Bipolar disorder and epilepsy: a bidirectional relation? Neurobiological underpinnings, current hypotheses, and future research directions

The neuropsychological presentation of women with epilepsy: Clinical considerations and future directions

Objective: Cognitive, mood, and behavioral changes are common among persons with epilepsy (PWE), resulting in a complex neuropsychological presentation. Women with epilepsy (WWE) represent a distinct cohort within the broader epilepsy population due to sex and gender-specific factors impacting epilepsy semiology and treatment. However, unique neuropsychological profiles among WWE have not been established. This narrative review aims to further define neuropsychological correlates in WWE and promote meaningful discussion related to enhancing the provision of neuropsychological care within this clinical population. Method: Current literature in PWE examining differences in cognitive function, mental health, and quality of life (QoL) between women and men was critically reviewed, emphasizing considerations for neuropsychological practice. Results: WWE demonstrate a preservation of verbal learning and memory compared to men both pre- and post-surgically, with sex-based, neurobiological mechanisms likely contributing to this association. WWE also have elevated risk for affective disorder psychopathology, suicidality, and traumatic experiences. Epidemiology related to psychotic and bipolar spectrum disorders is less clear, and findings are mixed regarding sex-specific behavioral side effects of antiseizure and psychotropic medication. Finally, hormonal and obstetric factors are highlighted as important contributors to neuropsychological symptoms in WWE, with elevated risk for low QoL and increased stigma associated with greater medical and psychiatric comorbidities compared to men. Conclusions: While emerging literature has begun to characterize the neuropsychological presentation of WWE, future research is needed to define sex and gender differences in neuropsychological sequalae among PWE to ensure consistency and quality of care for WWE.

Sleep, mood disorders, and the ketogenic diet: potential therapeutic targets for bipolar disorder and schizophrenia

Bipolar disorder and schizophrenia are serious psychiatric conditions that cause a significant reduction in quality of life and shortened life expectancy. Treatments including medications and psychosocial support exist, but many people with these disorders still struggle to participate in society and some are resistant to current therapies. Although the exact pathophysiology of bipolar disorder and schizophrenia remains unclear, increasing evidence supports the role of oxidative stress and redox dysregulation as underlying mechanisms. Oxidative stress is an imbalance between the production of reactive oxygen species generated by metabolic processes and antioxidant systems that can cause damage to lipids, proteins, and DNA. Sleep is a critical regulator of metabolic homeostasis and oxidative stress. Disruption of sleep and circadian rhythms contribute to the onset and progression of bipolar disorder and schizophrenia and these disorders often coexist with sleep disorders. Furthermore, sleep deprivation has been associated with increased oxidative stress and worsening mood symptoms. Dysfunctional brain metabolism can be improved by fatty acid derived ketones as the brain readily uses both ketones and glucose as fuel. Ketones have been helpful in many neurological disorders including epilepsy and Alzheimer's disease. Recent clinical trials using the ketogenic diet suggest positive improvement in symptoms for bipolar disorder and schizophrenia as well. The improvement in psychiatric symptoms from the ketogenic diet is thought to be linked, in part, to restoration of mitochondrial function. These findings encourage further randomized controlled clinical trials, as well as biochemical and mechanistic investigation into the role of metabolism and sleep in psychiatric disorders. This narrative review seeks to clarify the intricate relationship between brain metabolism, sleep, and psychiatric disorders. The review will delve into the initial promising effects of the ketogenic diet on mood stability, examining evidence from both human and animal models of bipolar disorder and schizophrenia. The article concludes with a summary of the current state of affairs and encouragement for future research focused on the role of metabolism and sleep in mood disorders.

Abnormal patterns of sleep and waking behaviors are accompanied by neocortical oscillation disturbances in an Ank3 mouse model of epilepsy-bipolar disorder comorbidity

ANK3 is a leading bipolar disorder (BD) candidate gene in humans and provides a unique opportunity for studying epilepsy-BD comorbidity. Previous studies showed that deletion of Ank3-1b, a BD-associated variant of Ank3 in mice leads to increased firing threshold and diminished action potential dynamic range of parvalbumin (PV) interneurons and absence epilepsy, thus providing a biological mechanism linking epilepsy and BD. To explore the behavioral overlap of these disorders, we characterized behavioral patterns of Ank3-1b KO mice during overnight home-cage activity and examined network activity during these behaviors using paired video and EEG recordings. Since PV interneurons contribute to the generation of high-frequency gamma oscillations, we anticipated changes in the power of neocortical EEG signals in the gamma frequency range (> 25 Hz) during behavioral states related to human BD symptoms, including abnormal sleep, hyperactivity, and repetitive behaviors. Ank3-1b KO mice exhibited an overall increase in slow gamma (~25-45 Hz) power compared to controls, and slow gamma power correlated with seizure phenotype severity across behaviors. During sleep, increased slow gamma power correlated with decreased time spent in the rapid eye movement (REM) stage of sleep. Seizures were more common during REM sleep compared to non-REM (NREM) sleep. We also found that Ank3-1b KO mice were hyperactive and exhibited a repetitive behavior phenotype that co-occurred with increased slow gamma power. Our results identify a novel EEG biomarker associating Ank3 genetic variation with BD and epilepsy and suggest modulation of gamma oscillations as a potential therapeutic target.

