Endoscopic endonasal obliteration of the frontal recess and anterior skull base.

BACKGROUND: Although endoscopic techniques have become more widespread in repair of frontal sinus (FS) defects, certain pathologies still require open approach (extensive trauma or tumors). Under certain circumstances even multiple complex open reconstructive procedures might fail to resolve persistent pneumocephalus or CSF leak and subsequently surgeons tend to escalate the invasiveness and employ even more complex and aggressive approaches. We present our experience treating persistent pneumocephalus or CSF leak after previously failed transcranial reconstruction utilizing an endoscopic endonasal approach (EEA). METHODS: We retrospectively reviewed a prospectively maintained database of all patients undergoing an EEA for repair of persistent pneumocephalus or CSF leak following FS cranialization between 2016 and 2020. RESULTS: Six patients who underwent cranialization of the FS with subsequent persistent pneumocephalus or CSF leak were identified; two patients suffered a traumatic fracture of the FS, remaining four patients had undergone previous cranial surgery. Clear violation of the FS was not recognized in one patient. All patients underwent cranialization of the FS either directly following initial craniotomy or during open repair of a FS fracture. Two patients underwent multiple transcranial surgeries including using vascularized free tissue transfer. Complete cessation of pneumocephalus/CSF leak was achieved in 83.3% (5/6) after the first and 100% (6/6) after two endoscopic procedures. No morbidity or mortality resulted from the endoscopic procedure. CONCLUSIONS: Skull base defects following a failed cranialization of FS are usually located in or in close proximity to the frontal recess. These defects can be safely and effectively repaired via an EEA.

No change in network connectivity measurements between separate rsfMRI acquisition times.

The role of resting state functional MRI (rsfMRI) is increasing in the field of epilepsy surgery because it is possible to interpolate network connectivity patterns across the brain with a high degree of spatial resolution. Prior studies have shown that by rsfMRI with scalp electroencephalography (EEG), an epileptogenic network can be modeled and visualized with characteristic patterns of connectivity that are relevant to both seizure-related and neuropsychological outcomes after surgery. The aim of this study is to show that a 5-min acquisition time provides reproducible results related to the relevant connectivity metrics when compared to a separately acquired 5-min scan. Fourteen separate rsfMRI sessions from ten different patients were used for comparison, comprised of patients with temporal lobe epilepsy both pre- and post-operation. Results showed that there was no significant difference in any of the connectivity metrics when comparing both 5-min scans to each other. These data support the continued use of a 5-min scan for epileptogenic network modeling in future studies because the inter-scan variability is sufficiently low as not to alter the output metrics characterizing the network connectivity.

Revision and removal of vagus nerve stimulation systems: twenty-five years' experience.

BACKGROUND: Epilepsy, a disease characterized by recurrent seizures, is a common chronic neurologic condition. Antiepileptic drugs (AED) are the mainstay of treatment for epilepsy. Vagus nerve stimulation (VNS) surgery is an adjuvant therapy for the treatment of drug refractory epilepsy (DRE). VNS revision and implant removal surgeries remain common. METHODS: Using a single neurosurgeon data registry for epilepsy surgery, we retrospectively analyzed a total of 824 VNS surgeries. Patients were referred to two Level IV Comprehensive Epilepsy centers (from 08/1997 to 08/2022) for evaluation. Patients were divided into four groups: new device placement, revision surgery, removal surgery, and battery replacement for end-of-life of the generator. The primary endpoint was to analyze the reasons that led patients to undergo revision and removal surgeries. The time period from the index surgery to the removal surgery was also calculated. RESULTS: The median age of patients undergoing any type of surgery was 34 years. The primary reason for revision surgeries was device malfunction, followed by patients' cosmetic dissatisfaction. There was no statistical sex-difference in revision surgeries. The median age and body mass index (BMI) of patients who underwent revision surgery were 38 years and 26, respectively. On the other hand, the primary reason for removal was lack of efficacy, followed again by cosmetic dissatisfaction. The survival analysis showed that 43% of VNS device remained in place for 5 years and 50% of the VNS devices were kept for 1533 days or 4.2 years. CONCLUSIONS: VNS therapy is safe and well-tolerated. VNS revision and removal surgeries occur in less than 5% of cases. More importantly, attention to detail and good surgical technique at the time of the index surgery can increase patient satisfaction, minimize the need for further surgeries, and improve acceptance of the VNS technology.

