Stalkers: Specialists Versus Generalists

AbstractIt is known that many domestic violence (DV) offenders also commit violent and nonviolent offences that are not domestic in nature. Stalking frequently evolves from DV contexts. The present study used police data to explore (i) the extent to which stalking offenders in Western Australia specialize in stalking, (ii) the frequency of involvement in DV offending by stalking offenders, and (iii) the types of offences that co-occur with stalking offences. The dataset covered 404 individuals who were identified by the Western Australia Police Force as the offender for a stalking offence between January 1st, 2003 and July 30th, 2017. Only a minority of the offenders specialized in stalking, with the majority offending in other ways against the index victim and also offending against others via a broad range of offences. Although less than 10% were recorded as having carried out domestic assaults, more than half had broken restraining orders. Like DV offenders, the stalkers in this sample were largely generalist offenders. It was not clear, however, what proportion of offences against the same index victim were directly related to stalking. Stalking is a course of conduct that often involves individual acts that may be offences in themselves. What is clearer is the finding that for many stalkers, stalking forms part of a wider pattern of antisocial activity. Those stalkers who do not specialize in stalking may be less likely to benefit from intervention efforts that are focused solely on stalking.

Human interictal epileptiform discharges are bidirectional traveling waves echoing ictal discharges

Interictal epileptiform discharges (IEDs), also known as interictal spikes, are large intermittent electrophysiological events observed between seizures in patients with epilepsy. Although they occur far more often than seizures, IEDs are less studied, and their relationship to seizures remains unclear. To better understand this relationship, we examined multi-day recordings of microelectrode arrays implanted in human epilepsy patients, allowing us to precisely observe the spatiotemporal propagation of IEDs, spontaneous seizures, and how they relate. These recordings showed that the majority of IEDs are traveling waves, traversing the same path as ictal discharges during seizures, and with a fixed direction relative to seizure propagation. Moreover, the majority of IEDs, like ictal discharges, were bidirectional, with one predominant and a second, less frequent antipodal direction. These results reveal a fundamental spatiotemporal similarity between IEDs and ictal discharges. These results also imply that most IEDs arise in brain tissue outside the site of seizure onset and propagate toward it, indicating that the propagation of IEDs provides useful information for localizing the seizure focus.

Evaluation of procalcitonin as a contribution to antimicrobial stewardship in SARS-CoV-2 infection: a retrospective cohort study

It can be a diagnostic challenge to identify patients with coronavirus disease 2019 in whom antibiotics can be safely withheld. This study evaluated the effectiveness of a guideline implemented at Sheffield Teaching Hospitals NHS Foundation Trust that recommends withholding antibiotics in patients with low serum procalcitonin (PCT), defined as ≤0.25 ng/mL. Results showed reduced antibiotic consumption in patients with PCT ≤0.25 ng/mL with no increase in mortality, alongside a reduction in subsequent carbapenem prescriptions during admission. The results support the effectiveness of this guideline, and further research is recommended to identify the optimal cut-off value for PCT in this setting.

Breath tests in Western Australia: Examining the economic dividends and effectiveness of general deterrence

In this paper, we examine the relationship between traffic enforcement (in the form of roadside breath testing for alcohol) and traffic outcomes (alcohol-related traffic crashes) to identify an optimal point of traffic enforcement. In Western Australia (WA), Police are authorised to stop any driver and measure their blood alcohol concentration via a sample of their breath. Using a metric employed by Ferris et al. (2013) and a methodology analogous to that utilised by Cameron (2013), we model the relationship between alcohol related traffic crashes and the saturation of breath testing in WA from January 2008 to April 2018. Our analysis suggests that given the saturation of breath testing in 2018 (1.2 tests per licenced driver), a 10 % increase in breath testing would be associated with a decline of 0.34 alcohol related traffic crashes (ARTC) per 100,000 drivers per month, equating to six fewer crashes per month, state-wide. In addition, using 'willingness to pay' and human capital cost metrics to approximate the social costs of ARTC, we employ a cost-benefit analysis to estimate the point at which the social costs of ARTC equal the economic costs of breath tests. Our analysis suggests that an increase in the number of tests to 143 % of all licensed WA drivers (an increase of 450,000 breath tests from the 2017/18 financial year) would be anticipated to save the state AUD$13.3 million annually in the human capital costs of ARTC. Our findings suggest that a further increase in breath tests to 154% of all licensed WA drivers (an increase of 650,000 breath tests from 2017/18) may save the state AUD$31.0 million annually in willingness to pay costs. The analytics below present a novel combination of methods to approximate the relative economic merits of increases in traffic enforcement. Furthermore, the findings outlined here have practical applications for operational policing, while providing an analytical perspective for policy makers faced with making recommendations regarding the volume and saturation of breath tests.

