Adverse healthcare experiences are correlated with increased time to diagnosis in women with vulvar inflammatory dermatoses: a retrospective cohort survey

This retrospective cohort survey of over 300 women examined diagnostic delay in vulvar dermatoses compared with nonvulvar control conditions (e.g. psoriasis or atopic dermatitis). Adverse healthcare experiences (e.g. uncertainty of which provider to consult, embarrassment in talking to providers) occurred more often for participants with vulvar disease and were significantly correlated with increased time to diagnosis in this group, which was not the case in control conditions. The findings suggest opportunities to improve care for people with vulvar disease.

Enhancing Uterine Fibroid Care: Clinician Perspectives on Diagnosis, Disparities, and Strategies for Improving Health Care

Objective

To explore clinicians' perspectives on diagnosing, treating, and managing uterine fibroids, identifying gaps and challenges in health care delivery, and offering recommendations for improving care.

Materials and Methods

A qualitative design was used to conduct 14 semistructured interviews with clinicians who treat fibroid patients in central Indiana. Interviews were audio recorded, transcribed verbatim, and analyzed using thematic analysis techniques. Constant comparative analysis was used to identify emergent themes.

Results

Four themes emerged. (1) Lack of patient fibroid awareness: Patients lacked fibroid awareness, leading to challenges in explaining diagnoses and treatment. Misconceptions and emotional distress highlighted the need for better education. (2) Inequities in care and access: Health care disparities affected Black women and rural patients, with transportation, scheduling delays, and financial constraints hindering access. (3) Continuum of care: Clinicians prioritized patient-centered care and shared decision-making, tailoring treatment based on factors like severity, location, size, cost, fertility goals, and recovery time. (4) Coronavirus disease 2019 (COVID-19) impact: The pandemic posed challenges and opportunities, prompting telehealth adoption and consideration of nonsurgical options.

Conclusions

Clinician perspectives noted patient challenges with fibroids, prompting calls for enhanced education, interdisciplinary collaboration, and accessible care to address crucial aspects of fibroid management and improve women's well-being.

Practice Implications

Clinicians identified a lack of patient awareness and unequal access to fibroid care, highlighting the need for improved education and addressing disparities. Findings also emphasized the importance of considering multidimensional aspects of fibroid care and adapting to challenges posed by the COVID-19 pandemic, recommending broader education, affordability, interdisciplinary collaboration, and research for better fibroid health care.

Extracranial hypoglossal neurofibroma with a variant ansa cervicalis: a case report

PURPOSE

This case report aims to explore a rare combination of findings in a cadaver donor: variant ansa cervicalis, vagus (CN X) and hypoglossal (CN XII) nerve fusion, and extracranial hypoglossal neurofibroma.

BACKGROUND

The type of ansa cervicalis variation presented in this report has been documented in less than 1% of described cases. The CN X-CN XII fusion has been reported in one prior study. Additionally, hypoglossal neurofibromas are benign neoplasms of the peripheral nerve sheath. There are only two known cases of extracranial hypoglossal neurofibroma described in the literature.

CASE REPORT

The study investigated a swelling of the right CN XII in a 90-year-old female cadaver donor. Detailed dissection, examination of the region, and histopathological analysis of the mass followed. The entire course of CN XII and other cranial nerves were examined to exclude concurrent pathology. A fusiform enlargement of the right CN XII was observed in the submandibular region, measuring ~ 1.27 × 1.27 cm. The superior portion of the right CN XII was fused to the right CN X, exiting the jugular foramen. The superior root of ansa cervicalis, normally a branch of CN XII, was found to arise from CN X on the right side. The left CN XII and CN X were unremarkable. Histopathological examination revealed benign neurofibroma.

CONCLUSION

The anatomical variation and rare location of the tumor necessitate further investigation to better understand pathogenesis, clinical correlation, and surgical implications. This study furthers knowledge of this condition and contributes to the currently limited body of research.

"I think people should be more aware:" Uterine fibroid experiences among women living in Indiana, USA

OBJECTIVE

To understand healthcare experiences among patients with uterine fibroids (fibroids) across the continuum of care, from early symptoms through diagnosis, treatment, and management, while also investigating health disparities.

METHODS

We conducted 20 semi-structured interviews with patients with fibroids. Interviews were transcribed verbatim and qualitatively analyzed using thematic analysis. Eligible participants were women aged 18 and over, residing within 75 miles of one of the two recruitment locations (Tippecanoe or Marion County) in Indiana, USA.

