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.

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.

[Cerebral infarction due to traumatic carotid artery dissection: case report and review of current management]. / Travmatik karotis arter diseksiyonuna bagli serebral enfarkt: Olgu sunumu ve güncel yaklasimin gözden geçirilmesi.

With the advent of improved neuroradiological methods, it has been determined that frequency of traumatic carotid artery dissections is higher than previously observed. Since delayed neurological deficits may develop in some asymptomatic undiagnosed cases, it is essential to consider the possibility of the carotid artery dissection and evaluate it properly in suspicious cases. In this article, a case of internal carotid artery dissection and subsequent cerebral infarction following a motor vehicle accident is presented. Pathogenesis, clinical features, diagnostic method choices and treatments in this rare but severe condition are discussed in light of the relevant literature in order to convey current knowledge.

Intrasacral extradural arachnoid cysts.

Three patients presented with rare intrasacral extradural arachnoid cysts manifesting as sensory deficiencies and pain in the lower extremities. Magnetic resonance imaging with various sequences identified the cysts. Two patients underwent surgery via laminectomy of the sacrum for cyst exploration and disconnection of the cyst with the dural theca. Postoperative outcome was favorable in these two patients. Intrasacral extradural arachnoid cyst should be considered in the differential diagnosis of low back pain.

Hereditary neuropathy with liability to pressure palsies in a Turkish patient (HNPP): a rare cause of entrapment neuropathies in young adults.

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant nerve disease usually caused by 1,5 Mb deletion on chromosome 17p11.2.2-p12, the region where the PMP-22 gene is located. The patients with HNPP usually have relapsing and remitting entrapment neuropathies due to compression. We present a 14-year-old male who had acute onset, right-sided ulnar nerve entrapment at the elbow. He had electrophysiological findings of bilateral ulnar nerve entrapments (more severe at the right side) at the elbow and bilateral median nerve entrapment at the wrist. Genetic tests of the patient demonstrated deletions in the 17p11.2 region. The patient underwent decompressive surgery for ulnar nerve entrapment at the elbow and completely recovered two months after the event. Although HNPP is extremely rare, it should be taken into consideration in young adults with entrapment neuropathies.

An upper thoracic spinal cord tumor presenting as hemifacial hyperhidrosis.

BACKGROUND: Hyperhidrosis as the sole presenting symptom of an upper thoracic intramedullary tumor has never been reported in the English literature. CASE DESCRIPTION: A 17-year-old boy presented with a long history of hemifacial flushing and hyperhidrosis on the left side of his face and neck. The MRI revealed a large spinal cord tumor at the T1-T2 levels. The patient underwent total excision of the intramedullary tumor via a posterior myelotomy. The histopathological diagnosis was low-grade astrocytoma. The symptoms resolved immediately after the surgery and did not return during the follow-up period of 9 months. CONCLUSIONS: We suggest that sympathetic irritation on the left side is the mechanism behind this clinical presentation. Its unusual presentation and lack of motor and sensory deficits resulted in delayed diagnosis of this potentially disabling lesion. When autonomic dysfunction of the face and neck is encountered, in addition to the cranial and cervical regions, the upper thoracic levels should be investigated using MRI.

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.

Giant subdural empyema in a child: a case report.

An unusual case of a giant (8 x 6 x 6 cm) frontoparietal SDE of Streptococcus pneumoniae in a 17-month-old child is reported. The initial diagnosis was made with emergency CT. The purulent material was removed via a frontoparietal craniotomy. A series of postoperative MR imaging showed the gradual reduction in size of the lesion, although collapsed capsule, fibrous thickening of meningeal structures and associated displacement of the underlying brain persisted. The child was symptom-free in a follow-up period of 15 months. This case showed that SDE may reach a giant size and thus may mimic an intra-axial lesion; the coronal MR imaging is a more reliable diagnostic tool than the emergency axial CT in giant SDE of upper convexity localization, and the clinical improvement may be more impressive than the radiological changes.

Simulation of surgery for craniosynostosis: a training model in a fresh cadaveric sheep cranium. Technical note.

The authors present a training model in sheep crania that allows residents in neurosurgery and plastic surgery to practice the frontoorbital remodeling procedure used in the surgical correction of simple craniosynostoses such as plagiocephaly, trigonocephaly, and brachiocephaly. The model comprises a three-step approach: subperiosteal and subperiorbital dissection; elevation of the bifrontal bone flap and the supraorbital bar; and finally, frontoorbital remodeling. The authors conclude that this training model, based on the use of cadaveric sheep crania, represents a fairly useful method to accustom trainees to the required surgical techniques and simulates well the steps of standard pediatric and adult craniofacial surgery for simple craniosynostosis.

Microneurosurgical training model in fresh cadaveric cow brain: a laboratory study simulating the approach to the circle of Willis.