Bipolar mania and epilepsy pathophysiology and treatment may converge in purine metabolism: A new perspective on available evidence

Decreased ATPergic signaling is an increasingly recognized pathophysiology in bipolar mania disease models. In parallel, adenosine deficit is increasingly recognized in epilepsy pathophysiology. Under-recognized ATP and/or adenosine-increasing mechanisms of several antimanic and antiseizure therapies including lithium, valproate, carbamazepine, and ECT suggest a fundamental pathogenic role of adenosine deficit in bipolar mania to match the established role of adenosine deficit in epilepsy. The depletion of adenosine-derivatives within the purine cycle is expected to result in a compensatory increase in oxopurines (uric acid precursors) and secondarily increased uric acid, observed in both bipolar mania and epilepsy. Cortisol-based inhibition of purine conversion to adenosine-derivatives may be reflected in observed uric acid increases and the well-established contribution of cortisol to both bipolar mania and epilepsy pathology. Cortisol-inhibited conversion from IMP to AMP as precursor of both ATP and adenosine may represent a mechanism for treatment resistance common in both bipolar mania and epilepsy. Anti-cortisol therapies may therefore augment other treatments both in bipolar mania and epilepsy. Evidence linking (i) adenosine deficit with a decreased need for sleep, (ii) IMP/cGMP excess with compulsive hypersexuality, and (iii) guanosine excess with grandiose delusions may converge to suggest a novel theory of bipolar mania as a condition characterized by disrupted purine metabolism. The potential for disease-modification and prevention related to adenosine-mediated epigenetic changes in epilepsy may be mirrored in mania. Evaluating the purinergic effects of existing agents and validating purine dysregulation may improve diagnosis and treatment in bipolar mania and epilepsy and provide specific targets for drug development.

Interictal Dysphoric Disorder: A disorder with distinct nosography or atypical symptomatology of mood disorders in people with epilepsy? Results from a systematic review

INTRODUCTION

Mood disorders are the most frequent comorbidities in people with epilepsy. The term Interictal Dysphoric Disorder (IDD) has been used to describe a condition where at least three out of eight symptoms must be present for diagnosis. Symptoms are grouped into three symptom clusters of four "labile depressive" symptoms (anergia, depressed mood, insomnia, and pain), two "labile affective" symptoms (anxiety and fear), and two specific symptoms (euphoric moods and paroxysmal irritability), which are described and can be present in people with epilepsy. There is debate about whether IDD is a distinct disease, or if it is simply a special manifestation of mood disorders in epilepsy. For instance, it may represent an atypical presentation of depression in this population.

METHODS

We conducted a systematic review of the literature in 3 databases with the terms "Interictal Dysphoric Disorder" and "mood disorder". A total of 130 articles were selected and, after removing the duplicated applying eligibility criteria, 12 articles were included.

RESULTS

Six articles showed positive evidence for the validation of IDD as an independent nosological entity; in contrast, five articles reported inconclusive findings regarding the question; one explicitly questioned significant differences between IDD and mood disorders as nosological constructs. The data available and presented in this systematic review is insufficient to confirm IDD as a distinct diagnostic category. Nevertheless, it is worth noting other researchers have found some validity in this concept, highlighting the strong connection between mood disorders and epilepsy.

CONCLUSION

Further research in this area is needed, and additional systematic reviews focusing on other aspects of the construct, such as neurobiological mechanisms, may prove to be helpful.

Postictal psychosis, a cause of secondary affective psychosis: A clinical description study of 77 patients

OBJECTIVE

Postictal psychosis (PIP) is a severe complication occurring at least in 2% of patients with epilepsy. Since the 19th century, psychiatrists have reported the specificity of PIP presentation, but descriptions did not clearly distinguish PIP from after-seizure delirium. This study aimed to provide a precise description of psychiatric signs occurring during PIP, and improve recognition of PIP.

METHODS

We performed a review of clinical descriptions available in literature (48 patients), that we gathered with a retrospective multicentric case series of patients from three French epilepsy units (29 patients). For each patient, we collected retrospectively the psychiatric signs, and epilepsy features.

RESULTS

We found a high prevalence of persecutory (67.5%) and religious (55.8%) delusions, with almost systematic hallucinations (83.1%) and frequent mood disturbances (76.6%), especially euphoria. Severe consequences were not negligible (other-directed assault in 20.8%, self-directed in 13.0%). The type of delusion was associated with mood symptoms (p = 0.017). Episode onset was mainly sudden/rapid (90.9%), its duration was mostly between one and 14 days (64.9%) and the response to antipsychotic medication was good. Disorder was recurrent in more than a half of the sample (57.1% of patients with at least 2 episodes).

CONCLUSION

Considering our findings, PIP resembles more an affective psychosis, than a purely psychotic disorder. The presence of affective signs differentiates PIP from other psychotic comorbidities in epilepsy. Additionally, resemblance between PIP and psychotic manic episode might help to discuss links between epilepsy and bipolar disorder.