RESULTS

Women experienced myriad physical symptoms, which often manifested into psychological and sexual disturbances and infiltrated all aspects of daily life. Internet searches were frequently mentioned as their main information source. Fertility became a prominent factor in deciding treatment options. However, health disparities prevented some from receiving quality fibroids healthcare. Some women reported staying home during COVID-19 pandemic facilitated the management of physical symptoms. Overall, participants advocated for greater fibroids awareness and education.

CONCLUSION

Results highlight barriers and facilitators to fibroids-related decisions, behaviors, and outcomes. Translation of research to practice was guided by a combined Social-Ecological Model and social determinants of health framework for development of strategic interventions.

PRACTICE IMPLICATIONS

Interventions should aim to improve fibroids healthcare access, education and awareness, and patient-provider communication for minority, rural, and low socioeconomic status communities disproportionately impacted by fibroids.

Genital Self-Image, Sexual Function, and Quality of Life Among Individuals with Vulvar and Non-Vulvar Inflammatory Dermatoses

Vulvar inflammatory dermatoses (VID; e.g., lichen sclerosus, lichen planus, vulvar dermatitis) can significantly impact sexual function. Both vulvar and non-vulvar inflammatory dermatoses (NVID; i.e., skin conditions not impacting vulvar skin, such as non-genital psoriasis and eczema/dermatitis) have yet to be fully characterized with regard to impact on genital self-image. A 20-min web-based survey was distributed September-November 2020 through social media ads, support groups, and online research recruitment services. Individuals in the USA over age 18 who were assigned female at birth and self-reported having been diagnosed with an inflammatory dermatosis were eligible. The primary outcome was the Female Genital Self-Image Scale (FGSIS). Secondary outcomes included the Female Sexual Function Index (FSFI), the Skindex-16 (a skin-related quality of life measure), the PROMIS Global-10 (assessing global physical/mental health), and sexual behavior histories. Participants (n = 348) reported mean age of 43.1 ± 15.5 (range = 19-81). Nearly one-third (n = 101; 29.0%) reported VID, 173 (50%) had NVID, and 74 (21%) experienced both vulvar and non-vulvar symptoms; they were analyzed as part of the VID group. The mean FGSIS score among participants with VID was 16.9 ± 4.1 and was significantly (p < .01) lower than that of participants with NVID (M = 21.2 ± 4.3), indicating lower genital self-image. Mental health (as measured by PROMIS-Global 10) was also impaired in VID. Rates of sexual dysfunction were high in both groups (> 60%). Findings suggest that in VID, lower genital self-image is correlated with poorer sexual function, quality of life, and global physical and mental health. Additional recommendations for VID management are proposed.

"Worse Than Disappointing": Prediagnostic Health Care Challenges of Women With Inflammatory Vulvar Dermatoses

OBJECTIVE

The purpose of this study was to investigate challenges women face before inflammatory vulvar dermatosis diagnosis to guide interventions for improving time to diagnosis and health care experiences.

MATERIALS AND METHODS

The present analysis was part of a larger study exploring sexual health and quality of life of women with vulvar and nonvulvar inflammatory dermatoses, evaluated via a 20-minute web-based survey. One open-response item asked participants to "briefly describe any challenges you faced with regards to health care or health care providers in the time when you were seeking a diagnosis"; this item informed the present study. Eligible participants were women older than 18 years, living in the United States, with diagnosis of an inflammatory vulvar dermatosis persisting at least 1 month. Participants (n = 118) had a mean age of 46.55 ± 15.35 years, and 64% (n = 75) had lichen sclerosus.

RESULTS

Provider-based challenges consisted of insensitive communication and ascribing physical symptoms to mental health issues, self-harm, or other factors. System-based challenges included confusing referral networks, limited specialist access, and widespread lack of provider education. Personal challenges for participants seeking care included feelings of embarrassment and reduced health care efficacy. Challenges led to emotional response and impact for participants, characterized by negative (e.g., distrust in the medical system) or positive (e.g., self-advocacy efforts, strong social media communities) outcomes.

CONCLUSIONS

Findings provide unique insights into the challenges women experience before inflammatory vulvar dermatosis diagnosis. This study creates new knowledge exploring the diagnostic journey accompanying inflammatory vulvar dermatoses and contributes practically to clinical and research needs of this understudied population.

