Electrical stimulation of the anterior nucleus of the thalamus for the treatment of intractable epilepsy

PURPOSE

Animal studies and sporadic case reports in human subjects have suggested that intermittent electrical stimulation of the anterior nucleus of the thalamus reduces seizure activity. We embarked on an open-label pilot study to determine initial safety and tolerability of bilateral stimulation of the anterior nucleus of the thalamus (ANT), to determine a range of appropriate stimulation parameters, and to begin to gather pilot efficacy data.

METHODS

We report an open-label pilot study of intermittent electrical stimulation of the anterior nucleus of the thalamus in five patients (three men, two women; age range, 24-47 years), with follow-up between 6 and 36 months. All patients had intractable partial epilepsy. Four of the five patients also had secondarily generalized seizures. Stimulation was delivered by bilateral implantable, programmable devices by using an intermittent, relatively high-frequency protocol. Stimulation parameters were 100 cycles per second with charge-balanced alternating current; pulse width, 90 ms; and voltages ranging between 1.0 and 10.0 V. Seizure counts were monitored and compared with preimplantation baseline.

RESULTS

Four of the five patients showed clinically and statistically significant improvement with respect to the severity of their seizures, specifically with respect to the frequency of secondarily generalized tonic-clonic seizures and complex partial seizures associated with falls. One patient showed a statistically significant reduction in total seizure frequency. No adverse events could clearly be attributed to stimulation. None of the patients could determine whether the stimulator was on or off at these parameters.

CONCLUSIONS

Electrical stimulation of the ANT appears to be well tolerated. Preliminary evidence suggests clinical improvement in seizure control in this small group of intractable patients. Further controlled study of deep brain stimulation of the anterior nucleus is warranted.

The movement disorder of reflex sympathetic dystrophy

We present 43 patients with reflex sympathetic dystrophy (RSD) who manifested abnormalities of movement. The patients have focal dystonia, weakness, spasms, tremor, difficulty initiating movement, and increased tone and reflexes. These motor signs and symptoms may precede other manifestations of the illness by weeks or months. They most frequently, but not invariably, occur concomitantly with sudomotor or vasomotor changes and pain. Lioresal is effective in reducing spasms. Early in the course of RSD, the motor manifestation may be alleviated by intense sympathetic blockade or sympathectomy. In many patients, the movement disorder becomes independent of sympathetic innervation.

Transcallosal resection of hypothalamic hamartoma for intractable epilepsy

PURPOSE

To present the results of transcallosal surgical resection of hypothalamic hamartoma (HH) in 26 patients with refractory epilepsy in a prospective outcome study.

METHODS

Patients with refractory epilepsy symptomatic to HH were referred for surgical resection of their HH (mean age, 10.0 years; range, 2.1-24.2 years). A transcallosal, interforniceal approach was used to remove and/or disconnect the hamartoma. Volumetry was obtained on pre- and postoperative brain MRI scans to determine percentage of resection. Outcome assessment included determination of postoperative seizure frequencies in comparison to baseline and the incidence of postoperative complications. Postoperative changes in cognitive and behavioral functioning, in comparison to baseline, were elicited by parental report.

RESULTS

The average postoperative follow-up interval was 20.3 months (range, 13-28 months). Fourteen (54%) patients were completely seizure free, and nine (35%) had at least a 90% improvement in total seizure frequency. Parents reported postoperative improvement in behavior in 23 (88%) patients and in cognition in 17 (65%) patients. Transient postoperative memory disturbance was seen in 15 (58%) patients, but persisted in only two (8%). Two (8%) patients had persisting endocrine disturbance requiring hormone replacement therapy (diabetes insipidus and hypothyroidism in one each). With univariate analysis, the likelihood of a seizure-free outcome correlated with younger age, shorter lifetime duration of epilepsy, smaller preoperative HH volume, and 100% HH resection.

CONCLUSIONS

Refractory epilepsy associated with HH can be safely and effectively treated with surgical resection by a transcallosal, interforniceal approach. Short-term memory deficits appear to be transient for most patients, and family perception of the impact of surgery on cognitive and behavioral domains is favorable. Complete resection yields the best result.

The effect of disease, functional status, and relapses on the utility of people with multiple sclerosis in the UK

OBJECTIVES

Because published utility estimates in multiple sclerosis (MS) are concentrated in people with moderate to severe disease severity and focus on specific types of MS, we conducted a cross-sectional study of people with MS to estimate the utility associated with disease, functional status as measured by the Adapted Patient Determined Disease Steps (APDDS) Scale, and relapse to enhance knowledge of the association of these factors and utility.

