Acute encephalitis with refractory, repetitive partial seizures: case reports of this unusual post-encephalitic epilepsy

Seizure burden and neuropsychological outcomes of new-onset refractory status epilepticus: Systematic review

Background

Long-term sequelae of the new onset refractory status epilepticus (NORSE) include the development of epilepsy, cognitive deficits, and behavioral disturbances. The prevalence of these complications has been previously highlighted in case reports and case series: however, their full scope has not been comprehensively assessed.

Methods

We conducted a systematic review of the literature (PROSPERO ID CRD42022361142) regarding neurological and functional outcomes of NORSE at 30 days or longer following discharge from the hospital. A systematic review protocol was developed using guidance from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Results

Of the 1,602 records for unique publications, 33 reports on adults and 52 reports on children met our inclusion criteria. They contained the description of 280 adults and 587 children of whom only 75.7 and 85% of patients, respectively had data on long-term follow-up. The mean age of adult and pediatric patients was 34.3 and 7.9 years, respectively; and the longest duration of follow up were 11 and 20 years, respectively. Seizure outcomes received major attention and were highlighted for 93.4 and 96.6% of the adult and pediatric NORSE patients, respectively. Seizures remained medically refractory in 41.1% of adults and 57.7% of children, while seizure freedom was achieved in only 26 and 23.3% of these patients, respectively. The long-term cognitive outcome data was provided for just 10.4% of the adult patients. In contrast, cognitive health data were supplied for 68.9% of the described children of whom 31.9% were moderately or severely disabled. Long-term functional outcomes assessed with various standardized scales were reported in 62.2 and 25.5% of the adults and children, respectively with majority of patients not being able to return to a pre-morbid level of functioning. New onset psychiatric disorders were reported in 3.3% of adults and 11.2% of children recovering from NORSE.

Conclusion

These findings concur with previous observations that the majority of adult and pediatric patients continue to experience recurrent seizures and suffer from refractory epilepsy. Moderate to severe cognitive disability, loss of functional independence, and psychiatric disorders represent a hallmark of chronic NORSE signifying the major public health importance of this disorder.

Infection and inflammation: radiological insights into patterns of pediatric immune-mediated CNS injury

The central nervous system (CNS) undergoes constant immune surveillance enabled via regionally specialized mechanisms. These include selectively permissive barriers and modifications to interlinked innate and adaptive immune systems that detect and remove an inciting trigger. The end-points of brain injury and edema from these triggers are varied but often follow recognizable patterns due to shared underlying immune drivers. Imaging provides insights to understanding these patterns that often arise from unique interplays of infection, inflammation and genetics. We review the current updates in our understanding of these intersections and through examples of cases from our practice, highlight that infection and inflammation follow diverse yet convergent mechanisms that can challenge the CNS in children.

Guidelines for the diagnosis and treatment of acute encephalopathy in childhood

The cardinal symptom of acute encephalopathy is impairment of consciousness of acute onset during the course of an infectious disease, with duration and severity meeting defined criteria. Acute encephalopathy consists of multiple syndromes such as acute necrotizing encephalopathy, acute encephalopathy with biphasic seizures and late reduced diffusion and clinically mild encephalitis/encephalopathy with reversible splenial lesion. Among these syndromes, there are both similarities and differences. In 2016, the Japanese Society of Child Neurology published 'Guidelines for the Diagnosis and Treatment of Acute Encephalopathy in Childhood', which made recommendations and comments on the general aspects of acute encephalopathy in the first half, and on individual syndromes in the latter half. Since the guidelines were written in Japanese, this review article describes extracts from the recommendations and comments in English, in order to introduce the essence of the guidelines to international clinicians and researchers.

