Focal epileptic episodes associated with hypoglycemia in children with diabetes

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.

The effect of age at onset of type 1 diabetes mellitus on epilepsy vulnerability

AIMS

To examine whether type 1 diabetes age onset correlates with epilepsy incidence.

METHODS

We used type 1 diabetes longitudinal data with onset age ≤ 40 years enrolled in Taiwan National Health Insurance program to examine type 1 diabetes onset age effect on epilepsy occurrence.

RESULTS

In 6,165 type 1 diabetes patients, onset age groups included 3,571 patients (58%) ≤ 18 years (childhood-onset) and 2,594 patients (42%) > 18 years (adulthood-onset). After 8.6 years median follow-up following type 1 diabetes onset, epilepsy incidence rate in adulthood-onset group was 2.26-fold higher than that in childhood-onset group. Epilepsy incidence rate ratio was lowest in those with onset age 6-12 years in comparison to that in patients with onset age ≤ 6 years, but was highest in onset age of 30-40 years. Longer follow-up duration correlates with higher epilepsy risk in adulthood-onset group. Multiple logistic regression analysis showed that onset age 30-40 years, male, more than one diabetic ketoacidosis episode, and unprovoked seizure events were independent risk factors for epilepsy following type 1 diabetes onset.

CONCLUSIONS

There is age-related vulnerability to epilepsy following type 1 diabetes onset. Adulthood-onset type 1 diabetes is an independent risk factor for epilepsy susceptibility after type 1 diabetes.

GAD-65 autoantibody associated epilepsy

Objectives The aim of this report is to describe a case of GAD-65 autoantibody associated epilepcy, diagnosed long before the onset of autoimmune diabetes. Case presentation This report presents a 36-year-old female with type 1 diabetes, diagnosed at the age of 26, and a cryptogenic focal epilepsy with complex partial seizures, with duration of 2-3 min and frequency of 5-6 per month, diagnosed at 16 years of age. Electroencephalography revealed epileptiform abnormalities temporally and centro-parietally on the left and temporally on the right with forward propagation on both sides. Due to the drug refractory seizures, titers of GAD-65 autoantibodies were examined (19 years after the diagnosis of epilepsy and 9 years after the diagnosis of diabetes) and were found to be elevated in serum and cerebrospinal fluid, strongly supporting its autoimmune genesis. Insulin pump therapy was used in this patient with a beneficial effect on glycemia. Conclusions Autoimmune epilepsy is a clinical entity and should be taken into consideration in patients with other autoimmune diseases, especially diabetes, and with drug refractory seizures, even preceding the onset of diabetes. Achieving stable glycemic control, including the usage of the new technologies in type 1 diabetes treatment, is vital in these cases.

Association between type 1 diabetes mellitus and risk of epilepsy: A meta-analysis of observational studies

A potential association between type 1 diabetes mellitus and subsequent epilepsy emerged in recent studies. This study aimed to evaluate the possible relationship between type 1 diabetes mellitus and epilepsy using meta-analysis. Pubmed, ISI Web of Knowledge, Embase and Cochrane Library were searched for potential studies of the association between type 1 diabetes mellitus and epilepsy from inception to February 1, 2017. Two investigators independently screened studies for inclusion and extracted related data; discrepancies were solved by consensus. Random effects model of Hazard Ratio (HR) was used to estimate the strength of association. We identified 13 papers from potentially relevant articles of which 3 cohort studies met the inclusion criteria. Random effects meta-analysis showed that type 1 diabetes mellitus was associated with an increased risk of epilepsy with HR = 3.29 (95% CI: 2.61-4.14; I² = 0, p = 0.689). Similar results were observed in type 1 diabetes mellitus patents younger than 18-years-old with HR = 2.96 (95% CI: 2.28-3.84; I² = 0, p = 0.571). Meta-analysis of 2 studies that adjusted for potential confounders yielded an increased risk of epilepsy with HR = 2.89 (95% CI: 2.26-3.70; I² = 0, p = 0.831). The meta-analysis indicates that type 1 diabetes mellitus is associated with a statistically significant increased risk for epilepsy compared to those without type 1 diabetes mellitus.

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.

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.