Technical nuances to minimize common complications of deep brain stimulation

The implantation of deep brain stimulator electrodes is associated with infrequent complications. These complications are consistent across prospective trials and include infection, skin erosion, hemorrhage, and lead misplacement. Nuances of surgical technique can be used to minimize the risk of these commonly noted complications. Several of these technical nuances are highlighted in this video submission. The video can be found here: https://youtu.be/GL09W9p013g .

Non ictal onset zone: A window to ictal dynamics

The focal and network concepts of epilepsy present different aspects of electroclinical phenomenon of seizures. Here, we present a 23-year-old man undergoing surgical evaluation with left fronto-temporal electrocorticography (ECoG) and microelectrode-array (MEA) in the middle temporal gyrus (MTG). We compare action-potential (AP) and local field potentials (LFP) recorded from MEA with ECoG. Seizure onset in the mesial-temporal lobe was characterized by changes in the pattern of AP-firing without clear changes in LFP or ECoG in MTG. This suggests simultaneous analysis of neuronal activity in differing spatial scales and frequency ranges provide complementary insights into how focal and network neurophysiological activity contribute to ictal activity.

Seeing is believing: neural representations of visual stimuli in human auditory cortex correlate with illusory auditory perceptions

In interpersonal communication, the listener can often see as well as hear the speaker. Visual stimuli can subtly change a listener's auditory perception, as in the McGurk illusion, in which perception of a phoneme's auditory identity is changed by a concurrent video of a mouth articulating a different phoneme. Studies have yet to link visual influences on the neural representation of language with subjective language perception. Here we show that vision influences the electrophysiological representation of phonemes in human auditory cortex prior to the presentation of the auditory stimulus. We used the McGurk effect to dissociate the subjective perception of phonemes from the auditory stimuli. With this paradigm we demonstrate that neural representations in auditory cortex are more closely correlated with the visual stimuli of mouth articulation, which drive the illusory subjective auditory perception, than the actual auditory stimuli. Additionally, information about visual and auditory stimuli transfer in the caudal-rostral direction along the superior temporal gyrus during phoneme perception as would be expected of visual information flowing from the occipital cortex into the ventral auditory processing stream. These results show that visual stimuli influence the neural representation in auditory cortex early in sensory processing and may override the subjective auditory perceptions normally generated by auditory stimuli. These findings depict a marked influence of vision on the neural processing of audition in tertiary auditory cortex and suggest a mechanistic underpinning for the McGurk effect.

Decoding stimulus identity from multi-unit activity and local field potentials along the ventral auditory stream in the awake primate: implications for cortical neural prostheses

OBJECTIVE

Hierarchical processing of auditory sensory information is believed to occur in two streams: a ventral stream responsible for stimulus identity and a dorsal stream responsible for processing spatial elements of a stimulus. The objective of the current study is to examine neural coding in this processing stream in the context of understanding the possibility for an auditory cortical neural prosthesis.

APPROACH

We examined the selectivity for species-specific primate vocalizations in the ventral auditory processing stream by applying a statistical classifier to neural data recorded from microelectrode arrays. Multi-unit activity (MUA) and local field potential (LFP) data recorded simultaneously from primary auditory complex (AI) and rostral parabelt (PBr) were decoded on a trial-by-trial basis.

MAIN RESULTS

While decode performance in AI was well above chance, mean performance in PBr did not deviate >15% from chance level. Mean performance levels were similar for MUA and LFP decodes. Increasing the spectral and temporal resolution improved decode performance; while inter-electrode spacing could be as large as 1.14 mm without degrading decode performance.

SIGNIFICANCE

These results serve as preliminary guidance for a human auditory cortical neural prosthesis; instructing interface implementation, microstimulation patterns and anatomical placement.

Detection and classification of multiple finger movements using a chronically implanted Utah Electrode Array

The ability to detect and classify individual and combined finger movements from neural data is rapidly advancing. The work that has been done has demonstrated the feasibility of decoding finger movements from acutely recorded neurons. There is a need for a recording model that meets the chronic requirements of a neuroprosthetic application and to address this need we have developed an algorithm that can detect and classify individual and combined finger movements using neuronal data acquired from a chronically implanted Utah Electrode Array (UEA). The algorithm utilized the firing rates of individual neurons and performed with an average sensitivity and an average specificity that were both greater than 92% across all movement types. These results lend further support that a chronically implanted UEA is suitable for acquiring and decoding neuronal data and also demonstrate a decoding method that can detect and classify finger movements without any a priori knowledge of the data, task, or behavior.

