Faciobrachial dystonic seizures: the influence of immunotherapy on seizure control and prevention of cognitive impairment in a broadening phenotype.

Voltage-gated potassium channel complex antibodies, particularly those directed against leucine-rich glioma inactivated 1, are associated with a common form of limbic encephalitis that presents with cognitive impairment and seizures. Faciobrachial dystonic seizures have recently been reported as immunotherapy-responsive, brief, frequent events that often predate the cognitive impairment associated with this limbic encephalitis. However, these observations were made from a retrospective study without serial cognitive assessments. Here, we undertook the first prospective study of faciobrachial dystonic seizures with serial assessments of seizure frequencies, cognition and antibodies in 10 cases identified over 20 months. We hypothesized that (i) faciobrachial dystonic seizures would show a differential response to anti-epileptic drugs and immunotherapy; and that (ii) effective treatment of faciobrachial dystonic seizures would accelerate recovery and prevent the development of cognitive impairment. The 10 cases expand both the known age at onset (28 to 92 years, median 68) and clinical features, with events of longer duration, simultaneously bilateral events, prominent automatisms, sensory aura, and post-ictal fear and speech arrest. Ictal epileptiform electroencephalographic changes were present in three cases. All 10 cases were positive for voltage-gated potassium channel-complex antibodies (346-4515 pM): nine showed specificity for leucine-rich glioma inactivated 1. Seven cases had normal clinical magnetic resonance imaging, and the cerebrospinal fluid examination was unremarkable in all seven tested. Faciobrachial dystonic seizures were controlled more effectively with immunotherapy than anti-epileptic drugs (P = 0.006). Strikingly, in the nine cases who remained anti-epileptic drug refractory for a median of 30 days (range 11-200), the addition of corticosteroids was associated with cessation of faciobrachial dystonic seizures within 1 week in three and within 2 months in six cases. Voltage-gated potassium channel-complex antibodies persisted in the four cases with relapses of faciobrachial dystonic seizures during corticosteroid withdrawal. Time to recovery of baseline function was positively correlated with time to immunotherapy (r = 0.74; P = 0.03) but not time to anti-epileptic drug administration (r = 0.55; P = 0.10). Of 10 cases, the eight cases who received anti-epileptic drugs (n = 3) or no treatment (n = 5) all developed cognitive impairment. By contrast, the two who did not develop cognitive impairment received immunotherapy to treat their faciobrachial dystonic seizures (P = 0.02). In eight cases without clinical magnetic resonance imaging evidence of hippocampal signal change, cross-sectional volumetric magnetic resonance imaging post-recovery, after accounting for age and head size, revealed cases (n = 8) had smaller brain volumes than healthy controls (n = 13) (P < 0.001). In conclusion, faciobrachial dystonic seizures can be prospectively identified as a form of epilepsy with an expanding phenotype. Immunotherapy is associated with excellent control of the frequently anti-epileptic drug refractory seizures, hastens time to recovery, and may prevent the subsequent development of cognitive impairment observed in this study.

Faciobrachial dystonic seizures precede Lgi1 antibody limbic encephalitis.

OBJECTIVE: To describe a distinctive seizure semiology that closely associates with voltage-gated potassium channel (VGKC)-complex/Lgi1 antibodies and commonly precedes the onset of limbic encephalitis (LE). METHODS: Twenty-nine patients were identified by the authors (n = 15) or referring clinicians (n = 14). The temporal progression of clinical features and serum sodium, brain magnetic resonance imaging (MRI), positron emission tomography/single photon emission computed tomography, and VGKC-complex antibodies was studied. RESULTS: Videos and still images showed a distinctive adult-onset, frequent, brief dystonic seizure semiology that predominantly affected the arm and ipsilateral face. We have termed these faciobrachial dystonic seizures (FBDS). All patients tested during their illness had antibodies to VGKC complexes; the specific antigenic target was Lgi1 in 89%. Whereas 3 patients never developed LE, 20 of the remaining 26 (77%) experienced FBDS prior to the development of the amnesia and confusion that characterize LE. During the prodrome of FBDS alone, patients had normal sodium and brain MRIs, but electroencephalography demonstrated ictal epileptiform activity in 7 patients (24%). Following development of LE, the patients often developed other seizure semiologies, including typical mesial temporal lobe seizures. At this stage, investigations commonly showed hyponatremia and MRI hippocampal high T2 signal; functional brain imaging showed evidence of basal ganglia involvement in 5/8. Antiepileptic drugs (AEDs) were generally ineffective and in 41% were associated with cutaneous reactions that were often severe. By contrast, immunotherapies produced a clear, and often dramatic, reduction in FBDS frequency. INTERPRETATION: Recognition of FBDS should prompt testing for VGKC-complex/Lgi1 antibodies. AEDs often produce adverse effects; treatment with immunotherapies may prevent the development of LE with its potential for cerebral atrophy and cognitive impairment.

