatic heavy cocaine users and 26 normal subjects). Ventricle-to-brain ratio (VBR) and white matter lesions (WML) were quantified on magnetic resonance imaging. N-acetyl-containing compounds (NA), total creatine, choline-containing compounds, myo-inositol, and glutamate + glutamine were measured with in vivo proton magnetic resonance spectroscopy, VBR and WML were not significantly different in the cocaine users compared to the normal controls. Elevated creatine (+7%; p = .05) and myo-inositol (+18%; p = .01) in the white matter were associated with cocaine use. NA, primarily a measure of N-acetyl aspartate and neuronal content, was normal. Normal NA suggest no neuronal loss or damage in the brain regions examined in these cocaine users. Therefore, we conclude that neurochemical abnormalities observed might result from alterations in nonneuronal brain tissue.

Cognition and white matter hyperintensities in older depressed patients.

OBJECTIVE: The authors compared amounts of white matter hyperintensity in late- and early-onset depressed patients and never-depressed older subjects, compared neuropsychological function in these groups, and investigated the association between white matter hyperintensities and cognitive function in depression. METHOD: Sixty currently depressed patients whose first depression occurred after age 50 years, 35 depressed patients over age 50 whose first depression occurred before age 35, and 165 nonpsychiatrically ill subjects over age 50 underwent magnetic resonance imaging (MRI) and neuropsychological evaluation. Areas of white matter hyperintensity were measured from MRI images. RESULTS: The late-onset patients had more white matter hyperintensity than either of the other groups. Compared to the nondepressed subjects, the patients had significantly lower scores in the cognitive domains of nonverbal intelligence, nonverbal memory, constructional ability, executive ability, and information processing speed. The cognitive abnormalities were mostly confined to the late-onset patients, and the presence of a large amount of white matter hyperintensity was associated with significantly poorer executive skills. However, most of the scores were not in the significantly impaired range. CONCLUSIONS: Large amounts of white matter hyperintensity are more frequent in patients with late-onsetdepression than in elderly subjects with early-onset or no depression. Both late- and early-onset elderly depressed patients show mild decrements in some "right hemisphere" cognitive skills; the late-onset subjects also show deterioration in information processing speed and executive functions. Patients with large amounts of white matter hyperintensity have significantly poorer executive function.

Preliminary clinical outcome and imaging criterion for endovascular prosthesis development in high-risk patients who have aortoiliac and traumatic arterial lesions.

PURPOSE: This report reviews our preliminary experience of prospective treatment of arterial lesions with endoluminal grafts in a Food and Drug Administration (FDA)-approved, investigator-sponsored Investigation Device Exemptions study. The utility and accuracy of various imaging methods, including angiography, cinefluoroscopy, computed tomography (CT), intravascular ultrasonography (IVUS), and duplex scanning, in performing the procedures was also assessed. METHODS: Thirty-one patients were evaluated; 17 patients were treated, including 11 with abdominal aortic aneurysms, one with an aortic occlusive lesion, two with iliac artery aneurysms, and three with traumatic arteriovenous fistulas. Twelve of the 14 patients who had aorta and iliac artery lesions were high-risk. The mean follow-up of patients treated was 9 months (range, 6 to 15 months). RESULTS: Aortoaortic endoluminal interposition procedures were not successful for treating abdominal aortic aneurysms early in the study (n = 3). Aortoiliac endoluminal bypass, contralateral iliac artery occlusion, and femorofemoral bypass procedures were successful in seven of eight subsequent cases (88%), with no incidence of endoleaks at either the proximal or distal fixation sites using the deployment methods described in this report. The 30-day operative mortality rate on follow-up evaluations for patients who underwent aortoiliac procedures was 14% (two of 14). Other major complications included transient renal failure in three patients that required short-term (two to eight times) dialysis, one arterial perforation and one dissection, and one prolonged intubation. No myocardial infarctions or strokes occurred. After major complications or identification of limitations in the study, the protocol was modified with the approval of the FDA to help avoid the recurrence of the same problems. There were no deaths or complications in the trauma cases. CONCLUSIONS: Contrast-enhanced CT (axial images and spiral reconstructions) was the most accurate method to determine candidacy for aortoiliac procedures and to choose the site for deployment of the devices. Angiographic scans were misleading in several patients regarding the critical determinants of patient candidacy and device deployment, particularly regarding the presence of a distal aortic neck. Cinefluoroscopy was used in all patient and was particularly useful for determining the continuity of vascular structures and the anatomy of branch arteries and for enabling precise positioning of stent devices. Determination of fixation sites and assessing dimensional information by cinefluoroscopy and angiography were limited by inaccuracies produced by image magnification, parallax, and uniplanar views. IVUS was used to determine the morphologic features of vascular structures (i.e., calcium, thrombus), to perform real-time observation of the expansion of devices, and to assure firm fixation of balloon-expanded stents before the procedures were completed. Duplex scanning was very helpful in assessing and identifying precisely the location of arteriovenous fistulas before intervention and provided assessment at follow-up intervals. Three-dimensional reconstruction imaging technologies such as spiral CT were particularly helpful for assessing the morphologic features of vascular anatomy before the intervention and at follow-up intervals, whereas 3-D IVUS provided a similar real-time perspective during the procedure.

