Chondrosarcoma in the body of the C2 vertebral axis.

Chondrosarcoma, a malignant bone tumor, is rarely encountered in the cervical spine. This article describes a patient whose neck pain and dysphagia were caused by an expansive, destructive lesion with calcification that was located in the body of the axis (C2 vertebra), the first time a chondrosarcoma has been reported in this location.

Single-stage planning for total cure of grade III-V brain arteriovenous malformations by embolization alone or in combination with microsurgical resection.

PURPOSE: There are no established guidelines for treatment of Spetzler-Martin grade III-V brain arteriovenous malformations (bAVMs). The purpose of this study is to report our institutional experience in total obliteration/eradication of grade III-V bAVMs by single-stage planning of embolization combined with microsurgical resection when necessary. METHODS: All patients harboring Spetzler-Martin (S-M) grade III-V bAVMs treated with single-stage planning between January 2006 and January 2018 were retrospectively reviewed. This treatment paradigm is applicable only to surgically accessible bAVMs and does not include deep-seated bAVMs. Indications for treatment, clinical presentation, imaging characteristics, and treatment outcomes were analyzed. Outcomes were assessed based on modified Rankin Scale. RESULTS: A total of 31 patients were identified. Seventeen patients (54.8%) presented with hemorrhage, 10 (32.3%) with seizures, 3 (9.7%) with headaches, and 1 (3.2%) with progressive neurological deficit. Based on S-M grading system, 25 patients (80.6%) harbored grade III bAVM, 5 patients had grade IV bAVMs (16.1%), and 1 patient (3.2%) had a grade V bAVM. There were no treatment-related complications in 24/31 (77.4%) patients. Of the total of seven patients with complications, four patients had clinical deterioration. The long-term (> 6-month), non-disabling morbidity (mRS ≤ 2) rate was 6.5%. The long-term, disabling morbidity rate was 3.2% with a mortality of 3.2%. Complete angiographic obliteration was achieved in 30/31 (96.8%) patients. CONCLUSION: Single-stage treatment strategy can be considered as an alternative to multistage embolization prior to surgery in grade III-V bAVMs. In this study, a high rate of total obliteration with relatively low rates of permanent morbidity and mortality was achieved.

Combined endovascular and surgical treatment of fusiform aneurysms of the basilar artery: technical note.

BACKGROUND: To present the combined treatment of fusiform basilar artery aneurysms consisting of a surgical posterior fossa decompressive craniectomy and ventriculoperitoneal (VP) shunt operation at the same sitting, before the endovascular procedure with telescopic stenting of the aneurysmatic vessel segment in four cases. METHODS: Combined treatment involving surgical procedure consisting of ventriculoperitoneal shunt placement for hydrocephalus and an occipital bone craniectomy and C1 vertebrae posterior laminectomy to decompress the posterior fossa in the same session. After surgery, the patients were loaded with acetylsalicylic acid and clopidogrel, and then the endovascular treatment was performed. RESULTS: All of the procedures were performed successfully without technical difficulty. The patients tolerated the procedures well and all cases showed remodelling with the overlapping stent technique. The patients were discharged home with baseline neurological situation and computed tomography (CT) angiography was performed at the 3rd month. CONCLUSION: This technique is a safer endovascular approach to treating symptomatic fusiform basilar artery aneurysms by protecting patients from both the haemorrhagic complications of anticoagulant therapy and thrombotic complications due to the interruption of anticoagulant therapy, while treating the hydrocephalus and compression by surgical means.

Osteointegration of a bisphenol-a-glycidyl-dimethacrylate composite and its use in anterior skull base defects: an experimental study in an experimental design model of cerebrospinal fluid leak.

