Immunocompetent isolated cerebral mucormycosis presenting with obstructive hydrocephalus: illustrative case.

BACKGROUND: Isolated cerebral mucormycosis is rare in immunocompetent adults and is only sparsely reported to be associated with obstructive hydrocephalus. OBSERVATIONS: Here, the authors report a case of obstructive hydrocephalus secondary to central nervous system mucormycosis without other systems or rhino-orbital involvement and its technical surgical management. A 23-year-old, incarcerated, immunocompetent patient with history of intravenous (IV) drug use presented with syncope. Although clinical and radiographic findings failed to elucidate an infectious pathology, endoscopy revealed an obstructive mass lesion at the level of the third ventricle, which, on microbiological testing, was confirmed to be Rhizopus fungal ventriculitis. Perioperative cerebrospinal fluid diversion, endoscopic third ventriculostomy, endoscopic biopsy technique, patient outcomes, and the literature are reviewed here. The patient received intrathecal and IV amphotericin B followed by a course of oral antifungal treatment and currently remains in remission. LESSONS: The patient's unique presentation and diagnosis of isolated cerebral mucormycosis reveal this pathogen as a cause of ventriculitis and obstructive hydrocephalus in immunocompetent adult patients, even in the absence of infectious sequelae on neuroimaging.

Degenerative L4-L5 spondylolisthesis and stenosis surgery: does over-level flavectomy technique influence clinical outcomes and rates of cranial adjacent segment disease?

BACKGROUND: One of the most dreaded long-term complications related to L4-L5 lumbar arthrodesis is the onset of adjacent segment disease, which most frequently occurs at the cranial level. Few studies have compared the rates of cranial adjacent segment disease (CASD) in patients undergoing lumbar fusion associated with total laminectomy at the same level with those undergoing partial laminectomy. No study has examined the role of selective over-level flavectomy (OLF; i.e., L3-L4). METHODS: A total of 299 patients undergoing posterolateral arthrodesis (PLA) for L4-L5 degenerative spondylolisthesis were retrospectively analyzed with a 5-year follow-up. 148 patients underwent PLA + L4-L5 flavectomy + L4 partial laminectomy (control group), while 151 underwent PLA + L4-L5 flavectomy + total L4 laminectomy + L3-L4 flavectomy (OLF group). Rates of reoperations due to CASD were examined utilizing Cox proportional hazard models, while clinical improvement at follow-up (measured in ODI) was analyzed using generalized linear models (GLMs). Adjustments for potential confounders were made (grade of lumbar lordosis, age, sex, BMI, intervertebral disc degeneration, and presurgical cranial spinal stenosis). RESULTS: At 5 years from the operation, 16 patients (10.8%) in the control group had undergone revision surgery for CASD compared to 5 patients (3.3%) in the OLF group (p = 0.013). Survival analysis and GLM demonstrated that the OLF group had a significantly lower incidence of CASD and presented more favorable clinical outcome. There were no differences in the rate of discal degeneration or the onset of Meyerding's grade I degenerative spondylolisthesis at the adjacent segment. BMI was the only other significant predictor of ODI improvement and of the incidence of CASD. CONCLUSIONS: In patients with L4-L5 degenerative spondylolisthesis and stenosis, the OLF technique may lower rates of CASD and improve clinical outcomes by preventing cranial spinal stenosis without increasing iatrogenic instability or accelerating intervertebral disc degenerative changes.

Relationship of Bern Score, Spinal Elastance, and Opening Pressure in Patients With Spontaneous Intracranial Hypotension.

