Increasing Access to Care for Transgender/Gender Diverse Youth Using Telehealth: A Quality Improvement Project

Purpose: We sought to expand telehealth at an academic multidisciplinary pediatric gender center to increase access to gender-affirming care without compromising communication, privacy, or patient satisfaction. Materials and Methods: Patient needs assessments were performed from January 2019 to March 2020. The severe acute respiratory syndrome coronavirus 2 pandemic accelerated implementation of the quality improvement project, and clinically appropriate patients were scheduled for video visits starting March 16, 2020. From September 8, 2020 to October 2, 2020, caregivers of transgender and gender diverse (TGD) minors or TGD young adults pursuing gender-affirming medications completed 9-item surveys evaluating communication quality and privacy, access to care, and quality of services for video and clinic visits. Answers were rated via Likert scales (1 = strongly agree, 5 = strongly disagree; 1 = less travel time, 4 = more travel time). Results: Needs assessment (n = 69) showed that 63.8% felt that video visits would improve follow-up. Survey participants (n = 91) reported statistically significant differences (p < 0.05) in several areas. Compared with clinic visits, video visits were more convenient, 1.21 ± 0.435 versus 2.36 ± 1.207, took less time from other activities, 4.55 ± 0.522 versus 2.93 ± 1.281, required less travel time, 1.03 ± 0.180 versus 2.63 ± 0.901, and were more acceptable, 1.35 ± 0.545 versus 1.65 ± 0.736. Participants were more likely to choose video visits in the future, 1.32 ± 0.555 versus 1.57 ± 0.732. There were no statistically significant differences in communication quality, privacy, or overall satisfaction. Conclusion: An integrated clinic-video visit model increases access to gender-affirming care for TGD youth while maintaining excellent communication, privacy, and patient satisfaction.

Religiosity and veteran mental health compared with non-veterans

BACKGROUND

While the potential buffering effects of spirituality are well established in the general population, how spirituality affects those in extremely high-stress occupations like the military and law enforcement is less clear.

AIMS

This paper explores the possibility that spiritual influences may operate differently among military veterans than other people. It specifically proposes that attendance at religious services is an especially important buffer for combat veterans.

METHODS

This study engaged in a secondary analysis of 74 480 respondents from the National Survey on Drug Use and Health for the years 2013-17. The respondents were split into four groups; veterans with combat experience before September 2001, veterans with combat experience since September 2001, veterans with no combat experience and non-veterans.

RESULTS

The likelihood of mental illness decreased in the general population along three different measures of religion; the importance of religion, friendships that shared religious beliefs and attendance at religious services. The relationship was weak and disappeared when controls for non-religion variables were included. A major exception was combat veterans, for whom the religious effects were limited to attendance at services, and the effect survived with the addition of non-religion control variables.

CONCLUSIONS

Mental health professionals, chaplains, pastoral counsellors and clergy need to recognize that among the therapeutic benefits of religious attendance and recognize the value of the religious rituals as ends in themselves.

Clinical Study of Fetal Mesencephalic Intracerebral Transplants for the Treatment of Parkinson's Disease

This study reports our findings from 22 patients (ages ranging from 42 to 73 yr; mean = 55.2) with recalcitrant idiopathic Parkinson's disease (PD) who received implants of fetal ventral mesencephalic tissue using an MRI-guided stereotactic procedure and who have been followed for at least 6 mo postoperatively, employing the guidelines established by the Core Assessment Program for Intracerebral Transplantations. Evaluations were videotaped and were performed both on and off levodopa medications. To date, we have seven patients with 24 mo, three with 18 mo, three with 12 mo, and nine with 6 mo of postsurgical assessments. Comparing surgical outcomes to levels prior to fetal transplants we found: 1) mean levodopa levels were reduced 46% at 6 mo, 12% at 12 mo, 20% at 18 mo, and 54% at 24 mo; 2) Unified Parkinson's Disease Rating Scale (UPDRS) scores with patients on levodopa were improved by an average of 38% (6 mo), 50.2% (12 mo), 69.3% (18 mo), and 73.9% (24 mo), while off medication scores showed reductions ranging from 24.7% at 6 mo to 55.1% at 24 mo. Other measures, including Hoehn-Yahr staging, Activities of Daily Living, and dyskinesia rating scales, were also significantly improved following fetal transplants. Timed motor tasks (finger dexterity, supination-pronation, foot tapping, and Stand-Walk-Sit) performance also demonstrated highly significant improvements. Patient's self-rating scores indicated that the patients typically perceived substantial improvements in their condition. However, substantial variability in the improvements following surgery still persists and range from nominal improvements in performance to significant changes that can be classified as altering the overall lifestyle of the patients. To date, 4 of the 22 subjects were considered by the physicians to be nonresponders; that is, there were no clinically relevant improvements in these patients' conditions.

A randomized study to decrease the use of potentially inappropriate medications among community-dwelling older adults in a southeastern managed care organization

BACKGROUND

Despite progress in describing the problem of potentially inappropriate medication (PIM) use, there have been few prospective studies demonstrating that interventions with specific medication criteria can make a difference in decreasing the use of problematic drugs in older adults.

OBJECTIVE

To design an intervention study to change physician behavior regarding PIM prescribing to older patients.

STUDY DESIGN AND METHODS

A prospective randomized block design was used during an 18-month period from January 2001 to June 2002. The study population was primary care physicians (n = 355) in the Medicare + Choice product line of a southeastern managed care organization and their patients 65 years and older. There were 170 physicians in the treatment group and 185 in the control group. Physicians were assigned to the treatment or usual-care, groups using a randomization table, and each group included physicians who had and had not prescribed a PIM.

RESULTS

Approximately 71% (84/118) of the physicians in the intervention group who prescribed a PIM completed and faxed back at least 1 potentially inappropriate medication form to the managed care organization. On 15.4% (260/1692) of the medication forms, physicians made some change regarding PIM use.