Neurocritical care and target immunotherapy for febrile infection-related epilepsy syndrome

Febrile infection-related epilepsy syndrome (FIRES) is an intractable neurological disease characterized by an unexplained refractory status epilepticus triggered by febrile infection. A Consensus definition of FIRES was proposed in 2018, and its clinical features and prognosis are gradually being clarified. However, the development of effective treatments has been hindered as the etiology of this rare disease is as yet unelucidated. The basic approach to the management of FIRES, like other forms of epilepsy, is based on the control of seizures, however seizures are extremely intractable and require intravenous administration of large doses of anticonvulsants, mainly barbiturates. This treatment strategy produces various complications including respiratory depression and drug hypersensitivity syndrome, which make it more difficult to control seizures. Consequently, it is crucial to predict these events and to formulate a planned treatment strategy. As well, it is important to grow out of conventional treatment strategies that rely on only anticonvulsants, and alternative therapies are gradually being developed. One such example is the adoption of a ketogenic diet which may lead to reduced convulsions as well as improve intellectual prognosis. Further, overproduction of inflammatory cytokines in the central nervous system has been shown to be strongly related to the pathology of FIRES which has led to attempts at immunomodulation therapy including anti-cytokine therapy.

The effectiveness of phenobarbital in patients with refractory status epilepticus undergoing therapeutic plasma exchange

This study aimed to elucidate the therapeutic concentration range of phenobarbital (PB) for adults, as well as the influence of therapeutic plasma exchange (TPE) on plasma concentration of PB. We retrospectively reviewed consecutive patients diagnosed with refractory status epileptic (RSE) and treated with a bolus injection of PB as well as TPE, admitted to our neurocritical care unit from November 2015 to October 2016. Continuous electroencephalographic monitoring was performed routinely for these patients. TPE was performed using a continuous-flow cell separator. PB concentrations in the plasma and cerebrospinal fluid were measured by gas chromatography-mass spectrometer analysis before and after TPE. A total of seven patients were included; among these, one patient had RSE related to anti-N-methyl-D-aspartate receptor encephalitis, another patient had Hashimoto encephalopathy, and five patients had undetermined etiology. For patients with clinical and electrographic control (n=6), the plasma concentration of PB ranged from 138 to 243.7 μg/ml. In addition, of six paired plasma samples (before and after TPE) obtained from three patients, no significant differences between the concentrations of PB were detected (P=0.6), suggesting that TPE may not significantly affect the plasma concentration of PB. This study confirmed that PB more than 100 µg/ml was effective for adults with RSE. Moreover, TPE may not have an influence on the plasma concentration of PB.Video abstract: http://links.lww.com/WNR/A489.

Combination of intravenous immunoglobulin and steroid pulse therapy improves outcomes of febrile refractory status epilepticus

BACKGROUND

Febrile infections are an important cause of paediatric refractory status epilepticus, and immune-mediated mechanisms and inflammatory processes have been associated with neurological manifestations in such patients. The aim of this study was to investigate the effects of immunotherapy as adjuvant treatment for febrile refractory status epilepticus.

METHODS

We retrospectively reviewed cases of febrile refractory status epilepticus in a paediatric intensive care unit between January 2000 and December 2013 and analysed their clinical characteristics. Patients positive for antineuronal antibodies against surface antigens were excluded.

RESULTS

We enrolled 63 patients (38 boys), aged 1-18 years, all of whom received multiple antiepileptic drugs. Twenty-nine (46%) of the patients received intravenous immunoglobulin alone, 16 (25.4%) received a combination of intravenous immunoglobulin and methylprednisolone pulse therapy, and 18 (28.6%) did not receive immunotherapy treatment. Overall, 12 (19%) patients died within 1 month. After 6 months, 12 (20%) patients had good neurological outcomes, including two who returned to baseline and 13 (29.5%) who had favourable seizure outcomes. We compared the outcomes of the different treatments, and found that a combination of intravenous immunoglobulin and methylprednisolone pulse therapy had the best neurological and seizure outcomes at 6 months compared to intravenous immunoglobulin alone and no immunotherapy.

CONCLUSIONS

Our observational study showed that a combination of intravenous immunoglobulin and methylprednisolone pulse therapy as adjuvant treatment for febrile refractory status epilepticus was associated with better neurological and seizure outcomes. Further prospective studies are needed to confirm these findings.

