Influence of Physiological Variables and Comorbidities on Plasma Aß40, Aß42, and p-tau181 Levels in Cognitively Unimpaired Individuals.

Plasma biomarkers for Alzheimer's disease (AD) are a promising tool that may help in early diagnosis. However, their levels may be influenced by physiological parameters and comorbidities that should be considered before they can be used at the population level. For this purpose, we assessed the influences of different comorbidities on AD plasma markers in 208 cognitively unimpaired subjects. We analyzed both plasma and cerebrospinal fluid levels of Aß40, Aß42, and p-tau181 using the fully automated Lumipulse platform. The relationships between the different plasma markers and physiological variables were studied using linear regression models. The mean differences in plasma markers according to comorbidity groups were also studied. The glomerular filtration rate showed an influence on plasma Aß40 and Aß42 levels but not on the Aß42/Aß40 ratio. The amyloid ratio was significantly lower in diabetic and hypertensive subjects, and the mean p-tau181 levels were higher in hypertensive subjects. The glomerular filtration rate may have an inverse relationship on plasma Aß40 and Aß42 levels but not on the amyloid ratio, suggesting that the latter is a more stable marker to use in the general population. Cardiovascular risk factors might have a long-term effect on the amyloid ratio and plasma levels of p-tau181.

Sex hormones and the total testosterone:estradiol ratio as predictors of severe acute respiratory syndrome coronavirus 2 infection in hospitalized men.

BACKGROUND: The predictive ability of the early determination of sex steroids and the total testosterone:estradiol ratio for the risk of severe coronavirus disease 2019 or the potential existence of a biological gradient in this relationship has not been evaluated. OBJECTIVES: To assess the relationship of sex steroid levels and the total testosterone:estradiol ratio with the risk of severe acute respiratory syndrome coronavirus 2 infection in men, defined as the need for intensive care unit admission or death, and the predictive ability of each biomarker. MATERIALS AND METHODS: This was a prospective observational study. We included all consecutive adult men with severe acute respiratory syndrome coronavirus 2 infections in a single center admitted to a general hospital ward or to the intensive care unit. Sex steroids were evaluated at the centralized laboratory of our hospital. RESULTS: We recruited 98 patients, 54 (55.1%) of whom developed severe coronavirus disease in 2019. Compared to patients with nonsevere coronavirus disease 2019, patients with severe coronavirus disease 2019 had significantly lower serum levels of total testosterone (111 ± 89 vs. 191 ± 143 ng/dL; p < 0.001), dehydroepiandrosterone (1.69 ± 1.26 vs. 2.96 ± 2.64 ng/mL; p < 0.001), and dehydroepiandrosterone sulfate (91.72 ± 76.20 vs. 134.28 ± 98.261 µg/dL; p = 0.009), significantly higher levels of estradiol (64.61 ± 59.35 vs. 33.78 ± 13.78 pg/mL; p = 0.001), and significantly lower total testosterone:estradiol ratio (0.28 ± 0.31 vs. 0.70 ± 0.75; p < 0.001). The lower the serum level of androgen and the lower the total testosterone:estradiol ratio values, the higher the likelihood of developing severe coronavirus disease 2019, with the linear trend in the adjusted analyses being statistically significant for all parameters except for androstenedione (p = 0.064). In the receiver operating characteristic analysis, better predictive performance was shown by the total testosterone:estradiol ratio, with an area under the curve of 0.77 (95% confidence interval 0.68-0.87; p < 0.001). DISCUSSION AND CONCLUSION: Our results suggest that men with severe acute respiratory syndrome coronavirus 2 infection, decreased androgen levels and increased estradiol levels have a higher likelihood of developing an unfavorable outcome. The total testosterone:estradiol ratio showed the best predictive ability.

Accuracy of plasma Aß40, Aß42, and p-tau181 to detect CSF Alzheimer's pathological changes in cognitively unimpaired subjects using the Lumipulse automated platform.

