Anatomic variations of the human falx cerebelli and its association with occipital venous sinuses.

PURPOSE: Human falx cerebelli is an important anatomical structure in regard to its relations with venous structures during infratentorial approach to reach cerebellar tumors, vascular malformations, traumatic hemorrhage and Chiari malformations. The present study aim to describe the different types of variations of the falx cerebelli, its morphological features and its association with occipital venous sinuses. METHOD: In this study 49 dura mater was obtained from the Institution of Forensic Medicine. The length, width and the depth of the falx cerebelli were measured using a digital compass. The data obtained were statistically analyzed in relation to age and gender. The relations of the falx cerebelli with the occipital sinus was documented. Histological sections from the falx cerebelli were stained with Hematoxylin Eosin to evaluate the fine structure. RESULTS: Among the 49 falx cerebelli examined 36 (73.5%) were classified as normal. The average length, width and depth of the normal falx cerebelli was 3.7, 1.0 and 0.4 cm respectively. Of the 49 falx cerebelli in 1 (2%) case it was absent, in 5 cases (10.2%) duplicate, in 5 cases (10.2%) triplicate, in 1 (2%) case quadruplets and in 1 case (2%) it was five-folded. The proximal and the distal attachments of the falx cerebelli showed 3 types of variations; both attachments triangular, the proximal attachments triangular and the distal ramified and distal attachments triangular and the proximal attachments ramified. The drainage of the occipital sinus of falx cerebelli with variations were evaluated. The increased number of falx cerebelli highly corresponded with the increased number of occipital sinus. CONCLUSIONS: The dural-venous variation in the posterior cranial fossa can be problematic in various diagnostic and operative procedures of this region. Neurosurgeons should be aware of such variations, as these could be potential sources of haemorrhage during the midline suboccipital and infratentorial approaches.

Peripheral Facial Nerve Palsy After Ventriculoperitoneal Shunt Surgery: An Anatomical Perspective.

In this report, we present a case of peripheral facial nerve palsy (FNP) due to injury of the facial nerve trunk that occurred during tunneling of a VP shunt catheter. We aimed to present the preventive measures by taking the anatomical causes of this complication. A 75-year old was stated a VP shunt surgery for treatment of Normal Pressure Hydrocephalus (NPH). His physical examination of skull was revealed ecchymosis behind the right ear. The neurological examination revealed a peripheral FNP (Grade IV, House? Brackmann Facial Nerve Grading System) with no alteration in lacrimation and taste sensation. A computed tomography (CT) detected edema of the extratemporal segment of right facial nerve. Surgeons performing ventriculoperitoneal shunt surgery should have comprehensive knowledge of the anatomical course of facial nerve. In this way, they can beware to proper placement of the shunt catheter during the tunnelling procedure to prevent complications.

Evidence that osteogenic and neurogenic differentiation capability of epidural adipose tissue-derived stem cells was more pronounced than in subcutaneous cells

Background/aim: The management of dura-related complications, such as the repairment of dural tears and reconstruction of large dural defects, remain the most challenging subjects of neurosurgery. Numerous surgical techniques and synthetic or autologous adjuvant materials have emerged as an adjunct to primary dural closure, which may result in further complications or side effects. Therefore, the subcutaneous autologous free adipose tissue graft has been recommended for the protection of the central nervous system and repairment of the meninges. In addition, human adipose tissue is also a source of multipotent stem cells. However, epidural adipose tissue seems more promising than subcutaneous because of the close location and intercellular communication with the spinal cord. Herein, it was aimed to define differentiation capability of both subcutaneous and epidural adipose tissue-derived stem cells (ASCs). Materials and methods: Human subcutaneous and epidural adipose tissue specimens were harvested from the primary incisional site and the lumbar epidural space during lumbar spinal surgery, and ASCs were isolated. Results: The results indicated that both types of ASCs expressed the cell surface markers, which are commonly expressed stem cells; however, epidural ASCs showed lower expression of CD90 than the subcutaneous ASCs. Moreover, it was demonstrated that the osteogenic and neurogenic differentiation capability of epidural adipose tissue-derived ASCs was more pronounced than that of the subcutaneous ASCs. Conclusion: Consequently, the impact of characterization of epidural ASCs will allow for a new understanding for dural as well as central nervous system healing and recovery after an injury.

