Psychotropic effects of antiepileptic drugs

Beneficial and adverse psychotropic effects of antiepileptic drugs in patients with epilepsy: a summary of prevalence, underlying mechanisms and data limitations

Antiepileptic drugs (AEDs) can have both beneficial and adverse psychotropic effects. They act on neurotransmitter systems, neuronal ion permeability and other targets, although the exact mechanisms are not generally fully elucidated. A systematic review of the literature reveals evidence for both positive and negative effects on depression, anxiety, aggression, psychosis and sleep in patients with epilepsy. Topiramate, vigabatrin, levetiracetam, tiagabine and zonisamide have been associated primarily with adverse psychotropic effects, whilst gabapentin, pregabalin, lacosamide and lamotrigine, in particular, have demonstrated a more beneficial psychotropic profile, especially with regard to affective symptoms. This review, however, identifies specific methodological issues with studies that have reported on the psychotropic effects of AEDs, suggesting that some of the findings might be inconclusive or unreliable because of confounding factors, particularly the presence of psychiatric history. More rigorous double-blind, randomized, placebo-controlled trials on larger numbers of patients with epilepsy, with clear inclusion/exclusion criteria, that are specifically designed to investigate psychotropic changes are more likely to produce results that inform clinical practice and direct future research.

Psychiatric symptomatologies and disorders related to epilepsy and antiepileptic medications

INTRODUCTION

Psychiatric comorbidities (such as depression, anxiety, psychosis, inattention, obsession, personality traits, aggression and suicide) are frequent in patients with epilepsy and have a significant impact on medical management and quality of life.

AREAS COVERED

A literature search was performed in MEDLINE for epidemiological, longitudinal, prospective, double-blind clinical trial studies published between 1990 and 2011 using the following words: epilepsy, antiepileptic drugs (AEDs), behavioral/emotional/psychiatric comorbidities, suicide and aggression. In this review, the author discusses: i) the characterization and prevalence of behavioral disturbances associated with epilepsy, ii) variables correlated with behavioral comorbidities which include: psychosocial-, clinical- and treatment-related variables, iii) the complex mechanisms of behavioral comorbidities associated with epilepsy, which include both psychosocial (functional) and organic; the process of epileptogenesis, neuronal plasticity, abnormalities in hypothalamic-pituitary axis and neurotransmitters and pathways are fundamental determinants, iv) the negative psychotropic effects of AEDs and their mechanisms and v) the suggested biopsychosocial model of management (pharmacological and non-pharmacological).

EXPERT OPINION

The relationship between psychiatric disorders and epilepsy has relevant therapeutic implications which should be directed towards a comprehensive biopsychosocial approach that focuses on the whole person rather than simply on the disease process.

The new wave: time to bring EEG to the emergency department

Emergency electroencephalography (EEG) is indicated in the diagnosis and management of non-convulsive status epilepticus (NCSE) underlying an alteration in the level of consciousness. NCSE is a frequent, treatable, and under-diagnosed entity that can result in neurological injury. This justifies the need for EEG availability in the emergency department (ED). There is now emerging evidence for the potential benefits of EEG monitoring in various acute conditions commonly encountered in the ED, including convulsive status after treatment, breakthrough seizures in chronic epilepsy patients who are otherwise controlled, acute head trauma, and pseudo seizures. However, attempts to allow for routine EEG monitoring in the ED face numerous obstacles. The main hurdles to an optimized use of EEG in the ED are lack of space, the high cost of EEG machines, difficulty of finding time, as well as the expertise needed to apply electrodes, use the machines, and interpret the recordings. We reviewed the necessity for EEGs in the ED, and to meet the need, we envision a product that is comprised of an inexpensive single-use kit used to wirelessly collect and send EEG data to a local and/or remote neurologist and obtain an interpretation for managing an ED patient.

Acoustic effects of lamotrigine in pediatric patients with epilepsy

The aim of this study was to investigate the acoustic effects of lamotrigine in pediatric epileptic patients. Newly diagnosed 52 pediatric epileptic patients were assessed standard speech test through a Computerized Speech Lab applied before the beginning of therapy with lamotrigine and 2months after dosage had been stabilized. The voice onset times for /t/, /k(h)/, /p'/ and /t'/ after the therapy and those for /p/, /k/, /p(h)/, /t(h)/ and /k'/ was not affected. Total durations for all stop consonants did not change significantly except that lenis /p/ and /k/ increased significantly (P<0.05). No noteworthy alteration was observed for mean pitch and speaking rate of counting 1-10. Vowel formants and precise articulation rate remained the same. In conclusion, no significant effects of lamotrigine on speech were found in this study. Lamotrigine is safe for acoustic function in pediatric patients.

Consensus statement: the evaluation and treatment of people with epilepsy and affective disorders

Affective disorders in people with epilepsy (PWE) have become increasingly recognized as a primary factor in the morbidity and mortality of epilepsy. To improve the recognition and treatment of affective disorders in PWE, an expert panel comprising members from the Epilepsy Foundation's Mood Disorders Initiative have composed a Consensus Statement. This document focuses on depressive disorders in particular and reviews the appearance and treatment of the disorder in children, adolescents, and adults. Idiosyncratic aspects of the appearance of depression in this population, along with physiological and cognitive issues and barriers to treatment, are reviewed. Finally, a suggested approach to the diagnosis of affective disorders in PWE is presented in detail. This includes the use of psychometric tools for diagnosis and a stepwise algorithmic approach to treatment. Recommendations are based on the general depression literature as well as epilepsy-specific studies. It is hoped that this document will improve the overall detection and subsequent treatment of affective illnesses in PWE.

Expression of muscarinic and dopaminergic receptors and monoamine levels frontal cortex of epileptic rats

Apart from stroke, epilepsy is the most common neurological disorder with 0.5% of prevalence. The present study was performed in order to determine the monoamine levels, (M(1)-like) muscarinic and (D(1)- and D(2)-like) dopaminergic receptor changes in frontal cortex of adult rats after pilocarpine-induced status epilepticus (SE). Male Wistar rats were treated with a single dose of pilocarpine (400 mg/kg, s.c.) and the control group received 0.9% saline (s.c.). Both groups were sacrificed 1 h after treatment. The frontal cortex was dissected for neurochemical assays. The results show a downregulation of 27% in M(1) muscarinic receptor density, but in the dissociation constant (K(d)) value remained unaltered. D(1) and D(2) dopaminergic receptor densities and their K(d) values remained unaltered. Monoamine and metabolites levels presented decreases of 44%, 27%, 30% and 42% in dopamine (DA), homovanilic acid (HVA), norepinephrine (NE) and 5-hydroxyindoleacetic acid (5-HIAA) contents, respectively. Moreover, in serotonin (5-HT) level remained unaltered and the 4-hydroxy-3-methoxy-phenylacetic acid (DOPAC) concentration was augmented by 34%. The results suggest that dopaminergic system in this area studied may not be directly involved in the seizures and status epilepticus, but different monoamines and metabolites can be modified in this cerebral area during seizure process. In conclusion, the neurochemical alterations that occur in frontal cortex of adult rats observed during the establishment of the status epilepticus induced by pilocarpine are decrease in M(1) receptor density concentration and a reduction in DA and NE levels.