Anatomical and morphometrical evaluation of the jugular tubercle

BACKGROUND

The jugular tubercle (JT) is an important part of the craniovertebral junction. The removal of the JT in the far-lateral approach provides a significant increase in the operative space. The purpose of this morphometrical study was to define the anatomical variations of the JT.

METHODS

Thirty-eight dry skulls were included in this study. Seven anatomical parameters were defined and analyzed. The JT, hypoglossal canal (HC), jugular bulb, condylar fossa, occipital condyle (OC), internal jugular foramen, and condylar canal were selected as landmarks. The measurements were made separately for the right and the left sides.

RESULTS

Significant morphological variations in the JT were noted. A protuberance was apparent on the JT and classified according to its shape, size, and number. Morphological differences of protuberance of JT were described and classified into seven different types as follows: flat (Type I), sharp (Type II), circular (Type III), pin-point (Type IV), large (Type V), double (Type VI), and unclassified (Type VII). The HC was observed in all specimens. To define the relationship between the JT and the intracranial orifice of the HC, four localizations were identified. To define the relationship between the JT and the intracranial orifice of the HC.

CONCLUSIONS

Variations of the JT and the relationship of the JT to the neighboring bone and neural structures are important for modifications of the far-lateral approach. This study presents a detailed anatomical analysis of the shape, size, and orientation of the JT with a new description of protuberance of JT classified into seven types.

Cerebral tuberculoma mimicking high grade glial tumor

Tuberculosis has been an important public health problem in both developing and develop nations. Tuberculosis of the central nervous system is rare. Tuberculosis meningitis and tuberculoma are the two most important manifestations of tuberculosis of the CNS. Intracranial tuberculomas may be solitary or multiple. Solitary tuberculomas may be indistinguishable from cranial abscess or primary brain tumor. It is necessary to rule out tuberculoma in patients with intracranial mass lesions. We present a case of tuberculoma mimicking a high grade glial tumor on magnetic resonance imaging and clinical presentation. A 30-year-old woman presented with one-month history of epilepsy. Cranial magnetic resonance imaging showed a left occipital peripheral ring-enhanced lesion with central necrosis. There was a strong suspicion of glial tumor. The lesion was totally excised with left occipital craniotomy. Histological examination of mass revealed a tuberculoma. The patient was treated with antituberculous chemotherapy.

Primary brain tumors associated with cerebral aneurysm: report of three cases

The primary brain tumors associated with cerebral aneurysms are rare in neurosurgical practice. The present article constitutes an evaluation of the management of coexistent primary brain tumor and cerebral aneurysm. A retrospective study of three cases of primary brain tumor with cerebral aneurysm was performed. We evaluated the complications and clinic outcomes by assessing the clinical and imaging findings. Case 1 presented with a subarachnoid hemorrhage from an aneurysm of the anterior communicating artery, with an incidental left frontal oligodendroglioma. Case 2 presented with chronic headache due to left frontal convexity meningioma, with proximal internal carotid artery aneurysm which was found incidentally during preoperative magnetic resonance angiography. Case 3 was admitted to our hospital complaining of headache, memory disturbance, and weakness in her left lower extremity. Magnetic resonance imaging revealed right frontal lymphoma and an unruptured aneurysm at the left middle cerebral artery. Preoperative magnetic resonance imaging revealed right frontal lymphoma and unruptured left middle cerebral artery. The frequency of primary brain tumor and cerebral aneurysm coexistence is increasing due to improvements in high-resolution imaging. In these complicated cases, the management will differ according to each pathology present, and this is an important problem for a neurosurgeon.

Primary cerebellopontine angle craniopharyngioma in a patient with Gardner syndrome

Craniopharyngiomas usually involve the sella and suprasellar space. Ectopic craniopharyngiomas have rarely been reported at the cerebellopontine angle (CPA). We report a rare primary craniopharyngioma of the CPA without extension into the sellar region. The lesion was initially detected by MRI during investigation of multiple scalp fibromas. Multiple osteomas of the skull and face were detected 2years later, and colonic adenomatous polyposis was detected 4years later; typical features of Gardner syndrome. This is the third report of a primary CPA craniopharyngioma in a patient with Gardner syndrome.

Surface anatomy of the transverse sinus for the midline infratentorial supracerebellar approach

AIM

Knowing the location of the transverse sinus in the midline supracerebellar infratentorial approach is important to prevent its inadvertent injury. The external landmarks of the occipital bone have been studied in this anatomic study in order to reveal their relationship with the transverse sinus.