CONCLUSIONS

Although many studies have addressed medication use among older adults, intervention studies aimed at influencing physician prescribing in this population are limited. This study describes a low-cost, replicable method to contact and educate physicians on drug therapy issues in older adults.

Studies of the vicarious traumatization of college students by the September 11th attacks: effects of proximity, exposure and connectedness

From mid-October 2001 through the end of November 2001, we collected fairly large sets of questionnaires from undergraduates at three public universities (Albany, NY, n = 507, Augusta, GA, n = 336, Fargo, ND, n = 526 ) to assess rate of acute stress disorder (ASD) and level of ASD symptoms following the September 11th attacks, rate of current posttraumatic stress disorder (PTSD) and level of PTSD symptoms, and current level of depressive symptoms resulting from the September 11th attacks. We also gathered information on exposure to media coverage of the attacks, connectedness to the World Trade Center (WTC) and personnel there, and degree of engagement in reparative acts such as giving blood, attending vigils. We found higher levels of ASD, ASD symptoms, PTSD and PTSD symptoms as a function of geographical proximity to New York City (and within the Albany site, proximity of students' homes) and gender. Exposure (hours of TV watched) was a predictor in some instances as was connectedness to WTC victims. ASD symptoms were the strongest predictor of subsequent PTSD symptoms. Path models accounted for over 60% of the variance in PTSD symptoms.

Medical students' readiness to provide lifestyle counseling for overweight patients

In order to assess medical students' readiness to engage in lifestyle counseling regarding nutrition, physical activity, and other health behaviors, the authors examined the knowledge, attitudes, and health behaviors of medical students. The authors analyzed questionnaire responses of 290 medical students in their first, second, or third year. Students were generally knowledgeable about cardiovascular disease risk factors, however they were less knowledgeable about body mass index (BMI) and specific nutrition and physical activity recommendations. Students were confident in the ability of physicians to change patients' health behaviors and had positive attitudes about providing lifestyle counseling. The upper-level students held significantly less positive attitudes than the first-year students. Almost half the sample reported regularly making unhealthy dietary choices. Only 23% of the sample met the public health guidelines for accumulating 30 min of moderate activity on at least 5 days a week. Third-year students engaged in significantly less activity than their underclassmen. Although medical students express positive attitudes toward providing lifestyle counseling, they require more instruction in the areas of weight screening, nutrition, and physical activity recommendations in order to be helpful to their patients. Because physicians who practice health behaviors are more likely to provide counseling, it would be beneficial to integrate an emphasis on student health into medical curricula.

Optimization of an exogenous metabolic activation system for FETAX. I. Post-isolation rat liver microsome mixtures

The developmental toxicity of cyclophosphamide, coumarin, 2-acetyl-aminofluorine (2-AAF), and trichloroethylene (TCE) was assessed with Frog Embryo Teratogenesis Assay: Xenopus (FETAX). Late Xenopus laevis blastulae were exposed to each test material for 96-h in two separate static-renewal tests with and without the presence of five differently induced exogenous metabolic activation systems (MAS). The MAS consisted of Aroclor 1254- (Aroclor 1254 MAS), isoniazid- (INH MAS), phenobarbital- (PB MAS), or beta-naphthoflavone- (beta-NF MAS), or a post-isolation mixture (mixed MAS) of INH-, PB-, and beta-NF-induced rat liver microsomes. Addition of the Aroclor 1254 MAS bioactivated cyclophosphamide, coumarin, 2-AAF, but not TCE. Addition of the PB MAS bioactivated cyclophosphamide, weakly bioactivated coumarin and 2-AAF, but had no effect on TCE developmental toxicity. The beta-NF MAS bioactivated coumarin and 2-AAF, weakly bioactivated cyclophosphamide, but did not alter the developmental toxicity of TCE. Addition of the INH-induced MAS only bioactivated TCE, whereas the post-isolation mixed MAS bioactivated each test material. Based on LC50 and EC50 (malformation) values, embryo growth, and types and severity of induced malformations, each test material was developmentally toxic. Use of post-microsome isolation mixtures from differentially induced rat livers increased the efficacy of the exogenous MAS routinely used by FETAX.

Optimization of an exogenous metabolic activation system for FETAX. II. Preliminary evaluation

The developmental toxicities of five test compounds including carbon tetrachloride, urethane, phenacetin, parathion, and chloroform, were evaluated using Frog Embryo Teratogenesis Assay--Xenopus (FETAX), with minor modification. Post-isolation mixtures of differently-induced rat liver microsomes (phenobarbital- (PB), beta-naphthoflavone- (beta-NF), and isoniazid- (INH)-induced preparations) were co-cultured directly with X. laevis embryos. Results from these studies suggest that the Aroclor 1254-induced MAS could effectively be replaced by a mixed lot of PB-, beta-NF-, and INH-induced rat liver microsomes. Each of the test materials were found to be developmentally toxic when bioactivated by the mixed MAS.

Effects of pond water, sediment and sediment extract samples from New Hampshire, USA on early Xenopus development and metamorphosis: comparison to native species

In an effort to assess potential ecological hazards to amphibian species in selected regions within New Hampshire, the traditional Frog Embryo Teratogenesis Assay-Xenopus (FETAX), a 14-/21 day tail resorption thyroid disruption assay and >30 day limb development tests were conducted with representative surface water and sediment samples. Two separate sets of samples collected from five sites were evaluated. The primary objectives of the study were to determine if samples were capable of inducing early embryo-larval maldevelopment, to determine if maldevelopment included limb defects, to determine if thyroxine co-administration altered the rates of limb malformation and to evaluate the impact of the samples on growth rates, developmental progress and metamorphic climax. Results from these studies suggested that pond water and sediment extract samples, but not whole sediment samples, from B2, FW, LP and W ponds were capable of inducing abnormal early embryo-larval development. In addition, water samples from B2 and W ponds induced significant abnormal hindlimb development. Some abnormal forelimb development was noted in the tail resorption studies, but not to the same extent as the hindlimbs. Each of the water samples induced appreciable developmental delay, including the paired reference site B1, which could be reversed by the addition of exogenous thyroxine.

