"Mail-slot" Technique for Minimally Invasive Placement of Subdural Grid Electrodes: A Single-institution Experience.

BACKGROUND: In the management of multi-drug-resistant focal epilepsies, intracranial electrode implantation is used for precise localization of the ictal onset zone. In select patients, subdural grid electrode implantation is utilized. Subdural grid placement traditionally requires large craniotomies to visualize the cortex prior to mapping. However, smaller craniotomies may enable shorter operations and reduced risks. We aimed to compare surgical outcomes between patients undergoing traditional large craniotomies with those undergoing tailored "mini" craniotomies (the "mail-slot" technique) for subdural grid placement. METHODS: This retrospective cohort study included 23 patients who underwent subdural electrode implantation for epilepsy monitoring between 2014 and 2020. Patients were categorized into mini-craniotomies (n = 9) and traditional large craniotomies (n = 14) groups. Demographics, operative details, and outcomes were reviewed. Craniotomy size and number of electrodes were determined via post hoc radiographs. RESULTS: Of the 23 patients studied, the mini group had smaller craniotomy sizes (mean: 22.71 cm2 vs. 65.17 cm2, P < 0.001) and higher electrode-to-size ratios (mean: 4.25 vs. 1.71, P < 0.0001). The mini group had slightly fewer total electrodes (mean: 88.67 vs. 107.43, P = 0.047). No significant differences were found in operative duration, blood loss, invasive electroencephalography duration, complications, or Engel scores between the groups. One patient per group required further invasive epilepsy monitoring for localization; all patients underwent therapeutic surgery. CONCLUSIONS: Our findings suggest that mini-craniotomies for subdural grid placement in epilepsy monitoring offer significant advantages, including smaller craniotomy sizes and shorter operation durations, without compromising safety or efficacy. These results support the trend towards minimally invasive, patient-tailored surgical approaches in epilepsy treatment.

Microsurgical anatomy of the olfactory filaments in the nasal mucosa.

OBJECTIVE: The aim of this study was to examine the distribution of olfactory filaments (OFs) in the nasal mucosa to facilitate preservation of olfactory function in endonasal approaches and preparation of a nasoseptal flap. METHODS: One formalin-fixed and 9 fresh cadaveric silicone-injected specimens with 20 total sides were studied to measure the distance of the OFs to the anatomical landmarks and compare the OF presence in the nasal septum mucosa (NSM) and ethmoidal mucosa (EM). RESULTS: The mean distance from the first to the last OF was 19.37 ± 2.16 mm in the NSM and 23.44 ± 5.42 mm in the EM. The NSM had a mean of 7.55 ± 1.31 OFs and the EM had 14.3 ± 1.78. Average OF lengths were measured at 6.44 ± 1.48 (range 3.75-12.40) mm in the NSM and 8.05 ± 1.76 (range 4.14-13.20) mm in the EM. The mean values of the EM measurements were compared with those of the NSM; the number of OFs, the distance between the first and last OF, the average OF length, and the number of OFs between anterior and posterior ethmoidal arteries in the NSM were significantly less (p < 0.05) than those in the EM. The distance between the first OF to the nasal bone on the NSM was greater than on the EM. CONCLUSIONS: Compared with the EM, the OFs are significantly fewer in number and smaller in size in the NSM. The uppermost edge of the nasoseptal flap incision in the NSM might be safer to start below 12 mm from the cribriform plate for OF protection.

Application of Responsive Neurostimulation as both a Diagnostic Tool for Seizure Localization and a Supplementary Tool for Surgical Management in Patients with Multiple Epileptogenic Foci: A Case Series.

AIM: To present a series of medically refractory focal epilepsy patients with multiple or eloquent epileptogenic zones (EZs) in whom a responsive neurostimulation (RNS) system was used as a complementary modality to surgical resection. RNS was also used as a diagnostic tool to monitor long-term epileptogenic activity for enhanced localization, especially in patients with bilateral temporal seizures. MATERIAL AND METHODS: Ten consecutive patients who underwent RNS system placement and surgical resection at a single institution were assessed. RESULTS: The RNS system, with its capacity for chronic ambulatory electrocorticography (ECoG), provided important diagnostic information that helped to modify the plan of surgical resection in one patient with bitemporal epilepsy in order to improve seizure outcomes. In addition, the RNS facilitated the surgical management of patients with multiple or eloquent EZs. CONCLUSION: The authors report a population of 10 patients in which the RNS system was used as a diagnostic tool for improved localization of EZs over a long interval or as a complementary therapeutic tool in patients with multiple or eloquent EZs.

Dynamic compression in vertebral artery dissection in children: apropos of a new protocol.

