Simplified supine modified park bench / lateral decubitus position using a shoulder pad and a Mayfield head clamp for neurosurgical approach to lesions located in the occipital lobe or the posterior fossa: technical note.

Neurosurgical approach to lesions located in the occipital lobes or in the posterior fossa require very specific and time-consuming patient installations, such as the park bench position, the prone position, or the sitting position. Nevertheless, each of these position present major drawbacks regarding specific installation-related adverse events and potentially serious neurosurgical complications such as venous air embolism, iatrogenic intracranial hypertension, and supratentorial remote hematoma just to cite a few. In order to provide neurosurgeons with a simpler, physiologically-respective, easily tolerated, less time-consuming, and less provider or specific adverse events patient installation, Ochiai (1979) introduced the supine modified park-bench / lateral decubitus position. Given that this patient position has not gained wide visibility among the neurosurgical community despite its obvious numerous advantages over its classic counterparts, we provide our experience using this installation for neurosurgical approach to lesions located in the occipital lobes and in the posterior fossa.

Soft tissue Reconstruction Using Pedicled Trapezius Musculocutaneous Flap for Cranial Bone Flap Infection in the Occipital Region.

When managing cranial bone flap infections, infected bone flaps are typically removed and subsequently replaced with artificial bones 6 to 12 months after the inflammation subsides. However, defects in the occipital region pose challenges due to concerns regarding brain protection when patients lie in the supine position. Herein, the authors report the case of a 73-year-old woman with an occipital bone flap infection, which was successfully managed by reconstruction with a trapezius musculocutaneous flap immediately after removing the infected bone flap. One year and 2 months postoperatively, the wound had fully healed, and the patient remained symptom-free without any complications, such as sunken flap syndrome. Soft tissue reconstruction using pedicled trapezius musculocutaneous flap is a viable strategy for managing occipital bone flap infections. This flap ensures stable blood flow and requires minimal vascular manipulation, thereby reducing operation time as the patient does not need to change position.

The sub-occipital transtentorial approach for pineal region tumors: how I do it.

BACKGROUND: Two major approaches exist for the surgical removal of pineal region tumors: the supracebellar infratentorial and the sub-occipital transtentorial. METHODS: We present the Lyon's technique of the sub-occipital transtentorial approach for pineal region tumors and our tricks to avoid complications. The principle is to expose the pineal region under the occipital lobe and not through the interhemispheric fissure. CONCLUSIONS: The sub-occipital transtentorial approach is a direct, extra cerebral, safe, and effective way to access tumors of the pineal region.

The posterior interhemispheric transparieto-occipital fissure approach to the atrium of the lateral ventricle: a fiber microdissection study with case series.

The surgical approach to the atrium of the lateral ventricle remains a challenge because of its deep location and close relationship to important neurovascular structures. We present an alternative and safer approach to lesions of the atrium using a natural pathway through the parieto-occipital fissure. We demonstrate this approach through cadaveric anatomical microdissection and a case series. Five formalin-fixed brain specimens (10 hemispheres) were dissected with the Klingler technique. Transillumination was used to show the trajectory of the approach in cadaveric specimens. Clinical data from five patients who underwent this approach were reviewed. This data included intraoperative ultrasound images, operative images, pre- and postoperative magnetic resonance imaging, MR tractography, and visual field examination. The parieto-occipital fissure is a constant, uninterrupted fissure that can be easily identified in cadavers. Our anatomical dissection study revealed that the atrium of the lateral ventricle can be approached through the parieto-occipital fissure with minor damage to the short association fibers between the precuneus and cuneus, and a few fibers of the forceps major. In our series, five patients underwent total resection of their atrial lesions via the posterior interhemispheric transparieto-occipital fissure. No morbidity or mortality was observed, and the disruption of white matter was minimal, as indicated on postoperative tractography. The postoperative visual fields were normal. The posterior interhemispheric transparieto-occipital fissure approach is an alternative to remove lesions in the atrium of the lateral ventricle, causing the least damage to white matter tracts and preserving visual cortex and optic radiation.

