Tablet-based electroencephalography diagnostics for patients with epilepsy in the West African Republic of Guinea.

BACKGROUND AND PURPOSE: Epilepsy is most common in lower-income settings where access to electroencephalography (EEG) is generally poor. A low-cost tablet-based EEG device may be valuable, but the quality and reproducibility of the EEG output are not established. METHODS: Tablet-based EEG was deployed in a heterogeneous epilepsy cohort in the Republic of Guinea (2018-2019), consisting of a tablet wirelessly connected to a 14-electrode cap. Participants underwent EEG twice (EEG1 and EEG2), separated by a variable time interval. Recordings were scored remotely by experts in clinical neurophysiology as to data quality and clinical utility. RESULTS: There were 149 participants (41% female; median age 17.9 years; 66.6% ≤21 years of age; mean seizures per month 5.7 ± SD 15.5). The mean duration of EEG1 was 53 ± 12.3 min and that of EEG2 was 29.6 ± 12.8 min. The mean quality scores of EEG1 and EEG2 were 6.4 [range, 1 (low) to 10 (high); both medians 7.0]. A total of 44 (29.5%) participants had epileptiform discharges (EDs) at EEG1 and 25 (16.8%) had EDs at EEG2. EDs were focal/multifocal (rather than generalized) in 70.1% of EEG1 and 72.5% of EEG2 interpretations. A total of 39 (26.2%) were recommended for neuroimaging after EEG1 and 22 (14.8%) after EEG2. Of participants without EDs at EEG1 (n = 53, 55.8%), seven (13.2%) had EDs at EEG2. Of participants with detectable EDs on EEG1 (n = 23, 24.2%), 12 (52.1%) did not have EDs at EEG2. CONCLUSIONS: Tablet-based EEG had a reproducible quality level on repeat testing and was useful for the detection of EDs. The incremental yield of a second EEG in this setting was ~13%. The need for neuroimaging access was evident.

Stereotactic cortical resection in non-lesional extra-temporal partial epilepsy.

The presentation and treatment of a patient with extra-temporal non-lesional partial epilepsy is discussed herein. His clinical semiology was consistent with supplementary motor area seizures; however, MR imaging did not demonstrate a lesion. A region of stable cortical glucose hypermetabolism in the left frontal region was noted with 2-fluoro-2-deoxy-D-glucose (FDG)-PET. This was consistent with the frequent interictal discharges evident over the left fronto-temporal region and the stereotypic high amplitude ictal discharges arising with highest amplitude from the left frontal region. Epileptiform activity evident on an intracranial 64-point subdural recording grid placed over the left dorsolateral frontal cortex confirmed a distribution concordant with FDG-PET findings. The subsequent resection was guided by the PET and EEG findings rather than structural MR imaging, and a limited cortical resection led to an immediate and substantial reduction in seizure frequency.

Double sequential external shocks for refractory ventricular fibrillation.

OBJECTIVES: A technique for terminating refractory ventricular fibrillation is described. BACKGROUND: Refractory ventricular fibrillation can occur in up to 0.1% of electrophysiologic studies. Animal studies have shown that rapid sequential shocks may reduce ventricular fibrillation threshold. METHODS: Five patients of 2,990 consecutive patients in a 3-year period experienced refractory ventricular fibrillation during 5,450 routine electrophysiologic studies. Multiple shocks were delivered by means of a single defibrillator. Double sequential shocks were delivered externally 0.5 to 4.5 s apart by means of two defibrillators with separate pairs of electrodes. RESULTS: In all patients, standard defibrillation was unsuccessful, but all were successfully resuscitated using the double sequential shocks. CONCLUSIONS: This report stresses the importance of an additional defibrillator being readily available during electrophysiologic testing. This technique of rapid, double sequential external shocks may have general applicability, providing a simple and potentially lifesaving approach to refractory ventricular fibrillation.

Fatal puerperal cerebral vasospasm and stroke in a young woman.

A woman who experienced postpartum cerebral infarction, brain edema, and death is described. Angiography implicated cerebral vasospasm as the primary etiology.

Age dependence of complete heart block complicating radiofrequency ablation of the atrioventricular nodal slow pathway.

A significant age dependence of the risk of complete heart block complicating radiofrequency ablation of the AV nodal slow pathway was noticed, with no patients <45 years of age experiencing this complication.

A new system for classification of cardiac death as arrhythmic, ischemic, or due to myocardial pump failure.

