Valproic acid induced encephalopathy – 19 new cases in Germany from 1994 to 2003 – A side effect associated to VPA-therapy not only in young children

Hyperammonemic encephalopathy induced by valproic acid

Valproate (VPA) is broad-spectrum antiepileptic drug. Several adverse reactions including hepatotoxicity, fetal risk and pancreatitis are well known and labelled as boxed warnings in the USA. One adverse reaction that is less well known but clinically significant for its severe morbidity is hyperammonemic encephalopathy. We present a case of woman with hyperammonemic encephalopathy following the initiation of VPA therapy; she had a favourable outcome with discontinuation of the drug and prompt treatment with lactulose and L-carnitine.

Iatrogenic encephalopathies are not so rare in psychiatry: A retrospective study about 5217 EEG examinations

OBJECTIVES

Encephalopathy is a severe pathological process induced by multiple factors, which is typically associated with electroencephalogram (EEG) abnormalities. Early diagnosis, management, and treatment improve the patient's prognosis. Psychotropic treatments are a risk for drug-induced encephalopathies. In this study, the prevalence of encephalopathies in a psychiatric hospital has been studied for 5 years (2012 to 2016) using 5217 EEG records.

METHODS

EEGs were performed i) systematically on patient admission, ii) in response to inexplicable modifications of consciousness or behavior, or when metabolic anomalies occurred, and iii) to perform therapeutic monitoring in outpatient consultations. When encephalopathy was suspected, the clinical data (age, sex and concomitant treatment) and biological data (plasma levels of medications) were collected.

RESULTS

Encephalopathy was suspected in 189 patients. Following EEG examination, and monitoring of clinical course, encephalopathy was subsequently determined to be highly probable for 52 patients, (giving a prevalence of 1% per year), and low suspicion of encephalopathy in the other 137 patients. The suspicion of encephalopathy was made on both clinical (n=28) and non-clinical (n=24) signs. Involved drugs were mainly valproic acid (n=14), lithium (n=11) and clozapine (n=11) in the highly probable encephalopathy group.

CONCLUSIONS

Our study demonstrates the importance of EEG in the diagnosis and monitoring of encephalopathies in a psychiatric hospital. Clinical symptoms of encephalopathies are polymorphic and sometimes atypical. This diagnosis is underestimated in a context where behavior or consciousness disorders are generally not attributed to psychotropic drugs used in psychiatry.

Valproic Acid-Associated Hyperammonemia: A Systematic Review

BACKGROUND

Hyperammonemia is an adverse effect that poses clinical uncertainty around valproic acid (VPA) use. The prevalence of symptomatic and asymptomatic hyperammonemia and its relationship to VPA concentration is not well established. There is also no clear guidance regarding its management. This results in variability in the monitoring and treatment of VPA-induced hyperammonemia. To inform clinical practice, this systematic review aims to summarize evidence available around VPA-associated hyperammonemia and its prevalence, clinical outcomes, and management.

METHODS

An electronic search was performed through Ovid MEDLINE, Ovid Embase, Web of Science, and PsycINFO using search terms that identified hyperammonemia in patients receiving VPA. Two reviewers independently performed primary title and abstract screening with a third reviewer resolving conflicting screening results. This process was repeated during the full-text review process.

RESULTS

A total of 240 articles were included. Prevalence of asymptomatic hyperammonemia (5%-73%) was higher than symptomatic hyperammonemia (0.7%-22.2%) and occurred within the therapeutic range of VPA serum concentration. Various risk factors were identified, including concomitant medications, liver injury, and defects in carnitine metabolism. With VPA discontinued, most symptomatic patients returned to baseline mental status with normalized ammonia level. There was insufficient data to support routine monitoring of ammonia level for VPA-associated hyperammonemia.

CONCLUSIONS

Valproic acid-associated hyperammonemia is a common adverse effect that may occur within therapeutic range of VPA. Further studies are required to determine the benefit of routine ammonia level monitoring and to guide the management of VPA-associated hyperammonemia.

A comprehensive review on pharmacological applications and drug-induced toxicity of valproic acid

Valproic acid, a branching short chain fatty acid, is a popular drug to treat epilepsy and acts as a mood-stabilizing drug. The obstruction of ion channels and Gamma Amino Butyrate transamino butyrate GABA has been linked to antiepileptic effects. Valproic acid has been characterized as a Histone deacetylase inhibitor, functioning directly transcription of gene levels by blocking the deacetylation of histones and increasing the accessibility of transcription sites. Study has been extensively focused on pharmaceutical activity of valproic acid through various pharmacodynamics activity from absorption, distribution and excretion particularly in patients who are resistant to or intolerant of lithium or carbamazepine, as well as those with mixed mania or rapid cycling.

Undifferentiated non-hepatic hyperammonemia in the ICU: Diagnosis and management

Hyperammonemia occurs frequently in the critically ill but is largely confined to patients with hepatic dysfunction or failure. Non-hepatic hyperammonemia (NHHA) is far less common but can be a harbinger of life-threatening diagnoses that warrant timely identification and, sometimes, empiric therapy to prevent seizures, status epilepticus, cerebral edema, coma and death; in children, permanent cognitive impairment can result. Subsets of patients are at particular risk for developing NHHA, including the organ transplant recipient. Unique etiologies include rare infections, such as with Ureaplasma species, and unmasked inborn errors of metabolism, like urea cycle disorders, must be considered in the critically ill. Early recognition and empiric therapy, including directed therapies towards these rare etiologies, is crucial to prevent catastrophic demise. We review the etiologies of NHHA and highlight the first presentation of it associated with a concurrent Ureaplasma urealyticum and Mycoplasma hominis infection in a previously healthy individual with polytrauma. Based on this clinical review, a diagnostic and treatment algorithm to identify and manage NHHA is proposed.

Effect of Sodium Valproate on Weight, Body Mass Index, Uric Acid, Vitamin D3, Blood Insulin, and Serum Lipid Profile in Children

Introduction:

Due to the high prevalence of epilepsy and the use of sodium valproate as an antiepileptic drug by these patients, accurate recognition of its side effects and its effects on serum lipids profile, liver enzymes, uric acid level, and thyroid function tests, especially in cases that need long-term treatment seems essential. This study aimed to evaluate the effects of sodium valproate on weight, body mass index (BMI), vitamin D3, blood insulin, uric acid level, and serum lipids profile in children with newly diagnosed epilepsy.