Contextualising challenges of reproduction and motherhood in Florence, Italy: a qualitative study

Objectives: This study sought to understand attitudes, behaviours and expectations regarding reproductive planning, infertility and motherhood among women living in Italy.Methods: Researchers conducted 55 in-depth interviews among 46 reproductive-aged women living in or around Florence, Italy, currently using the Italian health care system, and nine Italian health care professionals. Researchers used an expanded grounded theory approach to understand women's reproductive experiences, with the social-ecological model serving as a conceptual lens for data analyses.Results: Fertility care inadequacy and financial instability impacted participants' attitudes towards reproduction. Women's shifting roles and reduced marital salience prompted decisions to delay or forgo childbearing. For pregnant women and women with children, perceived postpartum challenges included employment discrimination, childrearing costs and variable paternal support. Some participants discussed increased parental responsibility sharing, but many noted lingering expectations that women prioritise motherhood above other pursuits.Conclusion: Findings provide insight into Italian women's reproductive attitudes and behaviours and the declining fertility rate in the current economic and social environment. Practical recommendations for policy and socio-cultural interventions should address reproductive barriers such as affordable childcare, improved fertility assistance, maternal employment protection, and better utilization of existing support structures.

A back translation of pregabalin and carbamazepine against evoked and non-evoked endpoints in the rat spared nerve injury model of neuropathic pain

The purpose of the present study was twofold. First to characterize endpoints distinct to the reflexive responses to sensory stimuli typically used in neuropathic pain models. A second aim was to evaluate two clinically approved drugs carbamazepine (Tegretol) and pregabalin (Lyrica) against these endpoints with the purpose to backtranslate from the clinical to preclinical setting. The selected neuropathic pain model was the spared nerve injury (SNI) model and the endpoints were burrowing and measures of paw posture in Sprague Dawley rats. As previously described, SNI surgery produced a robust heightened sensitivity to tactile and thermal (cold) stimuli. SNI surgery also produced robust decreases in burrowing and affected multiple measures of paw position. There was no correlation between magnitude of change in burrowing and sensory allodynia within SNI operated rats. Pregabalin (10-30 mg/kg IP) produced a reliable reversal of both tactile and cold allodynia and also the burrowing deficit, with minimal effect on neurological function evaluated using rotorod, beam walking and open field activity. Pregabalin did not affect any measure of paw position. Pharmacokinetic studies conducted in satellite animals identified plasma levels of pregabalin at the 10 mg/kg IP dose to be equivalent to clinically efficacious levels recorded in neuropathic patients (3-6 μg/ml). In contrast carbamazepine (10-60 mg/kg IP) had only a very modest effect against a reflexive (tactile) measure, and no effect against the burrowing deficit. Carbamazepine also affected various measures of neurological function, complicating interpretation of the reflexive measure. Measurement of burrowing appears to detect a behavioural deficit associated with the SNI model, that may be attenuated by pregabalin but not carbamazepine. Overall the present findings support an advantage of pregabalin over carbamazepine in terms of both efficacy and tolerability which is consistent with clinical experience. The inclusion of additional endpoints beyond traditional reflexive behaviours further supports the value of rodent neuropathic pain models, such as the SNI, as behavioural assays to detect new chemical entities to treat this pain condition.

Graves' disease during immune reconstitution after highly active antiretroviral therapy for HIV infection: evidence of thymic dysfunction

A patient with HIV infection who experienced immune reconstitution after highly active antiretroviral therapy (HAART) [increase in CD4 T cell count from <1/microl to >600/microl] presented with severe Graves' disease 32 months after commencing HAART. A comprehensive clinical and laboratory study demonstrated pronounced regional lymphadenopathy and thymic enlargement at presentation, and that the onset of thyrotropin receptor antibody production was associated with increased production of soluble CD30 (a marker of type 2 immune responses). Blood naive CD8 T cell counts and TREC levels in both CD4 and CD8 T cells were increased at multiple time points compared with carefully selected controls. We conclude that the Graves' disease in this patient was associated with abnormally high blood counts of thymus-derived T cells, and propose that Graves' disease after HAART in this and other HIV patients may result from failure to delete autoreactive T cell clones in the regenerating thymus.