BACKGROUND: The arrival of new disease-modifying treatments for Alzheimer's disease (AD) requires the identification of subjects at risk in a simple, inexpensive, and non-invasive way. With tools allowing an adequate screening, it would be possible to optimize the use of these treatments. Plasma markers of AD are very promising, but it is necessary to prove that alterations in their levels are related to alterations in gold standard markers such as cerebrospinal fluid or PET imaging. With this research, we want to evaluate the performance of plasma Aß40, Aß42, and p-tau181 to detect the pathological changes in CSF using the automated Lumipulse platform. METHODS: Both plasma and CSF Aß40, Aß42, and p-tau181 have been evaluated in a group of 208 cognitively unimpaired subjects with a 30.3% of ApoE4 carriers. We have correlated plasma and CSF values of each biomarker. Then, we have also assessed the differences in plasma marker values according to amyloid status (A - / +), AD status (considering AD + subjects to those A + plus Tau +), and ATN group defined by CSF. Finally, ROC curves have been performed, and the area under the curve has been measured using amyloid status and AD status as an outcome and different combinations of plasma markers as predictors. RESULTS: Aß42, amyloid ratio, p-tau181, and p-tau181/Aß42 ratio correlated significantly between plasma and CSF. For these markers, the levels were significantly different in the A + / - , AD + / - , and ATN groups. Amyloid ratio predicts amyloid and AD pathology in CSF with an AUC of 0.89. CONCLUSIONS: Plasma biomarkers of AD using the automated Lumipulse platform show good diagnostic performance in detecting Alzheimer's pathology in cognitively unimpaired subjects.

Dasatinib-Induced Chylothorax: A Clinical Laboratory's Perspective.

Dasatinib is a tyrosine kinase inhibitor drug used for chronic myeloid leukaemia (CML) treatment. Chylothorax has been rarely reported as a secondary effect of dasatinib occurring especially in long-term treated patients, although its pathophysiology is not yet fully understood. Laboratory analysis of the pleural effusion is crucial for chylothorax diagnosis. We report a case of a 53-year-old male patient presenting a chylothorax after 14 years of dasatinib therapy where the clinical laboratory was key in the diagnosis.

First report of natural Wolbachia infections in mosquitoes from Cuba.

Mosquitoes are extensively responsible for the transmission of pathogens. Novel strategies using Wolbachia could transform that scenario, since these bacteria manipulate mosquito reproduction, and can confer a pathogen transmission-blocking phenotype in culicids. Here, we screened the Wolbachia surface protein region by PCR in eight Cuban mosquito species. We confirmed the natural infections by sequencing and assessed the phylogenetic relationships among the Wolbachia strains detected. We identified four Wolbachia hosts: Aedes albopictus, Culex quinquefasciatus, Mansonia titillans, and Aedes mediovittatus (first report worldwide). Knowledge of Wolbachia strains and their natural hosts is essential for future operationalization of this vector control strategy in Cuba.

Insecticide Resistance Status of Aedes albopictus (Diptera: Culicidae) Populations from Cuba.

Aedes albopictus (Skuse, 1894) is one of the major vectors for arboviruses such as dengue, Zika, and chikungunya. Originally from Southeast Asia, this species has spread to Africa, Europe, and the Americas, including Cuba. This spread has been favored by its great adaptability to variable temperatures and to the resistance of its eggs to desiccation. Chemical control of mosquitoes is an essential alternative to stop arbovirus transmission, but insecticide resistance status of the Cuban Ae. albopictus populations is unknown. For this study, Ae. albopictus larvae and adults were collected from two municipalities in Havana, Cuba in 2019. Adult bioassays for deltamethrin, cypermethrin, lambda-cyhalothrin, chlorpyrifos, propoxur, and bendiocarb susceptibility were conducted according to CDC methodology. Larval bioassays for temephos susceptibility were performed following WHO protocols. Resistance profiles for α and ß-esterases, glutathione S-transferase (GST), and multifunction oxidases (MFO) pathways were constructed and analyzed. Resistance to temephos and deltamethrin was detected in Mulgoba and Plaza field populations, but resistance to lambda-cyhalothrin was only found in the Plaza colony. Plaza colony exhibited a higher expression level to all four metabolic enzymes and α-esterases and GTS were over-expressed in Mulgoba. The development of insecticide resistance in Cuban Ae. albopictus populations makes it imperative that we develop integrated control strategies to minimize the development of resistance and provide effective vector control that prevents the onset of arbovirus epidemics.

TNF Inhibitors Exert a "Hidden" Beneficial Effect in the Cardiovascular Lipoprotein Profile of RA Patients.

