Background

Cerebral microdialysis enables monitoring of brain metabolism and can be an important part of multimodal monitoring strategies in a variety of brain injuries. Microdialysis catheters can be placed in brain parenchyma through a burr hole, a cranial bolt, or directly at the time of an open craniotomy or craniectomy. The location of catheters in relation to brain pathology is important to the interpretation of data and guidance of interventions.

Methods

Here we retrospectively review the use of cerebral microdialysis at a US Regional Medical Center between March 2018 and February 2022 and provide detailed descriptions and technical nuances of the different methods to place microdialysis catheters.

Results

Eighty two unique microdialysis catheters were utilized in 52 patients. 35 (42.68%) were placed via a quad-lumen bolt and 47 (57.32%) were placed through craniotomies. 27 catheters (32.93%) were placed in a perilesional location, 50 (60.98%) were located in healthy tissue, and 6 (7.32%) were mispositioned. No significant difference was seen between placement by bolt or craniotomy in regard to perilesional location, mispositioning, or complications.

Conclusion

With careful planning and thoughtful execution, cerebral microdialysis catheters can be successfully placed though a variety of strategies to optimize and individualize brain monitoring in different clinical settings. This paper provides a detailed guide for the various methods of catheter placement to help providers begin or expand their use of cerebral microdialysis.

We propose a novel, simple and effective method to integrate lesion prior and a 3D U-Net for improving brain tumor segmentation. First, we utilize the ground-truth brain tumor lesions from a group of patients to generate the heatmaps of different types of lesions. These heatmaps are used to create the volume-of-interest (VOI) map which contains prior information about brain tumor lesions. The VOI map is then integrated with the multimodal MR images and input to a 3D U-Net for segmentation. The proposed method is evaluated on a public benchmark dataset, and the experimental results show that the proposed feature fusion method achieves an improvement over the baseline methods. In addition, our proposed method also achieves a competitive performance compared to state-of-the-art methods.

Background: Chronic subdural hematomas (cSDH) are increasingly prevalent worldwide with the increased aging population and anticoagulant use. Different surgical, medical, and endovascular treatments have had varying success rates. Primary neurosurgical interventions include burr hole drainage of the cSDH and mini-craniotomies/craniotomies with or without fenestration of the inner membrane. A key assessment of the success or failure of cSDH treatments has been symptomatic recurrence rates which have historically ranged from 5 to 30%. Pre-operative prediction of the inner subdural membrane by CT scan was used to guide our decision to perform mini-craniotomies. Release of the inner membrane facilitates the expansion of the brain and likely improves glymphatic flow. Methods: Consecutive mini-craniotomies (N = 34) for cSDH evacuation performed by a single neurosurgeon at a quaternary academic medical center/Level I trauma center from July 2018-September 2020 were retrospectively reviewed. Patient characteristics [age, gender, presenting GCS, GOS, initial CTs noting the inner subdural membrane, midline shift (MLS), cSDH width, inner membrane fenestration, cSDH recurrence, post-operative seizures, infections, length of stay] were extracted from the EMR. Results: Twenty nine patients had mini-craniotomies as primary treatment of the cSDH. Mean age = 68.9 ± 19.7 years (range 22-102), mean pre-operative GCS = 14.5 ± 1.1, mean MLS = 6.75 ± 4.2 mm, and mean maximum thickness of cSDH = 17.7 ± 6.0 mm. Twenty four were unilateral, five bilateral, 34 total craniotomies were performed. Thirty three had inner membrane signs on pre-operative head CTs and an inner subdural membrane was fenestrated in all cases except for the one craniotomy that didn't show these characteristic CT findings. Mean operating time = 79.5 ± 26.0 min. Radiographic and clinical improvement occurred in all patients. Mean improvement in MLS = 3.85 ± 2.69. There were no symptomatic recurrences, re-operations, surgical site infections, or deaths during the 6 months of follow-up. One patient was treated for post-operative seizures with AEDs for 6 months. Conclusion: Pre-operative CT scans demonstrating inner subdural membranes may guide one to target the treatment to allow release of this tension band. Mini-craniotomy with careful fenestration of the inner membrane is very effective for this. Brain re-expansion and re-establishment of normal brain interstitial flow may be important in long term outcomes with cSDH and may be related to the recent interests in brain glymphatics and dural lymphatics.

