Effects of treatment on endocrine function in patients with epilepsy

Analysis of the action mechanisms and targets of herbal anticonvulsants highlights opportunities for therapeutic engagement with refractory epilepsy

Epilepsy is a neurological disorder characterized by spontaneous and recurring seizures. It poses significant therapeutic challenges due to diverse etiology, pathobiology, and pharmacotherapy-resistant variants. The anticonvulsive effects of herbal leads with biocompatibility and toxicity considerations have attracted much interest, inspiring mechanistic analysis with the view of their use for engagement of new targets and combination with antiseizure pharmacotherapies. This article presents a comprehensive overview of the key molecular players and putative action mechanisms of the most common antiepileptic herbals demonstrated in tissue culture and preclinical models. From the review of the literature, it emerges that their effects are mediated via five distinct mechanisms: (1) reduction of membrane excitability through inhibition of cation channels, (2) improvement of mitochondrial functions with antioxidant effects, (3) enhancement in synaptic transmission mediated by GABAA receptors, (4) improvement of immune response with anti-inflammatory action, and (5) suppression of protein synthesis and metabolism. While some of the primary targets and action mechanisms of herbal anticonvulsants (1, 3) are shared with antiseizure pharmacotherapies, herbal leads also engage with distinct mechanisms (2, 4, and 5), suggesting new drug targets and opportunities for their integration with antiseizure medications. Addressing outstanding questions through research and in silico modeling should facilitate the future use of herbals as auxiliary therapy in epilepsy and guide the development of treatment of pharmacoresistant seizures through rigorous trials and regulatory approval.

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.

Effects of enzyme-inducing antiseizure medication on vitamin D dosing in adult veterans with epilepsy

BACKGROUND

The association of antiseizure medication (ASM) and bone density abnormalities has long been recognized; however, there remains a lack of consensus on efficacy and optimal vitamin D dosing in patients receiving enzyme inducing and non-inducing ASMs. The objective was to explore the relationship between ASMs and vitamin D supplementation requirements in a population of adult patients with epilepsy.

METHODS

Patients with a diagnosis of epilepsy receiving supplemental vitamin D were included in this retrospective chart review. All instances of 25-hydroxyvitamin D₃ (25-OHD) measured among those patients were compared between patients taking an enzyme inducing antiseizure medication (EIASM) to patients receiving ASM regimens only containing non-enzyme inducing antiseizure medications (NIASM). ASM use, prescription and over the counter (OTC) vitamin D use, 25-OHD plasma concentration, presence of chronic kidney disease (CKD), age, gender, and ethnicity were collected. Multiple linear regression was used to adjust for potentially confounding variables; the model included a cluster by participant term to account for repeated patients in the dataset.

RESULTS

There were 542 vitamin D levels evaluated from 172 unique patients. There was an 11.5 % higher absolute percent increase in patients who achieved a 25-OHD level over 30 ng/mL in the NIASM (p = 0.012). Patients on EIASMs were supplemented with an additional 508 units of vitamin D daily (95 %CI 136-878, p = 0.007). When adjusted for CKD, OTC vitamin D use, OTC multivitamin use, age, gender, and ethnicity, patients on EIASMs were supplemented with an additional 445 units of vitamin D (95 %CI -69 to 960, p = 0.089) compared to NIASM use.

CONCLUSIONS

Patients taking EIASMs had an increase in vitamin D deficiency and vitamin D supplementation suggesting that EIASMs impact vitamin D metabolism. Closer monitoring of vitamin D status in patients with epilepsy, especially those on EIASMs, is warranted. This evaluation suggests that for patients taking ASM, use of a lower dose OTC requires closer monitoring of vitamin D status in patients with epilepsy, especially those on EIASMs, is warranted. vitamin D agent may not be adequate.

Sexual functions in women with focal epilepsy: Relationship to demographic, clinical, hormonal and psychological variables

OBJECTIVES

Sexual dysfunctions [SDs] are common in women with epilepsy [WWE] but related studies were neglected in our locality. We aimed to determine the frequencies and severities of SDs and their clinical, hormonal and psychological determinants in WWE.