Dravet syndrome as epileptic encephalopathy: evidence from long-term course and neuropathology.

Dravet syndrome is an epilepsy syndrome of infantile onset, frequently caused by SCN1A mutations or deletions. Its prevalence, long-term evolution in adults and neuropathology are not well known. We identified a series of 22 adult patients, including three adult post-mortem cases with Dravet syndrome. For all patients, we reviewed the clinical history, seizure types and frequency, antiepileptic drugs, cognitive, social and functional outcome and results of investigations. A systematic neuropathology study was performed, with post-mortem material from three adult cases with Dravet syndrome, in comparison with controls and a range of relevant paediatric tissue. Twenty-two adults with Dravet syndrome, 10 female, were included, median age 39 years (range 20-66). SCN1A structural variation was found in 60% of the adult Dravet patients tested, including one post-mortem case with DNA extracted from brain tissue. Novel mutations were described for 11 adult patients; one patient had three SCN1A mutations. Features of Dravet syndrome in adulthood include multiple seizure types despite polytherapy, and age-dependent evolution in seizure semiology and electroencephalographic pattern. Fever sensitivity persisted through adulthood in 11 cases. Neurological decline occurred in adulthood with cognitive and motor deterioration. Dysphagia may develop in or after the fourth decade of life, leading to significant morbidity, or death. The correct diagnosis at an older age made an impact at several levels. Treatment changes improved seizure control even after years of drug resistance in all three cases with sufficient follow-up after drug changes were instituted; better control led to significant improvement in cognitive performance and quality of life in adulthood in two cases. There was no histopathological hallmark feature of Dravet syndrome in this series. Strikingly, there was remarkable preservation of neurons and interneurons in the neocortex and hippocampi of Dravet adult post-mortem cases. Our study provides evidence that Dravet syndrome is at least in part an epileptic encephalopathy.

Epilepsy causing pupillary hippus: an unusual semiology.

Altered pupillary behavior is commonly present during and following epileptic seizures, but symptomatic pupillary hippus as the main feature of a seizure has not been reported in the modern literature. We present the case of a woman with epileptic seizures consisting of sustained fluctuation of perception of brightness. Bilateral pupillary hippus is the main semiologic feature.This autonomic phenomenon is selective for the pupils and does not involve other autonomic-mediated responses. An ictal video illustrates this phenomenon. The epileptogenic region, determined by ictal scalp and intracranial electroencephalography (EEG), is localized in the right posterior parietooccipital areas. Pupillary reflexes can be overridden by cortical input; here authors review the literature and discus the physiologic mechanisms underlying this autonomic phenomenon. Fluctuation in perceptual brightness during epileptic seizures may have a basis in ictal pupillary hippus.

Participation in Community Gardening: Sowing the Seeds of Well-Being: Participation au jardinage communautaire : pour semer les graines du bien-être.

BACKGROUND.: Sustaining well-being challenges people with serious mental health issues. Community gardening is an occupation used to promote clients' well-being, yet there is limited evidence to support this intervention. PURPOSE.: This paper examines how facilitated community gardening programs changed the subjective well-being and social connectedness of people living with mental health issues. METHOD.: A community-based participatory research approach and qualitative methods were used with 23 adults living in supported housing and participating in supported community gardening programs. A constructivist approach guided inductive data analysis. FINDINGS.: Participation in community gardening programs enhanced well-being through welcoming places, a sense of belonging, and developing positive feelings through doing. The connection to living things and responsibility for plants grounded participants in the present and offered a unique venue for learning about gardening and themselves. IMPLICATIONS.: Practitioners and service-users should collaborate to develop leadership, programs, places, and processes within community gardens to enhance well-being.

EEG correlated functional MRI and postoperative outcome in focal epilepsy.