Platinum microwire for subdural electrocorticography over human neocortex: millimeter-scale spatiotemporal dynamics

Platinum microwires, terminated at regular intervals to form a grid of contacts, were used to record electric potentials at the surface of the cerebral cortex in human subjects. The microwire grids were manufactured commercially with 75 μm platinum wire and 1 mm grid spacing, and are FDA approved. Because of their small size and spacing, these grids could be used to explore the scale of spatiotemporal dynamics in cortical surface potentials. Electrochemical impedance spectroscopy was used to characterize their recording properties and develop a frequency-dependent electrical model of the micro-electrodes. Data recorded from multiple sites in human cortex were analyzed to explore the relationship between linear correlation and separation distance. A model was developed to explore the impact of cerebrospinal fluid on signal spread among electrodes. Spatial variation in the per-electrode performance decoding articulated speech from face-motor and Wernicke's areas of cortex was explored to understand the scale of information processing at the cortex. We conclude that there are important dynamics at the millimeter scale in human subdural electrocorticography which may be important in maximizing the performance of neural prosthetic applications.

Decoding spoken words using local field potentials recorded from the cortical surface

Pathological conditions such as amyotrophic lateral sclerosis or damage to the brainstem can leave patients severely paralyzed but fully aware, in a condition known as 'locked-in syndrome'. Communication in this state is often reduced to selecting individual letters or words by arduous residual movements. More intuitive and rapid communication may be restored by directly interfacing with language areas of the cerebral cortex. We used a grid of closely spaced, nonpenetrating micro-electrodes to record local field potentials (LFPs) from the surface of face motor cortex and Wernicke's area. From these LFPs we were successful in classifying a small set of words on a trial-by-trial basis at levels well above chance. We found that the pattern of electrodes with the highest accuracy changed for each word, which supports the idea that closely spaced micro-electrodes are capable of capturing neural signals from independent neural processing assemblies. These results further support using cortical surface potentials (electrocorticography) in brain-computer interfaces. These results also show that LFPs recorded from the cortical surface (micro-electrocorticography) of language areas can be used to classify speech-related cortical rhythms and potentially restore communication to locked-in patients.

Multi-scale recordings for neuroprosthetic control of finger movements

We trained a rhesus monkey to perform individuated and combined finger flexions and extensions of the thumb, index, and middle finger. A Utah Electrode Array (UEA) was implanted into the hand region of the motor cortex contralateral to the monkey's trained hand. We also implanted a microwire electrocorticography grid (microECoG) epidurally so that it covered the UEA. The microECoG grid spanned the arm and hand regions of both the primary motor and somatosensory cortices. Previously this monkey had Implantable MyoElectric Sensors (IMES) surgically implanted into the finger muscles of the monkey's forearm. Action potentials (APs), local field potentials (LFPs), and microECoG signals were recorded from wired head-stage connectors for the UEA and microECoG grids, while EMG was recorded wirelessly. The monkey performed a finger flexion/extension task while neural and EMG data were acquired. We wrote an algorithm that uses the spike data from the UEA to perform a real-time decode of the monkey's finger movements. Also, analyses of the LFP and microECoG data indicate that these data show trial-averaged differences between different finger movements, indicating the data are potentially decodeable.

Classification of spoken words using surface local field potentials

Cortical surface potentials recorded by electrocorticography (ECoG) have enabled robust motor classification algorithms in large part because of the close proximity of the electrodes to the cortical surface. However, standard clinical ECoG electrodes are large in both diameter and spacing relative to the underlying cortical column architecture in which groups of neurons process similar types of stimuli. The potential for surface micro-electrodes closely spaced together to provide even higher fidelity in recording surface field potentials has been a topic of recent interest in the neural prosthetic community. This study describes the classification of spoken words from surface local field potentials (LFPs) recorded using grids of subdural, nonpenetrating high impedance micro-electrodes. Data recorded from these micro-ECoG electrodes supported accurate and rapid classification. Furthermore, electrodes spaced millimeters apart demonstrated varying classification characteristics, suggesting that cortical surface LFPs may be recorded with high temporal and spatial resolution to enable even more robust algorithms for motor classification.

Toward the development of a cortically based visual neuroprosthesis

Motivated by the success of cochlear implants for deaf patients, we are now facing the goal of creating a visual neuroprosthesis designed to interface with the occipital cortex as a means through which a limited but useful sense of vision could be restored in profoundly blind patients. We review the most important challenges regarding this neuroprosthetic approach and emphasize the need for basic human psychophysical research on the best way of presenting complex stimulating patterns through multiple microelectrodes. Continued research will hopefully lead to the development of and design specifications for the first generation of a cortically based visual prosthesis system.

A minimally invasive approach to long-term head fixation in behaving nonhuman primates

We have designed a device for long-term head fixation for use in behaving nonhuman primates that is robust yet minimally invasive and simple to use. This device is a modified version of the halo system that is used in humans for cervical traction and stabilization after spinal column injuries. This device consists of an aluminum halo with four titanium skull pins offset from the halo by aluminum posts. The titanium pins insert onto small segments of cranially reinforcing titanium plate, which are attached to the skull with titanium cortex screws. The surgery involves four scalp incisions, placement of the reinforcing plates, insertion of the pins for attachment of the halo, and incision closure. After the halo is attached, the animal's head can be fixed to a primate chair using a custom-built attachment arm that provides three degrees of adjustability for proper positioning during behavioral tasks. We have installed this device on two Macaque monkeys weighing 7 and 10kg. The halos have been in place on these animals for up to 8 months without signs of discomfort or loss of fixation. Using this method of head fixation, we have been able to track the animals' eye positions with an accuracy of less than two visual degrees while they perform behavioral tasks.