OBJECT: Promising clinical results were reported in watertight closure of anterior skull base defects (ASBDs) with bisphenol-a-glycidyl-dimethacrylate (bis-GMA)-based materials to prevent the cerebrospinal fluid leaks. However, interrelation of these materials with surrounding bones in histologic level, referred to as the osteointegration, has not been reported in the anterior skull base. In addition, an illustrative case with an ASBD that was repaired using a bis-GMA composite has been presented. METHODS: Twenty New Zealand rabbits were divided into 4 groups: control and sham groups consisted of 2 and 6 rabbits, respectively. The "skull base defect" group (n = 6) underwent a unifrontal craniectomy and an iatrogenic ASBD followed by creating a dural defect to obtain a cerebrospinal fluid leak. Similar bony and dural defects were acquired in the "repair with bis-GMA based allograft" group (n = 6), but the bony defect was closed with bis-GMA-based allograft. RESULTS: All animals in the "skull base defect" group died in 3 weeks after surgery. There were no animal losses in the "repair with bis-GMA based allograft" group at the sixth month. Histologic evaluation revealed complete osteointegration of bis-GMA composite with surrounding bones. CONCLUSIONS: bis-GMA based allograft achieved a watertight repair of the ASBD. Histologic findings of this study showed that bis-GMA composite is a reliable material to be used in the closure of anterior skull base bony defects.

Transcranial superior orbitotomy for the treatment of intraorbital intraconal tumors: surgical technique and long-term results in single institute.

In this article, the authors are presenting their experience and the results with the surgical treatment of intraorbital intraconal tumors based on a review of 33 constitutive cases. Our data were evaluated in comparison to other major series, and possible factors that might influence surgical outcome and survival are discussed. Thirty-three patients diagnosed with intraorbital intraconal tumors between 1998 and 2009 were treated by transcranial approach. Of these patients, there were 14 males (42.4 %) and 19 females (57.8 %). The age ranged between 2 and 70 years (mean = 36 ± 16.6 years). The follow-up period ranged between 2 and 13 years (mean = 7.3 ± 3.2 years). The most common presenting symptoms were exophthalmus and decreased visual acuity, which was seen in 21 (63.6 %) and 19 patients (57.6 %), respectively. Total resection was achieved in 23 patients (69.7 %) while subtotal resection was done in ten patients (30.3 %). Cavernoma and optic nerve sheath meningioma were the most common histologic variants, which were found in 11 (33.3 %) and 10 (30.3 %) patients, respectively. In the long-term follow-up, 54.5 % of the patients showed total ophthalmologic improvement, 9.1 % showed partial improvement, 21.2 % demonstrated unchanged ophthalmologic status, and 15.2 % showed worse ophthalmologic outcome. Transcranial approach for the treatment of intraorbital intraconal tumors is an effective approach for the management of these pathologies. The effectiveness is clearly demonstrated by the clinical results and outcomes of these patients' groups.

Combined craniofacial resection of anterior skull base tumors: long-term results and experience of single institution.

In this article, the authors are presenting their experience and the results with combined craniofacial resection of anterior skull base tumors based on a review of 27 constitutive cases. Our data are evaluated in comparison to other major centers in other parts of the world, and possible factors that might influence surgical outcome and survival are discussed. Twenty-seven patients diagnosed with anterior skull base tumors between 1999 and 2009 were treated by combined craniofacial resection. Of these patients, there were 19 males (70, 3%) and eight females (29, 7%). The age ranged between 11 and 75 years (mean = 45.9 ± 17.6 years). The follow-up period ranged between 14 and 123 months (avarage = 74 months). The most common presenting symptoms were nasal obstruction and vision disturbance (11 patients for each -40.7%). Total resection was achieved in 24 patients (89%), while subtotal resection was done in three patients (11%). The most common complication was CSF fistule with rhinorrhea, which occurred in five patients (18.5%). Eight patients had recurrences at the time of this long-term follow-up. There were two mortalities in the early postoperative period and seven deaths in the long-term follow-up (overall mortality, 33.3%). The overall 5-year overall survival for all patients in our series was 70.4%. The 5-year overall survival was 62% for patients with malignant tumors and 100% for patients with benign tumors. Combined craniofacial resection of tumors of the anterior skull base is an effective approach for the management of these pathologies. The effectiveness is clearly demonstrated by the clinical results and outcomes of these patients' groups. The favorable prognosis is enhanced by significantly by total resection with negative tumor margins.

Comparison of two surgical techniques in Chiari Malformation Type 1 Patients: Duraplasty alone vs duraplasty with arachnoid dissection.