Chronic boron or copper deficiency induces limb teratogenesis in Xenopus

Sets of adult male and female Xenopus laevis were administered a boron-deficient (-B) diet under low-boron culture conditions, a boron-supplemented (+B) diet under ambient boron culture conditions, a copper-deficient (-Cu) diet under low-copper culture conditions, or a copper-supplemented (+Cu) diet under ambient copper culture conditions, for 120 d. Adults from each group were' subsequently bred, and the progeny were cultured and bred. Results from these studies indicated that although pronounced effects on adult reproduction and early embryo-larval development were noted in the -B F1 generation, no effects on limb development were observed. No significant effects on reproduction, early embryogenesis, or limb development were noted in the +B group, irrespective of generation. Highly specific forelimb and hindlimb defects, including axial flexures resulting in crossed limbs and reduction deficits, were observed in -B F2 larvae, but not in the +B F2 larvae. As was noted in the boron-deficiency studies, significant effects on reproduction and early embryo development were observed in the -Cu F1 generation, but not in the +Cu F, generation. Unlike the effects associated with boron deficiency, maldevelopment of the hindlimbs (32 responders, n = 40) was found in the F1 generation.

Preliminary validation of a short-term morphological assay to evaluate adverse effects on amphibian metamorphosis and thyroid function using Xenopus laevis

Short-term static-renewal studies were performed on Xenopus laevis embryos with 16 selected test materials from day 50 (stage 60) to day 64 (stage 66) (14-day test) to evaluate effects on tail resorption and thyroid function. Of the 16 test materials, nine were found to inhibit significantly the rate of tail resorption, four were found to stimulate metamorphosis and three had no appreciable effect on the rate of metamorphosis. In an effort to determine if the morphological effects observed were related to alteration in thyroid activity, measurement of triiodothyronine (T3) in the test organisms and coadministration studies using thyroxine (agonist) or propylthiouracil (antagonist) were performed based on the morphological response noted during tail resorption. Of the nine compounds found to inhibit the rate of tail resorption, six were found to reduce the levels of T3. In each case, the inhibitory response could be at least partially alleviated by the co-administration of thyroxine. Larvae exposed to the four stimulatory agents had somewhat elevated levels of T3 and were responsive to propylthiouracil antagonism. These results suggest that 12 of the 14 compounds tested in this study that altered the rate of tail resorption did so via the thyroid axis. Overall, the X. laevis model appeared to be a suitable system for evaluating the impact of environmental agents and chemical products on thyroid function.

Transfusion management of an IgA deficient patient with anti-IgA and incidental correction of IgA deficiency after allogeneic bone marrow transplantation

A patient with multiple myeloma was noted to have an IgA deficiency during investigation of a possible transfusion reaction due to IgA deficiency and anti-IgA. Because of the patient's age, otherwise good health, and early stage of disease, he was enrolled in a research treatment protocol that involved an allogeneic bone marrow transplant (BMT). The BMT successfully put the patient in complete remission from his multiple myeloma and corrected his IgA deficiency. Class-specific IgG anti-IgA antibody that had been identified prior to BMT was no longer detectable in his plasma. Anaphylactic transfusion reactions were successfully avoided by using a combination of IgA-deficient and washed blood components including the marrow graft, and IgA-reduced intravenous immunoglobulin.

Social physique anxiety and disordered eating: what's the connection?

Social physique anxiety (SPA) is highly correlated with other body image measures that have been considered to be important in understanding eating disorders. However, SPA has not been directly studied with respect to eating disorders. Thus, the purpose of this investigation was to examine the link between SPA and measures of eating disorder symptomatology to determine if SPA should be considered as an additional risk factor in the prediction of eating disturbances. One hundred and sixty female undergraduates completed questionnaires measuring body mass index (BMI), social physique anxiety (SPAS), anorexic symptoms (EAT), bulimic symptoms (BULIT-R), depression (CES-D), self-esteem (SES) and obligatory exercise (OEQ). Regression analyses revealed that SPA and depression were the psychological correlates that predicted bulimic symptomatology and that SPA, depression, and obligatory exercise predicted anorexic symptomatology; all variables were positively related to eating disorder symptoms. Overall, the results indicate that social physique anxiety appears to be a useful construct for understanding eating disorder symptoms in female undergraduates.

Outcome following intrastriatal fetal mesencephalic grafts for Parkinson's patients is directly related to the volume of grafted tissue

The effect of varying the volume of grafted fetal mesencephalic tissue was studied in patients with idiopathic Parkinson's disease in a single-blinded study. Evaluations were performed according to the Core Assessment Program for Intracerebral Transplantation and videotaped both prior to transplantation and in 3-month intervals after transplantation. One group, low-volume grafts (six subjects; mean age, 57.2 years), received ventral mesencephalon grafts from one to two donors with an approximate volume up to 20 mm3, while the second group, high-volume grafts (seven subjects; mean age, 59.5 years), received ventral mesencephalon grafts from three or more donors with an approximate volume of 24 mm3. Both groups of patients demonstrated significant improvement over presurgical baseline scores on all major parameters. The high-volume group had significantly greater improvements on all the UPDRS scores and also better performance on a variety of motor performance tasks over that seen among low-volume patients. These results indicate that variations of fetal graft volume do have an impact on clinical outcome.

Magnetoencephalographic evidence for common sources of long latency fields to rare target and rare novel visual stimuli

This study used magnetoencephalography to examine the possibility that different generators account for the long-latency event-related potential (P300), evoked by rare target and by rare non-target, novel visual stimuli, in a visual oddball counting task performed by seven subjects. As expected, P300 peak latency was longer in response to rare targets compared to novel, non-target stimuli. Two main source regions were found for the Target- as well as for the Novel-P300, one in the temporal and one in the occipital lobe. Centers of neural activity were observed in the vicinity of the superior temporal sulcus, in the hippocampal formation and parahippocampal gyrus and in the occipital extrastriate cortex. It appears that the brain structures which contributed to the generation of the P300 response to both the target and the novel visual stimuli overlapped to a great extent.

