Microsurgical anatomy and surgical exposure of the cerebellar peduncles.

A better understanding of the surgical anatomy of the cerebellar peduncles in different surgical approaches and their relationship with other neural structures are delineated through cadaveric dissections. We aimed to revisit the surgical anatomy of the cerebellar peduncles to describe their courses along the brain stem and the cerebellum and revise their segmental classification in surgical areas exposed through different approaches. Stepwise fiber microdissection was performed along the cerebellar tentorial and suboccipital surfaces. Multiple surgical approaches in each of the cerebellar peduncles were compared in eight silicone-injected cadaveric whole heads to evaluate the peduncular exposure areas. From a neurosurgical point of view, the middle cerebellar peduncle (MCP) was divided into a proximal cisternal and a distal intracerebellar segments; the inferior cerebellar peduncle (ICP) into a ventricular segment followed by a posterior curve and a subsequent intracerebellar segment; the superior cerebellar peduncle (SCP) into an initial congregated, an intermediate intraventricular, and a distal intramesencephalic segment. Retrosigmoid and anterior petrosectomy approaches exposed the junction of the MCP segments; telovelar, supratonsillar, and lateral ICP approaches each reached different segments of ICP; paramedian supracerebellar infratentorial, suboccipital transtentorial, and combined posterior transpetrosal approaches displayed the predecussation SCP within the cerbellomesencephalic fissure, whereas the telovelar approach revealed the intraventricular SCP within the superolateral recess of the fourth ventricle. Better understanding of the microsurgical anatomy of the cerebellar peduncles in various surgical approaches and their exposure limits constitute the most critical aspect for the prevention of surgical morbidity during surgery in and around the pons and the upper medulla. Our findings help in evaluating radiological data and planning an operative procedure for cerebellar peduncles.

Role of the MyD88 Dependent Pathway in Degenerative Disc Disease.

AIM: To define the substantial role of the TLR4 signaling pathway in the MyD88-dependent pathway, and to evaluate the results of TLR4 activation in nucleus pulposus cells. Moreover, we aim to associate this pathway with intervertebral disc degeneration and magnetic resonance imaging (MRI) findings. Additionally, the clinical differences among patients and the effects of their drug use will be evaluated. MATERIAL AND METHODS: Eighty-eight adult male patients with lower back pain and sciatica underwent MRI studies, which showed degenerative changes. Disc materials were obtained intraoperatively from those who underwent surgery for lumbar disc herniation. These materials were kept in freezers at ?80°C without any delay. Then, the collected materials were examined using enzyme-linked immunosorbent assays. RESULTS: Modic type I degeneration had the highest values of all markers, whereas Modic type III degeneration had the lowest values. These results verified that this pathway plays an active role in MD. Moreover, contrary to the current knowledge on which Modic type inflammation is more dominant, we showed that it is the Modic type I phase. CONCLUSION: The most intense inflammatory process was observed in Modic type 1 degeneration, and the MyD88-dependent pathway was found to play a key role. While the most intense molecular increase was detected in Modic type 1 degeneration, the lowest levels were observed in Modic type III degeneration. It has been observed that the use of nonsteroidal anti-inflammatory drugs affects the inflammatory process through the MyD88 molecule.

Can TRIF/TICAM-1 Dependent Pathway be Target Pathway in Lumbar Intervertebral Disc Degeneration?

AIM: To elucidate the role of the TIR-domain-containing adaptor-inducing interferon-? (TRIF) dependent pathway in intervertebral disc degeneration (IVD). MATERIAL AND METHODS: A total of adult male patients with low back pain (LBP) (+/- radicular pain) were further evaluated by magnetic resonance imaging (MRI) with surgical indication for microscopic lumbar disc herniation (LDH). Preoperatively, patients were classified according to Modic Changes (MC), nonsteroidal anti-inflammatory drugs (NSAIDs) use, and the presence of radicular pain in addition to the LBP. RESULTS: The age of the 88 patients ranged from 19 to 75 years (mean: 47.3 ± 19.6 years). Twenty eight of the patients were evaluated as MC I (31.8%), 40 as MC II (45.4%), and 20 as MC III (22.7%). The majority of patients (81.8%) had radicular LBP, while 16 patients (18.1%) had only LBP. Predominantly, 55.6% of all patients were taking NSAIDs. Levels of all adaptor molecules were highest in the MC I group and lowest in the MC III group. The levels of IRF3, TICAM1, TICAM2, NF-kB p65, TRAF6, and TLR4 were significantly increased in the MC I group compared to the MC II and MC III groups. The variations of the individual adaptor molecules showed no statistically significant difference in the use of NSAIDs and radicular LBP. CONCLUSION: As a result of the impact assessment, the current study clearly demonstrated for the first time that the TRIFdependent signalling pathway plays a crucial role in the degeneration process in human lumbar intervertebral disc specimens.

