The historical evolution of the fornix and its terminology: a review.

The historical evolution of the fornix has not been sufficiently reviewed in the literature. In this article, we follow this evolution from the first mention of the fornix in animal dissections of the second century AD, to the legalization of cadaver dissection in the 1300 s, to the introduction of neural staining techniques and the microscope in the seventeenth century, to today. We summarize the focus of fornix studies on memory to reveal its relationship with the hippocampus. We then cover the detection of the fornix and its neural connections noninvasively with the advancement of radiological imaging techniques. Finally, we discuss the prominence of the fornix as a target for deep brain stimulation in Alzheimer's disease and post-traumatic brain injury memory disorders.

Microsurgical anatomy and insular connectivity of the cerebral opercula.

OBJECTIVE: Radiological, anatomical, and electrophysiological studies have shown the insula and cerebral opercula to have extremely high functionality. Because of this complexity, interventions in this region cause higher morbidity compared to those in other areas of the brain. In most early studies of the insula and white matter pathways, insular dissection was begun after the opercula were removed. In this study, the authors examined the insula and deep white matter pathways to evaluate the insula as a whole with the surrounding opercula. METHODS: Twenty formalin-fixed adult cerebral hemispheres were studied using fiber microdissection techniques and examination of sectional anatomy. Dissections were performed from lateral to medial, medial to lateral, inferior to superior, and superior to inferior. A silicone brain model was used to show the normal gyral anatomy. Sections and fibers found at every stage of dissection were photographed with a professional camera. MRI tractography studies were used to aid understanding of the dissections. RESULTS: The relationships between the insula and cerebral opercula were investigated in detail through multiple dissections and sections. The relationship of the extreme and external capsules with the surrounding opercula and the fronto-occipital fasciculus with the fronto-orbital operculum was demonstrated. These findings were correlated with the tractography studies. Fibers of the extreme capsule connect the medial aspect of the opercula with the insula through the peri-insular sulcus. Medial to lateral dissections were followed with the removal of the central core structures, and in the last step, the medial surface of the cerebral opercula was evaluated in detail. CONCLUSIONS: This anatomical study clarifies our understanding of the insula and cerebral opercula, which have complex anatomical and functional networks. This study also brings a new perspective to the connection of the insula and cerebral opercula via the extreme and external capsules.

Complications of pediatric auditory brain stem implantation via retrosigmoid approach.

OBJECTIVE: We aimed to present the complications of auditory brain stem implantations (ABI) in pediatric patients which were performed via retrosigmoid approach. METHODS: Between March 2007 and February 2010, five prelingually deaf children underwent ABI (Medel device) operation via retrosigmoid approach. All children had severe cochlear malformations. The ages ranged from 20 months to 5 years. The perioperative complications encountered in 2 patients were evaluated retrospectively. RESULTS: No intraoperative complication was observed in the patients. Cerebrospinal fluid (CSF) leakage was the most common postoperative complication that was seen in 2 patients. The CSF leak triggered a cascade of comorbidities, and elongated the hospitalization. CONCLUSION: Pediatric ABI surgery can lead to morbidity. The CSF leak is the most common complication encountered in retrosigmoid approach. The other complications usually result from long-term hospital stay during treatment period of the CSF leak. Therefore, every attempt must be made to prevent occurrence of CSF leaks in pediatric ABI operations.

Evaluation of the Medicolegal Process in Neurosurgical Practice with A Scenario.

The main purpose of medicine is to protect humans from diseases and its complications. Patients may be at risk in the course of diseases or during medical and surgical treatments, which can have undesirable consequences, including death. These risks, which are accepted by all medical authorities and medical literature, are called "complications." One of the responsibilities of the physicians is to detect complications on time and to manage them in accordance with the current medical standards. In the last two decades, allegations that any medical practice is "faulty" have been increasing, and these allegations are presented to the press and media regardless of whether they are justified. This situation adversely affects the medical practice, leading to defensive medical practices, affecting the public health. In this article, we presented our medical responsibilities over a neurosurgical scenario and mentioned the legal procedures to be experienced in such a situation. As physicians, we must know all the legal responsibilities of our profession and record all stages of treatments applied, to suffer the least damage from these claims and legal processes that cause pecuniary and non-pecuniary injury.

Anti-apoptotic and neuroprotective effects of α-lipoic acid on spinal cord ischemia-reperfusion injury in rabbits.

