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Epilepsia Apr 2024The intricate neuroanatomical structure of the cerebellum is of longstanding interest in epilepsy, but has been poorly characterized within the current corticocentric...
OBJECTIVE
The intricate neuroanatomical structure of the cerebellum is of longstanding interest in epilepsy, but has been poorly characterized within the current corticocentric models of this disease. We quantified cross-sectional regional cerebellar lobule volumes using structural magnetic resonance imaging in 1602 adults with epilepsy and 1022 healthy controls across 22 sites from the global ENIGMA-Epilepsy working group.
METHODS
A state-of-the-art deep learning-based approach was employed that parcellates the cerebellum into 28 neuroanatomical subregions. Linear mixed models compared total and regional cerebellar volume in (1) all epilepsies, (2) temporal lobe epilepsy with hippocampal sclerosis (TLE-HS), (3) nonlesional temporal lobe epilepsy, (4) genetic generalized epilepsy, and (5) extratemporal focal epilepsy (ETLE). Relationships were examined for cerebellar volume versus age at seizure onset, duration of epilepsy, phenytoin treatment, and cerebral cortical thickness.
RESULTS
Across all epilepsies, reduced total cerebellar volume was observed (d = .42). Maximum volume loss was observed in the corpus medullare (d = .49) and posterior lobe gray matter regions, including bilateral lobules VIIB (d = .47), crus I/II (d = .39), VIIIA (d = .45), and VIIIB (d = .40). Earlier age at seizure onset ( = .05) and longer epilepsy duration ( = .06) correlated with reduced volume in these regions. Findings were most pronounced in TLE-HS and ETLE, with distinct neuroanatomical profiles observed in the posterior lobe. Phenytoin treatment was associated with reduced posterior lobe volume. Cerebellum volume correlated with cerebral cortical thinning more strongly in the epilepsy cohort than in controls.
SIGNIFICANCE
We provide robust evidence of deep cerebellar and posterior lobe subregional gray matter volume loss in patients with chronic epilepsy. Volume loss was maximal for posterior subregions implicated in nonmotor functions, relative to motor regions of both the anterior and posterior lobe. Associations between cerebral and cerebellar changes, and variability of neuroanatomical profiles across epilepsy syndromes argue for more precise incorporation of cerebellar subregional damage into neurobiological models of epilepsy.
Topics: Adult; Humans; Epilepsy, Temporal Lobe; Phenytoin; Cross-Sectional Studies; Epileptic Syndromes; Cerebellum; Seizures; Magnetic Resonance Imaging; Atrophy
PubMed: 38411286
DOI: 10.1111/epi.17881 -
Problemy Endokrinologii Feb 2024Insulinoma is the most common hormonally active neuroendocrine tumor (NET) of the pancreas. In recent years, there has been a trend towards an increase in the incidence... (Review)
Review
RELEVANCE
Insulinoma is the most common hormonally active neuroendocrine tumor (NET) of the pancreas. In recent years, there has been a trend towards an increase in the incidence of NET especially insulinoma.
AIM
Summarizing and analyzing current data on various approaches to the treatment of insulinoma. Our review includes a comprehensive assessment of the advantages and disadvantages of currently available insulinoma treatment methods in comparison with past experience, as well as a review of promising methods that are not currently widely used.
MATERIALS AND METHODS
Analysis of literature from such databases as scientific electronic library elibrary.ru, Pubmed, Google Scholar, MedLine, Scopus and Web of Science.
RESULTS
The most common treatment for insulinoma is surgery. For patients with high operative risk, alternative methods such as alcohol ablation, radiofrequency ablation, and tumor embolization may be used. Medications include the use of somatostatin analogues, diazoxide. The literature describes the potential benefit of the use of beta-blockers, phenytoin, glucagon, however, in clinical trials, these drugs have not demonstrated a significant effect. For the treatment of malignant and metastatically advanced insulinoma, targeted therapy (primarily Everolimus), chemotherapy, as well as embolization (including chemoembolization, radioembolization), radiofrequency ablation (RFA), microwave ablation and cryoablation, ultrasound ablation (HIFU), laser ablation, brachytherapy, irreversible electroporation are used.