Clinical study of fetal mesencephalic intracerebral transplants for the treatment of Parkinson's disease

This study reports our findings from 22 patients (ages ranging from 42 to 73 yr; mean = 55.2) with recalcitrant idiopathic Parkinson's disease (PD) who received implants of fetal ventral mesencephalic tissue using an MRI-guided stereotactic procedure and who have been followed for at least 6 mo postoperatively, employing the guidelines established by the Core Assessment Program for Intracerebral Transplantations. Evaluations were videotaped and were performed both on and off levodopa medications. To date, we have seven patients with 24 mo, three with 18 mo, three with 12 mo, and nine with 6 mo post-surgical assessments. Comparing surgical outcomes to levels prior to fetal transplants we found: 1) mean levodopa levels were reduced 46% at 6 mo, 12% at 12 mo, 20% at 18 mo, and 54% at 24 mo; 2) Unified Parkinson's Disease Rating Scale (UPDRS) scores with patients on levodopa were improved by an average of 38% (6 mo), 50.2% (12 mo), 69.3% (18 mo), and 73.9% (24 mo), while off medication scores showed reductions ranging from 24.7% at 6 mo to 55.1% at 24 mo. Other measures, including Hoehn-Yahr staging, Activities of Daily Living, and dyskinesia rating scales, were also significantly improved following fetal transplants. Timed motor tasks (finger dexterity, supination-pronation, foot tapping, and Stand-Walk-Sit) performance also demonstrated highly significant improvements. Patient's self-rating scores indicated that the patients typically perceived substantial improvements in their condition. However, substantial variability in the improvements following surgery still persists and range from nominal improvements in performance to significant changes that can be classified as altering the overall lifestyle of the patients. To date, 4 of the 22 subjects were considered by the physicians to be nonresponders; that is, there were no clinically relevant improvements in these patients' conditions.

Multiple source localization using genetic algorithms

We present a new procedure for localizing simultaneously active multiple brain sources that overlap in both space and time on EEG recordings. The source localization technique was based on a spatio-temporal model and a genetic algorithm search routine. The method was successfully applied to the localization of two dipole sources from several sets of simulated potentials with various signal-to-noise ratios (SNR). The different SNR values resembled evoked responses and epileptic spikes as commonly seen in the laboratory. Results of the simulation studies yielded localization accuracy ranging from 0.01 to 0.07 cm with an SNR of 10; from 0.02 to 0.26 cm with an SNR of 5; and from 0.06 to 0.73 cm when the SNR was equal to 2. Additionally, two sets of simulations were based on the dipole arrangements and time activities of data obtained during electrical stimulation of the median nerve in human subjects. These studies yielded localization accuracy within 0.1 cm. We also studied the localization accuracy of the algorithm using a physical model incorporating potential measurements of two current dipoles embedded in a sphere. In this situation the algorithm was successful in localizing the two simultaneously active sources to within 0.07-0.15 cm.

MEG and ECoG localization accuracy test

We tested the localization accuracy of magnetoencephalography (MEG) and electrocorticography (ECoG) for a current dipole in a saline filled sphere at depths ranging from 1 to 6 cm at 1 cm intervals. We used standard neuromagnetometer placements and subdural electrode grids, previously employed for patient studies, with precise measurements of sensor and electrode locations with a 3-dimensional spatial digitizer. MEG and ECoG had comparable accuracy with mean errors of 1.5 and 1.8 mm, respectively. It appears that use of the spatial digitizer increases accuracy for both MEG and EGoG localizations. The larger errors in the ECoG with increasing depths could be attributed to under-sampling of the spatial pattern of the field which spreads out with deeper sources. It should be noted that in clinical applications a grid of the dimensions used here would most typically be used for superficial sources on the cortex with depth recordings being preferred for investigations of deep epileptogenic activity. Results are encouraging for continued development of non-invasive MEG methods for further definition of epileptogenic zones in the brain.

Efficacy and safety of plateletpheresis by donors with low-normal platelet counts

Our practice is to defer donors with blood platelet (PLT) counts of < 180 x 10(9)/L because PLT yields are low, when compared to PLT units collected from donors with higher counts. In an attempt to minimize deferral, we determined whether 33 donors, who repeatedly demonstrated low-normal PLT counts (150-180 x 10(9)/L) on multiple occasions during the prestudy period. might safely donate satisfactory apheresis PLT units simply by extending the apheresis collection time by 20 min (men) and 40 min (women). Repeat plateletpheresis procedures were scheduled at > or = 28-day intervals. The mean PLT yield (N = 92) was 5.8 x 10(11) with 97% of units containing > or = 4.0 x 10(11) PLTs. Although donors entered the study only after they had repeatedly exhibited predonation PLT counts of < 180 x 10(9)/L, PLT counts were not always below this level at the time of study collections. However, analyzing only donations with true predonation PLT counts of < 180 x 10(9)/L (N = 35), the mean PLT yield was excellent-5.4 x 10(11) with 97% of units containing > or = 4.0 x 10(11) PLTs. The average fall in donor blood PLT counts (pre-vs. postdonation) was 36%, with only ten of 99 postdonation counts being < 100 x 10(9)/L; the lowest was 69 x 10(9)/L. Thus, extending the apheresis collection time permitted donors who in the past were routinely deferred because of low PLT counts to safely donate satisfactory PLT units.

Comparisons of MEG, EEG, and ECoG source localization in neocortical partial epilepsy in humans

In order to delineate the characteristics of epileptic spikes, 1946 different spikes were studied in 6 patients with complex partial epilepsy. Non-invasive MEG and EEG source analysis of interictal spikes were contrasted to ECoG localization, surgical outcome and presence of lesions on MRI. Results indicated that: (1) using the most frequent occurring spike topography patterns from a large sample of spikes improved goodness-of-fit values for both MEG and EEG localization, (2) when spike patterns could be appropriately matched on several successive MEG measurements to provide an adequate matrix (3 of 6 subjects), there was excellent agreement between MEG dipole sources and ECoG sources as well as surgical outcome and presence of MRI lesions, (3) EEG source analyses also gave good results but not as consistently as MEG.