New-Onset Refractory Status Epilepticus with Claustrum Damage: Definition of the Clinical and Neuroimaging Features

New-onset refractory status epilepticus (NORSE) is a rare but challenging condition occurring in a previously healthy patient, often with no identifiable cause. We describe the electro-clinical features and outcomes in a group of patients with NORSE who all demonstrated a typical magnetic resonance imaging (MRI) sign characterized by bilateral lesions of the claustrum. The group includes 31 patients (12 personal and 19 previously published cases; 17 females; mean age of 25 years). Fever preceded status epilepticus (SE) in 28 patients, by a mean of 6 days. SE was refractory/super-refractory in 74% of the patients, requiring third-line agents and a median of 15 days staying in an intensive care unit. Focal motor and tonic–clonic seizures were observed in 90%, complex partial seizures in 14%, and myoclonic seizures in 14% of the cases. All patients showed T2/FLAIR hyperintense foci in bilateral claustrum, appearing on average 10 days after SE onset. Other limbic (hippocampus, insular) alterations were present in 53% of patients. Within the personal cases, extensive search for known autoantibodies was inconclusive, though 7 of 11 patients had cerebrospinal fluid lymphocytic pleocytosis and 3 cases had oligoclonal bands. Two subjects died during the acute phase, one in the chronic phase (probable sudden unexplained death in epilepsy), and one developed a persistent vegetative state. Among survivors, 80% developed drug-resistant epilepsy. Febrile illness-related SE associated with bilateral claustrum hyperintensity on MRI represents a condition with defined clinical features and a presumed but unidentified autoimmune etiology. A better characterization of de novo SE is mandatory for the search of specific etiologies.

Acute encephalitis with refractory, repetitive partial seizures: Pathological findings and a new therapeutic approach using tacrolimus

Acute encephalitis with refractory, repetitive partial seizures (AERRPS) is characterized by prolonged severe seizures and a high-grade fever. We experienced a boy with severe AERRPS with frequent partial seizures that exhibited right-side predominance. The patient required the continuous intravenous administration of many antiepileptic drugs and respirator management for several months. Methylprednisolone pulse therapy and intravenous immunoglobulin administration were only temporarily effective. The MRI and EEG showed the abnormality in the left occipital lobe. Although occipital lobectomy was performed, his seizures continued. His cerebrospinal fluid exhibited elevated protein and proinflammatory cytokine levels, and was positive for anti-glutamate receptor ε2 antibodies. Pathological examination showed infiltration of many neutrophilic leukocytes, T cells, and microglia in the area exhibiting severe spongiosis. We thought that the exaggerated microglia and T-cell responses were related to the pathogenesis of the patient's seizures, and we therefore initiated treatment with tacrolimus. As a result, many of the daily seizure clusters were ameliorated, and the patient was discharged. We attempted to discontinue the tacrolimus twice, but the patient's seizure clusters recurred each time. This is the first case report of the pathological findings of AERRPS and showing an effective therapeutic approach using tacrolimus. Tacrolimus may be an effective immunosuppressant, especially for patients with severe AERRPS.

Effect of Antiepileptic Drugs for Acute and Chronic Seizures in Children with Encephalitis

BACKGROUND

Encephalitis presents with seizures in the acute phase and increases the risk of late unprovoked seizures and epilepsy. This study aimed to evaluate the effect of antiepileptic drugs in pediatric patients with acute seizures due to encephalitis and epilepsy.

PATIENTS AND METHODS

Cases of acute pediatric encephalitis between January 2000 and December 2010 were reviewed. Clinical data, including onset at age, seizure type, seizure frequency, effects of antiepileptic drugs, and prognosis were analyzed.

RESULTS

During the study period, 1038 patients (450 girls, 588 boys) were enrolled. Among them, 44.6% (463) had seizures in the acute phase, 33% had status epilepticus, and 26% (251) developed postencephalitic epilepsy. At one year of follow-up, 205 of the 251 patients with postencephalitic epilepsy were receiving antiepileptic drugs while 18% were seizure free even after discontinuing the antiepileptic drugs. Among those with postencephalitic epilepsy, 67% had favorable outcomes and were using <2 anti-epileptic drugs while 15% had intractable seizures and were using ≥ 2 antiepileptic drugs. After benzodiazepines, intravenous phenobarbital was preferred over phenytoin as treatment of postencephalitic seizures in the acute phase. For refractory status epilepticus, high-dose topiramate combined with intravenous high-dose phenobarbital or high-dose lidocaine had less side effects.