Factors Affecting Seizure Outcomes After Surgery for Cavernoma Related Epilepsy.

AIM: To present one of the largest retrospective cavernoma related epilepsy (CRE) studies which include divergent supratentorial locations operated and followed up at least 2 years. We also investigated the factors affecting the seizure outcome. MATERIAL AND METHODS: This study includes a total of 56 patients with drug-responsive (n=40) and drug-resistant (n=16) CRE who underwent resective surgery. Age at seizure onset, age at surgery, gender, duration of epilepsy, seizure frequencies/type before and after treatment, EEG and brain MRI findings, prescribed AEDs, preoperative and post-operative neurological status, histopathological diagnosis, post-operative seizure outcomes and surgical information were documented. RESULTS: The average follow-up period was 69.6 months (range 24-216 months). The seizure outcome was assessed according to Engel?s classification at the last follow-up. Engel class I was achieved in 53 patients (95%); there was one patient at class II and two patients at class III. All patients in the drug-responsive group were at Engel class I after the surgery, while all patients at Engel classes II and III were in the drug-resistant patient group. This clearly shows that there were better outcomes in DRP group (p < 0.01). Neither the locations of cavernomas nor the duration of epilepsy had any impact on seizure outcome (p > 0.05). CONCLUSION: An earlier surgical intervention may prevent the patients from becoming drug-resistant such that their chances of being seizure free after surgery increase.

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.

A novel insight into differential expression profiles of sporadic cerebral cavernous malformation patients with different symptoms.

Cerebral cavernous malformation (CCM) is a vascular lesion of the central nervous system that may lead to distinct symptoms among patients including cerebral hemorrhages, epileptic seizures, focal neurologic deficits, and/or headaches. Disease-related mutations were identified previously in one of the three CCM genes: CCM1, CCM2, and CCM3. However, the rate of these mutations in sporadic cases is relatively low, and new studies report that mutations in CCM genes may not be sufficient to initiate the lesions. Despite the growing body of research on CCM, the underlying molecular mechanism has remained largely elusive. In order to provide a novel insight considering the specific manifested symptoms, CCM patients were classified into two groups (as Epilepsy and Hemorrhage). Since the studied patients experience various symptoms, we hypothesized that the underlying cause for the disease may also differ between those groups. To this end, the respective transcriptomes were compared to the transcriptomes of the control brain tissues and among each other. This resulted into the identification of the differentially expressed coding genes and the delineation of the corresponding differential expression profile for each comparison. Notably, some of those differentially expressed genes were previously implicated in epilepsy, cell structure formation, and cell metabolism. However, no CCM1-3 gene deregulation was detected. Interestingly, we observed that when compared to the normal controls, the expression of some identified genes was only significantly altered either in Epilepsy (EGLN1, ELAVL4, and NFE2l2) or Hemorrhage (USP22, EYA1, SIX1, OAS3, SRMS) groups. To the best of our knowledge, this is the first such effort focusing on CCM patients with epileptic and hemorrhagic symptoms with the purpose of uncovering the potential CCM-related genes. It is also the first report that presents a gene expression dataset on Turkish CCM patients. The results suggest that the new candidate genes should be explored to further elucidate the CCM pathology. Overall, this work constitutes a step towards the identification of novel potential genetic targets for the development of possible future therapies.

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.

Dysembryoplastic neuroepithelial tumors and gangliogliomas: clinical results of 52 patients.

PURPOSE: Dysembryoplastic neuroepithelial tumors (DNET) and gangliogliomas (GG) are generally associated with epilepsy in young patients. Presurgical work-up and postsurgical results vary from center to center. Seizures are commonly focal with secondary generalization, and surgical treatment is often effective. METHODS: Twenty-eight patients with DNET and 24 patients with GG were eligible for this retrospective study. The authors present clinical, radiological, and pathological characteristics and seizure outcome of 52 patients histopathologically diagnosed with either a DNET or a GG. RESULTS: Characteristically the majority of the tumors showed hypointensity on T(1)-weighted images and increased signal intensity on both T(2)-weighted and FLAIR images. At the last follow-up (mean 54.3 months), overall favorable seizure outcome was 94.2% (n = 49). Twenty-six (92.8%) patients with DNET and 21 (87.5%) patients with GG were seizure free. Complete drug withdrawal was achieved in 26 (50%) patients. Shorter duration of epilepsy (p = 0.02), absence of status epilepticus (p = 0.01), absence of edema on MRI (p = 0.03), absence of seizure within the first month of surgery (p = 0.002), and total resection (p = 0.00001) were associated with favorable outcome with respect to seizure. CONCLUSIONS: Our results indicate that a prompt diagnosis and total resection with additional adjacent structures or cortices when feasible are associated with a high epilepsy cure rate. Not only children but also adults benefit from surgical treatment. Although radiological features of DNETs or GGs are helpful, no definitive differences were found between the two types of tumors. Thus, clinical, radiological, and histopathological findings have to be considered together.