Traumatic Brain Injury (TBI) is a devastating and widely prevalent cause of death and disability in the United States. Educational interventions integrated into neurosurgical neurotrauma clinics can facilitate patient education and optimize the clinical encounter. Interactive educational modalities may enhance knowledge acquisition and patient satisfaction, however, no description of implementing such a program has been presented in the literature. The implementation of an interactive iBook-based educational intervention in an outpatient neurotrauma clinic is discussed. Concussion and TBI iBooks and surveys were created. Then, a retrospective chart review and data analysis of 202 consecutive patients and family members presenting to the neurotrauma clinic was conducted. The participants completed a presurvey, reviewed an interactive iBook, and then completed a post-survey to test interim knowledge improvement. We discuss the process and problems encountered when creating the iBooks and implementing them in a clinical setting. Between August 1, 2015 and August 1, 2016, 93 patients (46%) and 109 (54%) family members participated in the study, for a total of 202 participants. 104 subjects reviewed a concussion iBook, and 98 subjects reviewed a TBI iBook, depending on their medical condition. Significant improvements in self-reported knowledge measures were demonstrated. Participants ranged in age from 10 to 90 years, with a mean of 45 years. The male to female ratio was 1.104:1. Interactive iBooks were readily implemented into a neurotrauma clinic. Improvements in self-reported knowledge measures and strong preference for the interactive iBook were attributed to the efficacy of the educational intervention. Examples of how interactive iBooks may be a useful adjunct in the education of head injury patients and their families in the neurotrauma setting are presented.

In this work, we utilize T1-weighted MR images and StackNet to predict fluid intelligence in adolescents. Our framework includes feature extraction, feature normalization, feature denoising, feature selection, training a StackNet, and predicting fluid intelligence. The extracted feature is the distribution of different brain tissues in different brain parcellation regions. The proposed StackNet consists of three layers and 11 models. Each layer uses the predictions from all previous layers including the input layer. The proposed StackNet is tested on a public benchmark Adolescent Brain Cognitive Development Neurocognitive Prediction Challenge 2019 and achieves a mean squared error of 82.42 on the combined training and validation set with 10-fold cross-validation. In addition, the proposed StackNet also achieves a mean squared error of 94.25 on the testing data. The source code is available on GitHub.

The manual brain tumor annotation process is time consuming and resource consuming, therefore, an automated and accurate brain tumor segmentation tool is greatly in demand. In this paper, we introduce a novel method to integrate location information with the state-of-the-art patch-based neural networks for brain tumor segmentation. This is motivated by the observation that lesions are not uniformly distributed across different brain parcellation regions and that a locality-sensitive segmentation is likely to obtain better segmentation accuracy. Toward this, we use an existing brain parcellation atlas in the Montreal Neurological Institute (MNI) space and map this atlas to the individual subject data. This mapped atlas in the subject data space is integrated with structural Magnetic Resonance (MR) imaging data, and patch-based neural networks, including 3D U-Net and DeepMedic, are trained to classify the different brain lesions. Multiple state-of-the-art neural networks are trained and integrated with XGBoost fusion in the proposed two-level ensemble method. The first level reduces the uncertainty of the same type of models with different seed initializations, and the second level leverages the advantages of different types of neural network models. The proposed location information fusion method improves the segmentation performance of state-of-the-art networks including 3D U-Net and DeepMedic. Our proposed ensemble also achieves better segmentation performance compared to the state-of-the-art networks in BraTS 2017 and rivals state-of-the-art networks in BraTS 2018. Detailed results are provided on the public multimodal brain tumor segmentation (BraTS) benchmarks.