METHODS

The study was conducted by a postal questionnaire sent to 12,968 people in a database managed by a UK charity (the MS Trust). Utility was assessed using the EQ-5D multiattribute utility scale. The APDDS is closely related to the more commonly reported Expanded Disability Status Scale (EDSS).

RESULTS

A total of 2708 (20.9%) questionnaires were returned and 2048 (15.8%) respondents provided data suitable for analysis. The mean age of the sample was 51 years, and 22.5% of people were aged 60 years or more. Disease severity was concentrated in people with moderately severe MS (EDSS 4-6.5), with 21%, 60%, and 19% of people reporting mild, moderate, and severe disease, respectively. Results show that disease severity has an inverse relationship with utility. The mean utility is 0.491. Utility varies between 0.870 and -0.195 for EDSS states 0 and 9. Number of years since diagnosis, type of disease, and recent relapse status are also all significantly associated with utility.

CONCLUSIONS

The results are comparable with previous published utility estimates. We have demonstrated a clear relationship between functional status, disease type, relapse status, duration of illness, and utility. As a set of coefficients, the utility estimates we have calculated may be used to compare the quality of life of people with MS with other illnesses and to inform future economic evaluations in MS.

Adjunctive therapy with oxcarbazepine in children with partial seizures. The Oxcarbazepine Pediatric Study Group

OBJECTIVE

To evaluate the safety and efficacy of oxcarbazepine (OXC) as adjunctive therapy in children with inadequately controlled partial seizures on one or two concomitant antiepileptic drugs (AEDs).

BACKGROUND

OXC has shown antiepileptic activity in several comparative monotherapy trials in newly diagnosed patients with epilepsy, and in a placebo-controlled monotherapy trial in hospitalized patients evaluated for epilepsy surgery.

DESIGN

A total of 267 patients were evaluated in a multicenter, randomized, placebo-controlled trial consisting of three phases: 1) a 56-day baseline phase (patients maintained on their current AEDs); 2) a 112-day double-blind treatment phase (patients received either OXC 30-46 mg/kg/day orally or placebo); and 3) an open-label extension phase. Data are reported only from the double-blind treatment phase; the open-label extension phase is ongoing.

METHODS

Children (3 to 17 years old) with inadequately controlled partial seizures (simple, complex, and partial seizures evolving to secondarily generalized seizures) were enrolled.

RESULTS

Patients treated with OXC experienced a significantly greater median percent reduction from baseline in partial seizure frequency than patients treated with placebo (p = 0.0001; 35% versus 9%, respectively). Forty-one percent of patients treated with OXC experienced a > or =50% reduction from baseline in partial seizure frequency per 28 days compared with 22% of patients treated with placebo (p = 0.0005). Ninety-one percent of the group treated with OXC and 82% of the group treated with placebo reported > or =1 adverse event; vomiting, somnolence, dizziness, and nausea occurred more frequently (twofold or greater) in the group treated with OXC.

CONCLUSION

OXC adjunctive therapy administered in a dose range of 6 to 51 mg/kg/day (median 31.4 mg/kg/day) is safe, effective, and well tolerated in children with partial seizures.

The hypothalamic hamartoma: a model of subcortical epileptogenesis and encephalopathy

Although uncommon, the hypothalamic hamartoma (HH) is often associated with a devastating clinical syndrome, which may include refractory epilepsy, progressive cognitive decline, and deterioration in behavioral and psychiatric functioning. Contrary to conventional thinking which attributed seizure origin to cortical structures, the hamartoma itself has now been firmly established as the site of intrinsic epileptogenesis for the gelastic seizures (i.e., characterized by unusual mirth) peculiar to this disorder. It also appears that the HH contributes to a process of secondary epileptogenesis, with eventual cortical seizure onset of multiple types in some patients. Anticonvulsant medications are known to be poorly effective in this disorder. Treatment, including some innovative approaches to surgical resection, is now targeted directly at the HH itself, with impressive results. Younger patients, in particular, may avoid the deteriorating course described earlier. Access to tissue from larger numbers of patients at single or collaborating centers specializing in HH surgery will allow for research into the fundamental mechanisms producing this little understood disorder. Refractory epilepsy associated with HH is the premier human model for subcortical epilepsy and an excellent model for secondary epileptogenesis and epileptic encephalopathy.