Existing classifications of cardiac death fail to incorporate current understanding of the pathophysiology of sudden cardiac death. We developed a new scheme for classifying cardiac death that defines 3 categories of underlying mechanism: primary arrhythmia, acute myocardial ischemia/infarction, and myocardial pump failure. Using this new system, we classified the mechanism of 106 definite cardiac deaths from the Recurrent Coronary Prevention Project. Fifty deaths (47%) were classified as arrhythmic, 46 (43%) as ischemic, and 9 (8%) as due to myocardial pump failure (1 death was not classifiable). All 36 witnessed arrhythmic deaths were sudden and 8 of 9 witnessed myocardial pump failure deaths were nonsudden. The 38 witnessed ischemic deaths were split evenly between sudden and nonsudden. Interrater agreement for the classification of mechanism was 100%. This classification scheme, if validated in subsequent studies, will provide a useful algorithm for classifying deaths by underlying mechanism.

Equine arch vessel anomaly associated with coarctation of the aorta.

Angiography in a 30-year-old man revealed the unique combination of aortic coarctation and an unusual arch anomaly. Proximal to the coarctation, a single arch vessel trifurcated into the brachiocephalic, left common carotid and left subclavian arteries. This anomalous arch vessel is a normal equine variant.

Boron neutron capture therapy of a murine mammary carcinoma using a lipophilic carboranyltetraphenylporphyrin.

The first control of a malignant tumor in vivo by porphyrin- mediated boron neutron capture therapy (BNCT) is described. In mice bearing implanted EMT-6 mammary carcinomas, boron uptake using a single injection of either p-boronophenylalanine (BPA) or mercaptoundecahydrododecaborane (BSH) was compared with either a single injection or multiple injections of the carboranylporphyrin CuTCPH. The BSH and BPA doses used were comparable to the highest doses of these compounds previously administered in a single injection to rodents. For BNCT, boron concentrations averaged 85 microg (10)B/g in the tumor and 4 microg (10)B/g in blood 2 days after the last of six injections (over 32 h) that delivered a total of 190 microg CuTCPH/g body weight. During a single 15, 20, 25 or 30 MW-min exposure to the thermalized neutron beam of the Brookhaven Medical Research Reactor, a tumor received average absorbed doses of approximately 39, 52, 66 or 79 Gy, respectively. A long-term (>200 days) tumor control rate of 71% was achieved at a dose of 66 Gy with minimal damage to the leg. Equivalent long-term tumor control by a single exposure to 42 Gy X rays was achieved, but with greater damage to the irradiated leg.

Expanding the guidelines for electronic communication with patients: application to a specific tool.

In 1998, the American Medical Informatics Association (AMIA) published a white paper entitled "Guidelines for the Clinical Use of Electronic Mail with Patients," which outlined a practical framework for this interaction. Interest in the use of other Internet-based tools, such as the World Wide Web, to enhance clinical communication is increasing. In such systems, static information can be made centrally available to patients and interactive tools such as messaging systems, schedules, and individualized care regimens can be integrated within the site. Site-specific guidelines are needed to address potential problems inherent in the particular services being offered. This article presents advice on developing site-specific guidelines, with examples, based on experience gained in developing and refining guidelines for the use of PatientWeb at the Massachusetts General Hospital Department of Neurology.

GABAergic neurons in rat hippocampal culture.

The experiments described here were designed to study biochemical and histological measures of gamma-aminobutyric acid (GABA) uptake and glutamic acid decarboxylase (GAD) in primary dissociated cell cultures prepared from 17-21-day fetal rat hippocampus. Preparations from all ages of animals, except 21-day fetuses, were enriched in GABAergic neurons, when compared to the adult hippocampus in situ. These cells comprise 30-50% of the large, phase-bright, process-bearing cells in hippocampal cultures as estimated by autoradiography of GABA uptake and GAD immunocytochemistry. Neurons concentrate GABA by a relatively slow but high-affinity process (Km = 2.6 microM) that has considerably higher maximum velocity than glial uptake (Vmax = 479 pmol/mg protein/min for neurons and 31 pmol/mg protein/min for glia). No low-affinity uptake process was noted in neurons or glia. GABA uptake into neurons was competitively inhibited by cis-4-OH-nipecotic acid (Ki = 39 +/- 11 microM). These cultures also possess considerable GAD activity, up to 6 nmol/mg protein/min in one-month-old cultures, which approximates that of the adult hippocampus. Both GABA uptake and GAD activity increased with time in culture. The enrichment of GABAergic markers indicates that this preparation may be useful for the detailed study of hippocampal GABAergic neurons.

Factors affecting the phosphorylation of a 41,000 dalton protein of hippocampal subcellular fractions.