Objective

To review the complex pathogenesis of the subdural membrane and the link between head trauma, dementia, and dural lymphatics.

Methods

A thorough literature search of published English-language articles was performed using PubMed, Ovid, and Cochrane databases.

Results

Chronic subdural hematoma (cSDH) is a common intracranial pathology and a leading cause of reversible dementia. cSDH is projected to affect at least 60,000 new individuals in the United States annually by 2030. This condition can result from mild to moderate head trauma that leads to hemorrhaging in the dura-arachnoid interface. The short-term and long-term effects of cSDH and the subdural membrane on the pathogenesis of dementia and the newly discovered dural lymphatics is a topic of increasing importance.

Conclusions

Further research into the possible link between traumatic brain injury and cSDH in particular and dural lymphatics and intracranial fluid dynamics is warranted.

Background

Neurological surgeons oftentimes educate patients and their families on complex medical conditions and treatment options. Time constraints and varied linguistic and cultural backgrounds limit the amount of information that can be disbursed. In this study, we assessed the linguistic validity of interactive educational interventions in non-English-speaking patients with traumatic brain injury (TBI) and concussion and their families.

Methods

A total of 273 English-, Spanish-, Korean-, and Vietnamese-speaking neurotrauma patients (n =124) and family members (n =149) completed a presurvey to evaluate their incipient understanding, interacted with an iPad-based iBook (Apple) on concussion or TBI in their native language, completed a postsurvey to gauge changes in understanding, and then consulted with their neurosurgeon.

Results

All participants (124 patients and 149 family members) had significantly increased (95% confidence interval [CI], P < 0.01) postsurvey scores (average pre-iBook score, 2.810; average post-iBook score, 4.109), regardless of native language or cultural background. Caucasian participants scored significantly higher than the combination of all ethnicities on both the baseline survey (95% CI, P < 0.01) and the post-iBook survey (95% CI, P < 0.01), and Asian participants scored significantly lower (95% CI, P < 0.05) than the combination regardless of similar baseline scores.

Conclusions

Interactive iBook-based interventions on concussion and TBI can increase participants' comprehension, improve their comfort with their medical condition and the follow-up care, and enhance communication with their physicians. These findings are linguistically valid irrespective of the participants' native language or cultural background.

CellScope®, an iPhone-enabled otoscope, was introduced into the neurotrauma clinic at an American College of Surgeons certified Level I trauma center. CellScope is an innovative tool that digitally improves optical clarity of the tympanic membrane, providing the acquisition of HIPPA compliant images. We compared the CellScope to the traditional otoscope in teaching medical students, neurosurgery physician assistants, and neurosurgery residents. In addition, the utility of this device in a neurotrauma clinic was specifically examined because of the high frequency of otologic symptoms after head trauma. CellScope examination of the tympanic membranes was introduced as a standard/routine part of the exam of neurotrauma patients. We retrospectively reviewed the clinic charts of the NeuroTrauma patients during a three-month time period to determine if their otologic symptoms correlated with any CellScope visualized abnormalities. Medical students, P.A.s, residents, and attendings were surveyed before and after using CellScope to assess their comfort and skill in completing an otological exam, as well as their opinion on the utility of CellScope in their medical training. 18 medical professionals were surveyed before and after the use of CellScope. Surveys were graded on a 1-5 scale and indicated a greater preference for the CellScope (4.7/5.0) versus the otoscope (3.16/5.0). Similarly, there was a preference for the CellScope for medical education (4.7/5.0 versus 2.78/5.0). Finally, surveys showed a greater preference for CellScope in identifying abnormal pathology. The overall score showed a 49% increased preference for CellScope over the traditional otoscope. Six previously undiagnosed abnormalities of the tympanic membrane were identified in a total of 27 neurotrauma patients using CellScope. The visualization of the tympanic membrane is an important part of the physical examination of the neurotrauma patient. Smartphone-enabled medical instruments like CellScope may facilitate and remove barriers to routine implementation of this part of the physical examination.