The painful shoulder during freestyle swimming. An electromyographic cinematographic analysis of twelve muscles

The purpose of this paper is to describe the patterns of activity of 12 shoulder muscles in painful shoulders, and compare those patterns of activity with normal shoulders. The results show significant differences in 7 of the 12 muscles. Those muscles included the anterior deltoid, middle deltoid, infraspinatus, subscapularis, upper trapezius, rhomboids, and the serratus anterior. There were no significant differences between muscle activity patterns of normal versus painful shoulders in the latissimus dorsi, pectoralis major, teres minor, supraspinatus, or the posterior deltoid. This information will contribute to the development of muscle conditioning programs to optimize performance and prevent injury, as well as develop programs for scientific rehabilitation strengthening.

The normal shoulder during freestyle swimming. An electromyographic and cinematographic analysis of twelve muscles

The shoulder in swimming is subjected to multiple factors that can lead to a high injury rate. To prevent injury, one must understand the biomechanics of swimming. This paper describes the electromyographic and cinematographic findings of 12 shoulder muscles in competitive swimmers without shoulder pain. The results show the three heads of the deltoid and the supraspinatus functioning in synchrony to place the arm at hand entry and exit, the rhomboids and upper trapezius to position the scapula for the arm, the pectoralis major and latissimus dorsi to propel the body, the subscapularis and serratus anterior as muscles with constant muscle activity, the teres minor functioning with the pectoralis major, and the infraspinatus active only to externally rotate the arm at midrecovery. This information is important to design optimal preventative and rehabilitative exercise programs.

A biochemical rationale for the anticancer effects of Hsp90 inhibitors: slow, tight binding inhibition by geldanamycin and its analogues

Heat shock protein (Hsp)90 is emerging as an important therapeutic target for the treatment of cancer. Two analogues of the Hsp90 inhibitor geldanamycin are currently in clinical trials. Geldanamycin (GA) and its analogues have been reported to bind purified Hsp90 with low micromolar potency, in stark contrast to their low nanomolar antiproliferative activity in cell culture and their potent antitumor activity in animal models. Several models have been proposed to account for the approximately 100-fold-greater potency in cell culture, including that GA analogues bind with greater affinity to a five-protein Hsp90 complex than to Hsp90 alone. We have determined that GA and the fluorescent analogue BODIPY-GA (BDGA) both demonstrate slow, tight binding to purified Hsp90. BDGA, used to characterize the kinetics of ligand-Hsp90 interactions, was found to bind Hsp90alpha with k(off) = 2.5 x 10(-3) min(-1), t(1/2) = 4.6 h, and Ki* = 10 nM. It was found that BDGA binds to a functional multiprotein Hsp90 complex with kinetics and affinity identical to that of Hsp90 alone. Also, BDGA binds to Hsp90 from multiple cell lysates in a time-dependent manner with similar kinetics. Therefore, our results indicate that the high potency of GA in cell culture and in vivo can be accounted for by its time-dependent, tight binding to Hsp90 alone. In the broader context, these studies highlight the essentiality of detailed biochemical characterization of drug-target interactions for the effective translation of in vitro pharmacology to cellular and in vivo efficacy.

Ganaxolone for treating intractable infantile spasms: a multicenter, open-label, add-on trial

This is a multicenter, open-label, add-on trial, investigating the safety and efficacy of ganaxolone (GNX) in a population of children with refractory infantile spasms, or with continuing seizures after a prior history of infantile spasms. A total of 20 children aged 7 months to 7 years were enrolled in this dose-escalation study, after baseline seizure frequencies were established. Concomitant antiepilepsy drugs were maintained throughout the study period. The dose of GNX was progressively increased to 36 mg/kg/d (or to the maximally tolerated dose) over a period of 4 weeks, then maintained for 8 weeks before tapering and discontinuation. Seizure diaries were maintained by the families, and spasm frequency was compared with the baseline period. The occurrence of adverse events was clinically monitored, and global evaluations of seizure severity and response to treatment were obtained. A total of 16 of the 20 subjects completed the study, 15 of whom had refractory infantile spasms at the time of study enrollment. Spasm frequency was reduced by at least 50% in 33% of these subjects, with an additional 33% experiencing some improvement (25-50% reduction in spasm frequency). Ganaxolone was well tolerated, and adverse events attributed to GNX were generally mild. Ganaxolone was safe and effective in treating this group of refractory infantile spasms patients in an open-label, add-on trial. Further investigation with randomized, controlled study design is warranted.

