Carlos R. Goulart

Cervical Spondylotic Myelopathy: Pathophysiology, Diagnosis, and Surgical Techniques

Cervical spondylotic myelopathy is a degenerative spinal disease which may lead to significant clinical morbidity. The onset of symptoms is usually insidious, with long periods of fixed disability and episodic worsening events. Regarding the pathophysiology of CSM, the repeated injuries to the spinal cord are caused by both static and dynamic mechanical factors. The combination of these factors affects the spinal cord basically through both direct trauma and ischemia. Regarding the diagnosis, both static and dynamics X-rays, as well as magnetic resonance imaging are important for preoperative evaluation as well as individualizing surgical planning. The choice of the most appropriate technique is affected by patients clinical condition radiologic findings, as well as surgeons experience. In opposition to the old belief that patients presenting mild myelopathy should be treated conservatively, there has progressively been amount of evidence indicating that the clinical course of this disease is progressive deterioration and that early surgical intervention improves long-term functional recovery and neurological prognosis.

Cerebral Melanoma Metastases: A Critical Review on Diagnostic Methods and Therapeutic Options

Malignant melanoma represents the third most common cause for cerebral metastases after breast and lung cancer. Central nervous system (CNS) metastases occur in 10 to 40% of patients with melanoma. Most of the symptoms of CNS melanoma metastases are unspecific and depend on localization of the lesion. All patients with new neurological signs and a previous primary melanoma lesion must be investigated. Although primary diagnosis may rely on computed tomography scan, magnetic resonance images are usually used in order to study more precisely the characteristics of the lesions in and to embase the surgical plan. Other possible complementary exams are: positron emission tomography, iofetamine cintilography, immunohistochemistry of liquor, monoclonal antibody immunocytology, optical coherence tomography, and transcriptase-polymerase chain reaction. Treatment procedures are indicated based on patient clinical status, presence of unique or multiple lesions, and family agreement. Often surgery, radiosurgery, whole brain radiotherapy, and chemotherapy are combined in order to obtain longer remissions and optimal symptom relieve. Corticoids may be also useful in those cases that present with remarkable peritumoral edema and important mass effect. Despite of the advance in therapeutic options, prognosis for patients with melanoma brain metastases remains poor with a median survival time of six months after diagnosis.

Osteoblastomas of the spine: a comprehensive review

Osteoblastomas are primary bone tumors with an affinity for the spine. They typically involve the posterior elements, although extension through the pedicles into the vertebral body is not uncommon. Histologically, they are usually indistinguishable from osteoid osteomas. However, there are different variants of osteoblastomas, with the more aggressive type causing more pronounced bone destruction, soft-tissue infiltration, and epidural extension. A bone scan is the most sensitive radiographic examination used to evaluate osteoblastomas. These osseous neoplasms usually present in the 2nd decade of life with dull aching pain, which is difficult to localize. At times, they can present with a painful scoliosis, which usually resolves if the osteoblastoma is resected in a timely fashion. Neurological manifestations such as radiculopathy or myelopathy do occur as well, most commonly when there is mass effect on nerve roots or the spinal cord itself. The mainstay of treatment involves surgical intervention. Curettage has been a surgical option, although marginal excision or wide en bloc resection are preferred options. Adjuvant radiotherapy and chemotherapy are generally not undertaken, although some have advocated their use after less aggressive surgical maneuvers or with residual tumor. In this manuscript, the authors have aimed to systematically review the literature and to put forth an extensive, comprehensive overview of this rare osseous tumor.

Retropharyngeal abscess with secondary osteomyelitis and epidural abscess: proposed pathophysiological mechanism of an underrecognized complication of unstable craniocervical injuries: case report.

Because of the proximity of the oropharynx (a naturally contaminated region) to the spinal structures of the craniocervical junction, it is possible that small mucosal lacerations in the oropharynx caused by unstable traumatic craniocervical injuries may become contaminated and lead to secondary infection and osteomyelitis. In this report, the authors describe the case of a previously healthy and immunocompetent patient who developed a large retropharyngeal abscess with spinal osteomyelitis after a high-energy craniocervical injury. This unusual report of osteomyelitis with a delayed presentation after a high-energy traumatic injury of the craniocervical junction highlights the possibility of direct injury to a specific area in the oropharyngeal mucosa adjacent to the osteoligamentous structures of the craniocervical junction, an overall underrecognized complication of unstable craniocervical injuries.

Anatomical nuances of the internal carotid artery in relation to the quadrangular space

OBJECTIVE The aim of this study was to evaluate the anatomical variations of the internal carotid artery (ICA) in relation to the quadrangular space (QS) and to propose a classification system based on the results. METHODS A total of 44 human cadaveric specimens were dissected endonasally under direct endoscopic visualization. During the dissection, the anatomical variations of the ICA and their relationship with the QS were noted. RESULTS The space between the paraclival ICAs (i.e., intercarotid space) can be classified as 1 of 3 different shapes (i.e., trapezoid, square, or hourglass) based on the trajectory of the ICAs. The ICA trajectories also directly influence the volumetric area of the QS. Based on its geometry, the QS was classified as one of the following: 1) Type A has the smallest QS area and is associated with a trapezoid intercarotid space, 2) Type B corresponds to the expected QS area (not minimized or enlarged) and is associated with a square intercarotid space, and 3) Type C has the largest QS area and is associated with an hourglass intercarotid space. CONCLUSIONS The different trajectories of the ICAs can modify the area of the QS and may be an essential parameter to consider for preoperative planning and defining the most appropriate corridor to reach Meckels cave. In addition, ICA trajectories should be considered prior to surgery to avoid injuring the vessels.