[Modified posterior quadrant disconnection in surgical treatment of drug-resistant epilepsy in a patient with left temporal and occipital lobe malformation]. / Modifitsirovannaya zadnekvadrantnaya diskonnektsiya v khirurgicheskom lechenii farmakorezistentnoi epilepsii u patsienta s porokom razvitiya levykh visochnoi i zatylochnoi dolei.

Adults with large multilobar lesions of temporal, parietal and occipital lobes of the dominant hemisphere suffering from drug-resistant epilepsy were considered inoperable for a long time. OBJECTIVE: To demonstrate favorable postoperative outcome in a patient with massive periventricular heterotopia of the left temporal and occipital lobes complicated by drug-resistant epilepsy. MATERIAL AND METHODS: We analyzed localization of the brain malformation (massive periventricular heterotopia) and its relationship with surrounding structures in a 38-year-old patient considering preoperative MRI, functional MRI and MR tractography data. Quality of modified posterior quadrant disconnection was assessed within a day and 6 months after surgery in accordance with MRI data. Transcranial stimulation, direct cortical and subcortical monopolar stimulation were used for intraoperative monitoring of corticospinal tract. We also assessed neurological status and linguistic testing data before surgery, 4 days and 6 months after surgery. RESULTS: Modified posterior disconnection of temporal, parietal and occipital lobes was performed. Intraoperative neurophysiological cortical mapping (asleep-awake-sedation protocol) verified localization of Wernicke's area. There was an expected right-sided homonymous hemianopsia in postoperative period without speech disorders. Postoperative outcome Engel grade 1A under anticonvulsant therapy was obtained. CONCLUSION: The authors report successful surgical treatment of massive malformation of the left temporal, parietal and occipital lobes and literature review devoted to this issue.

Parietal interhemispheric transfalcine transtentorial approach for posterior incisural space lesions: from the lab to the operative room.

The operative approach to the posterior incisural space is challenging because of its deep location, the surrounding eloquent areas, and the intimate relationship with the deep veins. Several approaches have been proposed to manage the lesions in this region: supratentorial, infratentorial and a combination of them. Brain retraction, injury to the occipital lobe and corpus callosum, and venous bleeding are the principle drawbacks of these routes. We performed anatomical dissection study using 10 embalmed human cadaver specimens injected with colored latex exploring a different route, parietal interhemispheric transfalcine transtentorial (PITT). Then we used a PITT approach on two patients with posterior incisural space (PIS) lesions. The PITT approach led to successful and safe complete removal of PIS lesions in our cases. No complications were reported. The present approach could be a valuable option in case of PIS lesions, especially those associated with downward displacement of the deep venous complex; thanks to the gravity it reduce the complications related to the occipital lobe retraction and manipulation. Moreover, cutting the superior-anterior edge of the tentorium, the sub-tentorial space could be reached.

Visual field restoration after Simpson grade I resection of symptomatic occipital lobe meningioma: illustrative case and review of the literature.

Intracranial meningiomas mostly affect patients in their fifth decade and beyond, raising pertinent questions regarding the risk of surgery, particularly in the elderly. Here, we describe the case of a septuagenarian patient with occipital meningioma causing severe visual field cuts that experienced full recovery of the visual function after a Simpson I resection of the lesion. This case illustrates the potential of recovery of the brain, even in the case of severely impaired function in elderly patients. To complete the picture, we review the literature on occipital meningiomas, advocating for systematic reports and increase data collection on post-operative neurological recovery in the elderly.

Stereotactic MRI-guided laser interstitial thermal therapy for extratemporal lobe epilepsy.