PURPOSE: Our goals are (1) to report a consecutive prospective series of children who had posterior circulation stroke caused by vertebral artery dissection at the V3 segment; (2) to describe a configuration of the vertebral artery that may predispose to rotational compression; and (3) to recommend a new protocol for evaluation and treatment of vertebral artery dissection at V3. METHODS: All children diagnosed with vertebral artery dissection at the V3 segment from September 2014 to July 2020 at our institution were included in the study. Demographic, clinical, surgical, and radiological data were collected. RESULTS: Sixteen children were found to have dissection at a specific segment of the vertebral artery. Fourteen patients were male. Eleven were found to have compression on rotation during a provocative angiogram. All eleven underwent C1C2 posterior fusion as part of their treatment. Their mean age was 6.44 years (range 18 months-15 years). Mean blood loss was 57.7 mL. One minor complication occurred: a superficial wound infection treated with oral antibiotics only. There were no vascular or neurologic injuries. There have been no recurrent ischemic events after diagnosis and/or treatment. Mean follow-up was 33.3 months (range 2-59 months). We designed a new protocol to manage V3 dissections in children. CONCLUSION: Posterior C1C2 fusion is a safe and effective option for treatment of dynamic compression in vertebral artery dissection in children. Institution of and compliance with a strict diagnostic and treatment protocol for V3 segment dissections seem to prevent recurrent stroke.

Surgical Robot-Enhanced Implantation of Intracranial Depth Electrodes for Single Neuron Recording Studies in Patients with Medically Refractory Epilepsy: A Technical Note.

OBJECTIVE: Single neuron or unit recording enables researchers to measure the electrophysiologic responses of single neurons using a microelectrode system. This approach is widely used in cognitive science and has become more widespread in humans with the use of hybrid (micro-within-macrowire) depth electrodes that enable the implantation of microwires into the brain parenchyma. METHODS: The authors describe their surgical technique in a total of 7 patients with intractable epilepsy who underwent robot-enhanced stereoencephalography in which both standard (nonhybrid) and hybrid depth electrodes were used for invasive chronic monitoring. RESULTS: The technique and accuracy of the procedure were evaluated with a total of 84 depth electrodes (46 hybrid, 38 standard) in 7 patients. No major complications, such as intracranial hemorrhage, infection or cerebrospinal fluid leakage, occurred regardless of the type of electrode used. CONCLUSIONS: The addition of hybrid depth electrodes for the purpose of in vivo single neuron recording in robot-enhanced stereoencephalography procedures is safe and does not impact the accuracy of targeting or patient safety.

Anatomical Features of the Deep Cervical Lymphatic System and Intrajugular Lymphatic Vessels in Humans.

BACKGROUND: Studies in rodents have re-kindled interest in the study of lymphatics in the central nervous system. Animal studies have demonstrated that there is a connection between the subarachnoid space and deep cervical lymph nodes (DCLNs) through dural lymphatic vessels located in the skull base and the parasagittal area. OBJECTIVE: To describe the connection of the DCLNs and lymphatic tributaries with the intracranial space through the jugular foramen, and to address the anatomical features and variations of the DCLNs and associated lymphatic channels in the neck. METHODS: Twelve formalin-fixed human head and neck specimens were studied. Samples from the dura of the wall of the jugular foramen were obtained from two fresh human cadavers during rapid autopsy. The samples were immunostained with podoplanin and CD45 to highlight lymphatic channels and immune cells, respectively. RESULTS: The mean number of nodes for DCLNs was 6.91 ± 0.58 on both sides. The mean node length was 10.1 ± 5.13 mm, the mean width was 7.03 ± 1.9 mm, and the mean thickness was 4 ± 1.04 mm. Immunohistochemical staining from rapid autopsy samples demonstrated that lymphatic vessels pass from the intracranial compartment into the neck through the meninges at the jugular foramen, through tributaries that can be called intrajugular lymphatic vessels. CONCLUSIONS: The anatomical features of the DCLNs and their connections with intracranial lymphatic structures through the jugular foramen represent an important possible route for the spread of cancers to and from the central nervous system; therefore, it is essential to have an in-depth understanding of the anatomy of these lymphatic structures and their variations.

The Caudate Nucleus: Its Connections, Surgical Implications, and Related Complications.