Ouabain inhibitor rostafuroxin attenuates dextromethorphan-induced manic potential

Dextromethorphan (DM) abuse produces mania-like symptoms in humans. ERK/Akt signaling activation involved in manic potential can be attenuated by the inhibition of ouabain-like cardiac steroids. In this study, increased phosphorylations of ERK/Akt and hyperlocomotion induced by DM (30 mg/kg, i.p./day × 7) were significantly protected by the ouabain inhibitor rostafuroxin (ROSTA), suggesting that DM induces the manic potential. ROSTA significantly attenuated DM-induced protein kinase C δ (PKCδ) phosphorylation, GluN2B (i.e., MDA receptor subunit) expression, and phospho-PKCδ/GluN2B interaction. DM instantly upregulated the nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent system. However, DM reduced Nrf2 nuclear translocation, Nrf2 DNA binding activity, γ-glutamylcysteine mRNA expression, and subsequent GSH/GSSG level and enhanced oxidative parameters following 1-h of administration. ROSTA, PKCδ inhibitor rottlerin, and GluN2B inhibitor traxoprodil significantly attenuated DM-induced alterations in Nrf2-related redox parameters and locomotor activity induced by DM in wild-type mice. Importantly, in PKCδ knockout mice, DM failed to alter the above parameters. Further, ROSTA and traxoprodil also failed to enhance PKCδ depletion effect, suggesting that PKCδ is a critical target for the anti-manic potential of ROSTA or GluN2B antagonism. Our results suggest that ROSTA inhibits DM-induced manic potential by attenuating ERK/Akt activation, GluN2B/PKCδ signalings, and Nrf2-dependent system.

Women's issues

Special considerations are required for women with epilepsy. These include issues such as catamenial exacerbation, concerns for contraception, teratogenesis (including both anatomical and neurodevelopmental effects), and other concerns for pregnancy complications such as increased seizures or adverse obstetric outcomes. In this manuscript, several cases are presented and discussed addressing some of the important issues in the management of women with epilepsy.

Prolonged functional cerebral asymmetry as a consequence of dysfunctional parvocellular paraventricular hypothalamic nucleus signaling: An integrative model for the pathophysiology of bipolar disorder

Approximately 45 million people worldwide are diagnosed with bipolar disorder (BD). While there are many known risk factors and models of the pathologic processes influencing BD, the exact neurologic underpinnings of BD are unknown. We attempt to integrate the existing literature and create a unifying hypothesis regarding the pathophysiology of BD with the hope that a concrete model may potentially facilitate more specific diagnosis, prevention, and treatment of BD in the future. We hypothesize that dysfunctional signaling from the parvocellular neurons of the paraventricular hypothalamic nucleus (PVN) results in the clinical presentation of BD. Functional damage to this nucleus and its signaling pathways may be mediated by myriad factors (e.g. immune dysregulation and auto-immune processes, polygenetic variation, dysfunctional interhemispheric connections, and impaired or overactivated hypothalamic axes) which could help explain the wide variety of clinical presentations along the BD spectrum. The neurons of the PVN regulate ultradian rhythms, which are observed in cyclic variations in healthy individuals, and mediate changes in functional hemispheric lateralization. Theoretically, dysfunctional PVN signaling results in prolonged functional hemispheric dominance. In this model, prolonged right hemispheric dominance leads to depressive symptoms, whereas left hemispheric dominance correlated to the clinical picture of mania. Subsequently, physiologic processes that increase signaling through the PVN (hypothalamic-pituitaryadrenal axis, hypothalamic- pituitary-gonadal axis, and hypothalamic-pituitary-thyroid axis activity, suprachiasmatic nucleus pathways) as well as, neuro-endocrine induced excito-toxicity, auto-immune and inflammatory flairs may induce mood episodes in susceptible individuals. Potentially, ultradian rhythms slowing with age, in combination with changes in hypothalamic axes and maturation of neural circuitry, accounts for BD clinically presenting more frequently in young adulthood than later in life.

Psychopathological features in referred adolescents with psychogenic nonepileptic seizures with or without epilepsy

Psychogenic nonepileptic seizures (PNES) are episodic manifestations that mimic epileptic seizures (ES) although not associated with electroencephalogram (EEG) abnormalities. Psychogenic nonepileptic seizures and ES, however, can often cooccur. Emotional distress in adolescents can trigger PNES, but the psychopathological and personality features are still unknown. The aim of this study was to explore psychopathological features in a sample of referred youth with PNES, with or without ES, compared with a control group with ES. Thirty-four patients aged 12 to 21 years, 19 females and 15 males, were included in the study, 15 patients with PNES, 7 with PNES and ES, and 12 with ES. The three groups were compared according to psychiatric categorical diagnoses, psychopathological dimensions, life stressors, and personality traits, including alexithymia, interpersonal reactivity, and resilience, all assessed with structured measures. Patients with PNES, with or without ES, were more severely impaired, had a higher incidence of mood disorders, more frequent lifetime traumatic experiences, and lower resilience. All the three groups presented alexythimic traits and emotional dysregulation. Major limitations are the small sample size and the lack of a control group of healthy subjects. Disentagling psychopathological characteristics in PNES can help clinicians to focus diagnostic approaches and therapeutic interventions.