OBJECTIVE: Magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (MRg-LITT) is an alternative to open epilepsy surgery. We assess safety and effectiveness of MRg-LITT for extratemporal lobe epilepsy (ETLE) in patients who are considered less favorable for open resection. METHODS: We retrospectively reviewed sequential cases of patients with focal ETLE who underwent MRg-LITT between 2012 and 2019. Epileptogenic zones were determined from standard clinical and imaging data ± stereoelectroencephalography (SEEG). Standard stereotactic techniques, MRI thermometry, and a commercial laser thermal therapy system were used for ablations. Anatomic MRI was used to calculate ablation volumes. Clinical outcomes were determined longitudinally. RESULTS: Thirty-five patients with mean epilepsy duration of 21.3 ± 12.2 years underwent MRg-LITT for focal ETLE at a mean age 36.4 ± 12.7 years. A mean 2.59 ± 1.45 trajectories per patient were used to obtain ablation volumes of 8.8 ± 7.5 cm3 . Mean follow-up was 27.3 ± 19.5 months. Of 32 patients with >12 months of follow-up, 17 (53%) achieved good outcomes (Engel class I + II) of whom 14 (44%) were Engel class I. Subgroup analysis revealed better outcomes for patients with lesional ETLE than for those who were nonlesional, multifocal, or who had failed prior interventions (P = .02). Of 13 patients showing favorable seizure-onset patterns (localized low voltage fast activity or rhythmic spiking on SEEG) prior to ablation, 9 (69%) achieved good outcomes, whereas only 3 of 11 (27%) who show other slower onset patterns achieved good outcomes. Minor adverse events included six patients with transient sensorimotor neurologic deficits and four patients with asymptomatic hemorrhages along the fiber tract. Major adverse events included one patient with a brain abscess that required stereotactic drainage and one patient with persistent hypothalamic obesity. Three deaths-two seizure-associated and one suicide-were unrelated to surgical procedures. SIGNIFICANCE: MRI-guided laser interstitial thermal therapy (or MRg-LITT) was well-tolerated and yielded good outcomes in a heterogeneous group of ETLE patients. Lesional epilepsy and favorable seizure-onset patterns on SEEG predicted higher likelihoods of success.

Rotation Flaps in Series: Simple Innovation for Complex Scalp Defects.

A 42-year-old man presented with 2 full thickness defects in left parieto-temporal and right temporo-occipital regions with normal intervening scalp tissue. These 2 adjacent but discontinuous defects were covered in one stage with an innovative rotation flap design that provided 1 flap each for these 2 defects. This innovative flap design permitted one stage reconstruction with primary closure of the donor sites.

Clinical Characteristics and Surgical Features of Intracranial Fibrosarcoma.

BACKGROUND: Intracranial fibrosarcoma is an extremely rare neoplasm in the central nervous system. Insofar there were only sporadic case reports describing its features. The purpose of this study is to review the clinical and surgical features of cases who were treated in our department. METHOD: The authors retrospectively reviewed and detailed the clinical and surgical data obtained from 5 patients with fibrosarcoma who underwent treatment at our institute between January 2009 and January 2019. RESULTS: There were 3 males and 2 females including 2 juvenile and 3 senior patients. The most frequent sign was intermittent pain and vomiting. The location of the tumor included middle fossa, thalamus and midbrain, sellar and suprasellar region and right parietal-occipital lobe. Surgical observation demonstrated the consistency of the tumor was tenacious with abundant blood supply. Gross total resection was achieved in 2 cases. Pathological analysis showed spindle cells in a herringbone form with positive Vimentin staining in all 5 cases, with the absence of GFAP or S-100. All 5 patients were deceased eventually after a varied period of time after the first surgery. CONCLUSION: Intracranial fibrosarcoma was a highly malignant entity presented in the central nervous system. Surgery still remains the first-line treatment followed by radiotherapy, however, the prognostic outcome was very poor. Future studies should be more focused on accumulation of the relevant information on this disease thus hopefully in assisting to developing more optimized treatment.

Tracking patients with chronic occipital headache after occipital nerve decompression surgery: A case series.

BACKGROUND: The therapeutic benefit of nerve decompression surgeries for chronic headache/migraine are controversial. AIM: To provide clinical characteristics of headache type and treatment outcome of occipital nerve decompression surgery. METHODS: A retrospective review of clinical records. Inclusion criteria were evidence of chronic occipital headache with and without migrainous features and tenderness of neck muscles, occipital allodynia, and inadequate response to prophylactic drugs. RESULTS: Surgical decompression of the greater and lesser occipital nerves provided complete and extended (3-6 years) relief of new daily persistent headache in case 3 (46 year old female), and of chronic post-traumatic headache in cases 4 and 6 (35 and 30 year old females, respectively), partial relief of chronic headache/migraine in cases 1 and 2 (41 year old female and 36 year old male), and no relief of episodic (cases 3 and 4) or chronic migraine (case 5, 52 year old male), or chronic tension-type headache (case 7, 31 year old male). CONCLUSIONS: As a case series, this study cannot test a hypothesis or determine cause and effect. However, the complete elimination of new daily persistent headache and post-traumatic headache, and the partial elimination of chronic headache/migraine in two patients - all refractory to other treatment approaches - supports and justifies the effort to continue to generate data that can help determine whether decompression nerve surgeries are beneficial in the treatment of certain types of chronic headache.