Purpose: A high cardiovascular risk has been described in patients with rheumatoid arthritis (RA); the effects of different biological agents have also been described in these patients. The aim of the present study is to examine the effects of tumor necrosis factor inhibitors (TNFi) in the lipoprotein profile of RA patients using a broad laboratory assessment including a large number of non-routine tests. Patients and Methods: RA patients treated with and without TNFi (70 patients in each group) were cross-sectionally compared regarding a broad spectrum of lipoprotein parameters including serum levels of total and HDL, LDL and VLDL cholesterol triglycerides, lipoprotein A (LpA), apolipoprotein A1 (Apo A), B100 (Apo B) and paroxonase. For each lipoprotein subfraction (HDL, LDL and VLDL), we assess specific concentrations of cholesterol, triglycerides, phospholipids and proteins and total mass of each one. Additionally, HDL Apo A, LDL and VLDL Apo B concentrations and number of particles of LDL and VLDL were also determined. Exploratory univariate and multivariate analyses of the different variables were performed. Results: Seventy patients in each subset were enrolled. Patients on treatment with TNFi showed a trend to be younger and to have a longer disease duration. Regarding the lipoprotein analyses, borderline significant higher levels of serum Apo A were detected and an independent association with lower HDL mass, LDL triglyceride, VLDL cholesterol, VLDL Apo B, VLDL mass, number of VLDL cholesterol molecules and number of particles of VLDL was clearly observed. Conclusion: TNFi treatment was associated with beneficial atherogenic effects at the lipoprotein level especially centered in the VLDL-related parameters consistent with a reduction of the atherogenic risk.

Characterization of Insecticide Resistance in Aedes aegypti from the Zoological Garden of Havana, Cuba.

Chemical control of Aedes aegypti continues to be an indispensable alternative to preventing dengue, Zika, and chikungunya outbreaks. The Havana Zoological Garden requires constant vigilance because its special characteristics help in the spread of the causal agents of diseases transmitted by mosquitoes, which put the health of visitors at risk. The goals of this study were to determine the level of susceptibility and insecticide resistance mechanisms in the Ae. aegypti population. Temephos susceptibility in larvae was evaluated with bioassays using the World Health Organization's methodology, and susceptibility of adult mosquitoes was determined by the impregnated bottle bioassay, recommended by the Centers for Disease Control and Prevention. Resistance mechanisms were determined with biochemical assays. Mosquito larvae from the Havana Zoo were found resistant to temephos, which was associated with the activity of the enzymes α- and ß-esterases and mixed function oxidases but not glutathione-S-transferase. Adult mosquitoes were susceptible to pyrethroid (lambda-cyhalothrin, deltamethrin, and cypermethrin), organophosphate (chlorpyrifos), and carbamate (bendiocarb). Temephos resistance detected in the mosquito population from the Havana Zoo is an alert for the Vector Control Program, which must take measures to manage their resistance, relying on the surveillance carried out by Cuba's medical entomology laboratories.

Impact of SARS-CoV-2 infection on liver disease.

Introduction: Abnormal liver biochemistry is not a rare finding in the context of SARS-CoV-2 infection, regardless of patients having pre-existing chronic disease or not. Content: This review examines the current body of knowledge on the relationship between COVID-19 and liver injury, which is frequently found in this setting. Summary: Although the pathogenesis of liver injury is not fully understood, it has been suggested to be the result of a combination of multiple factors. These include direct injury caused by the virus, immune system hyperactivation, ischemic and drug-induced injury. The prognostic valor of these alterations is also the subject of intense research. Due to their potential impact, these alterations require proper management and treatment, especially in patients with chronic liver disease or liver transplant recipients. Outlook: Some aspects associated with liver injury during COVID-19, especially in severe presentations, are not well understood. Studies assessing the clinical impact of COVID-19 on the healthy or diseased liver may help adjust treatment and immunization guidelines to the profile of the patient.

Control of occult hepatitis B virus infection.

Background: The diagnosis of hepatitis B virus (HBV) infection requires HBV DNA testing and serologic testing for detection of the surface antigen (HBsAg) and the hepatitis B core antibody (anti-HBc). There is a population of patients with occult HBV infection (OBI), which is not detected by HBsAg or HBV DNA quantification in blood, despite the presence of active replication in the liver. Scope: This document provides a definition of OBI and describes the diagnostic techniques currently used. It also addresses the detection of patients with risk factors and the need for screening for OBI in these patients. Summary: Correct diagnosis of OBI prevents HBV reactivation and transmission. Diagnosis of OBI is based on the detection of HBV DNA in patients with undetectable HBsAg in blood. Perspectives: A high number of patients with OBI may remain undiagnosed; therefore, screening for OBI in patients with factor risks is essential. For a correct diagnosis of OBI, it is necessary that new markers such as ultrasensitive HBsAg are incorporated, and a more comprehensive marker study is performed by including markers such as cccDNA.