A pyruvate dehydrogenase complex disorder hypothesis for bipolar disorder

Ketosis is a metabolic state in which the body uses ketones derived from breakdown of fatty acids as the primary mitochondrial fuel source instead of glucose. In recent years an accumulation of evidence for the beneficial effects of the ketotic state on the brain have heightened interest in its potential for use in neurological conditions. The ketogenic diet (KD) induces ketosis and is an effective treatment for medically resistant epilepsy. There is significant comorbidity between epilepsy and bipolar disorder (BD) and both conditions are treated by anti-convulsant drugs. In addition, reports on bipolar disease online fora have highlighted subjective mood stabilization effects associated with the KD. These KD reported effects could be explained if there was a disorder in the conversion of pyruvate into Acetyl-CoA (and subsequent impairment of oxidative phosphorylation) which was bypassed by ketones providing an alternative substrate for oxidative phosphorylation. This is consistent with growing evidence that mitochondrial dysfunction plays a causal role in BD and explains the reported TCA cycle dysfunction and elevated pyruvate levels in BD. Reduced levels of ATP affects the normal operation of the Na, K-ATPase in the brain with differing levels of reduction either leading to reduced neuronal action potential and inhibition of neurotransmitter release (consistent with the depressed state in BD) or increased neuronal resting potential and hyper-excitability (consistent with a [hypo]manic mood state). We hypothesize that the mitochondrial dysfunction is due to a disorder of the Pyruvate Dehydrogenase Complex (PDC) and/or Mitochondrial Carrier Protein (MCP) shuttle which moves intracellular pyruvate into mitochondria. The resultant reduction in ATP generation could explain mood instability and cycling in BD (through mechanisms such as those delineated by Mallakh and Peters). This proposed novel causal pathway could explain mood de-stabilization in BD and the reported positive effects of KD. If true, this hypothesis would suggest that there should be increased research attention to PDC (and in particular the E1 alpha subunit) as potential therapeutic targets and further study of a possible role of KD in BD to improve mood stability. Experimental approaches, such as through a clinical trial of KD on mood stabilization in BD, are required to further investigate this hypothesis.

Medical Comorbidities in Bipolar Disorder

PURPOSE OF REVIEW

Bipolar disorder (BD) medical comorbidity presents significant clinical and public health concerns with serious impact on health. The aim of this article is to present an updated narrative review of original research articles (case control, longitudinal cohort, and cross-sectional studies) and meta-analyses published in English language journals from January 2013 to May 2017 focusing on general medical comorbidity in BD, including the added risks of iatrogenic factors relevant to the treatment of BD.

RECENT FINDINGS

We found numerous patterns of association between BD and various medical disorders involving multiple organ systems. One pattern indicated reciprocal increase in the rate of each comorbid condition, such as an increased rate of BD in asthma or migraine, and likewise an increase in the rate of asthma or migraine in patients with BD. A second pattern was a predominantly unidirectional increase in the rate of BD in patients with certain medical disorders, such as multiple sclerosis or cerebellar diseases. A third pattern was a predominantly unidirectional increased rate of medical disorders in patients with BD. One study suggested the potential involvement of genetic mechanisms for the association between BD and migraine. Most of the studies had cross-sectional or retrospective designs, and many relied on analysis of large administrative databases inviting multiple potential biases. Our review highlights the association between BD and a variety of medical disorders. Further research is needed to elucidate the potential underlying etiopathological mechanisms that contribute to observed comorbidities. The results of this review also emphasize the need for comprehensive screening for medical disorders in BD and for adoption of an integrated model of care to address these complex comorbidities.

Precursors in adolescence of adult-onset bipolar disorder

BACKGROUND

Although the estimated contribution of genetic factors is high in bipolar disorder, environmental factors may also play a role. This Swedish register-based cohort study of men examined if physical and psychological characteristics in late adolescence, including factors previously linked with bipolar disorder (body mass index, asthma and allergy), are associated with subsequent bipolar disorder in adulthood. Unipolar depression and anxiety are analysed as additional outcomes to identify bipolar disorder-specific associations.

METHODS

A total of 213,693 men born between 1952 and 1956, who participated in compulsory military conscription assessments in late adolescence were followed up to 2009, excluding men with any psychiatric diagnoses at baseline. Cox regression estimated risk of bipolar disorder, depression and anxiety in adulthood associated with body mass index, asthma, allergy, muscular strength stress resilience and cognitive function in adolescence.

RESULTS

BMI, asthma and allergy were not associated with bipolar disorder. Higher grip strength, cognitive function and stress resilience were associated with a reduced risk of bipolar disorder and the other disease outcomes.

LIMITATIONS

The sample consisted only of men; even though the characteristics in adolescence pre-dated disease onset, they may have been the consequence of prodromal disease.

CONCLUSIONS

Associations with body mass index and asthma found by previous studies may be consequences of bipolar disorder or its treatment rather than risk factors. Inverse associations with all the outcome diagnoses for stress resilience, muscular strength and cognitive function may reflect general risks for these psychiatric disorders or intermediary factors.

Is Mania the Hypertension of the Mood? Discussion of A Hypothesis

Beyond both being biphasic/bidirectional disorders (hypo)mania and essential hypertension share a surprising number of similarities and an overlap between their genetics, biological background, underlying personality and temperamental factors, precipitating factors, comorbidity and response to treatment, indicating a possibly partially shared biological background. Based on theoretical knowledge, similarities related to characteristics, manifestation and course, and the results of pharmacological studies related to the effects and side effects of pharmacotherapies used in the treatment of these two distinct disorders, the authors outline a hypothesis discussing the similar origins of these two phenomena and thus mania being the hypertension of mood in memory of Athanasios Koukopoulos, one of the greatest researchers and theoreticists of mania of all time.