Long-term outcomes of mesial temporal laser interstitial thermal therapy for drug-resistant epilepsy and subsequent surgery for seizure recurrence: a multi-centre cohort study.

BACKGROUND: Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive alternative to surgical resection for drug-resistant mesial temporal lobe epilepsy (mTLE). Reported rates of seizure freedom are variable and long-term durability is largely unproven. Anterior temporal lobectomy (ATL) remains an option for patients with MRgLITT treatment failure. However, the safety and efficacy of this staged strategy is unknown. METHODS: This multicentre, retrospective cohort study included 268 patients consecutively treated with mesial temporal MRgLITT at 11 centres between 2012 and 2018. Seizure outcomes and complications of MRgLITT and any subsequent surgery are reported. Predictive value of preoperative variables for seizure outcome was assessed. RESULTS: Engel I seizure freedom was achieved in 55.8% (149/267) at 1 year, 52.5% (126/240) at 2 years and 49.3% (132/268) at the last follow-up ≥1 year (median 47 months). Engel I or II outcomes were achieved in 74.2% (198/267) at 1 year, 75.0% (180/240) at 2 years and 66.0% (177/268) at the last follow-up. Preoperative focal to bilateral tonic-clonic seizures were independently associated with seizure recurrence. Among patients with seizure recurrence, 14/21 (66.7%) became seizure-free after subsequent ATL and 5/10 (50%) after repeat MRgLITT at last follow-up≥1 year. CONCLUSIONS: MRgLITT is a viable treatment with durable outcomes for patients with drug-resistant mTLE evaluated at a comprehensive epilepsy centre. Although seizure freedom rates were lower than reported with ATL, this series represents the early experience of each centre and a heterogeneous cohort. ATL remains a safe and effective treatment for well-selected patients who fail MRgLITT.

Autoantibodies targeting G protein-coupled receptors: An evolving history in autoimmunity. Report of the 4th international symposium.

G protein-coupled receptors (GPCR) are involved in various physiological and pathophysiological processes. Functional autoantibodies targeting GPCRs have been associated with multiple disease manifestations in this context. Here we summarize and discuss the relevant findings and concepts presented in the biennial International Meeting on autoantibodies targeting GPCRs (the 4th Symposium), held in Lübeck, Germany, 15-16 September 2022. The symposium focused on the current knowledge of these autoantibodies' role in various diseases, such as cardiovascular, renal, infectious (COVID-19), and autoimmune diseases (e.g., systemic sclerosis and systemic lupus erythematosus). Beyond their association with disease phenotypes, intense research related to the mechanistic action of these autoantibodies on immune regulation and pathogenesis has been developed, underscoring the role of autoantibodies targeting GPCRs on disease outcomes and etiopathogenesis. The observation repeatedly highlighted that autoantibodies targeting GPCRs could also be present in healthy individuals, suggesting that anti-GPCR autoantibodies play a physiologic role in modeling the course of diseases. Since numerous therapies targeting GPCRs have been developed, including small molecules and monoclonal antibodies designed for treating cancer, infections, metabolic disorders, or inflammatory conditions, anti-GPCR autoantibodies themselves can serve as therapeutic targets to reduce patients' morbidity and mortality, representing a new area for the development of novel therapeutic interventions.

Altered endocannabinoid metabolism compromises the brain-CSF barrier and exacerbates chronic deficits after traumatic brain injury in mice.