CONCLUSION
The study of new drugs is an important task for scientists, among medications the most promising are new generations of somatostatin analogues, targeted drugs and chemotherapy drugs. The rare frequency of insulinoma makes it difficult to conduct randomized controlled trials and prospective studies. That is why physicians and scientists need to maintain close contacts with each other and take into account the experience of treating each patient with such disease, which will help develop effective treatment algorithms in the future.
Topics: Humans; Insulinoma; Prospective Studies; Neuroendocrine Tumors; Apudoma; Pancreatic Neoplasms; Somatostatin
PubMed: 38433541
DOI: 10.14341/probl13281 -
Metabolites Jul 2023The thyroid hormones (THs) regulate various physiological mechanisms in mammals, such as cellular metabolism, cell structure, and membrane transport. The therapeutic...
The thyroid hormones (THs) regulate various physiological mechanisms in mammals, such as cellular metabolism, cell structure, and membrane transport. The therapeutic drugs propylthiouracil (PTU) and phenytoin are known to induce hypothyroidism and decrease blood thyroid hormone levels. To analyze the impact of these two drugs on systemic metabolism, we focused on metabolic changes after treatment. Therefore, in a rat model, the metabolome of thyroid and liver tissue as well as from the blood plasma, after 2-week and 4-week administration of the drugs and after a following 2-week recovery phase, was investigated using targeted LC-MS/MS and GC-MS. Both drugs were tested at a low dose and a high dose. We observed decreases in THs plasma levels, and higher doses of the drugs were associated with a high decrease in TH levels. PTU administration had a more pronounced effect on TH levels than phenytoin. Both drugs had little or no influence on the metabolomes at low doses. Only PTU exhibited apparent metabolome alterations at high doses, especially concerning lipids. In plasma, acylcarnitines and triglycerides were detected at decreased levels than in the controls after 2- and 4-week exposure to the drug, while sphingomyelins and phosphatidylcholines were observed at increased levels. Interestingly, in the thyroid tissue, triglycerides were observed at increased concentrations in the 2-week exposure group to PTU, which was not observed in the 4-week exposure group and in the 4-week exposure group followed by the 2-week recovery group, suggesting an adaptation by the thyroid tissue. In the liver, no metabolites were found to have significantly changed. After the recovery phase, the thyroid, liver, and plasma metabolomic profiles showed little or no differences from the controls. In conclusion, although there were significant changes observed in several plasma metabolites in PTU/Phenytoin exposure groups, this study found that only PTU exposure led to adaptation-dependent changes in thyroid metabolites but did not affect hepatic metabolites.
PubMed: 37512556
DOI: 10.3390/metabo13070847 -
International Journal of Molecular... Dec 2023Experimental studies reveal that caffeine (trimethylxanthine) at subconvulsive doses, distinctly reduced the anticonvulsant activity of numerous antiseizure medications... (Review)
Review
Experimental studies reveal that caffeine (trimethylxanthine) at subconvulsive doses, distinctly reduced the anticonvulsant activity of numerous antiseizure medications (ASMs) in rodents, oxcarbazepine, tiagabine and lamotrigine being the exceptions. Clinical data based on low numbers of patients support the experimental results by showing that caffeine (ingested in high quantities) may sharply increase seizure frequency, considerably reducing the quality of patients' lives. In contrast, this obviously negative activity of caffeine was not found in clinical studies involving much higher numbers of patients. ASMs vulnerable to caffeine in experimental models of seizures encompass carbamazepine, phenobarbital, phenytoin, valproate, gabapentin, levetiracetam, pregabalin and topiramate. An inhibition of R-calcium channels by lamotrigine and oxcarbazepine may account for their resistance to the trimethylxanthine. This assumption, however, is complicated by the fact that topiramate also seems to be a blocker of R-calcium channels. A question arises why large clinical studies failed to confirm the results of experimental and case-report studies. A possibility exists that the proportion of patients taking ASMs resistant to caffeine may be significant and such patients may be sufficiently protected against the negative activity of caffeine.
