Pathological microcircuits initiate epileptiform events in patient hippocampal slices.

How seizures begin at the level of microscopic neural circuits remains unknown. High-density CMOS microelectrode arrays provide a new avenue for investigating neuronal network activity, with unprecedented spatial and temporal resolution. We use high-density CMOS-based microelectrode arrays to probe the network activity of human hippocampal brain slices from six patients with mesial temporal lobe epilepsy in the presence of hyperactivity promoting media.

Multiscale Cloud-Based Pipeline for Neuronal Electrophysiology Analysis and Visualization.

Electrophysiology offers a high-resolution method for real-time measurement of neural activity. Longitudinal recordings from high-density microelectrode arrays (HD-MEAs) can be of considerable size for local storage and of substantial complexity for extracting neural features and network dynamics. Analysis is often demanding due to the need for multiple software tools with different runtime dependencies.

Multimodal evaluation of network activity and optogenetic interventions in human hippocampal slices.

Seizures are made up of the coordinated activity of networks of neurons, suggesting that control of neurons in the pathologic circuits of epilepsy could allow for control of the disease. Optogenetics has been effective at stopping seizure-like activity in non-human disease models by increasing inhibitory tone or decreasing excitation, although this effect has not been shown in human brain tissue. Many of the genetic means for achieving channelrhodopsin expression in non-human models are not possible in humans, and vector-mediated methods are susceptible to species-specific tropism that may affect translational potential.

Single-level laminoplasty approach to selective dorsal rhizotomy with conus localization by rapid spine MRI.

Introduction: While selective dorsal rhizotomy (SDR) was originally described as a multilevel approach, single-level approaches are now popularized. Conus localization is beneficial for operative planning in single-level selective dorsal rhizotomy. Our approach to SDR involves minimal exposure for a single-level laminoplasty, preserving one attached interspinous ligament.

Intraventricular meningioma resection and visual outcomes.

Objective: Intraventricular meningiomas (IVMs) of the lateral ventricle are rare tumors that present surgical challenges because of their deep location. Visual field deficits (VFDs) are one risk associated with these tumors and their treatment. VFDs may be present preoperatively due to the tumor and mass effect (tumor VFDs) or may develop postoperatively due to the surgical approach (surgical VFDs).

Update on Pediatric Mild Traumatic Brain Injury in Rural and Underserved Regions: A Global Perspective.

Background: Mild traumatic brain injury (MTBI) causes morbidity and disability worldwide. Pediatric patients are uniquely vulnerable due to developmental and psychosocial factors. Reduced healthcare access in rural/underserved communities impair management and outcome.

Improved psychotic symptoms following resection of amygdalar low-grade glioma: illustrative case.

Background: Epilepsy-associated psychoses are poorly understood, and management is focused on treating epilepsy. Chronic, interictal psychosis that persists despite seizure control is typically treated with antipsychotics. Whether resection of a mesial temporal lobe lesion may improve interictal psychotic symptoms that persist despite seizure control remains unknown.

Paraparesis caused by intradural thoracic spinal granuloma secondary to organizing hematoma: illustrative case.

Background: Spinal granulomas form from infectious or noninfectious inflammatory processes and are rarely present intradurally. Intradural granulomas secondary to hematoma are unreported in the literature and present diagnostic and management challenges.

Observations: A 70-year-old man receiving aspirin presented with encephalopathy, subacute malaise, and right lower extremity weakness and was diagnosed with polysubstance withdrawal and refractory hypertension requiring extended treatment.

Xenotransplantation of porcine progenitor cells in an epileptic California sea lion (Zalophus californianus): illustrative case.

Background: Domoic acid (DA) is a naturally occurring neurotoxin harmful to marine animals and humans. California sea lions exposed to DA in prey during algal blooms along the Pacific coast exhibit significant neurological symptoms, including epilepsy with hippocampal atrophy.

Observations: Here the authors describe a xenotransplantation procedure to deliver interneuron progenitor cells into the damaged hippocampus of an epileptic sea lion with suspected DA toxicosis.

Dissociation of Broca's area from Broca's aphasia in patients undergoing neurosurgical resections.

Objective: Broca's aphasia is a syndrome of impaired fluency with retained comprehension. The authors used an unbiased algorithm to examine which neuroanatomical areas are most likely to result in Broca's aphasia following surgical lesions.

Methods: Patients were prospectively evaluated with standardized language batteries before and after surgery.

Paramedian transparietal approach to a dominant hemisphere intraventricular meningioma: illustrative case.

Background: Meningiomas of the atrium of the lateral ventricle present a unique operative challenge. Parietal transcortical approaches have been described with an oblique approach, but a strictly paramedian approach may offer advantages in a dominant hemisphere atrial meningioma.

Observations: The patient presented with several weeks of intermittent headaches.

Prosopagnosia following nonlanguage dominant inferior temporal lobe low-grade glioma resection in which the inferior longitudinal fasciculus was disrupted preoperatively: illustrative case.

Background: Prosopagnosia is a rare neurological condition characterized by the impairment of face perception with preserved visual processing and cognitive functioning and is associated with injury to the fusiform gyrus and inferior longitudinal fasciculus (ILF). Reports of this clinical impairment following resection of right temporal lobe diffuse gliomas in the absence of contralateral injury are exceedingly scarce and not expected as a complication of surgery.