EEG infraslow activity in absence and partial seizures

It is currently assumed that for recording of infraslow activity (ISA) DC-coupled amplifiers are required. This report will demonstrate that this may not be the case and presents some data about its potential clinical usefulness. Archived EEGs of 29 seizures from 6 children with absence attacks, accompanied by 3 Hz classical spike-wave discharges (SW), were compared with 20 partial seizures from 10 adult patients. The data from the children were acquired on a Bio-logic system, those from the adults on a Grass-Telefactor instrument. In the children the original 30-minute routine EEG was used while in the adults stored videomonitored data were excerpted to provide 20-minute segments which included the preictal, ictal and postictal state. All data were analyzed with the BESA software package. The seizures were evaluated separately on conventional filter settings, full band of 0.01-to the upper limit of the instrument, and 0.01-0.1 Hz (infraslow activity, ISA). Filter settings of 0.01-0.1 Hz provided a better assessment of ISA than when the full band was evaluated. Absence seizures showed bilateral essentially synchronous ISA with a negative positive sequence in the frontal areas and opposite polarity in the posterior head regions. In partial seizures when seizure onset was clearly lateralizeable from conventional frequency settings ISA corresponded to that hemisphere, but the electrode position could be displaced to a neighboring one from the one which was maximally involved on conventional settings. Topographic analysis showed two types of ISA: one with focal spread only and the other where there was in addition an element of synchrony especially in the frontal areas. It is concluded that ISA can be recovered from conventional EEG recordings and may be helpful not only in determining the area(s) of seizure onset but can also differentiate truly focal seizures from those where an additional generalized seizure tendency is present. This is likely to be important when epilepsy surgery is performed in absence of a demonstrable structural lesion.

Randomized trial to improve fracture prevention in nursing home residents

BACKGROUND

Interventions to improve the fracture prevention in nursing homes are needed.

METHODS

Cluster-randomized, single-blind, controlled trial of a multi-modal quality improvement intervention. Nursing homes (n=67) with > or =10 residents with a diagnosis of osteoporosis or recent hip fracture (n=606) were randomized to receive an early or delayed intervention consisting of audit and feedback, educational modules, teleconferences, and academic detailing. Medical record abstraction and the Minimum Data Set were used to measure the prescription of osteoporosis therapies before and after the intervention period. Analysis was at the facility-level and Generalized Estimating Equation modeling was used to account for clustering.

RESULTS

No significant improvements were observed in any of the quality indicators. The use of osteoporosis pharmacotherapy or hip protectors improved by 8.0% in the intervention group and 0.6% in the control group, but the difference was not statistically significant (P=.72). Participation in the intervention activities was low, but completion of the educational module (odds ratio [OR] 4.8, 95% confidence interval [CI], 1.9-12.0) and direct physician contact by an academic detailer (OR 4.5, 95% CI, 1.1-18.2) were significantly associated with prescription of osteoporosis pharmacotherapy or hip protectors in multivariable models.

CONCLUSIONS

Audit-feedback and education interventions were ineffective in improving fracture prevention in the nursing home setting, although results may have been tempered by low participation in the intervention activities.

Prevalence and predictors of osteoporosis treatment in nursing home residents with known osteoporosis or recent fracture

SUMMARY

We studied nursing home residents with osteoporosis or recent fracture to determine the frequency and predictors of osteoporosis treatment. There was wide variation in performance, and both clinical and systems variables predicted use. This study shows that improvement in osteoporosis care is possible and important for many nursing homes.

INTRODUCTION

We determined the prevalence and predictors of osteoporosis evaluation and treatment in high-risk nursing home residents.

METHODS

We identified 67 nursing facilities in North Carolina and Arizona with > 10 residents with osteoporosis or recent hip fracture. Medical records (n=895) were abstracted for osteoporosis evaluation [dual-energy X-ray absorptiometry (DXA), vitamin D level, serum calcium), treatment (calcium, vitamin D, osteoporosis medication, hip protectors), clinical, and systems covariates. Data were analyzed at the facility level using mixed models to account for the complex nesting of residents within providers and nursing facilities.

RESULTS

Calcium and vitamin D was prescribed for 69% of residents, bisphosphonates for 19%, calcitonin for 14%, other pharmacologic therapies for 6%, and hip protectors for 2%. Overall, 36% received any bone protection (medication or hip protectors), with wide variation among facilities (0-85%). Factors significantly associated with any bone protection included female gender [odds ratio (OR) 2.4, (1.5-3.7)] and nonurban/suburban location [1.5, (1.1-2.2)]. Residents with esophagitis, peptic ulcer disease (PUD), or dysphagia [0.6, (0.4-0.9)] and alcohol abuse [0.2, (0.0-0.9)] were less likely to receive treatment.