Systematic Review of Cognitive Function in Euthymic Bipolar Disorder and Pre-Surgical Temporal Lobe Epilepsy

BACKGROUND

Bipolar disorder (BD) and temporal lobe epilepsy (TLE) overlap in domains including epidemiology, treatment response, shared neurotransmitter involvement and temporal lobe pathology. Comparison of cognitive function in both disorders may indicate temporal lobe mediated processes relevant to BD. This systematic review examines neuropsychological test profiles in euthymic bipolar disorder type I (BD-I) and pre-surgical TLE and compares experimental designs used.

METHODS

A search of PubMed, PsychINFO, and Scopus using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted. Inclusion criteria were comparison group or pre- to post-surgical patients; reported neuropsychological tests; participants aged 18-60 years. Fifty six studies met criteria: 27 BD-I; 29 TLE.

RESULTS

Deficits in BD-I compared to healthy controls (HC) were in executive function, attention span and verbal memory. Deficits in TLE compared to HC were in executive function and memory. In the pre- to post-surgical comparisons, verbal memory in left temporal lobe (LTL) and, less consistently, visuospatial memory in right temporal lobe (RTL) epilepsy declined following surgery. BD-I studies used comprehensive test batteries in well-defined euthymic patients compared to matched HC groups. TLE studies used convenience samples pre- to post-surgery, comparing LTL and RTL subgroups, few included comparisons to HC (5 studies). TLE studies typically examined a narrow range of known temporal lobe-mediated neuropsychological functions, particularly verbal and visuospatial memory.

CONCLUSION

Both disorders exhibit deficits in executive function and verbal memory suggestive of both frontal and temporal lobe involvement. However, deficits in TLE are measured pre- to post-surgery and not controlled at baseline pre-surgery. Further research involving a head-to-head comparison of the two disorders on a broad range of neuropsychological tests is needed to clarify the nature and extent of cognitive deficits and potential overlaps.

Mood Disorders in Epilepsy

Mood disorders associated with epilepsy are very common and overrepresented compared with other chronic medical conditions. Depression is a particularly common and worrisome comorbidity, especially because suicidality seems to be increased significantly in the context of epilepsy. Although psychosocial stressors commonly are associated, intrinsic characteristics of seizure disorders may contribute to the expression of depressive symptoms. Depression and epilepsy may exacerbate each other. Epilepsy with seizure foci in the temporal lobe may represent a higher risk of developing depression, especially if the seizures do not generalize. Treatment of depression is multifaceted and includes psychotherapy and sophisticated regimens of anticonvulsants. Most antidepressants may be used safely and effectively in the context of depression, although high-quality evidence is lacking. Ultimately, treatment of comorbid mood disorder has important implications for outcome and quality of life, perhaps even more than treatment of epilepsy itself.

Insights into the Pathology of the α3 Na(+)/K(+)-ATPase Ion Pump in Neurological Disorders; Lessons from Animal Models

The transmembrane Na(+)-/K(+) ATPase is located at the plasma membrane of all mammalian cells. The Na(+)-/K(+) ATPase utilizes energy from ATP hydrolysis to extrude three Na(+) cations and import two K(+) cations into the cell. The minimum constellation for an active Na(+)-/K(+) ATPase is one alpha (α) and one beta (β) subunit. Mammals express four α isoforms (α1-4), encoded by the ATP1A1-4 genes, respectively. The α1 isoform is ubiquitously expressed in the adult central nervous system (CNS) whereas α2 primarily is expressed in astrocytes and α3 in neurons. Na(+) and K(+) are the principal ions involved in action potential propagation during neuronal depolarization. The α1 and α3 Na(+)-/K(+) ATPases are therefore prime candidates for restoring neuronal membrane potential after depolarization and for maintaining neuronal excitability. The α3 isoform has approximately four-fold lower Na(+) affinity compared to α1 and is specifically required for rapid restoration of large transient increases in [Na(+)]i. Conditions associated with α3 deficiency are therefore likely aggravated by suprathreshold neuronal activity. The α3 isoform been suggested to support re-uptake of neurotransmitters. These processes are required for normal brain activity, and in fact autosomal dominant de novo mutations in ATP1A3 encoding the α3 isoform has been found to cause the three neurological diseases Rapid Onset Dystonia Parkinsonism (RDP), Alternating Hemiplegia of Childhood (AHC), and Cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS). All three diseases cause acute onset of neurological symptoms, but the predominant neurological manifestations differ with particularly early onset of hemiplegic/dystonic episodes and mental decline in AHC, ataxic encephalopathy and impairment of vision and hearing in CAPOS syndrome and late onset of dystonia/parkinsonism in RDP. Several mouse models have been generated to study the in vivo consequences of Atp1a3 modulation. The different mice show varying degrees of hyperactivity, gait problems, and learning disability as well as stress-induced seizures. With the advent of several Atp1a3-gene or chemically modified animal models that closely phenocopy many aspects of the human disorders, we will be able to reach a much better understanding of the etiology of RDP, AHC, and CAPOS syndrome.