BACKGROUND AND OBJECTIVES: Existing tools to diagnose spontaneous intracranial hypotension (SIH), namely spinal opening pressure (OP) and brain MRI, have limited sensitivity. We investigated whether evaluation of brain MRI using the Bern score, combined with calculated craniospinal elastance, would aid in diagnosing SIH and provide insight into its pathophysiology. METHODS: A retrospective chart review was performed of patients who underwent brain MRI and pressure-augmented dynamic CT myelography (dCTM) for suspicion of SIH. Two blinded neuroradiologists assigned Bern scores for each brain MRI. OP and incremental pressure changes after intrathecal saline infusion were recorded to calculate craniospinal elastance. The relationship between Bern score, OP, and elastance and whether a leak was found were analyzed. RESULTS: Seventy-two consecutive dCTMs were performed in 53 patients. Twelve CSF-venous fistulae, 2 ruptured meningeal diverticula, 2 dural defects, and 1 dural bleb were found (17/53, 32%). Among patients with imaging-proven CSF leak/fistula, OP was normal in all but 1 patient and was not significantly different in those with a leak compared with those without (15.1 vs 13.6 cm H2O, p = 0.24, A = 0.40). The average Bern score in individuals with a leak was significantly higher than that in those without (5.35 vs 1.85, p < 0.001, A = 0.85), even when excluding pachymeningeal enhancement from the score (3.77 vs 1.57, p = 0.001, A = 0.78). The average elastance in those with a leak was higher than that in those without, but this difference was not statistically significant (2.05 vs 1.20 mL/cm H2O, p = 0.19, A = 0.40). Increased elastance was significantly associated with an increased Bern score (95% CI -0.55 to 0.12, p < 0.01) and was significantly associated with venous distention, pachymeningeal enhancement, prepontine narrowing, and subdural collections, but not a narrowed mamillopontine or suprasellar distance. DISCUSSION: OP is not an effective predictor for diagnosing CSF leak and if used in isolation would result in misdiagnosis of 94% of patients in our cohort. The Bern score was associated with a higher diagnostic yield of dCTM. Elastance was significantly associated with certain components of the Bern score.

Algorithmic Multimodality Approach to Diagnosis and Treatment of Spinal CSF Leak and Venous Fistula in Patients With Spontaneous Intracranial Hypotension.

Spontaneous intracranial hypotension (SIH) is a disorder of CSF dynamics that causes a complex clinical syndrome and severe disability. SIH is challenging to diagnose because of the variability of its presenting clinical symptoms, the potential for subtle imaging findings to be easily overlooked, and the need for specialized diagnostic testing. Once SIH is suggested by clinical history and/or supported by initial neuroim-aging, many patients may undergo initial nontargeted epidural blood patching with variable and indefinite benefit. However, data suggest that precise localization of the CSF leak or CSF-venous fistula (CVF) can lead to more effective and durable treatment strategies. Leak localization can be achieved using a variety of advanced diagnostic imaging techniques, although these may not be widely performed at nontertiary medical centers, leaving many patients with the potential for inadequate workup or treatment. This review describes imaging techniques including dynamic fluoroscopic and CT myelography as well as delayed MR myelography and treatment options including percutaneous, endovascular, and surgical approaches for SIH. These are summarized by an algorithmic framework for radiologists to approach the workup and treatment of patients with suspected SIH. The importance of a multidisciplinary approach is emphasized.

Use of Three-Dimensional Printed Brain Models During Deep Brain Stimulation Surgery Consultation for Patient Health Literacy: A Randomized Controlled Investigation.

BACKGROUND: Advanced therapies in neurosurgery, such as deep brain stimulation (DBS), would benefit from improved patient education materials. Three-dimensional (3D) printed anatomical models represent a recent development for improving patient education for neurosurgical procedures. METHODS: In this study, 40 patients undergoing DBS surgery consultation were randomly assigned to 1 of 2 groups: an experimental group, which received a demonstration of DBS therapeutic neuroanatomical targets in a 3D printed brain model plus standard patient education (PE), or a control group, which received standard PE alone. RESULTS: Patients in the DBS model plus PE group showed a significant increase in patient confidence and understanding of the brain structures targeted during a DBS procedure compared with patients in the PE-only group (P < 0.01). There was no difference in perceived risk, comfort, or anxiety related to the procedure. CONCLUSIONS: In the first randomized controlled study to our knowledge of 3D printed models for DBS consultation, our results demonstrate that patients had improved understanding of their therapy with the models. However, the models alone did not affect risk evaluation or comfort with surgery. A 3D printed brain model may help improve patient understanding of DBS surgery.