CONCLUSIONS

There is substantial variation in the quality of osteoporosis treatment across nursing homes. Interventions that improve osteoporosis quality of care are needed.

Endocervical sampling: a comparison of endocervical brush, endocervical curette, and combined brush with curette techniques

OBJECTIVE

This study was conducted to compare the collection of endocervical specimens by endocervical brush, curette, and a combined curette and brush technique.

METHODS

Women underwent colposcopy with endocervical curettage using one of 3 collection methods.

RESULTS

The endocervical brush produced equivalent amounts of tissue and endocervical cells compared to the curette alone or combined techniques. More squamous and glandular atypia and SIL/AIS were found when a brush was used, but a statistically significant difference was not noted. The brush alone produced a significantly greater percentage of samples that were insufficient for diagnosis and more specimens without stromal components. The brush with the curette as a combined technique provided no improvement in amounts of tissue, endocervical cells/clusters, or amount of stroma retrieved.

CONCLUSION

Each technique has advantages and disadvantages in terms of what types of components are collected and what diagnosis may be determined from the sample taken.

Giant tumefactive perivascular spaces

BACKGROUND AND PURPOSE

The brain perivascular spaces (PVSs) are pial-lined, interstitial fluid-filled structures that accompany penetrating arteries. When enlarged, they may cause mass effect and can be mistaken for more ominous pathologic processes. The purpose of this study was to delineate the broad clinical and imaging spectrum of this unusual condition.

METHODS

Thirty-seven cases of giant PVSs were identified from 1988 to 2004 and were retrospectively reviewed. Clinical data collected included patient demographics, presenting symptoms, and follow-up. Histopathologic data were reviewed when available. Images were evaluated for size and location of the giant PVSs, associated mass effect, hydrocephalus, adjacent white matter changes, and contrast enhancement.

RESULTS

There were 24 men and 13 women with an age range of 6-86 years, (mean 46 years). The most common presenting feature was headache (15 patients). Thirty-two cases had multilocular clusters of variably sized cysts. Five lesions were unilocular. All lesions had signal intensity comparable to CSF and did not enhance. The most common location for the giant PVSs was the mesencephalothalamic region (21/36). Fourteen were located in the cerebral white matter; two were in the dentate nuclei. Nine giant mesencephalothalamic PVSs had associated hydrocephalus, which required surgical intervention.

CONCLUSION

Giant tumefactive PVSs most often appear as clusters of variably sized cysts that are isointense relative to CSF and do not enhance. They are most common in the mesencephalothalamic region and may cause hydrocephalus. Although they may have striking mass effect, giant PVSs should not be mistaken for neoplasm or other diseases.

Surgical considerations regarding giant dilations of the perivascular spaces

Object. Dilations of brain perivascular spaces (PVSs), also known as Virchow—Robin spaces, are routinely identified on magnetic resonance imaging studies of the brain and recognized as benign normal variants. Giant dilations occur only rarely and can be easily misdiagnosed as central nervous system tumors. The relevant surgical literature was reviewed to help establish indications for surgical intervention in these typically benign lesions.

Methods. Giant dilations of the PVSs in 12 patients who had undergone surgery for several different indications were identified. Both clinical and radiographic presentations of these patients were reviewed along with the surgical procedures.

Conclusions. Dilations of the PVSs can become giant lesions that may necessitate surgical intervention to relieve mass effect or hydrocephalus. The relationship of these lesions to neurological symptoms such as tremor and seizures remains unclear.

Endolymphatic sac tumors in patients with and without von Hippel-Lindau disease: the role of genetic mutation, von Hippel-Lindau protein, and hypoxia inducible factor-1alpha expression

OBJECT

Endolymphatic sac (ELS) tumors are low-grade malignancies of the temporal bone that are associated with von Hippel-Lindau (VHL) disease but can also occur sporadically. The VHL gene product VHL protein is important in the regulation of hypoxia inducible factor (HIF)-1alpha, which controls expression of molecules that are important in angiogenesis and cell metabolism. In this study the authors examine the role of VHL and HIF-1 in ELS tumors.

METHODS

The ELS tumors from three patients were examined using the following method: DNA from tumor tissue was isolated, amplified by polymerase chain reaction and the VHL gene sequence was compared with the known wild-type sequence. Loss of heterozygosity (LOH) studies were performed to confirm the sequencing data. Immunohistochemical evaluation for VHL, HIF-1alpha, vascular endothelial growth factor (VEGF), and carbonic anhydrase IX (CA IX) was performed. Snap-frozen tumor tissue was examined using Western blot and HIF-1 immunoassays for HIF-1alpha and VHL expression. Two patients had sporadic ELS tumors and the other one suffered from VHL disease. Results of VHL gene sequencing were normal in the tissue derived from the sporadic ELS tumors. The ELS tumor, pheochromocytoma, and spinal hemangioblastoma were heterozygous for the same C-to-A transversion found in the germline carried by the patient with VHL disease. No LOH was detected in the tumor tissue obtained in the patient with VHL disease. Expression of HIF-1alpha, VEGF, and CA IX evaluated using immunohistochemical studies was elevated in the VHL-associated tumors. Nevertheless, Western blots and immunoassays for HIF-1alpha did not show elevated expression in these tumors.