Parental and comorbid epilepsy in persons with bipolar disorder

BACKGROUND

Population-based studies have demonstrated an overrepresentation of bipolar disorder (BPD) in individuals with epilepsy. However, few studies have examined the reverse association, i.e. comorbid epilepsy in individuals selected based on BPD diagnosis. No previous population-based study having examined the co-occurrence of BPD and epilepsy has adjusted for parental psychopathology. Such an adjustment is motivated by population-based studies reporting an overrepresentation of various types of parental psychiatric disorders in both BPD and epilepsy. Furthermore, an association between epilepsy in first-degree relatives and BPD has previously only been examined and demonstrated in a small clinical sample. The objective of this study is to examine the associations between parental and comorbid epilepsy and BPD, adjusting for parental psychopathology.

METHODS

This nested case-control study identified 1861 cases with BPD, age up to 25 years, 3643 matched controls, and their parents from Finnish national registers. Conditional logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) and two-sided significance limits of p<0.05.

RESULTS

BPD was associated with comorbid epilepsy (adjusted OR 2.53, 95% CI: 1.73-3.70) but not with parental epilepsy. Epilepsy was found in 3.33% of cases versus 1.29% of controls, 2.69% of cases' parents versus 2.53% of controls' parents.

LIMITATIONS

The diagnoses were register-based, not based on standardized procedures with direct ascertainment.

CONCLUSIONS

An association between BPD and comorbid epilepsy persists even after adjusting for parental psychopathology. Lack of familial clustering of BPD and epilepsy would suggest that the elevated co-occurrence of these disorders is influenced by non-genetic factors.

Epilepsy and bipolar disorder

It is well recognized that mood disorders and epilepsy commonly co-occur. Despite this, our knowledge regarding the relationship between epilepsy and bipolar disorder is limited. Several shared features between the two disorders, such as their episodic nature and potential to run a chronic course, and the efficacy of some antiepileptic medications in the prophylaxis of both disorders, are often cited as evidence of possible shared underlying pathophysiology. The present paper aims to review the bidirectional associations between epilepsy and bipolar disorder, with a focus on epidemiological links, evidence for shared etiology, and the impact of these disorders on both the individual and wider society. Better recognition and understanding of these two complex disorders, along with an integrated clinical approach, are crucial for improved evaluation and management of comorbid epilepsy and mood disorders.

Pachygyria Presented as Mania

Psychiatric manifestation of pachygyria, a neuronal migration disorder is rare in literature; rarer if it is bipolar disorder specifically. Here, we report a case of mania and seizure who subsequently diagnosed as pachygyria. Proper literature about pathophysiology is discussed and recently discovered putative genetic role in bipolar disorder explained. This case also emphasis the importance of detailed history taking and imaging investigation even in a pure psychiatric presentation.

Comparison of precipitating factors for mania and partial seizures: Indicative of shared pathophysiology?

OBJECTIVES

Mania in bipolar disorder (BD) and partial (focal) seizures (PS) arising from the temporal lobes, have a number of similarities. Typically, a chronic course of the disorders is punctuated by acute illness episodes. Common features of episodes may include sensory, perceptual, cognitive and affective changes. Both respond to anticonvulsant treatment. Common mechanisms imputed include neurotransmitters and kindling processes. Further investigation may improve understanding of the occurrence of both mania and PS, casting light on the relevance of temporal lobe mediated processes and pathology. One avenue of investigation is to compare aetiological factors and determine the extent of overlap which may indicate shared brain localization or pathophysiology. Aetiology includes predisposing, precipitating or perpetuating factors. This paper examines the literature on precipitating factors of mania, first or subsequent episode, and of PS in diagnosed epilepsy, which is the second or subsequent seizure, to identify the extent and nature of their overlap.

METHOD

Narrative review based on a literature search of PubMed and Google Scholar.

RESULTS

Precipitating factors for both mania and PS were stress, sleep deprivation, antidepressant medication and, tentatively, emotion. For mania alone, goal-attainment events, spring and summer season, postpartum, and drugs include steroids and stimulants. For PS alone, winter season, menstruation and specific triggers in complex reflex epilepsies. Those not substantiated include lunar phase and menopause. A wide range of chemicals may provoke isolated seizures but by definition epilepsy requires at least two seizures.

CONCLUSIONS

The overlap of precipitating factors in mania and PS imply that common brain processes may contribute to both, consistent with findings from neuroscience research.

Comorbid medical illness in bipolar disorder

BACKGROUND

Individuals with a mental health disorder appear to be at increased risk of medical illness.

AIMS

To examine rates of medical illnesses in patients with bipolar disorder (n = 1720) and to examine the clinical course of the bipolar illness according to lifetime medical illness burden.

METHOD

Participants recruited within the UK were asked about the lifetime occurrence of 20 medical illnesses, interviewed using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) and diagnosed according to DSM-IV criteria.

RESULTS

We found significantly increased rates of several medical illnesses in our bipolar sample. A high medical illness burden was associated with a history of anxiety disorder, rapid cycling mood episodes, suicide attempts and mood episodes with a typically acute onset.

