Type 1 diabetes mellitus and epilepsia partialis continua in a 6-year-old boy with elevated anti-GAD65 antibodies

Successfully treated anti-GAD limbic encephalitis in a 15-year-old diabetic boy with intravenous immunoglobulin: case report

Introduction and importance

Limbic encephalitides (LE) have symptoms and signs of new-onset seizures accompanied by cognitive impairment and signal changes in the MRI of the limbic system in the brain. Numerous antibodies against the neurons and synapses have been detected so far. Of those, antiglutamic acid decarboxylase antibody (Anti-GAD Ab) impairs the gamma amino butyric acid, one of the primary mediators that naturally prevents abnormal neuronal activity causing seizure.

Case presentation

The authors have reported a case of anti-GAD Ab LE in a diabetic male adolescent who responded dramatically to intravenous immunoglobulin and reviewed all similar pediatric cases for 15 years now.

Clinical discussion

The symptoms in children suffering from anti-GAD LE in three categories, systemic, psychiatric, and neurological, are heterogeneous. The most common manifestations were seizures followed by altered mental status and behavioral changes, respectively. The two main clinical scenarios described in GAD65-mediated autoimmune epilepsy are (1) an acute/subacute onset of seizures alone or seizures (including new-onset refractory status epilepticus, NORSE) accompanied by some degrees of cognitive and psychiatric manifestations, including amnesia and mesiotemporal inflammatory involvement consistent with LE and (2) epilepsy without clinical or MRI evidence of active central nervous system inflammation.

Conclusion

Although rare, the neurologist should consider the potential role of anti-GAD ab-associated encephalitis in the presence of diabetes mellitus.

A case report of anti-GAD65 antibody-positive autoimmune encephalitis in children associated with autoimmune polyendocrine syndrome type-II and literature review

Background

Glutamic acid decarboxylase (GAD) is the rate-limiting enzyme for the synthesis of gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. Antibodies against glutamic acid decarboxylase (GAD) are associated with various neurologic conditions described in patients, including stiff person syndrome, cerebellar ataxia, refractory epilepsy, and limbic and extra limbic encephalitis. While there are few case reports and research on anti-GAD65 antibody-associated encephalitis in adults, such cases are extremely rare in pediatric cases.

Methods

For the first time, we report a case of anti-GAD65-positive autoimmune encephalitis associated with autoimmune polyendocrine syndrome (APS) type II. We reviewed previously published pediatric cases of anti-GAD65 autoimmune encephalitis to discuss their clinical features, laboratory tests, imaging findings, EEG patterns, and prognosis.

Case presentation

An 8-year-old, male child presented to the outpatient department after experiencing generalized convulsions for twenty days. The child was admitted for epilepsy and had received oral sodium valproate (500 mg/day) in another center, where investigations such as USG abdomen and MRI brain revealed no abnormalities, however, had abnormal EEG with diffuse mixed activity in the left anterior middle prefrontal temporal region. On the follow-up day, a repeat blood test showed a very low serum drug concentration of sodium valproate hence the dose was increased to 750 mg/day. Then, the child experienced adverse effects including increased sleep, thirst, and poor appetite, prompting the parents to discontinue the medication. A repeat MRI showed increased signals on FLAIR sequences in the right hippocampus hence admitted for further management. The child's past history included a diagnosis of hypothyroidism at the age of 4, and receiving levothyroxine 75 mcg once daily. His parents are healthy with no history of any similar neurological, autoimmune, or genetic diseases, but his uncle had a history of epilepsy. At presentation, he had uncontrolled blood glucose levels with elevated HbA1c levels. Additionally, the serum and CSF autoantibodies were positive against the anti-GAD65 antibody with the titer of 1:100 and 1:32 respectively. The patient was managed with a mixed type of insulin regimen and received first-line immunotherapy (intravenous immunoglobulin, IVIG) for five consecutive days, followed by oral prednisone and sodium valproate as an antiepileptic drug. Upon achieving a favorable clinical outcome, the patient was discharged with oral medications.

Results

Among the 15 pediatric patients reported in this literature, nine presented with limbic encephalitis (LE), three with extralimbic encephalitis (ELE), and three with a combination of limbic and extralimbic encephalitis. Most of these cases exhibited T2-W FLAIR hyperintensities primarily localized to the temporal lobes in the early phase, progressing to hippocampal sclerosis/atrophy in the later phase on MRI. EEG commonly showed slow or spike waves on frontotemporal lobes with epileptic discharges. Prognostic factors varied among patients, with some experiencing persistent refractory seizures, type-1 diabetes mellitus (T1DM), persistent memory impairment, persistent disability requiring full assistance, and, in severe cases, death.