The segmentation of the posterior cerebral artery: a microsurgical anatomic study.

There are still different descriptions of the segmentation of the posterior cerebral artery, although there is a radiological and anatomical consensus on the segmentation of the anterior and the middle cerebral artery. This study aims to define the most appropriate localization for origin and end points of the segments through reviewing the segmentation of the posterior cerebral artery. The segments and the cortical branches originating from those segments of the 40 posterior cerebral arteries of 20 cadaver brains were examined under operating microscope. In this research, the P1, P2, P3, P4, and P5 classification of the segmentation of the posterior cerebral artery is redefined. This redefinition was made to overcome the complexities of previous definitions. The P1 segment in this research takes its origin from the basilar tip and ends at the junction with the posterior communicating artery. The average diameter of this segment at the origin was 2.21 mm (0.9-3.3), and the average length was 6.8 mm (3-12). The P2 segment extends from the junction with the posterior communicating artery to the origin of the lateral temporal trunk. This point usually situates on one level of posterior of the cerebral peduncle. The average diameter of this segment at the origin was 2.32 mm (1.3-3.1), and the average length was 20.1 mm (11-26). The P3 segment extends from the origin of the lateral temporal trunk to the colliculus where both the posterior cerebral arteries are the nearest to each other (quadrigeminal point) and is located at the anterior-inferior of the splenium. The average diameter of this segment at the origin was 1.85 mm (1.2-2.7), and the average length was 16.39 mm (9-28). The P4 begins at the quadrigeminal point and ends at the top of the cuneus. The average diameter of this segment at the origin was 1.55 mm (1.1-2.2). While the P5 segment is named as the terminal branches of the major terminal branches of the posterior cerebral artery, no definite border was found between the P4 and the P5 segments. In this study, the segmentation of the posterior cerebral artery, developed by Krayenbühl and Yasargil, was redefined to be more appropriate for radiological and anatomical purposes.

Surgical "Safe Zone": Rapid Anatomical Identification of the Lesser Occipital Nerve.

BACKGROUND: Surgical intervention has established a vital role in the management of chronic headaches. The lesser occipital nerve (LON) is a common target in patients suffering from occipital neuralgia and is often resected as a first-line option. We endeavored to define the relationships of the LON in the posterolateral neck to facilitate its safe and rapid intraoperative identification. METHODS: Seven fresh cadavers (14 nerves) were dissected, and their relationships to the mastoid prominence and nearby spinal accessory nerve (SAN) and greater auricular nerve were noted. RESULTS: The distance from the mastoid to the emergence of the LON along the posterior sternocleidomastoid ranged from 36 to 51 mm (mean: 45.2 mm), with relative symmetry between the two nerves in the same cadaver. The SAN emerged an average of 54 mm from the mastoid prominence. CONCLUSION: Exploration for the LON should begin at a point 40 mm from the mastoid prominence along the posterior border of the sternocleidomastoid muscle. If the point of exit of the LON is not identified within 10 mm of this exposure, our dissection continues cranially along the posterior border of the sternocleidomastoid, anterior to the trapezius. In rare cases the nerve may pierce the fibers of the muscle and ascend directly on top of the muscle belly. By limiting the caudal extend of the dissection, we can avoid exposure of the SAN and minimize the risk of iatrogenic nerve injury.

Multistaged, multidirectional strategy for safe removal of large meningiomas in the pineal region.