BACKGROUND: The caudate nucleus is a C-shaped structure that is located in the center of the brain and is divided into 3 parts: the head, body, and tail. METHODS: We detail the anatomic connections, relationships with other basal ganglia structures, and clinical implications of injury to the caudate nucleus. RESULTS: Anatomically, the most inferior transcapsular gray matter is the lentiform peduncle, which is the connection between the lentiform nucleus and caudate nucleus as well as the amygdala. The border between the tail and body of the caudate nucleus is the posterior insular point. The tail of the caudate nucleus is extraependymal in some parts and intraependymal in some parts of the roof of the temporal horn of the lateral ventricle. The tail of the caudate nucleus crosses the inferior limiting sulcus (temporal stem), and section of the tail during approaches to lesions involving the temporal stem may cause motor apraxia. The mean distance from the temporal limen point, which is the junction of the limen insula and inferior limiting sulcus, to the tail of the caudate nucleus in the temporal stem is 15.87 ± 3.10 mm. CONCLUSIONS: Understanding of the functional anatomy and connections of the distinct parts of the caudate nucleus is essential for deciding the extent of resection of lesions involving the caudate nucleus and the types of deficits that may be found postoperatively.

Robotic Orthogonal Implantation of Responsive Neurostimulation (RNS) Depth Electrodes in the Mesial Temporal Lobe: Case Series.

BACKGROUND: Responsive neurostimulation (RNS) is a closed-loop neurostimulation modality for treating intractable epilepsy in patients who are not candidates for resection. In the past, implantation of depth electrodes was done through a transoccipital approach that transverses the hippocampus. There have been no descriptions of orthogonal approaches to RNS electrode placement. OBJECTIVE: To describe our initial experience with placing RNS depth electrodes using an orthogonal approach to target the short axis of the mesial temporal lobe. METHODS: Presurgical work-up included magnetic resonance imaging, video electroencephalography, and neuropsychological testing. During the procedure, patients were placed with their heads in a neutral position. Electrodes were placed via stereotactic robotic assistance using a unilateral orthogonal approach targeting the amygdala or hippocampus. Patients who underwent RNS electrode implantation via orthogonal approach were identified. Multiple variables were collected, including age, disease onset, complications, follow-up, semiology, and seizure reduction. RESULTS: There were 8 patients who underwent RNS electrode placement with orthogonal approach. The mean age and follow-up were 44.8 and 1.2 yr, respectively. There were 4 patients with at least 1-yr follow-up. Of them, 1 was seizure free and 2 experienced over 50% reduction in seizures. There were no complications associated with electrode implantation. CONCLUSION: The initial experience using an orthogonal approach for depth electrode placement for RNS implantation was described. The potential advantages may include better safety, accuracy, and positioning in comparison to a transoccipital approach.

Cerebral Peduncle Volume and Motor Function Following Adult Hemispherectomy.

BACKGROUND: Hemispherectomy is a successful and well-described treatment option for pediatric patients with hemispheric ictal onset, but adult outcomes have been far less studied. We describe the outcomes in adult patients with medically refractory epilepsy and hemispheric disease and the relationship to cerebral peduncle volume. CASE DESCRIPTIONS: We retrospectively reviewed adult hemispherectomy patients at our institution from 2015 to 2018. Patient data including demographic information, pathologic changes, seizure-free outcomes, and ipsilateral (i.e., surgical side) and contralateral (i.e., functional side) cerebral peduncle volume data were collected. We identified 4 adult patients who underwent hemispherectomy. The mean age at surgery was roughly 25 years. All patients were categorized as Engel I or II, and motor scores at last follow-up were unchanged. The mean volume for contralateral and ipsilateral cerebral peduncle means were 1.42 and 0.78 cm3, respectively (P = 0.01). CONCLUSIONS: These findings suggest that smaller ipsilateral cerebral peduncle size could potentially be associated with unchanged postoperative hemiparesis. We hypothesize that smaller ipsilateral peduncle size could have represented corticospinal tract reorganization in childhood, implying that the removed brain matter was mostly noncontributory to contralateral motor function.

Integrative Medicine as a Vital Component of Patient Care.

The landscape of medicine in the United States has been slowly progressing toward a more holistic and individualized approach to healing. Part of this progress has been the integration between western and alternative forms of medicine, a concept that has been described as "integrative medicine." This approach to healthcare incorporates a patient's mind, spirituality, and sense of community into the healing process. Integrative medicine has been typically well received and the demand has been steadily increasing in primary US hospitals. Here we cover a number of topics that include the definition of integrative medicine, its potential benefits, current examples of successful implementations, and potential barriers to its expansion. The aim was to give a primary on integrative medicine and its current state for healthcare providers.

Falcine Myxoid Chondrosarcoma: A Rare Aggressive Case.

