Nandini Mullatti

Is it worth pursuing surgery for epilepsy in patients with normal neuroimaging

Objective: To determine whether it is worth pursuing surgery for the treatment of epilepsy in patients with normal neuroimaging. Methods: Two patient populations were studied: (1) 136 consecutive patients who were surgically treated; (2) 105 consecutive patients assessed with chronically implanted intracranial electrodes within the same period. Sixty patients belonged to both groups, and included all 21 patients who had normal neuroimaging. Results: There were no differences in the proportion of patients with favourable outcome between those with normal and those with abnormal neuroimaging, irrespective of whether intracranial recordings were required. Among the 19 operated patients with normal neuroimaging, 74% had a favourable outcome (Engel’s seizure outcome grades I and II), and among the 93 patients with abnormal neuroimaging, 73% had favourable outcome (p = 0.96). In patients with temporal resections, 92% of the 13 patients with normal neuroimaging had a favourable outcome, whereas among the 70 patients with abnormal neuroimaging, 80% had a favourable outcome (p = 0.44). In patients with extratemporal resections, two of the six patients with normal neuroimaging had a favourable outcome, while 12 of the 23 patients with abnormal neuroimaging had a favourable outcome (p = 0.65). Among the 105 patients studied with intracranial electrodes, five suffered transitory deficits as a result of implantation, and two suffered permanent deficits (one hemiplegia caused by haematoma and one mild dysphasia resulting from haemorrhage). Conclusions: It is worth pursuing surgery in patients with normal neuroimaging because it results in good seizure control and the incidence of permanent deficits associated with intracranial studies is low.

The Clinical Spectrum of Epilepsy in Children and Adults with Hypothalamic Hamartoma

Summary:  Purpose: Hamartomas of the hypothalamus (HH) cause an uncommon and unusual epilepsy syndrome. The condition is recognized to affect children, but the presentation in adults is not well understood. We present 19 children and adult patients with HH, including three patients whose epilepsy began in adult life. The patterns of clinical presentation, evolution of the epilepsy from childhood to adult life, and electroclinical diagnostic features are presented.

A prospective, multicenter study of cardiac-based seizure detection to activate vagus nerve stimulation.

PURPOSE This study investigates the performance of a cardiac-based seizure detection algorithm (CBSDA) that automatically triggers VNS (NCT01325623). METHODS Thirty-one patients with drug resistant epilepsy were evaluated in an epilepsy monitoring unit (EMU) to assess algorithm performance and near-term clinical benefit. Long-term efficacy and safety were evaluated with combined open and closed-loop VNS. RESULTS Sixty-six seizures (n=16 patients) were available from the EMU for analysis. In 37 seizures (n=14 patients) a ≥ 20% heart rate increase was found and 11 (n=5 patients) were associated with ictal tachycardia (iTC, 55% or 35 bpm heart rate increase, minimum of 100 bpm). Multiple CBSDA settings achieved a sensitivity of ≥ 80%. False positives ranged from 0.5 to 7.2/h. 27/66 seizures were stimulated within ± 2 min of seizure onset. In 10/17 of these seizures, where triggered VNS overlapped with ongoing seizure activity, seizure activity stopped during stimulation. Physician-scored seizure severity (NHS3-scale) showed significant improvement for complex partial seizures (CPS) at EMU discharge and through 12 months (p<0.05). Patient-scored seizure severity (total SSQ score) showed significant improvement at 3 and 6 months. Quality of life (total QOLIE-31-P score) showed significant improvement at 12 months. The responder rate (≥ 50% reduction in seizure frequency) at 12 months was 29.6% (n=8/27). Safety profiles were comparable to prior VNS trials. CONCLUSIONS The investigated CBSDA has a high sensitivity and an acceptable specificity for triggering VNS. Despite the moderate effects on seizure frequency, combined open- and closed-loop VNS may provide valuable improvements in seizure severity and QOL in refractory epilepsy patients.

Centromedian thalamic nuclei deep brain stimulation in refractory status epilepticus

BACKGROUND Refractory status epilepticus (RSE) is associated with high mortality. We report a potential treatment alternative. HYPOTHESIS Deep brain stimulation (DBS) of the centromedian thalamic nuclei (CMN) can be effective in the treatment of RSE. METHODS Report of the evolution of RSE after DBS of the CMN in a 27-year-old man. RESULTS In the course of an encephalopathy of unknown origin, and after a cardiac arrest, the patient developed RSE with myoclonic jerks and generalized tonic-clonic seizures. The EEG showed continuous generalized periodic epileptiform discharges (GPEDS). Five weeks after RSE onset, bilateral DBS of the CMN was started. This treatment was immediately followed by disappearance of tonic-clonic seizures and GPEDS, suggesting a resolution of RSE. The patient continued having multifocal myoclonic jerks, probably subcortical in origin, which resolved after 4 weeks. The patient remained clinically stable for 2 months in a persistent vegetative state. CONCLUSIONS The remission of RSE, the abolition of GPEDS, and the patient survival suggest that DBS of the CMN may be efficacious in the treatment of refractory, generalized status epilepticus.