CONCLUSIONS

The sporadic and VHL disease-associated ELS tumors in this study had normal VHL-mediated HIF-1 regulation. This is a result of normal VHL gene expression in the case of the sporadic ELS tumor. In the VHL-associated ELS tumor, this is due to one normal copy of the VHL gene and adequate VHL gene expression.

Seeding of a cavernous angioma with Mycoplasma hominis: case report

OBJECTIVE AND IMPORTANCE

To describe a unique case of hematogenous seeding of a cavernous angioma with the commensal organism Mycoplasma hominis.

CLINICAL PRESENTATION

A 40-year-old female patient presented with a severe headache and acute left facial nerve palsy. Imaging studies revealed a right frontal mass lesion with characteristics of a cavernous angioma.

INTERVENTION

The patient underwent a craniotomy for cavernous angioma resection. Purulent material was noted at the time of resection, and no hemorrhage was observed. Despite antibiotic therapy, the patient required repeat craniotomies for subsequent abscess treatment. M. hominis was identified as the pathogen.

CONCLUSION

M. hominis is a rare cause of brain abscesses and can be difficult to eradicate. Cavernous angiomas can be seeded hematogenously.

Proliferation of lens epithelial cells on the Acrysof intraocular lens: clinical and histological features of a case

Postoperative deposits on the surface of intraocular lenses (IOLs) have been demonstrated in vivo for many IOL material types. The Acrysof acrylic lens develops a granular material extending from the capsulorhexis margin onto the IOL's anterior surface during the first 4 weeks after surgery in a significant proportion of cases. Complete resolution of this membrane occurs by 3 months in almost all cases. The case is presented of an 81-year-old woman who had a persisting membrane coverng the IOL surface at 6 months. This membrane was removed surgically and pathology showed the constituent cells to be of lens epithelial cell origin.

The use of community surveys for health planning: the experience of 56 northwest rural communities

A rural health services development program of the University of Washington School of Medicine has worked for 15 years with communities throughout the five-state region of Alaska, Idaho, Montana, Washington and Wyoming to strengthen their health systems. In the course of that work, 56 communities were surveyed about their utilization and opinions of local health systems. This database allows the following generalizations to be made about rural Northwest communities: (1) People think highly of their local hospitals, physicians and other key components of the acute medical care system and want their hospitals to remain open. Older respondents are more satisfied than younger respondents; (2) the typical hospital market share is 36 percent, the typical physician market share is 50 percent (3) satisfaction with discrete, well-funded services such as pharmacy, ambulance and dentistry is quite high, whereas satisfaction with mental health and substance abuse treatment is significantly lower; (4) the most commonly cited serious problems in surveyed communities were "too few physicians or- services" and "care is too expensive"; and (5) there is great variation between communities in both satisfaction and utilization.

Long-term topical timolol and blood lipids: the Blue Mountains Eye Study

OBJECTIVES

To examine whether an association exists between long-term use of topical timolol and blood lipids, including high-density lipoprotein cholesterol (HDL-C), cholesterol, and triglycerides, among participants of the Blue Mountains Eye Study.

METHODS

From 1992 through 1994, a detailed medical and eye examination was performed in 3,654 people aged 49 years or older, representing 82% of permanent residents in two postcode areas west of Sydney. Glaucoma and ocular hypertension were diagnosed, and an ophthalmic history was taken, including use of topical timolol. Fasting blood tests were performed in 89% of subjects. Lipid levels were compared in subjects using topical timolol for at least 1 year with those not using timolol, after excluding people using oral beta-blockers, topical beta1-selective agents, or oral lipid-lowering medications.

RESULTS

Analyses compared blood lipids of 63 people who had used topical timolol for at least 1 year with 2,597 nonusers. No statistically significant differences were found in any blood lipid mean levels between treated and untreated people, after multivariate adjustment. However, subgroup analyses of men and women separately showed that male timolol users had a mean value of HDL-C 0.13 mmol/L (11%) lower then the mean value of male nonusers, while female timolol users had a mean value of HDL-C 0.09 mmol/L (5%) higher than the mean for female nonusers. There were no statistically significant associations between timolol treatment duration and HDL-C or other lipid levels. Previously reported adverse effects of oral beta-blockers on blood lipid levels were confirmed.