Materials and Methods:

This prospective study was performed on 30 children between 3 and 8 years of age who suffered from newly diagnosed epilepsy and received sodium valproate as monotherapy. Data including demographic information (age, sex, height, weight, and waist and hip circumference of children), as well as clinical characteristics, such as liver enzymes (ALT, AST, ALK-P), serum lipids level (TG, TC, HDL-C, LDL-C), thyroid tests (TSH, T4), fasting blood sugar (FBS), uric acid level, 25 OH Vitamin D3 (Vit-D3), and blood insulin level of children before and six months after the consumption of sodium valproate, were examined.

Results:

The mean weight of children before and six months after the start of sodium valproate treatment was 18.54±2.99 and 21.13±3.93 (kg), respectively. This difference was statistically significant (P=0.005). Also, the mean weight Z-score of children before and after taking sodium valproate was -2.497 and -2.293, respectively, which was statistically significant too. In addition to weight gain, there was also a significant increase in the abdominal and hip circumference of children after taking valproate, whereas the increase in mean BMI before and after valproate administration was not statistically significant (P=0.114). However, mean weight gain, as well as the increase in the waist and hip circumference, had no relationship with gender (P> 0.05). Also, sodium valproate significantly increased the ALT level (P=0.046). Moreover, sodium valproate did not affect other liver function markers (AST), thyroid hormones (TSH, T4), fasting blood sugar (FBS), uric acid level, 25 OH Vit-D3, and the children's blood insulin levels (P> 0.05).

Conclusion:

According to the findings of this study, it can be concluded that sodium valproate is a good drug for children between 3 and 8 years of age, but it should be noted that taking this drug increases the chance of obesity in children. The main side effect of this drug is weight gain. Due to the significant increase in ALT enzyme, as observed in this study, it is recommended to check liver enzymes before, one, and six months after starting treatment as it can prevent the irreversible permanent side effects of this drug.

Impact of non-hepatic hyperammonemia on mortality in intensive care unit patients: a retrospective cohort study

BACKGROUND/AIMS

The effect of hyperammonemia on the mortality in patients with liver cirrhosis is well documented. However, little is known about the impact of hyperammonemia on mortality among intensive care unit patients without hepatic disease. We aimed to investigate factors associated with non-hepatic hyperammonemia among intensive care unit patients and to evaluate the factors related to the 7- and 90-day mortality.

METHODS

Between February 2016 and February 2020, 948 patients without hepatic disease who had 972 episodes of admission to the intensive care unit were retrospectively enrolled and classified as hyperammonemia grades 0 (≤ 80 µg/dL; 585 [60.2%]), 1 (≤ 160 µg/dL; 291 [29.9%]), 2 (≤ 240 µg/dL; 55 [5.7%]), and 3 (> 240 µg/dL; 41 [4.2%]). Factors associated with hyperammonemia and the 7- and 90-day mortality were evaluated by multivariate logistic regression analysis and Cox regression analysis, respectively. Kaplan-Meier survival curves for the 7- and 90-day mortality were constructed.

RESULTS

The independent risk factors for hyperammonemia were male sex (odds ratio, 1.517), age (0.984/year), acute brain failure (2.467), acute kidney injury (1.437), prothrombin time-international normalized ratio (2.272/unit), and albumin (0.694/g/dL). The 90-day mortality rate in the entire cohort was 24.3% and gradually increased with increasing hyperammonemia grade at admission (17.9%, 28.2%, 43.6%, and 61.0% in patients with grades 0, 1, 2, and 3, respectively). Additionally, non-hepatic hyperammonemia was an independent predictor of the 90- day mortality in intensive care unit patients.

CONCLUSION

Non-hepatic hyperammonemia is common (39.8%) and associated with the 90-day mortality among intensive care unit patients.

Valproate-Induced Hyperammonemic Encephalopathy Following Accidental Ingestion in a Toddler

Clinical manifestations of valproic acid (VPA) toxicity can range from just mild confusion and drowsiness to serious encephalopathy, leading to depressed sensorium and even coma and death. The exact cause(s) of how VPA influences the integrity of brain function remains unknown. Nevertheless, several mechanisms have been postulated including a surge in the blood ammonia concentration. Valproic acid-induced hyperammonemic encephalopathy is a rare yet serious sequalae and that can lead to grave outcomes. We report a case of hyperammonemic encephalopathy with preserved liver function following a moderate VPA intoxication in a toddler, who was successfully managed conservatively. Additionally, we briefly discuss mechanistic basis of VPA toxicity and highlight some of the available potential therapies.

Toxicity of psychotropic drugs in patients with COVID-19: A systematic review

OBJECTIVE

Due to the global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), guidance for the use of psychotropic drugs in this context is necessary. We aimed to review clinical evidence regarding the potential toxicity of psychiatric medications in the context of SARS-CoV-2 infection.

METHODS

A systematic search for all types of empirical studies and reviews in a broad set of electronic databases and trial registries was conducted up to the 15th of August 2020.

RESULTS

We identified 3 case series and 4 single-case reports on the occurrence of toxicity induced by various psychotropic drugs (lithium, n = 2; clozapine, n = 5; risperidone n = 2; haloperidol n = 1; duloxetine, n = 1). In addition, we provide a new case report on the possible precipitation of valproic acid-induced hyperammonemic encephalopathy. In most cases, SARS-CoV-2 infection may have precipitated drug toxicity/side effects. The management of toxicity did not diverge from the usually applied principles in the absence of infection.

CONCLUSIONS

Due to the limited available evidence and the recent genomic diversity and evolution of the SARS-CoV-2, it is currently not possible to derive evidence-based recommendations for the use of psychotropic drugs in the context of SARS-CoV-2 infection. Nevertheless, we provide some guidance based on the reviewed literature. At the current state of knowledge, there is no contraindication for any psychotropic drug. Caution is warranted regarding the dosing and, in particular, the monitoring of clozapine, lithium and valproate.