Diagnostic Importance of Axial Loaded Magnetic Resonance Imaging in Patients with Suspected Lumbar Spinal Canal Stenosis.

OBJECTIVE AND BACKGROUND: To study the efficacy of lumbar (AL) magnetic resonance imaging (MRI) in patients with suspected lumbar spinal stenosis (LSS), with and without AL compression. Supine MRI is used in the assessment of patients with LSS. However, MRI findings may poorly correlate with neurologic findings because of the morphologic changes of the lumbar spinal canal between upright standing and supine positions. In patients without significant stenosis in routine lumbar MRI, by applying AL, MRI can show significant LSS. METHODS: This study included 103 consecutive patients (188 disc levels) who presented with neurogenic claudication with and without low back pain. AL was performed using a nonmagnetic compression device for 5 minutes. T1- and T2-weighted axial and sagittal sequences were obtained during AL applied to the spine. The dural sac cross-sectional area (DSCA) appeared to be narrow at each disc level of L4-5 to L5-S1 in all patients and was measured using T2-weighted images in routine supine and AL images. RESULTS: The groups included patients with a reduction in the DSCA (>15 mm2) according to patient age and DSCA in routine spine MRI. The mean DSCA of the disc levels without and with AL were 138 mm2 and 123 mm2, with a mean difference of 15 mm2 at L4-5, 134 mm2 and 125 mm2 and a mean difference of 9 mm2 at L5-S1, respectively. CONCLUSIONS: The use of AL MRI in patients with clinically suspected LSS could reduce the risk of misdiagnosis of stenosis, leading to inappropriate treatment.

Assessment of the corticospinal fiber integrity in mirror movement disorder.

Mirror movements are unintended movements occurring on one side of the body that mirror the contralateral voluntary ones. It has been proposed that mirror movements occur due to abnormal decussation of the corticospinal pathways. Using detailed multidisciplinary approach, we aimed to enlighten the detailed mechanism underlying the mirror movements in a case subject who is diagnosed with mirror movements of the hands and we compared the findings with the unaffected control subjects. To evaluate the characteristics of mirror movements, we used several techniques including whole exome sequencing, computed tomography, diffusion tensor imaging and transcranial magnetic stimulation. Computed tomography showed the absence of a spinous process of C5, fusion of the body of C5-C6 vertebrae, hypoplastic dens and platybasia of the posterior cranial fossa. A syrinx cavity was present between levels C3-C4 of the spinal cord. Diffusion tensor imaging of the corticospinal fibers showed disorganization and minimal decussations at the lower medulla oblongata. Transcranial magnetic stimulation showed that motor commands were distributed to the motor neuron pools on the left and right sides of the spinal cord via fast-conducting corticospinal tract fibers. Moreover, a heterozygous missense variation in the deleted in colorectal carcinoma gene has been observed. Developmental absence of the axonal guidance molecules or their receptors may result in abnormalities in the leading of the corticospinal fibers. Clinical evaluations and basic neuroscience techniques, in this case, provide information for this rare disease and contribute to our understanding of the normal physiology of bimanual coordination.

A thoracic vertebral brown tumor presenting with paraparesis in a patient with end-stage renal disease.

Vertebral brown tumors are rare, non-neoplastic bone lesions that occur in the setting of hyperparathyroidism. There are differences in the management of them in the literature. Because brown tumors usually resolve after a parathyroidectomy. We present a case of a thoracic vertebral brown tumor with paraparesis.

The contributions to the human dorsal column tracts from the spinal cord laminae.

The dorsal column tracts (fasciculus gracilis and fasciculus cuneatus) are concerned with discriminative qualities of sensation. There are controversial descriptions related to the relations of dorsal column tracts with the dorsal horn laminae in text-books. The present study aims to define the laminae of the dorsal horn of the spinal cord that contribute fibers to the dorsal column tracts in the cervical, thoracic and lumbar spinal level. Series paraffin spinal cords sections of six formalin-embalmed adult human cadavers were evaluated. The present study shows that dorsal column tracts receive fiber contributions from laminae III and V and from Clarke's dorsal nucleus at varying spinal levels. At upper cervical levels (C1-C4) fiber contributions were from lamina V and few from lamina III, and at lower cervical levels (C5-C8) there were, in addition to these laminae, also contributions from the Clarke's dorsal nucleus. At upper thoracic levels (T1-T4) fiber contributions were from lamina V and few from Clarke's dorsal nucleus. At lower thoracic (T5-T12) and lumbar levels (L1-L5), in contrast, fiber contributions were only from Clarke's dorsal nucleus. The detailed knowledge of organization of the dorsal column tracts of the spinal cord may pave the way for future treatments of the spinal cord injuries.