Endocannabinoids [2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA)], endogenously produced arachidonate-based lipids, are anti-inflammatory physiological ligands for two known cannabinoid receptors, CB1 and CB2, yet the molecular and cellular mechanisms underlying their effects after brain injury are poorly defined. In the present study, we hypothesize that traumatic brain injury (TBI)-induced loss of endocannabinoids exaggerates neurovascular injury, compromises brain-cerebrospinal fluid (CSF) barriers (BCB) and causes behavioral dysfunction. Preliminary analysis in human CSF and plasma indicates changes in endocannabinoid levels. This encouraged us to investigate the levels of endocannabinoid-metabolizing enzymes in a mouse model of controlled cortical impact (CCI). Reductions in endocannabinoid (2-AG and AEA) levels in plasma were supported by higher expression of their respective metabolizing enzymes, monoacylglycerol lipase (MAGL), fatty acid amide hydrolase (FAAH), and cyclooxygenase 2 (Cox-2) in the post-TBI mouse brain. Following increased metabolism of endocannabinoids post-TBI, we observed increased expression of CB2, non-cannabinoid receptor Transient receptor potential vanilloid-1 (TRPV1), aquaporin 4 (AQP4), ionized calcium binding adaptor molecule 1 (IBA1), glial fibrillary acidic protein (GFAP), and acute reduction in cerebral blood flow (CBF). The BCB and pericontusional cortex showed altered endocannabinoid expressions and reduction in ventricular volume. Finally, loss of motor functions and induced anxiety behaviors were observed in these TBI mice. Taken together, our findings suggest endocannabinoids and their metabolizing enzymes play an important role in the brain and BCB integrity and highlight the need for more extensive studies on these mechanisms.

Protocol for behavioral and neural recording during stimulation of the macaque monkey nucleus basalis.

We present an experimental protocol to record neuronal activity during intermittent stimulation of nucleus basalis (NB), as macaque monkeys perform cognitive tasks. This protocol includes implantation of electrodes and generator devices to deliver electrical stimulation to NB using multiple approaches in monkeys. Direct stimulation of NB avoids peripheral cholinergic side effects, optimizes timing, and activates non-cholinergic projection neurons. We describe electrode preparation, surgery, and implantation for direct evaluation of how stimulation affects monkeys' behavior and neuronal activity. For complete details on the use and execution of this profile, please refer to Qi et al. (2021).

Tethered brain: disentangling unintentional brain-mesh interfaces. Illustrative case.

BACKGROUND: Surgical meshes have found widespread use in neurosurgical practice. While commonly recognized risks of synthetic mesh include infection, exposure of mesh implants, and foreign body reaction, the risk of mesh tethering to neural structures is often overlooked. OBSERVATIONS: The authors presented the first case, to their knowledge, of the disentanglement of mesh interfaced to cortical tissue. The patient, a 68-year-old woman, presented with severe intractable seizure disorder and worsening left hand function and incoordination after meningioma resection and cranioplasty 9 years earlier. Magnetic resonance imaging (MRI) demonstrated interval progression of macrocystic encephalomalacia involving the right supplementary motor area, with fluid-attenuated inversion recovery signal extending posteriorly into the right primary motor cortex. Both computed tomography and MRI suggested potential tethering of the cortex to the overlying cranioplasty mesh. Because of the progressive nature of her condition, the decision was made to surgically remove the tethered mesh. LESSONS: De-tethering brain parenchyma from surgical mesh requires careful microdissection and judicious use of electrocautery to minimize further tissue damage and preserve neurological function. This inadvertent complication evinces the importance of using dural substitutes when unable to primarily repair the dura to prevent scarring and tethering of neural tissues to synthetic cranioplasty materials.

Concomitant central venous sinus thrombosis and subdural hematoma in acute promyelocytic leukemia: middle meningeal artery embolization enables safe anticoagulation. Illustrative case.

BACKGROUND: Acute promyelocytic leukemia (APL) has long been associated with coagulation disorders. The proposed mechanism is a combination of fibrinolysis, proteolysis, platelet dysfunction, thrombocytopenia, and possibly disseminated intravascular coagulation. Hemorrhagic complications are prominent. OBSERVATIONS: In this case, a 25-year-old female with newly diagnosed APL developed extensive cerebral venous thrombosis (CVT) and was initiated on a protocol with idarubicin and all-trans retinoic acid. The general recommendation for treating CVT is anticoagulation to stabilize the existing thrombus and prevent propagation. The patient was initiated on a heparin drip, but her clinical course was complicated by subdural hemorrhage (SDH) and epidural hemorrhage in the setting of thrombocytopenia. Anticoagulation was held, and her CVT propagated on follow-up imaging. To restart anticoagulation for CVT with a limited risk of SDH, the authors pursued middle meningeal artery (MMA) embolization. The patient was transitioned to apixaban and discharged to home. LESSONS: MMA embolization enables safe anticoagulation in patients with concomitant CVT and SDH. The authors report the complex clinical course and effective management of this rare clinical scenario.