Conclusion

Our findings suggest that anti-GAD65 antibody-positive autoimmune encephalitis patients may concurrently present with other APS. Our unique case presented with multiple endocrine syndromes and represents the first reported occurrence in children. Early diagnosis and timely initiation of immunotherapy are crucial for improving clinical symptoms and reducing the likelihood of relapses or permanent disabilities. Therefore, emphasis should be placed on prompt diagnosis and appropriate treatment implementation to achieve better patient outcomes.

Glycaemic Imbalances in Seizures and Epilepsy of Paediatric Age: A Literature Review

Cerebral excitability and systemic metabolic balance are closely interconnected. Energy supply to neurons depends critically on glucose, whose fluctuations can promote immediate hyperexcitability resulting in acute symptomatic seizures. On the other hand, chronic disorders of sugar metabolism (e.g., diabetes mellitus) are often associated with long-term epilepsy. In this paper, we aim to review the existing knowledge on the association between acute and chronic glycaemic imbalances (hyper- and hypoglycaemia) with seizures and epilepsy, especially in the developing brain, focusing on clinical and instrumental features in order to optimize the care of children and adolescents and prevent the development of chronic neurological conditions in young patients.

Stiff Person Syndrome and Encephalitis with GAD Antibodies with Severe Anterograde Amnesia in an Adolescent: A Case Study and Literature Review

Antiglutamic acid decarboxylase (GAD65) encephalitis is rare and few pediatric cases have been reported, with variable clinical presentations. A 14-year-old female adolescent was managed in our department. She had been treated for several months for drug-resistant temporal lobe epilepsy and gradually presented major anterograde amnesia with confusion. Upon her arrival at the University Hospital Centre, she showed a classical form of stiff person syndrome. The brain magnetic resonance imaging showed bitemporal hyperintensities and hypertrophy of the amygdala. The blood and cerebrospinal fluid were positive for GAD65 antibodies. At 2 years of immunosuppressive treatment and rehabilitation, the course showed partial improvement of the memory and neuropsychiatric impairment, and epilepsy that continued to be active. GAD65 antibodies are associated with various neurological syndromes, and this presentation combining limbic encephalitis and stiff person syndrome is the first pediatric form published to date; there are also few cases described in adults.

Case Report: Autoimmune Encephalitis Associated With Anti-glutamic Acid Decarboxylase Antibodies: A Pediatric Case Series

Background: Antibodies against glutamic acid decarboxylase (GAD) are associated with various neurologic conditions described in patients, including stiff person syndrome, cerebellar ataxia, refractory epilepsy, and limbic and extralimbic encephalitis. There have been some case reports and investigations regarding anti-GAD65 antibody-associated encephalitis in adult populations, but pediatric cases are rare. We retrospectively analyzed the clinical data of three anti-GAD65 antibody-positive patients to explore the diversity and clinical features of anti-GAD65 antibody-associated pediatric autoimmune encephalitis.

Methods: The clinical data of a series of three patients positive for anti-GAD65 antibody were retrospectively analyzed. GAD65 antibodies were determined in serum and CSF using a cell-based assay.

Results: All three patients were female, and the onset ages were 4 years and 9 months, 6 years, and 16 years old. Their clinical phenotypes included autoimmune limbic encephalitis, extralimbic encephalitis, and encephalitis combining limbic and extralimbic encephalitis. The clinical symptoms included seizures, memory deficits, drowsiness, dysautonomia, and headache. All patients had abnormal carinal MRI and EEG. All patients received immunotherapy and had transiently good responsiveness, but one patient then experienced relapse. In follow-up, one patient with extralimbic encephalitis recovered completely, while two patients with limbic involvement had poor outcomes with refractory focal epilepsy.

Conclusion: In addition to limbic encephalitis, extralimbic encephalitis is also an important phenotype in patients who are positive for anti-GAD65 antibodies. Early diagnosis and immunotherapy can improve the symptoms. However, patients with limbic encephalitis often have refractory epilepsy in the chronic phase and have a poor long-term outcome.

Rare presentation of anti-GAD-65 antibody-positive autoimmune encephalitis and simultaneous onset of type 1 diabetes mellitus in a paediatric patient

A 16-year-old female patient presented with subacute onset of headaches, changes in acute mental status, expressive aphasia and auditory hallucinations. New oedema and enhancement of the temporal lobe were seen on brain MRI, with correlating subclinical seizures seen on electroencephalogram. Simultaneously, our patient was diagnosed with new-onset type 1 diabetes mellitus, with positive anti-glutamic acid decarboxylase (anti-GAD-65) antibodies in the serum. Cerebrospinal fluid studies remained negative, including anti-GAD-65 antibodies. Clinical remission was achieved with corticosteroids and intravenous immunoglobulins.

