Sebahattin Cobanoglu

Nocardial brain abscess: Review of clinical management

Nocardiosis has become a significant opportunistic infection over the last two decades as the number of immunocompromised individuals has grown worldwide. We present two patients with nocardial brain abscess. The first patient was a 39-year-old woman with systemic lupus erythematosus. A left temporoparietal abscess was detected and aspirated through a burr-hole. Nocardia farcinica infection was diagnosed. The patient had an accompanying pulmonary infection and was thus treated with imipenem and amikacine for 3 weeks. She received oral minocycline for 1 year. The second patient was a 43-year-old man who was being treated with corticosteroids for glomerulonephritis. He was diagnosed with a ring-enhancing multiloculated abscess in the left cerebellar hemisphere, with an additional two small supratentorial lesions and triventricular hydrocephalus. Gross total excision of the cerebellar abscess was performed via a left suboccipital craniectomy. Culture revealed Nocardia asteroides, and the patient was successfully treated with intravenous ceftriaxone, then oral trimethoprime-sulfamethoxazole for 1 year. The clinical course, radiological findings, and management of nocardial brain abscess are discussed in light of the relevant literature, and current clinical management is reviewed through examination of the cases presented here.

Contralateral subdural effusion after aneurysm surgery and decompressive craniectomy: case report and review of the literature.

We report a complication of decompressive craniectomy in the treatment of aneurismal subarachnoid hemorrhage (SAH) and accompanying middle cerebral artery (MCA) infarction. A 56-year-old man presented with subarachnoid hemorrhage and right sylvian hematoma. He was diagnosed with high-grade SAH and medical therapy was employed. He showed rapid clinical deterioration on day 9 of his admission. Computed tomographic scans showed right MCA infarction and prominent midline shift. Because of the patients rapidly worsening condition, further evaluation to find origin of SAH could not be obtained, and decompressive right hemicraniectomy was performed. During sylvian dissection, right middle cerebral and posterior communicant artery aneurysms were detected and clipped. One week after operation, a contralateral frontoparietal subdural effusion and left to right midline shift was detected and drained through a burr-hole. Through successive percutaneous aspirations, effusion recurred and complete resolution was achieved after cranioplasty and subduroperitoneal shunt procedures. Decompressive craniectomy is generally accepted as a technically simple operation with a low incidence of complications. In the light of this current case, we hypothesize that a large craniectomy may facilitate the accumulation of recurrent effusion on contralateral side creating a resistance gradient between two hemispheres. This point may be especially true for subarachnoid hemorrhage cases requiring aneurysm surgery. We conclusively suggest that subdural effusions may be resistant to simple drainage techniques if a large contralateral craniectomy does exist, and early cranioplasty may be required for treatment in addition to drainage procedures.

Reversible postictal MRI change mimicking structural lesion

A reversible change on magnetic resonance imaging (MRI) following generalised seizure mimicking a tumour-like structural lesion is reported in a 15-year-old patient. MRI revealed a left fronto-parietal cortico-subcortical lesion on T2 weighted images. The control MRI after 5 weeks from the onset revealed no pathological finding. The reversible MRI changes may be the result of a local brain swelling, and a defect of cerebral autoregulation during seizure at the site of activity. The transient nature of such neuroradiological findings have to be taken into consideration in the differential diagnosis because of their similar appearance on imaging to intrinsic brain tumours.

A laboratory training model for interhemispheric-transcallosal approach to the lateral ventricle.

Laboratory training models are essential for developing and refining surgical skills before clinical application of microneurosurgery. Our aim is to train residents of neurosurgery to be familiar with a basic microneurosurgical technique in access to the lateral ventricle via a transcallosal approach. The training material consists of a 2-year-old fresh cadaveric cow cranium. A four-step approach was designed to simulate microneurosurgical dissection along the falx to visualize cingulated gyri, callosomarginal and pericallosal arteries in order to perform callosotomy and access to the lateral ventricle, and finally to the foramen of Monroe. We conclude that the model perfectly simulates standard microneurosurgical steps in interhemispheric-transcallosal approach to the lateral ventricle and to the area of the foramen of Monroe.

Large intradiploic growing skull fracture of the posterior fossa

Growing skull fractures (GSFs) are rare complications of head injury and mostly occur in infancy and early childhood. Location in the posterior fossa and intradiploic development of a GSF is very uncommon. We report a 7-year-old boy with a large, 9×7×4-cm, occipital intradiploic GSF. The lesion developed progressively over a period of 5 years following a documented occipital linear fracture. This case of a GSF developing from a known occipital linear fracture demonstrates that a GSF may reach a considerable size and, although uncommon, intradiploic development and occipital localization of a GSF is possible.