Hypothalamic hamartoma: basic mechanisms of intrinsic epileptogenesis

The hypothalamic hamartoma (HH) is a rare developmental malformation commonly associated with gelastic seizures that are notoriously refractory to medical therapy. Recent evidence supports the intrinsic seizure propensity of HH. Despite increasing clinical recognition of this condition, the mechanisms of seizure genesis in HH tissue remain unclear. This review summarizes the histochemical and electrophysiological properties of HH neurons, and relates these findings to those characteristics identified in other types of epileptic tissue. Initial studies have revealed two distinct populations of neurons in surgically resected HH tissue. One group consisted of small gamma-aminobutyric acid (GABA)-expressing neurons that occurred principally in clusters and displayed spontaneous rhythmic firing. The second group was composed of large, quiescent, pyramidal-like neurons with more extensive dendritic and axonal arborization. We propose that the small, spontaneously firing GABAergic neurons send inhibitory projections to and drive the synchrony of large output neurons. These observations constitute the basis for future investigations aimed at elucidating the mechanisms of subcortical epileptogenesis.

Cost-effectiveness analyses of natalizumab (Tysabri) compared with other disease-modifying therapies for people with highly active relapsing-remitting multiple sclerosis in the UK

BACKGROUND

Natalizumab (Tysabri) is a new disease-modifying therapy that has been shown to be clinically effective in patients with relapsing-remitting multiple sclerosis (RRMS) and has been licensed for use in patients with highly active RRMS (HARRMS). These patients are those who experience higher relapse rates and faster disability progression than the general RRMS population.

OBJECTIVES

To estimate the cost effectiveness of natalizumab compared with interferon-beta, glatiramer acetate and best supportive care from various UK cost perspectives.

METHODS

A 30-year Markov model was developed, based on previously published models for multiple sclerosis, to estimate transition between disability states and the probability of relapse within disability states. The model was parameterized with data from the UK Multiple Sclerosis (MS) Survey 2005 and data from the AFFIRM study, a 2-year multicentre, randomized, double-blind, placebo-controlled trial of natalizumab in RRMS patients. Additional data were sourced from the literature. A UK societal cost perspective was used in the base case, with additional cost perspectives considered in the sensitivity analysis. The baseline characteristics for the patient group were taken from the patient population in the AFFIRM study (mean age 36 years, mean time since diagnosis 5 years and a mean Kurtzke Extended Disability Status Scale [EDSS] score of 2.5). The model and its parameterization were designed and developed to support a reimbursement application for natalizumab submitted to the UK National Institute for Health and Clinical Excellence (NICE). Efficacies for natalizumab and glatiramer acetate were taken from clinical trial data, and for interferon-beta from a meta-analysis of clinical trial data. Disutilities from adverse events for each comparator were also included in the model. Outcomes and costs were discounted at 3.5% per anum. Costs for interferon-beta and glatiramer acetate were based on published prices (year 2006 values) under the UK Risk Sharing Scheme, and for natalizumab the UK NHS list price was used. Diagnostic, administration and adverse event costs were also included. The incremental cost-effectiveness ratios (ICERs) were calculated for the base case, and a probabilistic sensitivity analysis was performed to assess the probability of cost effectiveness at different willingness-to-pay thresholds.

RESULTS

The ICER for natalizumab compared with interferon-beta was 2300 pound per QALY. Compared with glatiramer acetate, it was 2000 pound per QALY, and compared with best supportive care it was 8200 pound per QALY. From a health and social care cost perspective, the ICERs were 18,700 pound, 20,400 pound and 25,500 per QALY, respectively. At a willingness-to-pay threshold of 30,000 pound per QALY, the probability of natalizumab being cost effective against any comparator from a societal perspective was >89%.

CONCLUSION

If UK society is willing to pay more than 8200 pound per QALY, or Health and Social Services are willing to pay more than 26,000 pound per QALY, this analysis suggests that natalizumab is likely to be a cost-effective treatment for all patients with HARRMS.