Continuous Visual Focal Status Epilepticus as the Primary Presentation of NMDA-R and GAD65-R Autoimmune Epilepsy

Epilepsia partialis continua (EPC) has changed in its clinical and pathophysiological definition throughout time. Several etiologies have been described in addition to classic causes of EPC. The following case depicts a young woman who had a peculiar onset of epilepsy with a continuous visual aura becoming a form of chronic recurrent and non-progressive EPC. The patient was initially misdiagnosed as a non-neurological entity (assumed psychiatric in origin), but finally, an immune-mediated epilepsy was diagnosed, and EEG showed focal status epilepticus during evolution. Once the diagnosis was achieved and immune treatment was established, the patient is seizure free. Early identification of an immune basis in patients with epilepsy is important because immunotherapy can reverse the epileptogenic process and reduce the risk of chronic epilepsy. To date, this is the only case reported with EPC manifesting as a continuous visual aura associated with antiglutamic acid decarboxylase 65 (anti-GAD65) and anti-N-methyl-d-aspartate (anti-NMDA) antibodies.

Intravenous methylprednisolone or immunoglobulin for anti-glutamic acid decarboxylase 65 antibody autoimmune encephalitis: which is better?

BACKGROUND

Patients positive for anti-glutamic acid decarboxylase 65 (GAD65) antibodies have attracted increasing attention. Their clinical manifestations are highly heterogeneous and can be comorbid with tumors. Currently, there is no consensus on the therapeutic regimen for anti-GAD65-associated neurological diseases due to the clinical complexity, rarity and sporadic distribution. We reported six anti-GAD65 autoimmune encephalitis (AE) patients who received intravenous methylprednisolone (IVMP) or immunoglobulin (IVIG) or both. Then, we evaluated the therapeutic effect of both by summarizing results in previous anti-GAD65 AE patients from 70 published references.

RESULTS

Our six patients all achieved clinical improvements in the short term. Unfortunately, there was no significant difference between IVMP and IVIG in terms of therapeutic response according to the previous references, and the effectiveness of IVMP and IVIG was 45.56% and 36.71%, respectively. We further divided the patients into different subgroups according to their prominent clinical manifestations. The response rates of IVMP and IVIG were 42.65% and 32.69%, respectively, in epilepsy patients; 60.00% and 77.78%, respectively, in patients with stiff-person syndrome; and 28.57% and 55.56%, respectively, in cerebellar ataxia patients. Among 29 anti-GAD65 AE patients with tumors, the response rates of IVMP and IVIG were 29.41% and 42.11%, respectively. There was no significant difference in effectiveness between the two regimens among the different subgroups.

CONCLUSION

Except for stiff-person syndrome, we found that this kind of AE generally has a poor response to IVMP or IVIG. Larger prospective studies enrolling large numbers of patients are required to identify the optimal therapeutic strategy in the future.

Epilepsy in children with type 1 diabetes mellitus: Pathophysiological basis and clinical hallmarks

We provide an overview on the current knowledge about the association between epilepsy and type 1 diabetes mellitus (T1DM). People with T1DM have a 2-6-fold higher risk of epilepsy than the general population. The onset of T1DM anticipates the onset of epilepsy by a mean period between 1,5 and 2,8 years. These two disorders share four potential distinct pathogenic factors: a) genetic predisposition; b) factors involved in autoimmune responses (i.e. anti-glutamic acid decarboxylase antibodies-GADAbs); c) effects of hypo/hyperglycaemia; d) cerebrovascular damages resulting in ischaemic processes. Seizures semiology prominently includes focal (up to patterns of epilepsia partialis continua) or secondarily generalized seizures but also reflex seizures and various forms of generalized seizures. EEG abnormalities are more common in people with an inappropriate metabolic control with a prominent involvement of fronto-temporal regions. Epilepsy management does not differ between patients with and without diabetes and insulin, nutritional recommendations and physical activity may also produce significant benefits on seizures control. Possible therapeutic alternatives in selected cases include immunosuppressive drugs (in patients with GADAbs) and ketogenic diet.