CONCLUSIONS

Bipolar disorder is associated with high rates of medical illness. This comorbidity needs to be taken into account by services in order to improve outcomes for patients with bipolar disorder and also in research investigating the aetiology of affective disorder where shared biological pathways may play a role.

Affective temperament profiles and clinical correlates in patients with epilepsy: a link from mood disorders

BACKGROUND

The current study sought to investigate the affective temperaments of patients with epilepsy and possible relationships between disease characteristics and temperament profiles.

METHODS

A total of 70 adults with epilepsy and 70 healthy volunteers completed the Beck Depression Inventory (BDI), the Beck Anxiety Inventory and the Temperament Evaluation of Memphis, Pisa, Paris and San Diego (TEMPS-A).

RESULTS

Patients with epilepsy had higher scores on these three scales than healthy controls. With respect to temperaments, irritable temperament alone was significantly higher in patients than controls. Irritable temperament also had a significant positive correlation with psychiatric history, whereas depressive temperament had a significant positive correlation with illness and treatment duration. Patients who had suffered simple partial and complex partial seizures had higher anxious temperament scores than patients with generalized epilepsy.

LIMITATIONS

Because the study group was recruited through consecutive patients seen in a single neurology clinic, our findings may not be representative of PWE in general.

CONCLUSIONS

Because irritability is one of the key symptoms of interictal dysphoric disorder and because TEMPS-A irritable temperament and BDI scores were found to be significantly related, the high rate of irritable temperament in our patient sample may be associated with depressive mood. We may suggest that at least some of the affective symptoms in patients with epilepsy and the historical concept of "epileptic personality" may be explained by affective temperaments.

An investigation into the relationship between first-degree relatives of bipolar affective disorder and (idiopathic) epilepsy in a sub-Saharan African population

OBJECTIVE

Phenomenological, neuro-biological and pharmacological investigations linked bipolar affective disorders with epilepsy. Similarly, a large community-based epidemiological study of epileptic patients reported that 12% of the participants had bipolar symptoms, a rate 7× higher than in control. Bipolar and epileptic disorders are epiphenomena of an underlying genetic susceptibility. This study aimed to determine the relationship between first-degree relatives of bipolar and epileptic patients in a sub-Saharan African population.

METHOD

In this case-control study, we used a socio-demographic and clinical variables questionnaire to assess random convenient samples of 50 control, 40 and 60 first-degree relatives of bipolar and epileptic patients, respectively at Federal Neuro-psychiatric Hospital (FNPH), Maiduguri. Relatives of epileptic patients and the control completed the mood disorder questionnaire (MDQ). Two consultant psychiatrists made the diagnosis of epilepsy using the ILAE criteria, in relatives of bipolar patients and the control. Participants in both groups had no EEG. We analysed the data obtained, using EPI-info 7 to report averages and associations between categorical variables with Chi-square test, and analysis of variance (ANOVA) for parametric data(statistical significance set at p=0.5, two-tailed).

RESULTS

The rate of epilepsy among relatives of bipolar disorder compared with control was 15.2% vs. 2.0% (χ(2)=46.08, p<0.001), and that of bipolar among relatives of epileptics compared with control was 14.5% vs. 2.1% (χ(2)=31.2, p<0.001). Educational status showed significant relationship across two groups (χ(2)=24.19, p=0.0001). Using ANOVA, age showed significant relationship among relatives of bipolar and epileptic patients (F=5.769, p=0.0039).

CONCLUSION

Despite its limitations, this preliminary study contributes to literature on the relationship between epilepsy and bipolar affective disorder in sub-Saharan Africa.

A review of potassium channels in bipolar disorder

Although bipolar disorder (BP) is one of the most heritable psychiatric conditions, susceptibility genes for the disorder have yet to be conclusively identified. It is likely that variants in multiple genes across multiple pathways contribute to the genotype–phenotype relationship in the affected population. Recent evidence from genome-wide association studies implicates an entire class of genes related to the structure and regulation of ion channels, suggesting that the etiology of BP may arise from channelopathies. In this review, we examine the evidence for this hypothesis, with a focus on the potential role of voltage-gated potassium channels. We consider evidence from genetic and expression studies, and discuss the potential underlying biology. We consider animal models and treatment implications of the involvement of potassium ion channelopathy in BP. Finally, we explore intriguing parallels between BP and epilepsy, the signature channelopathy of the central nervous system.

Incorporating Information of microRNAs into Pathway Analysis in a Genome-Wide Association Study of Bipolar Disorder

MicroRNAs (miRNAs) are known to be important post-transcriptional regulators that are involved in the etiology of complex psychiatric traits. The present study aimed to incorporate miRNAs information into pathway analysis using a genome-wide association dataset to identify relevant biological pathways for bipolar disorder (BPD). We selected psychiatric- and neurological-associated miRNAs (N = 157) from PhenomiR database. The miRNA target genes (miTG) predictions were obtained from microRNA.org. Canonical pathways (N = 4,051) were downloaded from the Molecule Signature Database. We employed a novel weighting scheme for miTGs in pathway analysis using methods of gene set enrichment analysis and sum-statistic. Under four statistical scenarios, 38 significantly enriched pathways (P-value < 0.01 after multiple testing correction) were identified for the risk of developing BPD, including pathways of ion channels associated (e.g., gated channel activity, ion transmembrane transporter activity, and ion channel activity) and nervous related biological processes (e.g., nervous system development, cytoskeleton, and neuroactive ligand receptor interaction). Among them, 19 were identified only when the weighting scheme was applied. Many miRNA-targeted genes were functionally related to ion channels, collagen, and axonal growth and guidance that have been suggested to be associated with BPD previously. Some of these genes are linked to the regulation of miRNA machinery in the literature. Our findings provide support for the potential involvement of miRNAs in the psychopathology of BPD. Further investigations to elucidate the functions and mechanisms of identified candidate pathways are needed.