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.

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.

Endoscopic anatomy and approaches of the cavernous sinus: cadaver study.

OBJECTIVE: The objectives of this study were to recognize the endoscopic anatomy of the cavernous sinus and to understand the standard, purely endoscopic endonasal approaches to this anatomic structure. This basic information will facilitate our surgical procedures and decrease the rate of surgical complications. MATERIALS AND METHODS: Seven fresh adult cadavers were studied bilaterally (n = 14). We used Karl Storz 0 and 30 degrees , 4 mm, 18 cm and 30 cm rod lens rigid endoscope in our dissections. After cadaver preparation, extended endoscopic endonasal approaches were performed to access the cavernous sinus. RESULTS: In the seven cadavers, the cavernous sinus and superior orbital fissure, on both sides, were widely exposed with extended endoscopic endonasal approach. The antero-inferior portion of the cavernous sinus was exposed by removing the superior and the middle turbinates and the posterior ethmoidal cells (extended endoscopic endonasal transsphenoidal approach); the whole lateral wall of the cavernous sinus was exposed by removing the anterior and the posterior ethmoidal cells (endonasal ethmoido-pterygo-sphenoidal approach: far lateral); and the medial wall of the cavernous sinus was exposed by introducing the 30 degrees endoscope from the contralateral nostril (contralateral endoscopic endonasal transsphenoidal approach). According to the neurovascular architecture, the lateral wall of the cavernous sinus is divided into the superior triangular area, the superior quadrangular area and the inferior quadrangular area. This division can facilitate understanding of the anatomic relations of the cavernous sinus from the endoscopic view. CONCLUSION: Knowledge of the anatomy of the cavernous sinus obtained with an endoscopic view of cadaver dissections is an essential step in the learning curve of endoscopic skull base surgery, and is important for endoscopic treatment of various pathologies in this region. In this anatomic study, we reviewed the approaches to the cavernous sinus with an endoscopic view and identified the neurovascular relations. This approach will help in performing safer and minimally invasive surgery.

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.

Surgical morbidity of invasive monitoring in epilepsy surgery: an experience from a single institution.

AIM: This paper aimed to provide information related to surgical and neurological complications encountered following intracranial electrode placements in patients with medically intractable epilepsy. MATERIAL AND METHODS: Retrospective review of 70 patients with either subdural grid/strip or depth electrode implanted between 2004 and 2009 at the Epilepsy Unit in Cerrahpasa Medical Faculty. RESULTS: A total of 276 electrode implantations were performed in 70 patients. There were no deaths related to implantation. The occurrence of infection and intracranial hematoma were found to be 1.4 and 1.4%, respectively. A total of 1 patient (1.4%) showed transient neurological complications. The rate of overall morbidity including neurological complications was found to be 4.2% (n=3). CONCLUSION: Based on our experience, intracranial electrode implantation is an effective and safe method with extremely low morbidity rate, especially in experienced hands.

Extended endoscopic endonasal approach to the anterior cranio-vertebral junction: anatomic study.

OBJECTIVE: Our aim in this study was to identify the endoscopic anatomy of the anterior cranio-vertebral junction to be able to perform minimal invasive endoscopic surgical procedures to this region (such as dens resection) safely with better postoperative performance of the patients. MATERIAL AND METHODS: Five fresh adult cadavers were studied (n=5). We used Karl Storz 0 and 30 degree, 4mm, 18 cm and 30 cm rod lens rigid endoscope in our dissections. After cadaveric specimen preparation, we approached the anterior cranio-vertebral junction by binostril extended endoscopic endonasal approach. RESULTS: The cranio-vertebral junction was located by orientating the endoscope between -10 to +10 degrees. The rhinopharynx was widely exposable after resection of the vomer. The safe lateral limit of this approach was the occipital condyles and foramen lacerum. We could perform odontoid process resection with a pure endoscopic endonasal approach. CONCLUSION: Our anatomic study offered the facility to learn the endoscopic anatomy of the anterior cranio-vertebral junction and understand the appropriate approaches to this region. Our approach is appropriate for treatment of some pathologies of this region, with less invasiveness compared to the traditional transoral approach.

