Recurrent absence status epilepticus (spike-and-wave stupor) associated with lamotrigine therapy

Clinical features of catatonic non-convulsive status epilepticus: A systematic review of cases

OBJECTIVE

Non-convulsive status epilepticus (NCSE) can manifest as catatonia, although it is unclear how frequently such cases have been reported. The common clinical features of these two conditions are also unclear.

METHODS

Using the MEDLINE and Embase databases, we performed a systematic literature search to identify cases diagnosed with both catatonia, according to the Bush-Francis Catatonia Rating Scale, and NCSE, according to the Salzburg Consensus Criteria (last search: March 29, 2021). We extracted data on demographics, clinical features of catatonia, EEG findings, and treatments.

RESULTS

A total of 66 patients with catatonic NSCE (men, 49%; mean age, 42.0 years) were identified from our search. Of the 66 cases described: 30 (46%) showed motor symptoms; 35 (38%) occurred in patients with preceding episodes of epileptic seizures; 19 (29%) showed subtle ictal clinical phenomena, such as minor twitching of the mouth, periorbital region, and extremities; 22 (33%) presented with psychiatric symptoms prior to the onset of catatonia; 17 (26%) had a history of psychiatric diseases; and in 10 cases (15%), NSCE was confirmed by intentional or non-intentional long-term EEG monitoring. Benzodiazepines were used as the initial treatment for NCSE in 30 cases (49%), of which 20 cases (73%) improved with monotherapy.

DISCUSSION

A substantial number of cases included in the present review involved catatonia without any symptoms indicative of epilepsy, suggesting that NCSE may be misdiagnosed as a psychiatric disease, and highlighting the importance of the accurate diagnosis and treatment of NCSE in patients presenting with catatonia.

Pediatric Absence Status Epilepticus: Prolonged Altered Mental Status in an 8-Year-Old Boy

Absence status epilepticus is characterized by a prolonged state of impaired consciousness or altered sensorium with generalized electroencephalographic abnormalities. It is most commonly diagnosed in patients with known idiopathic generalized epilepsy; however, it may also be the first presentation of epilepsy. Due to the subtle and variable manifestations of the condition, absence status epilepticus may be underrecognized, particularly in children. We present the case of an 8-year-old boy who experienced two episodes of prolonged altered mental status, subsequently determined to be absence status epilepticus with idiopathic generalized epilepsy with phantom absences. We discuss the classification, pathophysiology, clinical presentation, and electroencephalographic findings of pediatric absence status epilepticus and provide a practical overview for management.

Drug-induced status epilepticus

Drug-induced status epilepticus (SE) is a relatively uncommon phenomenon, probably accounting for less than 5% of all SE cases, although limitations in case ascertainment and establishing causation substantially weaken epidemiological estimates. Some antiepileptic drugs, particularly those with sodium channel or GABA(γ-aminobutyric acid)-ergic properties, frequently exacerbate seizures and may lead to SE if used inadvertently in generalized epilepsies or less frequently in other epilepsies. Tiagabine seems to have a particular propensity for triggering nonconvulsive SE sometimes in patients with no prior history of seizures. In therapeutic practice, SE is most commonly seen in association with antibiotics (cephalosporins, quinolones, and some others) and immunotherapies/chemotherapies, the latter often in the context of a reversible encephalopathy syndrome. Status epilepticus following accidental or intentional overdoses, particularly of antidepressants or other psychotropic medications, has also featured prominently in the literature: whilst there are sometimes fatal consequences, this is more commonly because of cardiorespiratory or metabolic complications than as a result of seizure activity. A high index of suspicion is required in identifying those at risk and in recognizing potential clues from the presentation, but even with a careful analysis of patient and drug factors, establishing causation can be difficult. In addition to eliminating the potential trigger, management should be as for SE in any other circumstances, with the exception that phenobarbitone is recommended as a second-line treatment for suspected toxicity-related SE where the risk of cardiovascular complications is higher anyways and may be exacerbated by phenytoin. There are also specific recommendations/antidotes in some situations. The outcome of drug-induced status epilepticus is mostly good when promptly identified and treated, though less so in the context of overdoses. This article is part of a Special Issue entitled "Status Epilepticus".

Neurotoxic emergencies

This article is intended for clinicians treating neurotoxic emergencies. Presented are causative agents of neurotoxic emergencies, many of which are easily mistaken for acute psychiatric disorders. Understanding the wide variety of agents responsible for neurotoxic emergencies and the neurotransmitter interactions involved will help the psychiatrist identify and treat this challenging population.

