Reza Dashti

Microsurgical management of pineal region lesions: personal experience with 119 patients

BACKGROUND Lesions of the pineal region are histopathologically heterogeneous but often accompanied with severe progression of clinical signs. Surgical treatment remains challenging because of the close vicinity of the deep venous system and the mesencephalo-diencephalic structures in this region. We present the surgical approaches and techniques in a consecutive series of 119 patients treated by the senior author (J.H.) between 1980 and 2007 at 2 different neurosurgical university centers in Kuopio and Helsinki, Finland. METHODS Of the included patients, 107 (90%) presented with pineal region tumors and 12 (10%) with vascular malformations. The ITSC route was used for removal of the lesion in 111 (93%) patients and the OIH approach in 8 (7%) patients. All except one patient were operated on in a sitting position. RESULTS We reviewed all clinical data and radiographic images and analyzed all surgical videos. The pineal lesions were removed completely in most cases (88%). There was no surgical mortality. Twenty-two (18%) of the patients had complications in the postoperative period; these included 1 epidural hematoma, 9 transient Parinaud syndrome, 2 meningitis, 3 wound infections, 2 transient memory disturbances, 2 mild hemiparesis, 1 CSF fistula, and 2 cranial nerves palsies (IV and VI). During a 3.5-year follow-up, 12 patients with malignant lesions died; all patients with benign tumors survived. CONCLUSIONS The ITSC route is a safe and effective surgical approach, associated with low morbidity, complete lesion removal, and definitive histopathologic diagnosis. Considering risk vs benefit, we therefore believe that the surgical treatment can be offered in most cases as the first treatment option for pineal tumors.

Acute ethanol intoxication in a model of traumatic brain injury: the protective role of moderate doses demonstrated by immunoreactivity of synaptophysin in hippocampal neurons.

Abstract Although ethanol intoxication is reported to be a complicating factor in traumatic brain injury, some recent studies are indicating its possible protective role especially at lower doses. Ethanol inhibition of NMDA-mediated excitotoxicity which predominates at lower doses is believed to be responsible for this protection. The aim of this study was to demonstrate this neuroprotective role of alcohol using immunoreactivity for synaptophysin as an indirect marker for severity of injury. Acute ethanol intoxication at moderate doses was performed 2 h prior to trauma. Severe traumatic brain injury was administrated using an impact acceleration model in Sprague–Dawley rats. At post-traumatic 48th hour, immunorectivity for synapthophysin in the rat hippocampi was evaluated under light microscopy. According to our results there were slight increases in immunoreactivity for synaptophysin in the stratum oriens and striatum radiatum of CA1 subfield of hippocampus when ethanol was administered prior to trauma comparing to moderate increase in the trauma-only group. On the other hand vacuolar degeneration and red neuron formation was more prominent in the pyramidal cell layer of CA1 and CA3 when ethanol was not administered. Ethanol may have a neuroprotective role when administered at moderate doses prior to traumatic brain injury. This effect of ethanol may primarily be due to inhibition of NMDA receptors.

Hydrocephalus and chronically increased intracranial pressure in achondroplasia

Abstract Two achondroplastic children with ventriculomegaly are reported. The patients had no signs of increased intracranial pressure, but in one blindness had previously been detected by the parents. Neuroradiological examinations showed ventriculomegaly in both. Intracranial pressure remained at high levels (20–55 mmHg) preoperatively; ventriculo-peritoneal shunting was performed in both cases, and postoperatively levels fell to normal (5–16 mmHg). The need for the treatment of ventriculomegaly seen in achondroplastic children is analyzed on the basis of these two patients, with a brief review of literature.

Microscope Integrated Indocyanine Green Video-Angiography in Cerebrovascular Surgery

Microscope integrated indocyanine green video-angiography (ICG-VA) is a new technique for intraoperative assessment of blood flow that has been recently applied to the field of Neurosurgery. ICG-VA is known as a simple and practical method of blood flow assessment with acceptable reliability. Real time information obtained under magnification of operating microscope has many potential applications in the microneurosurgical management of vascular lesions. This review is based on institutional experience with use of ICG-VA during surgery of intracranial aneurysms, AVMs and other vascular lesions at the Department of Neurosurgery at Helsinki University Central Hospital.

Concomitant fracture of bilateral occipital condyle and inferior clivus: what is the mechanism of injury?

With the routine use of multi-slice high resolution computed tomography, increasing number of occipital condyle fractures have been reported in the last decade. The authors report a very rare case of bilateral occipital condyle fracture complicated by the fracture of the inferior clivus and discuss the possible mechanisms of injury.

