Function In Epileptic Patients Research Articles

Immediate Effects of Vagal Nerve Stimulation in Drug-Resistant Epilepsy Revealed by Magnetoencephalographic Recordings.

Objective: Vagus nerve stimulation (VNS) has been a neuromodulatory option for treating drug-resistant epilepsy (DRE), but its mechanism remains unclear. To obtain insight into the mechanism by which VNS reduces epileptic seizures, the immediate effects of VNS in brain networks of DRE patients were investigated when the patients' vagal nerve stimulators were turned on. Methods: The brain network properties of 14 DRE patients with a vagal nerve stimulator and 14 healthy controls were evaluated using magnetoencephalography recordings for 6 main frequency bands. Results: Compared with healthy controls, DRE patients exhibited significant increases in functional connectivity in the theta, alpha, beta, and gamma bands and significant reductions in the small-world measure in the theta and beta bands. During periods when patients' vagal nerve stimulators were turned on, DRE patients showed significant reductions in functional connectivity in the theta and alpha bands and a significant increase in the small-world measure in the theta band when compared with periods when patients' vagal nerve stimulators were turned off. Conclusions: Our results indicate that the brain networks of DRE patients were pathologically hypersynchronous and instantaneous VNS can decrease the synchronization of brain networks of epileptic patients, which might play a key role in the mechanism by which VNS reduces epileptic seizures. In the theta band, instantaneous VNS can increase the network efficiency of DRE patients, and the increment in network efficiency may be helpful for improving brain cognitive function in epileptic patients. Impact statement For the first time, we investigated the immediate effects of vagus nerve stimulation (VNS) in the brain networks of drug-resistant epilepsy patients using magnetoencephalography. Our results show that instantaneous VNS can decrease the hypersynchronization of epileptic networks and increase the network efficiency of epileptic patients. Our results are helpful in understanding the mechanism of action by which VNS reduces epileptic seizures and improves the cognitive function in epileptic patients and the brain network reorganization caused by long-term VNS.

Cervical and ocular vestibular evoked myogenic potentials in epileptic patients

BackgroundVertigo and dizziness are very common complaints that may be related to epilepsy. The purpose of this study was to assess vestibulo-spinal and linear vestibulo-ocular function in epileptic patients in the inter ictal period. The current observational study was carried out in audio-vestibular unit Menoufia University. Subjects in the current study were divided into two groups: The control group included 30 normal individuals not complaining from any dizzy symptoms and the epileptic cases group included 30 epileptic patients. All subjects in the study were submitted to cervical and ocular vestibular evoked myogenic potential.ResultsThere was no significant difference between the control and epileptic group regarding the age and sex distribution. Sixty-seven percent of epileptic cases had dizzy symptoms. There was statistically significant difference in the latency and amplitude of c and o VEMP between the control and the epileptic group, 39/60 ears (65%) in the study group had cVEMP abnormalities, 32/60 ears (53%) had oVEMP abnormalities. Abnormal c and o VEMP were reported in 28/60 ears (46.7%). There was statistically significant relationship between VEMP abnormalities and duration of seizures, frequency of epileptic attacks, and type of therapy.ConclusionVestibular abnormalities were frequently reported in epileptic patients in the current study which may be related to the severity and control of epilepsy.

Significant Association of Antiepileptic Drug Polytherapy with Decreased FT4 Levels in Epileptic Patients.

Epileptic patients have to continue anti-epileptic drugs (AED) over a long period of time which can have deleterious effects on the endocrine system including the thyroid hormones with rare check. Risk factors for the development of thyroid dysfunction are still unclear. Therefore the aim of study was to evaluate thyroid functions in epileptic patients receiving anti-epileptic drugs (AED) as monotherapy and polytherapy and to determine potential risk of low thyroid function in epileptic patients receiving treatment. This cross-sectional study included 100 epilepsy patients more than 12years of age. Serum levels of free thyroxin (FT4), free triiodothyronine (FT3), and thyroid stimulating hormone (TSH) were evaluated in all subjects in addition to serum AED levels. TSH levels were found to be significantly higher in the polytherapy subgroup (p < 0.05) in comparison to the monotherapy group. 44% of the patients in the VPA monotherapy group had raised TSH levels and 41.2% of the patients on CBZ had low FT4. A significant negative correlation was observed between CBZ and FT4 (p < 0.05). Female sex and old age were additional risk factors detected for deranged thyroid function. Female patients with epilepsy, an older age and AED polytherapy were found to be associated with a higher risk of thyroid dysfunction. Thus, Thyroid function in these patients should be monitored closely. In conclusion, we observed significant changes in thyroid hormone levels in patients receiving antiepileptic treatment in both monotherapy and polytherapy. Elevated CBZ levels were significantly associated with decreased FT4 levels.