The Histopathology of Hypothalamic Hamartomas

Hypothalamic hamartomas (HHs) are rare developmental tumors that cause seizures or pituitary axis dysfunction, usually beginning in childhood. We analyzed HH tissue from 57 patients whose tumors were resected through recently developed transcallosal interforniceal and transventricular endoscopic surgical approaches. All cases were composed of abnormally distributed but cytologically normal neurons and glia, including fibrillary astrocytes and oligodendrocytes. Neuronal elements predominated in most cases, but a relative increase in astrocytic elements was seen with increasing age. All had various sized nodular foci of neurons as well as areas of diffusely distributed neurons with interspersed glial cells. Smaller neurons predominated, and most cases had only a few interspersed large ganglion cells. Immunohistochemistry demonstrated extensive production of synapse-associated proteins. Immunohistochemistry for phosphorylated and nonphosphorylated neurofilament and alpha-internexin demonstrated staining patterns consistent with mature neurons. In contrast to cortical dysplasia, atypical large ganglion-like balloon cells were almost never seen. In summary, although their number and distribution vary, mature smaller neurons were the most prominent and most consistent histologic feature of HH. Nodules of these small neurons were a universal feature of the microarchitecture of HH lesions associated with epilepsy. Characterization of these neurons may aid in understanding the mechanism of seizure development in HH.

Seizure outcome and complications following hypothalamic hamartoma treatment in adults: endoscopic, open, and Gamma Knife procedures

OBJECT

This study aimed at identifying outcomes with respect to seizures, morbidity, and mortality in adult patients undergoing resective or Gamma Knife surgery (GKS) to treat intractable epilepsy associated with hypothalamic hamartoma (HH).

METHODS

Adult patients undergoing surgical treatment for HH-related epilepsy were prospectively monitored at a single center for complications and seizure outcome by using a proprietary database. Preintervention and postintervention data for patients 18 years of age and older, and with at least 1 year of follow-up, were analyzed, with specific attention to seizure control, complications, hormonal status, and death.

RESULTS

Forty adult patients were found in the database (21 were women). The median HH volume was 0.54 cm(3). In 70% of patients, it was located inside the third ventricle, attached unilaterally and vertically to the hypothalamus (Delalande Type II). Most patients (26) underwent an endoscopic resection, 10 patients had a transcallosal or other type of open (pterional or orbitozygomatic) resection, and 4 patients chose GKS. Twenty-nine percent became seizure free in the long term, and overall a majority of patients (55%) reported at least > 90% seizure improvement. Only 3 patients were ultimately able to discontinue anticonvulsants, whereas most patients were taking an average of 2 antiepileptic drugs pre- and postoperatively. The only factor significantly correlated with seizure-free outcome was the absence of mental retardation. The HH volume, HH type, and amount of resection or disconnection were not correlated to seizure freedom. A total of 4 patients (10%) died, 2 immediately after surgery and 2 later. All of them had undergone a resection, as opposed to GKS, and still had seizures. Postoperatively, persistent neurological deficits were seen in 1 patient; 34% of patients had mild hormonal problems; and 59% experienced weight gain of at least 6.8 kg (average gain 12.7 kg).

CONCLUSIONS

Surgical or GKS procedures in adults with HH provided seizure freedom in one-third of patients. The only significant favorable prognostic factor was the absence of mental retardation. The overall mortality rate was high, at 10%. Other important morbidities were persistent hormonal disturbances and weight gain.

Endoscopic surgery for hypothalamic hamartomas causing medically refractory gelastic epilepsy

INTRODUCTION

There is increasing evidence that removal or disconnection of hypothalamic hamartomas can lead to seizure control and improvement in behavior. The purpose of this study is to report our experiences with endoscopic removal of these hamartomas.

METHODS

This is a prospective review of the early outcome of 44 patients undergoing endoscopic resection utilizing frameless stereotaxis and a micromanipulator.

RESULTS

All patients had normal-sized ventricles. Complete removal was possible in 14 patients, 13 of whom were seizure free at follow-up. Four patients suffered complications that have persisted for more than 3 months: One had significant hemiparesis and three had persistent difficulties with short-term memory. Postoperatively, no patient suffered a permanent hormonal deficiency. In one patient who had undergone a previous attempt at transcallosal resection, the procedure was abandoned because of the lack of internal anatomic landmarks. In a second patient, insufficient mass could be removed due to the size of the lesion and the distorted anatomy. Consequently, 1 week later, the patient underwent a transcallosal approach.

CONCLUSION

In appropriately selected patients, sessile hypothalamic hamartomas can be removed completely or they can be completely disconnected from the hypothalamus with an acceptable risk. At least a year after surgery is needed to evaluate the efficacy of the procedure in terms of control of seizures and improvements in behavior and emotional ability.