Use of carglumic acid in valproate-induced hyperammonemia: 25 pediatric cases

Hyperammonemic encephalopathy is a rare but potentially dangerous complication of the antiepileptic drug (AED) sodium valproate (VPA). We report a retrospective study of 25 pediatric patients, (15 females [60%]; age: 7.6 ± 4.9 years), with different underlying disorders, who suffered from hyperammonemia due to VPA and who were treated with carglumic acid (CA). The duration of treatment with VPA was 15 ± 1 month, with a dose of 40 ± 16.6 mg/kg/d. VPA blood levels were 75.5 ± 60 mg/L with seven patients being overdosed (>100 mg/L). Twenty-three patients received concomitant treatment with other AEDs. The initial dose of CA was 100 mg/kg. Subsequently, CA doses of 25 mg/kg were given to 22 patients every 6 hours (average treatment length 2.17 ± 1.1 days) until ammonemia was normalized. In nine patients, CA was used in combination with other drugs to treat hyperammonemia. In all cases, blood ammonia levels were brought under control and symptoms of hyperammonemia resolved. Two hours after CA administration, the average reduction in ammonium levels was 53 ± 29 and 88.6 ± 47.5 μmol/L at 24 hours, resulting in a statistically significant decrease when compared to pretreatment levels. There were no statistically significant differences between sexes, in the presence or not of cognitive impairment or previous carnitine treatment. There were no statistically significant differences when comparing treatment with CA plus ammonia scavengers vs CA alone. In 17 patients (68%) VPA was discontinued and 62% of the patients who maintained treatment had recurrent episodes of hyperammonemia.

Recommandations Formalisées d’Experts SRLF/SFMU : Prise en charge des états de mal épileptiques en préhospitalier, en structure d’urgence et en réanimation dans les 48 premières heures (A l’exclusion du nouveau-né et du nourrisson)

La Société de réanimation de langue française et la Société française de médecine d’urgence ont décidé d’élaborer de nouvelles recommandations sur la prise en charge de l’état mal épileptique (EME) avec l’ambition de répondre le plus possible aux nombreuses questions pratiques que soulèvent les EME : diagnostic, enquête étiologique, traitement non spécifique et spécifique. Vingt-cinq experts ont analysé la littérature scientifique et formulé des recommandations selon la méthodologie GRADE. Les experts se sont accordés sur 96 recommandations. Les recommandations avec le niveau de preuve le plus fort ne concernent que l’EME tonico-clonique généralisé (EMTCG) : l’usage des benzodiazépines en première ligne (clonazépam en intraveineux direct ou midazolam en intramusculaire) est recommandé, répété 5 min après la première injection (à l’exception du midazolam) en cas de persistance clinique. En cas de persistance 5 min après cette seconde injection, il est proposé d’administrer la seconde ligne thérapeutique : valproate de sodium, (fos-)phénytoïne, phénobarbital ou lévétiracétam. La persistance avérée de convulsions 30 min après le début de l’administration du traitement de deuxième ligne signe l’EMETCG réfractaire. Il est alors proposé de recourir à un coma thérapeutique au moyen d’un agent anesthésique intraveineux de type midazolam ou propofol. Des recommandations spécifiques à l’enfant et aux autres EME sont aussi énoncées.

Effect of antiepileptic drugs on plasma fibrinogen level

Background: Childhood  epilepsy  is  one  of  the  most  common  neurological  disorders  in pediatrics . The  prevalence  of  active  epilepsy is 5–8 per 1000 population  in developed countries  and  10 per 1000  population in  developing nations . There is a significant relationship between epilepsy and cognitive deficits. Aim of study: prospective study to evaluate the effect of the most commonly used anti-epileptics drugs on plasma fibrinogen level. Patient and methods 100 newly diagnosed patients (2months to 15 years old) selected from Outpatient Clinic of Neurology attending Mansoura University Children’s Hospital for plasma fibrinogen level evaluation by taking basal sample and second sample after six months after the basal one. Results: This study showed that, significant positive correlation between plasma fibrinogen level and the use of antiepileptic drugs. Conclusion: epileptic patient should be closely monitored during Antiepileptic drugs treatment and prior to surgical procedures as they can affect plasma fibrinogen level and coagulation profile.

Sodium valproate induced acute pancreatitis in a bipolar disorder patient: a case report

Background

Sodium valproate is one of the most widely used antiepileptics and mood stabilizers. However, this drug may induce acute pancreatitis. Few cases have been reported so far, mainly on the pediatric patients who underwent antiepileptic treatment. Hereby, we present a case of bipolar disorder with sodium valproate-induced acute pancreatitis.

Case presentation

The patient is a 54-year-old Chinese male. He was diagnosed with bipolar disorder for more than 39 years. Since the first onset of the disease, he had several relapses. The patient had had sodium valproate to stabilize mood swings for a year before the occurrence of acute pancreatitis. But he did vomit once during the inpatient care period. Then he was referred to another hospital following a notably high level of amylase. The results of computed tomography demonstrated an increased pancreatic volume and swollen peripancreatic fat tissue. As a result, the patient was diagnosed with acute pancreatitis. Unlike other cases reported in literatures, the high amylase level did not revert to normal after the withdrawal of medications. The patient was discharged from hospital with a high level of amylase, and was placed under follow-up observations.

Conclusion

Acute pancreatitis is considered as one of the idiosyncratic adverse reactions to antiepileptic drugs. Previous reports were mainly on the pediatric patients with increased propensity to idiosyncratic drug effects, or the adult chronic renal failure patients with sodium valproate-induced pancreatitis due to the retention of intermediate metabolites in their bodies. In this study, even though our patient exhibited no high risk of developing pancreatitis, he was treated for drug-induced acute pancreatitis in three hospitals. As rare as drug-induced acute pancreatitis can be, it should not be overlooked, Moreover, the mechanism of how sodium valproate induces acute pancreatitis remains unknown. Therefore, physicians need to consider the medical history of patients before prescribing this medication.