CONCLUSIONS

Children with encephalitis have a high rate of postencephalitic epilepsy. Phenobarbital and clonazepam are the most common drugs used, alone or in combination, for postencephalitic epilepsy.

Claustrum damage and refractory status epilepticus following febrile illness

OBJECTIVE

To characterize the clinical, EEG, and brain imaging findings in an adult case series of patients with de novo refractory status epilepticus (SE) occurring after a febrile illness.

METHODS

A retrospective study (2010-2013) was undertaken with the following inclusion criteria: (1) previously healthy adults with refractory SE; (2) seizure onset 0-21 days after a febrile illness; (3) lacking evidence of infectious agents in CSF; (4) no history of seizures (febrile or afebrile) or previous or concomitant neurologic disorder.

RESULTS

Among 155 refractory SE cases observed in the study period, 6 patients (17-35 years old) fulfilled the inclusion criteria. Confusion and stupor were the most common symptoms at disease onset, followed after a few days by acute repeated seizures that were uncountable in all but one. Seizures consisted of focal motor/myoclonic phenomena with subsequent generalization. Antiepileptic drugs failed in every patient to control seizures, with all participants requiring intensive care unit admission. Barbiturate coma with burst-suppression pattern was applied in 4 out of 6 patients for 5-14 days. One participant died in the acute phase. In each patient, we observed a reversible bilateral claustrum MRI hyperintensity on T2-weighted sequences, without restricted diffusion, time-related with SE. All patients had negative multiple neural antibodies testing. Four out of 5 surviving patients developed chronic epilepsy.

CONCLUSIONS

This is a hypothesis-generating study of a preliminary nature supporting the role of the claustrum in postfebrile de novo SE; future prospective studies are needed to delineate the specificity of this condition, its pathogenesis, and the etiology.

Super-Refractory Status Epilepticus: Report of a Case and Review of the Literature

Super-refractory status epilepticus (SE; ie, SE continuing or recurring despite 24 hours of general anesthesia) is a severe condition with high percentage of mortality and morbidity. Usually, this condition occurs because of serious brain damage; nevertheless, some patients develop super-refractory SE without identifiable etiology. Although not uncommonly encountered in neurointensive care, scientific data on this condition are still lacking in terms of treatment and prognosis. Herein, we report a case of super-refractory SE with recovery after 50 days, despite electroencephalographic (EEG) and magnetic resonance imaging (MRI) signs traditionally related to poor prognosis. A review of the literature on super-refractory SE is also presented.

Super-refractory status epilepticus in West China

OBJECTIVE

This study aims to determine the general frequency, mortality, and risk factors of super-refractory status epilepticus (SRSE) versus non-refractory status epilepticus (NRSE) and refractory status epilepticus (RSE).

METHODS

This work is a retrospective study. Clinical data of patients who were diagnosed with status epilepticus (SE) in the neurological ward and neuro-intensive care unit of West China Hospital from January 2009 to December 2012 were collected and analyzed.

RESULTS

A total of 98 patients were included in the study. The percentages of NRSE, RSE, and SRSE were 67.3%, 20.4%, and 12.2%, respectively. Convulsive SE was the main seizure type among the three groups. The most common cause of NRSE was related to epilepsy (EP). However, 67.7% of SRSE cases were caused by acute encephalitis. Moreover, 47% of SE and 40% of RSE cases had a history of EP, whereas only 8.3% of SRSE cases had such history (P < 0.01). The percentage of patients with STESS ≤2 was lowest in the SRSE group without statistical significance (P > 0.05). The general mortality of SE was 7.1%, whereas that of SRSE was 50%. During follow-up, most SRSE patients who survived have developed symptomatic EP.