OBJECT: Optimal surgical technique to restore the cerebrospinal fluid flow through the foramen magnum remains to be debated in Chiari malformation type 1 (CM-1) patients. METHOD: This study included 46 patients with CM-1 who underwent surgical treatment by one of two methods: posterior fossa bone decompression (BD) with arachnoid preserving duraplasty (Group 1) and BD with duraplasty and arachnoid dissection (Group 2). Complaints of the patient population and neurological findings were assessed with Neck Disability Index (NDI) and Europe Quality of Life 5 Dimensions (EQ-5D) in pre- and postoperative periods. RESULTS: NDI and EQ-5D scores improved in overall patient population and in each individual surgical group. Both groups showed a significant decrease in size of syringomyelia cavity. Complications resulting in recurrent treatments and re-operations occurred in 15% of patients (n = 7); six of them were from Group 2. CONCLUSION: CM-1 patients benefit significantly from surgical treatment. Duraplasty should be included to surgical technique. Avoiding arachnoid dissection may lead to better results regarding complication rates.

Intraoperative Fluorescein Sodium Videoangiography in Intracranial Aneurysm Surgery.

OBJECTIVE: Fluorescein sodium (FNa) videoangiography (VA) was performed to evaluate blood flow within vessels and exclusion of the aneurysm after surgical clipping of intracranial aneurysms. The aim of this study was to report results of FNa-VA in a case series, including benefits and limitations of the technique, and compare intraoperative findings with postoperative cerebral angiography to assess reliability of FNa-VA. METHODS: The study included 64 aneurysms in 50 consecutive patients. Following clip ligation of the aneurysm, 100 mg of FNa was administered intravenously. The microscope light was switched to the FL560 integrated fluorescence module. Aneurysm sac, parent arteries, and perforating arteries were observed. RESULTS: FNa-VA promoted real-time assessment of the surgical field in three-dimensional view through the binoculars with good image quality. In 79.68% of aneurysms, FNa-VA confirmed satisfactory clip application, as FNa did not penetrate into the aneurysm. In 14.06% of aneurysms, a homogeneous yellow-green color change occurred, which was accepted as a false-positive sign. In 6.25% of aneurysms, FNa seeped into the aneurysm emitting a heterogeneous green signal, which slowly dispersed throughout the sac. Postoperative angiography revealed satisfactory results. Small neck remnants were present in 5 patients, and mild parent artery stenosis was found in 3 patients. No ischemic event occurred secondary to parent artery or perforating artery occlusion. CONCLUSIONS: FNa-VA adds greatly to the safety of surgical treatment of intracranial aneurysms, particularly in lesions situated in deep locations, by enabling real-time inspection, which facilitates safer manipulation and evaluation of structures in question.

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.

Intraosseous meningioma: a rare tumor reconstructed with porous polyethylene.

A 45-year-old woman described the pain and the swelling at the left frontoparietal region. No significant findings were noted on physical examination, except a heterogeneous palpable lesion at the described region. Computed tomographic scan revealed an expansive bone lesion with homogeneous density, whereas magnetic resonance imaging revealed similar findings with no contrast enhancement. The lesion was totally resected, and cranioplasty with a porous polyethylene sheet (Medpor Biomaterial; Porex Surgical, Newnan, GA) was achieved. Histopathologic examination revealed an intraosseous meningioma. As far as we know, this case is the first case, in which total excision of the interosseous meningioma is followed by reconstruction with Medpor.

Endoscopic endonasal anatomy and approaches to the anterior skull base: a neurosurgeon's viewpoint.

OBJECTIVES: The objective of this study was to review the endoscopic anatomy of the anterior skull base, defining the pitfalls of endoscopic endonasal approaches to this region. Recently, these approaches are gaining popularity among neurosurgeons, and the details of the endoscopic anatomy and approaches are highlighted from the neurosurgeons' point of view, correlated with demonstrative cases. MATERIALS AND METHODS: Twelve fresh adult cadavers were studied (n = 12). We used Karl Storz 0 and 30 degrees, 4 mm, 18- and 30-cm rod lens rigid endoscope in our dissections. After preparation of the cadaveric specimens, we approached the anterior skull base by the extended endoscopic endonasal approach. RESULTS: After resection of the superior portion of the nasal septum, bilateral middle and superior turbinates, and bilateral anterior and posterior ethmoidal cells, we could obtain full exposure of the anterior skull base. The distance between optic canal and the posterior ethmoidal artery ranged from 8 to 16 mm (mean, 11.08 mm), and the distance between posterior ethmoidal artery and the anterior ethmoidal artery ranged from 10 to 17 mm (mean, 13 mm). After resecting the anterior skull base bony structure and the dura between the 2 medial orbital walls, we could visualize the olfactory nerves, interhemispheric sulcus, and gyri recti. With dissecting the interhemispheric sulcus, we could expose the first (A1) and second (A2) segments of the anterior cerebral artery, anterior communicating artery, and Heubner arteries. CONCLUSIONS: This study showed that extended endoscopic endonasal approaches are sufficient in providing wide exposure of the bony structures, and the extradural and intradural components of the anterior skull base and the neighboring structures providing more controlled manipulation of pathologic lesions. These approaches need specific skill and learning curve to achieve more minimally invasive interventions and less postoperative complications.