PURPOSE: Radical oxygen species produced after injury counteracts antioxidant activity and frequently causes severe oxidative stress for the tissues. Alpha-lipoic acid is a powerful metabolic antioxidant with immunomodulatory effects which provides neuroprotection. The aim of this study is to investigate the neuroprotective and anti-apoptotic effects of alpha-lipoic acid on spinal cord ischemia-reperfusion. METHODS: Twenty-four adult, male, New Zealand rabbits were divided into sham (n = 8), control (n = 8), and treatment groups (n = 8). The abdominal aorta was clamped for 30 min by an aneurysm clip, approximately 1 cm below the renal artery and 1 cm above the iliac bifurcation in control and treatment groups. Only laparotomy was performed in the sham group. Twenty-five cubic centimeters of saline in control group and 100 mg/kg lipoic acid were administered intraperitoneally in the treatment group after closure of the incision. The animals were killed 48 h later. Spinal cord segments between L2 and S1 were harvested for analysis. Levels of nitric oxide, glutathione, malondialdehyde, advanced oxidation protein products, and superoxide dismutase were analyzed as markers of oxidative stress and inflammation. Caspase-3 activity was analyzed to detect the effect of lipoic acid on apoptosis. RESULTS: In all measured parameters of oxidative stress, administration of lipoic acid significantly demonstrated favorable effects. Both plasma and tissue levels of nitric oxide, glutathione, malondialdehyde, and advanced oxidation protein products significantly changed in favor of antioxidant activity. There was no significant difference between the plasma superoxide dismutase levels of the groups. Histopathological evaluation of the tissues also demonstrated significant decrease in cellular degeneration and infiltration parameters after lipoic acid administration. However, lipoic acid has no effect on caspase-3 activity. CONCLUSIONS: Although further studies considering different dose regimens and time intervals are required, the results of the present study prove that alpha-lipoic acid has favorable effects on experimental spinal cord ischemia-reperfusion injury.

The role of fibroblast growth factor-2 in healing the dura mater after inducing cerebrospinal fluid leakage in rats.

We conducted a study to determine the effectiveness of topically applied recombinant mouse fibroblast growth factor-2 (FGF-2) in healing the dura mater in a rat with dura mater injury and cerebrospinal fluid leakage. Laminectomies were performed in 32 rats at the level of the L2-L4 vertebrae, and a dura mater defect was created. Sixteen rats were treated postoperatively with locally applied recombinant mouse FGF-2, and 16 animals received normal saline. FGF-2 effects on dura mater healing, cerebrospinal fluid leakage, and wound healing were assessed at 3 and 6 weeks postoperatively. The extent of dura mater healing was evaluated by histological analysis. We found that dura mater healing was significantly increased (p<0.05) in rats treated with FGF-2 compared with rats in the control group. In this experimental model, locally applied FGF-2 effectively increased dura mater healing and induced no side effects.

A comparison of the effectiveness of waxed paper and Gore-Tex on the minimally invasive epidural fibrosis model.

STUDY DESIGN: Experimental animal study. OBJECTIVE: The authors conducted a study to determine the effectiveness of waxed paper in preventing postlaminectomy epidural fibrosis in rats. SUMMARY OF BACKGROUND DATA: Extensive epidural fibrosis after lumbar surgery may be the underlying cause in most cases of failed back surgery syndrome. Various materials have been used to prevent epidural fibrosis, but only moderate success has been shown. METHODS: Laminectomies were performed at the fourth lumbar vertebra (L-4) in 30 rats. Waxed paper or Gore-Tex was applied in a blinded fashion to the operative sites. In the control group, only the L-4 laminectomy was performed. The rats were killed 28 days after surgery. RESULTS: The extent of epidural fibrosis was evaluated by histologic analysis. There was a meaningful statistical difference among the waxed paper group and the Gore-Tex group compared with the control group, but there was no difference when the effectiveness of waxed paper was compared with that of Gore-Tex. CONCLUSIONS: In this experimental model, the waxed paper applied locally effectively reduced epidural fibrosis, completely avoided dural adherence, and induced no side effects.

The role of FloSeal in reducing epidural fibrosis in a rat laminectomy model.

BACKGROUND AND PURPOSE: An increased amount of fibrosis formed after lumbar surgery may be the underlying cause of the failed back surgery syndrome in most cases. Various materials have been used to prevent epidural fibrosis, but only limited success has been achieved. In this study, the authors investigated the effect of FloSeal (a gelatine-containing thrombin-based haemostatic agent) on spinal epidural fibrosis in a rat laminectomy model. MATERIAL AND METHODS: Sixteen Wistar rats underwent laminectomy at L4 and L5 levels. In 8 rats, 0.5 mL of FloSeal was locally applied to the laminectomy site. The laminectomy site was irrigated with saline in the control group of 8 other rats. The rats were sacrificed four weeks later. Each specimen was examined for density of fibrosis, and both fibroblast and inflammatory cell density. RESULTS: Epidural fibrosis density differed significantly between the FloSeal group and the control group. Evaluation of the fibroblast density and the inflammatory cell density showed a statistically significant difference between the FloSeal group and the control group. CONCLUSION: Application of FloSeal at a laminectomy site may be useful to decrease adhesion at the interface between the dura mater and epidural fibrosis.