BACKGROUND: The main challenge in assessing patients with epilepsy for resective surgery is localising seizure onset. Frequently, identification of the irritative and seizure onset zones requires invasive EEG. EEG correlated functional MRI (EEG-fMRI) is a novel imaging technique which may provide localising information with regard to these regions. In patients with focal epilepsy, interictal epileptiform discharge (IED) correlated blood oxygen dependent level (BOLD) signal changes were observed in approximately 50% of patients in whom IEDs are recorded. In 70%, these are concordant with expected seizure onset defined by non-invasive electroclinical information. Assessment of clinical validity requires post-surgical outcome studies which have, to date, been limited to case reports of correlation with intracranial EEG. The value of EEG-fMRI was assessed in patients with focal epilepsy who subsequently underwent epilepsy surgery, and IED correlated fMRI signal changes were related to the resection area and clinical outcome. METHODS: Simultaneous EEG-fMRI was recorded in 76 patients undergoing presurgical evaluation and the locations of IED correlated preoperative BOLD signal change were compared with the resected area and postoperative outcome. RESULTS: 21 patients had activations with epileptic activity on EEG-fMRI and 10 underwent surgical resection. Seven of 10 patients were seizure free following surgery and the area of maximal BOLD signal change was concordant with resection in six of seven patients. In the remaining three patients, with reduced seizure frequency post-surgically, areas of significant IED correlated BOLD signal change lay outside the resection. 42 of 55 patients who had no IED related activation underwent resection. CONCLUSION: These results show the potential value of EEG-fMRI in presurgical evaluation.

When do psychogenic nonepileptic seizures occur on a video/EEG telemetry unit?

To maximize the efficiency of diagnostic video/EEG telemetry, we retrospectively studied the occurrence of clinical events during admission in 254 patients. One hundred fifty-nine patients had psychogenic nonepileptic seizures (PNES) and 95 had epileptic seizures (ES). Twenty-five with PNES and none with ES had an event before or during electrode placement (P<0.0001). In the remaining 229, the initial event occurred within 48 hours of electrode placement in 98.5% patients with PNES and 100.0% of patients with ES. Time to occurrence of initial event did not differ between groups (P=0.69). 17.1% patients with PNES and 51.6% with ES had events between 12 AM and 6 AM (P=0.001). In conclusion, during diagnostic video/EEG telemetry, most patients who experience PNES or ES have diagnostic, typical events within 2 days. Although time to initial event after electrode placement does not differ between diagnoses, events prior to or during placement are most likely PNES and events at night are most likely ES.

Mosaicism of a missense SCN1A mutation and Dravet syndrome in a Roma/Gypsy family.

SCN1A mutations account for a large proportion of Dravet syndrome patients, and are reported in other cases of epilepsy, such as some families with genetic epilepsy with febrile seizures plus (GEFS+). While most Dravet syndrome cases are caused by de novo mutations, 5% inherit a mutation from a mildly affected or symptom-free parent. Parental mosaicism has been identified, with documented cases involving truncating mutations or gene rearrangements. We describe a Roma/Gypsy family, where a missense mutation in SCN1A, p.D194N, is transmitted from a mosaic GEFS+ father to a child with Dravet syndrome. Mosaicism may be more common than assumed and should be considered regardless of the nature of the mutation.

Partial epilepsy syndrome in a Gypsy family linked to 5q31.3-q32.

PURPOSE: The restricted genetic diversity and homogeneous molecular basis of Mendelian disorders in isolated founder populations have rarely been explored in epilepsy research. Our long-term goal is to explore the genetic basis of epilepsies in one such population, the Gypsies. The aim of this report is the clinical and genetic characterization of a Gypsy family with a partial epilepsy syndrome. METHODS: Clinical information was collected using semistructured interviews with affected subjects and informants. At least one interictal electroencephalography (EEG) recording was performed for each patient and previous data obtained from records. Neuroimaging included structural magnetic resonance imaging (MRI). Linkage and haplotype analysis was performed using the Illumina IVb Linkage Panel, supplemented with highly informative microsatellites in linked regions and Affymetrix SNP 5.0 array data. RESULTS: We observed an early-onset partial epilepsy syndrome with seizure semiology strongly suggestive of temporal lobe epilepsy (TLE), with mild intellectual deficit co-occurring in a large proportion of the patients. Psychiatric morbidity was common in the extended pedigree but did not cosegregate with epilepsy. Linkage analysis definitively excluded previously reported loci, and identified a novel locus on 5q31.3-q32 with an logarithm of the odds (LOD) score of 3 corresponding to the expected maximum in this family. DISCUSSION: The syndrome can be classified as familial temporal lobe epilepsy (FTLE) or possibly a new syndrome with mild intellectual deficit. The linked 5q region does not contain any ion channel-encoding genes and is thus likely to contribute new knowledge about epilepsy pathogenesis. Identification of the mutation in this family and in additional patients will define the full phenotypic spectrum.