Reversible Valproate-Induced Subacute Encephalopathy Associated With a MT-ATP8 Variant in the Mitochondrial Genome

Introduction: There are several reported cases of patients developing motor and cognitive neurological impairment under treatment with valproic acid (VPA). We describe a woman who developed a subacute encephalopathy after VPA intake, harboring a mitochondrial DNA variant, previously described as causing VPA sensitivity in one pediatric patient. Material and Methods: A 65-year old woman developed a progressive, severe neurological deterioration after a 3 month treatment with valproate sodium, 800 mg daily. Magnetic resonance spectroscopy (MRS), muscle histochemical analysis and assay of mitochondrial enzymatic activities, and mitochondrial DNA sequencing were performed. Results: Neurological examination showed drowsiness, vertical gaze palsy, inability to either stand or walk, diffuse weakness, increased tendon reflexes. Blood lactate was increased, EEG showed diffuse theta and delta activity, MRI subcortical atrophy and leukoencephalopathy, MRS marked reduction of the NAA spectrum, with a small signal compatible with presence of lactate. Muscle biopsy evidenced presence of ragged red fibers (20%) and reduced COX reactivity. Assay of the muscle enzymatic activities showed multiple deficiencies of the electron transport chain and reduced ATP production. The mt.8393C>T variant in the MT-ATP8 gene was found in homoplasmy. The patient considerably improved after valproate withdrawal. Conclusion: The variant we found has been reported both as a polymorphism and, in a single patient, as related to the valproate-induced encephalopathy. The present case is the first bearing this mutation in homoplasmy. In case of neurological symptoms after starting VPA therapy, once hyperammonemia and liver failure have been ruled out, mtDNA abnormalities should be considered.

How do parents perceive adverse drug events of their children's anticonvulsant medication?

BACKGROUND

The main source of knowledge on adverse drug events (ADE) are physicians' reports in controlled clinical trials. In contrast, little is known about the parents' perception of ADE of anticonvulsants their children receive.

METHODS

After approval by the local ethics committee, we performed a survey in a neuropediatric outpatient clinic of a university hospital. Based on a structured questionnaire, we interviewed parents of children with current anticonvulsant treatment regarding (i) their fears about potential ADE, (ii) experienced ADE according to parents, and (iii) implications of ADE on the child's life.

RESULTS

Parents of 150 patients took part in the interview. (i) 95 (63.3%) parents expressed fears concerning ADE, mostly liver injury/liver failure (33 [22%]). (ii) 129 (86%) parents reported experienced ADE, mostly sedation (65 [43.3%]) and abnormal behavior (54 [36%]). (iii) Parents reported substantial implications of ADE on the child's daily life for 84 (56%) children, and 63 (42%) parents expressed a negative impact on the child's development.

CONCLUSION

We recognized a great discrepancy between those ADE that were feared and those that were experienced. Parents feared life-threatening ADE and experienced less severe ADE that nevertheless have a negative impact on the child's daily life.

Antiepileptic Drugs and Liver Disease

Acute, symptomatic seizures or epilepsy may complicate the course of hepatic disease. Choosing the most appropriate antiepileptic drug in this setting represents a difficult challenge, as most medications are metabolized by the liver. This article focuses on the acute and chronic treatment of seizures in patients with advanced liver disease and reviews the hepatotoxic potential of specific antiepileptic drugs. Newer antiepileptic drugs without, or with minimal, hepatic metabolism, such as levetiracetam, lacosamide, topiramate, gabapentin, and pregabalin should be used as first-line therapy. Medications undergoing extensive hepatic metabolism, such as valproic acid, phenytoin, and felbamate should be used as drugs of last resort. In special circumstances, as in patients affected by acute intermittent porphyria, exposure to most antiepileptic drugs could precipitate attacks. In this clinical scenario, bromides, levetiracetam, gabapentin, and vigabatrin constitute safe choices. For the treatment of status epilepticus, levetiracetam and lacosamide, available in intravenous preparations, are good second-line therapies after benzodiazepines fail to control seizures. Hepatotoxicity is also a rare and unexpected side effect of some antiepileptic drugs. Drugs such as valproic acid, phenytoin, and felbamate, have a well-recognized association with liver toxicity. Other antiepileptic drugs, including phenobarbital, benzodiazepines, ethosuximide, and the newer generations of antiepileptic drugs, have only rarely been linked to hepatotoxicity. Thus physicians should be mindful of the pharmacokinetic profile and the hepatotoxic potential of the different antiepileptic drugs available to treat patients affected by liver disease.

Toxicologic Emergencies in Patients with Mental Illness: When Medications Are No Longer Your Friends

Patients with psychiatric disorders are at risk for toxicologic emergencies. Psychotropic medications have numerous effects on the neurologic, cardiac, and other organ systems and interact with other medications, potentially leading to further side effects. It is important to become familiar with accepted psychiatric practice guidelines, common toxidromes, medical sequelae associated with prescribed medications, and the specific workup and treatment of overdoses of frequently prescribed psychotropics.

Burst Suppression Pattern on Electroencephalogram Secondary to Valproic Acid-Induced Hyperammonemic Encephalopathy

BACKGROUND

Valproic acid may induce hyperammonemic encephalopathy. Various electroencephalogram (EEG) abnormalities have been documented in association with this condition, but not burst suppression, an abnormal EEG pattern that is associated with severe encephalopathy.

METHODS

Serial EEGs, clinical observations, and laboratory findings were analyzed.

PATIENT DESCRIPTION

This 13-year-old girl with autism and intractable epilepsy experienced increased seizures; her valproic acid dose was increased and other antiepileptic drugs were administered. She became lethargic, and her EEG showed a burst suppression pattern. Her ammonia concentration was increased to 101 μmol/L and her valproic acid level was increased to 269.9 mg/L. Valproic acid was discontinued and carnitine was administered. Subsequently she became more alert, her ammonia concentration decreased, and her EEG changed from a burst suppression pattern to a continuous pattern. Within three days, she was back to her baseline level of functioning.

CONCLUSIONS

Valproic acid-induced hyperammonemic encephalopathy can produce a burst suppression EEG patternin the patient's.