A treatment planning inter-comparison of proton and intensity modulated photon radiotherapy

PURPOSE

A comparative treatment planning study has been undertaken between standard photon delivery techniques,b intensity modulated photon methods and spot scanned protons in order to investigate the merits and limitations of each of these treatment approaches.

METHODS

Plans for each modality were performed using CT scans and planning information for nine patients with varying indications and lesion sites and the results have been analysed using a variety of dose and volume based parameters.

RESULTS

Over all cases, it is predicted that the use of protons could lead to a reduction of the total integral dose by a factor three compared to standard photon techniques and a factor two compared to IM photon plans. In addition, in all but one Organ at Risk (OAR) for one case, protons are predicted to reduce both mean OAR dose and the irradiated volume at the 50% mean target dose level compared to both photon methods. However, when considering the volume of an OAR irradiated to 70% or more of the target dose, little difference could be shown between proton and intensity modulated photon plans. On comparing the magnitude of dose hot spots in OARs resulting from the proton and IM photon plans, more variation was observed, and the ranking of the plans was then found to be case and OAR dependent.

CONCLUSIONS

The use of protons has been found to reduce the medium to low dose load (below about 70% of the target dose) to OARs and all non-target tissues compared to both standard and inversely planned photons, but that the use of intensity modulated photons can result in similar levels of high dose conformation to that afforded by protons. However, the introduction of inverse planning methods for protons is necessary before general conclusions on the relative efficacy of photons and protons can be drawn.

Characterization of dose distribution in radiation therapy plans

As a method of considering only significant radiation doses to different tissues, the ICRU Report 50 recommends taking the dose given to a significant tissue volume (minimum diameter greater then 15 mm) instead of choosing a single, potentially insignificant, voxel value. In order to find this significant volume, we have adapted an emission imaging analysis method to radiation therapy planning. The resulting method finds and characterizes the dose distribution in the volumes of interest in a way that includes spatial arrangement. The data can be used to signal significant hot or cold volumes in the dose plan and to score the plans based on significant dose to the tissues.

Acute thermal hyperalgesia in the rat is produced by activation of N-methyl-D-aspartate receptors and protein kinase C and production of nitric oxide

There is general agreement that activation of the N-methyl-D-aspartate receptor is involved in thermal hyperalgesia. However, there is less agreement on the specific intracellular events subsequent to receptor activation and the involvement of other excitatory amino acid receptors in thermal hyperalgesia. In the present study, we found that the intrathecal administration of N-methyl-D-aspartate produced a dose- (1 fmol-1 pmol) and time-dependent thermal hyperalgesia. In contrast, over the dose range tested, intrathecal administration of either alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionate (AMPA; 10 fmol-100 pmol), 1,3-trans-1-aminocyclopentyl-1,3-dicarboxylate (10 fmol-100 pmol), quisqualate (10 pmol-5 nmol) or a 1:1 combination of AMPA and 1,3-trans-1-aminocyclopentyl-1,3-dicarboxylate (total dose 20 fmol-200 pmol) did not produce any evidence of thermal hyperalgesia; greater doses produced a caudally-directed biting and scratching behavior that precluded testing in the paradigm used. A fixed dose of 1,3-trans-1-aminocyclopentyl-1,3-dicarboxylate (100 pmol) did, however, potentiate the effects of N-methyl-D-aspartate (1-100 fmol). Thermal hyperalgesia produced by N-methyl-D-aspartate (1 pmol) was attenuated by intrathecal administration of the N-methyl-D-aspartate receptor-selective antagonist 2-amino-5-phosphonopentanoate (100 pmol), but not by the AMPA receptor-selective antagonist 6,7-dinitroquinoxaline-2,3-dione (1 nmol) or the metabotropic receptor antagonist 2-amino-3-phosphonoproprionate (10 nmol). In a second series of experiments, we examined the role of different signal transduction systems in acute N-methyl-D-aspartate-produced thermal hyperalgesia. N-Methyl-D-aspartate-produced thermal hyperalgesia (1 pmol) was attenuated by intrathecal hemoglobin (1-100 pmol) and dose-dependently by intrathecal N(G)-nitro-L-arginine methyl ester (10 pmol-l nmol), Methylene Blue (10 pmol-l nmol) and chelerythrine (1-100 pmol), suggesting that acute N-methyl-D-aspartate-mediated thermal hyperalgesia involves activation of nitric oxide synthase and protein kinase C. In contrast, N-methyl-D-aspartate-produced thermal hyperalgesia was unaffected by intrathecal administration of the phospholipase A2 inhibitor mepacrine (10 nmol) or the phospholipase C inhibitor neomycin (10 nmol). While prostaglandins and leukotrienes have been suggested to play a role in hyperalgesia, N-methyl-D-aspartate-produced thermal hyperalgesia (1 pmol) was unaffected by the non-selective eicosanoid inhibitor nordihydroguaiarate (1 nmol), the cyclo-oxygenase selective inhibitor indomethacin (10 nmol) or the lipoxygenase selective inhibitor baicalein (1 nmol). The results of the present study suggest that acute thermal hyperalgesia can be produced by activation of N-methyl-D-aspartate receptors. Activation of AMPA, metabotropic or co-activation of AMPA and metabotropic glutamate receptors, at the doses tested, did not produce an acute thermal hyperalgesia. The thermal hyperalgesia produced by N-methyl-D-aspartate is mediated by activation of nitric oxide synthase and protein kinase C, but not by phospholipase C, phospholipase A2, cyclo-oxygenase or lipoxygenase. Collectively, the results are consistent with a role for spinal N-methyl-D-aspartate receptors, nitric oxide and protein kinase C in thermal hyperalgesia.