Gamma Knife surgery for hypothalamic hamartomas and epilepsy: patient selection and outcomes

Object

The authors present outcomes obtained in patients who underwent Gamma Knife surgery (GKS) at 1 institution as part of a multimodal treatment of refractory epilepsy caused by hypothalamic hamartomas (HHs).

Methods

Between 2003 and 2010, 19 patients with HH underwent GKS. Eight patients had follow-up for less than 1 year, and 1 patient was lost to follow-up. The 10 remaining patients (mean age 15.1 years, range 5.7–29.3 years) had a mean follow-up of 43 months (range 18–81 months) and are the focus of this report. Five patients had undergone a total of 6 prior surgeries: 1 transcallosal resection of the HH, 2 endoscopic transventricular resections of the HH, 2 temporal lobectomies, and 1 arachnoid cyst evacuation. In an institutional review board–approved study, postoperative complications and long-term outcome measures were monitored prospectively with the use of a proprietary database. Seven patients harbored Delalande Type II lesions; the remainder harbored Type III or IV lesions. Seizure frequency ranged from 1–2 monthly to as many as 100 gelastic seizures daily. The mean lesion volume was 695 mm3 (range 169–3000 mm3, median 265 mm3). The mean/median dose directed to the 50% isodose line was 18 Gy (range 16–20 Gy). The mean maximum point dose to the optic chiasm was 7.5 Gy (range 5–10 Gy). Three patients underwent additional resection 14.5, 21, and 32 months after GKS.

Results

Of the 10 patients included in this study, 6 are seizure free (2 after they underwent additional surgery), 1 has a 50%–90% reduction in seizure frequency, 2 have a 50% reduction in seizure frequency, and 1 has observed no change in seizure frequency. Overall quality of life, based on data obtained from follow-up telephone conversations and/or surveys, improved in 9 patients and was due to improvements in seizure control (9 patients), short-term memory loss (3 patients), and behavioral symptoms (5 patients); in 1 patient, quality of life remains minimally affected. Incidences of morbidity were all temporary and included poikilothermia (1 patient), increased depression (1 patient), weight gain/increased appetite (2 patients), and anxiety (1 patient) after GKS.

Conclusions

Of the approximately 150 patients at Barrow Neurological Institute who have undergone treatment for HH, the authors have reserved GKS for treatment of small HHs located distal from radiosensitive structures in patients with high cognitive function and a stable clinical picture, which allows time for the effects of radiosurgery to occur without further deterioration. The lack of significant morbidity and the clinical outcomes achieved in this study demonstrated a low risk of GKS for HH with results comparable to those of previous series.

Ketogenic diet treatment for pediatric super-refractory status epilepticus

PURPOSE

We aimed to study whether ketogenic diet (KD) therapy leads to resolution of super-refractory status epilepticus in pediatric patients without significant harm.

METHOD

A retrospective review was performed at Phoenix Children's Hospital on patients with super-refractory status epilepticus undergoing ketogenic diet therapy from 2011 to 2015.

RESULTS

Ten children with super-refractory status epilepticus, ages 2-16 years, were identified. 4/10 patients had immune mediated encephalitis, including Rasmussen encephalitis, anti-N-methyl-d-aspartate receptor encephalitis, and post-infectious mycoplasma encephalitis. Other etiologies included Lennox Gastaut Syndrome, non-ketotic hyperglycinemia, PCDH19 and GABRG2 genetic epilepsy, New Onset Refractory Status Epilepticus, and Febrile Infection-Related Epilepsy Syndrome. 4/10 patients' EEG features suggested focal with status epilepticus, and 6/10 suggested generalized with status epilepticus. Median hospital length was 61days and median ICU length was 27days. The median number of antiepileptic medications prior to diet initiation was 3.0 drugs, and the median after ketogenic diet treatment was 3.5 drugs. Median duration of status epilepticus prior to KD was 18days. 9/10 patients had resolution of super-refractory status epilepticus in a median of 7days after diet initiation. 8/9 patients were weaned off anesthesia within 15days of diet initiation, and within 1day of achieving ketonuria. 1/10 patients experienced side effects on the diet requiring supplementation.

CONCLUSION

Most patients achieved resolution of status epilepticus on KD therapy, suggesting it could be an effective therapy that can be utilized early in the treatment of children with super refractory status epilepticus.