Deep Brain Stimulation of the Ventral Intermediate Nucleus of the Thalamus in Writer's Cramp: A Case Report.

Background: Globus pallidus internus (GPi) deep brain stimulation (DBS) and thalamotomy are interventions for writer's cramp (WC). Ventralis intermedius nucleus (VIM) DBS is targeted for tremor, however, many aspects of VIM DBS remained underexplored in WC. Case Report: A 62-year-old man with WC underwent DBS. Dystonic tremor improved intraoperatively with ventralis oralis anterior (VoA)/ventral oralis posterior (VoP) and with subthalamic nucleus stimulation; although greatest benefit was obtained with VIM stimulation. Sustained benefit with VIM DBS at ten months post-operative was obtained. Discussion: This case demonstrates an intraoperative approach in target selection and supports benefits of VIM DBS for WC. Highlights: This case highlights the intraoperative approach and clinical effects of VIM DBS in the treatment of medically refractory writer's cramp (WC). We contextualize our results from this case with previous reports of VoA/VoP stimulation for WC.

How neuropsychiatric comorbidity, modulatory indication, demographics, and other factors impact deep brain stimulation inpatient outcomes in the United States: A population-based study of 27,956 patients.

OBJECTIVE: To determine how neuropsychiatric comorbidity, modulatory indication, demographics, and other characteristics affect inpatient deep brain stimulation (DBS) outcomes. METHODS: This is a retrospective study of 45 months' worth of data from the National Inpatient Sample. Patients were aged ≥ 18 years old and underwent DBS for Parkinson Disease (PD), essential tremor (ET), general dystonia and related disorders, other movement disorder (non-PD/ET), or obsessive-compulsive disorder (OCD) at a US hospital. Primary endpoints were prolonged length of stay (PLOS), high-end hospital charges (HEHCs), unfavorable disposition, and inpatient complications. Logistic models were constructed with odds ratios under 95% confidence intervals. A p-value of 0.05 determined significance. RESULTS: Of 214,098 records, there were 27,956 eligible patients. Average age was 63.9 ± 11.2 years, 17,769 (63.6%) were male, and 10,182 (36.4%) patients were female. Most of the cohort was White (51.1%), Medicare payer (64.3%), and treated at a large-bed size (80.7%), private non-profit (76.9%), and metro-teaching (94.0%) hospital. Neuropsychiatric comorbidity prevalence ranged from 29.9% to 47.7% depending on indication. Compared with PD, odds of complications and unfavorable disposition were significantly higher with other movement disorders and dystonia, whereas OCD conferred greater risk for HEHCs (p < 0.05). Patients with ET had favorable outcomes. Neuropsychiatric comorbidity, Black race, and Charlson Comorbidity Index > 0 were significantly associated with unfavorable outcomes (p < 0.05). CONCLUSION: The risk of adverse inpatient outcomes for DBS in the United States is independently correlated with non-PD/ET disorders, neuropsychiatric comorbidity, and non-White race, reflecting the heterogeneity and infancy of widespread DBS for these patients.

Management of post-operative delirium following stereoelectroencephalography electrode placement for drug resistant epilepsy: Lessons learned from two case reports.

Post-operative delirium (POD) represents a unique challenge in the care of any surgical patient but is especially challenging in neurosurgical inpatient management due to a host of potentially significant predisposing factors. Patients undergoing stereoencephalography (SEEG) for diagnosis of drug resistant epilepsy are at unique risk due to safety concerns, yet POD has been underdiscussed in this population. Patients should be counseled pre-operatively about their risk and subsequent steps be taken post-operatively. We present two cases of POD status-post SEEG and propose a mechanism by which future post-operative care be coordinated by the physician, patient, and patient's family.

Spontaneous Variation in Electrocorticographic Resting-State Connectivity.