CONCLUSIONS

These population-based data suggest that long-term administration of topical timolol for glaucoma or ocular hypertension can cause adverse effects on HDL-C in men, but not in women. The magnitude of the effect in men was similar to that previously described in a number of short-term studies.

Comparison of optic disc image assessment methods when examining serial photographs for glaucomatous progression

AIM

To assess serial, simultaneous stereo optic disc images by four methods for glaucomatous progression.

METHODS

Using varying techniques, two ophthalmologists assessed serial optic disc images of 52 eyes from 27 patients with a mean duration between images of 18 months. The neuroretinal rim width was qualitatively assessed by four assessment methods and compared with quantitative rim measurements made using PC based software.

RESULTS

The highest sensitivity of 83% was achieved using computerised stereo chronoscopy.

CONCLUSION

Stereo chronoscopy improved the detection of subtle optic disc changes when compared with simpler assessment techniques.

Postoperative deposits on the Acrysof intraocular lens

PURPOSE

To report a commonly occurring change on the anterior surface of the Acrysof intraocular lens which is presumed to be due to the proliferation of lens epithelial cells from the capsulo-rhexis margin.

METHOD

Forty-one consecutive cases (31 patients) of Acrysof intraocular lens implantation were followed prospectively. Clinical charts were reviewed for changes on or within the lens and visual acuity and refractive changes recorded. All cases were dilated at 3-5 weeks postoperatively to facilitate observation of changes. Representative slit lamp photos were taken.

RESULTS

Deposits on the intraocular lens surface were noted on 18 of 41 lenses at 3-5 weeks post surgery. Deposits were not found on examinations conducted during the first postoperative week. All changes had fully resolved by 3 months.

CONCLUSIONS

The changes recorded had no impact on visual acuity. The deposits noted do not represent clinically important pathology. They may be an unusual marker of biocompatibility with this lens. Surgeons using this lens should be aware of these changes.

Developing laser-induced glaucoma in rabbits

PURPOSE

An animal mode of glaucoma is necessary for the study of its pathogenesis and treatment. The purpose of this study was to create open-angle glaucoma using a laser in rabbits.

METHODS

The trabecular meshwork of anaesthetized, adult, pigmented and albino rabbits was ablated internally using a diode laser via a gonioscopy lens, or externally through the limbus. In albino rabbits we used Chinese ink to pigment the angle and methylcellulose to open the iridocorneal angle. The eyes were examined weekly and histological assessment was performed.

RESULTS

The success rate of intra-ocular hypertension was low (15%) and a result of synechial angle closure. A narrow angle prevented access of the laser beam to the trabecular meshwork and promoted damage to the ciliary processes located on the posterior iris.

CONCLUSIONS

Due to the unique anatomy of the rabbit eye, laser-induced glaucoma is difficult to achieve. To create a successful model it is necessary to widen the iridocorneal angle, selectively damage the trabecular meshwork and reduce inflammation.

Non-mydriatic fundus photography: a viable alternative to fundoscopy for identification of diabetic retinopathy in an Aboriginal population in rural Western Australia?

PURPOSE

To evaluate the Canon CR5-45NM non-mydriatic fundus camera (Canon, Kanagawa, Japan) for identifying retinopathy and the need for laser treatment in a population of Aboriginal patients with diabetes mellitus in rural Western Australia.

METHODS

Diabetic Aboriginal patients were photographed through undilated pupils using a Canon CR5-45NM non-mydriatic fundus camera, after which ophthalmoscopy was performed using indirect ophthalmoscopy through dilated pupils. The examining ophthalmologist recorded the presence of retinopathy and the need for laser treatment. A proportion of patients were rephotographed through dilated pupils. Photographs were reviewed by a second ophthalmologist who evaluated the quality of the image, the presence of retinopathy and the need for laser treatment. Results of fundus photographs and ophthalmoscopy were compared.

RESULTS

Three hundred and twenty-eight eyes in 164 Aboriginal patients were examined. The mean patient age was 48.2 years (range 16-81 years) and the mean duration of diabetes was 7.5 years (range 1-35 years). Seventy-four eyes (22.6%) were diagnosed with retinopathy using combined examination techniques, 44 (59.5%) of which were identified by ophthalmoscopy and 55 (74.3%) by photography. Thirty-five eyes were deemed to need treatment, 18 (51.4%) of which were identified by ophthalmoscopy and 30 (85.7%) by photography. Kappa coefficient measurement for agreement for presence of retinopathy and need for referral was 0.41 and 0.53, respectively. Photograph quality was significantly improved following pupil dilation.

CONCLUSIONS

The Canon CR5-45NM non-mydriatic fundus camera was relatively good at identifying diabetic retinopathy and could usefully be applied within a screening programme for treatable disease within this population.