First Record of Natural Transovarial Transmission of Dengue Virus in Aedes albopictus from Cuba.

Transovarial transmission (TOT) of dengue virus (DENV) in Aedes spp. is an important mechanism for DENV maintenance in nature and may be important in initiating outbreaks. The objective of this study was to explore the occurrence of TOT in wild Aedes albopictus populations in Cuba. Mosquito larvae were collected in Cotorro municipality, Havana, Cuba, and identified to species. Fifteen pools of Ae. albopictus each containing 30 larvae were processed for DENV detection by using conventional reverse transcription polymerase chain reaction (RT-PCR) and nested PCR. Four out of 15 pools processed were positive for DENV-3, but no other DENV serotype was detected. This is the first time TOT of DENV detected in Cuban field populations of Ae. albopictus, and this suggests that this species may be an important vector of DENV in Cuba.

Development of a Diagnostic Biosensor Method of Hypersensitivity Pneumonitis towards a Point-of-Care Biosensor.

In spite of a current increasing trend in the development of miniaturized, standalone point-of-care (PoC) biosensing platforms in the literature, the actual implementation of such systems in the field is far from being a reality although deeply needed. In the particular case of the population screenings for local or regional diseases related to specific pathogens, the diagnosis of the presence of specific antibodies could drastically modify therapies and even the organization of public policies. The aim of this work was to develop a fast, cost-effective detection method based on the manipulation of functionalized magnetic beads for an efficient diagnosis of hypersensitivity pneumonitis (HP), looking for the presence of anti-pigeon antigen antibodies (APAA) in a patient's serum. We presented a Diagnostic Biosensor Method (DBM) in detail, with validation by comparison with a traditional high-throughput platform (ELISA assay). We also demonstrated that it was compatible with a microfluidic chip that could be eventually incorporated into a PoC for easy and broad deployment using portable optical detectors. After standardization of the different reaction steps, we constructed and validated a plastic chip that could easily be scaled to high-volume manufacturing in the future. The solution proved comparable to conventional ELISA assays traditionally performed by the clinicians in their laboratory and should be compatible with other antibody detection directly from patient samples.

Measurement and clinical usefulness of bilirubin in liver disease.

Elevated plasma bilirubin levels are a frequent clinical finding. It can be secondary to alterations in any stage of its metabolism: (a) excess bilirubin production (i.e., pathologic hemolysis); (b) impaired liver uptake, with elevation of indirect bilirubin; (c) impaired conjugation, prompted by a defect in the UDP-glucuronosyltransferase; and (d) bile clearance defect, with elevation of direct bilirubin secondary to defects in clearance proteins, or inability of the bile to reach the small bowel through bile ducts. A liver lesion of any cause reduces hepatocyte cell number and may impair the uptake of indirect bilirubin from plasma and diminish direct bilirubin transport and clearance through the bile ducts. Various analytical methods are currently available for measuring bilirubin and its metabolites in serum, urine and feces. Serum bilirubin is determined by (1) diazo transfer reaction, currently, the gold-standard; (2) high-performance liquid chromatography (HPLC); (3) oxidative, enzymatic, and chemical methods; (4) direct spectrophotometry; and (5) transcutaneous methods. Although bilirubin is a well-established marker of liver function, it does not always identify a lesion in this organ. Therefore, for accurate diagnosis, alterations in bilirubin concentrations should be assessed in relation to patient anamnesis, the degree of the alteration, and the pattern of concurrent biochemical alterations.

Biochemical assessment of metabolic associated fatty liver disease.

Metabolic-associated fatty liver disease (MAFLD) is defined as fat accumulation in the liver in the presence of metabolic alterations. This disorder is generally asymptomatic and may progress to severe liver disease, which are linked to inflammation and/or fibrosis. MAFLD has a high prevalence (26%) and therefore a considerable number of patients are at high risk of having advanced liver disease. This document provides an overview of the most relevant serological markers in the characterization and diagnosis of MAFLD. An example is provided of a routine diagnostic algorithm that incorporates serological testing. A range of useful serological scores are currently available for the management of MAFLD patients, especially for the stratification of patients at risk of fibrosis. A large proportion of the population is at risk of developing severe liver disease. The integration of non-invasive serological markers in the stratification of patients at risk for liver fibrosis may contribute to improve the control and management of MAFLD patients.