MATERIAL AND METHODS

Fifty-two dried skulls were used to study the relationship of the transverse sinus with various surface bone structures. The key bone surface structures identified in each specimen were the superior nuchal line, the inferior nuchal line, the inion, internal occipital protuberance, and the transverse sulcus.

RESULTS

The distance from the inion to the inferior nuchal line in specimens ranged from 12.7 mm to 37.7 mm. The distance from the inferior nuchal line to the midline foramen magnum in the specimens ranged from 19 mm to 34.75 mm. The width of the proximal transverse sulcus ranged from 2.6 mm to 10.16 mm with an average of 6.43 mm on the right side and 3.4 mm to 10.6 mm with an average of 6.15 mm on the left.

CONCLUSION

The first and most superior burr hole for midline supracerebellar infratentorial approach can be safely placed approximately 1 cm below the inferior nuchal line. A burr hole in this localization will avoid the transverse sinus.

Hydatid cyst of the craniocervical junction: case report

OBJECTIVE AND IMPORTANCE

Although rare in developed countries, hydatid disease is a serious parasitic infection in endemic areas. Spinal disease most commonly involves the thoracic region, and involvement of the upper cervical spine is extremely rare. In this report, a case of hydatid disease involving the craniocervical junction is presented, along with a review of the literature.

CLINICAL PRESENTATION

A 44-year-old man presented with the complaint of neck pain. The results of his physical and neurological examinations were within normal ranges, except for pain exacerbated by neck motion and spasm of the cervical musculature. Magnetic resonance imaging demonstrated a cystic lesion involving the odontoid process and body of C1 and C2, with thin and regular cyst walls and cyst contents similar in intensity to that of cerebrospinal fluid. The results of serological tests performed with the suspected diagnosis of hydatid disease were positive.

INTERVENTION

The patient initially underwent surgery to provide stabilization of the craniocervical junction, using autogenous bone graft and sublaminar wiring from the occiput to C3 via a posterior approach. The cyst was approached via a transoral route, using a U-shaped pharyngeal incision. There were no neurological deficits after surgery. Postoperative magnetic resonance imaging scans confirmed complete excision of the cyst, and the patient was discharged on the 12th postoperative day. He received six cycles of albendazole treatment, each consisting of 28 days with an intervening drug-free period of 2 weeks. Magnetic resonance imaging scans performed 1 year after surgery revealed the patient was still disease-free.

CONCLUSION

Hydatid disease should be considered in the differential diagnosis of spinal cord compression, especially in endemic areas. Although the chance of obtaining a cure is unlikely, radical surgery coupled with antihelminthic therapy seems to provide long-lasting relief.

A case of McCune-Albright syndrome associated with Gs alpha mutation in the bone tissue

The syndrome of McCune-Albright syndrome (MAS) is clasically defined as a triad presentation with the findings of polyostotic fibrous dysplasia, café-au-lait spots, and sexual precocity. However, not all patients present with complete symptoms. A 52-year-old man was diagnosed as having a variant of McCune-Albright syndrome with the following findings: polyostotic fibrous dysplasia, acromegaly due to pituitary tumor and subclinical hyperthyroidism due to toxic multinodular goiter. Sexual precocity and café-au-lait spots were not noted. Acromegaly was confirmed by laboratory examination (IGF-1, glucose suppression test and TRH stimulation test). Long acting somatostatin analogue was used as treatment. Although the pituitary tumor could not be removed due to technical problems, mass lesions on the cranium were removed subtotally. Histopathological evaluation demonstrated that the lesion complied with fibrous dysplasia. Genomic DNAs were isolated from the craniofacial bones and peripheral leucocytes of the patient. After amplifying the related regions, Gs alpha (Gs alpha) gene was analysed by automatic DNA sequence analysis. An activating mutation of the Gs alpha gene (Arg 201 Cys) was found in the genomic DNA isolated from the bone tissue of the patient, but not in the genomic DNA isolated from the blood. We described a case of MAS associated with Gs alpha mutation in the bone tissue, presenting with polyostotic fibrous dysplasia, subclinical hyperthyroidism and acromegaly.