The safety and tolerability of newer antiepileptic drugs in children and adolescents

The newer antiepileptic drugs (AEDs) provide more therapeutic options and overall improved safety and tolerability for patients. To provide the best care, physicians must be familiar with the latest tolerability and safety data. This is particularly true in children, given there are relatively fewer studies examining the effects of AEDs in children compared with adults. Since we now have significant paediatric literature on each of these agents, we provide a comprehensive and current literature review of the newer AEDs, focusing on safety and tolerability data in children and adolescents. Because the safety profiles in children differ from those in adults, familiarity with this literature is important for child neurologists and other paediatric caregivers. We have organized the data by organ system for each AED for easier reference.

Absence seizures: a review of recent reports with new concepts

Absence seizures with bilateral spike-wave (SW) complexes at 3Hz are divided into the childhood form, with onset at around 6 years of age, and the juvenile form, with onset usually at 12 years of age. These seizures typically last 9-12s and, at times, are activated by hyperventilation and occasionally by photic stimulation. Generalized tonic-clonic (GTC) seizures may also occur, especially in the juvenile form. There may be cognitive changes, in addition to linguistic and behavioral problems. Possible mechanisms for epileptogenesis may involve GABAergic systems, but especially T-calcium channels. The thalamus, especially the reticular nucleus, plays a major role, as does the frontal cortex, mainly the dorsolateral and orbital frontal areas, to the extent that some investigators have concluded that absence seizures are not truly generalized, but rather have selective cortical networks, mainly ventromesial frontal areas and the somatosensory cortex. The latter network is a departure from the more popular concept of a generalized epilepsy. Between the "centrencephalic" and "corticoreticular" theories, a "unified" theory is presented. Proposed genes include T-calcium channel gene CACNA1H, likely a susceptible gene in the Chinese Han population and a contributory gene in Caucasians. Electroencephalography has revealed an interictal increase in prefrontal activity, essential for the buildup of the ictal SW complexes maximal in that region. Infraslow activity can also be seen during ictal SW complexes. For treatment, counter to common belief, ethosuximide may not increase GTC seizures, as it reduces low-threshold T-calcium currents in thalamic neurons. Valproic acid and lamotrigine are also first-line medications. In addition, zonisamide and levetiracetam can be very helpful in absence epilepsy.

Diagnosis and management of nonconvulsive status epilepticus in children

Nonconvulsive status epilepticus (NCSE) encompasses a wide range of diagnoses with variable outcomes and treatment recommendations. In children, NCSE can be observed in various conditions, including acute neurological injuries, specific childhood epilepsy syndromes and other neurological conditions, and can also be observed in individuals with learning difficulties. NCSE in children is thought to be under-recognized, and further studies examining the electrographic characteristics of very young children in NCSE would aid the prompt recognition of additional patients. Some subtypes of NCSE are probably more harmful than others, and long-term prospective studies are needed to evaluate the damaging potential of NCSE itself as opposed to that of the underlying circumstances in which it occurs. Specific data in childhood are clearly lacking, but extrapolation from adult studies indicates that aggressive treatment is most warranted in comatose patients. By contrast, a cautious approach seems to be indicated for absence status epilepticus, complex partial status epilepticus and electrical status epilepticus during sleep.

LAMOTRIGINE REDUCES INTESTINAL I/R INJURY IN THE RAT

I/R injury of the intestine is a life-threatening emergency with mortality rates still more than 60%. We have investigated the protective effect of lamotrigine (LTG), an antiepileptic drug, which has an established neuroprotective effect, on intestinal I/R injury in rats. Forty-eight Wistar albino rats were divided into three groups: a sham-operated group (no I/R injury; n = 16), an ischemic control group (I/R, n = 16), and an LTG-treated group (pretreatment 5 mg kg-1 LTG + IR; n = 16). A marker for lipid peroxidation, malondialdehyde, free radical scavengers, glutathione peroxidase, catalase, and superoxide dismutase levels, an index of polymorphonuclear neutrophils, myeloperoxidase activity, and mucosal damage were investigated. Malondialdehyde levels, myeloperoxidase activity, and the severity of mucosal damage were decreased in the LTG group. Moreover, in the LTG group, glutathione peroxidase and superoxide dismutase levels were higher compared with the I/R group. The pretreatment of rats with LTG before intestinal ischemia ameliorates the mucosal damage in intestinal I/R injury probably by altering lipid peroxidation, neutrophil accumulation, and antioxidant activity.