Effects of chronic administration of valproic acid to epileptic patients on coagulation tests and primary hemostasis

Safety of Concomitant Cortical and Thalamic Stereoencephalography Explorations in Patients With Drug-Resistant Epilepsies

BACKGROUND AND OBJECTIVES

Intracranial electrophysiology of thalamic nuclei has demonstrated involvement of thalamic areas in the propagation of seizures in focal drug-resistant epilepsy. Recent studies have argued that thalamus stereoencephalography (sEEG) may aid in understanding the epileptogenic zone and treatment options. However, the study of thalamic sEEG-associated hemorrhage incidence has not been investigated in a cohort study design. In this article, we present the largest retrospective cohort study of sEEG patients and compare hemorrhage rates between those with and without thalamic sEEG monitoring.

METHODS

Retrospective chart review of clinical and epilepsy history, electrode implantation, rationale, and outcomes was performed for 76 patients (age 20-69 years) with drug-resistant epilepsy who underwent sEEG monitoring at our institution (2019-2022). A subset of 38% of patients (n = 30) underwent thalamic monitoring of the anterior thalamic nucleus (n = 14), pulvinar nucleus (n = 25), or both (n = 10). Planned perisylvian orthogonal sEEG trajectories were extended to 2- to 3-cm intraparenchymally access thalamic area(s).The decision to incorporate thalamic monitoring was made by the multidisciplinary epilepsy team. Statistical comparison of hemorrhage rate, type, and severity between patients with and without thalamic sEEG monitoring was made.

RESULTS

Our approach for thalamic monitoring was not associated with local intraparenchymal hemorrhage of thalamic areas or found along extended cortical trajectories, and symptomatic hemorrhage rates were greater for patients with thalamic coverage (10% vs 0%, P = .056), although this was not found to be significant. Importantly, patients with perisylvian electrode trajectories, with or without thalamic coverage, did not experience a higher incidence of hemorrhage (P = .34).

CONCLUSION

sEEG of the thalamus is a safe and valuable tool that can be used to interrogate the efficacy of thalamic neuromodulation for drug-resistant epilepsy. While patients with thalamic sEEG did have higher incidence of hemorrhage at any monitoring site, this finding was apparently not related to the method of perisylvian implantation and did not involve any trajectories targeting the thalamus.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Assessment of need for hemostatic evaluation in patients taking valproic acid: A retrospective cross-sectional study

INTRODUCTION

Valproic acid (VPA) is a frequently prescribed anti-epileptic drug. Since its introduction side effects on hemostasis are reported. However, studies show conflicting results, and the clinical relevance is questioned. We aimed to determine the coagulopathies induced by VPA in patients who undergo high-risk surgery. The study results warrant attention to this issue, which might contribute to reducing bleeding complications in future patients.

METHODS

Between January 2012 and August 2020, 73 consecutive patients using VPA were retrospectively included. Extensive laboratory hemostatic assessment (including platelet function tests) was performed before elective high-risk surgery. Patient characteristics, details of VPA treatment, and laboratory results were extracted from medical records.

RESULTS

46.6% of the patients using VPA (n = 73) showed coagulopathy. Mainly, platelet function disorder was found (36.4%). Thrombocytopenia was seen in 9.6% of the patients. Data suggested that the incidence of coagulopathies was almost twice as high in children as compared to adults and hypofibrinogenemia was only demonstrated in children. No association was found between the incidence of coagulopathies and VPA dosage (mg/kg/day).

CONCLUSION

A considerable number of patients using VPA were diagnosed with coagulopathy, especially platelet function disorder. Further prospective studies are needed to confirm the need for comprehensive laboratory testing before elective high-risk surgery in these patients.