Diffuse form of dysembryoplastic neuroepithelial tumour: the histological and immunohistochemical features of a distinct entity showing transition to dysembryoplastic neuroepithelial tumour and ganglioglioma

I. Bodi, R. Selway, P. Bannister, L. Doey, N. Mullatti, R. Elwes and M. Honavar (2012) Neuropathology and Applied Neurobiology38, 411–425

Prognostic value of intracranial seizure onset patterns for surgical outcome of the treatment of epilepsy

OBJECTIVE To investigate if intracranial EEG patterns at seizure onset can predict surgical outcome. METHODS Ictal onset patterns from intracranial EEG were analysed in 373 electro-clinical seizures and subclinical seizures from 69 patients. Seizure onset patterns were classified as: (a) Diffuse electrodecremental (DEE); (b) Focal fast activity (FA); (c) Simultaneous onset of fast activity and diffuse electrodecremental event (FA-DEE); (d) Spikes; (e) Spike-wave activity; (f) Sharp waves; (g) Alpha activity; (h) Delta activity. Presence of preceding epileptiform discharge (PED) was also studied. Engel and ILAE surgical outcome scales were used. RESULTS The mean follow-up period was 42.1 months (SD=30.1). Fast activity was the most common seizure onset pattern seen (33%), followed by (FA-DEE) (20%), DEE (19%), spike-wave activity (12%), sharp-waves (6%), alpha activity (6%), delta activity (3%) and spikes (1%). Preceding epileptiform discharges were present in 75% of patients. FA was associated with favourable outcome (p=0.0083) whereas DEE was associated with poor outcome (p=0.0025). A widespread PED was not associated with poor outcome (p=0.9559). There was no clear association between seizure onset pattern and specific pathology, except possibly between sharp/spike waves and mesial temporal sclerosis. CONCLUSIONS FA activity is associated with favourable outcome. DEE at onset was associated with poor surgical outcome. Widespread/bilateral PEDs were not associated with poor or good outcome. SIGNIFICANCE FA appears to be the best marker for the epileptogenic zone. Surgery should be contemplated with caution if DEE is the first ictal change. However, a widespread/bilateral PED at onset is common and should not discourage surgery.

Cingulate epileptogenesis in hypothalamic hamartoma

Hypothalamic hamartoma (HH) is a relatively rare cause of epilepsy, mainly affecting children. Nearly all patients develop gelastic seizures, often followed by other focal seizure types. Our case illustrates the mechanisms of epileptogenesis in HH. The patient developed gelastic attacks as a baby, and secondarily generalized seizures and drop attacks at 9 years of age. Magnetic resonance imaging (MRI) confirmed the presence of a HH. Presurgical assessment with intracranial electroencephalography (EEG) monitoring recorded gelastic seizures with generalized epileptiform activity. Functional stimulation of the hamartoma provoked gelastic attacks. Single pulse electrical stimulation (SPES) was used to identify epileptogenic cortex. SPES of the left cingular cortex provoked generalized responses similar to the spontaneous generalized discharges. Our results suggest that long‐standing history of epilepsy in patients with HH may be related to additional sources of epileptogenic activity. Electrical stimulation performed in this patient provided additional data to favor the hypothesis of secondarily epileptogenesis in the cingulate gyrus independently from the primary origin in the HH.

The histopathology of polymicrogyria: a series of 71 brain autopsy studies

Polymicrogyria (PMG) is one of the most common forms of cortical malformation yet the mechanism of its development remains unknown. This study describes the histopathological aspects of PMG in a large series including a significant proportion of fetal cases.

Pregabalin as adjunctive therapy for partial epilepsy: An audit study in 96 patients from the South East of England

INTRODUCTION Pregabalin (PGB) was licensed in the EU in 2004 as an adjunctive therapy in partial epilepsy. It is also licensed for neuropathic pain and generalised anxiety. AIMS To identify the clinical usefulness and side effects of add-on PGB in out-patient epilepsy clinics. METHODS We performed an audit on 96 consecutive patients (44 male) prescribed PGB for refractory epilepsy. Mean follow-up, for those who remained on PGB, was 23 months (range 12-39 months). RESULTS Fifty patients remained on PGB, 37 of whom reported clear improvement in seizure frequency. Among these 37 patients, 1 was seizure free for 15 months; 29 had a seizure reduction of >50%; and 7 improved by <50%. Eight patients reported a decrease in seizure severity without change in seizure frequency. Nine patients reported an incidental improvement in anxiety. Side effects were reported by 25 patients out of the 50 patients still on treatment: 12 reported drowsiness or tiredness, 8 weight gain, 7 dizziness, 2 headache, 2 cognitive side effects, 1 irritability, 1 itchiness, 1 anxiety, and 1 transient rash. Among the 46 patients who discontinued treatment, 9 had worsening of seizure frequency, 27 lack of efficacy and 9 intolerable side effects necessitating withdrawal (4 dizziness or drowsiness, 2 weight gain, 1 peripheral oedema, 1 pain in arms and legs, 1 irritability and cognitive side effects). One patient had a seizure related death (probably drowning) within 1 month of starting PGB. CONCLUSION Pregabalin seems to be an effective and well-tolerated anti-epileptic drug when used as add-on treatment in patients with refractory partial epilepsy.

Adult onset Rasmussen’s encephalitis associated with reflex language induced seizures responsive to Rituximab therapy

Rasmussen’s encephalitis (RE) is a rare, focal and progressive inflammatory disorder of unknown aetiology, resulting in unilateral hemispheric atrophy, contralateral hemiparesis and hemianopia, dysphasia with language-dominant hemispheric involvement and intractable epilepsy. RE is associated with polymorphic seizure types including epilepsia partialis continua (EPC) [1]. Current treatment strategies principally involve the combined use of corticosteroids, intravenous immunoglobulin (IVIG) and in adults, plasma exchange (PEX) although the response is variable and may be short-lived. Other treatments with greater efficacy and the potential to alter the natural history of RE are needed. Rituximab, a chimeric monoclonal antibody against CD20, has shown promise in RE although reports of its use in this disorder are few. Here, we present an unusual case of language-induced reflex seizures occurring in the context of adult-onset Rasmussen’s encephalitis and report on the clinical response to immunomodulation and the efficacy of Rituximab.