CONCLUSIONS

This study was the first to use the statistical percentage of SRSE. Approximately 12.2% of SE cases will result in SRSE, which is a challenging medical situation for doctors. Patients with first episodes and acute encephalitis were also prone to develop SRSE.

Effect of levetiracetam in acute encephalitis with refractory, repetitive partial seizures during acute and chronic phase

AIM

To clarify the effect of levetiracetam (LEV) for acute and chronic seizure control in acute encephalitis with refractory, repetitive partial seizures (AERRPS).

METHODS

We retrospectively reviewed the clinical course of six AERRPS cases treated with LEV, and explored the acute phase termination by withdrawal from barbiturate-induced coma under artificial ventilation, and the reduction in seizure frequency during the chronic phase. LEV was administrated orally or via nasogastric tubes as an add-on agent during acute (n=3; age 8-10 years) and chronic (n=3; age 19-30 years) AERRPS.

RESULTS

In the acute phase, administration of LEV (50-60 mg/kg/d) in combination with phenobarbital (n=3; peak 57.9-76.1 μg/ml) and potassium bromide (n=2; 30-36 mg/kg/d)) resulted in successful reduction of intravenous barbiturate dosage and withdrawal from artificial ventilation. In the chronic phase, seizure frequency reduced by >75% for 5-18 months with LEV 750-1500 mg/d.

CONCLUSION

LEV may affect seizure control in AERRPS, particularly during the chronic phase, through its unique action of inhibition of excitatory neurotransmitter release. The regimen of oral barbiturate, potassium bromide and LEV would be worth for trial during the acute phase of AERRPS.

Status epilepticus: immunologic and inflammatory mechanisms

Status epilepticus (SE) can be difficult to treat, particularly if refractory, and lead to significant morbidity and mortality. Prolonged seizures are also a risk factor for the subsequent diagnosis of epilepsy. Activation of the immune system and inflammation are areas of recent interest in the field of epilepsy, and there is growing evidence that these may be involved in the pathogenesis of ongoing SE and subsequent epileptogenesis. We review the current data on this topic in both animal models and human disease. We conclude that there is evidence suggesting a role for immunologic and inflammatory mechanisms in SE. Further research, especially human studies, is necessary to determine whether targeting the immune system would improve control of SE and prevent sequelae such as epileptogenesis.

Ketogenic diet therapy is effective in encephalitis with refractory seizures

OBJECTIVE AND IMPORTANCE

Although ketogenic diet therapy is effective in refractory seizures in childhood, its effect on adult encephalitis with similar refractory seizures and prolonged encephalopathy has not been well reported.

CLINICAL PRESENTATION

We report here a case of a 22-year-old man with acute encephalitis with refractory repetitive partial seizures (AERRPS).

INTERVENTION

Partial seizures of the face developed to repeated generalized convulsions, which were refractory against anti-epileptic drugs and a high dose of propofol. After struggling for 9 months, he dramatically recovered after ketogenic diet therapy.

CONCLUSION

Ketogenic diet therapy may be an important tool to help cure AERRPS.

Problems and controversies in status epilepticus: a review and recommendations

Status epilepticus (SE) is a neurologic emergency that require immediate vigorous treatment in order to prevent serious morbidity or even death. Several investigators have suggested that the underlying etiology is the primary determinant of outcome. We believe that this may be true in aggressively treated SE, but not when the treatment is less than optimal. In this article, we will discuss the factors that have been implicated in affecting SE outcomes, and argue, on the basis of both human and experimental animal data, that aggressive treatment is necessary and appropriate for all presentations of SE in order to maximize the probability of a successful outcome even when the etiology suggests a poor prognosis.

Anti-N-methyl-d-aspartate receptor encephalitis

Anti-N-methyl-d-aspartate (NMDA) receptor encephalitis is a treatment-responsive encephalitis associated with anti-NMDA receptor antibodies, which bind to the NR1/NR2 heteromers of the NMDA receptors. It is a highly characteristic syndrome evolving in five stages: the prodromal phase (viral infection-like symptoms), psychotic phase, unresponsive phase, hyperkinetic phase, and gradual recovery phase. It has been considered as a paraneoplastic syndrome usually affecting childbearing-age female with ovarian tumors; however, recent reports suggest a much higher incidence of nonparaneoplastic cases in children. We report a 14-year-old girl with anti-NMDA receptor encephalitis without a detectable tumor who showed a nearly complete recovery after intensive immunotherapy.