Anatomic Study Quantifying the Relationship Between the Arcuate Eminence and the Root of the Zygoma: Application to Skull Base Surgery.

OBJECTIVE: The aim of this study was to define the structural relationship between the arcuate eminence (AE) and a known fixed external bony landmark, the root of the zygoma (ZR), and to determine its reliability as a consistent guide for guiding surgical approaches. To our knowledge, this is the only anatomic study to quantify the relationship between the AE and ZR. METHODS: Twenty-one dry temporal bones were measured using digital calipers. The distance from the posterior aspect of the ZR to the midpoint of the AE was measured. Additionally, the anteroposterior distance between the ZR and AE and vertical distance between the 2 structures were measured. Student's t-test was used to compare the left and right sides. RESULTS: An AE was found in every specimen. The mean ZR to AE distance was 30.9 mm. On most sides (91%), the ZR was located more inferiorly than the AE with a mean distance of 3 mm between the 2 structures. The mean distance between the AE and ZR was 17 mm. On all sides, the AE was located posterior to the ZR. No significant differences were found between sides. No anatomic variations or pathologic conditions were noted in any of the specimens. CONCLUSIONS: The ZR is an easily identifiable and consistent bony landmark often used by skull base surgeons. In this investigation, we measured the anatomic relationships between the ZR and AE. Such data might assist in planning surgical trajectories and minimizing complications when skull base pathologies are approached.

Targeting the endocannabinoid system: a predictive, preventive, and personalized medicine-directed approach to the management of brain pathologies.

Cannabis-inspired medical products are garnering increasing attention from the scientific community, general public, and health policy makers. A plethora of scientific literature demonstrates intricate engagement of the endocannabinoid system with human immunology, psychology, developmental processes, neuronal plasticity, signal transduction, and metabolic regulation. Despite the therapeutic potential, the adverse psychoactive effects and historical stigma, cannabinoids have limited widespread clinical application. Therefore, it is plausible to weigh carefully the beneficial effects of cannabinoids against the potential adverse impacts for every individual. This is where the concept of "personalized medicine" as a promising approach for disease prediction and prevention may take into the account. The goal of this review is to provide an outline of the endocannabinoid system, including endocannabinoid metabolizing pathways, and will progress to a more in-depth discussion of the therapeutic interventions by endocannabinoids in various neurological disorders.

Surgical disconnection of epilepsy network correlates with improved outcomes.

PURPOSE: A novel software algorithm combining non-invasive EEG and resting state functional MRI data to map networks of cortex correlated to epileptogenic tissue was used to map an epilepsy network non-invasively. The relationship between epilepsy network connectivity and outcomes after surgery was investigated using this non-invasive and non-concurrent modeling algorithm. METHOD: Scalp EEG and resting state functional MRI were acquired for nineteen patients with temporal lobe epilepsy. The hypothetical irritative zone was mapped, and resting state functional MRI data was used to model regions functionally correlated with the irritative zone. Epilepsy network connectivity was measured in patient with temporal lobe epilepsy (n = 19) both pre- and post-operatively. Temporal networks were also mapped in healthy control participants (n = 6). RESULTS: Thirteen of nineteen patients (68 %) were seizure free after 20.3 ± 4.8 months. Epilepsy network connectivity within the temporal lobe was significantly higher among patients with temporal lobe epilepsy compared to the healthy control patients (p < 0.05). Disconnection of the epilepsy network was significantly higher in patients who were seizure free. Using spearman rho analyses, neuropsychological function after surgery was found to be relatively better in patients with higher degree of epilepsy network disconnection. CONCLUSIONS: The magnitude of network disconnection after surgery was strongly associated with increased rates of seizure freedom and relatively better neuropsychological measures of memory and naming function. It was shown that seizure-free outcomes and relatively improved neuropsychological function correlated with surgical disconnection of a highly synchronous epilepsy network.