The clinical importance of basioccipital developmental defects

Dear Editor: We read with great interest the article by Tubbs et al. entitled “The human calvaria: a review of embryology, anatomy, pathology, and molecular development,” published in Child’s Nervous System (2012;28(1):23–31). In their paper, the authors provide an extensive review about the development, pathology, and molecular formation of the human calvaria. Although in their approach to the neurocranium the authors focus their attention on the human calvaria (also known as membranous cranium), this article also provides interesting information about the development of the cranial base (or chondrocranium). As highlighted by the authors, the embryological processes responsible for the formation of the final architecture of the skull starts with the chondrification of the mesenchyme of the spheno-occipital region during the seventh fetal week, further extending to the facial bones and lately spreading and expanding the neurocranial cavity to accommodate the enlarging forebrain. Although the presented knowledge about the embryological development of the calvaria seems to have clear clinical applications due to the importance of the several types of craniosynostosis in the neurosurgical pediatric practice, it is important to emphasize that the knowledge about the development of the skull base should not be regarded as secondary. In fact, although most of the skull base developmental defects usually represent incidental findings on imaging exams, they may constitute an unrecognized cause of recurrent meningitis, especially after paranasal sinus infections. With special clinical importance is the so-called “Canalis Basilaris Medianus” (CBM), a special type of basiocipital developmental defect. Although the reported incidence of such anomaly in old CT scans series was around 3.8% [3], a most recent report found a much higher incidence (around 20%) [6]. In early embryological development, the four sclerotomes of the first four somites (called hypoglossal somites) are incorporated into the skull base. At this location, these elements fuse and establish the basioccipital plate, which surrounds the notochord. The spinal and the pre-chordal part are responsible for the formation of the chondrocranium, also called the primordial cranium. The embryology and development of the sphenoid bone are complex and involve up to 15 separate enchondral and intramembranous ossification centers [5]. According to this mosaic-like formation, several interosseous sutures are established and may, in some cases, persist towards adulthood [11]. In fact, the absence of complete fusion of these embryological ossification centers may lead to the persistence of seven other types of anterior skull base foramina or pseudoforamina besides the “Canalis Basilaris Medianus’ [6]. Two theories have been proposed in the literature to explain the development of the CBM. The most accepted one suggests that the defect would be an osseous remnant of a basivertebral vein present only in the embryological phase of development [4, 8]. Another theory relates the origin of CBMs to notochordal development [2]. It is known that around the fifth week, the notochord becomes enclosed by the bodies of the upper cervical vertebrae. During regular embryological development T. A. Mattei (*) Neurosurgery Department, University of Illinois at Peoria, 828 NE Glen Oak Avenue, Apt. 302, Peoria, IL 61603-3285, USA e-mail: tobiasmattei@yahoo.com

Seizure-like activity during etomidate-modified Wada test interfere with the evaluation of cognitive functions?

1. Komninos J, Vlassopoulou V, Protopapa D, et al. Tumors metastatic to the pituitary gland: case report and literature review. J Clin Endocrinol Metab 2004;89:574-580.2. Fassett DR, Couldwell WT. Metastases to the pituitary gland. Neurosurg Focus 2004;16:E8.3. Hoellig A, Niehusmann P, Flacke S, Kristof RA. Metastasis to pituitary ade-noma: case report and review of the literature. Cen Eur Neurosurg 2009; 70:149-153.4. Bhatoe HS, Badwal S, Dutta V, Kannan N. Pituitary metastasis from med-ullary carcinoma of thyroid: case report and review of literature. J Neu-rooncol 2008;89:63-67. 5. Morita A, Meyer FB, Laws ER Jr. Symptomatic pituitary metastases. J Neu-rosurg 1998;89:69-73.

Successful outcome after endovascular thrombolysis for acute ischemic stroke with basis on perfusion-diffusion mismatch after 24 h of symptoms onset

Background: Although intravenous thrombolysis is the Food and Drug Administration-approved treatment for acute ischemic stroke (AIS) within 3 h, combined intravenous and intra-arterial thrombolysis with endovascular techniques may be able to extend this traditional time window. Case Description: We present the clinical evolution of a 45-year-old male presenting with acute left hemiparesis. Magnetic resonance imaging revealed a small diffusion restriction at the right basal ganglia with perfusion compromise in the entire right middle cerebral artery (MCA) territory. Angiography revealed a complete occlusion of MCA at its M1 segment. The patient underwent endovascular mechanical thrombectomy with additional intra-arterial thrombolysis more than 24 hours after the onset of the initial symptoms and experienced complete vessel recanalization. At 1 year, the patient had global independence with minor residual motor impairment in the left arm. Conclusions: We report the case of a successful thrombolytic therapy following AIS performed more than 24 h after the initial symptoms based on the presence of a perfusion-diffusion mismatch. This report is expected to stimulate the development of future prospective studies with special focus on the role of perfusion-diffusion mismatch in patient selection for treatment of AIS, especially in those presenting outside the traditional time window.