Observations: The authors describe the case of a young female patient found to have an incidental diffuse glioma in the right inferior temporal lobe despite evidence of preoperative ILF disruption by the tumor.

Hydrothermal conversion of toilet waste: effect of processing conditions on gas phase emissions.

Globally, many populations suffer from a lack of access to basic sanitation facilities. This is partly caused by a combination of water resource shortages and the high cost of conventional centralised treatment systems. A novel decentralised treatment technology based on sub-critical hydrothermal processing of organic wastes at toilet-scale, contributes to addressing these economic and resource limitations.

Plurihormonal PIT-1-Positive Pituitary Adenomas: A Systematic Review and Single-Center Series.

Objective: The 2017 World Health Organization classification of pituitary adenomas identified the plurihormonal PIT-1-positive (PP1) adenoma as a distinct subtype. The reported data suggest that PP1 adenomas encompass the former class of silent subtype 3 (SS3) adenomas and might have an aggressive phenotype. In the present study, we summarized the current clinical data on PP1 and SS3 adenomas and compared the reported data with the data from a single institutional cohort.

Decompression of a Dorsal Arachnoid Web of the Spine: 2-Dimensional Operative Video.

Arachnoid webs of the spine are a relatively rare entity with unique radiological findings, most notably the scalpel-sign on sagittal magnetic resonance imaging (MRI).1-4 To date there have been no videographic descriptions of the surgical treatment for this clinical entity. We present the case of a patient with progressive myelopathy and MRI showing a cervical and thoracic syrinx with a sharp transition point at the level of the T5 vertebral body.

Early seizure spread and epilepsy surgery: A systematic review.

Objective: A fundamental question in epilepsy surgery is how to delineate the margins of cortex that must be resected to result in seizure freedom. Whether and which areas showing seizure activity early in ictus must be removed to avoid postoperative recurrence of seizures is an area of ongoing research. Seizure spread dynamics in the initial seconds of ictus are often correlated with postoperative outcome; there is neither a consensus definition of early spread nor a concise summary of the existing literature linking seizure spread to postsurgical seizure outcomes.

Thalamic Stimulation Improves Postictal Cortical Arousal and Behavior.

The postictal state following seizures is characterized by impaired consciousness and has a major negative impact on individuals with epilepsy. Previous work in disorders of consciousness including the postictal state suggests that bilateral deep brain stimulation (DBS) of the thalamic intralaminar central lateral nucleus (CL) may improve level of arousal. We tested the effects of postictal thalamic CL DBS in a rat model of secondarily generalized seizures elicited by electrical hippocampal stimulation.

Pure Apraxia of Speech After Resection Based in the Posterior Middle Frontal Gyrus.

Background And Importance: Apraxia of speech is a disorder of articulatory coordination and planning in speech sound production. Its diagnosis is based on deficits in articulation, prosody, and fluency. It is often described concurrent with aphasia or dysarthria, while pure apraxia of speech is a rare entity.

Up and Down States of Cortical Neurons in Focal Limbic Seizures.

Recent work suggests an important role for cortical-subcortical networks in seizure-related loss of consciousness. Temporal lobe seizures disrupt subcortical arousal systems, which may lead to depressed cortical function and loss of consciousness. Extracellular recordings show ictal neocortical slow waves at about 1 Hz, but it is not known whether these simply represent seizure propagation or alternatively deep sleep-like activity, which should include cortical neuronal Up and Down states.

Mechanisms of decreased cholinergic arousal in focal seizures: In vivo whole-cell recordings from the pedunculopontine tegmental nucleus.

Focal limbic seizures often impair consciousness/awareness with major negative impact on quality of life. Recent work has shown that limbic seizures depress brainstem arousal systems, including reduced action potential firing in a key node: cholinergic neurons of the pedunculopontine tegmental nucleus (PPT). In vivo whole-cell recordings have not previously been achieved in PPT, but are used here with the goal of elucidating the mechanisms of reduced PPT cholinergic neuronal activity.

Association of Seizure Spread With Surgical Failure in Epilepsy.

Importance: Seizures recur in as many as half of patients who undergo surgery for drug-resistant temporal lobe epilepsy (TLE). Understanding why TLE is resistant to surgery in some patients may reveal insights into epileptogenic networks and direct new therapies to improve outcomes.

Objective: To characterize features of surgically refractory TLE.

Peduncular psychosis.

Psychotic symptoms are rarely documented in association with cortex-sparing central nervous system (CNS) lesions limited to the midbrain. We present the case of a 15-year-old boy with hereditary and environmental risk factors for psychiatric illness, as well as a history of midbrain pilocytic astrocytoma treated with chemotherapy and focused radiation, who presented with non-epileptic seizures, hyper-religiosity and frank psychosis. The space-occupying midbrain lesion has been radiographically stable while the patient has decompensated psychiatrically.

Neurostimulation to improve level of consciousness in patients with epilepsy.

When drug-resistant epilepsy is poorly localized or surgical resection is contraindicated, current neurostimulation strategies such as deep brain stimulation and vagal nerve stimulation can palliate the frequency or severity of seizures. However, despite medical and neuromodulatory therapy, a significant proportion of patients continue to experience disabling seizures that impair awareness, causing disability and risking injury or sudden unexplained death. We propose a novel strategy in which neuromodulation is used not only to reduce seizures but also to ameliorate impaired consciousness when the patient is in the ictal and postictal states.