PATIENTS AND METHODS

This study included 120 adults [mean age: 36.35 ± 2.89yrs] with temporal [63.33 %] and frontal [36.67 %] lobe epilepsies and treated with carbamazepine [CBZ] [n = 60] or oxcarbazepine [OXC] [n = 60] for mean duration of 18.63 ± 4.33yrs. Patients were assessed using Female Sexual Function Index [FSFI] questionnaire, Beck Depression Inventory [BDI-II] and Hamilton Anxiety Rating Scale [HAM-A]. Total testosterone, sex hormone binding globulin [SHBG] and free androgen index [FAI] were measured to assess endocrinal status.

PATIENTS AND METHODS

This study included 120 adults [mean age: 36.35 ± 2.89yrs] with temporal [63.33 %] and frontal [36.67 %] lobe epilepsies and treated with carbamazepine [CBZ] [n = 60] or oxcarbazepine [OXC] [n = 60] for mean duration of 18.63 ± 4.33yrs. Patients were assessed using Female Sexual Function Index [FSFI] questionnaire, Beck Depression Inventory [BDI-II] and Hamilton Anxiety Rating Scale [HAM-A]. Total testosterone, sex hormone binding globulin [SHBG] and free androgen index [FAI] were measured to assess endocrinal status.

RESULTS

The majority had occasional/rare frequency of seizures [76.67 %] and well controlled on antiepileptic drugs [AEDs] [81.67 %]. Compared to healthy women, WWE had lower total testosterone and FAI and higher SHBG levels. Compared to women on CBZ, those on OXC had lower frequency and well controlled seizures on medication [P = 0.0001 for both], higher testosterone [P = 0.01] and FAI [P = 0.001] and lower SHBG [P = 0.001] levels. Compared to controls, WWE had significantly higher frequencies and severities of SDs [total sexual function, desire, arousal, lubrication, orgasm, satisfaction and pain] and depression and anxiety symptoms. OXC therapy was associated with lower SDs [FSFI: P = 0.033] and anxiety symptoms [P = 0.025] compared to CBZ therapy. In multiple logistic regression analyses, determinants of SDs were the higher seizures frequency, increasing severities of depression and anxiety but not lower androgen levels or type of epilepsy or AEDs.

CONCLUSIONS

Different aspects of SD and depression and anxiety symptoms were frequent in WWE. Determinants of SDs were the higher frequency of seizures and increasing severities of depression and anxiety. OXC had better control on seizures and thus lower frequencies and severities of SDs and depression and anxiety symptoms. Thus optimizing seizure control is important for psychological state and healthy sexual function in WWE.

Changes in hormone and lipid levels in male patients with focal seizures when switched from carbamazepine to lacosamide as adjunctive treatment to levetiracetam: A small phase IIIb, prospective, multicenter, open-label trial

Treatment with enzyme-inducing antiepileptic drugs (AEDs) such as carbamazepine (CBZ) can lead to changes in reproductive, endocrine, and lipid parameters, resulting in clinical symptoms for some patients. Previous studies indicate that these changes can be reversed by switching to a nonenzyme-inducing AED. Lacosamide is a newer-generation AED, not known to induce or strongly inhibit cytochrome P450 (CYP450) enzymes. In this phase IIIb, prospective, multicenter, open-label, single-arm trial (NCT01375374), the serum concentrations of CYP-related reproductive hormones, thyroid hormones, and lipids were assessed in otherwise healthy male patients with focal seizures (N=11), before and after a switch from CBZ (600-1200mg/day at baseline) to lacosamide (target dose: 400mg/day by the end of titration) as adjunctive treatment to the nonenzyme-inducing AED levetiracetam (LEV, stable dosage of >1000mg/day throughout). Cross titration took place over 4weeks, followed by an 8-week maintenance period. Serum measurements were conducted at baseline and at the end of maintenance. The median serum sex-hormone-binding globulin (SHBG) concentration was towards the higher end of the normal range at baseline and decreased following the switch (61.7 to 47.5nmol/L, N=10, p=0.027 by Wilcoxon signed-rank test). Free androgen index (100×testosterone/SHBG) and free thyroxine serum concentration increased (25.4 to 36.4 and 13.0 to 14.9pmol/L, respectively, both N=10 and p=0.002). At baseline, the median progesterone serum concentration was below the normal range (0.7nmol/L), whereas median cholesterol and low-density lipoprotein concentrations were above the normal range (5.5 and 3.6mmol/L, respectively). By the end of maintenance, all measured parameters were within the normal range. The safety and tolerability profile of lacosamide was consistent with that observed in previous studies. Furthermore, antiseizure efficacy appeared to be maintained, suggesting that deinduction of CYP enzymes following a switch from CBZ to lacosamide as adjunctive therapy to LEV is feasible within 8weeks and is associated with normalization of serum parameters.