The Supraorbital Keyhole Approach.

AIM: The major aim of the present anatomical study was to demonstrate the anatomical structures that can be visualized using the supraorbital keyhole approach, both endoscopically and microscopically, from an eyebrow incision to intracranial structures. Furthermore, it defines an optimal craniotomy for surgery. METHODS: Fine dissection was performed on each side of 5 formalin-fixed adult cadavers according to the surgical procedures of the supraorbital keyhole approach, and each step was documented both endoscopically and microscopically. Furthermore, the distance between the superior temporal line and the supraorbital notch/foramen was measured from the 10 total sides of the 5 cadavers and from the 118 sides of the 59 autopsies. RESULTS: Tumors and aneurysms of the anterior cranial fossa can be visualized during the supraorbital keyhole approach. The average distance between the superior temporal line and the supraorbital notch/foramen was measured. The distance obtained from the autopsies on the 25 females was 31.56 ±â€Š4.03  mm on the right side and 31.04 ±â€Š5.40  mm on the left side. The average distance obtained from the autopsies on the 34 males was 34.00 ±â€Š4.59  mm on the right side and 33.59 ±â€Š5.41  mm on the left side. There was no statistically significant difference between right and left in the female and male autopsies or between sexes. CONCLUSIONS: This anatomical study showed that structures in the anterior and middle cranial fossa can be reached via the supraorbital keyhole craniotomy approach with minimal brain retraction and adequate exposure and with minimal craniotomy size.

Intradural communication between dorsal rootlets of spinal nerves: their clinical significance.

BACKGROUND: Anatomical and surgical textbooks give almost no attention to the intradural communications between dorsal rootlets of adjacent spinal nerves. These communications can be of significance in various neurosurgical procedures and clinical conditions of the region. METHODS: The spinal cord of six formaldehyde-fixed cadavers was dissected from C1-S5. The dorsal rootlets of the spinal nerves were exposed via a posterior approach and communications between adjacent spinal nerves were documented. RESULTS: The frequency of communication between adjacent dorsal rootlets of the spinal nerves showed variations among spinal levels. Thirty-eight dorsal rootlet communications were observed in six cadavers (12 sides) and 20 (52.6%) were at cervical levels, 14 (36.8%) at thoracic levels, and four (10.5%) at lumbar levels. The majority of communications were observed on the left side (65.8%). Communications were most frequently observed at cervical (C4-C5, C5-C6) and upper thoracic (T1-T2) levels and seen least frequently at lower thoracic and lumbar levels. No communications were observed at sacral levels. Five types of communication were observed: I. oblique ascending, II. oblique descending III. short Y, IV. long Y and V shaped. None of the communication extended beyond one segment at any spinal level. The occurrence of such dorsal rootlet communications ranged from 3 to 7 for each cadaver and the mean was 4.8 ± 1.3. Histological sections from various levels of the dorsal rootlet communications showed that all consisted of myelinated fibers of varying diameters. CONCLUSIONS: Such communications may lead to misinterpretation of the pathology on the basis of clinical signs and symptoms and also should be considered in rhizotomy.

A sine-wave-shaped skin incision for inserting deep-brain stimulators.

BACKGROUND: The sine-wave-shaped skin incision is a technique that minimizes skin-related complications near burr hole caps after electrode placement for deep-brain stimulation (DBS). METHODS: Between 2011 and 2013, 54 DBS electrodes were implanted in 27 consecutive patients with Parkinson's disease (PD), essential tremor, or dystonia. The sine-wave incision was used in 26 patients and conventional bilateral linear scalp incisions were used in one patient. RESULTS: None of the patients whose operations involved sine-wave-shaped incisions developed hardware-linked complications such as skin infection or skin erosion. The one patient who underwent conventional bilateral linear scalp incisions developed a skin infection. CONCLUSION: By preserving the vascular anatomy of the scalp and reducing skin tension at the wound site, the sine-wave-shaped incision promotes wound healing.