L-Carnitine supplementation to reverse hyperammonemia in a patient undergoing chronic valproic acid treatment: A case report

Valproic acid is a broad-spectrum anticonvulsant that has also gained attention in the psychiatric setting. With respect to safety, valproic acid may induce a seemingly rare condition, hyperammonemia, which can induce a wide variety of symptoms ranging from irritability to coma. The proposed mechanism of hyperammonemia involves depletion of carnitine and overproduction of a toxic metabolite, 4-en-valproic acid, both of which impair the urea cycle and thus ammonia elimination. Carnitine is a commonly used antidote for acute intoxication of valproic acid, but is not a therapeutic option for management of chronic adults with adverse effects related to valproic acid. We herein report a case involving a woman with epilepsy who developed hyperammonemia after a change in her anticonvulsant therapy. She reported increased seizures and gastrointestinal disturbances. Her ammonia, valproic acid, 4-en-valproic acid, and carnitine levels were monitored. Her ammonia level was elevated and her carnitine level was at the inferior limit of the population range. She was supplemented with carnitine at 1 g/day. After 1 month, her ammonia level decreased, her carnitine level increased, and her seizures were better controlled. Carnitine supplementation was useful for reversal of her hyperammonemia, allowing her to continue valproic acid for seizure control.

Hyperammonemia: What Urea-lly Need to Know: Case Report of Severe Noncirrhotic Hyperammonemic Encephalopathy and Review of the Literature

Purpose. A 66-year-old man who presented with coma was found to have isolated severe hyperammonemia and diagnosed with a late-onset urea-cycle disorder. He was treated successfully and had full recovery. Methods. We report a novel case of noncirrhotic hyperammonemia and review the literature on this topic. Selected literature for review included English-language articles concerning hyperammonemia using the search terms “hyperammonemic encephalopathy”, “non-cirrhotic encephalopathy”, “hepatic encephalopathy”, “urea-cycle disorders”, “ornithine transcarbamylase (OTC) deficiency”, and “fulminant hepatic failure”. Results. A unique case of isolated hyperammonemia diagnosed as late-onset OTC deficiency is presented. Existing evidence about hyperammonemia is organized to address pathophysiology, clinical presentation, diagnosis, and treatment. The case report is discussed in context of the reviewed literature. Conclusion. Late-onset OTC deficiency presenting with severe hyperammonemic encephalopathy and extensive imaging correlate can be fully reversible if recognized promptly and treated aggressively.

Canadian guidelines on pharmacotherapy for disruptive and aggressive behaviour in children and adolescents with attention-deficit hyperactivity disorder, oppositional defiant disorder, or conduct disorder

OBJECTIVE

To develop evidence-based guidelines on pharmacotherapy for severe disruptive and aggressive behaviour in children and adolescents with attention-deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), or conduct disorder (CD). The guidelines assume that psychosocial interventions have been pursued but did not achieve sufficient improvement.

METHOD

A multidisciplinary consensus group used the Grading of Recommendations Assessment, Development and Evaluation approach for rating evidence quality and for grading recommendations. We conducted a systematic review of medications studied in placebo-controlled trials for treating disruptive and aggressive behaviour in children and adolescents with ADHD, ODD, or CD. We followed consensus procedures to make 1 of 4 recommendations for each medication: strong, in favour (↑↑); conditional, in favour (↑?); conditional, against (↓?); and strong, against (↓↓).

RESULTS

For children and adolescents with disruptive or aggressive behaviour associated with ADHD, psychostimulants received a strong recommendation in favour of use, while atomoxetine and alpha-2 agonists received a conditional recommendation in favour of use. If these patients do poorly with ADHD medications, the medication with the most evidence is risperidone. Risperidone also has the most evidence for treating disruptive or aggressive behaviour in the absence of ADHD. However, given risperidone's major adverse effects, it received only a conditional recommendation in favour of use. We recommended against using quetiapine, haloperidol, lithium, or carbamazepine because of the poor quality of evidence and their major adverse effects.

CONCLUSION

When severe disruptive or aggressive behaviour occurs with ADHD, medications for ADHD should be used first. Other medications have major adverse effects and, with the exception of risperidone, very limited evidence to support their use.

[French guidelines on electroencephalogram]

Electroencephalography allows the functional analysis of electrical brain cortical activity and is the gold standard for analyzing electrophysiological processes involved in epilepsy but also in several other dysfunctions of the central nervous system. Morphological imaging yields complementary data, yet it cannot replace the essential functional analysis tool that is EEG. Furthermore, EEG has the great advantage of being non-invasive, easy to perform and allows control tests when follow-up is necessary, even at the patient's bedside. Faced with the advances in knowledge, techniques and indications, the Société de Neurophysiologie Clinique de Langue Française (SNCLF) and the Ligue Française Contre l'Épilepsie (LFCE) found it necessary to provide an update on EEG recommendations. This article will review the methodology applied to this work, refine the various topics detailed in the following chapters. It will go over the summary of recommendations for each of these chapters and underline proposals for writing an EEG report. Some questions could not be answered by the review of the literature; in those cases, an expert advice was given by the working and reading groups in addition to the guidelines.

Hyperammonemia associated with valproic acid concentrations

Valproic acid, a branched short-chain fatty acid, has numerous action mechanisms which turn it into a broad spectrum anticonvulsant drug and make its use possible in some other pathologies such as bipolar disorder. It is extensively metabolized in liver, representing β-oxidation in the mitochondria one of its main metabolic route (40%). Carnitine is responsible for its entry into the mitochondria as any other fatty acid. Long-term high-dose VPA therapy or acute VPA overdose induces carnitine depletion, resulting in high levels of ammonia in blood. As a high correlation between salivary valproic acid levels and plasma ultrafiltrate levels was found in humans, saliva becomes a promising monitoring fluid in order to study valproic acid pharmacokinetics and its toxic effect. Extended-release (twice daily) formulations of valproic acid or carnitine supplementation are the proposed two therapeutic strategies in order to reverse hyperammonemia.