Paraplegia due to spinal subdural hematoma as a complication of posterior fossa surgery: Case report and review of the literature

Although blood contamination of cerebrospinal fluid (CSF) after an intracranial operation is possible, development of a symptomatic spinal hematoma after a posterior fossa surgery has never been reported. A 43-year-old woman underwent a posterior fossa tumor removal in the prone position with no intraoperative difficulty. On the second postoperative day, she complained of severe epigastric pain and developed a rapid onset of paraplegia with anesthesia below the thoracic 5 spinal level. The emergency cranial and spinal MRIs revealed a spinal extramedullary hemorrhage spreading to the whole spinal regions, just sparing the cauda equina area. There was a prominent localized hematoma formation surrounding and compressing the spinal cord at the upper thoracic levels, which was evacuated via an urgent laminectomy. The patient showed partial neurological recovery after the decompression. Development of the spinal hematoma was explained by the movement of blood from the tumor bed into the spinal canal under the effect of gravity, during or after the operation. A 30 degrees head elevation might facilitate the accumulation of blood. Localization of the hematoma formation may be caused by the fact that the upper thoracic levels constitute the apex of the kyphosis. We conclusively suggest that a spinal hematoma should be taken into consideration as a rare but potentially severe complication of a posterior fossa surgery. Meticulous hemostasis and isolation of the surgical area from the spinal spaces are essential. Overdrainage of CSF should be abandoned. Postoperatively, patients should be monitored for spinal findings as well as cranial signs.

Giant cervicothoracic extradural arachnoid cyst: case report

The pathogenesis, etiology, and treatment of the spinal arachnoid cyst have not been well established because of its rarity. A 57-year-old male was presented with spastic quadriparesis predominantly on the left side. His radiological examination showed widening of the cervical spinal canal and left neural foramina due to a cerebrospinal fluid - filled extradural cyst that extended from C2 to T2 level. The cyst was located left anterolaterally, compressing the spinal cord. Through a C4–T2 laminotomy, the cyst was excised totally and the dural defect was repaired. Several features of the reported case, such as cyst size, location, and clinical features make it extremely unusual. The case is discussed in light of the relevant literature.

A laboratory training model in fresh cadaveric sheep brain for microneurosurgical dissection of cranial nerves in posterior fossa.

A neurosurgical laboratory training model is designed for residents of neurosurgery to handle surgical microscopes and microneurosurgical instruments. The material consists of a one-year-old fresh cadaveric sheep cranium. A four-step approach was designed to simulate microneurosurgical dissection along the posterior fossa cisterns, and to dissect cranial nerves emerging from the brain stem. We conclude that this laboratory training model is useful to allow trainees to gain experience with the general use of an operating microscope, and familiarity with handling cranial nerves.

Two patients with tremor caused by cortical lesions.

Myoclonic tremor due to cortical lesions is a rare condition and must be distinguished from other causes of tremor. This is because the treatment strategies of tremor may differ due to the various etiologies. We present here two cases with myoclonic tremor caused by parietal cortical lesions showing tremulous finger movement provoked by action and posture. Clinical and electrophysiological features of the patients were reported and compared with the features of the patients with cortical tremor in association with cortical reflex myoclonus. Both of our patients responded well to anticonvulsants such as valproate and clonazepam. In patients with acute postural tremor, cortical lesions such as mass occupying lesions, ischemic lesions and arteriovenous malformations should be taken into consideration.

Microsurgical training model for residents to approach to the orbit and the optic nerve in fresh cadaveric sheep cranium

Background: Neurosurgery and ophthalmology residents need many years to improve microsurgical skills. Laboratory training models are very important for developing surgical skills before clinical application of microsurgery. A simple simulation model is needed for residents to learn how to handle microsurgical instruments and to perform safe dissection of intracranial or intraorbital nerves, vessels, and other structures. Materials and Methods: The simulation material consists of a one-year-old fresh cadaveric sheep cranium. Two parts (Part 1 and Part 2) were designed to approach structures of the orbit. Part 1 consisted of a 2-step approach to dissect intraorbital structures, and Part 2 consisted of a 3-step approach to dissect the optic nerve intracranially. Results: The model simulates standard microsurgical techniques using a variety of approaches to structures in and around the orbit and the optic nerve. Conclusions: This laboratory training model enables trainees to gain experience with an operating microscope, microsurgical instruments and orbital structures.