Intravenous immunoglobulin for the treatment of autoimmune encephalopathy in children with autism

The identification of brain-targeted autoantibodies in children with autism spectrum disorder (ASD) raises the possibility of autoimmune encephalopathy (AIE). Intravenous immunoglobulin (IVIG) is effective for AIE and for some children with ASD. Here, we present the largest case series of children with ASD treated with IVIG. Through an ASD clinic, we screened 82 children for AIE, 80 of them with ASD. IVIG was recommended for 49 (60%) with 31 (38%) receiving the treatment under our care team. The majority of parents (90%) reported some improvement with 71% reporting improvements in two or more symptoms. In a subset of patients, Aberrant Behavior Checklist (ABC) and/or Social Responsiveness Scale (SRS) were completed before and during IVIG treatment. Statistically significant improvement occurred in the SRS and ABC. The antidopamine D2L receptor antibody, the anti-tubulin antibody and the ratio of the antidopamine D2L to D1 receptor antibodies were related to changes in the ABC. The Cunningham Panel predicted SRS, ABC, parent-based treatment responses with good accuracy. Adverse effects were common (62%) but mostly limited to the infusion period. Only two (6%) patients discontinued IVIG because of adverse effects. Overall, our open-label case series provides support for the possibility that some children with ASD may benefit from IVIG. Given that adverse effects are not uncommon, IVIG treatment needs to be considered cautiously. We identified immune biomarkers in select IVIG responders but larger cohorts are needed to study immune biomarkers in more detail. Our small open-label exploratory trial provides evidence supporting a neuroimmune subgroup in patients with ASD.

Severe dysautonomia as a main feature of anti-GAD encephalitis: Report of a paediatric case and literature review

INTRODUCTION

Anti-glutamic acid decarboxylase (anti-GAD65) antibodies are a rare cause of autoimmune encephalitis. This entity is mainly recognized in adults and very few cases were reported in children. We report on a paediatric case of anti-GAD encephalitis with severe presentation and uncontrollable dysautonomia.

CASE STUDY

A 9-year-old girl was referred to our department for refractory seizures and behavioral disturbances. Brain magnetic resonance imaging (MRI) was normal. Repeat screening for antineuronal antibodies showed negative results for anti-NMDA receptor antibodies but positive results for anti-GAD65 with a low positivity of anti-Ma2 antibodies. Although a transient improvement was noticed after immunomodulatory treatment, the patient developed severe intractable autonomic imbalance including dysrythmia, alternating bradycardia/tachycardia, hypotension/hypertension, hypothermia/hyperthermia and hyperhidrosis. She deceased six months after onset.

CONCLUSION

Our report intends to raise awareness of autoimmune encephalitis with anti-GAD65 antibodies which may involve extralimbic brain regions and manifest with fatal dysautonomia. We highlight the need for prompt diagnosis and aggressive management for this underdiagnosed entity in children.

GAD65 autoantibody characteristics in patients with co-occurring type 1 diabetes and epilepsy may help identify underlying epilepsy etiologies

BACKGROUND

Autoantibodies against the smaller isoform of glutamate decarboxylase (GAD65Ab) reflect autoimmune etiologies in Type 1 diabetes (T1D) and several neurological disorders, including Stiff Person Syndrome (SPS). GAD65Ab are also reported in cases of epilepsy, indicating an autoimmune component. GAD65Ab in patients with co-occurring T1D, epilepsy or SPS may be part of either autoimmune pathogenesis. To dissect the etiologies associated with GAD65Ab, we analyzed GAD65Ab titer, epitope specificity and enzyme inhibition in GAD65Ab-positive patients diagnosed with epilepsy (n = 28), patients with epilepsy and T1D (n = 10), patients with SPS (n = 20), and patients with T1D (n = 42).

RESULTS

GAD65Ab epitope pattern in epilepsy differed from T1D and SPS patients. Four of 10 patients with co-occurring T1D and epilepsy showed GAD65Ab profiles similar to T1D patients, while lacking GAD65Ab characteristics found in GAD65Ab-positive epilepsy patients. One of these patients responded well to anti-epileptic drugs (AEDs), while another patient did not require medication for seizure control. The third patient was refractory due to a diagnosis of meningioma. The response of the remaining patient to AEDs was unknown. GAD65Ab in the remaining six patients with T1D and epilepsy showed profiles similar to those in epilepsy patients.

CONCLUSIONS

Different autoimmune responses associated with T1D, epilepsy and SPS are reflected by disease-specific GAD65Ab patterns. Moreover, the epileptic etiology in patients diagnosed with both T1D and epilepsy may present two different etiologies regarding their epileptic condition. In one group T1D co-occurs with non-autoimmune epilepsy. In the other group GAD65Ab are part of an autoimmune epileptic condition.

Epilepsy and behavioral changes, type 1 diabetes mellitus and a high titer of glutamic acid decarboxylase antibodies

Autoantibodies to the 65 kDa isoform of glutamate acid decarboxylase (GAD65Ab) are associated with a range of clinical disorders, including type 1 diabetes (T1D) and stiff-person syndrome (SPS). In this article we describe a young girl who was diagnosed with T1D at the end of her first year of life and developed drug-resistant epilepsy 18 months later, followed by behavioral disturbances. She was admitted to our center at the age of 5 yr, at which time high GAD65Ab titers were detected in the patient's serum and cerebrospinal fluid (CSF). The titer remained elevated during 19 months of follow-up. Furthermore, GAD65Ab in both serum and CSF showed epitope binding characteristics similar to those observed for GAD65Ab in SPS patients, and GAD65Ab in the serum reduced GAD65 enzyme activity. Our results suggest an association between high GAD65Ab titers and epilepsy in children with T1D. Careful titration and characterization of GAD65Ab regarding inhibition of enzyme activity and epitope specificity may be helpful in identifying T1D patients at risk for neurological complications.