Video head impulse test in epileptic patients

ObjectivesTo assess the vestibulo-ocular function in epileptic patients in the interictal period.BackgroundVertigo or dizziness are common symptoms with epileptic seizures.Patients and methodsThis is a cross-sectional study. The participants included in this study were divided into two groups. The control group consisted of 40 normal participants not complaining of any dizzy symptoms, with an age range of 20–40 years, and the study group (epileptic cases group) consisted of 40 epileptic patients, with age range of 20–40 years. All participants were subjected to vestibular assessment in the form of videonystagmography and video head impulse test (vHIT).ResultsThere was no significant statistical difference between both groups regarding age (P = 0.17, Student t test) and sex distribution (P = 0.65, χ2 test). A total of 25 (62.5%) epileptic patients had vestibular symptoms. On videonystagmography, saccadic intrusions in pursuit test were reported in four (10%) epileptic patients, and seven (17.5%) epileptic patients had abnormal velocity in the saccade test; there was a significant statistical difference between both groups regarding the velocity of the saccade test (P = 0.02, Student t test). On vHIT, there was a significant statistical difference between both groups regarding lateral canal gain (P = 0.001, Student t test). A total of 29 (72.5%) patients in the study group had an abnormal gain in at least one canal of the six semicircular canals. Eight (20%) patients in the study group had low gain, and 21/40 (52.5%) patients had high gain. There was a significant statistical relationship between vestibular abnormalities and type of epilepsy, as well as EEG findings.ConclusionVestibular system may be affected with epilepsy; high gain was the most frequently encountered abnormality in the vHIT.

The P300 Event-Related Potential Component and Cognitive Impairment in Epilepsy: A Systematic Review and Meta-analysis

Background: Epilepsy is one of the most prevalent chronic brain diseases worldwide and is often accompanied by cognitive impairment. Event-related potentials (ERPs) are an objectively non-invasive approach for studying information processing and cognitive functions in the brain. The P300 is an important and extensively explored late component of ERPs that has been widely applied to assess cognitive function in epilepsy in previous studies. However, consistent conclusions have not yet been reached for various reasons.Objective: We conducted a comprehensive systematic review and meta-analysis of P300-related studies to assess the latency and amplitude of the P300 in epileptic patients.Methods: PubMed, EMBASE, and Cochrane Library databases were systematically searched for eligible studies. The standard mean difference (SMD) and the 95% confidence interval (CI) were calculated as the effect size of the P300 component.Results: The main results of the present meta-analysis indicated that epileptic patients have a longer P300 latency and a lower P300 amplitude than controls. Subgroup analysis based on age group demonstrated that these differences can be observed in both children and adult patients compared with healthy controls. In addition, the P300 latency was longer in patients with the five main types of epileptic seizures than in controls.Conclusion: This study revealed that epileptic patients have abnormalities in the P300 component, which may reflect deficits in cognitive function. Thus, the P300 may be a potential objective approach for evaluating cognitive function in epileptic patients.

The effects of acetyl L-carnitine treatment on cognitive and memory function in epileptic patients under antiepileptic medication

The effects of acetyl L-carnitine treatment on cognitive and memory function in epileptic patients under antiepileptic medication

An effective assessment of valproate sodium-induced hepatotoxicity with UPLC-MS and (1)HNMR-based metabonomics approach.