The phosphorylation of the alpha-subunit of mitochondrial pyruvate dehydrogenase may be involved in the development of long-term potentiation in the hippocampus. Study of this hypothesis is hampered by variability in the incorporation of 32P into pyruvate dehydrogenase of hippocampal subcellular preparations, in vitro. 32P from [gamma-32P]ATP was incorporated into pyruvate dehydrogenase present in mitochondria and in a membrane-enriched synaptic particulate fraction from hippocampus. However, the presence of the synaptic fraction decreased isotopic labeling of the mitochondrial protein. This effect was not due to inhibition of the protein kinase or activation of a protein phosphatase, but the rate of ATP hydrolysis was found to be higher in the synaptic fraction than in the mitochondria (34 nmol/mg protein/min vs 14 nmol/mg protein/min). These data raise a variety of questions about the interpretation of the in vitro phosphorylation assay. It is concluded that variability in in vitro labeling can be minimized if the effect of ATP hydrolysis is diminished by use of a higher concentration of ATP. In addition, these data indicate that quantitative comparisons of the in vitro phosphorylation of diverse subcellular preparations must take into account differential rates of ATP hydrolysis.

Long-term potentiation in the hippocampal slice: possible involvement of pyruvate dehydrogenase.

Tetanic stimulation of fibers in the hippocampal slice preparation produces long-term potentiation (LTP) and also decreases the in vitro incorporation of phosphate into the alpha subunit of pyruvate dehydrogenase (alpha PDH). This paper describes 6 experiments that were undertaken to replicate this observation. Hippocampal slices were incubated in a specially designed chamber and stimulated with a tungsten wire electrode in the stratum radiatum for 1 s at 100 Hz. Two minutes after the tetanus, the stimulated slices were removed alternately with control (not tetanized) slices and each group was pooled for subcellular fractionation and labeling of the fractions with [32P]ATP. Proteins were separated by electrophoresis and relative 32P contents of 41K and 50K protein bands were studied. Tetanic stimulation of the stratum radiatum did not affect subsequent phosphorylation of a 50K Mr protein that has been reported to be altered by perforant path activation. Stimulation also had no effect on pyruvate dehydrogenase enzyme activity or on the ratio of active (dephosphorylated) to inactive enzyme. In most cases tetanic stimulation produced no significant change in the in vitro phosphorylation of this enzyme. Only under one set of conditions, labeling with 250 microM [gamma-32P]ATP for 10 s, was a decrease in the in vitro labeling of alpha PDH shown to be statistically significant. These findings suggest that LTP is not necessarily accompanied by an initial change in PDH phosphorylation level or activity but may be associated with a decrease in the kinase activity directed toward this protein.

Early changes in material properties of rabbit articular cartilage after meniscectomy.

We have correlated early material and biochemical changes in articular cartilage in a surgical model for cartilage degeneration. Medial meniscectomy was performed on the left knee of 17 adult, female New Zealand white rabbits. The equilibrium Young's modulus of cartilage was assessed by an indentation test in situ at defined sites on the medial and lateral tibial plateaus of the operated and control knees; the cartilage was then excised and analyzed biochemically. Focal changes were consistently observed in the medial surface of the operated knee. The equilibrium modulus and the glycosaminoglycan content fell rapidly, reaching a minimum by 2 weeks after surgery; the lateral tibial surface was essentially unaffected. Six months after surgery, the glycosaminoglycan content had returned to normal and the modulus to near normal. Independent measurements on cored plugs from the medial surface 2 weeks after surgery revealed a significant decrease in both the dynamic stiffness and the streaming potential in the operated knee compared with the control. The findings suggest that normal ambulatory loads in vivo will deform the affected medial cartilage much more than normal. It remains to be seen if altered mechanical stresses are solely responsible for initiating and sustaining matrix remodeling by the chondrocytes.

14C-dopamine microinjected into the brain-stem of the rat: dispersion kinetics, site content and functional dose.