Anti-Pneumocystis carinii pneumonia activity of dicationic 2,4-diarylpyrimidines

A synthesis of 2,4-bis-(4-amidinophenyl)pyrimidine 6, 2,4-bis-[(4-imidazolin-2-yl)phenyl)]pyrimidine 7, 2,4-bis [(4-tetrahydropyrimidinyl-2-yl)phenyl]pyrimidine 8, 2,4-bis[(4-N-n-propylamidino)phenyl]pyrimidine 9, 2,4-bis[(4-N-isopropylamidino)-phenyl]pyrimidine 10 and 2,4-bis[(4-N-isobutylamidino)phenyl]pyrimidine 11 starting from 4-bromobenzamidine and 4-bromoaceto-phenone is reported. A synthesis of 2-(4-amidinopnenyl)-4-(2-methoxy-4-amidinophenyl)pyrimidine 20, 2-[4-(imidazolin2-yl)-phenyl]-4-[2-me thoxy-4-(imidazolin-2-yl)phenyl]pyrimidine 21, and 2-[4-(N-iso-propylamidino)phenyl]-4-[2-methoxy-4-(N-isopro-pylamidino)phenyl]pyrimidine 22 beginning with 4-bromobenzamidine and 2-methoxy-4-bromoacetophenone is described. Compounds 6-11 and 20-22 all bind strongly to DNA. Compounds 6, 9-11, and 20 given at 5 mg/kg are more active and less toxic than pentamidine at its effective dose when evaluated against Pneumocystis carinii pneumonia (PCP) in the immunosuppressed rat model. Several compounds in this series are being evaluated further as potential new anti-PCP agents.

The possible role of glia in nociceptive processing and hyperalgesia in the spinal cord of the rat

Recent studies have suggested that glia might play a more active role in synaptic function than previously thought. Therefore, the present studies have evaluated the potential role of spinal cord glia in acute nociceptive processing and in the thermal and mechanical hyperalgesia produced by peripheral injury. In the present experiments, we found that: (1) selective inhibition of glia metabolism with intrathecal (i.t.) administration of fluorocitrate (1 nmol) results in a marked, but reversible, attenuation of the persistent thermal and mechanical hyperalgesia produced by intraplantar zymosan (5 mg); (2) selective inhibition of the inducible form of nitric oxide synthase (iNOS) with i.t. aminoguanidine (1 pmol-1 nmol) resulted in a dose-dependent inhibition of the persistent thermal, but not mechanical hyperalgesia produced by intraplantar zymosan (5 mg); (3) i.t. coadministration of interleukin 1 beta (IL1 beta; 10 ng) and interferon gamma (IFN; 1000 U) resulted in expression of the message for iNOS 8 hr after administration assessed using reverse-transcription polymerase chain reaction (RT-PCR) and Southern blot analysis; and (4) i.t. administration of lipopolysaccharide (LPS; 150 micrograms) produced a time-dependent thermal hyperalgesia compared with saline treated-rats (15 microliters). There was no change in mechanical withdrawal thresholds over time following any treatment, except fluorocitrate. We have previously shown that NO plays a significant role in mechanisms of hyperalgesia. In the present experiments we have extended these observations and have now shown a role for iNOS, expressed by glia, in mechanisms of hyperalgesia. These results suggest an unexplored avenue for the development of potential new and novel therapies for pain control.