Effect of antiepileptic drug therapy on thyroid hormones among adult epileptic patients: An analytical cross-sectional study

Objective:

The objective of the study was to evaluate and compare the effect of conventional and newer antiepileptic drugs (AEDs) on thyroid hormone levels in adult epileptic patients.

Methods:

A hospital-based, analytical cross-sectional study was conducted among the adult epileptic patients receiving conventional AEDs (Group 2) or newer AEDs (Group 3) for more than 6 months. Serum thyroid hormone levels including free triiodothyronine (fT₃), free thyroxine (fT₄), and thyroid stimulating hormone (TSH) were analyzed and the hormonal status was compared with healthy control subjects (Group 1).

Findings:

Sodium valproate and phenytoin were commonly used conventional AEDs; levetiracetam and topiramate were common among the newer drugs. There was a statistically significant decrease in serum fT₄ and increase in serum TSH levels (P < 0.0001) in patients on long-term therapy with conventional antiepileptic agents than in the control group. No significant change in thyroid hormone levels (fT₃, fT₄, and TSH; P = 0.68, 0.37, and 0.90, respectively) was observed with newer antiepileptics-treated patients when compared to control group. One-way analysis of variance followed by post hoc Dunnett's test was performed using SPSS version 17.0 software package.

Conclusion:

The present study showed that conventional AEDs have significant alteration in the thyroid hormone levels than the newer antiepileptics in adult epileptic patients.

Effects of chronic, parental pharmaceutical exposure on zebrafish (Danio rerio) offspring

In this study we explored how parental exposure to pharmaceuticals influences reproduction in offspring. Adult zebrafish (Danio rerio) were exposed for 6 weeks to 10 μgL(-1) of carbamazepine (CBZ) and gemfibrozil (GEM), two commonly prescribed drugs. Embryos were collected, reared in clean water until sexual maturity and then assessed for reproductive output, courtship, sperm function and organ histology. While 34% of the control pairs produced clutches, only 11% of the fish with CBZ exposed parents or 17% of the fish with GEM exposed parents produced clutches. Reciprocal crosses indicated that exposure in males had more profound reproductive effects. When a control F1 male was crossed with either a F1 female whose parents were CBZ or GEM exposed; no differences were observed in embryo production compared to controls. However, when a control F1 female was crossed with either a CBZ or GEM F1 male, 50% less embryos were produced. Male courtship was reduced in both CBZ and GEM F1 fish but the deficits in courtship displays were drug specific. Compared to control males, the sperm from GEM F1 males had shorter head lengths and midpieces whereas sperm from CBZ F1 males had longer midpieces. Although it remains unclear how specifically these morphological differences influenced sperm velocity, the sperm from GEM F1 males and from CBZ F1 males swam faster than the sperm of control F1 at 20s post activation. No significant differences were observed in the histology of the liver, kidney and gonads across treatment groups. These data are important as they show that chronic, low dose pharmaceutical exposure of parental fish is sufficient to cause significant reproductive effects in offspring.