Differential expression of genes encoding neuronal ion-channel subunits in major depression, bipolar disorder and schizophrenia: implications for pathophysiology

Evidence concerning ion-channel abnormalities in the pathophysiology of common psychiatric disorders is still limited. Given the significance of ion channels in neuronal activity, neurotransmission and neuronal plasticity we hypothesized that the expression patterns of genes encoding different ion channels may be altered in schizophrenia, bipolar and unipolar disorders. Frozen samples of striatum including the nucleus accumbens (Str-NAc) and the lateral cerebellar hemisphere of 60 brains from depressed (MDD), bipolar (BD), schizophrenic and normal subjects, obtained from the Stanley Foundation Brain Collection, were assayed. mRNA of 72 different ion-channel subunits were determined by qRT-PCR and alteration in four genes were verified by immunoblotting. In the Str-NAc the prominent change was observed in the MDD group, in which there was a significant up-regulation in genes encoding voltage-gated potassium-channel subunits. However, in the lateral cerebellar hemisphere (cerebellum), the main change was observed in schizophrenia specimens, as multiple genes encoding various ion-channel subunits were significantly down-regulated. The impaired expression of genes encoding ion channels demonstrates a disease-related neuroanatomical pattern. The alterations observed in Str-NAc of MDD may imply electrical hypo-activity of this region that could be of relevance to MDD symptoms and treatment. The robust unidirectional alteration of both excitatory and inhibitory ion channels in the cerebellum may suggests cerebellar general hypo-transcriptional activity in schizophrenia.

Mania-like behavior induced by genetic dysfunction of the neuron-specific Na+,K+-ATPase α3 sodium pump

Bipolar disorder is a debilitating psychopathology with unknown etiology. Accumulating evidence suggests the possible involvement of Na(+),K(+)-ATPase dysfunction in the pathophysiology of bipolar disorder. Here we show that Myshkin mice carrying an inactivating mutation in the neuron-specific Na(+),K(+)-ATPase α3 subunit display a behavioral profile remarkably similar to bipolar patients in the manic state. Myshkin mice show increased Ca(2+) signaling in cultured cortical neurons and phospho-activation of extracellular signal regulated kinase (ERK) and Akt in the hippocampus. The mood-stabilizing drugs lithium and valproic acid, specific ERK inhibitor SL327, rostafuroxin, and transgenic expression of a functional Na(+),K(+)-ATPase α3 protein rescue the mania-like phenotype of Myshkin mice. These findings establish Myshkin mice as a unique model of mania, reveal an important role for Na(+),K(+)-ATPase α3 in the control of mania-like behavior, and identify Na(+),K(+)-ATPase α3, its physiological regulators and downstream signal transduction pathways as putative targets for the design of new antimanic therapies.

Mania associated with complicated hereditary spastic paraparesis

Hereditary spastic paraparesis (HSP) is an inherited group of neurological disorders with progressive lower limb spasticity. HSP can be clinically grouped into pure and complicated forms. Pure HSP is one without any associated neurological/psychiatric comorbidity. Depression is the most common psychiatric comorbidity. Presence of mania or bipolar affective illness with HSP is a rare phenomenon. We report a case of a 17-year-old boy who presented with classical features of HSP with complaints of excessive happiness, irritability, increased self-esteem and decreased sleep since 1 month. The patient also had complex partial seizure ever since he had features of HSP. The patient's father and younger sister suffer from pure HSP. The patient was diagnosed to have first episode mania with complicated HSP. The details of treatment and possible neurobiology are discussed in this case report.

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.

Effect of levetiracetam on depression and anxiety in adult epileptic patients

BACKGROUND

Interictal depression is common in patients with epilepsy and it significantly impacts quality of life. Some studies indicate that levetiracetam (LEV) may have mood stabilizing properties.

METHODS

Twenty-five adults with uncontrolled partial seizures and concomitant depressive symptoms were treated with LEV. Patients were evaluated for depression and anxiety with several psychometric measures, including: Montgomery and Asberg Depression Rating Scale (MADRS), Hamilton Depression Rating Scale (HDRS), Zung Self-rating Scale for Depression (Z-SDS), Hamilton Anxiety Rating Scale (HARS), Zung Self-rating Scale for Anxiety (Z-SAS).

RESULTS

Evaluations after 5 weeks and after 3 months of LEV treatment demonstrated significant improvement in depression and anxiety.

CONCLUSIONS

This uncontrolled study suggests that treatment with LEV may also improve depression and anxiety in patients with partial seizures. However, the sample of patients is limited and the possibility of a placebo effect cannot be excluded. These findings must be considered preliminary and should be replicated under placebo-controlled conditions.