Low-profile 1-piece bifrontal craniotomy for anterior skull base approach and reconstruction

Objective: The anterior skull base is a location of many pathologic lesions. These pathologic lesions are treated by bifrontal craniotomy and anterior skull base approach, either primarily or combined with facial osteotomies. To obtain wide exposure, low-profile craniotomies are preferred. In this article, we attempt to describe our own technique of frontal craniotomy for anterior skull base approach. In this technique, the frontal bone, frontal sinus, and the superior supraorbital bar are elevated in en bloc fashion. Methods: Bicoronal skin incision is followed by dissection and retraction of the skin flap in the epigaleal plan. The pericranial galeal flap is dissected separately in subperiosteal fashion until the superior orbital rim. After dissection and retraction of the tip of the temporal muscles, bilateral pterional key burr holes and 1 or 2 parasagittal burr holes are opened. The sagittal burr hole(s) is placed in the point where the upper horizontal surface of the frontal bone slopes vertically downward the forehead. With the craniotome rotating tip (Midas F2/8TA23, Medtronic Inc, Ft Worth, TX), bone cut is made between the pterional key burr holes, passing through the superior orbital bar and the anterior wall of the frontal sinus. To minimize the brain retraction, the operating microscope is placed beside the head, and exposure from the lateral view angle is obtained. Reconstruction of the defect is performed by using pericranial galeal flap and/or Cortoss (Orthovita, Malvern, PA). Results: With this approach, wide exposure of the anterior skull base pathologic lesions was achieved with minimal brain retraction. In the postoperative period, patients tolerated this approach well with favorable functional and cosmetic outcomes. No infections or adverse effects related to this technique or Cortoss were observed. Conclusions: Anterior skull base pathologic lesions can be widely exposed by low-profile bicoronal craniotomy and anterior skull base approach with minimal brain retraction. This wide exposure allows us to gain more control of the pathologic lesion with better resection and reconstruction, reflected on the prognosis of the patients.

Aneurysmal frontal bone cyst in a child with history of acute lymphoblastic leukemia: a case of rare location and history.

Authors present an 11-year-old female admitted with a 3-month history of painless forehead mass. The mass was located in the left frontal area and was pronounced on inspection and palpation. Neurologic examination revealed no abnormalities. The patient was diagnosed for acute lymphoblastic leukemia 5 years ago and had been treated. The patient was under observation by the pediatric oncology clinic with remission state since 3 years. Brain computed tomography and magnetic resonance imaging revealed a cystic bone lesion in the right frontal bone. A preoperative diagnosis of myeloproliferative disorder was made and it was surgically resected and cranioplasty with porous polyethylene sheets (Medpor, Porex Surgical Inc, GA) was performed in the same stage. Pathologic examination revealed an aneurysmal bone cyst. The patient recovered with complete resolution of symptoms. Although rare lesions, aneurysmal bone cysts must be considered in the differential diagnosis of calvarial mass lesions.

Emergence of a high-grade sarcoma in a recurrent meningioma: Malignant progression or collision tumor?

Anaplastic meningiomas that resemble sarcomas often reveal clues to their meningothelial differentiation or develop in a plausible setting that confirms their meningothelial origin. Malignant mesenchymal neoplasms without obvious evidence of meningothelial differentiation or origin are more likely to be true primary or metastatic sarcomas. Because of their clinical and biological differences, it is important to distinguish anaplastic meningioma from a sarcoma. We present a 67-year-old woman with multiple meningiomas, who developed a high-grade spindle cell tumor 6 months after the resection of a World Health Organization grade I meningioma. It was not clear whether this tumor represented a malignant transformation of meningioma or a primary sarcoma. Malignant transformation of a meningioma is exceptional within this short period and a coexisting sarcoma and meningioma are equally uncommon. Even though these malignant neoplasms are rare in general, they appear to be more prevalent in patients with multiple meningiomas including those with neurofibromatosis type 2.

Terminal syringomyelia mimicking an intramedullary tumor: case report.

In this report, the authors present a 14-year-old male patient admitted with progressive paraparesis and urinary incontinence that developed in a 3-month period. Thoracolumbar MRI revealed an intramedullary lesion starting from the level of the T10 vertebra and extending to fill the sacral spinal canal. Based on the radiological findings an intramedullary tumor was suspected. Exploratory operation with right L5 hemilaminectomy was done and the intraoperative finding was syringomyelia which was punctured with releasing of the tethered cord. The patient was followed for 3 years with clinical and radiological regression of the pathology and no symptoms and sings have remained. Syringomyelia can mimic intramedullary tumors clinically and radiologically. That is why it is useful to consider exploratory hemilaminectomy to confirm diagnosis.

Lateral tethering intraspinal lipoma with scoliosis

The authors present an unusual case of an intradural lipoma at the thoracolumbar level causing lateral tethering of the spine, with complicated scoliosis. A 6-year-old girl was admitted with progressive change in posture detected by her parents. Thoracolumbar scoliosis was detected by physical examination and X-ray studies. Spinal magnetic resonance imaging revealed an intradural lipoma and right lateral tethering of the spine at the upper lumbar level. After surgical release of lateral tethering and resection of the lipoma, fusion was performed by the orthopedic surgery team. Radiological and intraoperative findings of this extremely rare case are discussed.