Effect of a chloride channel inhibitor, 5-nitro-2- (3-phenylpropylamino)-benzoate, on endothelin-1 induced vasoconstriction in rabbit basilar artery.

AIM: Endothelin-1 (ET-1) has been implicated in the pathophysiology of cerebral vasospasm. Chloride (Cl-) channels exist in vascular smooth muscle and activation of these channels leads to depolarization and contraction. The aim of the present study was to test the effect of 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB), a Cl- channel antagonist, on the ET-1-induced cerebral vasospasm in rabbit basilar artery and thus investigate the contribution of Cl- channels. MATERIAL AND METHODS: Thirty rabbits were divided into five groups and received intra-arterial injection of isotonic saline (Group I, n=6), ET-1 (group II, n=6), ET-1 plus NPPB (Group III, n=6), dimethylsulfate (DMSO4) (Group IV, n = 6) and NPPB (Group V, n=6). Pre and post injection basilar artery diameters were measured in each group and transmission electron microscopic investigations on basilar arteries were performed. RESULTS: The mean pre-injection and post-injection vessel diameters were 0.8833 mm and 0.7000 mm in ET-1 group, 0.6833 mm and 0.8500 mm in ET-1 + NPPB group. NPPB administered prior to ET-1 injection, prevented the ET-1-induced vasoconstriction. Additionally, NPPB prevents the ET-1 induced changes in vessel wall and neurons in the brain stem. CONCLUSION: The results of this study add further insights to our armamentarium against cerebral vasospasm.

A comparison of the local effectiveness of mitomycin C, aprotinin, and Adcon-L in experimental peridural fibrosis.

BACKGROUND: Peridural fibrosis and leptomeningeal adhesion formation are among the common causes of FBSS. Various materials have been used to prevent the compressive effect of postoperative PF on neural structures. We investigated and compared the effects of 3 agents--aprotinin, mitomycin C, and Adcon-L--to PF after lumbar laminectomy in rabbits. METHODS: Four groups each including 8 rabbits were formed: Adcon-L, aprotinin, mitomycin C, and control groups. L3 laminectomy was performed on each animal. One of the 3 agents was administered locally to laminectomy areas in each group. All the animals were killed 4 weeks after the surgery. Peridural fibrosis, arachnoidal fibrosis, and dural adhesions were evaluated histologically and graded. The results were compared statistically by using a standard chi2 test. RESULTS: There were significant differences in the PF grades among the experimental groups and the control group (P < .05). When the fibroblast density and the inflammatory cell density were evaluated, the grades of the experimental groups were better compared with the grades of the control group, but the difference was not statistically significant (P > .05). CONCLUSION: Various materials have been used to prevent the compressive effect of postoperative PF on the neural structures. Aprotinin, mitomycin C, and Adcon-L are effective in preventing PF and dural adhesions in postlaminectomy areas. However, mitomycin C and Adcon-L were more effective than aprotinin in preventing peridural scarring.

Should we operate all extradural spinal arachnoid cysts? Report of a case.

Spinal canal extradural arachnoid cyst is an uncommon, expanding lesion which may communicate with the subarachnoid space. They may be either intra or extradural with intradural cysts being less common. Spinal arachnoid cysts are usually in the thoracic spine, and they may cause symptoms due to spinal cord compression. Although surgery is the preferred way of management, there are reported cases with long term follow-up in the literature. Here we present a 14-year-old female who presented with intermittent low back pain for 1 year and a spinal arachnoid cyst that was followed for two years without any neurological deterioration.

The effects of topical granulocyte-macrophage colony-stimulating factor on dural healing in rats after induced cerebrospinal fluid leakage.

OBJECT: Dural defects must be repaired to protect the central nervous system from contamination. Although there are various experimental and commercial substances available for this purpose, the ultimate method of watertight dural closure has yet to be discovered. In this study, the authors investigate the effects of topically applied recombinant mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) on dural healing in a rat model of dural injury and cerebrospinal fluid leakage. METHODS: In this experimental model, a dural defect at the level of the L1-2 vertebrae was created in 32 Wistar rats. Sixteen animals were treated with locally applied recombinant mouse GM-CSF postoperatively, and 16 animals received normal saline. The effects of GM-CSF on dural healing, cerebrospinal fluid leakage, and wound healing were assessed 2 and 4 weeks postoperatively. Dural healing was evaluated histologically. RESULTS: Dural healing was increased in rats treated with GM-CSF compared with rats in the control group. This difference was statistically significant (p < 0.05). CONCLUSIONS: Cerebrospinal fluid leakage may impede healing of dural defects. Topically applied GM-CSF seems to aid in dural healing.

Ischemic stroke complicated by a brain abscess: a case report and review of the literature.