Somatosensory evoked fields and potentials following tibial nerve stimulation

We studied evoked magnetic fields and electrical potentials following stimulation of the tibial nerve in a group of 24 normal subjects. Both magnetic and electrical recordings demonstrated a series of oscillatory patterns consisting of four peaks (two positive and two negative) occurring between 40 and 100 msec. Magnetic field source localization of all four peaks using a dipole-in-a-sphere model indicated that all four peaks emanated from the same cortical surface located within the longitudinal fissure, an area typically associated with somatosensory function.

Slow magnetic flux from human frontal cortex

Slow magnetic fields concurrent with two successive contingent negative variations (CNVs) were elicited in 8 subjects during visual recognition tasks involving pattern versus place discrimination. All stimuli were presented as a rectangular array of lights with various patterns of 6 lights at the center and, simultaneously, with places indicated by missing lights at the periphery. One of two possible stimuli (warning) started each trial, indicating whether pattern or place recognition should be performed on the following two stimuli. The purposes of the experiment were to localize the sources of the slow magnetic fields equivalent to the CNVs and to address the issue of regional specialization of prefrontal cortical function. Results indicated that the equivalent current dipoles (ECDs) found as solutions for the measured slow fields were indeed localized in the prefrontal cortex of each hemisphere. Also, in the right hemisphere, the source location of the CNVs was dependent on task, which supported the hypothesis of specialization of prefrontal function. The place recognition task was associated with more anterior and inferior CNV sources than the pattern recognition task. Finally, it was observed that ECDs for the warning period CNVs were indistinguishable from those for the test period of the tasks.

Comparison of single current dipole and magnetic field tomography analyses of the cortical response to auditory stimuli

Measurements of the magnetic field elicited by a 50 ms long auditory stimulus, from three normal subjects and one head injured subject, are used to estimate the three dimensional distribution of generators in the brain. The resulting images are compared with point source solutions obtained with the usual single current dipole fitting procedures, over a latency range which includes the extrema in the (average) measured signal. In all cases considered, 100 or so epochs time-locked to the stimulus were magnetically recorded. These were averaged, and then analyzed using two techniques; a new distributed current model known as Magnetic Field Tomography (MFT), and the standard single current dipole (SCD) model. Both methods provide estimates of the current generators in the brain. In two of the normal subjects, the MFT solutions are super-imposed onto Magnetic Resonance Images (MRI) of the relevant cortical area. The results show that when the SCD model provides a reasonable description of the data, the MFT estimate shows one dominant localized region in agreement with the current dipole position. In the MFT sequence of solutions the activity evolves smoothly; multiple areas of activity often arise as the focal activity in one region declines while focal activity in another region grows. In contrast the SCD solutions during these intermediate periods fit the data poorly, and may move erratically from one locale to another. We conclude that MFT seems to provide a reasonable description of the activity through cortical and subcortical regions. The evolution of activity, as derived from the average signal, can be traced continuously from the onset of the stimulus, not just at the peaks.(ABSTRACT TRUNCATED AT 250 WORDS)

Visual evoked magnetic fields reveal activity in the superior temporal sulcus

Evoked magnetic fields to randomized infrequent omissions of visual stimuli resulted in a magnetic field pattern over the right hemisphere consistent with a dipolar source and led to localization of this source within the superior temporal sulcus. Previous investigations using implanted microelectrodes, ablation/lesion procedures in monkeys and observations of behavioral anomalies following injury in humans have already indicated the importance of the inferior portions of the temporal lobe in visual processing. However, until now, no method was available to study noninvasively the role of temporal cortex during visual processing.

Magnetoencephalography reveals two distinct sources associated with late positive evoked potentials during visual oddball task

The present investigation was undertaken in order to utilize magnetoencephalography to locate generator sources, modeled as equivalent current point dipoles, that account for the well-established late positive electrical potentials commonly measured along the midline (Cz, Pz, Fz, and Oz) in response to rare or task-relevant stimuli and their simultaneously recorded magnetic field components. Two simultaneous but spatially distinct sources were present in all six subjects. One source in which the magnetic flux exited and reentered the brain over the right hemisphere was localized in deep structures under the temporal cortex in the vicinity of the right hippocampal formation. The other occurred in the vicinity of the primary visual cortex in the occipital area with magnetic flux entering and exiting over the posterior aspects of the subjects' heads. These data correspond to depth and surface electrode studies that have demonstrated multiple generator sources.

Late magnetic fields and positive evoked potentials following infrequent and unpredictable omissions of visual stimuli

Randomized and infrequent omissions during presentation of a steady train of visual stimulation produced distinctive wave forms of both the magnetic fields and electrical potentials. Electrical potentials at Pz showed a positive peak in response to the omitted stimuli which occurred on the average 445 msec after the time when a stimulus was anticipated. Analyses of the magnetic wave forms indicated that at least two separate sources appear to be active coincident with the electrical positive peak. One source localized in the occipital lobes in the vicinity of the visual cortex while the other source was located in the medial aspects of the temporal lobe or even deeper in the lateral thalamus. Judging from the calculated direction of current flow it appeared that the deep source would contribute greater potentials in the frontal areas of the scalp while the source in the occipital area would contribute to more posterior placement of electrodes, especially at Pz.