Evaluation of Ideal Extent of Corpus Callosotomy Based on the Location of Intracallosal Motor Fibers.

BACKGROUND: The corpus callosotomy (CCT) has been reported as an effective procedure to alleviate drop attacks. However, the extent of CCT remains debatable. Classical studies suggest that motor fibers traverse mainly through the anterior half of the corpus callosum (CC), although recent diffusion tensor imaging studies described that motor fibers crossed the CC in a more posterior location, emphasizing the posterior midbody and the isthmus. METHODS: Cortical and subcortical structures were examined in 30 hemispheres prepared for white matter fiber dissection. Dissections were carried out under surgical magnification to trace fibers originating from the primary motor cortex and their course through the CC. The distance of the most anterior and posterior motor fibers to the tip of the genu were measured, and the extent of CCT enabling disconnection of all motor fibers was calculated. RESULTS: Motor fibers coursed through the posterior half of the CC in the majority of hemispheres, mainly locating in posterior midbody and the isthmus. Callosal fibers should be interrupted to an average of 61% ± 0.07% point of the CC to reach the anterior limit of motor fibers and to an average of 69% ± 0.07% point to include posterior limit of motor fibers. Motor fibers were extending until the posterior one third of the CC in 22 specimens. CONCLUSIONS: Anterior-half CCT did not include all motor fibers in any specimen. Anterior two thirds CCT disrupted all motor fibers in one fourth of the cases. Our findings suggest that an ideal CCT should extend to the posterior midbody and isthmus of the CC.

Hearing preserved traumatic delayed facial nerve paralysis without temporal bone fracture: neurosurgical perspective and experience in the management of 25 cases.

BACKGROUND: Delayed FNP due to HT is a rarely encountered clinical entity, and optimal treatment still remains to be elucidated. METHODS: Twenty-five patients with delayed traumatic FNP without TBF, who had serviceable hearing, were included in our study. Thirteen patients underwent surgical decompression, whereas 12 were managed medically depending on the ENoG findings, which were obtained within the first 3 weeks after the onset of the facial paralysis. Pre- and postmanagement evaluation of the FN function was graded according to HB grading scale. RESULTS: The mean follow-up period was 6.5 +/- 4.06 years. Complete or nearly complete recovery of FN function had occurred in 66.6% and 76.9% in medically and surgically treated groups, respectively. Most of the patients showed good outcome, and the presented data supports that the choice of treatment in patients with hearing preserved delayed traumatic FNP without TBF depends mainly on the ENoG findings. CONCLUSIONS: Although timing of surgery in traumatic delayed FNP remains to be elucidated, we think that surgical exploration should be considered if serial ENoG demonstrates more than 90% nerve degeneration.

Middle fossa approach: microsurgical anatomy and surgical technique from the neurosurgical perspective.

BACKGROUND: The purpose of this study was to call attention to the subtemporal approach directed through the petrous apex to the IAM. We studied the microsurgical anatomy of the middle floor to delineate a reliable angle between the GSPN and the IAM to precisely localize and expose the IAM from above. A new technique for the elevation of middle fossa floor in an anterior-to-posterior direction has also been examined in cadaveric dissections and performed in surgery. METHODS: The microsurgical anatomy of the middle fossa floor was studied in 10 adult cadaveric heads (20 sides) after meatal drilling on the middle fossa. Five latex-injected specimens were dissected in a stepwise manner to further define the microsurgical anatomy of the middle fossa approach. The middle fossa approach is illustrated in a patient for the decompression of the facial nerve to demonstrate the surgical technique and limitations of bone removal. RESULTS: Elevation of middle fossa dura in an anterior-to-posterior direction leads to early identification of the GSPN, where the nerve passes under V3. The most reliable and easily appreciated angle to be used in localizing the IAM is between the IAM and the long axis of the GSPN, which is approximately 61 degrees . Beginning drilling the meatus medially at the petrous ridge is safer than beginning laterally, where the facial and vestibulocochlear nerves become more superficial. The cochlea anteromedially, vestibule posterolaterally, and superior semicircular canal posteriorly significantly limit the bone removal at the lateral part of the IAM. CONCLUSIONS: The surgical technique for the middle fossa approach which includes an anterior-to-posterior elevation of middle fossa dura starting from the foramen ovale and uses the angle between the IAM and the long axis of the GSPN to localize the meatus from above may be an alternative to previously proposed surgical methods.