A Boy with Non-Herpes Simplex Acute Limbic Encephalitis and Antiglutamate Receptor Antibodies

This report concerns a 12-year-old male with intractable seizures over a long period. The case fulfilled the diagnostic criteria for nonherpetic acute limbic encephalitis. He had frequent convulsions starting with a partial seizure at the left angle of the mouth and progressing to secondary generalized seizures. He was treated with several anticonvulsants, combined with methylprednisolone and γ-globulin under mechanical ventilation. However, his convulsions reappeared after tapering of the barbiturate. His magnetic resonance imaging showed a high intensity area in the hippocampus by FLAIR and diffusion. After five months he recovered without serious sequelae. Virological studies, including for herpes simplex virus, were all negative. He was transiently positive for antiglutamate receptor antibodies in cerebrospinal fluid and serum.

Amplitude-integrated electroencephalography in patients with acute encephalopathy with refractory, repetitive partial seizures

We report amplitude-integrated EEG findings in two children with acute encephalopathy with refractory, repetitive partial seizures. Both patients had a febrile illness one week before the onset of seizure. They had reduction of consciousness and repetitive seizures refractory to first-line antiepileptic drugs. Seizure frequency rapidly increased and evolved into status epilepticus. Continuous seizure monitoring with amplitude-integrated EEG revealed frequent subclinical seizures which were missed by direct observation. In addition, the site of origin of seizures was multifocal, and seizure foci shifted from one hemisphere to the other. Their seizures were controlled after an administration of high-dose phenobarbital. Continuous seizure monitoring with amplitude-integrated EEG will contribute to correct estimation of seizure burden and efficacy of antiepileptic drugs in children with acute encephalopathy with refractory, repetitive partial seizures.

Acute encephalitis with refractory, repetitive partial seizures (AERRPS): a peculiar form of childhood encephalitis

OBJECTIVE

We conducted a nationwide multicenter study in Japan to elucidate the clinical and laboratory characteristics of acute encephalitis with refractory, repetitive partial seizures (AERRPS).

MATERIALS AND METHODS

Clinical and laboratory features, treatment, and outcome were assessed using a structured questionnaire.

RESULTS

Twenty-nine children were enrolled in the study. Refractory and repetitive partial seizures accompanied by fever were the cardinal clinical features. Partial seizures consisted principally of eye deviation or facial twitching, being periodically repeated during the acute phase. These seizures were refractory to conventional anticonvulsants and were only suppressed by high-dose intravenous barbiturate administration. Rhythmic activities on electroencephalography and non-specific cerebral atrophy on neuroimaging were common. Serum or cerebrospinal antibodies against GluRepsilon2 were positive in six patients. General prognosis was unfavorable due to intractable epilepsy and cognitive deficits.

CONCLUSION

Based on the peculiar and homogenous features, AERRPS can be regarded as a distinct clinical entity.

Epileptic encephalopathy in children possibly related to immune-mediated pathogenesis