Prior studies using functional magnetic resonance imaging, electroencephalography, and magnetoencephalography have observed both structured patterns in resting-state functional connectivity and spontaneous longitudinal variation in connectivity patterns independent of a task. In this first study using electrocorticography (ECoG), we characterized spontaneous, intersession variation in resting-state functional connectivity not linked to a task. We evaluated pairwise connectivity between electrodes using three measures (phase locking value [PLV], amplitude correlation, and coherence) for six canonical frequency bands, capturing different characteristics of time-evolving signals. We grouped electrodes into 10 functional regions and used intraclass correlation (ICC) to estimate pairwise longitudinal stability. We found that stronger PLV (PLV ≥0.4) in theta through gamma bands and strong correlation in all bands (R2's ≥0.6) are linked to substantial stability (ICC ≥0.6), but that stability does not imply strong phase locking or amplitude correlation. There was no notable link between strong coherence and high ICC. All within-region PLVs are markedly stable across frequencies. In addition, we highlight interaction patterns across several regions: parahippocampal/entorhinal cortex is characterized by stable, weak functional connectivity except self-connections. Dorsolateral prefrontal cortex connectivity is weak and unstable, except self-connections. Inferior parietal lobule has little stability despite narrow connectivity bounds. We confirm prior studies linking functional connectivity strength and intersession variability, extending into higher frequencies than other modalities, with greater spatial specificity than scalp electrophysiology. We suggest further studies quantitatively compare ECoG to other modalities and/or use these findings as a baseline to capture functional connectivity and dynamics linked to perturbations with a task or disease state.

Changes in resting-state connectivity in pediatric temporal lobe epilepsy.

OBJECTIVE Functional connectivity magnetic resonance imaging (fcMRI) is a form of fMRI that allows for analysis of blood oxygen level-dependent signal changes within a task-free, resting paradigm. This technique has been shown to have efficacy in evaluating network connectivity changes with epilepsy. Presurgical data from patients with unilateral temporal lobe epilepsy were evaluated using the fcMRI technique to define connectivity changes within and between the diseased and healthy temporal lobes using a within-subjects design. METHODS Using presurgical fcMRI data from pediatric patients with unilateral temporal lobe epilepsy, the authors performed seed-based analyses within the diseased and healthy temporal lobes. Connectivity within and between temporal lobe seeds was measured and compared. RESULTS In the cohort studied, local ipsilateral temporal lobe connectivity was significantly increased on the diseased side compared to the healthy temporal lobe. Connectivity of the diseased side to the healthy side, on the other hand, was significantly reduced when compared to connectivity of the healthy side to the diseased temporal lobe. A statistically significant regression was observed when comparing the changes in local ipsilateral temporal lobe connectivity to the changes in inter-temporal lobe connectivity. A statistically significant difference was also noted in ipsilateral connectivity changes between patients with and those without mesial temporal sclerosis. CONCLUSIONS Using fcMRI, significant changes in ipsilateral temporal lobe and inter-temporal lobe connectivity can be appreciated in unilateral temporal lobe epilepsy. Furthermore, fcMRI may have a role in the presurgical evaluation of patients with intractable temporal lobe epilepsy.

Preservation of electrophysiological functional connectivity after partial corpus callosotomy: case report.

Prior studies of functional connectivity following callosotomy have disagreed in the observed effects on interhemispheric functional connectivity. These connectivity studies, in multiple electrophysiological methods and functional MRI, have found conflicting reductions in connectivity or patterns resembling typical individuals. The authors examined a case of partial anterior corpus callosum connection, where pairs of bilateral electrocorticographic electrodes had been placed over homologous regions in the left and right hemispheres. They sorted electrode pairs by whether their direct corpus callosum connection had been disconnected or preserved using diffusion tensor imaging and native anatomical MRI, and they estimated functional connectivity between pairs of electrodes over homologous regions using phase-locking value. They found no significant differences in any frequency band between pairs of electrodes that had their corpus callosum connection disconnected and those that had an intact connection. The authors' results may imply that the corpus callosum is not an obligatory mediator of connectivity between homologous sites in opposite hemispheres. This interhemispheric synchronization may also be linked to disruption of seizure activity.