An unusual location for a choroid plexus papilloma: the pineal region.

PURPOSE: Choroid plexus papillomas (CPP) are rare benign neoplasms of the central nervous system that occur most often in children during the first decade of life. They occur most often in the lateral ventricle. It is extremely rare for a CPP to occur in the pineal region. We describe the case of a child with a CPP located in the pineal region, who was initially diagnosed with obstructive hydrocephalus by cranial computed tomography (CT). METHODS: A 9-year-old female patient presented with complaints of visual disturbance, nausea, and vomiting. Magnetic resonance imaging (MRI) showed a poor contrast-enhanced pineal-localized lesion. Anatomical variations within the patient caused her surgery to proceed using a supratentorial-occipital interhemispheric approach. RESULTS: The tumor was totally removed, and a histological examination revealed the tumor to be a typical CPP. The patient received follow-up neurological and ophthalmologic examinations at 3, 6, 9, 12, 24, and 36 months postoperatively, which demonstrated her progressive improvement. CONCLUSIONS: CPPs may have a wide range of locations and resulting symptoms. However, the pineal region is a rarely encountered location, particularly for pediatric patients. It is of great value to correctly differentiate neoplasms such as germ cell tumors, pineocytomas, meningiomas, and astrocytomas, so that patients receive the correct diagnosis and treatment approach.

Skipping posterior dynamic transpedicular stabilization for distant segment degenerative disease.

Objective. To date, there is still no consensus on the treatment of spinal degenerative disease. Current surgical techniques to manage painful spinal disorders are imperfect. In this paper, we aimed to evaluate the prospective results of posterior transpedicular dynamic stabilization, a novel surgical approach that skips the segments that do not produce pain. This technique has been proven biomechanically and radiologically in spinal degenerative diseases. Methods. A prospective study of 18 patients averaging 54.94 years of age with distant spinal segment degenerative disease. Indications consisted of degenerative disc disease (57%), herniated nucleus pulposus (50%), spinal stenosis (14.28%), degenerative spondylolisthesis (14.28%), and foraminal stenosis (7.1%). The Oswestry Low-Back Pain Disability Questionnaire and visual analog scale (VAS) for pain were recorded preoperatively and at the third and twelfth postoperative months. Results. Both the Oswestry and VAS scores showed significant improvement postoperatively (P < 0.05). We observed complications in one patient who had spinal epidural hematoma. Conclusion. We recommend skipping posterior transpedicular dynamic stabilization for surgical treatment of distant segment spinal degenerative disease.

Clinical analysis of 21 cases of spinal cord ependymoma : positive clinical results of gross total resection.

OBJECTIVE: To evaluate the clinical results of gross total resection in the surgical approach to spinal ependymoma. METHODS: Between June 1995 and May 2009, 13 males and 8 females (mean age 34) diagnosed with intramedullary or extramedullary spinal ependymoma were surgically treated at our centre. The neurological and functional state of each patient were evaluated according to the modified McCormick scale. RESULTS: The average follow-up duration was 54 months (ranging from 12 to 168 months). The locations of the lesions were: thoracic region (4, 19%), lumbar region (7, 34%), cervical region (4, 19%), cervicothoracic region (3, 14%) and conus medullaris (3, 14%). Four patients (19%) had deterioration of neurological function in the early postoperative period. The neurological function of three patients was completely recovered at the 6th postoperative month, while that of another patient was recovered at the 14th month. In the last assessment of neurological function, 20 patients (95%) were assessed as McCormick grade 1. No perioperative complications developed in any of our patients. In one patient's 24-month assessment, tumour recurrence was observed. Re-operation was not performed and the patient was taken under observation. CONCLUSION: Two determinants of good clinical results after spinal ependymoma surgery are a gross total resection of the tumour and a good neurological condition before the operation. Although neurological deficits in the early postoperative period can develop as a result of gross total tumour resection, significant improvement is observed six months after the operation.