Reconstruction of growing skull fracture with in situ galeal graft duraplasty and porous polyethylene sheet.

OBJECTIVE: In growing skull fractures with large calvarial defects, it is difficult to use autografts for reconstruction and it requires alternative materials for cranioplasty. In this report, the authors describe their experience and introduce reconstruction of the growing skull fractures' defects with a porous polyethylene sheet (Medpor) and with a novel technique of duraplasty with in situ galeal graft, which avoid the potentially risky dissection and exposure of brain tissue. The goal of this study was to clarify effective surgical methods and to provide the rationale for these techniques. METHODS: We performed this technique on 8 patients with large calvarial defects resulting from growing skull fractures. The skin flap was retracted, leaving the galeal plane adherent to the underlying defect. After removing the bony edges and exposing the underlying retracted dural margins, duraplasty was performed by suturing the galeal tissue left in situ on the defect of the dural margins. Bone reconstruction was performed by placing porous polyethylene sheet (Medpor). CONCLUSIONS: Duraplasty with in situ galeal tissue is a simple, safe, and effective technique to reconstruct dural defects in growing skull fracture, which avoids the risky dissection of the brain tissue. Also, by using Medpor, growing skull fractures can be effectively reconstructed with good cosmetic results.

Posturographic examination of body balance in patients with Chiari type I malformation and correlation with the presence of syringomyelia and degree of cerebellar ectopia.

OBJECTIVES: We aimed to evaluate balance using the Tetrax Interactive Balance System (TIBS) in patients with Chiari type I malformation (CM-I) and to assess their fall risk with other clinical parameters. PATIENTS AND METHODS: This cross-sectional, prospective study was conducted at physical medicine and rehabilitation outpatient clinics and neurosurgery department of a university hospital between December 2013 and December 2014. The study included a total of 36 patients (31 females, 5 males; mean age 40.6±10.0 years; range, 18 to 60 years) with CM-I. Dynamic balance was assessed using the Berg Balance Scale (BBS), and posturographic examinations were performed using the TIBS. RESULTS: The mean Fall Risk Index (FI) value was 42.4±29.8 and the mean BBS score was 55.5±1.5. The most common complaints were neck pain (94.4%), headache (88.9%), paresthesia (86.1%), fatigue (83.3%), and vertigo (80.6%). The mean tonsillar herniation below the foramen magnum was 8.7±3.8 (mm). Of the patients, 15 (42.85%) had syringomyelia. The degree of tonsillar ectopia was statistically significantly lower in patients with syringomyelia (p<0.05). The BBS scores were near identical among the patients with or without syringomyelia, although the FI values were lower in the patients with syringomyelia. Comparing cerebellar ectopia ≤9 mm versus >10 mm, the FI values were slightly higher in the patients with ectopia >10 mm, although there was no statistically significant difference in the FI or BBS values. CONCLUSION: Our study results suggest that CM-I can decrease the body balance stability and, thus, increase the fall risk. Evaluation of balance in patients with CM using TIBS static posturography is a simple and effective technique.

Elevated cerebrospinal fluid and serum YKL-40 levels are not associated with symptomatic vasospasm in patients with aneurysmal subarachnoid haemorrhage.

YKL-40 is a newly discovered matrix protein that is thought to be released during the acute stages of inflammation. It has recently been speculated that YKL-40 may serve as a specific serological marker of neutrophil function at the site of tissue inflammation. Our aim was to determine whether the levels of YKL-40 in both the cerebrospinal fluid and sera of 22 patients with aneurysmal subarachnoid haemorrhage were associated with either vasospasm or outcome. The levels were also compared with those of 16 control patients with hydrocephalus. We found that patients with aneurysmal subarachnoid haemorrhage had significantly higher YKL-40 levels in both cerebrospinal fluid and serum than controls. However, elevated YKL-40 levels were not associated with symptomatic vasospasm or 6-month outcome. We show that elevated YKL-40 levels are not correlated with the severity of subarachnoid haemorrhage and cannot be used as a serological marker of inflammation in patients with an aneurysm rupture.