Switching Between LC-ESI-MS/MS and EMIT Methods for Routine TDM of Valproic Acid in Pediatric Patients With Epilepsy: What Clinicians and Researchers Need to Know

Background: Valproic acid (VPA) is a widely used antiseizure medication and its dosing needs to be tailored individually through therapeutic drug monitoring (TDM) to avoid or prevent toxicity. Currently, immune-enzymatic assays such as Enzyme Multiplied Immunoassay Technique (EMIT), and Liquid Chromatography (LC)-based techniques, particularly coupled to Electrospray Ionization Tandem Mass Spectrometry (LC-ESI-MS/MS), resulting a potential lack of concordance between laboratories. Methods: In this study, plasma VPA concentrations were determined for 711 pediatric patients with epilepsy by a routine EMIT assay and by a validated in-house LC-ESI-MS/MS method on the same group of samples, aimed to address the aforementioned concern. Consistency between two assays was evaluated using linear regression and Bland-Altman analysis. Results: The calibration curve was linear in the range of 5.00-300 μg/ml for LC-ESI-MS/MS method and 1.00-150 μg/ml for EMIT assay, respectively. The two methods were proven to be accurate with quality control samples. As a result, a significant correlation between two methods was obtained with a regression equation described as [ EMIT ] = 1.214 × [ LC - ESI - MS / MS ] + 3.054 (r ² = 0.9281). Bland-Altman plot showed a mean bias of 14.5 μg/ml (95% confidence interval (CI) (-0.2, 29.2) and a mean increase of 27.8% (95% CI (3.3, 52.4) measured by EMIT assay more than that measured by LC-ESI-MS/MS method. Conclusion: In conclusion, two methods were closely correlated, but EMIT assay overestimate VPA levels in human plasma compared with LC-ESI-MS/MS method. Due to the observed significant discordance between the tested methods, switching from immunoassays to LC-based techniques for TDM of VPA deserves close attention and therapeutic range of 35.0-75.0 μg/ml may be feasible. However, further studies are needed to evaluate the eligibility of this alternative range in the clinical practice. Clinicians should be informed when switching the VPA quantitation methods during the clinical practice.

Predicting the occurrence of thrombocytopenia from free valproate levels: A prospective study

PURPOSE

The likelihood of valproate (VPA) induced thrombocytopenia increases with higher VPA levels. In critically ill patients, the biological active free VPA level cannot be predicted from the total serum level. In this study, we evaluated the relationship between trough free VPA serum levels and concomitant platelet counts and assessed risk factors for the development of thrombocytopenia with the aim of generating a formula specifying the probabilities of developing thrombocytopenia based on trough free serum VPA levels.

METHODS

Trough free VPA levels and concomitant platelet counts were collected from a large cohort of patients who participated in a prospective VPA monotherapy trial. Significant variables associated with thrombocytopenia in a univariate analysis were evaluated in a multivariate model. A receiver operator curve was performed to compute the trough free VPA levels with the greatest discriminating power in predicting thrombocytopenia.

RESULTS

844 trough free VPA levels and concomitant platelet counts obtained from 264 patients were analyzed. In a multivariate analysis, trough free VPA levels, gender, and baseline platelet counts were significantly associated with thrombocytopenia. Using stepwise regression and multivariate logistic regression analyses, we generated gender-specific formulas for predicting platelet counts and probabilities of developing thrombocytopenia. The trough free VPA with the greatest discriminating power to predict platelet values ≤ 100,000/μL was 16.65 µg/mL.

CONCLUSIONS

The generated model was based on trough free VPA levels and achieved high sensitivity and specificity. Our results are therefore generalizable and can be applied to estimate the probability of developing thrombocytopenia in critically ill patients.

Blood Loss and Related Laboratory Changes after Single-Event Multilevel Surgery and Hip Reconstructive Surgery in Patients with Cerebral Palsy

Backgroud

Single-event multilevel surgery (SEMLS) and hip reconstructive surgery (HRS) often cause intraoperative bleeding, consequently increasing the probability of transfusion and postoperative laboratory changes. Therefore, it is important to assess risk factors to predict the amount of blood loss. This study aimed to evaluate blood loss, its influencing factors, and the related laboratory changes during SEMLS and HRS in patients with cerebral palsy (CP).

Methods

We retrospectively examined consecutive CP patients who underwent SEMLS and HRS. Surrogate markers of blood loss, including preoperative and postoperative hemoglobin (Hb), hematocrit, and changes in Hb concentration, were assessed. Albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatine levels were also analyzed for related laboratory changes. Risk factors were analyzed using multiple regression and logistic regression models.