Ischemic stroke and brain abscess are life threatening, severe medical conditions requiring urgent and comprehensive evaluation. Brain abscess is a very rare and dangerous complication of ischemic stroke that can be treated successfully when diagnosed. Association of these two life threatening condition may cause catastrophic results. In this report, we present our experience with an ischemic stroke case complicated by a brain abscess under the light of previous literature. A 64-year-old patient with a cerebral infarction complicated by a cerebral abscess is reported with its clinical and radiological features. Because of their insidious and opportunistic nature, brain abscess complicating cerebral infarcts are pathologies requiring a high index of suspicion for proper treatment and favorable results.

Frontal sinus osteoma associated with pneumocephalus.

The most common causes of intracranial air are head trauma and neurosurgical procedures. Less common etiologies include infection due to gas-forming organisms, mucoceles, tumours, congenital neuroenteric cysts, and dural defects. Here, we present a case of a frontal sinus osteoma associated with longstanding pneumocephalus.

Dorsolumbar junction spinal tuberculosis in an infant: case report.

The treatment of spinal tuberculosis is a challenging and controversial problem. The authors present the rare case of an 8-month-old infant with dorsolumbar junction tuberculosis. The child did not sit or stand and a hump was noted on his back. Radiological evaluations demonstrated destruction by a tuberculous abscess of the T-12 and L-1 vertebral bodies, extending into the psoas muscles and spinal canal. In addition to medical therapy, radical debridement and grafting were performed via an anterolateral approach. The follow-up period was 2 years. The difficulties in the management of spinal tuberculosis in infants are discussed.

Anterior thoracic myelomeningocele presenting as a retromediastinal mass. Case report.

Myelomeningocele presenting as a retromediastinal mass originating from the midline defect through the fused T-4, T-5, and T-6 VBs is described. An 11-year-old boy with a completely normal systemic and neurological examination suffering pulmonary problems such as effort dyspnea and severe kyphosis was evaluated and an anterior thoracic myelomeningocele was diagnosed. The boy underwent surgery for excision of the meningomyelocele sac and correction of kyphoscoliosis. His year-long follow-up period as an outpatient was uneventful. A comprehensive PubMed search of the literature returned no results for an "anterior thoracic myelomeningocele" query. To the best of the authors' knowledge, this is the only case described in the literature.

Simple bone cyst in spinous process of the c4 vertebra.

Simple bone cysts are common, benign, fluid-filled, cystic lesions that occur mostly in the metaphysis of the long bones and are rarely found in vertebrae. A case of a simple bone cyst in the spinous process of the fourth cervical vertebra in a 26-year-old woman is reported. According to the radiologic findings, the lesion was identified as a simple bone cyst, and the diagnosis was verified by surgical and histopathologic examinations.

Topical mitomycin C-induced inhibition of postlaminectomy peridural fibrosis in rabbits.

OBJECT: The authors conducted a study to determine the effectiveness of mitomycin C in preventing postlaminectomy peridural fibrosis in rabbits. METHODS: Laminectomies were performed at L-4 in 12 rabbits. Color-coded cotton pads soaked either with 0.02% mitomycin C or saline were applied in a blinded fashion to the operative sites, with saline-treated laminectomy sites serving as controls. The rabbits were killed 30 days after surgery. The extent of peridural fibrosis was evaluated by histological analysis. The mitomycin C-treated sites showed significantly decreased peridural fibrosis. CONCLUSIONS: Peridural fibrosis can be a devastating condition that develops after laminectomy. Topical application of mitomycin C may be a successful method of preventing postlaminectomy peridural fibrosis.

Terminal syringomyelia: is it as innocent as it seems?--Case report.

A 5-day-old newborn girl presented with cutaneous signs of hypertrichosis, skin dimple, and subcutaneous lipoma in the lumbar region. Magnetic resonance (MR) imaging of the thoracolumbar spine demonstrated spinal dermal sinus, type II split cord malformation, and tethered cord. A small terminal syringeal cavity was also present. Five months after the diagnosis, weakness in dorsal flexion of the bilateral feet and toes was detected. Surgery to untether the cord was performed. Her deficits resolved completely. Nearly 4 years later, she was admitted with weakness in dorsal flexion of the right foot and toe. MR imaging of the spine showed holocord syringomyelia, postoperative changes, and tethered cord. No Chiari malformation was seen. Syringosubarachnoid shunt placement was performed. Terminal syringomyelia is common in cases of occult spinal dysraphism, but the natural history and management remain unclear. Progression, regression, or persistence of terminal syringeal cavity can occur whether untethering is performed or not. Progression of the terminal syrinx occurred after tethered cord release and the enlargement of the cavity involved the entire spinal cord in the present case. Terminal syringomyelia requires close follow up for a long time even in asymptomatic cases. Surgical treatment should be considered in symptomatic cases.