Expression of hypoxia inducible factor-1alpha in tumors of patients with glioblastoma multiforme and transitional meningioma.

Hypoxia-inducible factor-1 alpha (HIF-1alpha) is the major transcriptional factor involved in the adaptive response to hypoxia. The aim of this study was to assess HIF-1alpha in 22 patients with transitional meningioma (TM) and 26 patients with glioblastoma multiforme (GBM). HIF-1alpha was assessed using a commercially available enzyme-linked immunosorbent assay-based HIF-1 transcription factor assay. Levels of HIF-1alpha in TM and GBM were measured using optical density at 450nm, and median values were found to be 0.35 for TM and 0.37 OD for GBM, respectively. There was no statistically significant difference between the two types of tumor (p=0.264). These findings indicate that HIF-1alpha is elevated in both TM and GBM, suggesting that although hypoxia is one of the most important and powerful stimuli for HIF-1alpha elevation and consequently angiogenesis, other mechanisms may play roles in HIF-1alpha stimulation in benign brain tumors such as TM.

Surgical treatment of lesions involving the supplementary motor area: clinical results of 12 patients.

AIM: Surgical resection of lesions involving the dominant supplementary motor area (SMA) may result in immediate postoperative motor and speech deficits which in most cases are reversible.We report 12 patients with frontal lesions involving the SMA and aim to analyse the clinical data and the correlation of neurological deficit with the extent of SMA resection. MATERIAL AND METHODS: 12 patients (5M/7F, mean age 30.5) harbouring lesions involving the SMA who underwent surgery between 2002-2007 were evaluated retrospectively. Eloquent cortical areas were determined by functional MRI studies and/or invasive monitoring with subdural grids and depth electrodes and/or awake craniotomy with continuous intraoperative monitoring. RESULTS: The evaluation of postoperative MRI's revealed total and subtotal resection of the lesion in 9(75%) and 3(25%) patients respectively. The extent of SMA resection was complete in 5 patients (41,6%) and incomplete in 7 patients (58,3%). Immediately postoperatively, all patients where the resection of SMA was complete displayed the typical characteristics of SMA syndrome. The degree of deficits was consistent with the extent of the SMA resection in all patients. CONCLUSION: Proper diagnostic methods aiming to localise the sensorimotor area can minimize the risk of deficit in the surgical treatment of SMA lesions. The results suggest a relationship between the incidence of SMA syndrome and the extent of SMA resection.

Prenatal expressions of hyperpolarization-activated cyclic-nucleotide-gated channel (HCN) genes in dysplastic hippocampi in rats.

AIM: Hyperpolarization-activated cyclic nucleotide-gated (HCN or h-channel) channels mediate hyperpolarization-activating currents in the hippocampus and neocortex. The aim of this study is to present prenatal h-channel gene expressions (HCN1 and HCN2; HCN1-Entrez-Gene ID: 84390; HCN2- Entrez Gene ID: 114244) in dysplastic hippocampal pyramidal neurons induced by in utero irradiation in rats. MATERIALS AND METHODS: Time-pregnant Wistar albino rats were irradiated and the dysplastic hippocampus in their 2 month-old litters was studied. Gene expression was studied by RNA extraction and polymerase chain reaction methods. RESULTS: None of the rats showed seizure activity. mRNA levels of HCN1 and HCN2 genes were decreased especially in the CA1 and CA3 pyramidal neurons in the hippocampi of experimental rats; however, the differences were not significant compared to controls. In CA2, mRNA levels of both genes were increased and this rise did not reach significant level. The CA4 sub-region showed a different pattern of expression: HCN1 increased but HCN2 decreased insignificantly compared to controls. CONCLUSION: Our results demonstrated that dysplastic neurons showed decreased levels of mRNA expression of HCN1 and HCN2 genes, in particularly CA1 and CA3 pyramidal neurons. The rationale for how these changes contribute to epileptogenesis in dysplastic tissues still requires further studies.