Neuroimaging findings in patients with AIDS.

An increasing number of patients are presenting with central nervous system complications of human immunodeficiency virus infection. New imaging technologies such as magnetic resonance imaging, magnetic resonance proton spectroscopy, single-photon emission computed tomography, and positron emission tomography are playing an ever-increasing role in the diagnosis of these complications. As therapeutic modes improve, imaging may assume a growing role in monitoring the responses to therapy among these patients.

Brain imaging, antidepressants, and ethnicity: preliminary observations.

Magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) using 99mTc-hexamethylpropylene amine oxime (HMPAO) evaluations were completed on African-American and Caucasian depressed patients prior to their participation in an antidepressant medication trial. The degree of white matter hyperintensities (WMH), ventricle-to-brain ratio (VBR), and uptake of HMPAO did not vary significantly between the groups. After 1 week of placebo run-in, patients received paroxetine in an 8-week, open-label, flexible-dose trial. Final dosages and side effects were similar between groups. There was a trend for the Caucasian patients to have a better treatment response, but the relatively small sample size makes this finding tentative. In general, there were no major differences in either baseline neuroimaging findings or response to paroxetine between these two ethnic groups.

Fulminant cerebral lymphoma in AIDS.

Three cases of cerebral lymphoma in patients with acquired immunodeficiency syndrome is presented. They are remarkable for their extremely rapid progression, which simulated an infectious processes during trials of antitoxoplasma therapy. Fourteen days of therapy are generally required to assess a negative response. However, earlier biopsies and shorter therapeutic trials may be indicated in these patients.

Aneurysmal bone cyst of the thoracic spine: evolution after particulate embolization.

A case of aneurysmal bone cyst of the thoracic spine treated with serial particulate embolization responded with involution of soft-tissue and cystic components and diffuse ossification of the mass. Reappearance of foci of bony rarefaction or cystic change at 4-year follow-up indicates the need for continued surveillance.

Reduction of cerebral blood flow in older depressed patients.

BACKGROUND: We investigated regional cerebral blood flow in older, drug-free depressed patients and examined factors that might be related to rCBF. METHODS: We studied 39 physically healthy depressed patients over the age of 50 years and 20 psychiatrically healthy control subjects. Regional cerebral blood flow was measured with single photon emission computed tomography, using both xenon 133 (to quantify regional cerebral blood flow) and 99mTc-hexamethylpropylene amine oxime (to make regional comparisons). From magnetic resonance imaging, we derived a semiquantitative measure of areas of white matter hyperintensity and a ventricle-to-brain ratio. RESULTS: Patients exhibited a global reduction in regional cerebral blood flow compared with controls, with the orbital frontal and inferior temporal areas affected bilaterally. Regional cerebral blood flow was also reduced in higher brain slices in the right but not the left hemisphere. Significant predictors of lowered regional cerebral blood flow were being depressed, being male, and having a greater ventricle-to-brain ratio. There appeared to be a subgroup of patients who demonstrated large areas of white matter hyperintensity and low regional cerebral blood flow. CONCLUSIONS: Cerebral blood flow was lower in older, medication-free depressed patients than in age-matched control subjects, involved the orbital frontal and anterior temporal regions, and was more reduced in the right hemisphere.

Cerebral abnormalities in myotonic dystrophy. Cerebral blood flow, magnetic resonance imaging, and neuropsychological tests.