Results

The overall cohort comprised 1,188 patients. Of them, 1,007 and 181 underwent SEMLS and HRS, respectively. Furthermore, 72 of 181 patients underwent a concomitant Dega osteotomy. The regression model showed that low preoperative Hb concentration (p < 0.001), high albumin level (p = 0.007), low body mass index (BMI) (p = 0.002), and bilateral HRS (p < 0.001) were significant risk factors of postoperative anemia. Valproate medication was associated with Hb drop, and the risk factors for Hb level < 8 g/dL on postoperative day 2 were bilateral HRS and Dega osteotomy in the HRS subgroup. In total, 21.6% had elevated AST levels on postoperative day 2, and bilateral HRS (p < 0.001), Gross Motor Function Classification System (GMFCS) level V (p = 0.041), Dega osteotomy (p < 0.001), and high preoperative AST level (p < 0.001) increased the risk of AST elevation.

Conclusions

We have summarized the estimated blood loss and related laboratory changes after SEMLS and HRS in patients with CP and identified the risk factors. Clinical guidelines should be accordingly developed to include assessment of these risk factors and their impact in the outcomes of CP patients undergoing SEMLS and HRS.

Effects of the ketogenic diet on platelet counts and global coagulation tests in childhood epilepsy

PURPOSE

Several antiseizure drugs (ASD), especially Valproic acid (VPA), influence platelet counts and coagulation parameters. The ketogenic diet (KD), established in drug-resistant epilepsy, is combined with ASDs. Bruising and prolonged bleeding times during KD have been described, but whether hemostatic changes result from the KD or from concomitant ASDs, remains unclear. Aim of the present study was to evaluate bleeding, platelet counts and global coagulation tests prior to and during KD in childhood epilepsy.

METHOD

Consecutive children treated with KD were systematically observed for bleeding. Serial measurements of platelet counts and global coagulation tests (APTT, PT and fibrinogen) were obtained at baseline and during KD (at 1, 3, 6 and 12 months). Children with KD monotherapy, concomitant VPA, or other ASDs were compared.

RESULTS

Among 162 children receiving KD, we observed neither bleeding in daily life nor perioperative bleeding in those undergoing surgery (n = 25). Most children had normal platelet counts and coagulation parameters. Only a few had transient mild thrombocytopenia and mildly prolonged APTT values, not indicative of a bleeding risk. Even KD combined with VPA did not cause relevant coagulopathy. Unexpectedly, we found mild thrombocytosis in 24 % of patients prior to KD, which was most pronounced in yet untreated epilepsy. Thrombocytosis steadily resolved during KD.

CONCLUSIONS

During KD treatment of childhood epilepsy, we observed neither bleeding symptoms nor laboratory results indicating a bleeding risk. Unexpectedly, mild thrombocytosis was present in 24 % at baseline, normalising during KD. Thrombocytosis may reflect the underlying inflammatory process of untreated epilepsy and requires further study.

Practice of stereoelectroencephalography (sEEG) in drug-resistant epilepsy: Retrospective series with surgery and thermocoagulation outcomes

OBJECTIVE

The aim of this study was to determine the success rate of sEEG in locating the epileptogenic zone (EZ) in patients with pharmaco-resistant epilepsy. Secondary objectives were to analyze sEEG-related morbidity and outcomes for post-sEEG thermocoagulation and cortical resection.

METHODS

Data were collected on 49 sEEGs from 46 consecutive patients between 2010 and 2018. Following sEEG, either resective or palliative surgery with vagus nerve stimulation was performed. In 8 patients, EZ thermocoagulation was performed before EEG leads were withdrawn. Outcomes were collected based on the Engel and ILAE outcome scales.

RESULTS

sEEG was contributive in 45 of 49 recordings, with a success rate of 92% in locating the EZ. Minor complications, such as transient neurologic deficit and electrode implantation failures, occurred in 6%. One major complication occurred, with death due to atypical late hematoma. Thermocoagulation was performed in 8 patients and stopped or significantly reduced seizure frequency in 7 (88%). Outcome of surgical resection (n=33) was good, with 20 (61%) seizure-free patients and 32 (97%) with definite improvement.

CONCLUSIONS

Our findings suggest that sEEG is an effective technique for EZ location in patients with drug-resistant epilepsy. sEEG was contributive in up to 92% of patients, allowing thermocoagulation and/or surgical resection that resulted in seizure-freedom in two-thirds and seizure-reduction in one-third of cases. This study highlights the need for strict selection of implantation candidates, with strong initial hypothesis as to EZ location.