Valproate-induced hyperammonemia in juvenile ceroid lipofuscinosis (Batten disease)

PURPOSE

Valproate-induced hyperammonemia (VHA) and hyperammonemic encephalopathy (VHE) are well-known complications of valproate (VPA) treatment. Currently recognised risk factors for VHE include a high VPA dosage, the need for polytherapy and long duration of treatment. Despite the severe nature of the epilepsy, presence of concomitant psychiatric manifestations, and frequent need for poly-pharmacy associated with juvenile ceroid lipofuscinosis (JNCL, Batten disease) neither this disorder nor other subtypes of neuronal ceroid lipofuscinosis have previously been identified as risk factors for VHA/VHE. The aim of the present publication is to describe four cases with VHE in a well-defined Danish population of JNCL.

METHOD

An examination of medical records of all 35 patients with JNCL in Denmark was conducted and revealed fourteen patients treated with VPA.

RESULTS

Four patients treated with VPA developed VHE. All patients were prescribed VPA in standard dosages, had normal plasma concentrations of VPA and received antiepileptic drug (AED) polytherapy. Symptoms occurred shortly after commencement or increase in dose of VPA, and were quickly reversible upon discontinuation of VPA. Carnitine supplement was administrated in two patients, which resulted in resolution of symptoms and normalized ammonium levels.

CONCLUSION

Patients with JNCL are in great risk of developing VHA and VHE due to a high rate of polytherapy. Furthermore, studies have shown that carnitine level can be depressed in JNCL, which may increase the risk of VHA and VHE. We recommend that increased attention should be given to these patients.

Initial anticonvulsant monotherapy in routine care of children and adolescents: levetiracetam fails more frequently than valproate and oxcarbazepine due to a lack of effectiveness

Since anticonvulsants such as valproate or oxcarbazepine have quite a disadvantageous profile of possible adverse drug events (ADEs), safer alternatives are being sought. The newer anticonvulsant levetiracetam is often considered advantageous. We performed a chart review of children and adolescents aged from 0.5 to 16.9 years, who had been started on an initial monotherapy with levetiracetam, valproate, or oxcarbazepine between 2007 and 2011, in order to analyze the therapy's failure rate during the first year. We differentiated failure of monotherapy due to a lack of effectiveness and due to ADEs. No psychometric tests were performed. Lack of effectiveness and inacceptable ADEs were assumed according to the judgment of physicians and families. Anticonvulsive monotherapy failed in 29/61 (48 %) levetiracetam patients and in 18/49 (37 %) valproate patients (for focal and generalized epilepsies; n.s.). This was caused by a lack of effectiveness in 25/61 (41 %) levetiracetam patients and in 11/49 (22 %) valproate patients (p ≤ 0.05). A modification of therapy due to ADEs was performed in 4/61 (7 %) levetiracetam patients and in 7/49 (14 %) valproate patients (n.s.). An anticonvulsive monotherapy failed in 21/42 (50 %) patients treated with levetiracetam and in 10/34 (29 %) patients treated with oxcarbazepine (for focal epilepsies; n.s.). Changes of monotherapy were caused by a lack of effectiveness in 17/42 (40 %) of levetiracetam patients and in 6/34 (18 %) of oxcarbazepine patients (p ≤ 0.05). ADEs leading to changes in therapy were reported for 4/42 (10 %) of levetiracetam and 4/34 (12 %) of oxcarbazepine patients (n.s.). An initial monotherapy of levetiracetam failed more frequently due to a lack of effectiveness than a monotherapy with valproate or oxcarbazepine. We found no significant difference in therapy failure due to ADEs.

Valproic acid-associated low fibrinogen and delayed intracranial hemorrhage: case report and mini literature review

A 41-year-old male had suffered from gradual hearing loss in his right ear for 2 years. Head computed tomography and magnetic resonance imaging scans showed a neoplasm in the cerebellopontine angle region, which was confirmed by the diagnosis of acoustic neurilemmoma by pathological findings after surgery. Following surgery, he routinely received valproic acid (VPA) to prevent seizures. However, the patient presented with hypofibrinogenemia and cerebral hemorrhage after taking VPA for 12 days. The hypofibrinogenemia recurred when VPA was re-administered. After withdrawal of VPA, his fibrinogen concentration rose to normal within several days. As far as we are aware, this is the first case of cerebral hemorrhage due to VPA to have been reported. Herein, as well as reporting on this case, a mini review of the relevant literature is also presented.

Twenty-four hour non-invasive ambulatory blood pressure and heart rate monitoring in Parkinson's disease

Non-motor symptoms are now commonly recognized in Parkinson's disease (PD) and can include dysautonomia. Impairment of cardiovascular autonomic function can occur at any stage of PD but is typically prevalent in advanced stages or related to (anti-Parkinsonian) drugs and can result in atypical blood pressure (BP) readings and related symptoms such as orthostatic hypotension (OH) and supine hypertension. OH is usually diagnosed with a head-up-tilt test (HUT) or an (active) standing test (also known as Schellong test) in the laboratory, but 24 h ambulatory blood pressure monitoring (ABPM) in a home setting may have several advantages, such as providing an overview of symptoms in daily life alongside pathophysiology as well as assessment of treatment interventions. This, however, is only possible if ABPM is administrated correctly and an autonomic protocol (including a diary) is followed which will be discussed in this review. A 24-h ABPM does not only allow the detection of OH, if it is present, but also the assessment of cardiovascular autonomic dysfunction during and after various daily stimuli, such as postprandial and alcohol dependent hypotension, as well as exercise and drug induced hypotension. Furthermore, information about the circadian rhythm of BP and heart rate (HR) can be obtained and establish whether or not a patient has a fall of BP at night (i.e., "dipper" vs. non-"dipper"). The information about nocturnal BP may also allow the investigation or detection of disorders such as sleep dysfunction, nocturnal movement disorders, and obstructive sleep apnea, which are common in PD. Additionally, a 24-h ABPM should be conducted to examine the effectiveness of OH therapy. This review will outline the methodology of 24 h ABPM in PD, summarize findings of such studies in PD, and briefly consider common daily stimuli that might affect 24 h ABPM.

