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Biomedical subjects

A Koerbel

Publications and source records attributed to A Koerbel.

12 recordsLinked to original sources

Endoscope-assisted retrosigmoid intradural suprameatal approach to the middle fossa: anatomical and surgical considerations.

INTRODUCTION: Lesions involving the posterior and middle fossa may be reached by several surgical approaches depending mostly on tumors' location and characteristics. The retrosigmoid intradural suprameatal approach has been used to remove tumors of the posterior fossa extending into Meckel's cave and the middle fossa. With large tumors, this approach may allow exposure of the oculomotor and optic nerves, the supraclinoid internal carotid and communicating posterior arteries. METHODS: Three formaldehyde-fixed specimens have been prepared on both sides using the conventional retrosigmoidal-suprameatal approach. The entire endoscopic preparations have been documented via a digital recording system, using a 5mm endoscope with a 25 degrees perspective. The authors describe the anatomical corridor and technique of the endoscope-assisted retrosigmoid intradural suprameatal approach to lesions that are located predominantly within the posterior fossa and supratentorial extension into Meckel's cave, sellar and parasellar region. CONCLUSIONS: The endoscope-assisted suprameatal approach provides exposure of the antero-medial middle fossa even in cases of skull base lesions that have not caused significant displacement of neurovascular structures.

Cadaver↗

The midline suboccipital subtonsillar approach to the hypoglossal canal: surgical anatomy and clinical application.

Primary lesions of the hypoglossal canal, such as hypoglossal schwannomas, are rare. No consensus exists with regard to the surgical approach of choice for treatment of these lesions. Usually, lateral transcondylar approaches have been used. The authors describe the surgical anatomy of the midline subtonsillar approach to the hypoglossal canal. This approach includes a midline suboccipital craniotomy, dorsal opening of the foramen magnum and elevation of ipsilateral cerebellar tonsil to expose the hypoglossal nerve and its canal. The midline subtonsillar approach permits a straight primary intradural view to the hypoglossal canal. There is no necessity of condylar resections. The surgical anatomy of the subtonsillar approach is described and illustrated by an example of a case.

Brain Neoplasms↗

Atypical teratoid-rhabdoid tumor spreading along the trigeminal nerve.

We here describe the case of a boy with an atypical teratoid-rhabdoid tumor (ATRT) of the 4th ventricle at 1 year of age and a local tumor recurrence at 19 months of age. Due to brainstem infiltration, only incomplete tumor resection was possible each time. High-dose chemotherapy, stem cell transplantation and irradiation resulted in complete tumor remission on a control MRI. At 8 years of age, another tumor appeared extending from the cerebellopontine angle along the right trigeminal nerve through Meckel's cave into the cavernous sinus. The trigeminal tumor was not in continuity with the primary ATRT but was located within the field of prior irradiation, neuroradiologically mimicking a schwannoma or a meningioma. The origin of the trigeminal tumor as a late metastasis of the former ATRT or as a less likely irradiation-induced secondary ATRT and the operative approach are discussed.

Brain Neoplasms↗

Trigeminocardiac reflex during skull base surgery: mechanism and management.

BACKGROUND: We study the occurrence and management of the trigeminocardiac reflex (TCR) during neurosurgical procedures for lesions of the skull base. METHOD: Two hundred patients underwent neurosurgical procedures for various skull base lesions and were evaluated retrospectively for the occurrence of the TCR during surgery. This phenomenon was defined as the onset of bradycardia lower than 60 beats/minute and hypotension with a drop in mean arterial blood pressure of 20% or more due to intra-operative manipulation or traction on the trigeminal nerve. FINDINGS: Sixteen patients (8%) had a TCR intra-operatively (7 vestibular schwannomas, 5 sphenoid wing meningiomas, 3 petroclival meningiomas, 1 intracavernous epidermoid cyst). In all 16 patients with a TCR the postoperative courses presented no complications that could be directly related to this intra-operative phenomenon. CONCLUSIONS: Due to the intracranial course of the trigeminal nerve several surgical procedures at the anterior, middle and posterior skull base may elicit the trigeminocardiac reflex. Continuous monitoring of hemodynamic parameters allows the surgeon to interrupt surgical manoeuvres immediately upon the occurrence of the TCR. This technique is sufficient for the heart rate and the arterial blood pressure to return to normal levels without the necessity of additional anticholinergic medication.

Adult↗

Meningioma of the accessory nerve extending from the jugular foramen into the parapharyngeal space.

A 35-year-old man presented with pain in the right shoulder and neck for 18 months. The neurological examination revealed complete accessory nerve palsy on the right side without further deficits. Magnetic resonance imaging showed a right parapharyngeal tumour expanding into the posterior fossa through the jugular foramen without dural attachment and absence of invasion into the middle ear cavity or internal auditory meatus. Intraoperative inspection disclosed a tumour originating from the accessory nerve. Histological diagnosis revealed a meningothelial meningioma with invasion of the epineural space. To the knowledge of the authors this is the first report of an accessory nerve meningioma in the jugular foramen associated with a posterior fossa component and extension into the parapharyngeal space.

Accessory Nerve Diseases↗

Acute subdural haematoma without subarachnoid haemorrhage caused by rupture of an internal carotid artery bifurcation aneurysm: case report and review of literature.

Spontaneous pure acute subdural haematoma (ASDH) without intraparenchymal or subarachnoid haemorrhage caused by a ruptured cerebral aneurysm is extremely rare. To our knowledge, the present case is the first report of an internal carotid artery bifurcation aneurysm presenting as pure ASDH. Suitable diagnostic investigations and therapeutic strategies are discussed. Arterial origin of bleeding should be considered in all cases of non-traumatic ASDH and a vascular anomaly has to be excluded. The neurological status on admission dictates the appropriate timing and methodology of the neuroradiological investigations.

Aneurysm, Ruptured↗

[Epidural spinal cavernous angioma: case report].

Epidural spinal cavernous angiomas account for approximately 4% of all spinal epidural tumors. More recently the diagnosis has become more frequent due to refinement of imaging modalities. We describe a 50-year-old woman with a spinal epidural cavernous angioma at L1-L2, which was successfully surgical treated. Clinical picture, imaginology and treatment of this entity is reviewed.

Epidural Neoplasms↗

[Internal carotid bilateral occlusion, meningovascular syphilis and AIDS: case report].

We report a case of bilateral occlusion of internal carotid arteries, presenting with right hemiparesis and hypoesthesia, associated to meningovascular syphilis in a patient with AIDS. CT scan showed few small hypodense lesions, with a predominance on the left side, and the angiography showed bilateral occlusion of the carotid arteries. The association between syphilis and AIDS is not unusual, but the paucity of symptoms, probably due to a slow and gradual occlusion is not commonly reported.

Acquired Immunodeficiency Syndrome↗

Rosai-Dorfman disease involving the cranial base, paranasal sinuses and spinal cord.

Rosai-Dorfman disease is a lymphoproliferative disease that rarely involves the central nervous system. A 32-year-old patient with an extensive process involving the petroclival region, cavernous sinuses, suprasellar region, anterior cranial fossa, paranasal sinuses, nasal cavity and spinal cord is reported. Sinus histiocytosis with massive lymphadenopathy lesions may be dural-based and located in the skull base. As these lesions may clinically and radiologically mimic meningiomas as well as other disorders, Rosai-Dorfman disease should be included in the differential diagnosis of extensive lesions involving the intracranial and spinal compartments along with meningiomatosis and inflammatory diseases. The individual management of Rosai-Dorfman disease may be challenging due to diffuse involvement of neurovascular structures at the skull base.

Adult↗