Nonconvulsive status epilepticus in patients suffering spontaneous subarachnoid hemorrhage

OBJECT

Nonconvulsive status epilepticus (NCSE) is an underrecognized and poorly understood complication of aneurysmal subarachnoid hemorrhage (SAH). The authors evaluated the risk factors, electroencephalographic (EEG) characteristics, hospital course, and clinical outcomes associated with NCSE in a population with SAH treated at a single institution.

METHODS

The hospitalization and outcome data were reviewed in 11 patients who had received a diagnosis of NCSE and SAH. The study included individuals from a cohort of 389 consecutive patients with SAH who were treated between March 2003 and June 2005, and who were analyzed retrospectively. The patients' medical history, neurological grade, events of hospitalization, EEG morphological patterns, and disposition were analyzed. Advanced age, female sex, need for ventriculostomy, poor neurological grade (Hunt and Hess Grade III, IV, or V), thick cisternal blood clots, and structural lesions (intracerebral hemorrhage and stroke) were common in the population with NCSE. Patients with normal results on angiograms, good neurological grade (Hunt and Hess Grade I or II), and minimal SAH (Fisher Grade 1 or 2) were at lower risk. The most common ictal patterns were intermittent, and consisted of generalized periodic epileptiform discharges. Medical complications were also frequent, and the outcome of these patients was poor despite aggressive treatment regimens.

CONCLUSIONS

Nonconvulsive status epilepticus is a devastating complication of SAH with a high rate of associated morbidity. Based on these findings it appears that the patients at highest risk for NCSE can be identified, and this should provide a basis for further studies designed to determine the clinical significance of various EEG patterns and to develop preventative strategies.

Electrophysiological properties of human hypothalamic hamartomas

The hypothalamic hamartoma (HH) is a rare developmental malformation often characterized by gelastic seizures, which are usually refractory to medical therapy. The mechanisms of epileptogenesis operative in this subcortical lesion are unknown. In this study, we used standard patch-clamp electrophysiological techniques combined with histochemical approaches to study individual cells from human HH tissue immediately after surgical resection. More than 90% of dissociated HH cells were small (6-9 microm soma) and exhibited immunoreactivity to the neuronal marker NeuN, and to glutamic acid decarboxylase, but not to glial fibrillary acidic protein. Under current-clamp, whole-cell recordings in single dissociated cells or in intact HH slices demonstrated typical neuronal responses to depolarizing and hyperpolarizing current injection. In some cases, HH cells exhibited a "sag-like" membrane potential change during membrane hyperpolarization. Interestingly, most HH cells exhibited robust, spontaneous "pacemaker-like" action potential firing. Under voltage-clamp, dissociated HH cells exhibited functional tetrodotoxin (TTX)-sensitive Na(+) and tetraethylammonium-sensitive K(+) currents. Both GABA and glutamate evoked whole-cell currents, with GABA exhibiting a peak current amplitude 10-fold greater than glutamate. These findings suggest that human HH tissues, associated with gelastic seizures, contained predominantly small GABAergic inhibitory neurons that exhibited intrinsic "pacemaker-like" behavior.

Costs and quality of life of multiple sclerosis in the United Kingdom

This cost-of-illness analysis for the United Kingdom is part of a Europe-wide study on the costs of multiple sclerosis (MS). The objective was to analyze the costs and quality of life (utility) related to the level of disease severity. People with MS from a database administered by a UK charity (the MS Trust) were asked to participate in the survey by answering a postal questionnaire. In addition to details on the disease (type of disease, relapses, level of functional disability), the questionnaire asked for information on all resource consumption, medical, non-medical, work absence and informal care as well as utility. The response rate was 19%, and a total of 2048 people were included. The mean age of the cohort was 51 years, and 23% of people were > or =60 years of age. Disease severity was concentrated in people with moderately severe MS (Expanded Disability Status Scale [EDSS] score of 4 to 6.5), with 21, 60 and 19% of people reporting mild, moderate and severe disease, respectively. Costs and utility are highly correlated with disease severity. Mean annual costs for all people in the study increase from approximately pound 12.000 at an EDSS score <4 to almost pound 60.000 at an EDSS score > or =7. In particular, employment rates are reduced from 82% in early disease to 2% at an EDSS score of 8, while the costs of inpatient care, investments, informal care and productivity losses increase by more than tenfold between an EDSS score of 0-1 and a score > or =7. Utility decreases from 0.92 at an EDSS score of 0 to a state worse than death in the most severe state (-0.18 at an EDSS score of 9). Compared to the results in an earlier cost study in the United Kingdom using a comparable methodology, costs have substantially increased, by roughly 40%. Part of the increase is due to a higher use of disease-modifying drugs and, possibly linked with this, a higher use of ambulatory care and services. Another part of the increase is most likely due to an increased age in the current sample, with more patients on early retirement due to MS and more intense use of informal care. However, another reason may lie in the methodology, e.g. different unit costs or differences in the sample distribution, despite a similar mean EDSS score of 5.1.