A morphological analysis was undertaken of both the dispersion characteristics and tissue content of dopamine (DA) microinjected acutely into the brain-stem of the anesthetized rat. 14C-DA, with a specific activity of 56-62 mCi/mMol, was infused unilaterally into the pars compacta of the substantia nigra in one of four test volumes: 0.5, 1.0, 4.0 or 8.0 microliters. The concentration of the 14C-DA solution was 1.0 microCi/microliter, equivalent to 3.01 micrograms/microliters, which was delivered at an injection rate of 1.0 microliter per 45 sec. At an interval of either one min or 15 min following the microinjection, the rat's brain was removed rapidly from its calvarium, flash frozen and then cut in the coronal plane on a freezing microtome in 500 micron slabs. After each of the respective serial slabs was mounted on glass, the Eik Nes-Brizzee trochar technique for the discrete removal of tissue samples was used to obtain 0.5 mm dia. cylindrical plugs of meso-diencephalic tissue at distances from the site of injection ranging from 0.5 to 2.5 mm, center to center. Each sample plug was subsequently solubilized and 14C-DA activity quantitated by liquid scintillation spectrometry. The results show that regardless of volume, the spatial patterning of the microinjected solution assumes a tear-drop or pear shape, not a sphere. Further, as the volume of the injection is increased from 0.5 to 8.0 microliters, the magnitude of the dispersion of 14C-DA is enhanced throughout the surrounding parenchyma, but not in a linear fashion.(ABSTRACT TRUNCATED AT 250 WORDS)

Monitoring carotid test occlusions with continuous EEG and clinical examination.

We routinely monitor invasive neuroradiologic carotid balloon test occlusions with continuous polygraph and quantitative EEG along with repeated detailed clinical examinations. Four of 17 consecutive cases showed changes during carotid occlusion. In one instance, an immediate delta increase was accompanied by slurred speech and aphasia. Another showed alpha attenuation without clinical change. A third patient had significant clinical change without EEG change. Nine of the 17 cases underwent permanent therapeutic carotid occlusion as treatment of an intracerebral vascular abnormality. Seven of these nine had no EEG or clinical changes during monitoring and have had no functional abnormalities on follow-up. The patient with focal alpha attenuation had an accidental balloon detachment but has had no functional or structural neurologic abnormalities. The patient with minor regional increased delta received a permanent carotid occlusion and went on to develop clinical signs 24 h later. We believe that continuous EEG monitoring and repeated clinical examinations provide useful ways of evaluating cerebral circulation during carotid test occlusions.

Periodic lateralized epileptiform discharges--a critical review.

It is the purpose of this review to critically consider and organize the literature dealing with the ephemeral electroencephalographic (EEG) pattern periodic lateralized epileptiform discharges (PLEDs). Although the retrospective nature of these studies limits their ability to discuss accurately the clinical and pathophysiological aspects of this EEG entity, the available data strongly emphasize stroke as the dominant etiology and its high association with seizures. Recent evidence, particularly from functional neuroimaging studies, strongly suggests that PLEDs might reflect a key pattern for focal hyperexcitability in the penumbra zone of ischemic stroke. The authors prefer to consider PLEDs as an EEG signature of a dynamic pathophysiological state in which unstable neurobiological processes create an ictal-interictal continuum, with the nature of the underlying neuronal injury, the patient's preexisting propensity to have seizures, and the co-existence of any acute metabolic derangements all contributing to whether seizures occur or not. This review underlines the need for further sophisticated prospective controlled studies implementing early continuous EEG monitoring in order to contribute to an understanding of the incidence, dynamics, and relevance of this pattern.

Tachycardias of right ventricular origin.

Ventricular tachycardia arising from the right ventricle usually has a left bundle branch morphology and occurs in a variety of disorders. Uhl's anomaly and right ventricular dysplasia may represent a spectrum of one disorder and are a cause of right heart dilatation, failure, and premature sudden death due to ventricular arrhythmias. Familial forms of the disorder may account for focal clustering in some geographic areas. Management should involve aggressive stratification of arrhythmia risk and may include medical, surgical, or device therapy. In contrast, the syndrome of right ventricular outflow tract tachycardia, including nonischemic exercise-induced and repetitive monomorphic ventricular tachycardia, is a more benign entity. Management often involves beta- and calcium channel blocking drugs or type IC antiarrhythmic drugs. Catheter ablation of the arrhythmia focus in the right ventricular outflow tract has been used in selected patients. In this syndrome the right ventricle is normal, and noninvasive testing as well as electrophysiologic studies can be helpful in distinguishing it from the more malignant right ventricular dysplasia. Ventricular arrhythmias may also be seen after right ventricular incision, as in surgical repair of tetralogy of Fallot and ventricular septal defects. Significant ventricular ectopy associated with an abnormal right ventricle (enlarged or depressed systolic function) is associated with an increased risk for sustained arrhythmia and sudden cardiac death in this group. The optimal indicator(s) of highest risk in these patients remains under investigation but will likely include electrophysiologic testing. Bifascicular block occurs commonly after repair of tetralogy of Fallot, but is usually benign. Isolated right ventricular infarction is rare. Most right ventricular arrhythmias associated with ischemia occur in the setting of iatrogenic catheter manipulation for pacing or hemodynamic monitoring. In conclusion, right ventricular arrhythmias involve an unusual and interesting group of clinical entities and appear to span the spectrum of arrhythmias mechanisms. A macroreentrant activation ring around the ventriculotomy scar may account for the arrhythmias following repair of tetralogy of Fallot. Microreentry at sites of morphologic abnormalities results in the arrhythmias associated with right ventricular dysplasia and ischemia. Triggered activity related to DADs or, less likely, abnormal automaticity, produce repetitive monomorphic ventricular tachycardia and nonischemic exercise-induced ventricular tachycardia, both of which usually originate from the right ventricular outflow tract. Iatrogenic ventricular tachycardia associated with catheter manipulation is especially likely to occur in the presence of right ventricular ischemia and infarction. It is important to recognize these clinical entities because treatment is specific.(ABSTRACT TRUNCATED AT 400 WORDS)