Type 1 diabetes and GAD65 limbic encephalitis: a case report of a 10-year-old girl

Limbic encephalitis is a rare neurological disorder that may be difficult to recognize. Clinical features include memory impairment, temporal lobe seizures and affective disturbance. We report the case of a 10-year-old girl with type 1 diabetes mellitus that presented with seizures, depressed mood and memory changes. The diagnosis of glutamic acid decarboxylase 65 (GAD65) mediated limbic encephalitis relied on cerebral magnetic resonance imaging lesions and high serological and cerebrospinal fluid GAD65-antibodies titers. High-dose steroidal therapy was started with clinical improvement. Relapse led to a second high-dose steroid treatment followed by rituximab with remission. A correlation between serum GAD65-antibodies levels and symptoms was found, demonstrating GAD65-antibodies titers may be useful for clinical follow-up and immunotherapy guidance. This report raises awareness of this serious neurological condition that may be associated with type 1 diabetes, underlining the importance of an early diagnosis and prompt treatment for a better prognosis.

Antibody-Mediated Autoimmune Encephalitis in Childhood

BACKGROUND

The differential diagnosis of encephalitis in childhood is vast, and evaluation for an etiology is often unrevealing. Encephalitis by way of autoimmunity has long been suspected, as in cases of acute disseminated encephalomyelitis; however, researchers have only recently reported evidence of antibody-mediated immune dysregulation resulting in clinical encephalitis.

MAIN FINDINGS

These pathologic autoantibodies, aimed at specific neuronal targets, can result in a broad spectrum of symptoms including psychosis, catatonia, behavioral changes, memory loss, autonomic dysregulation, seizures, and abnormal movements. Autoimmune encephalitis in childhood is often quite different from adult-onset autoimmune encephalitis in clinical presentation, frequency of tumor association, and ultimate prognosis. As many of the autoimmune encephalitides are sensitive to immunotherapy, prompt diagnosis and initiation of appropriate treatment are paramount.

CONCLUSIONS

Here we review the currently recognized antibody-mediated encephalitides of childhood and will provide a framework for diagnosis and treatment considerations.

Risk of epilepsy in type 1 diabetes mellitus: a population-based cohort study

AIMS/HYPOTHESIS

Type 1 diabetes mellitus is a major public health problem of increasing global concern, with potential neurological complications. A possible association exists between type 1 diabetes and subsequent epilepsy. This study evaluated the relationship between type 1 diabetes and epilepsy in Taiwan.

METHODS

Claims data from the Taiwan National Health Insurance Research Database were used to conduct retrospective cohort analyses. The study cohort contained 2568 patients with type 1 diabetes, each of whom was frequency-matched by sex, urbanisation of residence area and index year with ten patients without type 1 diabetes. Cox proportional hazard regression analysis was conducted to estimate the effects of type 1 diabetes on epilepsy risk.

RESULTS

In patients with type 1 diabetes, the risk of developing epilepsy was significantly higher than that in patients without type 1 diabetes (p < 0.0001 for logrank test). After adjustment for potential confounders, the type 1 diabetes cohort was 2.84 times as likely to develop epilepsy than the control cohort was (HR 2.84 [95% CI 2.11, 3.83]).

CONCLUSIONS/INTERPRETATION

Patients with type 1 diabetes are at an increased risk of developing epilepsy. Metabolic abnormalities of type 1 diabetes, such as hyperglycaemia and hypoglycaemia, may have a damaging effect on the central nervous system and be associated with significant long-term neurological sequelae. The causative factors between type 1 diabetes and the increased risk of epilepsy require further investigation.

Limbic Encephalitis Associated With GAD65 Antibodies: Brief Review of the Relevant literature

Recently, many cases of autoimmune limbic encephalitis with positive GAD65 (glutamic acid decarboxylase) antibodies have been described in the scientific literature. However, it remains an understudied topic of great relevance to practicing neurologists. Thus, we report here a review of published cases, in English, of autoimmune limbic encephalitis with this type of antibodies, focusing on presenting symptoms and signs, associated conditions, and findings upon investigation. We also report treatment responses. We aim to offer a better description of the clinical spectrum of autoimmune limbic encephalitis associated with GAD65 antibodies as well as to expose its paraclinical features and outcome.