Severe epilepsy in the paediatric population negatively influences neurological and cognitive development. Different etiological factors could be responsible of these severe epilepsies, and an early diagnosis could change, in some cases, the neurological and cognitive development. Immune mechanisms have been reported in epilepsy. Epilepsy has been associated with systemic lupus erythematosus, with the presence of anti-phospholipid antibodies (aPL), anti-cardiolipin antibodies, anti-nuclear antibodies, Beta2-glycoprotein antibodies, and anti-glutamic acid decarboxylase (anti-GAD) antibodies. CNS inflammation and markers of adaptive immunity have been, also, associated with some epileptic syndromes, such as West syndrome, temporal lobe epilepsy, febrile seizures, tonic-clonic seizures, and tuberous sclerosis. Inflammation and blood-brain barrier (BBB) disruption could be one of the mechanisms responsible for seizure recurrence. Recently clinical entities, characterized by severe epilepsy with a febrile, acute or sub-acute onset, sometimes associated with status epilepticus, followed by drug-resistant, partial epilepsy have been described. Some of these publications also suggested acronyms for the condition described: Acute Encephalitis with Refractory, Repetitive Partial Seizures (AERRPS) reported by Japanese authors, Devastating Epileptic Encephalopathy in School-aged Children (DESC) reported by French authors. Among children with acquired symptomatic severe epilepsy, we identified a group of previously normal children who had developed severe partial epilepsy after an acute/sub-acute illness resembling encephalitis. The etiological factors for those patients seems to remain unknown, and a possible immune-mediating or inflammatory process as pathogenesis of the disease could be hypothesized. More studies need to be addressed to finally define this peculiar epileptic entity.

Effect of topiramate, in combination with lidocaine, and phenobarbital, in acute encephalitis with refractory repetitive partial seizures

OBJECTIVE

Acute encephalitis with refractory repetitive partial seizure (AERRPS) is a peculiar type of post-encephalitic/encephalopathic epilepsy. Here we report an analysis of AERRPS in a series of children and propose an effective treatment option for seizure control in these children.

METHODS

We retrospectively reviewed cases of AERRPS treated in a pediatric intensive care unit, between February 2002 and June 2006. Clinical characteristics were systemically assessed. Burst suppression coma was induced by high-dose suppressive therapy; 24-h electroencephalogram (EEG) monitoring was performed on each patient. The goal of treatment was to achieve complete clinical seizure control or burst-suppression pattern on EEG, aiming for an interburst interval of >5s. Brain imaging was done for each patient.

RESULTS

There were nine patients (seven boys), aged 5-15 years. Clinical symptoms included fever (100%), upper respiratory symptoms (66.7%) and altered consciousness (66.7%). All patients received multiple high-dose suppressive drugs and were intubated with/without inotropic agents. Seizures in three patients were stopped after high-dose lidocaine infusion (6-8 mg/kg/h) in the acute stage and three patients were stopped after high dose phenobarbital (serum level 60-80 ug/mL) combined with high-dose oral topiramate (15-20 mg/kg/day). Follow-up for this study was 16-61 months. Two subjects died while seven developed epilepsy and/or neurologic deficits; none returned to baseline. All survivors were discharged and continued multiple antiepileptic medications.

CONCLUSIONS

Our data indicates that children with AERRPS have high mortality and morbidity rates. High-dose topiramate combined with high-dose lidocaine infusion or high-dose phenobarbital in the acute stage might be an effective treatment option for children with AERRPS.

Acute encephalitis with refractory, repetitive partial seizures

Acute encephalitis with refractory, repetitive partial seizures (AERRPS) represents a peculiar form of encephalitis mainly affecting children. They usually present abruptly with seizure or impaired consciousness as well as high-grade fever following antecedent infection. Seizures in AERRPS are almost exclusively of localized origin, whose semiology includes eye deviation, hemifacial twitching, hemiclonic convulsion, and autonomic manifestations. Partial seizures are brief, but repeat with increasing frequency and develop status epilepticus at nadir. They are extremely pharmaco-resistant and are only suppressed by intravenous administration of high-dose barbiturates. Although acute seizures are hardly controlled, patients gradually recover with decreasing seizure frequency and continuously evolve into post-encephalitic epilepsy without latent period. Residual cognitive impairment is common. Electroencephalograms in active stage demonstrate electrical seizure activities and interictal periodic discharges. Magnetic resonance imaging reveals late cerebral atrophy with limited signal abnormality. Persistent fever during active stage, cerebrospinal fluid (CSF) pleocytosis, and up-regulation of neopterin raise the hypothesis that inflammatory process is involved in this condition. Furthermore, early production of autoantibody against NMDA receptor 2B in serum and CSF, although its disease specificity is still in controversy, is suggestive of autoimmune etiology. Exploration for definite clinical marker is currently in progress.

