Review of pharmacogenetics of antiseizure medications: focusing on genetic variants of mechanistic targets.

Antiseizure medications (ASMs) play a central role in seizure management, however, unpredictability in the response to treatment persists, even among patients with similar seizure manifestations and clinical backgrounds. An objective biomarker capable of reliably predicting the response to ASMs would profoundly impact epilepsy treatment. Presently, clinicians rely on a trial-and-error approach when selecting ASMs, a time-consuming process that can result in delays in receiving alternative non-pharmacological therapies such as a ketogenetic diet, epilepsy surgery, and neuromodulation therapies. Pharmacogenetic studies investigating the correlation between ASMs and genetic variants regarding their mechanistic targets offer promise in predicting the response to treatment. Sodium channel subunit genes have been extensively studied along with other ion channels and receptors as targets, however, the results have been conflicting, possibly due to methodological disparities including inconsistent definitions of drug response, variations in ASM combinations, and diversity of genetic variants/genes studied. Nonetheless, these studies underscore the potential effect of genetic variants on the mechanism of ASMs and consequently the prediction of treatment response. Recent advances in sequencing technology have led to the generation of large genetic datasets, which may be able to enhance the predictive accuracy of the response to ASMs.

The Genetics of Primary Familial Brain Calcification: A Literature Review.

Primary familial brain calcification (PFBC), also known as Fahr's disease, is a rare inherited disorder characterized by bilateral calcification in the basal ganglia according to neuroimaging. Other brain regions, such as the thalamus, cerebellum, and subcortical white matter, can also be affected. Among the diverse clinical phenotypes, the most common manifestations are movement disorders, cognitive deficits, and psychiatric disturbances. Although patients with PFBC always exhibit brain calcification, nearly one-third of cases remain clinically asymptomatic. Due to advances in the genetics of PFBC, the diagnostic criteria of PFBC may need to be modified. Hitherto, seven genes have been associated with PFBC, including four dominant inherited genes (SLC20A2, PDGFRB, PDGFB, and XPR1) and three recessive inherited genes (MYORG, JAM2, and CMPK2). Nevertheless, around 50% of patients with PFBC do not have pathogenic variants in these genes, and further PFBC-associated genes are waiting to be identified. The function of currently known genes suggests that PFBC could be caused by the dysfunction of the neurovascular unit, the dysregulation of phosphate homeostasis, or mitochondrial dysfunction. An improved understanding of the underlying pathogenic mechanisms for PFBC may facilitate the development of novel therapies.

Risk factors for seizures after cranioplasty.

PURPOSE: Cranioplasty can improve a patient's psychosocial and cognitive functions after decompressive craniectomy, however seizures are a common complication after cranioplasty. The risk factors for early and late seizures after cranioplasty are unclear. This study is to evaluate the risk factors for early and late seizure after cranioplasty. METHODS: Two hundred and thirty-eight patients who received cranioplasty following craniectomy between January 2012 and December 2014 were included in this study. The risk factors of the patients with early and late post-cranioplasty seizures were compared to those with no post-cranioplasty seizures. RESULTS: Seizures (73/238, 30.3%) were the most common complication after cranioplasty. Of these 73 patients, 17 (7.1%) had early post-cranioplasty seizures and 56 (23.5%) had late post-cranioplasty seizures. Early post-cranioplasty seizures were related to a longer interval between craniectomy and cranioplasty (P = 0.006), artificial materials (P < 0.001), and patients with late post-craniectomy seizures (P = 0.001). Late post-cranioplasty seizures were related to the presence of neurological deficits (P = 0.042). After stepwise logistic regression analysis, a longer interval between craniectomy and cranioplasty (P = 0.012; OR: 1.004, 95% CI: 1.001-1.007) and late post-craniectomy seizures (P = 0.033; OR: 4.335, 95% CI: 1.127-16.675) were independently associated with early post-cranioplasty seizures. CONCLUSION: Delayed cranioplasty procedures and seizures before cranioplasty were significantly associated with early post-cranioplasty seizures. Further studies are warranted to investigate whether early surgery after craniectomy can reduce the risk of early post-cranioplasty seizures.

Status epilepticus associated with pregnancy: A cohort study.

BACKGROUND: Status epilepticus (SE) is a neurological emergency associated with a high mortality rate and long-term cognitive sequelae. Status epilepticus in pregnancy poses a tremendous threat to both mother and fetus, making a correct diagnosis and treatment a challenging task for clinicians. The prevalence, underlying etiology, and outcomes of pregnancy-related SE remain largely unknown. METHODS: We retrospectively studied all SE episodes (n=366) in patients admitted to our neurological ICU over a period of 8.5years. The patients who developed SE during pregnancy and within 6months after delivery were considered to have pregnancy-related SE. Patients with eclampsia were not included as they were usually cared for in our obstetric unit. RESULTS: Seven patients with pregnancy-related SE were identified (2.1% of all cases of SE), with the majority (85%) occurring de novo except for one patient who had a previous history of epilepsy-related SE due to withdrawal of antiepileptic medication. In terms of etiology, limbic encephalitis and cerebral venous sinus thrombosis were the two main etiologies of de novo SE associated with pregnancy. The overall mortality rate was 28.5% at discharge, and poor outcomes were especially noted in the patients with limbic encephalitis compared to other etiologies. CONCLUSIONS: Pregnancy-associated SE is rare and predominantly occurs in patients without a history of epilepsy. An autoimmune etiology should be considered in pregnant patients with de novo SE, which was associated with poor outcomes. Thorough investigations and prompt treatment according to the etiology may be required to improve the final outcomes of both mother and fetus.

Clinical significance of circulating vascular cell adhesion molecule-1 to white matter disintegrity in Alzheimer's dementia.

Endothelial dysfunction leads to worse cognitive performance in Alzheimer's dementia (AD). While both cerebrovascular risk factors and endothelial dysfunction lead to activation of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin, it is not known whether these biomarkers extend the diagnostic repertoire in reflecting intracerebral structural damage or cognitive performance. A total of 110 AD patients and 50 age-matched controls were enrolled. Plasma levels of VCAM-1, ICAM-1 and E-selectin were measured and correlated with the cognitive performance, white matter macro-structural changes, and major tract-specific fractional anisotropy quantification. The AD patients were further stratified by clinical dementia rating score (mild dementia, n=60; moderate-to-severe dementia, n=50). Compared with the controls, plasma levels of VCAM-1 (p< 0.001), ICAM-1 (p=0.028) and E-selectin (p=0.016) were significantly higher in the patients, but only VCAM-1 levels significantly reflected the severity of dementia (p< 0.001). In addition, only VCAM-1 levels showed an association with macro- and micro- white matter changes especially in the superior longitudinal fasciculus (p< 0.001), posterior thalamic radiation (p=0.002), stria terminalis (p=0.002) and corpus callosum (p=0.009), and were independent of, age and cortical volume. These tracts show significant association with MMSE, short term memory and visuospatial function. Meanwhile, while VCAM-1 level correlated significantly with short-term memory (p=0.026) and drawing (p=0.025) scores in the AD patients after adjusting for age and education, the significance disappeared after adjusting for global FA. Endothelial activation, especially VCAM-1, was of clinical significance in AD that reflects macro- and micro-structural changes and poor short term memory and visuospatial function.