Wharen, Robert E.

AbstractGeniculate neuralgia (GN) is an uncommon, but severe, condition that is characterized by excruciating paroxysmal pain in the seventh cranial nerve's cutaneous distribution of general somatic afferent fibers carried through the nervus intermedius (NI). GN becomes a surgical disease in refractory cases of pain after exhaustive medical management. Surgical intervention in the form of microvascular decompression and nerve sectioning has been investigated with good patient outcomes. Despite this, there are limited guidelines on either technique's appropriateness in specific operative scenarios. In our 30‐year experience in GNs surgical management, we have found that a detailed knowledge of the NIs anatomy, variants, and intraoperative surgical anatomic findings are the key to choosing the most appropriate intervention, and may provide the answer to why some patients fail to experience pain relief after surgery. These anatomic variants also may explain why many patients commonly do not experience side effects related to the visceral efferent and special afferent fibers after nerve sectioning.

Spinal epidural abscess caused by MRSA, a life-threatening organism resistant to methicillin and other antibiotics, is a rare but important infectious pathology due to its potential damage to the spinal cord. We present the case of a 74-year-old man who hematogenously seeded his entire epidural spinal canal from C1 to sacrum with MRSA bacteria and remained infected even after maximal treatment with vancomycin and daptomycin. Ceftaroline, a new 5th generation antibiotic with recently described clearance of widespread MRSA infection in epidural complex spine infections, was added to vancomycin as dual therapy for his MRSA infection. A 74-year-old diabetic man with prior right total knee arthroplasty and MRSA infection presented with persistent bacteremia and sepsis. He was transferred to our academic center after diagnosis of entire spine epidural abscesses from C1 to sacral levels with midthoracic MRI T2 hyperintensities of the vertebral bodies and disc concerning for osteomyelitis and discitis. Despite surgery and IV vancomycin with MIC of 1, suggesting extreme susceptibility, the patient’s blood cultures remained persistently bacteremic at day 5 of treatment. After 48 hours of dual antibiotic therapy with vancomycin and ceftaroline, his blood cultures came back showing no growth. The patient’s outcome was unfavorable due to the advanced nature of his infection and multiple comorbidities, but his negative blood cultures after the addition of ceftaroline to his regime require further investigation into this dual therapy. Randomized controlled trials of 5th generation or combinatorial antibiotics should be considered for this disease.

OBJECTIVE Although it is still early in its application, laser interstitial thermal therapy (LiTT) has increasingly been employed as a surgical option for patients with mesial temporal lobe epilepsy. This study aimed to describe mesial temporal lobe ablation volumes and seizure outcomes following LiTT across the Mayo Clinic’s 3 epilepsy surgery centers. METHODS This was a multi-site, single-institution, retrospective review of seizure outcomes and ablation volumes following LiTT for medically intractable mesial temporal lobe epilepsy between October 2011 and October 2015. Pre-ablation and post-ablation follow-up volumes of the hippocampus were measured using FreeSurfer, and the volume of ablated tissue was also measured on intraoperative MRI using a supervised spline-based edge detection algorithm. To determine seizure outcomes, results were compared between those patients who were seizure free and those who continued to experience seizures. RESULTS There were 23 patients who underwent mesial temporal LiTT within the study period. Fifteen patients (65%) had left-sided procedures. The median follow-up was 34 months (range 12–70 months). The mean ablation volume was 6888 mm 3 . Median hippocampal ablation was 65%, with a median amygdala ablation of 43%. At last follow-up, 11 (48%) of these patients were seizure free. There was no correlation between ablation volume and seizure freedom (p = 0.69). There was also no correlation between percent ablation of the amygdala (p = 0.28) or hippocampus (p = 0.82) and seizure outcomes. Twelve patients underwent formal testing with computational visual fields. Visual field changes were seen in 67% of patients who underwent testing. Comparing the 5 patients with clinically noticeable visual field deficits to the rest of the cohort showed no significant difference in ablation volume between those patients with visual field deficits and those without (p = 0.94). There were 11 patients with follow-up neuropsychological testing. Within this group, verbal learning retention was 76% in the patients with left-sided procedures and 89% in those with right-sided procedures. CONCLUSIONS In this study, there was no significant correlation between the ablation volume after LiTT and seizure outcomes. Visual field deficits were common in formally tested patients, much as in patients treated with open temporal lobectomy. Further studies are required to determine the role of amygdalohippocampal ablation.

AbstractIntroductionSince the introduction of wearable head‐up displays, there has been much interest in the surgical community adapting this technology into routine surgical practice.MethodsWe used the keywords augmented reality OR wearable device OR head‐up display AND surgery using PubMed, EBSCO, IEEE and SCOPUS databases. After exclusions, 74 published articles that evaluated the utility of wearable head‐up displays in surgical settings were included in our review.ResultsAcross all studies, the most common use of head‐up displays was in cases of live streaming from surgical microscopes, navigation, monitoring of vital signs, and display of preoperative images. The most commonly used head‐up display was Google Glass. Head‐up displays enhanced surgeons' operating experience; common disadvantages include limited battery life, display size and discomfort.ConclusionsDue to ergonomic issues with dual‐screen devices, augmented reality devices with the capacity to overlay images onto the surgical field will be key features of next‐generation surgical head‐up displays.