Chondrosarcoma is the second most common primary malignancy of bone after osteosarcoma. Cranial primary chondrosarcomas mostly originate from the skull base cartilage formation zones. Parasagittal falcine origin is very rare for primary extra-skeletal intracranial chondrosarcomas. We report a rare case of primary myxoid chondrosarcoma at falx cerebri. The patient was a 35-year-old lady with right arm and leg weakness. Her brain magnetic resonance imaging depicted a left parasagittal mass lesion attached to the falx cerebri. En bloc resection via left frontal craniotomy was performed. Three more local recurrences occurred in 9 months' time since the index surgery, which were all managed with re-surgeries and/or adjuvant stereotactic radiosurgeries. This is the second case of myxoid type parasagittal chondrosarcoma but with the most protracted disease course. Even though surgery remains the mainstay of treatment for parasagittal chondrosarcomas, adjuvant therapy might be necessary in aggressive ones.

A clinical scoring system to predict the development of intraventricular hemorrhage (IVH) in premature infants.

OBJECTiVE: The aim of this study is to develop a scoring system for the prediction of intraventricular hemorrhage (IVH) in preterm infants in the first 7 days of life. METHODS: A prospective, clinical study was conducted in Bahcesehir University, Medical Park Goztepe Hospital Neonatal Intensive Care Unit, with the enrollment of 144 preterm infants with gestational age between 24 and 34 weeks. All preterms were followed up for IVH after birth until the 4th week of life. The demographic characteristics and clinical risk factors were noted. Risk factors were analyzed. The score was established after logistic regression analysis, considering the impact of each variable on the occurrence of IVH within the first 7 days of life. The IVH scores were further applied prospectively to 89 preterm infants as validation cohort. RESULTS: Low gestational age (GA), low Apgar score, and having bleeding diathesis were the most important risk factors for IVH. According to these risk factors, a scoring system was developed for IVH ranged from 0 to 5. According to the risk ratios (RR) obtained from the logistic regression model, low GA (≤ 28 gestational week), presence of bleeding diathesis within 7 days, and low Apgar score increased the risk of IVH (RR = 3.32 for GA ≤ 28 gestational week, RR = 6.7 for presence of bleeding diathesis in 7th day, RR = 3 for having low Apgar score). The score was validated successfully in 89 infants. The area under ROC curve was 0.85 for derivation cohort and 0.807 for validation cohort. The predictive ability of the IVH score for derivation and validation cohort was calculated. The negative predictive values of a score less than 4 were 96.4 and 59.1%. CONCLUSiON: Concerning IVH-related sequelae which continue to be a major public health problem, we have developed a feasible predictive model for evaluating the risk for developing IVH for preterm infants in the first 7 days of life.

Adding Expansile Duraplasty to Posterior Fossa Decompression May Restore Cervical Range of Motion in Grade 3 Chiari Malformation Type 1 Patients.

BACKGROUND: Few studies have assessed the effect of Chiari malformation type 1 (CM-1) surgical decompression on cervical lordosis and range of motion (ROM). We aimed to assess the effect of expansile duraplasty on postoperative cervical mobility and spinal stability. MATERIALS AND METHODS: This was a single-center retrospective review of prospectively collected data. Patients were included if they underwent surgical treatment for symptomatic CM-1 between the years 1999 and 2009. Cervical ROM and lordosis were assessed before and after surgery in all patients. Collected data also included clinical improvement, as well as surgical complications after the procedure. Patients were divided into 2 groups. The first group underwent a posterior fossa bony decompression alone, while the second group additionally received an expansile duraplasty. Patients were further subdivided into 3 subgroups on the basis of the severity of tonsillar herniation. RESULTS: A total of 76 patients fit our selection criteria. Fifty-five patients belonged to the duraplasty group. Twenty-one patients underwent bony decompression alone. The 2 groups were statistically demographically and clinically similar. There was no difference in clinical outcome or in ROM and cervical lordosis between the groups except for patients with severe tonsillar herniation (CM-I grade 3). These patients had a statistically significant improvement in their postoperative cervical motility without compromising their spinal stability. CONCLUSION: Adding an expansile duraplasty to craniovertebral decompression in CM-1 patients with severe tonsillar herniation may restore cervical ROM while preserving stability and alignment. This may relieve postoperative pain and improve clinical prognosis.

A Very Quickly Prepared, Colored Silicone Material for Injecting into Cerebral Vasculature for Anatomical Dissection: A Novel and Suitable Material for both Fresh and Non-Fresh Cadavers.