Determination of unbound valproic acid in plasma using centrifugal ultrafiltration and gas chromatography:Application in TDM

AIM

In order to monitor the free concentration of VPA in plasma, a simple and rapid method needs to be developed.

METHODS

The free fraction of VPA in plasma was obtained by centrifugal ultrafiltration (CF-UF) devices. Cyclohexanecarboxylic acid was used as internal standard. Valproate in plasma was converted to VPA by sulphuric acid acidification, and dichloromethane was used as solvent for extraction. Nitrogen was the carrier gas, the samples were separated by capillary column, and the flame ionization detector was used to detect VPA fragment ions for quantitative analysis.

RESULTS

The assay had good specificity and stability. The linear range of the assay was 0.56-28.11 mg/L. The intra-day and inter-day precision (RSDs) of the assay were all within 15%, and the accuracy (RE) was 2.58%. The recoveries of VPA with three different concentrations were 102.03 ± 1.05, 101.45 ± 2.08 and 102.58 ± 3.38. The results of therapeutic drug monitoring (TDM) in pediatric inpatient group and outpatient group showed significant differences between the two groups (P < 0.001).

CONCLUSION

This assay has low cost and good analytical performance, so it can be developed into a routine TDM method of unbound VPA. We recommend the monitoring of unbound VPA concentration in pediatric inpatients during clinical use of VPA.

Valproic Acid-Induced Coagulopathy

BACKGROUND

Valproic acid is one of the most commonly used antiseizure medications. Multiple hematologic abnormalities have been reported with the use of valproic acid, which may be particularly relevant in the perioperative surgical setting. The incidence of these abnormalities and prevalence of periprocedural hemorrhage vary significantly in the published literature. In this article we analyze the prevalence and possible etiology of coagulopathy and hemorrhage in patients receiving valproic acid.

METHODS

A literature search was completed using "VPA," "coagulopathy," and "surgery." The available published data from case reports to large case series were reviewed.

RESULTS

Thrombocytopenia was noted to be the most common laboratory abnormality associated with valproic acid. An association between valproic acid and acquired von Willebrand disease has also been suggested. There are case reports describing bleeding in the setting of hypofibrinogenemia and factor XIII deficiency. Perioperative hemorrhage was reported in pediatric studies of orthopedic procedures, but not in adult cohorts undergoing neurosurgical interventions.

CONCLUSIONS

VPA use can cause thrombocytopenia and other coagulation abnormalities. Rigorous, prospective trials are needed to better assess the association between valproic acid and clinically significant coagulopathy. Until such data are available, physicians need to be aware of the potential risk of bleeding in patients receiving valproic acid. A hemostatic evaluation should be considered in symptomatic patients, and may be considered for patients taking VPA who are scheduled for surgery. If an abnormality is detected, hematologists should be involved to make recommendation on perioperative hemostatic strategy.

Perioperative management of patients with cerebral palsy undergoing scoliosis surgery: Survey of surgeon practices

PURPOSE

Progressive scoliosis significantly impacts the quality of life in patients with cerebral palsy (CP). Spinal fusion is the mainstay of treatment of progressive spinal curves. The current study aims to identify approaches used by pediatric spine surgeons to optimize care of patients with CP undergoing scoliosis surgery.

METHODS

A 33-question survey was distributed electronically to 181 POSNA/SRS members with an established interest in pediatric spinal deformity surgery. Eighty one responses were obtained (45%). Using the Delphi consensus guidelines, agreement > 75% was considered as consensus.

RESULTS

There was a consensus on 15 out of 33 questions (46%). 97% of responders identified nutrition status as a comorbidity which could be optimized. However, the timing and method of obtaining nutritional assessment varied. 92% of the surgeons stated that they used shared decision making with the family but only 22% used a formal decision aid. 83% use antifibrinolytics routinely, 81% used a surgical site infection prevention protocol, 78% obtained preoperative pulmonary consult, and 88% took steps postoperatively to prevent pulmonary complications.

CONCLUSION

There is significant variability in the current practices of perioperative management of patients with CP undergoing scoliosis surgery. This data can be used in future studies to create a standardized integrated care pathway.