Surgery of the amygdala and uncus: a case series of glioneuronal tumors.

BACKGROUND: Patients with a lesion within the amygdala and uncus may develop temporal lobe epilepsy despite having functional mesial structures. Resection of functional hippocampus and surrounding structures may lead to unacceptable iatrogenic deficits. To our knowledge, there is limited descriptions of surgical techniques for selectively resecting the amygdala and uncus lesions while preserving the hippocampus in patients with language-dominant temporal lobe pathology. METHODS: Thirteen patients with language-dominant temporal lobe epilepsy related to amygdala-centric lesions were identified. Patients with sclerosis of the mesial structures or evidence of pathology outside of the amygdala-uncus region were excluded. Neuropsychological evaluation confirmed normal function of the mesial structures ipsilateral to the lesion. All patients were worked up with video-EEG, high-resolution brain MRI, neuro-psychology evaluation, and either Wada or functional MRI testing. RESULTS: All patients underwent selective resection of the lesion including amygdala and uncus with preservation of the hippocampus via a transcortical inferior temporal gyrus approach to the mesial temporal lobe. Pathology was compatible with glioneuronal tumors. Post-operative MRI demonstrated complete resection in all patients. Eight of the thirteen patients underwent post-operative neuropsychology evaluations and did not demonstrate any significant decline in tasks of delayed verbal recall or visual memory based on the Rey Auditory Verbal Learning Test (RAVLT). One patient showed a slight decrease in confrontation naming using the Boston Naming Test (BNT). Seizure freedom (Engel class I) was achieved in 12 of 13 patients. CONCLUSION: Selective transcortical amygdala and uncus resection with hippocampus preservation may be a reasonable way to achieve seizure control while sparing functional mesial structures.

Seizure Freedom After Epilepsy Surgery and Higher Baseline Cognition May Be Associated With a Negatively Correlated Epilepsy Network in Temporal Lobe Epilepsy.

Background: Brain regions positively correlated with the epileptogenic zone in patients with temporal lobe epilepsy vary in spread across the brain and in the degree of correlation to the temporal lobes, thalamus, and limbic structures, and these parameters have been associated with pre-operative cognitive impairment and seizure freedom after epilepsy surgery, but negatively correlated regions have not been as well studied. We hypothesize that connectivity within a negatively correlated epilepsy network may predict which patients with temporal lobe epilepsy will respond best to surgery. Methods: Scalp EEG and resting state functional MRI (rsfMRI) were collected from 19 patients with temporal lobe epilepsy and used to estimate the irritative zone. Using patients' rsfMRI, the negatively correlated epilepsy network was mapped by determining all the brain voxels that were negatively correlated with the voxels in the epileptogenic zone and the spread and average connectivity within the network was determined. Results: Pre-operatively, connectivity within the negatively correlated network was inversely related to the spread (diffuseness) of that network and positively associated with higher baseline verbal and logical memory. Pre-operative connectivity within the negatively correlated network was also significantly higher in patients who would go on to be seizure free. Conclusion: Patients with higher connectivity within brain regions negatively correlated with the epilepsy network had higher baseline memory function, narrower network spread, and were more likely to be seizure free after surgery.

Network connectivity separate from the hypothesized irritative zone correlates with impaired cognition and higher rates of seizure recurrence.