Extratemporal ictal clinical features in hippocampal sclerosis: their relationship to the degree of hippocampal volume loss and to the outcome of temporal lobectomy.

PURPOSE: Since extratemporal clinical features in patients with unilateral hippocampal sclerosis (HS) are likely to indicate aberrant ictal spread or a more extensive epileptogenic zone, we asked whether such features are associated with more severe HS and a worse outcome following temporal lobectomy. PATIENTS AND METHODS: We reviewed all patients (174) who had undergone temporal lobectomy for histologically proven unilateral HS related temporal lobe epilepsy between 1997-2005 at the National Hospital for Neurology and Neurosurgery. We divided patients into those with severe HS (side-to-side ratio < 0.6) and those with mild HS (side-to-side ratio > 0.75). We examined all seizures recorded on electroencephalography (EEG) video telemetry in these patients for clinical features of temporal lobe epilepsy. The postsurgical outcome was classified using the Engel classification at the time of follow up (median 4.7 years, range 1-9 years). RESULTS: Patients (28 out 39) with severe HS had atypical features compared to 7 out of 27 in the mild HS [Chi square (chi(2)) test, p = 0.0013]. The mean number of atypical clinical features was 2.2 in the severe HS group and 0.62 in the mild HS group (Mann Whitney U Test, p < 0.001). The percentage of postsurgery seizure freedom (class 1 Engel classification) was 87%, and there was no significant effect of the presence of atypical clinical features. CONCLUSIONS: This study shows that atypical (extratemporal) clinical features tend to occur more frequently in patients with severe HS and do not correlate with worse surgical outcome.

The prognostic value of long-term ambulatory electroencephalography in antiepileptic drug reduction in adults with learning disability and epilepsy in long-term remission.

We determined the additional yield of ambulatory over routine electroencephalography recordings in predicting seizure recurrence after antiepileptic drug (AED) withdrawal in 15 adult patients with various epilepsy syndromes who had been seizure free for at least 3 years (median=10 years). Eleven of 15 patients (74%) relapsed during or after AED withdrawal. All six patients with epileptiform discharges on ambulatory electroencephalography prior to AED withdrawal relapsed, compared with five of nine patients without epileptiform discharges. Ambulatory electroencephalography significantly increases the yield in detecting epileptiform discharges (n=6) compared with routine electroencephalography (n=1). A negative electroencephalographic finding is only a poor predictor of seizure freedom following AED withdrawal. On clinical grounds, our data suggest that patients with epilepsy, learning disability, and other known risk factors (history of abnormal EEGs and frequent seizures, abnormal MRI) are at great risk of seizure relapse during AED taper, irrespective of very long periods of seizure freedom.

EEG-fMRI mapping of asymmetrical delta activity in a patient with refractory epilepsy is concordant with the epileptogenic region determined by intracranial EEG.

We studied a patient with refractory focal epilepsy using continuous EEG-correlated fMRI. Seizures were characterized by head turning to the left and clonic jerking of the left arm, suggesting a right frontal epileptogenic region. Interictal EEG showed occasional runs of independent nonlateralized slow activity in the delta band with right frontocentral dominance and had no lateralizing value. Ictal scalp EEG had no lateralizing value. Ictal scalp EEG suggested right-sided central slow activity preceding some seizures. Structural 3-T MRI showed no abnormality. There was no clear epileptiform abnormality during simultaneous EEG-fMRI. We therefore modeled asymmetrical EEG delta activity at 1-3 Hz near frontocentral electrode positions. Significant blood oxygen level-dependent (BOLD) signal changes in the right superior frontal gyrus correlated with right frontal oscillations at 1-3 Hz but not at 4-7 Hz and with neither of the two frequency bands when derived from contralateral or posterior electrode positions, which served as controls. Motor fMRI activations with a finger-tapping paradigm were asymmetrical: they were more anterior for the left hand compared with the right and were near the aforementioned EEG-correlated signal changes. A right frontocentral perirolandic seizure onset was identified with a subdural grid recording, and electric stimulation of the adjacent contact produced motor responses in the left arm and after discharges. The fMRI localization of the left hand motor and the detected BOLD activation associated with modeled slow activity suggest a role for localization of the epileptogenic region with EEG-fMRI even in the absence of clear interictal discharges.