AbstractBackgroundWearable technology is growing in popularity as a result of its ability to interface with normal human movement and function.MethodsUsing proprietary hardware and software, neuronavigation images were captured and transferred wirelessly via a password‐encrypted network to the head‐up display. The operating surgeon wore a loupe‐mounted wearable head‐up display during image‐guided parieto‐occipital ventriculoperitoneal shunt placement in two patients.ResultsThe shunt placement was completed successfully without complications. The tip of the catheter ended well within the ventricles away from the ventricular wall. The wearable device allowed for continuous monitoring of neuronavigation images in the right upper corner of the surgeon's visual field without the need for the surgeon to turn his head to view the monitors.ConclusionsThe adaptable nature of this proposed system permits the display of video data to the operating surgeon without diverting attention away from the operative task. This technology has the potential to enhance image‐guided procedures.

SummaryObjectiveEvaluate the seizure‐reduction response and safety of mesial temporal lobe (MTL) brain‐responsive stimulation in adults with medically intractable partial‐onset seizures of mesial temporal lobe origin.MethodsSubjects with mesial temporal lobe epilepsy (MTLE) were identified from prospective clinical trials of a brain‐responsive neurostimulator (RNS System, NeuroPace). The seizure reduction over years 2–6 postimplantation was calculated by assessing the seizure frequency compared to a preimplantation baseline. Safety was assessed based on reported adverse events.ResultsThere were 111 subjects with MTLE; 72% of subjects had bilateral MTL onsets and 28% had unilateral onsets. Subjects had one to four leads placed; only two leads could be connected to the device. Seventy‐six subjects had depth leads only, 29 had both depth and strip leads, and 6 had only strip leads. The mean follow‐up was 6.1 ± (standard deviation) 2.2 years. The median percent seizure reduction was 70% (last observation carried forward). Twenty‐nine percent of subjects experienced at least one seizure‐free period of 6 months or longer, and 15% experienced at least one seizure‐free period of 1 year or longer. There was no difference in seizure reduction in subjects with and without mesial temporal sclerosis (MTS), bilateral MTL onsets, prior resection, prior intracranial monitoring, and prior vagus nerve stimulation. In addition, seizure reduction was not dependent on the location of depth leads relative to the hippocampus. The most frequent serious device‐related adverse event was soft tissue implant‐site infection (overall rate, including events categorized as device‐related, uncertain, or not device‐related: 0.03 per implant year, which is not greater than with other neurostimulation devices).SignificanceBrain‐responsive stimulation represents a safe and effective treatment option for patients with medically intractable epilepsy, including patients with unilateral or bilateral MTLE who are not candidates for temporal lobectomy or who have failed a prior MTL resection.

SummaryObjectiveEvaluate the seizure‐reduction response and safety of brain‐responsive stimulation in adults with medically intractable partial‐onset seizures of neocortical origin.MethodsPatients with partial seizures of neocortical origin were identified from prospective clinical trials of a brain‐responsive neurostimulator (RNS System, NeuroPace). The seizure reduction over years 2–6 postimplantation was calculated by assessing the seizure frequency compared to a preimplantation baseline. Safety was assessed based on reported adverse events. Additional analyses considered safety and seizure reduction according to lobe and functional area (e.g., eloquent cortex) of seizure onset.ResultsThere were 126 patients with seizures of neocortical onset. The average follow‐up was 6.1 implant years. The median percent seizure reduction was 70% in patients with frontal and parietal seizure onsets, 58% in those with temporal neocortical onsets, and 51% in those with multilobar onsets (last observation carried forward [LOCF] analysis). Twenty‐six percent of patients experienced at least one seizure‐free period of 6 months or longer and 14% experienced at least one seizure‐free period of 1 year or longer. Patients with lesions on magnetic resonance imaging (MRI; 77% reduction, LOCF) and those with normal MRI findings (45% reduction, LOCF) benefitted, although the treatment response was more robust in patients with an MRI lesion (p = 0.02, generalized estimating equation [GEE]). There were no differences in the seizure reduction in patients with and without prior epilepsy surgery or vagus nerve stimulation. Stimulation parameters used for treatment did not cause acute or chronic neurologic deficits, even in eloquent cortical areas. The rates of infection (0.017 per patient implant year) and perioperative hemorrhage (0.8%) were not greater than with other neurostimulation devices.SignificanceBrain‐responsive stimulation represents a safe and effective treatment option for patients with medically intractable epilepsy, including adults with seizures of neocortical onset, and those with onsets from eloquent cortex.