Localization of the P3 sources using magnetoencephalography and magnetic resonance imaging

In this study, two related issues were addressed: first, whether the P3 component of auditory evoked responses, obtained in the context of an oddball paradigm, and its magnetoencephalographically recorded counterpart (P3m) are generated by the same intracranial sources; and, second, whether these sources, modeled as equivalent current dipoles, can be localized in particular brain structures using magnetic resonance imaging. The study involving 8 normal adult subjects resulted in the following findings. (1) Both the similarities and differences in wave form characteristics of the simultaneously recorded P3 and P3m can be best accounted for by common intracranial sources. (2) Several successively activated single-dipolar sources, rather than a single source, account for the entire evolution of the P3m component. (3) Most of these sources were localized in the vicinity of the auditory cortex in all subjects, although some sources appeared to be in deeper structures, possibly the lateral thalamus. (4) The successive activation of sources followed an orderly medial-to-lateral course. These results suggest that activity responsible for the surface-recorded P3 (and P3m) component may be initiated in deep structures, but it quickly spreads over and is sustained in areas near the auditory cortex.

Magnetoencephalographic localization of interictal spike sources. Case report

The reliability of localization of interictal spike sources using magnetoencephalography (MEG) was examined by repeated measurements in a patient with temporal lobe epilepsy. During two preoperative recording sessions, the estimated sources, projected onto magnetic resonance images of the patient's brain, were found to lie less than 1 cm apart within the area subsequently resected. The MEG localization was in close agreement with intraoperative cortical recordings.

Gender differences in source location for the N100 auditory evoked magnetic field

Auditory evoked magnetic fields were recorded in response to contralateral stimulation over the right hemisphere in 6 adult males and 6 adult females. The data were fit to a model of a current-dipole source in a homogeneous sphere and 5 parameters of the dipole were computed--3 spatial coordinates, orientation, and strength. When average values for the dipole parameters were compared between sexes, it was found that the current source for the N100m is located more than 1 cm posterior in females and is oriented pointing more downward. These findings were replicated in separate measurement sessions. Viewing of individual magnetic resonance images did not reveal a corresponding anatomical disparity in the location of the primary auditory cortex which is assumed to produce the N100m. Therefore, functional organization of the auditory cortex may be different for the sexes.

Cerebral magnetic resonance imaging compared in Alzheimer's and multi-infarct dementia

Cerebral magnetic resonance images (MRI) were compared between two groups, each of 25 patients, one with senile dementia of the Alzheimer's type (SDAT) and the other with multi-infarct dementia (MID). MRI proved to be clinically useful for differentiating SDAT from MID, utilizing a multivariate model of six MRI criteria as follows: ventricular-brain ratio, presence of subcortical infarcts, bifrontal ventricular ratio, bicaudate ventricular ratio, third ventricular ratio, and presence of diffuse periventricular high-intensity white matter lucencies. Utilizing all six MRI criteria, classification by discriminant function analysis provided 84% correct diagnostic agreement with clinical classification of MID patients, 92% for SDAT patients, and 88% for the total cohort of demented patients.

Neuromagnetic evidence of a dynamic excitation pattern generating the N100 auditory response

Evoked magnetic field recordings were used to localize multiple sources of the negative component of cortical responses to auditory stimuli. The negative cortical component of the auditory evoked response, often called the N100, has traditionally been of interest due to its sensitivity to both stimulation parameters and cognitive variables. Results indicate that this component appears to reflect spreading activation of adjacent cortical columns within the primary projection area of the temporal lobe, extending anteriorly for about 1 cm following the downward slope of the superior surface of the lobe.

After reaching retirement age physical activity sustains cerebral perfusion and cognition

Among neurologically normal volunteers approaching age 65 with an option for retirement, a four-year prospective longitudinal study was designed to examine effects of different levels of physical activity on cerebral perfusion by between-group comparisons. After the fourth year, cognitive performance was also tested. Three groups were compared, each composed of 30 elderly volunteers, assigned as follows: Group 1, who continued to work; Group 2, who retired but participated in regular physical activities; and Group 3, who retired but did not participate in regular, planned physical activities. Retirees who elected to become physically inactive exhibited significant declines in cerebral blood flow (CBF) throughout four years of follow-up. Those who continued to work or retirees who elected to participate in regular activities sustained more constant CBF levels. Active retirees and those who continued to work also scored better on cognitive testing after the fourth year of follow-up compared to inactive retirees.

Source localization of two evoked magnetic field components using two alternative procedures

The purpose of this study was to compare the relative efficacy of two methods in assessing the location of the sources of the N100 and P200 components of evoked magnetic fields (EMFs) to transient tone stimuli. EMFs to left ear stimulation, containing both components, were recorded over the right hemisphere of six normal subjects. The magnetic scalp distributions calculated at several adjacent time points, covering the duration of each component's peak, were used to estimate the source parameters of each component. Good estimates of the source of both components were obtained from all magnetic field distributions. The averaged spatial parameters derived from all distributions of each component as well as the parameters derived from the distribution that gave the best source estimate for each component were projected onto magnetic resonance images of subject's head. It was found that the source of each component is located on the superior surface of the temporal lobe and that the source of the P200 component is anterior to the N100 source in all subjects using both procedures.

Intersession replicability of dipole parameters from three components of the auditory evoked magnetic field

The replicability of dipole localizations between sessions in an unselected group of subjects was studied. Auditory evoked magnetic fields (AEMFs) in response to contralaterally and ipsilaterally presented 1 kHz tone bursts were recorded from the right hemisphere of 12 subjects with normal hearing in two replicate sessions several days apart. Three long-latency components of the AEMF were studied, occurring at latencies near 50 msec (P1m), near 100 msec (N1m) and near 165 msec (P2m). A spherical model of the head was used to fit equivalent-current dipoles to the data. Statistical analysis of dipole parameters revealed virtually no differences between the two testing sessions. The variability between sessions had a mean absolute difference of 3 to 10 mm for the spatial parameters. Comparison of dipole parameters between components showed that there was a replicable, but nonsignificant, trend for a difference in the location of the N1m from contralateral vs. ipsilateral stimulation, and a statistically significant confirmation that the P2m is located anterior to the N1m for contralateral stimulation. Magnetic resonance images from each subject were used to locate the dipoles near the primary auditory cortex in the Sylvian fissure.

