Primary Sonic Hedgehog-activated dorsal brainstem medulloblastoma and ipsilateral cerebellar atrophy in an adult.

Medulloblastoma (MB) that arises outside the cerebellum from cells of the dorsal brainstem is rare. The most common subtype of MB in the dorsal brainstem is the Wingless (WNT) subtype that contains activating mutations in the WNT pathway effector CTNNB1. Ipsilateral cerebellar hemi-atrophy with a brainstem tumour is a finding that is usually documented with brainstem gangliogliomas as a possible specific imaging sign. We present a case of a 23-year-old female with progressive headache, imbalance on walking, double vision and difficulty in swallowing for a year. Magnetic resonance imaging demonstrated a mass with prominent restricted diffusion on the dorsal surface of the lower brainstem with ipsilateral cerebellar atrophy. The final histopathological diagnosis was a Sonic Hedgehog (SHH)-activated and TP53 wild-type primary lower dorsal brainstem MB. Primary SHH-activated TP53 wild-type dorsal brainstem MB is extremely rare, and as far as we know, the association of the tumour with ipsilateral cerebellar hemi-atrophy in an adult has never been reported. MB should be included in the differential diagnosis of focal dorsal brainstem tumours, even in the presence of ipsilateral cerebellar hemi-atrophy.

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.

The relation between surgical cleavage and preoperative neuroradiological findings in intracranial meningiomas.

BACKGROUND: Meningiomas are generally benign masses, and in many cases they do not invade the brain. Therefore their potential to provide cures is high. The most important cause of the development of recurrence in the post-operative period is subtotal resection. Any information that will allow us to perform total mass resection will be beneficial in terms of long-term good clinical procedure. Our aim in this study is to obtain the radiological data from which we can obtain accurate information in terms of the surgical cleavage between the tumor and parenchyma during the surgical planning of the meningiomas. METHODS: We evaluated 85 cases with intracranial meningioma that were treated by the same microsurgical technique. All posterior fossa and skull base meningiomas were not included in the study. RESULTS: Tumor size was smaller than 3 cm in 19 cases, between 3 and 6 cm in 46 cases, and bigger than 6 cm in 20 cases. The cleavage line between the tumor capsule and the cortex underneath was extrapial in 32 cases, subpial in 29 cases, and mixed in 24 cases. Dominant arterial supply was dural in 46 cases. Thirty-three cases were predominantly mixed and 6 cases were predominantly corticopial. At magnetic resonance images, 16 of 28 cases which showed clear tumor-cortex interface, had an extrapial cleavage line. CONCLUSIONS: When surgical treatment of intracranial meningiomas are considered, it is necessary to examine if there is a surgically safe border between the cortex underneath in the preoperative images. It can be concluded that it is appropriate to operate small meningiomas which are on the sensitive regions of the brain when they are in their earlier stages and still have an extrapial cleavage.

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.

Bilateral Lhermitte-Duclos disease.

Lhermitte-Duclos disease (LDD) is a pathologic entity with progrediating, diffuse hypertrophy chiefly of the stratum granulosum of the cerebellum. Typically LDD is a unilateral lesion of the cerebellum or in vermis. Here we report a case of LDD with bilateral lesions of cerebellar hemispheres managed surgically. A 28-year-old woman presented with one-year history of progressive headache, nausea, vomiting, and blurred vision. Neurologic examination revealed a bilateral mild papilledema, mild dysmetria, and dysdiadochokinesia. The cerebellar lesions caused moderate mass effect in posterior fossa with hydrocephalus, and Chiari type I malformation. We performed the suboccipital-retrosigmoid approach, and removed completely the left intracerebellar mass. Symptoms related to elevated intracranial pressure disappeared in a short period postoperatively.

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.

Evaluation of the bony landmarks in transcondylar approach.

BACKGROUND: The aim of this study is to define the anatomic landmarks which are necessary for transcondylar approach and to determine the importance of these structures during surgical resection. METHODS: 56 dry skulls were included in this study. Landmarks were detected. Some distances and angles, which were determined before, were measured and the anatomical structures were observed. 21 parameters were examined and analysed in totally 56 dry skulls using 56 foramen magnum, 112 hypoglossal canal and 112 occipital condyles. The landmarks which were used were the anterior and posterior borders of the occipital condyle, the medial and lateral margin of the occipital condyle, basion, opisthion, hypoglossal canal and posterior condylar canal. The measurements were made separately for the right and left sides. RESULTS: The mean length of the occipital condyle was found as 23.1 mm. The distance between the intracranial edge of the hypoglossal canal and anterior margin of the occipital condyle was measured as 11.2 mm in both sides. The distance between the intracranial edge of the hypoglossal canal and posterior margin of the occipital condyle was measured as 12.5 mm at the right side and 12.6 mm at the left one. The mean length of the hypoglossal canal was measured as 10.5 mm at the right side and 10.6 mm at the left one. 14 hypoglossal canals were divided into two compartments by a septum. CONCLUSIONS: In transcondylar approach, the anatomical landmarks should be well known in order to make a safe occipital condyle resection. The distance between the intracranial edge of the hypoglossal canal and posterior margin of the occipital condyle is important for a safe occipital condyle resection, and it was found to be 12.55 +/-0.05 mm in our study. Approximately 12 mm occipital condyle resection can be made without giving damage to the neural tissue. This value is appropriate to the (1/2) of the occipital condyle.