AIM: Cadaveric studies have a great impact on neuroanatomy learning. Cadaver preparation may take a lot of effort, especially at the phase of intravascular color filling. The authors describe their silicone dye technique and a novel mixture which is self-curing, quick to prepare and easy to inject. MATERIAL AND METHODS: The first one of these processes is undoubtedly embalming and decapitation of the cadaver. If possible, the most appropriate time that should be preferred is immediately after the donor's death. Preparation for cadaveric dissection of the brain requires some fundamental steps that can be summarized into: a) Embalming and decapitation, b) Exposing, cannulization and irrigation of main vascular structures, c) Preparing colored silicone, d) Injection of colored silicone and staining the vascular tree, e) Sample maintenance RESULTS: Our method of preparation of silicone dye and injection enables neurosurgeons and anatomists to fill cerebral and dural vascular structures, and even diploic veins nicely in both fresh and aged cadaveric heads. Moreover, the main vascular structures and their branches in the lateral and third ventricles are painted remarkably beautifully. CONCLUSION: We tried to provide our experience about the preparation of head cadavers for anatomical dissection using a novel mixture of colored silicone that is very easy to prepare and inject with very satisfactory results.

Craniospinal Polyostotic Fibrous Dysplasia, Aneurysmal Bone Cysts, and Chiari Type 1 Malformation Coexistence in a Patient with McCune-Albright Syndrome.

Aneurysmal bone cysts (ABCs) are defined as benign cystic lesions of bone composed of blood-filled spaces. ABCs may be a secondary pathology superimposed on fibrous dysplasia (FD). Concomitant FD and ABC in relation with McCune-Albright syndrome is an extremely rare condition. Here, we report concomitant, double ABCs in bilateral occipital regions and FD from the skull base to the C2 vertebra with Chiari type 1 malformation. A 14-year-old female with a diagnosis of McCune-Albright syndrome presented with swellings at the back of her head. The lesions were consistent with ABCs and were totally resected with reconstruction of the calvarial defects. The coexistence of FD, bilateral occipital ABCs, and Chiari malformation type 1 in a McCune-Albright patient is an extremely rare condition and, to our knowledge, has not been reported to date. Exact diagnosis and appropriate surgical treatment usually lead to a good outcome.

Bubble over the head: Adeloye-Odeku disease in a Turkish child-case report.

Adeloye-Odeku disease is composed of dermoid cyst over anterior fontanelle, first described in 1971. We present an 11-year-old girl with a soft, fluctuant swelling over bregma. The lesion content was isointense to cerebrospinal fluid on both T2W and FLAIRW images. There was a lytic area under the lesion, seen on CT. The lesion was totally excised. Histopathology confirmed the diagnosis. The case was unique; because a fibrous band was observed extending to superior sagittal sinus and it has never been reported before. Although lesions are sub-aponeurotic, because of this kind of fibrous band, a thorough examination with neuroimaging tools is very important for planning of surgery.

Rare and challenging extra-axial brain lesions: CT and MRI findings with clinico-radiological differential diagnosis and pathological correlation.

There are many kinds of extra-axial brain tumors and tumor-like lesions, and definitive diagnosis is complicated in some cases. In this pictorial essay, we present rare and challenging extra-axial brain lesions including neuroenteric cyst, primary leptomeningeal melanomatosis, isolated dural neurosarcoidosis, intradiploic epidermoid cyst, ruptured dermoid cyst, intraventricular cavernoma, and cavernous hemangioma of the skull with imaging findings and clinico-radiological differential diagnosis, including the pathologic correlation. Familiarity with these entities may improve diagnostic accuracy and patient management.

Neuroendoscopic management of suprasellar arachnoid cysts.

BACKGROUND: The first case of an intracranial arachnoid cyst was described by Bright in 1831. In 1935, Barlow published the first case of a suprasellar arachnoid cyst. Fewer than 200 cases of suprasellar-prepontine arachnoid cysts have been reported in the literature as of January 2011. METHODS: Between 1994 and 2010, the senior author operated on 34 cases of suprasellar-prepontine arachnoid cysts. Eighteen female and 16 male patients ranged in age from 6 days to 16 years (mean 5.2 years). Follow-up of the patients ranged from 1 year to 16 years. RESULTS: Outcome may be evaluated according to radiological and clinical follow-up data. Postoperative radiological examinations must reveal: 1) the adequacy of fenestrations and flow through fenestration sites, 2) reduction of the cyst and ventricle size, and 3) reorientation of the chiasma and mammillary bodies to an acceptable anatomical position. In our series, no mortality occurred. Postoperative complication occurred in 3 cases. CONCLUSIONS: Suprasellar arachnoid cysts can be treated with favorable clinical and radiological results with endoscopic interventions when feasible. Results with ventriculocystocisternostomy are believed superior to those of ventriculocystostomy.