Localization of auditory response sources using magnetoencephalography and magnetic resonance imaging

Magnetoencephalography offers the possibility of localizing accurately and noninvasively the source of intracranial currents associated with normal and abnormal brain activity. The purpose of this study was to assess the validity and across-subject reliability of localization of cortical sources responding to ipsilateral and contralateral auditory stimulation. Magnetic evoked fields to both stimulation conditions were measured in eight consecutive normal subjects, and the cortical sources of these fields were estimated on the basis of these measurements. Subsequent projection of the source location coordinates onto magnetic resonance images showed that in all subjects the sources were accurately estimated to fall in the vicinity of the auditory cortex and that two separate sources may account for the response to ipsilateral and contralateral stimulation.

Randomized clinical trial of daily aspirin therapy in multi-infarct dementia. A pilot study

Seventy multi-infarct dementia patients were randomized into an aspirin-treated group and an untreated control group for an exploratory investigation to determine any effects of 325 mg aspirin daily on cognitive performance. The control group did not receive placebo but evaluations were carried out in a blinded manner. The index group (N = 37, mean age 67.1 years) received 325 mg of aspirin by mouth once daily while the control group (N = 33, mean age 67.6 years) was followed and treated in a similar manner except that they received no aspirin. Both groups had comparable risk factors for stroke, which were treated similarly, as well as comparable initial cerebral blood flow values, as measured by the 133xenon inhalation method, and initial scores on Cognitive Capacity Screening Examination testing. Patients were evaluated at intervals of one year. Significant improvements were demonstrated for cerebral perfusion values (P less than .0001) and cognitive performance scores (P less than .0001) among aspirin-treated patients compared to untreated controls at each of three annual follow-up evaluations. Both men and women benefited from aspirin therapy and their quality of life and independence appeared to be improved, which was not apparent in the control group. Daily aspirin appears to improve or stabilize declines in cerebral perfusion and cognition among patients with multi-infarct dementia.

Reducing hypertriglyceridemia in elderly patients with cerebrovascular disease stabilizes or improves cognition and cerebral perfusion

Effects of lowering serum triglyceride levels were investigated among 44 elderly hypertriglyceridemic patients with risk factors for stroke, reduced cerebral perfusion, and a history compatible with symptomatic occlusive cerebrovascular disease. Patients were randomly assigned to either treatment with gemfibrozil, a lipid-lowering agent, or control conditions. Subjects in both groups were instructed to follow a diet recommended for lowering serum lipid levels, while the treatment group was additionally administered 600 mg daily of gemfibrozil. Subjects assigned to the treatment group (n = 22) showed significant reductions in serum triglyceride levels (p less than .0005). Control subjects (n = 22) did not show any significant changes in serum triglyceride levels. There were also no significant changes in total cholesterol levels in either group. Analyses of values for mean bihemispheric gray matter cerebral blood flow measured by the xenon 133 inhalation method and cognitive scores tested by the Cognitive Capacity Screening Examination indicated that gemfibrozil-treated patients maintained significantly higher levels of cerebral perfusion and cognitive performance than untreated controls did. Regression analyses for different treatment intervals indicated that both cerebral blood flow and cognition showed linear improvements that correlated directly with the duration of treatment. Lowering triglyceride levels in hyperlipidemic subjects appears to benefit cerebral perfusion and cognitive performance after four to six months.

Aetiological considerations and risk factors for multi-infarct dementia

One hundred and seventy five multi-infarct dementia (MID) patients were evaluated for risk factors for stroke as well as for the types of cerebrovascular lesions that were present. The incidence of associated risk factors for stroke were as follows: hypertension (66%), heart disease (47%), cigarette smoking (37%), diabetes mellitus (20%), moderate alcohol consumption (19%) and hyperlipidaemia (21%). The most frequently occurring type of lesions were multiple lacunar infarctions of the brain (43%). These were combined with other types of stroke in an additional 21%. Atherosclerotic occlusive disease of the carotid and vertebrobasilar arteries occurred alone in 18% and was associated with other types of stroke in another 25%. Embolic cerebral infarctions were present alone in 8% and were combined with other types of stroke in 15%. MID was more frequent in men (62%) than women (p less than 0.002). Mean bihemispheric gray matter cerebral blood flow (CBF) values showed a fluctuating course and when results were pooled and compared between different types of MID, extracranial occlusive disease and/or multiple lacunar infarctions resulted in lowest CBF values. The location of cerebral infarctions was more importantly related to cognitive impairments than was the total volume of infarcted brain. Mortality rates among 125 MID patients followed for 31 months has been 5%. Correct clinical classification of the types of cerebrovascular lesions was confirmed in three necropsied cases.

Cognition and cerebral blood flow fluctuate together in multi-infarct dementia

Longitudinal measurements of cognitive ability measured by serial testing using the Cognitive Capacity Screening Examination (CCSE) were correlated with cerebral blood flow (CBF) throughout (mean +/- SD) 19.9 +/- 12.6 months among 57 patients with multi-infarct dementia, 17 with dementia of the Alzheimer's type, 10 with both, and among 32 age-matched elderly normal controls. Longitudinal CCSE and CBF measurements among controls yielded stable normative values. Reduced mean CCSE scores correlated directly with CBF reductions in patients with multi-infarct dementia (p less than 0.0005) and dementia of the Alzheimer's type (p less than 0.028). Patients with multi-infarct dementia had CCSE scores with retest variability exceeding those of controls (p less than 0.001) and of patients with dementia of the Alzheimer's type (p less than 0.003). CCSE scores and CBF changed together 78.6% (p less than 0.001) of the time in patients with multi-infarct dementia compared with 66.2% of the time (p less than 0.01) in those with both, 62.9% of the time (p less than 0.05) in those with dementia of the Alzheimer's type, and 47.7% of the time (NS) in controls. Further analyses indicated that changes in CCSE scores and CBF were predominantly progressive declines in patients with dementia of the Alzheimer's type, whereas the changes were more bidirectional (both increases and decreases) in patients with multi-infarct dementia; these differences were also significant. Results support the diagnostic usefulness of the Hachinski ischemic scale and confirm that both cognition and CBF fluctuate together among patients with multi-infarct dementia, whereas patients with dementia of the Alzheimer's type exhibit a more stable course, with progressive declines in cognition and CBF.