Time-dependent changes in the serum levels of prolactin, nesfatin-1 and ghrelin as a marker of epileptic attacks young male patients

A relationship between hormones and seizures has been reported in animals and humans. Therefore, the purpose of this study was to investigate the association between serum levels of prolactin, nesfatin-1 and ghrelin measured different times after a seizure or non-epileptic event and compared with controls. The study included a total of 70 subjects, and of whom 18 patients had secondary generalized epilepsy (SGE), 16 patients had primary generalized epilepsy (PGE), 16 patients exhibited paroxysmal event (psychogenic) and 20 healthy males were control subjects. The first sample was taken within 5min of a seizure, with further samples taken after 1, 24, and 48h so long as the patient did not exhibit further clinically observable seizures; blood samples were taken once from control subjects. Prolactin was measured immediately using TOSOH Bioscience hormone assays. Nesfatin-1 and ghrelin peptides were measured using a commercial immunoassay kit. Patients suffering from focal epilepsy with secondary generalization and primary generalized epilepsy presented with significantly higher levels of serum prolactin and nesfatin-1 and lower ghrelin levels 5min, 1 and 24h after a seizure than patients presenting with paroxysmal events (psychogenic) and control subjects; the data were similar but not statistically significant after 48h. The present study suggests that increased serum prolactin and nesfatin-1 concentrations, decreased ghrelin concentrations could be used as markers to identify patients that have suffered a recent epileptic seizure or other paroxysmal event (psychogenic).

Influences of bone and mineral metabolism in epilepsy

INTRODUCTION

Patients with epilepsy are at increased risk for metabolic bone disease, low bone mineral density and fractures.

AREAS COVERED

This article reviews the predictors and mechanisms of bone loss in patients with epilepsy. It provides information regarding the basic bone biology, evidences of osteopathy with epilepsy and the potential mechanisms of its pathogenesis. This review shows that long-term use of antiepileptic drugs (AEDs) is associated with the risk of osteopathy. However, age, gender, low body mass, severity of epilepsy, co-morbid conditions, institutionalization and calcium and vitamin D deficiencies are additional and modified risk factors. AEDs may indirectly accelerate bone loss through hypovitaminosis D, hypocalcemia and hyperparathyroidism or reduce bone accrual through decreasing the levels of calcitonin, growth factors and vitamin K. Also, AEDs may directly accelerate osteoclastic (bone loss) and/or reduce osteoblastic (bone formation) activities, the main cells involved in bone remodeling.

EXPERT OPINION

Understanding the basic bone biology and the pathophysiology of the disturbed bone and mineral metabolism in epilepsy will aid in identification and monitoring of patients at risk and in planning appropriate prophylactic and therapeutic measures.

Alteration in chromogranin A, obestatin and total ghrelin levels of saliva and serum in epilepsy cases

This study was designed to measure the levels of chromogranin A (CgA), ghrelin and obestatin in serum and saliva (including CgA expression in healthy tissue) in epileptic patients to determine any significant differences between these patients and healthy controls. Samples were obtained from a total of 91 subjects: 10 newly-diagnosed primary generalized epilepsy (PGE) patients who had started treatment with valproic acid and phenytoin for seizure control; 18 PGE patients who were previously and currently receiving treatment with valproic acid and phenytoin for seizure control; 37 patients with partial epilepsy (PE) (simple, n=17 or complex, n=20) who had been and were still being treated with carbazebime for seizures; and 26 healthy controls. CgA immunoreactivity in healthy salivary gland was analyzed by immunohistochemistry and ELISA. The levels of CgA, total ghrelin and obestatin in serum and saliva were measured by ELISA. The results revealed that normal salivary gland produces its own CgA. Before treatment, CgA levels in saliva and serum were significantly greater in patients newly-diagnosed with PGE than controls. Ghrelin and CgA concentrations were also greater in PGE patients previously or currently treated with drugs, and in patients with simple or complex partial epilepsy (PE) previously or currently treated with drugs, than in healthy normal controls. In conclusion, salivary concentrations of CgA, ghrelin and obestatin were similar to their serum levels, so saliva might be a desirable alternative to serum for measuring these hormones because it is easy and painless to collect.