The Risk of Thrombocytopenia During Valproic Acid Therapy: A Critical Summary of Available Clinical Data

Valproate is an effective anti-epileptic and mood stabilizer drug, but its prescription may be complicated by the development of thrombocytopenia. The purpose of the present manuscript is to provide a critical overview about the risk of thrombocytopenia during treatment with valproate. A search of the main database sources has been conducted to identify relevant papers about the topic. In the studies with a larger sample size (> 150 subjects), thrombocytopenia occurred in 12–18% of subjects receiving treatment with valproate. Advanced age, female gender, and high doses were found to be risk factors for the development of thrombocytopenia during treatment with valproate. Future research is needed to clarify the clinical impact of the occurrence of thrombocytopenia during valproate treatment (e.g., the risk of life-threatening events such as stroke or the development of thrombocytopenia during short- versus long-term administration, or oral versus intravenous formulations).

European Stroke Organisation guidelines for the management of post-stroke seizures and epilepsy

Background

Following stroke, acute symptomatic seizures (manifestation within seven days) and epilepsy, i.e. occurrence of at least one unprovoked seizure (manifestation after more than seven days), are reported in 3-6% and up to 12% of patients, respectively. Incidence of acute symptomatic seizures is higher in intracranial haemorrhage (10-16%) than in ischaemic stroke (2-4%). Acute symptomatic seizures and unprovoked seizure may be associated with unfavourable functional outcome and increased mortality. In view of the clinical relevance, the European Stroke Organisation has issued evidence-based guidelines on the management of post-stroke seizures and epilepsy.

Method

A writing committee of six clinicians and researchers from five European countries and Israel identified seven questions relating to prevention of (further) post-stroke seizures and epilepsy and to amelioration of functional outcome and prevention of mortality. Recommendations are based on findings in randomised controlled trials and observational studies using the grading of recommendations assessment, development and evaluation approach.

Results

In the absence of adequately powered randomised controlled trials, evidence for all recommendations is very low. Based on findings in observational studies, some weak recommendations have been made. In most instances, we suggest not to administer antiepileptic drugs. Due to high incidence of seizure recurrence after one post-stroke unprovoked seizure, secondary antiepileptic drugs prophylaxis needs to be considered.

Conclusion

Due to very low evidence, these guidelines only give some weak recommendations on prevention of occurrence and recurrence of post-stroke acute symptomatic seizures and unprovoked seizure. Adequately powered randomised controlled trials are required to assess interventions for post-stroke seizure management.

Dental care in patients with epilepsy: a survey of 82 patients and their attending dentists and neurologists in southern Germany

INTRODUCTION

The current study assessed the knowledge and attitudes of dentists and neurologists, and of their patients with epilepsy, in the catchment area of an outpatient clinic for epilepsy in southern Germany.

METHODS

One-hundred patients with epilepsy were asked to complete questionnaires about their dental treatment. Attitudes of their attending dentists and neurologists were also assessed.

RESULTS

Patients with epilepsy: The questionnaires were returned by 82% of patients. Of these, 84% regularly (once or twice a year) sought out a dentist, 79% reported their epilepsy to the dentist, 6% were refused treatment by a dentist because of their epilepsy, 10% had already experienced a seizure while at a dental office and 52% wished for more detailed information pretreatment. Dentists: Although 97% treated patients with epilepsy, 21% believed that their equipment was inappropriate for treating a patient experiencing seizures. The majority were not familiar with interactions between antibiotics/analgetics and anti-epileptic drugs. Short-term general anaesthesia was preferred for critical patients by 70% of dentists, 70% recommended dental ceramic for prosthetic reconstruction of anterior teeth and 64% would not recommend use of a removable denture. Neurologists: Sixty-two per cent were asked for advice by their patients, 71% knew about particular risks and interactions between antibiotics/analgetics and anti-epileptic drugs, 8% would stop valproic acid before extensive dental intervention and 92% recommended general anaesthesia in critical patients (uncooperative patients, patients with learning difficulties, and patients with frequent generalised tonic-clonic or complex partial seizures).

DISCUSSION

In general, patients were satisfied with their dental treatment. Regarding the clinician's role, however, dentists need to know more with respect to treating patients with seizures. Beyond that, it would be desirable for neurologists to take more time to answer their patients' questions regarding dental care.