Diabetes and epilepsy in children and adolescents

Over the last years, there has been an increasing interest in the potential association between type 1 diabetes (T1D) and epilepsy. Both T1D and epilepsy are common conditions in children and adolescents, and therefore, their association might represent simply a coincidence or be related to common underlying mechanisms with a potential causal relationship. Few epidemiological studies have been performed in the pediatric population, and they have reached discordant conclusions, with some studies reporting an increased prevalence of epilepsy in children and adolescents with T1D, whereas others have not confirmed this finding. Several mechanisms could explain the occurrence of epilepsy in young people with T1D, such as metabolic abnormalities (hypo/hyperglycemia) and autoantibodies, along with a genetic predisposition and the presence of brain lesions/damage. Further studies are required to better define whether there is a causal relationship between the two conditions and to understand the underlying mechanisms.

Removal kinetics of antibodies against glutamic acid decarboxylase by various plasmapheresis modalities in the treatment of neurological disorders

Plasmapheresis is one of the acute treatment modalities for neurological disorders associated with antibodies against glutamic acid decarboxylase (anti-GAD). However, there is little information about the removal kinetics of anti-GAD by various plasmapheresis modalities. Here, we investigated the removal rate of anti-GAD and fibrinogen (Fib) by immunoadsorption (IA), plasma exchange using a conventional plasma separator (OP-PE), and plasma exchange using a high cut-off selective membrane plasma separator (EC-PE) in two cases of anti-GAD-associated neurological diseases. In case 1, IA and OP-PE were used, and the percent reductions were as follows: anti-GAD: 38.2% and 69.1% and Fib: 67.7% and 68.2%, respectively. In case 2, OP-PE and EC-PE were used, and the percent reductions were as follows: anti-GAD: 65.8% and 48.5% and Fib: 68.5% and 19.8%, respectively. OP-PE could remove anti-GAD more efficiently than IA. Further, EC-PE could maintain coagulation factors such as Fib better than IA and OP-PE. It is important to select the appropriate plasmapheresis modality on the basis of the removal kinetics.

Autoimmunity and inflammation in status epilepticus: from concepts to therapies

The understanding of immunological mechanisms underlying some forms of epilepsy and encephalitis has rapidly increased for the last 10 years leading to the concept of status epilepticus of autoimmune origin. Actual treatment recommendations regarding autoimmune status epilepticus are based on retrospective case studies, pathophysiological considerations and experts' opinion. In addition, there are no clear indicators to predict outcome. In situations where autoimmune mechanisms are suspected in patients with status epilepticus, there is evidence that earlier treatment is related to better outcome. Increased awareness is mandatory to decrease the number of patients with major neurological problems or fatal outcome, which is overall about 50%. We here summarize findings of all pediatric and adult patients reported to date, and review the current state of knowledge in the field of immune therapeutic approaches of status epilepticus.

Anti-glutamic Acid decarboxylase antibody associated limbic encephalitis in a child: expanding the spectrum of pediatric inflammatory brain diseases

Anti-glutamic acid decarboxylase directed antibodies are a rare cause of autoimmune limbic encephalitis that is relatively resistant to immunotherapy. Here we report a 15-year-old boy with nonparaneoplastic, anti-glutamic acid decarboxylase limbic encephalitis presenting with subacute headache, memory disturbance, psychiatric symptoms, and seizures. At onset, his memory disturbance manifested as transient global amnesia-like episodes. Clinical remission was achieved with rituximab, intravenous immunoglobulin, and corticosteroids.

Non-convulsive status epilepticus associated with glutamic acid decarboxylase antibody

Autoimmune encephalitis associated with glutamic acid decarboxylase antibodies (GAD-Ab) often presents with treatment-resistant partial seizures, as well as other central nervous system symptoms. In contrast to several other well-characterized autoantibodies, GAD-Ab has very rarely been associated with status epilepticus. We report a 63-year-old woman initially admitted with somnolence and psychiatric findings. The EEG findings, of generalized and rhythmical slow spike-wave activity over the posterior regions of both hemispheres, together with the clinical deterioration in responsiveness, led to the diagnosis of non-convulsive status epilepticus. Investigation of a broad panel of autoantibodies, revealed only increased serum GAD-Ab levels. Following methylprednisolone and intravenous immunoglobulin treatments, the patient's neurological symptoms improved, EEG findings disappeared and GAD-Ab levels significantly decreased. GAD-Ab should be added to the list of anti-neuronal antibodies associated with non-convulsive status epilepticus. Disappearance of clinical findings and seroreversion after immunotherapy suggest that GAD-Ab might be involved in seizure pathogenesis. 