Acute encephalitis with refractory, repetitive partial seizures

BACKGROUND

Acute encephalitis with refractory, repetitive partial seizures (AERRPS) is a new epileptic syndrome described by Sakuma in Japan in 2001. The clinical manifestations, neuroimaging findings and outcome of AERRPS in Taiwan have not been reported.

METHODS

From 2000 to 2006, we collected cases that fulfilled the diagnostic criteria of AERRPS and analyzed the clinical course, virology, medication, electroencephalographic findings, neuroimaging characters and prognosis retrospectively.

RESULTS

Fourteen children aged from 1 year and 2 months to 15 years and 6 months were enrolled. They presented with prodromic symptoms including fever (n=13, 92.9%), upper respiratory tract infection symptoms (n=12, 85.7%) and gastrointestinal tract discomfort (n=6, 42.9%). Seizures occurred 3-14 days after antecedent symptoms with patterns of generalized tonic-clonic seizures, focal seizures or myoclonic seizures. The seizures were refractory to combinations of antiepileptic drugs (AEDs). Prolonged fever (n=14, 100.0%), hypersensitivity to AEDs (n=11, 78.6%) and liver function impairment (n=8, 57.1%) were noted during the period of hospitalization. The follow-up EEG findings were similar to those of initial findings including epileptiform discharges and/or generalized background slow waves. Initial brain MRI scans were normal but later showed focal or multifocal abnormal signal intensity followed by generalized brain atrophy in more than 50% of cases. The general prognosis was poor with variable psychomotor retardation and persistence of refractory epileptic seizures.

CONCLUSIONS

The similarities of the clinical features support AERRPS as a new epileptic syndrome. More study is needed to specify the etiology of the syndrome as the first step for more effective treatment.

Refractory epilepsy accompanying acute encephalitis with multifocal cortical lesions: possible autoimmune etiology

We report on a 14-year-old male suffering from acute encephalitis, whose clinical course met the criteria for acute encephalopathy with refractory, repetitive partial seizures (AERRPS). He presented with extremely refractory partial and secondary generalized seizures, and required high-dose barbiturate infusion therapy for 57 days under mechanical ventilation. Seven weeks after onset, the seizures were ameliorated by treatment with sodium bromide, carbamazepine, clobazam, and high-dose phenobarbital. Magnetic resonance imaging on day 14 of admission showed multifocal cortical lesions scattered in the bilateral hemispheres; these disappeared on day 34. Diffuse and mild atrophy of the cerebral cortex, and moderate atrophy of the hippocampus, appeared by day 61. Serum anti-glutamate receptor epsilon2 autoantibodies were detected on day 2. The patient was discharged after 113 days of admission with intractable epilepsy, memory disability, and regression of intelligence. We discuss the etiological significance of the multifocal lesions, which are unusual findings on neuroimaging of AERRPS.

Risk factors for postencephalitic epilepsy in children: a hospital-based study in Taiwan

To identify clinical, neurophysiological and neuroradiological features in acute encephalitis with predictive value for postencephalitic epilepsy (PEE) in children, a retrospective cohort study by following up 0-17-year-old children with the diagnosis of acute encephalitis was done. Total 330 children were enrolled. Of these, 54 (16.4%) developed epilepsy with a mean follow-up period of 6+/-4.6 years, and 79.6% had the diagnosis of epilepsy within six months after encephalitis. Significant risk factors for PEE include the presence of recurrent seizures, status epilepticus, severe disturbance of consciousness, the existence of focal neurological sign, and the presence of neurological deterioration during hospitalization. Patients with abnormal electroencephalogram, including focal (P<0.05), or profound cerebral dysfunction (P<0.001), and focal cortical abnormalities in neuroimaging (P<0.01), also have higher incidence of epilepsy. Furthermore, children with refractory status epilepticus at presentation also significantly increased the possibility of intractable PEE (P<0.01). We concluded that PEE is not a rare complication of acute encephalitis. Children with refractory status epilepticus or poor control of seizures are more likely to have intractable PEE.