OBJECTIVE Pineal region meningiomas are rare and tend to be discovered only after they grow. Several simultaneous multidirectional approaches performed as a single operation have been proposed, but the best strategy to remove these deeply situated large meningiomas involving the deep vital venous system remains to be established. The authors advocate a multistaged, multidirectional approach to safely remove these challenging tumors. METHODS Four consecutive cases of meningioma in the pineal region were treated between April 2013 and June 2016. The 3 large (> 40 mm diameter) tumors were removed via multistaged, multidirectional approaches (2 surgeries in 2 patients and 3 surgeries in 1 patient) with gravity retraction of the occipital or parietal lobe. The large occipital skin incision extending bilaterally was used for the next operation from the contralateral side. Combinations of the occipital transtentorial approach with or without the transfalcine approach, occipital bitranstentorial/falcine approach, combined supra-/infratentorial transsinus approach, and contralateral parietal interhemispheric transcallosal approach were used. RESULTS Transient visual field deficits occurred after 2 of the 8 operations, but all tumors were removed grossly or subtotally without permanent surgery-related morbidity. The galenic venous system and straight sinus remained intact in all patients. During the follow-up period (mean 29.5 months [range 13-52 months]), there were no recurrences after the final operation. CONCLUSIONS A multistaged, multidirectional strategy with an intentional large occipital scalp incision and gravity retraction of the occipital lobe is a good choice for the safe removal of large meningiomas in the pineal region.

A distinct clinicopathological variant of focal cortical dysplasia IIId characterized by loss of layer 4 in the occipital lobe in 12 children with remote hypoxic-ischemic injury.

OBJECTIVE: In 2011, the International League Against Epilepsy (ILAE) proposed a consensus classification system of focal cortical dysplasia (FCD) to distinguish clinicopathological subtypes, for example, "isolated" FCD type Ia-c and IIa-b, versus "associated" FCD type IIIa-d. The histopathological differentiation of FCD type I and III variants remains, however, a challenging issue in everyday practice. We present a unique histopathological pattern in patients with difficult-to-diagnose FCD, which highlights this dilemma, but also helps to refine the current ILAE classification scheme of FCD. METHODS: We present a retrospective series of 11 male and one female patient with early onset pharmacoresistant epilepsy of the posterior quadrant (mean age at seizure onset = 4.6 years). All surgical specimens were reviewed. Clinical histories were retrieved and extracted from archival patient files. RESULTS: Microscopic inspection revealed abnormalities in cortical architecture with complete loss of layer 4 in all surgical samples of the occipital lobe, as confirmed by semiquantitative measurements (p < 0.01). Clinical history reported early transient hypoxic condition in nine patients (75%). Magnetic resonance imaging (MRI) revealed abnormal signals in the occipital lobe in all patients, and signal changes suggestive of subcortical encephalomalacia were found in seven patients. Surgical treatment achieved favorable seizure control (Engel class I and II) in seven patients with an available follow-up period of 6.1 years. SIGNIFICANCE: Prominent disorganization of cortical layering and lack of any other microscopically visible principle lesion in the surgical specimen would result in this neuropathological pattern hitherto being classified as FCD ILAE type Ib. However, perinatal hypoxia with distinctive MRI changes suggested primarily a hypoxemic lesion and acquired pathomechanism of neuronal cell loss in the occipital lobe of our patient series. We propose, therefore, classifying this distinctive clinicopathological pattern as a separate variant of FCD ILAE type IIId.

Adult-onset atypical teratoid/rhabdoid tumor featuring long spindle cells with nuclear palisading and perivascular pseudorosettes.

Atypical teratoid/rhabdoid tumors (AT/RTs) are rare malignant neoplasms of the CNS that preferentially affect young children. We herein report an adult case of AT/RT surviving for more than 5 years with the residual tumor. The patient, a 24-year-old man at onset, presented with a contrast-enhancing mass lesion in the left occipital lobe, and underwent partial tumor resection. Histologically, the tumor was predominantly composed of long spindle cells exhibiting nuclear palisading and perivascular pseudorosettes, which appeared to mimic mesenchymal, ependymal and Schwann cell tumors. A small number of isolated rhabdoid cells did not initially attract attention, and a tentative pathological diagnosis of a malignant mesenchymal tumor was made. In a later examination focusing on the small areas of rhabdoid cells, the extensive loss of the nuclear expression of INI1 was detected in all areas. Diffuse staining with vimentin and focal immunoreactivity for epithelial membrane antigen and alpha smooth muscle actin were observed not only in AT/RT foci, but also in spindle cell areas. Thus, polyphenotypic immunoreactivity was evident. Fluorescence in situ hybridization revealed a homozygous deletion of chromosome 22q covering the INI1 locus. Histopathological differences between infant and adult AT/RTs currently remain unclear. In the case of a malignant adult brain tumor showing a hardly classifiable morphology and immunophenotypic diversity, an analysis of the INI1 status may contribute to an accurate diagnosis.