Epilepsy and mental decline.

Experience with prolonged seizures in animal models and humans teaches that cellular injury and cognitive impairment can occur in epilepsy. Status epilepticus probably causes cerebral injury and cognitive dysfunction if it is of long duration; however, studies of electroconvulsive therapy do not support the idea that repeated seizures alone produce a decline in cognitive function. Although many factors related to seizures may correlate with cognitive impairment in certain groups of patients with epilepsy, prospective studies do not support the premise that cognitive impairment develops or progresses in a population of epilepsy patients. When impairment is present, its origin appears to be multifactorial. In addition to the seizures and associated seizure variables (including anticonvulsant medications), interictal epileptiform discharges and the perceptions of the patients and others also may play major roles.

Information exchange in an epilepsy forum on the World Wide Web.

The Partners Healthcare Epilepsy Service hosts an epilepsy 'Webforum'. In this paper, we describe our observations regarding who uses it, what kind of information is exchanged, how much misinformation is present and how we can better serve our patients. We examined a sample of 155 posts to the forum and 342 responses to those posts. The individual making the post and the type of questions were categorized. We also determined whether any information was objectively inaccurate. The principal users were care-givers (49%) and patients (34%). Eighty percent of the primary posts were questions. Answers were given largely by patients (38%) and care-givers (34%). The most commonly asked questions were about treatment options (31%) and the natural history of the illness (28%). In 20% of the questions, the user incidentally remarked that a health-care provider had not met their information needs. Six percent of the information was objectively inaccurate. The Web can serve as an effective means for the exchange of information between individuals with a common medical condition. We found that a small amount of misinformation is exchanged and that health-care providers are sometimes perceived as unable or unwilling to supply important health-related information.

Evaluation of Roche Diagnostics ONLINE DAT II, a new generation of assays for the detection of drugs of abuse.

A new generation of ONLINE assays has been developed that offers improved performance and enhanced ease of use. This family of assays is being applied to both the COBAS INTEGRA and Roche/Hitachi line of analyzers. The four ONLINE DAT II assays that were evaluated included cocaine (benzoylecgonine) (BE), methadone (MDN), opiates (OP), and tetrahydrocannabinol (THC). The BE assay has a dual cutoff (150/300 ng/mL) with a dynamic range from 0 to 5000 ng/mL. The MDN assay has a cutoff of 300 ng/mL with a dynamic range from 0 to 2000 ng/mL. The opiates assay has a 300 ng/mL cutoff with a 0 to 2000 ng/mL range and a 2000 ng/mL cutoff with a 0 to 8000 ng/mL range. The THC assay has 20, 50, and 100 ng/mL cutoffs with 0 to 100, 0 to 300, and 0 to 300 ng/mL dynamic ranges, respectively. The ranges of the intra-assay precision (coefficients of variation for n = 20) run in the semiquantitative mode are 2.3-7.5% for BE, 2.0-3.8% for MDN, 1.9-4.2% for OP, and 3.9-5.2% for THC. The intra-assay qualitative precision for all of the assays as calculated from absorbance values is generally higher than that of the intra-assay semiquantitative precision at the cutoff. The qualitative precision ranges between 0.4% and 3.1%. The standard curve stability defined for the COBAS INTEGRA systems for these reagents ranges from 35 to 68 days. The clinical sensitivity and specificity were compared to the OnLine generation I and CEDIA immunoassays, as well as gas chromatography-mass spectrometry (GC-MS). The results indicate that for each assay, the sensitivity and specificity were the same or greater when compared to the other two immunoassay technologies. The results of each assay also correlated very well (> 99%) when compared with GC-MS.