Ethanol dose-dependently attenuates NMDA-mediated thermal hyperalgesia in the rat

Recent observations using acute and persistent pain models have suggested that activation of the N-methyl-D-aspartate (NMDA) receptor is required for mechanisms that underly the development and maintenance of thermal hyperalgesia. The present results document that both NMDA-mediated thermal hyperalgesia produced after acute intrathecal NMDA administration and NMDA-mediated thermal hyperalgesia produced in a model of neuropathic pain are dose-dependently and reversibly attenuated by intrathecal administration of ethanol (0.5-1.0%; total dose, 106-213 nmol, i.t.). This is consistent with recent reports that ethanol may function as a selective NMDA receptor antagonist at low concentrations and further extends the evidence that thermal hyperalgesia is mediated by NMDA receptors.

Pneumocystis carinii induction of tumor necrosis factor-alpha by alveolar macrophages: modulation by pentamidine isethionate

Pneumocystis carinii, and the inflammatory response it provokes, together contribute to irreversible lung damage in immunocompromised patients. P. carinii cysts were found to be capable of inducing tumor necrosis factor-alpha (TNF) release from alveolar macrophages in a concentration-dependent manner. At physiologically achievable concentrations, pentamidine isethionate (pentamidine) substantially reduces such production. Pretreatment of alveolar macrophages (AM phi) with interferon-gamma (IFN-gamma) synergizes with P. carinii to produce increased levels of TNF, a condition which pentamidine was also able to antagonize. Pentamidine treatment did not interfere with the phagocytic ability of AM phi. Considering clinical reduction of TNF could lessen P. carinii pneumonia (PCP) induced inflammation, the efficacy of pentamidine in the treatment of PCP may be partially associated with its ability to inhibit the release of inflammatory mediators such as TNF.

Production of endogenous nitric oxide and activation of soluble guanylate cyclase are required for N-methyl-D-aspartate-produced facilitation of the nociceptive tail-flick reflex

The intrathecal (i.t.) administration of either N-methyl-D-aspartate (NMDA, 10 fmol to 10 pmol) or L-arginine (1 pmol to 10 nmol), but not D-arginine (1 pmol to 10 nmol), produced a rapid, transient, dose-dependent facilitation (maximal response of 30.9 +/- 6.0% and 33.7 +/- 1.5%, respectively) of the nociceptive tail-flick reflex (ED50 = 47.8 +/- 15.4 fmol and 11.4 +/- 2.7 pmol, respectively). Maximal NMDA-produced facilitation of the tail-flick reflex (1 pmol i.t.) was completely abolished by prior treatment (10 min prior) with either N omega-nitro-L-arginine methyl ester (L-NAME, 10 nmol i.t.), methylene blue (10 nmol i.t.) or DL-5-aminophosphonovaleric acid (AP5, 100 pmol i.t.). NMDA-produced facilitation was completely recovered 40 min after L-NAME, 50 min after methylene blue and 30 min after AP5. L-NAME, methylene blue or AP5 did not significantly alter baseline tail-flick latency. These results suggest that NMDA-produced facilitation of a thermal nociceptive reflex is mediated through activation of an NMDA receptor that results in an increase in endogenous nitric oxide and activation of soluble guanylate cyclase in lumbar spinal cord.

EEGs: a closer look at a familiar diagnostic test

Neuroscience nurses frequently care for patients scheduled to have an electroencephalogram (EEG). Although nurses are involved in teaching the patient about the procedure, most have only a rudimentary understanding of the underlying physiology or purpose of the test, or of the actual testing procedure. This article discusses these issues as well as material for patient teaching, and the use of EEG monitoring by nurse researchers.

The magnetoencephalographic localisation of source-systems in the brain: early and late components of event related potentials

The application of magnetoencephalography (MEG) to the analysis of sources in the brain responsible for early and late components of evoked potentials is discussed. Representative data are presented and discussed which demonstrate localisation of sources assuming single equivalent dipoles. Distributed systems as sources for some steady-state responses are discussed in relation to the broader issue of the usefulness of equivalent single dipole models. These issues are related to the use of MEG for the analysis of source systems influenced by alcohol and other drugs.