INTRODUCTION: Surgery remains an essential option for the treatment of medically intractable temporal lobe epilepsy (TLE). However, only 66% of patients achieve postoperative seizure freedom, perhaps attributable to an incomplete understanding of brain network alterations in surgical candidates. Here, we applied a novel network modeling algorithm and measured key characteristics of epileptic networks correlated with surgical outcomes and objective measures of cognition. METHODS: Twenty-two patients were prospectively included, and relevant demographic information was attained. Resting state functional magnetic resonance imaging (rsfMRI) and electroencephalography (EEG) data were recorded and preprocessed. Using our novel algorithm, patient-specific epileptic networks were mapped preoperatively, and geographic spread was quantified. Global functional connectivity was also determined using a volumetric functional atlas. Neuropsychological pre- and postsurgical raw and standardized scores obtained blinded to epileptic network status. Key demographic data and features of epileptic networks were then correlated with surgical outcome using Pearson's product-moment correlation. RESULTS: At an average follow-up of 18.4 months, 15/22 (68%) patients were seizure-free. Connectivity was measured globally using a functional 3D atlas. Higher mean global connectivity correlated with worse scores in preoperative neuropsychological testing of executive functioning (Ruff Figural Fluency Test [RFFT]-ER; R = 0.943, p = 0.005). A higher ratio of highly correlated connections between regions of interest (ROIs) in the hemisphere contralateral to the seizure onset correlated with impairment in executive functioning (RFFT-ER; R = 0.943, p = 0.005). Higher numbers of highly correlated connections between ROIs in the contralateral hemisphere correlated with impairment in both short- and long-term measures of verbal memory (Rey Auditory Verbal Learning Test Trials 6, 7 [RAVLT6, RAVLT7]; R = -0.650, p = 0.020, R = -0.676, p = 0.030). Epilepsy networks were modeled in each patient, and localization of the epilepsy network in the bitemporal lobes correlated with lower scores in neuropsychological tests measuring verbal learning and short-term memory (RAVLT6; R = -0.671, p = 0.024). Higher rates of seizure recurrence correlated with localization of the epilepsy network bitemporally (R = -0.542, p = 0.014), with the stronger correlation found with localization to the contralateral temporal lobe from side of surgery (R = - 0.530, p = 0.016). CONCLUSION: Increased connectivity contralateral to seizure onset and epilepsy network spread in the bitemporal lobes correlated with lower measures of executive functioning and verbal memory. Epilepsy network localization to the bitemporal lobes, in particular, the contralateral temporal lobe, is associated with higher rates of seizure recurrence. These findings may reflect network-level disruption that has infiltrated the contralateral hemisphere and the bitemporal lobes contributing to impaired cognition and relatively worse surgical outcomes. Further identification of network parameters that predict patient outcomes may aid in patient selection, resection planning, and ultimately the efficacy of epilepsy surgery.

Effects of surgical targeting in laser interstitial thermal therapy for mesial temporal lobe epilepsy: A multicenter study of 234 patients.

OBJECTIVE: Laser interstitial thermal therapy (LITT) for mesial temporal lobe epilepsy (mTLE) has reported seizure freedom rates between 36% and 78% with at least 1 year of follow-up. Unfortunately, the lack of robust methods capable of incorporating the inherent variability of patient anatomy, the variability of the ablated volumes, and clinical outcomes have limited three-dimensional quantitative analysis of surgical targeting and its impact on seizure outcomes. We therefore aimed to leverage a novel image-based methodology for normalizing surgical therapies across a large multicenter cohort to quantify the effects of surgical targeting on seizure outcomes in LITT for mTLE. METHODS: This multicenter, retrospective cohort study included 234 patients from 11 centers who underwent LITT for mTLE. To investigate therapy location, all ablation cavities were manually traced on postoperative magnetic resonance imaging (MRI), which were subsequently nonlinearly normalized to a common atlas space. The association of clinical variables and ablation location to seizure outcome was calculated using multivariate regression and Bayesian models, respectively. RESULTS: Ablations including more anterior, medial, and inferior temporal lobe structures, which involved greater amygdalar volume, were more likely to be associated with Engel class I outcomes. At both 1 and 2 years after LITT, 58.0% achieved Engel I outcomes. A history of bilateral tonic-clonic seizures decreased chances of Engel I outcome. Radiographic hippocampal sclerosis was not associated with seizure outcome. SIGNIFICANCE: LITT is a viable treatment for mTLE in patients who have been properly evaluated at a comprehensive epilepsy center. Consideration of surgical factors is imperative to the complete assessment of LITT. Based on our model, ablations must prioritize the amygdala and also include the hippocampal head, parahippocampal gyrus, and rhinal cortices to maximize chances of seizure freedom. Extending the ablation posteriorly has diminishing returns. Further work is necessary to refine this analysis and define the minimal zone of ablation necessary for seizure control.