Endoscopic endonasal transsphenoidal approach to the sellar region: results of endoscopic dissection on 30 cadavers.

AIM: To recognize the endoscopic anatomy of the surgical corridor along the nasal cavity, sphenoidal sinus and the sellar area to delineate the pure endoscopic endonasal transsphenoidal approach (EETSA) to the region of the pituitary gland. MATERIAL AND METHODS: The endoscopic anatomy of the nasal cavity, sphenoid sinus and the sellar region was studied in 30 fresh cadavers (mean age 42.1 / range 18-66) and dissections were performed in a stepwise manner to simulate EETSA to the sellar region. RESULTS: The sphenoid ostium, located 14.9 mm superior to the choana, was identified at the midpoint between the nasal septum and the superior turbinate in 23 specimens. The shape of the sphenoid ostium was linear (35%), fusiform (30%), oval(22%) or circular (13%). The mean width of the pituitary gland was 14.3 mm and the average minimum distance between the internal carotid arteries on both sides ranged between 13 to 22 mm. Following total hypophysectomy in 12 specimens, the width and length of diaphragma sellae was measured 10.83 and 5.83 mms respectively. CONCLUSION: This study documents that variations are common in nasal, sphenoidal and sellar phases of the trans-sphenoidal approach. Detailed knowledge of the basic anatomical relationships through the view of the endoscope and performing endoscopic dissections in large number of specimens will facilitate the endoscopic surgical procedures and decrease the rate of surgical complications.

Management of Cushing's disease using cavernous sinus sampling: effectiveness in tumor lateralization.

OBJECTIVE: The aim of this study was to determine the accuracy of bilateral cavernous sinus sampling (CSS) in preoperative tumor lateralization (right/left) within the pituitary in patients with Cushing's disease (CD). PATIENTS AND METHODS: The study consisted of 26 consecutive patients who had undergone CSS followed by transsphenoidal surgery (TS) for CD between 2000 and 2006 at our institution. The magnetic resonance imaging (MRI) of the selected patients either revealed a normal pituitary or a lesion

Acute traumatic orbital encephalocele related to orbital roof fracture: reconstruction by using porous polyethylene.

A case report of acute traumatic orbital encephalocele related to orbital roof fracture and its management were presented. Acute traumatic encephalocele related to orbital roof fracture is unusual. Early diagnosis and treatment are very important since the raised intraorbital pressure may irreversibly damage the optic nerve. Orbital computerized tomography with thin axial and coronal sections should be performed in an acute traumatized patient with a concurrent orbital trauma. Reconstruction of the orbital roof is the key step of the surgical treatment and should be performed in every case. Porous polyethylene (Medpor) has been used for many years in reconstructive surgeries and it is superior to other allografts in many ways. In our case, the orbital roof reconstruction was done by Medpor and the early and late cosmetic results were excellent. The important features of acute traumatic encephalocele secondary to orbital roof fractures in terms of presentation, diagnosis and surgical steps were also stressed.

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.

An Exceptional Neurosurgical Presentation of a Patient with Osteopetrosis.

BACKGROUND: Osteopetrosis (OP) is a varied clinical condition caused by malfunction or insufficient development of osteoclasts, or both. Neurologic findings can occur because of osteopetrotic conditions restricting neural foramina through which the spinal cord, cranial nerves, or major vascular structures traverse the skull. Renal tubular acidosis (RTA) is a well-documented condition with OP. However, Chiari I malformation is rarely reported concomitantly with OP. CASE DESCRIPTION: We present a patient with a known RTA who was admitted with a rapid progressive tetraparesis within 24 hours. Clinical and radiologic evaluation of the patient revealed OP with RTA together with Chiari I malformation and holocord hydromyelia. Management of the patient was started with correction of severe hypokalemia (K: 1.4 mEq/L), which resulted in dramatic improvement in tetraparesis. Two days later, a posterior fossa bone decompression with ventriculoperitoneal shunt placement during the same session led to prominent decrease in size of the ventricles and the hydromyelia on long-term follow-up. CONCLUSIONS: Patients with OP can exhibit many clinical conditions. However, our case involved an unusual and rapid progressive tetraparesis, which could confuse the management as necessitating an emergent posterior fossa decompression. Stabilizing the metabolic status of the patient facilitated elective surgery, which further improved patient's neurologic findings and diminished hydromyelia on long-term follow-up.