Seizures and type 1 diabetes mellitus: current state of knowledge

In this review, we will try to analyze the possible coexistence between epilepsy or seizures and type 1 diabetes mellitus (T1DM), in order to establish if there is more than a casual association, and to investigate possible mechanisms underlying this link. Anti-glutamic acid decarboxylase antibodies (GAD-Abs) have been associated with T1DM and a great number of neurological diseases such as epilepsy. Epilepsy can be a feature of a large variety of autoimmune or inflammatory disorders. GAD-Abs can have a role at the basis of the possible link between epilepsy and T1DM, although their real pathogenetic mechanism in neurological diseases is still unknown. Metabolic conditions such as hypoglycemia and hyperglycemia, common problems in diabetic patients, may be also implicated, even if their underlying mechanism is minimally understood.

The association of anti-glutamic acid decarboxylase antibodies with different neurological findings in childhood

Glutamic acid decarboxylase antibodies can rarely be associated with various neurological syndromes, which are usually present in adults. Here, we present 2 affected children. Our first patient had a diagnosis of epilepsy and presented with continuous involuntary movements and multifocal myoclonic seizures following an infection at the age of 9 months. Anti-glutamic acid decarboxylase antibodies were found in the serum and cerebrospinal fluid. A partial response was obtained from intravenous immunoglobulin, steroid, and plasmapheresis treatment. The other patient presented with a clinical picture of acute cerebellar ataxia and mutism at the age of 6 years and recovered fully following intravenous immunoglobulin treatment. Neurological findings due to anti-glutamic acid decarboxylase antibodies may be more common in children than previously thought, and achieving an early diagnosis can be important for prompt treatment.

Association of epilepsy and type 1 diabetes mellitus in children and adolescents: is there an increased risk for diabetic ketoacidosis?

OBJECTIVE

To estimate the prevalence of epilepsy and possible risk factors in children and adolescents with diabetes mellitus.

STUDY DESIGN

We conducted an observational cohort study based on the Diabetes Patienten Verlaufsdokumentation database including data from 45 851 patients (52% male) with type 1 diabetes mellitus, age 13.9 ± 4.3 years (mean ± SD) and duration of diabetes mellitus 5.4 ± 4.2 years. The database was searched for the concomitant diagnosis of epilepsy or epileptic convulsions and for antiepileptic medication.

RESULTS

A total of 705 patients with epilepsy were identified, giving a prevalence of 15.5 of 1000. A total of 375 patients were treated with antiepileptic medication, and 330 patients were without anticonvulsive therapy. Patients with epilepsy were younger at onset of diabetes mellitus and shorter than patients without epilepsy, and their weight and body mass index were comparable. No difference could be demonstrated for metabolic control, type of insulin treatment, insulin dose, and prevalence of B-cell specific autoantibodies. The frequency of severe hypoglycemia was lower in patients treated with antiepileptic medication. The risk for diabetic ketoacidosis was almost double in patients with epilepsy compared with patients with type 1 diabetes mellitus alone (P < .01).

CONCLUSION

Children and adolescents with diabetes mellitus show an increased prevalence of epileptic seizures. For unknown reasons, there is an association between epilepsy and diabetic ketoacidosis in children with type 1 diabetes mellitus.

Long-lasting remission of type 1 diabetes following treatment with topiramate for generalized seizures

We report a case of unusually long-lasting remission of type 1 diabetes (T1D). The patient, a Caucasian man, at the age of 43 years developed a ketotic diabetes, classified as type 1 based on clinical presentation and positivity for islet autoantibodies. Shortly after diabetes onset, oral topiramate was added to preexisting valproic acid for generalized seizures and maintained thereafter. Initial intensive insulin treatment was rapidly reduced to low doses (3 Units/day) maintained for a long time and then discontinued at month 55; fasting glucose and glycosylated hemoglobin were basically normalized at 58 months. An oral glucose tolerance test performed at month 53 showed an impaired fasting glucose (6.0 mmol/l) and a value slightly above the threshold for the diagnosis of diabetes at 2 h (11.2 mmol/l). We hypothesize that this unusually prolonged preservation of β-cell function might be ascribed to the concomitant therapy with topiramate, an antiepileptic agent with demonstrated efficacy as antidiabetic in type 2 diabetes (T2D). Topiramate should be further investigated as candidate agent for the preservation of β-cell function also in T1D.

[Association of type 1 diabetes mellitus and epilepsy in children. A cohort of 10 cases]

The association of type 1 diabetes mellitus (DM) and epilepsy has been previously reported. However, the physiopathology of this association remains misunderstood.

OBJECTIVE

To describe epilepsy combined with type 1 DM in children.