Evaluation of mild head injury in a pediatric population

Approximately 5 million children present to emergency departments, seeking care for head injuries, each year, and 80% of these children are classified as cases of mild head injury. Due to the huge number of patients and low frequency of intracranial lesions in this group, obtaining a computed tomography scan for each and every patient is a significant economic problem. This study was conducted to identify the clinical parameters and the radiographic findings that may be associated with intracranial lesions in children with mild head injury. 421 patients, with a Glasgow Coma Scale score of 15 and without any focal neurological deficit, were studied. Intracranial lesion was noted in 37 cases (8.8%). Sensitivity of a plain radiogram was 43.2%, and specificity was 93%. An intracranial pathology was demonstrated in 28.9% of the patients with a linear skull fracture. The only clinical parameters associated with an increase in the frequency of detection of intracranial lesions were posttraumatic seizures and loss of consciousness. Age, sex, headache, vomiting and scalp lacerations were not associated with a higher frequency. Even when patients with a history of loss of consciousness or posttraumatic seizure were subtracted from the study group, intracranial lesions were noted in 4.1% of the cases, and in 1.8% neurosurgical intervention was required. Computed tomography is the gold standard in the evaluation of pediatric patients with mild head trauma, and every child who has experienced a head injury should undergo a cranial computed tomography evaluation, even if he or she appears in perfect health.

Surface anatomy of the posterolateral cranium regarding the localization of the initial burr–hole for a retrosigmoid approach

Knowing the location of the venous sinuses is essential for the localization of the initial burr-hole for a retrosigmoid approach, in order to avoid inadvertent entry into the venous sinuses and limitation of the size of the bony opening. In this anatomic study, external landmarks of the posterolateral cranium have been studied, in order to reveal the relationship with the venous sinuses. Eighty-four dried adult human skulls were studied and study of both sides yielded 168 sides. Morphometric measurements of the posterolateral cranium have been performed and relations of the external landmarks with the venous sinuses have been studied. The anatomic position of the asterion was variable. The superior nuchal line was roughly parallel and below the lower margin of the sulcus of transverse sinus in all specimens. The sigmoid sinus, between the superior and inferior bends, seemed to descend along an axis defined by the junction of the squamosal-parietomastoid suture and the mastoid tip, in a slightly oblique fashion. In conclusion, a burr-hole placed just below the superior nuchal line and posterior to the axis defined by the mastoid tip and the squamosal-parietomastoid suture junction is appropriate for both avoiding inadvertent entry into the sinus and limiting the size of the craniotomy.

Morphometric evaluation of subaxial cervical vertebrae for surgical application of transpedicular screw fixation

STUDY DESIGN

A morphometric evaluation of pedicle projections in 29 cervical spinal columns (C3-C7) for three-dimensional surgical anatomy for safe surgery was proposed.

OBJECTIVE

In this study, pedicles and intimate structures of the subaxial vertebrae from C3 to C7 were evaluated to provide some morphometric data for cervical transpedicular screw fixation.

SUMMARY OF BACKGROUND DATA

Detailed knowledge of surgical anatomy and variation of the subaxial vertebrae is a must for safe and effective surgery of the region. Although there are several clinical studies of transpedicular fixation, few studies have been performed on cervical pedicle measurements and their projection.

METHODS

In 29 dried bone cervical spinal columns (C3-C7), pedicle dimensions (pedicle height, width, length), measurements of lateral mass and pedicle length distance and pedicle axis length, investigation of distances of superior facet-midpedicle axis and inferior facet-midpedicle axis, and transverse and sagittal angles of the pedicles were performed in linear and angular measurements.

RESULTS

The obtained data from the series revealed that the mean values were approximately ranging from 6.7 to 7.2 mm for pedicle height, 4.4 to 4.9 mm for pedicle width, 5.3 to 6.2 mm for pedicle length, 15.3 to 16.0 mm for lateral mass and pedicle length, 22.2 to 27.7 mm for pedicle axis length, 3.8 to 5.3 mm for superior facet-midpedicle axis distance, 9.9 to 12.0 mm for inferior facet-midpedicle axis distance, 42.3 degrees to 51.5 degrees for transverse angle, and 5.2 degrees to 14.1 degrees for sagittal angle.

CONCLUSIONS

Linear measurements of pedicle dimensions and also axial angles from horizontal and vertical planes may provide some anatomic limitations for subaxial cervical transpedicular screw fixation, and also contribute to the safety of the surgical procedure. One should also rely on tomographic data and computer-assisted guidance systems.

[Self migrating intracranial bullets]

We report herein two patients in whom bullets migrated into adjacent lateral ventricles in the brain and moved freely as a consequence of gravity. A rewiew ofthe literature suggests that spontaneous migration ofintracerebral bullets is being eased by cerebral softness, specific gravity of the bullet compared with brain tissue. ln patients undergoing the surgical removal of intracerebral or intraventricular bullets, an x-ray is recommended after final positioning.