Lacosamide-induced valproic acid toxicity

Valproic acid is commonly used in the treatment of both focal and generalized epilepsies and is often well tolerated. There are many reported cases of hyperammonemic encephalopathy and other well-known side effects reported during use of valproic acid either alone or in combination with other antiepileptics. This case report demonstrates valproic acid toxicity in the presence of lacosamide, which has not previously been reported. Full recovery occurred after withdrawal of both valproic acid and lacosamide.

Valproate-induced hyperammonaemia superimposed upon severe neuropsychiatric lupus: a case report and review of the literature

This paper presents a case of systemic lupus erythematosus (SLE) with neuropsychiatric features, where the outcome was influenced by the development of hyperammonaemia, probably induced by sodium valproate. A case of severe SLE occurring in a 20-year-old Maori girl is described. Her disease had been characterised by neuropsychiatric features for several years, culminating in persistent seizure activity at the time of her final presentation. Her management with anticonvulsants was complicated by the development of intractable hyperammonaemia which contributed to irreversible clinical deterioration. We have reviewed the English literature for reports of valproate-related hyperammonaemia which has often been described in the setting of seizure and mood disorders. This is the first case where it has been reported, superimposed upon severe neuropsychiatric SLE (NP-SLE). The mechanism by which valproate induces hyperammonaemia remains incompletely understood but is likely to relate to the urea cycle. Under normal metabolic conditions, acyl-CoA is transported into the mitochondria via a carnitine transport system. It is then converted to acetyl-CoA via β-oxidation and eventually to N-acetyl glutamate. This pathway can be interrupted by the introduction of sodium valproate, leading to a reduction of free coenzyme A, acetyl-CoA and carnitine, and resulting in the decreased availability of cofactors necessary for the function of the urea cycle. As this is the primary means of ammonia metabolism, serious elevation in serum ammonia levels may occur in patients on this anticonvulsant medication. In this patient with active NP-SLE, the combined autoimmune and metabolic brain insult contributed to a fatal outcome.

Spirulina (arthrospira) protects against valproic acid-induced neural tube defects in mice

Valproic acid (VPA) is a potent inducer of neural tube defects in human and mouse, its teratogenicity is associated with its potential to generation of free radicals and increase oxidative stress. Furthermore, spirulina (SP) has shown pharmacological properties against teratogenicity, which are attributed to its antioxidant potential. Accordingly, the present study was performed to investigate the influence of SP on the teratogenicity of VPA in imprinting control region mice and the possible mechanisms of action. VPA (sodium valproate) was administered intraperitoneally to mice on gestation day (GD) 8 at a dose of 600 mg/kg. SP was given orally at 125, 250, and 500 mg/kg daily from GD0 through GD18. The most common finding in fetuses with VPA exposure was exencephaly. SP decreased the incidence of this and other malformations and increased levels of superoxide dismutase, catalase, and glutathione peroxidase. In conclusion, these results illustrate the protective action of SP through its antioxidant activity against VPA-induced teratogenicity.

Topiramate increases the risk of valproic acid-induced encephalopathy

Metabolic encephalopathy is a rare but serious complication of valproic acid (VPA) therapy that usually presents with impaired consciousness or increased seizure frequency. Although it has been suggested that topiramate (TPM) increases the risk of VPA-induced encephalopathy, the additional risk in patients receiving TPM therapy has not been evaluated. We reviewed all adult patients who took VPA between January 2005 and February 2009 at the Seoul National University Hospital and identified patients with VPA-induced encephalopathy based on clinical and electroencephalography (EEG) data. Information on sex, age, serum ammonia level, serum VPA level, liver function test, and EEG was collected from patient registry and medical data. We enrolled 8,372 patients who received VPA therapy and 1,236 patients who received VPA/TPM combination therapy. We identified 11 patients with VPA-induced encephalopathy (0.13%), 7 of whom received a combination therapy of VPA and TPM. The odds ratio of VPA-induced encephalopathy with TPM over that without TPM was 10.16. There were no significant differences in sex distribution, number of antiepileptic agents, ammonia level, VPA serum level, underlying diseases, dosage of VPA, duration of VPA treatment, treatment of encephalopathy, and outcomes between the two groups. Our study showed that the prevalence of VPA-induced encephalopathy is approximately 0.1% among patients treated with VPA and that the risk of this condition, although still low, can increase by approximately 10 times in the presence of TPM therapy. Based on these results, we suggest that TPM should be carefully used in patients receiving VPA treatment.

Noncirrhotic hyperammonaemic encephalopathy

Adult hyperammonaemia is associated with severe liver disease in 90% of cases. In the remainder, noncirrhotic causes should be considered. Measurements of serum ammonia level must be part of the basic work-up in all patients presenting with encephalopathy of unknown origin, even when liver function is normal. Clinician awareness of noncirrhotic hyperammonaemic encephalopathy can contribute to early diagnosis and the initiation of sometimes life-saving treatment. This review focuses on the physiology, aetiology and underlying mechanisms of noncirrhotic hyperammonaemic encephalopathy and discusses the available treatment modalities.

Seizures after cardiac surgery

INTRODUCTION

Cardiac surgery, mainly in the form of coronary artery bypass graft surgery, is known to be associated with a risk of injury to the central and peripheral nervous systems. The most commonly encountered central nervous system injury associated with cardiac surgery continues to be stroke, with seizures occurring less commonly but with significant consequences. Seizures in the cardiac surgery recovery unit (CSRU) always cause great concern to the attending physicians and families of the patient. Therefore, it is of critical importance that the attending physician has an accurate and efficient approach to the differential diagnosis, investigations, and management of these patients, who represent a unique group requiring specific investigations and management.

METHODS

A review and discussion of experience with seizures in the CSRU.

DISCUSSION

Cardiac surgery poses a significant threat to the nervous system through various mechanisms although newer technologies and surgical techniques have led to improved outcomes in recent years. Although the incidence of seizures remains low, the causes and management are relatively unique in this setting, including a probable "toxic syndrome" related to certain antibiotics or other perioperative drugs such as tranexamic acid. A targeted approach based on recognizing focal versus generalized seizures, a careful review of history and medications, and a focused workup will lead the clinician to choosing the most effective therapy when one is required. Special concerns regarding the side effect profile of phenytoin in this setting have led to valproate and levetiracetam becoming useful alternatives, which are effective and well tolerated. The incidence of nonconvulsive seizures in the CSRU remains to be elucidated with prospective monitoring studies, as does their effect on outcome.