Use of PASRR programs to assess serious mental illness and service access in nursing homes.

OBJECTIVE: This study assessed the implementation of state Preadmission Screening and Resident Review (PASRR) programs with respect to identification of serious mental illness among nursing facility applicants and residents and access to mental health services. METHODS: A national survey was conducted with representatives from agencies that implement PASRR in all 50 states and the District of Columbia. Also, 44 states sent PASRR data for review. Four states were selected for an in-depth study; six nursing homes per state were selected and one staff member from each facility was interviewed (N=24). Medical records were reviewed for 30 to 40 residents from each facility who met criteria for potentially having a disabling serious mental illness (N=786). RESULTS: Medical records showed that 50 percent of patients at the time of admission and 68 percent of patients at the time of the record review had a psychiatric diagnosis, typically a diagnosis of depressive disorder. At the time of admission, fewer records identified individuals with a serious mental illness (9 to 20 percent) or a primary diagnosis of any psychiatric illness (5 to 12 percent). Many records indicated that in-depth, required PASRR screens were not performed. Ninety percent of the states reported that Medicaid covers only basic psychiatric consultation services, such as medication monitoring, in nursing facilities. Between 30 and 32 percent of national survey respondents also characterized access to facilities that provide mental health services as limited and of variable quality. Although all 24 nursing facilities reported providing psychiatric consultation services, access to other mental health services, such as psychosocial rehabilitation or individual counseling, varied considerably. CONCLUSIONS: Nursing facility compliance with administration and documentation of PASRR screens appears problematic. Nevertheless, there do not appear to be excessively high numbers of residents with serious mental illness, suggesting that state PASRR programs may contribute positively to the identification of people with serious mental illness. However, many nursing facility residents have some type of psychiatric illness, and PASRR legislation does not appear to have enhanced their ability to gain access to mental health services beyond standard psychiatric consultation and medication therapy.

Nonconvulsive status epilepticus: Epilepsy Research Foundation workshop reports.

In April 2004, a group of physicians with an interest in nonconvulsive status epilepticus representing a spectrum of opinion met in Oxford, sponsored by the Epilepsy Research Foundation (a charitable organization), to discuss and debate the definition, diagnosis and treatment of nonconvulsive status epilepticus. We felt that such a meeting would be useful, as nonconvulsive status epilepticus is a subject that provokes strong reactions, perhaps largely due to the relative lack of evidence and the surfeit of opinion. The meeting was arranged such that there were formal talks followed by a discussion led by one of the attendees. We present here the extended abstracts of the main talks with the points raised by the discussants. Despite disagreements on certain issues there was much in the way of consensus. First, it was agreed that nonconvulsive status epilepticus is a term that covers a range of disparate conditions with varying prognoses and treatments. The agreed definition was thus suitably vague, A<>. Secondly, it was agreed that even within a specific condition (e.g. complex partial status epilepticus), the prognosis and treatment depends upon the context in which the condition occurs (e.g. in the critically ill, in coma, in the A<> and in people with prior epilepsy). Perhaps, most importantly it was agreed that we lacked good clinical data, and the challenge was to design good studies for a condition that is underrecognised and often difficult to diagnose.

Preventive mental health and substance abuse programs and services in managed care.

If effective preventive behavioral health services were available to the millions of Americans enrolled in managed care organizations, the public health impact could be significant. This project sought to summarize published research-based information about effective preventive interventions for mental health and substance use (tobacco, alcohol, and other drugs) shown or likely to have no negative cost impact. Fifty-four studies satisfied seven screening criteria. Their findings demonstrated that preventive behavioral health interventions appropriate for managed care settings have been evaluated and have been shown to be effective. Some produced cost savings or offset costs. Six preventive behavioral health interventions are therefore recommended for managed care.

County workforce, reimbursement, and organizational factors associated with behavioral health capacity in health centers.