Valproate sodium is one of the most prescribed antiepileptic drugs. However, valproate sodium has various side effects, especially its toxicity on liver. Current markers for toxicity reflect mostly the late stages of tissue damage; thus, more efficient methods for toxicity evaluation are desired. To evaluate the toxicity of valproate sodium on liver, we performed both UPLC-MS and (1)HNMR-based metabonomics analysis of serum samples from 34 epileptic patients (age: 42.0±18.6, 18 male/16 female) after valproate sodium treatment. Compared to conventional markers, the serum metabolic profiles provided clear distinction of the valproate sodium induced normal liver function and abnormal liver function in epileptic patients. Through multivariate statistical analysis, we identified marker metabolites associated with the hepatotoxicity induced by valproate sodium, such as glucose, lactate, acetoacetate, VLDL/LDL, lysophosphatidylcholines, phosphatidylcholines, choline, creatine, amino acids, N-acetyl glycoprotein, pyruvate and uric acid. This metabonomics approach may provide effective way to evaluate the valproate sodium-induced toxicity in a manner that can complement current measures. This approach is expected to find broader application in other drug-induced toxicity assessment.

A controlled study of vigabatrin and visual abnormalities

AIMSTo assess the visual function in epileptic patients who have received vigabatrin; to compare this with the visual function in similar epileptic patients who have never received vigabatrin; to investigate...

Thyroid Function in Epileptic Patients Treated With Carbamazepine

The effects of carbamazepine monotherapy on thyroid function were evaluated in patients with epilepsy. A prospective follow-up of 40 patients with recently diagnosed epilepsy was carried out to evaluate the short-term effects. Thirty-three patients receiving long-term carbamazepine therapy (average duration, 4.2 years) and 34 healthy control subjects were studied. Levels of serum thyroxine, free thyroxine, and thyroxine binding globulin were decreased after both 2 and 12 months of therapy with carbamazepine. Low serum thyroxine and free thyroxine concentrations were also found after long-term monotherapy with carbamazepine. Baseline thyrotropin did not change during carbamazepine therapy, but thyrotropin responses to thyrotropin-releasing hormone rose slightly. No correlation was found between serum carbamazepine and hormone concentrations. The results not only support previous suggestions that carbamazepine induces the hepatic clearance of thyroid hormones but also suggest that carbamazepine may have an inhibitory effect at the hypothalamic level.

Concentration-effect relationships with carbamazepine and its epoxide on psychomotor and cognitive function in epileptic patients.

A battery of psychometric tests was administered to 85 patients with epilepsy, of whom 26 were untreated, 40 received carbamazepine monotherapy and 19 took carbamazepine with another anticonvulsant. Carbamazepine alone had little effect on performance, but carbamazepine polypharmacy produced significant impairment. Increasing concentrations of carbamazepine (four tests) and its active metabolite, carbamazepine 10,11 epoxide (seven tests), correlated with decreasing performance in the monotherapy patients.

Effects of Valproate on Mitochondrial Function in Epileptic Patients

Effects of Valproate on Mitochondrial Function in Epileptic Patients

Pituitary and adrenal function in epileptic patients.

ACTH and cortisol were measured simultaneously in plasma samples obtained every 5 min from subjects at two different diurnal times. In the first study adrenocorticotropic hormone (ACTH) mean concentration and secretory rate were elevated in anticonvulsant drug-treated temporal lobe epileptic patients in comparison to anticonvulsant drug-treated patients with pseudoseizures. Cortisol mean concentrations and secretory rate were similar in these groups of subjects. In the second study, mean ACTH concentration and secretory rate were higher in temporal lobe epileptic patients than in normal controls. Both measures of ACTH secretion were similar in post-temporal lobectomy patients and normal controls. Mean cortisol concentration and secretory rates were highest in the temporal lobe epileptic patients, lowest in normal controls, and intermediate in post-temporal lobectomy patients. We conclude that ACTH and cortisol secretion is abnormal in temporal lobe epileptic patients. Temporal lobectomy restores abnormal ACTH secretion to normal whether or not seizures are controlled. The absence of ACTH changes in the pseudoseizure patients suggests that these changes are not drug induced. Cortisol secretion is similar in temporal lobe epileptic patients and pseudoseizure patients, suggesting a direct effect of the drugs upon the adrenal cortex.