Herbicide regulation: a case study of Michigan

Lawn-care herbicides are a type of pesticide regulated under federal and state pesticide legislation. The Michigan Department of Agriculture implements herbicide regulation to protect the public's health and welfare. Yet, due to gaps that exist in all levels of government in the regulation of lawn-care herbicide application, the public is placed at risk. The federal pesticide legislation (Federal Insecticide, Fungicide, and Rodenticide Act) provides for a lower standard of safety in the classification of herbicides applied in the residential context as opposed to the agricultural context. Michigan legislation (The Pesticide Control Act) exempts from the law persons applying general herbicides on their own premises. The state does not require public notification of risks or safety precautions prior to commercial application of these herbicides. Furthermore, on-site inspections are not performed for residential application of herbicides and the state applicator certification program is not assessed for effectiveness.

Vision testing in atrophic macular degeneration

PURPOSE

To determine the correlation between a group of vision tests in atrophic macular degeneration (AMD) in an office setting.

METHODS

Patients with documented vision loss from atrophic macular degeneration in one eye were invited to attend an eye clinic every three months for a series of six vision tests for their good eye followed by fundus photography. Modified contrast sensitivity, blue/yellow anomaloscopy, flicker fusion frequency, Amsler grid, and photostress recovery time were correlated with Snellen acuity using the Pearson correlation coefficient. The regression of the Snellen acuity on sex, age and the presence of disciform macular degeneration in the other eye was obtained using a general linear model.

RESULTS

The correlation with Snellen acuity result was low for all tests. It was highest for Amsler grid abnormality (r = -0.33345) and blue/yellow anomaloscopy matching range (r = -0.20742), where r denotes the correlation coefficient. Patient age was strongly correlated with Snellen results (P = 0.0001), but it was not significantly related to sex (P = 0.1187) or the presence of disciform macular degeneration in the other eye (P = 0.9989). The photostress recovery time showed enormous inter-visit variations and poor correlation with Snellen acuity (P = 0.0526).

CONCLUSIONS

The course of AMD is routinely assessed by Snellen acuity and any of several additional tests. When employing a test battery in an office setting, a clinician needs to know the relative utility and correlation between the tests at his disposal. Of the tests used in this study, the Amsler grid was the most useful addition to the Snellen acuity at all stages of atrophic macular degeneration, and blue/yellow anomaloscopy was useful only in mild macular degeneration where Snellen acuity was 6/12 or better.

Improving a rural hospital's peer review process

Quality monitoring in a small rural hospital is a challenge on many fronts. The case study presented here illustrates a quality monitoring failure and analyzes the contributing factors. Based on their experience, the authors suggest methods to improve small rural hospital quality monitoring.

Characteristics of the normal central visual field measured with resolution perimetry

The ring perimeter is an innovative device that measures the resolution threshold at 50 locations in the central visual field in approximately 6 min. This study was undertaken to define the characteristics of the resolution visual field in normal eyes using this instrument and to check the repeatability of the measurement. A total of 114 perimetrically naive, normal subjects aged from 20 to 79 years were prospectively enrolled; 55 randomly chosen subjects were tested twice, with a rest period of less than or equal to 60 s elapsing between examinations. The resolution threshold increased towards the periphery in all subjects. A small but significant decline in sensitivity occurred with age; this loss was greatest in the inner part of the field. Variability in threshold between subjects was not found to increase towards the periphery or in the upper field as compared with the lower. The field was highly repeatable when reexamined in the same subject. This study defines the resolution visual field in normal subjects, along with its inter- and intra-observer variability, and gives age-corrected predictive confidence intervals for each location of the field using the ring perimeter.

[Argon laser trabeculoplasty for open angle glaucoma--a four year follow-up]

79 patients (105 eyes) with uncontrolled open angle glaucoma underwent argon laser trabeculoplasty (ALT). The average pressure drop was 10.7 mmHg in 58 eyes at one year, 10.1 mmHg in 35 eyes at two years, 9.9 mm Hg in 48 eyes at three years and 10.2 mmHg in 24 eyes at four years. Teh mean success rate was 78%, failures occurred in the first six months in 21 of 23 eyes, the remaining eyes failed at three years, 18 eyes (17%) required filtering surgery. Average medication scores varied little from year 1 through year 4, 45 eyes (42.9%) were being treated with few medications after ALT. The results of ALT depend on the severity of glaucoma: the eyes with advanced disc damage (C/D greater than 0.9, visual field less than 20 degrees) had 59% rate of filtering surgery, while the eyes with C/D 0.6-0.8, visual field greater than 20 degrees at ALT had a filtering surgery rate of 3%.

Ocular abnormalities in deaf children: a discussion of deafness and retinal pigment changes

In a survey of 78 hearing impaired children, 33% were found to have ocular abnormalities. The abnormalities were relatively minor, the most frequent being altered retinal pigmentation. Although congenital rubella infection was the most common cause of this finding the cause in others was more obscure. Possible causes for hearing loss associated with retinal pigment and other tissue changes are abnormal cilia, abnormalities in cells with similar embryological origins and genetic defects affecting pigmentation.