METHODS

Retrospective monocentric study of all the epileptic and type 1 diabetic children consulting at the Timone University Hospital, Marseille, France. For each patient, the type of epilepsy and its electroclinical and radiographic characteristics were studied as well as the type of diabetes (biological characteristics, glycemic control), and the onset of these 2 diseases.

RESULTS

Ten patients are reported. Five suffered from generalized epilepsy (4 idiopathic, 1 nonidiopathic) and 5 from focal epilepsy (4 non-idiopathic, 1 idiopathic). For most of these cases, presence of GAD (glutamic acid decarboxylase) autoantibodies were confirmed and epilepsy followed diabetes.

CONCLUSIONS

The 2 most common types of epilepsy in this association are idiopathic generalized epilepsy and non-idiopathic temporal epilepsy. Several mechanisms could be involved (immune, glycemia, and genetic disorders).

Clinical significance of glutamic acid decarboxylase antibodies in patients with epilepsy

PURPOSE

Glutamic acid decarboxylase antibodies (GADAs) have been detected in patients with epilepsy, but the clinical determinants of epilepsy associated with GADA have not been defined.

METHODS

We analyzed GADA with a radioimmunoassay in sera of 253 well-characterized patients with epilepsy and 200 control subjects. The positive samples were confirmed by immunohistochemistry and western blotting (WB). Sera were screened for other autoantibodies.

RESULTS

GADA were detected in 15 patients (5.9%) and in three control subjects (1.5%) (p = 0.026). Seven patients (2.8%) had high GADA titers [>or=1,000 relative units (RUs)/ml], six of whom had temporal lobe epilepsy (TLE). All three GADA-positive control subjects had low titers. Two of the five patients with high GADA titers and available cerebrospinal fluid (CSF) samples had intrathecal synthesis (IS) of GADA; one patient had CSF oligoclonal bands. The prevalence of increased levels of GADA tended to be higher in patients with TLE than in patients with extra-TLE [odds ratio (OR) 1.32, 95% confidence interval (CI) 0.39-4.42; p = 0.657]. The patients with high GADA titers had significantly higher number of other autoantibodies compared to the patients with low GADA titers (p = 0.001) and the patients with normal GADA (p < 0.001).

DISCUSSION

High GADA titers were present in a subgroup of patients; close to 90% had TLE. The immunologic profile of these patients suggests that the most probable origin of their epilepsy is autoimmune. A positive IS of GADA may be a marker of an ongoing immune response that could identify those patients in whom a trial with immunosuppressive therapy might be warranted.

Does epilepsy occur more frequently in children with Type 1 diabetes?

AIM

Hypoglycaemic seizures are common in children with diabetes and electroencephalogram abnormalities are well recognised in this patient group. Elevated antibodies to glutamic acid decarboxylase, a major auto-antigen in Type 1 diabetes, are also implicated in a number of neurological disorders. Despite these associations, the question of whether children with diabetes are more prone to epilepsy, possibly as a result of lowered seizure threshold, has not been previously studied. We aimed to determine the prevalence and type of epilepsy in a large paediatric diabetes clinic.

METHODS

An audit by chart review was carried out at the Diabetes Clinic at the Royal Children's Hospital, Melbourne, Australia. Clinical, demographical, biochemical, EEG and neuro-imaging data were recorded.

RESULTS

Of 1384 children and adolescents aged 0-19 years with Type 1 diabetes, we identified 12 with active epilepsy (prevalence of 8.7/1000), the majority of whom had idiopathic generalised epilepsy and benign focal epilepsy of childhood. These findings are similar to those in the general population.

CONCLUSION

Childhood epilepsy is no more frequently encountered in children and adolescents with Type 1 diabetes than in the general paediatric population.

[Rasmussen's syndrome, an autoimmune disease]

Rasmussen's disease is an inflammatory, chronic and progressive brain disorder that usually presents with neocortical focal seizures resistant to conventional treatment and culminates in severe deterioration with hemiparesis, cognitive decline and aphasia. Viral infections and antibodies to the GluR3 receptor have been implicated in the physiopathology of this illness and T-cell mediation may play a role in the cerebral inflammatory process. Classical treatment consists of hemispherectomy of various magnitudes depending on cerebral involvement. The association between therapy-resistant epilepsy and autoimmune phenomena due to antibodies against glutamic acid decarboxylase (anti-GAD) have very recently begun to be studied. The discovery of this association led to a new focus and alternative therapies with immunosuppressors, immunoglobulins, steroids and plasmapheresis, alone or in combination, have begun to be tested with variable success. We describe a boy who was diagnosed in the early stages of Rasmussen's syndrome. He tested positive for anti-GAD antibodies and received treatment with immunoglobulins and steroids. After treatment the boy tested negative for anti-GAD antibodies and he remains asymptomatic after ten months.