Aneurysmal bone cyst of the sphenoid bone extending into the ethmoid sinus, nasal cavity and orbita in a child.

An aneurysmal bone cyst (ABC) typically involves the long bones of the extremities, thorax, pelvis, or vertebrae. Skull base involvement is rare. We describe the case of a 9-year-old girl with ABC of the skull base. The patient had presented with nasal obstruction and headache over a period of approximately 8 months. The patient had no history of trauma or surgery. Physical and neurological examination findings normal. Magnetic resonance imaging (MRI) showed a multicystic lesion arising from the sphenoid sinus and extending into ethmoid sinus, superior nasal cavity and medial walls of the orbit. The lesion contained thin internal septations that revealed high signal characteristics on all sequences. The lesion was resected via an extended frontal approach without any complications. Histological evaluation confirmed that the lesion was an ABC. The patient did not receive postoperative radiotherapy. No recurrence was observed after 22 months. ABC should be considered in the differential diagnosis of bone neoplasms in this region.

Primary spinal hydatid disease.

Primary spinal hydatid disease is rare. Spinal hydatid disease should be considered in the differential diagnosis of spinal cord compression syndrome in endemic countries and evaluated with imaging and serology. Our case was a 34- year-old man. The patient presented with progressive back pain for 8 months and lower extremity weakness for 3 months. Neurological examination was suggestive of upper motor neuron type of paraperesis. Magnetic resonance images of the thoracal region showed an intradural multicystic lesion. The mass was explored with T 10-11 laminectomy. It had displaced the cord to the right side. The fluid was clear and did not contain pus. The lesion was easily dissected from the cord and was resected totally. The pathological diagnosis was hydatid disease.

Frontal bone and epidural tuberculosis.

Cranial bone and epidural tuberculosis is rare manifestation extrapulmonary tuberculosis. The incidence of tuberculosis of calvaria is on the rise in developing countries because of malnutrition, poor socioeconomic conditions, and immunodeficiency. We present the clinical features, radiology, histopathology, and surgical findings of a case of tuberculosis of the frontal bone with epidural extension. A 46 year-old female had presented with a history of painless right frontal swelling for the previous 4 months. The patient was operated on at a peripheral center for swelling in the right frontal region. In postoperative period, a leak that did not reply to nonspecific antibiotic therapy developed on the lesion. Right frontal epidural effusion was found in the patient who presented our clinic. Histopathological and microbiological examination suggested a diagnosis of tuberculosis.

Removal of clival chordoma in an adolescent thorough combned pterional transsylvian and anterior temporal approach.

Extensive and aggressive surgical removal is treatment of choice for patients who have chordomas of the cranial base. Well-developed microsurgical techniques, as well as good surgical judgment learned from experience are essential to avoid major morbidity. A 14-year-old female presented with progressive headaches and diplopia for three months. Cranial magnetic resonance imaging demonstrated a well-circumscribed mass in the clival region. The mass was totally excised via right combined pterional transsylvian and anterior temporal approach (+ orbitozygomatic osteotomy). The tumor was located extradurally. The resected tumor had the typical histological and immunohistochemical characteristics of chordoma. No radiation therapy or chemotherapy was administered.

Cystic schwannoma of the falx cerebri.

Intracranial parenchymal schwannomas unrelated to a major cranial nerve are uncommon and dural schwannomas are rare. We report a 23-year-old woman without neurofibromatosis admitted with a 3-month history of seizures and left hemiparesis. Radiological investigation revealed a huge cystic tumour in the right cerebral hemisphere, attached to the falx cerebri. The solid part of the tumour showed contrast enhancement. The patient underwent excision of the tumour via a right-sided parietal craniotomy. The histological diagnosis was schwannoma. Recognition of these potentially curable tumours is important and they should be excised if possible.

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.

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.

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.