Determination of the phenotypic age in residents of Mexico City: effect of accelerated ageing on lung function and structure.

INTRODUCTION: Phenotypic age better represents age-related biological dysregulation than chronological age. Recently, a multisystem-based ageing measure, which integrates chronological age and nine biomarkers, was proposed. METHODS: Phenotypic age was determined in 774 residents of Mexico City over 60 years old and without respiratory problems. We arbitrarily classified as "accelerated" ageing, those showing >4 years compared with their chronological age, and "slowed" ageing, those with <4 years compared with chronological age. Demographic risk factors were analysed with structured questionnaires. Lung structure was evaluated by high-resolution computed tomography and functional competence was analysed by forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), diffusion capacity of carbon monoxide (D LCO), and the 6-minute walk test (6MWT). RESULTS: Overall, 13% of this cohort showed accelerated ageing, which was corroborated with four independent biomarkers of ageing, 42% had normal ageing and 46% had slowed ageing. Risk factors associated with accelerated ageing were male sex (OR 4.4, 95% CI 2.4-7.9; p<0.01), diabetes mellitus (OR 9.7, 95% CI 5.5-17.2; p<0.01), and long-term sleep duration (OR 2.9 95% CI 1.34-6.35, p<0.01). Among smokers, there was a slight but significant association with the number of pack-years. Subjects with accelerated ageing showed decreased FVC (p<0.0001), FEV1 (p<0.0001), D LCO (p<0.02) and walking distance in the 6MWT (p=0.0001). Slowed-ageing subjects presented less frequently with emphysematous lesions compared with those with accelerated ageing. CONCLUSIONS: A small but significant proportion of residents of Mexico City age rapidly, which is associated with male sex, diabetes, and long-term sleep duration. They exhibit lower levels of lung function and develop emphysema more frequently.

Reversible Lesion of the Corpus Callosum in a Patient With Migraine With Aura: A Case Study.

OBJECTIVE: To describe a patient with migraine with aura (MWA) who was found to have a reversible lesion of the corpus callosum. BACKGROUND: Reversible lesions of the splenium of the corpus callosum are well-described clinical-radiographic phenomena, which have been associated with a wide array of disease states, including epilepsy, demyelinating disease, infection, and metabolic derangements. There have been few case reports in the literature to date of these lesions associated with migraine headache. DESIGN/METHODS: A case report. RESULTS: A 41 year-old female with a history of migraine with visual aura presented with headache associated with left-sided sensorimotor deficits. Routine laboratory tests were within normal limits. An electroencephlogram was also normal. Magnetic resonance imaging (MRI) of the brain with and without contrast revealed areas of restricted diffusion in the splenium and the genu of the corpus callosum. The patient's symptoms resolved after 2 days. A follow-up MRI 2 days after the onset of symptoms revealed resolution of the callosal lesions. The patient was diagnosed clinically with migraine with prolonged aura. CONCLUSION: MWA may be associated with reversible lesions of the corpus callosum.

Reversal of Resistance to the Larvicide Temephos in an Aedes aegypti (Diptera: Culicidae) Laboratory Strain From Cuba.

The objective of this investigation was to know whether the organophosphate temephos resistance developed in larvae from a laboratory strain of Aedes aegypti (Linnaeus, 1762) from Cuba could be reversed. The resistant laboratory strain of Ae. aegypti, named SAN-F6, was left without temephos selection pressure for 12 generations. The level of temephos resistance was determined using WHO bioassays and mechanisms of metabolic resistance were determined based on enzyme activity levels detected by biochemical assays. Bioassays and biochemical assays were conducted on the SAN-F6 parental strain and every three reversal generations (SANRevF3, SANRevF6, SANRevF9, and SANRevF12) without temephos selection pressure. After 19 yr of keeping the SAN-F6 strain under selection pressure with the LC90 of temephos, the resistance ratio (RR50) was 47.5×. Biochemical assays indicated that esterase and glutathione S-transferase are still responsible for temephos resistance in this strain, but not mixed-function oxidase. Experiments on resistance reversal showed that temephos susceptibility could be recovered as α esterase activity levels decreased. The SAN-F6 strain has provided an essential basis for studies of temephos resistance in Cuba. It was demonstrated that the resistance developed to the larvicide temephos in Ae. aegypti from this Cuban lab strain is a reversible phenomenon, which suggests that similar outcomes might be expected in field populations. As such, the use of temephos alternated with other larvicides recommended by WHO such as Bti or pyriproxyfen is recommended to maintain the effectiveness of temephos and to achieve more effective control of Ae. aegypti.

