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Journal: Journal of neurological surgery. Part A, Central European neurosurgery

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The number of lesions of the skull base currently resected via endoscopic, endonasal, transphenoidal approach has increased. We have successfully treated 63 consecutive patients with pituitary lesions using this technique in combination with BrainLAB reference headband and laser surface scanning (BrainLAB®, Heimstetten, Germany) for surgical navigation. This technique affords several advantages over neuronavigation based on adhesive-mounted fiducial registration. Rigid fixation in a Mayfield clamp is not required, which allows for flexibility with respect to positioning of the head during the procedure. This is particularly important, as extension and flexion of the head provide greater exposure to the clivus and anterior skull base, respectively. Also, we demonstrate that this technique is safe, easy-to-use, and faster compared with other ones.

Concepts: Head and neck anatomy, Surgery, Skull, Knee, Neurosurgery, Extension, Skull and Bones, Fiduciary marker

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Background and Study Aims/Object Oral nimodipine is recommended to reduce poor outcome related to aneurysmal subarachnoid hemorrhage (SAH). In addition, animal experiments and clinical trails revealed a beneficial effect of enteral and parenteral nimodipine for the regeneration of cranial nerves following skull base, laryngeal, and maxillofacial surgery. Despite these findings there is a lack of pharmacokinetic data in the literature, especially concerning its distribution in nerve tissue.Patients/Material and Methods Samples were taken from a consecutive series of 57 patients suffering from skull base lesions and treated with nimodipine prophylaxis from the day before surgery until the seventh postoperative day. Both groups received standard dosages for enteral (n = 25) and parenteral (n = 32) nimodipine . Nimodipine levels were measured in serum, cerebrospinal fluid (CSF), and tissue samples, including vestibular nerves.Results Nimodipine levels were significantly higher following parenteral as compared with enteral administration for intraoperative serum (p < 0.001), intraoperative CSF (p < 0.001), tumor tissues (p = 0.01), and postoperative serum (p < 0.001). In addition, nimodipine was significantly more frequently detected in nerve tissue following parenteral administration (Fisher's exact test, p = 0.015).Conclusions From a pharmacokinetic point of view, parenteral nimodipine medication leads to higher levels in serum and CSF. Furthermore, traces are more frequently found in nerve tissue following parenteral as compared with enteral nimodipine administration, at least in the early course.

Concepts: Cranial nerves, Subarachnoid hemorrhage, Cerebrospinal fluid, Route of administration, Nerve, Fisher's exact test, Exact test, Routes of administration

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Objective The accessory nerve has cranial and spinal roots. The cranial roots emerge from the medulla, whereas the spinal roots arise from motor cells within the ventral horn of C1-C7 segments of the spinal cord. Communications have been described between the spinal accessory nerve rootlets and the dorsal rootlets of cervical spinal nerves. In the present case, we report a communication that has not been reported before and discuss the functional anatomy.Materials and Methods During the dissection of the craniovertebral junction of a 67-year-old formalin-fixed adult male cadaver, a connection between the spinal accessory nerve rootlets and the dorsal rootlets of the cervical spinal nerves was observed.Results A communication between the spinal rootlets of the accessory nerve and the dorsal roots of cervical spinal nerves was present on the right and left side. On the right, a communication between the accessory nerve spinal rootlet and the dorsal rootlet of the fourth cervical spinal nerve existed. On the left, there were two branches from the lowest accessory nerve spinal rootlet, one run ventrally and the other dorsally to the spinal rootlet and reached the dorsal root of third cervical spinal nerve. The dorsal root of C1 did not exist on either the right or the left side. Further, an unusual spinal accessory nerve formation was also observed.Discussion This case does not fit into any of the previously described classifications in the literature. Therefore, the different variations concerning the communications between the spinal rootlets of the accessory nerve and the cervical spinal nerves should be kept in mind during both surgical, especially radical neck dissections, and nonsurgical evaluations.

Concepts: Cranial nerves, Nerve, Spinal nerve, Accessory nerve

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Background Minimally invasive techniques in spine surgery have gained significant popularity due to decreased tissue dissection and destruction, postoperative pain, and hospital stay. The laparoscopic anterior lumbar interbody fusion (ALIF), an innovation in minimally invasive spine surgery, is rarely done because it has marginal benefit over the mini-open ALIF technique in rates of retrograde ejaculation and vascular complications. We propose these outcomes can be improved with enhanced robotic-assisted dissection and exposure for ALIF. Patients Two patients with single-level degenerative spine disease at L5-S1, associated with mechanical back pain, underwent anterior spinal exposure using the da Vinci S Surgical Robot during ALIF. Results In this report, we provide the first description of the use of a surgical robot in the dissection and exposure for ALIF in patients with degenerative spine disease. We demonstrate successful use of the da Vinci Surgical Robot in separating the presacral nervous plexus from retroperitoneal structures without postoperative vascular or urological complications over a 1-year follow-up period. Conclusion Use of the robotic assistance in the performance of ALIF is possible without significant operative complications. This technique may provide added benefit over conventional laparoscopic approaches to the spine.