Thyroid hormones in children with epilepsy during long-term administration of carbamazepine and valproate

OBJECTIVE

This study evaluates the effects of long-term carbamazepine (CBZ) and valproate acid (VPA) therapy on thyroid function in epileptic children.

DESIGN

A prospective study performed in 32 newly diagnosed pediatric patients, subdivided into two groups: 18 patients treated with CBZ and 14 patients treated with VPA. Thirty-two sex- and age- matched subjects served as controls.

METHODS

Serum TSH, thyroxine (T(4)), triiodothyronine (T(3)), free thyroxine (fT(4)), free triiodothyronine (fT(3)), thyroid peroxidase antibodies (TPO-Ab), and thyroglobulin antibodies (TG-Ab) were evaluated at baseline and at the 3rd, 6th, and 12th month in all patients and in the control group. A TRH stimulation test was performed in all epileptic patients at baseline and at the 3rd, 6th, and 12th month evaluations while in controls only baseline assessment was carried out.

RESULTS

At baseline evaluation, thyroid function was normal in all epileptic children. After 3 months, CBZ-treated patients showed serum T(4) and fT(4) levels significantly lower than baseline evaluation and control subjects. Serum T(4) and fT(4) concentrations were unaffected by VPA monotherapy. Serum T(3) and fT(3) were normal in both CBZ-treated and VPA-treated patients. TRH test was normal in all patients. At 6th and 12th month evaluations, the same alterations were present in CBZ-treated patients while thyroid function remained normal in VPA-treated patients. TRH test responses were normal in all epileptic patients. TPO-Ab and TG-Ab were always absent in all patients.

CONCLUSIONS

Our data suggest that VPA monotherapy does not alter thyroid hormones. On the contrary, alterations of thyroid hormones occur in CBZ-treated children. However, the patients are euthyroid and thyroid hormone alterations are not associated with clinical or subclinical hypothyroidism.

Bone consequences of epilepsy and antiepileptic medications

Childhood and adolescence are critical periods of skeletal mineralization. Peak bone mineral density achieved by the end of adolescence determines the risk for later pathological fractures and osteoporosis. Chronic disease and medication often adversely affect bone health. Epilepsy is one of the most common neurological conditions occurring in persons under the age of 21. Epilepsy may affect bone in a number of ways. Restrictions of physical activity imposed by seizures, cerebral palsy or other coexisting comorbidities adversely affect bone health. It has been observed that treatment with phenytoin and phenobarbital can be associated with rickets. More recently, established agents such as carbamazepine and valproate have been shown to be associated with decreased bone mineral density. The literature related to bone health in pediatric epilepsy is reviewed.

Overview of treatment guidelines for epilepsy

The selection of an antiepileptic drug (AED) for the newly diagnosed patient is a critical decision because patients who are successfully treated usually respond to the first medication tried and changing the medication when treatment has been successful usually is avoided. However, the evidence needed to choose an AED wisely is incomplete, which is demonstrated by multiple practice guidelines that have been produced using systematic reviews of the medical literature. No individual AED or group of AEDs has been found to have superior efficacy for seizure control, nor can any AED or group of AEDs be considered first-line therapy. Nevertheless, the AEDs differ in their efficacy for different seizure types. Therefore, initial treatment should be based in part on the seizure type diagnosis or, at least, on whether the epilepsy syndrome is focal or generalized. The AEDs also differ in their safety, tolerability, and potential for pharmacologic interactions. These issues and the patient's comorbid conditions are additional bases for AED selection. The failure of AEDs to produce complete seizure control should lead to consideration of epilepsy surgery, especially for patients with mesial temporal lobe epilepsy. However, consensus does not exist regarding how many AEDs should be tried before determining the condition to be pharmacoresistant. Vagus nerve stimulation is an alternative treatment for patients who have pharmacoresistant epilepsy and choose not to have epilepsy surgery or have undergone unsuccessful epilepsy surgery. Infantile spasms are a seizure type requiring their own specific treatment. At present, the best evidence supports treatment with adrenocorticotropic hormone or vigabatrin.