This study describes on-site behavioral health treatment capacity in health centers in 2007 and examines whether capacity was associated with health center characteristics, county-level behavioral health workforce, and same-day billing restrictions. Cross-sectional data from the 2007 Area Resource File and Uniform Data System were linked with data on Medicaid same-day billing restrictions. Mental health treatment capacity was common; almost four in five health centers provided on-site mental health services. Additional services such as crisis counseling (20 %), treatment from a psychiatrist (29 %), and substance abuse treatment were offered by fewer health centers (51 % provide on-site services and only 20 % employ substance abuse specialists). In multivariate analysis, larger health centers, health centers located in counties with a larger behavioral health workforce per capita, and those located in the West and Northeast were more likely to have behavioral health capacity. Same-day billing restrictions were associated with lower odds of substance use treatment capacity and providing 24 hr crisis counseling services.

Hospital readmission among medicaid patients with an index hospitalization for mental and/or substance use disorder.

Hospital readmission rates are increasingly used as a performance indicator. Whether they are a valid, reliable, and actionable measure for behavioral health is unknown. Using the MarketScan Multistate Medicaid Claims Database, this study examined hospital- and patient-level predictors of behavioral health readmission rates. Among hospitals with at least 25 annual admissions, the median behavioral health readmission rate was 11% (10th percentile, 3%; 90th percentile, 18%). Increased follow-up at community mental health centers was associated with lower probabilities of readmission, although follow-up with other types of providers was not significantly associated with hospital readmissions. Hospital average length of stay was positively associated with lower readmission rates; however, the effect size was small. Patients with a prior inpatient stay, a substance use disorder, psychotic illness, and medical comorbidities were more likely to be readmitted. Additional research is needed to further understand how the provision of inpatient services and post-discharge follow-up influence readmissions.

Another cause of vaccine encephalopathy: a case of Angelman syndrome.

Dravet syndrome has been found recently as an important underlying condition in cases of alleged vaccine encephalopathy after pertussis vaccination, where vaccination seemed to have precipitated the occurrence of the disease without modifying the long-term course. We report on a patient diagnosed with Angelman syndrome in her fifth decade, in whom the intellectual disability and epilepsy had been assumed to be caused by a vaccine encephalopathy following smallpox vaccination. Clinical features of Angelman syndrome had faded away. The history of the present patient suggests that genetic conditions other than Dravet syndrome can be associated with an alleged vaccine encephalopathy. A history of vaccine encephalopathy is rare among patients with learning disability and refractory epilepsy (1.4% in our cohort), but it should lead to consideration of a comprehensive genetic work-up if Dravet syndrome is excluded. The early history of the patient, when available, should guide the investigations. Medico-legal aspects are also discussed.

Wearable electroencephalography. What is it, why is it needed, and what does it entail?

The electroencephalogram (EEG) is a classic noninvasive method for measuring a person's brain waves and is used in a large number of fields: from epilepsy and sleep disorder diagnosis to brain-computer interfaces (BCIs). Electrodes are placed on the scalp to detect the microvolt-sized signals that result from synchronized neuronal activity within the brain. Current long-term EEG monitoring is generally either carried out as an inpatient in combination with video recording and long cables to an amplifier and recording unit or is ambulatory. In the latter, the EEG recorder is portable but bulky, and in principle, the subject can go about their normal daily life during the recording. In practice, however, this is rarely the case. It is quite common for people undergoing ambulatory EEG monitoring to take time off work and stay at home rather than be seen in public with such a device. Wearable EEG is envisioned as the evolution of ambulatory EEG units from the bulky, limited lifetime devices available today to small devices present only on the head that can record EEG for days, weeks, or months at a time. Such miniaturized units could enable prolonged monitoring of chronic conditions such as epilepsy and greatly improve the end-user acceptance of BCI systems. In this article, we aim to provide a review and overview of wearable EEG technology, answering the questions: What is it, why is it needed, and what does it entail? We first investigate the requirements of portable EEG systems and then link these to the core applications of wearable EEG technology: epilepsy diagnosis, sleep disorder diagnosis, and BCIs. As a part of our review, we asked 21 neurologists (as a key user group) for their views on wearable EEG. This group highlighted that wearable EEG will be an essential future tool. Our descriptions here will focus mainly on epilepsy and the medical applications of wearable EEG, as this is the historical background of the EEG, our area of expertise, and a core motivating area in itself, but we will also discuss the other application areas. We continue by considering the forthcoming research challenges, principally new electrode technology and lower power electronics, and we outline our approach for dealing with the electronic power issues. We believe that the optimal approach to realizing wearable EEG technology is not to optimize any one part but to find the best set of tradeoffs at both the system and implementation level. In this article, we discuss two of these tradeoffs in detail: investigating the online compression of EEG data to reduce the system power consumption and the optimal method for providing this data compression.