Topics: Humans; Lamotrigine; Oxcarbazepine; Caffeine; Topiramate; Anticonvulsants; Seizures; Calcium Channels
PubMed: 38139396
DOI: 10.3390/ijms242417569 -
PloS One 2023Phosphodiesterase 5 inhibitors (PDE5i) are the first line treatment for erectile dysfunction; however, several articles and case reports have shown central nervous...
BACKGROUND
Phosphodiesterase 5 inhibitors (PDE5i) are the first line treatment for erectile dysfunction; however, several articles and case reports have shown central nervous system effects, that can cause seizures in susceptible patients. This study aims to describe the changes caused by the use of Sildenafil and Tadalafil through the analysis of abnormalities expressed in the electrocorticogram (ECoG) of rats and evaluate the seizure threshold response and treatment of seizures with anticonvulsants.
MATERIALS AND METHODS
The study used 108 rats (Wistar). Before surgery for electrode placement in dura mater, the animals were randomly separated into 3 experiments for electrocorticogram analysis. Experiment 1: ECoG response to using PD5i (Sildenafil 20mg/kg and Tadalafil 2.6mg/kg p.o.). Experiment 2: ECoG response to the use of PD5i in association with Pentylenetetrazole (PTZ-30 mg/kg i.p.), a convulsive model. Experiment 3: ECoG response to anticonvulsant treatment (Phenytoin, Phenobarbital and Diazepam) of seizures induced by association IPDE5 + PTZ. All recordings were made thirty minutes after administration of the medication and analyzed for ten minutes, only once. We considered statistical significance level of *p<0.05, **p<0.01 and ***p < 0.001.
RESULTS
After administration of Sildenafil and Tadalafil, there were increases in the power of recordings in the frequency bands in oscillations in alpha (p = 0.0920) and beta (p = 0.602) when compared to the control group (p<0.001). After the use of Sildenafil and Tadalafil associated with PTZ, greater potency was observed in the recordings during seizures (p<0.001), however, the Sildenafil group showed greater potency when compared to Tadalafil (p<0.05). Phenobarbital and Diazepam showed a better response in controlling discharges triggered by the association between proconvulsant drugs.
CONCLUSIONS
PDE5i altered the ECoG recordings in the rats' motor cortexes, demonstrating cerebral asynchrony and potentiating the action of PTZ. These findings demonstrate that PDE5i can lower the seizure threshold.
Topics: Animals; Male; Rats; Anticonvulsants; Diazepam; Pentylenetetrazole; Phenobarbital; Phosphodiesterase 5 Inhibitors; Rats, Wistar; Seizures; Sildenafil Citrate; Tadalafil
PubMed: 38033148
DOI: 10.1371/journal.pone.0294754 -
Cureus Nov 2023Epilepsy is not a common cause of morbidity in pregnancy. It has widespread effects on maternal and fetal health necessitating adequate control of seizures. Many...
Epilepsy is not a common cause of morbidity in pregnancy. It has widespread effects on maternal and fetal health necessitating adequate control of seizures. Many anti-seizure medications (ASM) have teratogenic effects on the fetus. We report a case of severe fetal hydantoin syndrome resulting in life-threatening major congenital anomalies. The mother was on phenytoin for the last three years and the pregnancy was not registered. We discuss various features of fetal hydantoin syndrome and the ideal management of epilepsy in pregnancy in brief.
PubMed: 38161950
DOI: 10.7759/cureus.49663 -
Assessment of the accuracy of estimated free phenytoin concentrations in a mixed patient population.European Journal of Hospital Pharmacy :... Oct 2023Phenytoin is an anti-epileptic drug that has a narrow therapeutic index, and therefore requires therapeutic drug monitoring. Only the free fraction is pharmacologically...