Severe hypoglycemia in a juvenile diabetic rat model: presence and severity of seizures are associated with mortality

It is well accepted that insulin-induced hypoglycemia can result in seizures. However, the effects of the seizures, as well as possible treatment strategies, have yet to be elucidated, particularly in juvenile or insulin-dependent diabetes mellitus (IDDM). Here we establish a model of diabetes in young rats, to examine the consequences of severe hypoglycemia in this age group; particularly seizures and mortality. Diabetes was induced in post-weaned 22-day-old Sprague-Dawley rats by streptozotocin (STZ) administered intraperitoneally (IP). Insulin IP (15 U/kg), in rats fasted (14-16 hours), induced hypoglycemia, defined as <3.5 mM blood glucose (BG), in 68% of diabetic (STZ) and 86% of control rats (CON). Seizures occurred in 86% of STZ and all CON rats that reached hypoglycemic levels with mortality only occurring post-seizure. The fasting BG levels were significantly higher in STZ (12.4 ± 1.3 mM) than in CON rodents (6.3 ± 0.3 mM), resulting in earlier onset of hypoglycemia and seizures in the CON group. However, the BG at seizure onset was statistically similar between STZ (1.8 ± 0.2 mM) and CON animals (1.6 ± 0.1 mM) as well as between those that survived (S+S) and those that died (S+M) post-seizure. Despite this, the S+M group underwent a significantly greater number of seizure events than the S+S group. 25% glucose administered at seizure onset and repeated with recurrent seizures was not sufficient to mitigate these continued convulsions. Combining glucose with diazepam and phenytoin significantly decreased post-treatment seizures, but not mortality. Intracranial electroencephalograms (EEGs) were recorded in 10 CON and 9 STZ animals. Predictive EEG changes were not observed in these animals that underwent seizures. Fluorojade staining revealed damaged cells in non-seizing STZ animals and in STZ and CON animals post-seizure. In summary, this model of hypoglycemia and seizures in juvenile diabetic rats provides a paradigm for further study of underlying mechanisms. Our data demonstrate that severe hypoglycemia (<2.0 mM) is a necessary precondition for seizures, and the increased frequency of these seizures is associated with mortality.

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.

Magnetic resonance imaging and positron emission tomography findings in status epilepticus following severe hypoglycemia

We recently experienced a case with asymmetrical cortical abnormality on MRI with focal status epilepticus following severe hypoglycemia. The cerebral blood flow and metabolisms for oxygen and glucose were determined using positron emission tomography (PET) during focal status epilepticus following severe hypoglycemia and at the follow-up period. Prolonged seizure activity produced profound glucose hypermetabolism and mild hyperemia in the region of the presumed cortical focus of epilepsy and in structures anatomically remote from the focus, corresponding to the areas of abnormal signal intensity on the MRI. The patient remained comatose and exhibited a diffuse hypoperfusion/hypometabolism and symmetrical brain atrophy on the follow-up PET and MRI, respectively. Cytotoxic brain edema due to profound glucose metabolism without compensatory increase of the blood flow during status epilepticus may account for the brain abnormality observed on the early MRI. Simultaneous examination of the cerebral blood flow and metabolism using PET can provide useful information about the pathology in patients with status epilepticus.

Seizures as the only clinical manifestation of reactive hypoglycemia: a case report

A 45-yr old diabetic patient, who had received a diagnosis of grand mal epilepsy, for two episodes of nocturnal tonic-clonic convulsions, underwent continuous glucose monitoring (CGM). During CGM, the patient had an episode of tonic-clonic convulsion, and at the same time a prolonged nocturnal hypoglycemia (<2.2 mmol/l) was observed. CGM revealed that tonic-clonic convulsions, which had been interpreted as a manifestation of epilepsy, were in fact a symptom of severe hypoglycemia. In order to assess the pathogenesis of hypoglycemia, the patient underwent a 75-g oral glucose tolerance test, that was interrupted shortly afterwards for hypoglycemic symptoms (i.e., reactive hypoglycemia). To our knowledge, this is the first case ever reported of reactive hypoglycemia associated with Type 2 diabetes.

The biochemical investigation of epilepsy in childhood

Metabolic disorders are a relatively uncommon, but important, cause of childhood seizures. Routinely searching for a metabolic disorder in epilepsy is usually unrewarding. Children and adolescents with epilepsy can be selected for appropriate biochemical investigation by considering the seizure type, age of onset, EEG appearance, family history, clinical findings and the results of brain imaging. A limited number of biochemical screening tests can be used to categorize the more common metabolic disorders associated with seizures.