OBJECTIVE: To study cerebral abnormalities in myotonic dystrophy (MD) and determine the different patterns of cerebral function in patients with MD with maternal (mMD) vs paternal (pMD) inheritance. DESIGN: Patients with MD and normal controls were studied with neuropsychological testing, magnetic resonance imaging, and single photon emission computed tomography. SETTING: Studies were done at Harbor-UCLA Medical Center, Torrance, Calif. PATIENTS AND OTHER PARTICIPANTS: Twenty-two consecutive-patients with MD, 11 of whom had pMD and eight mMD, and 10 normal controls were studied. Diagnoses were made on the basis of family history, electromyography, and clinical examinations. Normal subjects in the same age distribution were studied for comparisons. RESULTS: We found significantly lower neuropsychological performance and cerebral blood flow in the patients with MD compared with the controls. Patients with mMD had statistically lower scores on IQ tests and more extensive cerebral hypoperfusion when compared with those with pMD. Changes in cerebral blood flow were most severe in the frontal and temporoparietal association cortex. Cerebral blood blow measures strongly correlated with IQ. CONCLUSIONS: Patients with mMD had earlier onset of disease and lower IQs than the pMD group. The pattern of cerebral perfusion in the mMD group was consistent with a diffuse brain injury, while cerebral perfusion in pMD showed more minor changes. These findings emphasize the cognitive differences between mMD and pMD.

Transarterial embolization of vertebral hemangioma.

PURPOSE: The authors retrospectively reviewed their 4-year clinical experience to determine the role of transarterial embolization in the treatment of symptomatic vertebral hemangioma. PATIENTS AND METHODS: Eight patients (age range, 12-56 years) underwent a total of 10 embolization procedures; one patient underwent three procedures. The lesions were located between T-5 and L-5, and all patients presented with pain and symptoms referable to the lower extremities. RESULTS: Embolization was technically successful in all patients, and no complications were encountered. Six of eight patients underwent surgery within 48 hours of embolization; four of the six showed significant clinical improvement immediately after surgery and on follow-up (average, 34 months). Two patients did not improve postoperatively. Two patients initially underwent embolization as the sole therapy. The first refused surgery and did not improve clinically; the second underwent two embolization procedures without clinical improvement and eventually underwent a third followed by surgery, which resulted in clinical improvement. All patients were hemodynamically stable during surgery, and blood loss was not problematic in any patient. CONCLUSIONS: Overall, surgery was an effective treatment for symptomatic vertebral hemangioma and the authors conclude that transarterial embolization of vertebral hemangioma is a safe and efficacious adjunctive procedure to such surgery. However, embolization was not as promising as a sole therapeutic modality in this small group of patients.

Adult cerebellar medulloblastoma: imaging features with emphasis on MR findings.

PURPOSE: To describe the MR imaging features of cerebellar medulloblastoma in the adult. MATERIALS AND METHODS: The neuroimages and records of 15 adults with proved cerebellar medulloblastoma were retrospectively evaluated. In 12 patients, preoperative MR scans were reviewed; nine had Gd-DTPA-enhanced scans. RESULTS: Of the 12 tumors evaluated preoperatively, eight were hemispheric, two hemispheric-vermian, and two vermian. Tumor margins were well demarcated, except in three cases, two of which had large infiltrative tumors. In 10 cases, tumor extended to the brain surface, and in five of these, contiguity with the tentorium or cerebellopontine angle cistern was such than an extraaxial tumor was considered. The tumors were typically hypointense on T1 but a spectrum was seen on T2-weighted images. Enhancement ranged from minimal and patchy to marked. One tumor became isointense after Gd-DTPA. Other features included cystic changes, hemorrhage, exophytic invasion at the cerebellopontine angle, spinal cerebrospinal fluid seeding, intraventricular seeding, and bone metastasis. CONCLUSION: Although there is no pathognomonic MR appearance of adult cerebellar medulloblastoma, the finding of a well-demarcated, mild to moderately enhancing hemispheric mass involving the brain surface in a young adult is suggestive of medulloblastoma. Awareness that this tumor may resemble meningioma may avoid misdiagnosis and aid surgical planning.

Peripheral angiography: optimal technique and current status in vascular imaging.

Angiography is the standard with which new methods of vascular imaging are compared. In this article, selected recent developments affecting the practice of angiography will be discussed. First, a brief review and update of contrast media for intravascular use will be presented. Second, principles and current methods of optimizing the diagnostic arteriogram will be covered with emphasis on the extremities and aorto-femoral angiography. Finally, some of the advantages, limitations, and the role of modern angiography will be discussed.