Computerized history and self-assessment questionnaire for diagnostic screening among patients with dementia

In order to standardize and quantify diagnostic information derived from medical histories and case reports given by demented patients, their families or care-providers, a questionnaire has been developed containing 94 questions. The output is categorized by computer into graphic clinical scales which correlate and weigh information relating to seven of the most common causes of dementia. The present investigation assesses the validity of predictive diagnostic classifications derived from the clinical scales tested on admission by correlating them later with final diagnoses determined independently by thorough clinical evaluation including standard diagnostic tests, computed tomography and nuclear magnetic resonance scans. Results of 101 healthy, neurologically normal, age-matched volunteers and 140 patients representative of the more common forms of dementia indicate that correct diagnostic identification was: 75% for dementia secondary to Parkinson's disease, 100% for Huntington's disease, 90.2% for Alzheimer's disease, 82.4% for multi-infarct dementia, 90.0% for posttraumatic dementia, 77.8% for normal-pressure hydrocephalus and 85.7% for Wernicke-Korsakoff dementia. Correct diagnostic assignment was highly significant (P less than .0005). The screening questionnaire may prove to be a useful and standard diagnostic tool for clinicians and investigators concerned with epidemiology, prevention and treatment of dementia.

Hyperlipidemia is a risk factor for decreased cerebral perfusion and stroke

Possible effects of chronically elevated serum cholesterol and triglyceride levels on measurements of cerebral blood flow were investigated by between-group comparisons of individuals, with and without hyperlipidemia, among 56 neurologically normal elderly volunteers and among 102 age-matched patients with symptoms of transient ischemic attacks (TIAs). Results demonstrated significantly higher levels of serum cholesterol and triglyceride among the TIA patients compared with randomly selected age-matched normal controls of similar educational and environmental backgrounds. Cerebral blood flow levels were reduced among groups of TIA patients with elevated levels of either cholesterol or triglycerides compared with the TIA patients with normal lipid levels. Similar trends were seen among normal volunteers, but these did not reach levels of statistical significance because of the limited numbers available. Analysis of frequency distributions for risk factors other than hyperlipidemia indicated that hypertension, atherosclerotic heart disease, diabetes mellitus, and cigarette smoking were also more prevalent among TIA patients than among age-matched normal controls.

Additional predisposing risk factors for atherothrombotic cerebrovascular disease among treated hypertensive volunteers

A 7-year prospective study of a cohort of 107 neurologically normal elderly hypertensive volunteers (mean age, 65.8 +/- 8.3 years) was undertaken to investigate the predictive validities of additional risk factors for atherothrombotic cerebrovascular disease including stroke, transient ischemic attacks, reversible ischemic neurological deficits, and multi-infarct dementia. This longitudinal study has been in progress now for 7 years with a mean follow-up interval of 50.12 +/- 5.76 months. Among 107 formerly symptom-free, normal hypertensive volunteers, 25 (23%) have developed cerebrovascular disease, 7 (6.5%) sustained a stroke, 10 (9.3%) developed multi-infarct dementia, and 18 (16.8%) have transient ischemic attacks. None have suffered intracranial hemorrhage. Mean gray matter cerebral blood flow (CBF) values measured at the initial visit were sensitive predictors of cerebrovascular disease. Eight of 16 hypertensives (50%) with initial CBF values below 60.0 ml/100 g/min now exhibit signs and symptoms of cerebrovascular disease, while 11 of 43 hypertensives (25.6%) with initial CBF values between 60.1 and 69.9 ml/100 g/min and only 6 of 48 (12.5%) with initial CBF levels above 70.0 developed cerebrovascular disease. Incidence of cerebrovascular disease among cigarette smoking hypertensive volunteers (32.5%) was significantly greater than among nonsmokers (17.2%).

Improved cognition after control of risk factors for multi-infarct dementia

A cohort of 52 patients (30 men and 22 women) with multi-infarct dementia (MID) has been followed up prospectively for a mean interval of 22.2 months. Clinical course has been documented by serial history taking and interviews and neurological, medical, and psychological examinations, and correlated with measurements of cerebral blood flow. The clinical course and cognitive performance have been compared with those of age-matched normal volunteers and patients with Alzheimer's disease. Patients with MID were subdivided into hypertensive and normotensive groups, and also into those displaying stabilized or improved cognition and those whose condition deteriorated. Among hypertensive patients with MID, improved cognition and clinical course correlated with control of systolic blood pressure within upper limits of normal (135 to 150 mm Hg), but if systolic blood pressure was reduced below this level, patients with MID deteriorated. Among normotensive patients with MID, improved cognition was associated with cessation of smoking cigarettes.

Cognitive performance correlates with cerebrovascular impairments in multi-infarct dementia

Cerebral blood flow (CBF) was measured by the 133Xe inhalation method in patients with multi-infarct dementia (MID, N = 26), Alzheimer's dementia (AD, N = 19), and among age-matched, neurologically normal, healthy volunteers (N = 26). Cognitive performance was assessed in all subjects using the Cognitive Capacity Screening Examination (CCSE). Cerebral vasomotor responses were calculated from differences in values of mean hemispheric gray matter blood flow (Delta CBF) measured during inhalation of 100% oxygen (hyperoxia) compared with CBF measured while breathing room air. Significant correlations were found between CCSE performance and vasomotor responsiveness in patients with MID (P less than .01), but not in patients with AD or in neurologically normal volunteers. Loss of vasomotor responsiveness is an indicator of cerebrovascular disease with rigidity and/or loss of reactivity of cerebral vessels, which impairs cerebrovascular responses to situational demands and predisposes to cerebral ischemia. Loss of cerebral vasomotor responsiveness among MID patients, which is a biologic marker of cerebrovascular disease, provides confirmatory evidence of the vascular etiology of MID and assists in separating MID from AD patients.