Resection of complex occipital arteriovenous malformation with giant varix: demonstration of microsurgical technique.

The complexity of arteriovenous malformations (AVMs) does not necessarily preclude surgical resection. In this video the authors present a 72-year-old male who was known to have an occipital AVM with a large draining varix for the previous 10 years. The patient had progressively worsening visual and cognitive deficits over several years. Total surgical resection was achieved following single stage preoperative embolization. Although resection of the AVMs is challenging, even in experienced hands, it offers a cure and may improve patient clinical outcome. The video can be found here: https://youtu.be/YI1AwGjJdvo .

Microsurgical resection of a high-grade occipital arteriovenous malformation after staged embolization.

The authors demonstrate the case of a 16-year-old girl with a large symptomatic occipital arteriovenous malformation (AVM). The staged embolization was performed to downgrade the AVM from Spetzler-Martin (S-M) Grade IV (Supplementary S-M Grade 7) to Grade III (Supplementary S-M Grade 5). The patient developed a subacute progressive visual field defect after the final time of embolization. MRI revealed an enlarged draining venous ectasia of the AVM compressing the visual cortex. Postoperatively, good radiological results were achieved, and the patient reported an improvement in her symptoms. The detailed operative technique and surgical nuances (including the surgical features of the AVM postembolization) of the marginal dissection and removal are illustrated in this video atlas. The video can be found here: https://youtu.be/2MZq5patcJI .

Occipital and occipital "plus" epilepsies: A study of involved epileptogenic networks through SEEG quantification.

Compared with temporal or frontal lobe epilepsies, the occipital lobe epilepsies (OLE) remain poorly characterized. In this study, we aimed at classifying the ictal networks involving OLE and investigated clinical features of the OLE network subtypes. We studied 194 seizures from 29 consecutive patients presenting with OLE and investigated by stereoelectroencephalography (SEEG). Epileptogenicity of occipital and extraoccipital regions was quantified according to the 'epileptogenicity index' (EI) method. We found that 79% of patients showed widespread epileptogenic zone organization, involving parietal or temporal regions in addition to the occipital lobe. Two main groups of epileptogenic zone organization within occipital lobe seizures were identified: a pure occipital group and an occipital "plus" group, the latter including two further subgroups, occipitotemporal and occipitoparietal. In 29% of patients, the epileptogenic zone was found to have a bilateral organization. The most epileptogenic structure was the fusiform gyrus (mean EI: 0.53). Surgery was proposed in 18/29 patients, leading to seizure freedom in 55% (Engel Class I). Results suggest that, in patient candidates for surgery, the majority of cases are characterized by complex organization of the EZ, corresponding to the occipital plus group.

A case of cephalomelia discovered in a baby born in Niger.

INTRODUCTION: Subcutaneous tumors with extra limbs are very rare, and they are considered either as fetus in fetu or fetiform teratoma. CASE REPORT: We report here the case of a 6-day-old presenting a mass extending at the level of the occipital bone. This mass is developed in the extracranial region and contains two forelimbs including hands with digits. CT shows that the squamous part of the occipital bone is involved with several defects through which a part of the cerebellum herniates. The boy was operated on and the tumor was removed. The herniated region of the cerebellum has also been removed. After surgery, the boy develops normally. CONCLUSION: This type of tumor is extremely rare and is only the second case that has been reported at this exact location. This could be the so-called céphalomélie described by Isidore Geoffroy Saint-Hilaire in a duck in his famous Treatise of Teratology (1836). The cause of this malformation is still a matter for debate.