Concepts: Hospital, Surgery, Minimally invasive, Degenerative disc disease, Orgasm, Robotic surgery, The Da Vinci Code, Da Vinci Surgical System

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Objectives The central location and complex neurovascular structures of the posterior cranial fossa make tumor resection in this region challenging. The traditional surgical approach is a suboccipital craniotomy using a microscope for visualization. This approach necessitates a large surgical window and cerebellar retraction, which can result in patient morbidity. With the advances in endoscopic technology, minimally invasive access to the cerebellopontine angle can be achieved with minimal manipulation of uninvolved structures, reducing the complications associated with the suboccipital approach.Methods An endoscopic and microscopic approach was completed on anatomic specimens. To access the central structures of the posterior cranial fossa, a retrosigmoidal approach was undertaken. A keyhole craniotomy was made in the occipital bone posterior to the junction of the transverse and sigmoid sinuses. The endoscope was advanced and photographs were obtained for review. The exposure was compared with that obtained with a microscope.Results The endoscopic retrosigmoidal approach to the posterior cranial fossa provided increased exposure to the midline structures while minimizing the surgical window. The relevant anatomy was identified without difficulty.Conclusion An endoscopic retrosigmoidal approach to the midline structures of the posterior cranial fossa is anatomically feasible. The morbidity associated with retraction of the cerebellum could possibly be avoided, improving patient outcomes. Retrosigmoidal endoscopy provides access to anatomical structures that is not possible using a microscope in a suboccipital approach. Further understanding of the endoscopic anatomy of the posterior fossa can allow for advances in cranial base surgery with improved safety and efficacy.

Concepts: Medicine, Biology, Physician, Anatomy, Human anatomy, Endoscopy, Posterior cranial fossa, Superficial anatomy

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Objective Motor cortex stimulation (MCS) is an alternative treatment modality for central neuropathic pain, if conservative treatment failed. Study aim was outcome assessment after MCS. Material and Methods This study is a retrospective case series review of patients who had undergone MCS for central pain (n = 8), deafferentation pain (n = 3) and neuropathic trigeminal pain (n = 9) between April 2001 and May 2011. In all patients, four contact-paddle electrodes were placed in the epidural space overlying the motor cortex via burr hole trepanation under local anesthesia. The follow-up period was 6 months to 6 years. Pain control was assessed by the visual analog scale (VAS). Results A total of 22 patients (11 men, 11 women) were treated; after trial stimulation two male patients were excluded for incompliance reasons. The mean patient age was 59.8 years (range: 31-79 years). In the central pain group, three patients reported complete, and four patients satisfactory pain control. In the trigeminal neuropathic pain group, seven patients reported complete, and two patients satisfactory pain control. In the deafferentation pain group, one patient reported complete, and two patients satisfactory pain control. None of the patients showed new neurologic deficits after the MCS. Conclusions MCS is an effective treatment modality for central neuropathic pain and trigeminal pain with low morbidity and mortality. Future studies are necessary to evaluate and optimize this treatment option in more detail.

Concepts: Patient, Hospital, Retrospective, Anesthesia, Local anesthesia, Pain, The Central, Neuropathic pain

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We report a misinterpretation of bilateral mydriasis as blown pupils related to elevated intracranial pressure (ICP) under volatile sedation with isoflurane (Anesthetic Conserving Device [AnaConDa], Hudson RCI, Uppland Vasby, Sweden) in a 59-year-old patient with a severe traumatic brain injury with frontal contusion. The patient showed bilateral mydriasis and a missing light reflex 8 hours after changing sedation from intravenous treatment with midazolam and esketamine to volatile administration of isoflurane. Because cranial computed tomography ruled out signs of cerebral herniation, we assumed the bilateral mydriasis was caused by isoflurane and reduced the isoflurane supply. Upon this reduction the mydriasis regressed, suggesting the observed mydriasis was related to an overdose of isoflurane. Intensivists should be aware of the reported phenomenon to avoid unnecessary diagnostic investigations that might harm the patient. We recommend careful control of the isoflurane dose when fixed and dilated pupils appear in patients without other signs of elevated ICP.

Concepts: Patient, Traumatic brain injury, Intracranial pressure, Pupil, Brain herniation, Mydriasis, Miosis

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 Over the past few years bipolar electrocoagulation techniques in neurosurgery have been continually improving. However, limited access during endoscopic endonasal transsphenoidal surgery (EETS) for central skull base pathologies and the requirement of very precise coagulation in that dedicated anatomical area requires further refinement of bipolar coagulation instruments. We describe our experience (effectiveness of coagulation, intraoperative handling, and the use as a dissecting tool) with a new type of coagulation forceps, the Calvian endo-pen (Sutter Medizintechnik, Freiburg, Germany) during EETS.

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 Deep-seated high-grade gliomas (HGGs) represent a unique surgical challenge because they reside deep to critical cortical and subcortical structures and infiltrate functional areas of the brain. Therefore, accessing and resecting these tumors can often be challenging and associated with significant morbidity. We describe the use of minimally invasive approaches to access deep-seated HGGs to achieve extensive resections while minimizing surgical morbidity.

Concepts: Medicine, Brain, Brain tumor, Cerebral cortex, Neurology, Minimally invasive, Challenge

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 Synchronous cerebellopontine angle (CPA) tumors are a rare entity. Several publications refer to surgery for such tumors and their classification. Yet, there are no publications on upfront radiosurgery for synchronous CPA tumors.