Adult nonhepatic hyperammonemia: a case report and differential diagnosis

This article presents a case report of nonhepatic hyperammonemia, i.e., elevated serum ammonia secondary to a nonhepatic etiology. It then discusses the importance of broadening one's differential diagnosis to include such nonhepatic causes of elevated ammonia levels, and provides a short review of rarer causes of hyperammonemia in the adult population. Treating the underlying condition is the best way to prevent recurrence of hyperammonemia. However, symptomatic treatment should not be delayed while investigating the underlying source.

Molecular and therapeutic potential and toxicity of valproic acid

Valproic acid (VPA), a branched short-chain fatty acid, is widely used as an antiepileptic drug and a mood stabilizer. Antiepileptic properties have been attributed to inhibition of Gamma Amino Butyrate (GABA) transaminobutyrate and of ion channels. VPA was recently classified among the Histone Deacetylase Inhibitors, acting directly at the level of gene transcription by inhibiting histone deacetylation and making transcription sites more accessible. VPA is a widely used drug, particularly for children suffering from epilepsy. Due to the increasing number of clinical trials involving VPA, and interesting results obtained, this molecule will be implicated in an increasing number of therapies. However side effects of VPA are substantially described in the literature whereas they are poorly discussed in articles focusing on its therapeutic use. This paper aims to give an overview of the different clinical-trials involving VPA and its side effects encountered during treatment as well as its molecular properties.

Valproic acid-induced abnormal behavior

A 12-year-old female was admitted to hospital with complaints of abnormal behavior. She was on valproic acid 200mg twice daily and clobazam 5mg at night for the past 13 weeks for her complex partial seizures with secondary generalized seizures. On day 60 of the treatment with valproic acid she developed behavioral disturbances and initiated treatment with tablet chlorpromazine, olanzapine and risperidone. During the present hospitalization, as there was no improvement in abnormal behavior, antipsychotics were discontinued and she was on observation for five days. On day 6, valproic acid was replaced with carbamazepine. Patient started recovering gradually from the abnormal behavior three days after the withdrawal of valproic acid and completely recovered after three months. Causality of valproic acid-induced abnormal behavior was 'possible'. Behavioral disturbances associated with valproic acid are rare and is reversible upon discontinuation of the drug. There is a need for vigilance on abnormal behavioral effects in patients receiving valproic acid.

Somatosensory evoked potentials in epileptic children treated with carbamazepine or valproate in monotherapy - a preliminary study

PURPOSE

Data from the literature suggest that long-term therapy with various antiepileptic drugs can be responsible for the functional disturbances within the nervous system e.g. peripheral neuropathy and encephalopathy. Useful and non-invasive instruments for evaluation of even subclinical nerve conduction abnormalities in somatosensory tracts are somatosensory evoked potentials (SEPs). The aim of this study was to assess the potentially drug-induced abnormalities in the SEP parameters in epileptic children, treated chronically in monotherapy with one of the two most often used antiepileptic drugs: valproate (VPA) or carbamazepine (CBZ).

MATERIALS AND METHODS

SEP from left median nerve stimulation were recorded in twenty children with idiopathic/cryptogenic epilepsy treated in monotherapy with CBZ (9 patients) or VPA (11 patients). The mean age of the patients was 13.4 ± 2.9 years (range 7-17 years). The plasma concentrations of the drugs were consistently within therapeutic range. The mean duration of treatment was eight months. The control group consisted of twenty-four age-matched children with tension type headache. The latencies of the components: N9, N13, N20, P25 and the peripheral conduction time (PCT) and central conduction time (CCT) were analyzed.

RESULTS

No significant differences in all analyzed SEP parameters between the epileptic and control children were found.

CONCLUSIONS

Our results indicate that during the first 8 months from the beginning of antiepileptic treatment in children, monotherapy with VPA or CBZ does not induce nerve conduction disturbances within both the peripheral- and the central part of the somatosensory tracts, detected in SEP examination.

Stupor and fast activity on electroencephalography in a child treated with valproate

The case of a 4-year-old girl with valproate-induced stupor and electroencephalographic pattern of increased fast activity is reported. Stupor and fast activity have been related to the effects on gamma-aminobutyric acid type A (GABA(A)) receptors mediated by endozepines or by exogenous drugs such as benzodiazepines or barbiturates. The action of valproate in GABA metabolism and in GABA neuronal networks could produce a similar result through a hyperrecruitment of GABA-mediated postsynaptic transmission.

[Differential diagnosis of status epilepticus]

The diagnosis of status epilepticus can be retained, wrongly, in several circumstances. Nonepileptic pseudoseizures from a psychiatric origin and some movement disorders can mimic convulsive status epilepticus. Encephalopathy of various causes (post-anoxic, metabolic, toxic, Creutzfeldt-Jakob disease) can be wrongly taken for non-convulsive status epilepticus, mainly due to inadequate interpretation of the electroencephalogram (EEG). In these encephalopathies, the existence of (non-epileptic) myoclonus and the abolition of the EEG abnormalities with the use of a benzodiazepine (without correction of the clinical symptoms) are additional confounding factors, leading to false diagnosis. Nevertheless, in general, the diagnosis of status epilepticus can be confirmed or rejected base on a combined analysis of the clinical data and the EEG.

Valproate-associated reversible encephalopathy in a 3-year-old girl with Pallister-Killian syndrome

Valproic acid (VPA) is considered to be a drug of first choice for the therapy of generalized and focal epilepsies, including special epileptic syndromes. The drug is usually well tolerated, rare serious complications may occur in some patients, including hemorrhagic pancreatitis, coagulapathies, bone marrow suppression, VPA-induced hepatotoxicity and encephalopathy. We report a case of VPA-associated encephalopathy without hyperammonemia in a 3-year-old girl with Pallister-Killian-Syndrom, combined with a mild hepatopathy and thrombopathy. After withdrawal of VPA, the clinical symptoms and the electroencephalography-alterations vanished rapidly.