Functional annotation of rare gene aberration drivers of pancreatic cancer

As we enter the era of precision medicine, characterization of cancer genomes will directly influence therapeutic decisions in the clinic. Here we describe a platform enabling functionalization of rare gene mutations through their high-throughput construction, molecular barcoding and delivery to cancer models for in vivo tumour driver screens. We apply these technologies to identify oncogenic drivers of pancreatic ductal adenocarcinoma (PDAC). This approach reveals oncogenic activity for rare gene aberrations in genes including NAD Kinase (NADK), which regulates NADP(H) homeostasis and cellular redox state. We further validate mutant NADK, whose expression provides gain-of-function enzymatic activity leading to a reduction in cellular reactive oxygen species and tumorigenesis, and show that depletion of wild-type NADK in PDAC cell lines attenuates cancer cell growth in vitro and in vivo. These data indicate that annotating rare aberrations can reveal important cancer signalling pathways representing additional therapeutic targets.

Respiratory syncytial virus infection and neurologic abnormalities: retrospective cohort study

Respiratory syncytial virus is a common cause of acute respiratory infection in children. Previous reports have associated respiratory syncytial virus infection and acute neurologic symptoms, including apnea and seizures. This study examined the prevalence of acute neurologic symptoms associated with respiratory syncytial virus and non-respiratory syncytial virus respiratory infections in children requiring admission to a pediatric intensive care unit. We screened all admissions over a 4-year period at a single center, identifying children between birth and 2 years of age with bronchiolitis or acute upper respiratory infection. Children with a history of prematurity, preexisting medical conditions, or prior neurologic problems were excluded. Retrospective chart review of 236 admissions was conducted, identifying the etiology of respiratory infection and the presence or absence of acute neurologic signs or symptoms. This study demonstrated a prevalence of acute neurologic signs or symptoms in 36.4% of respiratory syncytial virus-negative patients (n = 115) and 39.1% in the respiratory syncytial virus-positive group (n = 121). Apnea, the most common symptom, was observed in 19.8% of respiratory syncytial virus-positive cases and 16.5% of negative patients. Seizures were reported in 6.6% of the positive cases and in 12.2% of the negative cohort. These differences showed no statistical significance. Although neurologic signs and symptoms are common in this population of children with acute respiratory infection, there was no significant difference in the prevalence of neurologic problems between respiratory syncytial virus-positive and -negative patients.

Hypothalamic hamartoma with epilepsy: Review of endocrine comorbidity

The most common, and usually the only, endocrine disturbance in patients with hypothalamic hamartoma (HH) and epilepsy is central precocious puberty (CPP). The mechanism for CPP associated with HH may relate to ectopic generation and pulsatile release of gonadotropin-releasing hormone (GnRH) from the HH, but this remains an unproven hypothesis. Possible regulators of GnRH release that are intrinsic to HH tissue include the following: (1) glial factors (such as transforming growth factor α[TGFα) and (2) γ-aminobutyric acid (GABA)-mediated excitation. Both are known to be present in surgically-resected HH tissue, but are present in patients with and without a history of CPP, suggesting the possibility that symptoms related to HH are directly associated with the region of anatomic attachment of the HH to the hypothalamus, which determines functional network connections, rather than to differences in HH tissue expression or pathophysiology. CPP associated with HH presents with isosexual development prior to the age of 8 years in girls and 9 years in boys. It is not uncommon for CPP with HH to present in children at an earlier age in comparison to other causes of CPP, including in infancy. Surgical resection of the HH can be effective for treating CPP, but is reserved for patients with intractable epilepsy, since GnRH agonists are widely available and effective treatment. Other endocrine disturbances with HH are rare, but can include growth hormone deficiency, hypothyroidism, and adrenal insufficiency. Diabetes insipidus is commonly encountered postoperatively, but is not observed with HH prior to surgical intervention.