ENDOCRINE OUTCOMES OF TRANSSPHENOIDAL SURGERY FOR PITUITARY APOPLEXY VERSUS ELECTIVE SURGERY FOR PITUITARY ADENOMA.

Objective: To determine the rate of hormone replacement therapy (HRT) after transsphenoidal surgery (TSS) for pituitary apoplexy (PA) versus elective resection of a null cell (NC) macroadenoma. Methods: A retrospective cohort study was performed. Data was collected on all consecutive patients who underwent TSS from December 31, 2000 to December 31, 2016. Patients were split into two groups: (1) patients that presented with PA, and (2) patients that underwent elective TSS for NC macroadenoma. Postoperative pituitary function was determined by examining HRT, hormone lab values, and an evaluation by an endocrinologist for each patient. The odds ratio (OR) was calculated to determine if there was an association between PA and the need for HRT after surgery when compared to elective resection of a NC macroadenoma. Results: The need for HRT was significantly higher following surgery for PA compared to resection of a NC macroadenoma (14.7% versus 2.9%, OR = 5.690; 95% confidence interval (CI) = 1.439 to 22.500; P = .013). Conclusion: There is an increased need for hormone replacement therapy after surgery in patients with PA versus patients undergoing elective resection of a NC macroadenoma. Further studies are warranted to strengthen this data and help determine further predictors of the need for HRT. Abbreviations: BNP = brain natriuretic peptide; CI = confidence interval; DDAVP = desmopressin acetate; GH = growth hormone; HRT = hormone replacement therapy; MRI = magnetic resonance imaging; NC = null cell (adenoma); OR = odds ratio; PA = pituitary apoplexy; TSS = transsphenoidal surgery.

Clinically Significant Visual Deficits after Laser Interstitial Thermal Therapy for Mesiotemporal Epilepsy.

BACKGROUND: Laser interstitial thermal therapy (LITT) has recently gained popularity as a minimally invasive surgical option for the treatment of mesiotemporal epilepsy (mTLE). Similar to traditional open procedures for epilepsy, the most frequent neurological complications of LITT are visual deficits; however, a critical analysis of these injuries is lacking. OBJECTIVES: To evaluate the visual deficits that occur after LITT for mTLE and their etiology. METHOD: We surveyed five academic epilepsy centers that regularly perform LITT for cases of self-reported postoperative visual deficits. For these patients all pre-, intra- and postoperative MRIs were co-registered with an anatomic atlas derived from 7T MRI data. This was used to estimate thermal injury to early visual pathways and measure imaging variables relevant to the LITT procedure. Using logistic regression, we then compared 14 variables derived from demographics, mesiotemporal anatomy, and the surgical procedure for the patients with visual deficits to a normal cohort comprised of the first 30 patients to undergo this procedure at a single institution. RESULTS: Of 90 patients that underwent LITT for mTLE, 6 (6.7%) reported a postoperative visual deficit. These included 2 homonymous hemianopsias (HHs), 2 quadrantanopsias, and 2 cranial nerve (CN) IV palsies. These deficits localized to the posterior aspect of the ablation, corresponding to the hippocampal body and tail, and tended to have greater laser energy delivered in that region than the normal cohort. The patients with HH had insult localized to the lateral geniculate nucleus, which was -associated with young age and low choroidal fissure CSF volume. Quadrantanopsia, likely from injury to the optic radiation in Meyer's loop, was correlated with a lateral trajectory and excessive energy delivered at the tail end of the ablation. Patients with CN IV injury had extension of contrast to the tentorial edge associated with a mesial laser trajectory. CONCLUSIONS: LITT for epilepsy may be complicated by various classes of visual deficit, each with distinct etiology and clinical significance. It is our hope that by better understanding these injuries and their mechanisms we can eventually reduce their occurrence by identifying at-risk patients and trajectories and appropriately tailoring the ablation procedure.