Opportunities for antimicrobial stewardship in patients with acute bacterial skin and skin structure infections who are unsuitable for beta-lactam antibiotics: a multicenter prospective observational study.

PURPOSE: The objective of this prospective, observational study was to describe the treatment, severity assessment and healthcare resources required for management of patients with acute bacterial skin and skin structure infections who were unsuitable for beta-lactam antibiotic treatments. METHODS: Patients were enrolled across five secondary care National Health Service hospitals. Eligible patients had a diagnosis of acute bacterial skin and skin structure infection and were considered unsuitable for beta-lactam antibiotics (e.g. confirmed/suspected methicillin-resistant Staphylococcus aureus, beta-lactam allergy). Data regarding diagnosis, severity of the infection, antibiotic treatment and patient management were collected. RESULTS: 145 patients with acute bacterial skin and skin structure infection were included; 79% (n = 115) patients received greater than two antibiotic regimens; median length of the first antibiotic regimen was 2 days (interquartile range of 1-5); median time to switch from intravenous to oral antibiotics was 4 days (interquartile range of 3-8, n = 72/107); 25% (n = 10/40) patients with Eron class 1 infection had systemic inflammatory response syndrome, suggesting they were misclassified. A higher proportion of patients with systemic inflammatory response syndrome received treatment in an inpatient setting, and their length of stay was prolonged in comparison with patients without systemic inflammatory response syndrome. CONCLUSION: There exists an urgent need for more focused antimicrobial stewardship strategies and tools for standardised clinical assessment of acute bacterial skin and skin structure infection severity in patients who are unsuitable for beta-lactam antibiotics. This will lead to optimised antimicrobial treatment strategies and ensure effective healthcare resource utilisation.

Preliminary Experience on Laser Interstitial Thermal Ablation Therapy in the Treatment of Extra-axial Masses: Indications, Imaging Characterization and Outcomes.

Laser thermal ablation is a novel minimally invasive neurosurgical technique that has proven to be beneficial in the treatment of a select group of neurosurgical conditions such as primary brain neoplasms, brain metastases, radiation necrosis, and epileptogenic lesions such as cortical dysplasia and mesial temporal sclerosis. The applicability of laser thermal ablation and its utility in the treatment of extra-axial (EA) brain neoplasms, mainly meningioma, is another novel use of this technique. Our article discusses the use and benefits of this technique in this particular clinical scenario. We describe our experience in a group of symptomatic patients from our institution with EA masses, mainly recurrent meningiomas, that failed previous more conventional treatment therapies such as surgery and radiotherapy. Our paper emphasizes patient selection, indications for the procedure, and post-treatment imaging characteristics of the ablated lesions.

Visual Deficit From Laser Interstitial Thermal Therapy for Temporal Lobe Epilepsy: Anatomical Considerations.

BACKGROUND: Laser interstitial thermal therapy (LITT) is quickly emerging as an effective surgical therapy for temporal lobe epilepsy (TLE). One of the most frequent complications of the procedure is postoperative visual field cuts, but the physiopathology of these deficits is unknown. OBJECTIVE: To evaluate potential causes of visual deficits after LITT for TLE in an attempt to minimize this complication. METHODS: This retrospective chart review compares the case of a 24-year-old male who developed homonymous hemianopsia following LITT for TLE to 17 prior patients who underwent the procedure and suffered no visual deficit. We examined both features of the surgical approach (trajectory, laser energy, ablation size) and of preoperative surgical anatomy, derived from volumetric tracings of mesiotemporal structures. RESULTS: For the patient with postoperative homonymous hemianopsia imaging suggested inadvertent ablation of the lateral geniculate nucleus, although the laser was positioned entirely within the hippocampus. This patient's laser trajectory, ablation number, energy delivered, and ablation size were not significantly different from the prior patients. However, the subject with the visual deficit did have significantly smaller choroidal fissure cerebrospinal fluid volume. CONCLUSION: Visual deficits are the most common complication of LITT for mesiotemporal epilepsy and patients at most risk may have small cerebrospinal fluid volume in the choroidal fissure, allowing heat to spread from the hippocampal body to the lateral geniculate nucleus. When such anatomy is identified on preoperative magnetic resonance imaging, we recommend lowering laser trajectory, decreasing ablation power through the hippocampal body, and using temperature safety markers at the lower thalamic border.