OBJECTIVES
Phenytoin is an anti-epileptic drug that has a narrow therapeutic index, and therefore requires therapeutic drug monitoring. Only the free fraction is pharmacologically active, and in some cases, accurate determination of the free phenytoin concentration may be essential to prevent phenytoin toxicity. Although it is possible to measure free phenytoin concentration, often only the total concentration is measured, with equations used to estimate the free fraction. Several equations are quoted in the literature with no overall consensus with regard to accuracy. This study aimed to assess the correlation between total and free phenytoin in a mixed patient population, and to compare the accuracy of several different equations used to estimate the free phenytoin concentration.
METHODS
Fifty-one serum samples were analysed for total phenytoin, free phenytoin and albumin. The measured free phenytoin concentrations were compared against those estimated using five selected equations, identified through a literature search.
RESULTS
This study showed poor correlation between the total and measured free phenytoin concentrations, and between the estimated and measured free concentrations. The overall correlation was concentration-dependent, but a correction factor could not be applied to improve the accuracy consistently. The equations assessed showed wide variability between the estimated and measured free phenytoin concentrations, with several showing a clinically significant negative bias when compared with the measured free fraction.
DISCUSSION
This study highlights the disparity of the free phenytoin concentrations generated by the equations. Underestimation of free phenytoin concentrations using these equations may result in phenytoin toxicity, bringing into question the safety of using calculated values for patient management in place of physical measurement of free phenytoin concentration by ultra-performance liquid chromatography tandem mass spectrometry.
PubMed: 37802642
DOI: 10.1136/ejhpharm-2023-003878 -
Seizure May 2024Seizures represent a significant comorbidity in children with acute encephalitis syndrome (AES). Despite this, there is a notable absence of randomized controlled trials... (Randomized Controlled Trial)
Randomized Controlled Trial
Efficacy and safety of phenytoin and levetiracetam for acute symptomatic seizures in children with acute encephalitis syndrome: an open label, randomised controlled trial.
INTRODUCTION
Seizures represent a significant comorbidity in children with acute encephalitis syndrome (AES). Despite this, there is a notable absence of randomized controlled trials (RCTs) directly comparing antiseizure medications (ASMs) in children with AES.
MATERIALS AND METHODS
This RCT aimed to assess the efficacy and safety of phenytoin and levetiracetam in controlling seizures among children with AES. Both ASMs were administered with a loading followed by maintenance dose. After a 12-week period, children exhibiting a normal electroencephalogram and no seizure recurrence underwent tapering and discontinuation of ASM. Clinical follow-up occurred daily for the first week, and subsequently at 4, 12, and 24 weeks, evaluating seizure recurrence, incidence of status epilepticus, cognition, behavior, functional status, ASM acquisition cost, and adverse effects.
RESULTS
A total of 100 children (50 in each group) were enrolled. Within the first week, 5 and 3 children in the phenytoin and levetiracetam groups expired. Up to 1 week or death (whichever occurred earliest), 46 (92 %) and 44 (88 %) children remained seizure-free. Intention-to-treat analysis for both best and worst-case scenarios showed insignificant differences (p=0.52 and 1.0). No children experienced seizure recurrence after 1 week in either group. The number of patients with breakthrough status epilepticus, need for mechanical ventilation, duration of hospital stay, presence of epileptiform abnormalities in repeat electroencephalogram at 12 weeks, functional outcomes at 1, 12, and 24 weeks, as well as cognition and behavioral profiles at 24 weeks, were comparable in both groups (p>0.05 for all). However, the incidence of treatment-emergent adverse events (TEAEs) causally related to study medications was significantly higher in the phenytoin group (p=0.04).
CONCLUSION
Levetiracetam and phenytoin are comparable in efficacy in terms of achieving clinical seizure control in children with acute encephalitis syndrome, although levetiracetam group demonstrated fewer adverse effects.