BACKGROUND: Residents of neurosurgery need many years to develop microneurosurgical skills, and laboratory training models are essential for developing and refining surgical skills before clinical application of microneurosurgery. A simple simulation model is needed for young residents to learn how to handle microneurosurgical instruments, and to perform safe dissection of intracranial vessels and nerves. METHODS: The material consists of a 2-year-old fresh cadaveric cow cranium. A 4-step approach was designed to dissect the internal carotid artery and its proximal branches, the optic nerve, the optic chiasm, and the pituitary stalk. RESULTS: The model simulates standard microneurosurgery using a variety of approaches to vessels and neural structures in and around the circle of Willis of the human brain. CONCLUSION: The cadaveric cow brain, besides being cost-effective, represents a fairly useful method to accustom residents of neurosurgery, especially junior residents, to dissecting intracranial vessels and nerves, and it simulates intracranial microneurosurgical procedures performed in the human brain.

Neuroprotective effects of N-acetylcysteine on experimental closed head trauma in rats.

N-acetylcysteine (NAC) is a precursor of glutathione, a potent antioxidant, and a free radical scavenger. The beneficial effect of NAC on nervous system ischemia and ischemia/reperfusion models has been well documented. However, the effect of NAC on nervous system trauma remains less understood. Therefore, we aimed to investigate the therapeutic efficacy of NAC with an experimental closed head trauma model in rats. Thirty-six adult male Sprague-Dawley rats were randomly divided into three groups of 12 rats each: Group I (control), Group II (trauma-alone), and Group III (trauma+NAC treatment). In Groups II and III, a cranial impact was delivered to the skull from a height of 7 cm at a point just in front of the coronal suture and over the right hemisphere. Rats were sacrificed at 2 h (Subgroups I-A, II-A, and III-A) and 12 h (Subgroups I-B, II-B, and III-B) after the onset of injury. Brain tissues were removed for biochemical and histopathological investigation. The closed head trauma significantly increased tissue malondialdehyde (MDA) levels (P < 0.05), and significantly decreased tissue superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities (P < 0.05), but not tissue catalase (CAT) activity, when compared with controls. The administration of a single dose of NAC (150 mg/kg) 15 min after the trauma has shown protective effect via decreasing significantly the elevated MDA levels (P < 0.05) and also significantly (P < 0.05) increasing the reduced antioxidant enzyme (SOD and GPx) activities, except CAT activity. In the trauma-alone group, the neurons became extensively dark and degenerated into picnotic nuclei. The morphology of neurons in the NAC treatment group was well protected. The number of neurons in the trauma-alone group was significantly less than that of both the control and trauma+NAC treatment groups. In conclusion, the NAC treatment might be beneficial in preventing trauma-induced oxidative brain tissue damage, thus showing potential for clinical implications.

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.

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 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.

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.

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 x 7 x 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.

[Pediatric head injuries: a retrospective analysis of 280 patients.]. / Çocukluk çagi kafa travmalari: 280 olgunun retrospektif degerlendirmesi.

BACKGROUND: To assess etiological factors, clinical features, radiological findings and recovery rates in pediatric head injuries. METHODS: Patients (n =280) with head injuries (age range: 0 - 16 years) hospitalized in Trakya University Department of Neurosurgery between January 1995 and 2004 were analyzed statistically. RESULTS: According to Glasgow Coma Scale (GCS) the patients had minor (GCS: 13- 15 ; 70.1% ), moderate (GCS: 9- 12; 17,1% ), or severe (GCS: 3 to 8; 6,8% ). head injuries The most common etiological factor was fall from a height (34,3%); and the most frequently associated injury was extra-spinal skeletal injury (12,9%). Fifty-one patients (18,2%) underwent neurosurgical operation. 87.5% of them recovered completely, while 12,5% showed partial recovery or died, as graded by Glasgow Outcome Scale (GOS). There was a moderately strong correlation between initial GCS and GOS (r=0,53, p=0,01). CONCLUSIONS: Nearly half of the pediatric head injuries were caused by falls with good prognoses. In the school age, motor vehicle accident (MVA) was the most frequent trauma type. MVA was the most serious type of trauma as demonstrated by its low GCS and GOS scores. Polytraumas, subdural hematomas, cerebral contusions, subarachnoid or intracerebral hemorrhages, cerebral edemas, diffuse axonal injuries, and any cranial lesion which required surgery were found to be related with poor prognosis.

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 patient's 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.

Surgical management of combined stab injury of the spinal cord and the aorta--case report.

A 32-year-old man presented with a combined penetrating stab injury of the spinal cord and the aorta caused by a knife wound in his back at the low thoracic level. The knife had broken, and part of the blade had been retained in the wound, passing through the spinal canal and into the aortic lumen. The patient was treated in two steps: the aorta was repaired by a thoracotomy, then spinal exploration was carried out through a laminectomy. Because of the tamponade effect of the foreign body, it was necessary to delay removal of the blade until vascular control had been achieved. Any sign of a penetrating body passing through the spine should suggest careful evaluation to detect any visceral injury, and multidisciplinary treatment should be planned.

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.