Topics: Humans; Levetiracetam; Phenytoin; Anticonvulsants; Female; Male; Child, Preschool; Seizures; Child; Treatment Outcome; Infant; Acute Febrile Encephalopathy; Electroencephalography
PubMed: 38678766
DOI: 10.1016/j.seizure.2024.04.015 -
Journal of Emergencies, Trauma, and... 2024Phenytoin is one of the commonly used anti.seizure medications in nontraumatic seizures. However, its utility and safety in young patients with traumatic brain injury...
INTRODUCTION
Phenytoin is one of the commonly used anti.seizure medications in nontraumatic seizures. However, its utility and safety in young patients with traumatic brain injury (TBI) for the prevention of early-onset seizures (EOS) are debatable. We sought to explore the use of phenytoin as a seizure prophylaxis following TBI. We hypothesized that administering phenytoin is not effective in preventing EOS after TBI.
METHODS
This was a retrospective observational study conducted on adult TBI patients. EOS was defined as a witnessed seizure within a week postinjury. Data were compared as phenytoin versus no-phenytoin use, EOS versus no-EOS, and among TBI severity groups.
RESULTS
During 1 year, 639 TBI patients were included with a mean age of 32 years; of them, 183 received phenytoin as seizure prophylaxis, and 453 received no prophylaxis medication. EOS was documented in 13 (2.0%) patients who received phenytoin, and none had EOS among the nonphenytoin group. The phenytoin group was more likely to have a higher Marshall Score ( = 0.001), lower Glasgow Coma Scale (GCS) ( = 0.001), EOS ( = 0.001), and higher mortality ( = 0.001). Phenytoin was administrated for 15.2%, 43.2%, and 64.5% of mild, moderate, and severe TBI patients, respectively. EOS and no-EOS groups were comparable for age, gender, mechanism of injury, GCS, Marshall Score, serum phenytoin levels, liver function levels, hospital stay, and mortality. Multivariable logistic regression analysis showed that low serum albumin (odds ratio [OR] 0.81; 95% confidence interval [CI] 0.676.0.962) and toxic phenytoin level (OR 43; 95% CI 2.420.780.7) were independent predictors of EOS.
CONCLUSIONS
In this study, the prophylactic use of phenytoin in TBI was ineffective in preventing EOS. Large-scale matched studies and well-defined hospital protocols are needed for the proper utility of phenytoin post-TBI.
PubMed: 38681877
DOI: 10.4103/jets.jets_93_23 -
The American Journal of Emergency... Jul 2023Tacrolimus is commonly used for immunosuppression in patients following solid organ transplantation. For transplant patients with COVID-19 infection, early treatment is...
Tacrolimus is commonly used for immunosuppression in patients following solid organ transplantation. For transplant patients with COVID-19 infection, early treatment is indicated due to the risk of progression to severe disease. However, the first line agent, nirmatrelvir/ritonavir, has multiple drug-drug interactions. We report a case of tacrolimus toxicity in a patient with a history of renal transplant due to enzyme inhibition related to nirmatrelvir/ritonavir. An 85-year-old woman with a history of multiple comorbidities presented to the emergency department (ED) with weakness, increasing confusion, poor oral intake, and inability to walk. She had been recently diagnosed with COVID-19 infection and was prescribed nirmatrelvir/ritonavir due to her underlying comorbidities and immune suppression. In the ED, she was dehydrated and had an acute kidney injury (creatinine 2.1 mg/dL, up from a baseline of 0.8 mg/dL). The tacrolimus concentration on initial labs was 143 ng/mL (5-20 ng/mL) and it continued to rise despite being held, to a peak of 189 ng/mL on hospital day 3. The patient was treated with phenytoin for enzyme induction and the tacrolimus concentration began to fall. She was discharged to a rehabilitation facility after a 17 day hospitalization. ED physicians must be cognizant of drug-drug interactions when prescribing nirmatrelvir/ritonavir and evaluating patients recently treated with the drug to identify toxicity due to these interactions.
Topics: Humans; Female; Aged, 80 and over; Ritonavir; COVID-19; COVID-19 Drug Treatment; Tacrolimus; Antiviral Agents
PubMed: 37173153
DOI: 10.1016/j.ajem.2023.04.045