Angiographic Angular Adjustment: Matching Angiographic Views and Surgical Findings to Estimate the Actual Arterial Anatomy in Surgery for Intracranial Aneurysm - Technical Note.

AIM: To describe a simple technique of angular adjustment of cerebral angiographic views that makes them similar to the surgical field under the operation microscope. MATERIAL AND METHODS: The technique of angular adjustment consists of three steps: 1. Upside-down 180-degree rotation of the standard angiographic anterior-posterior view, 2. Adjustment of the course of the angiographic internal carotid artery according to the actual internal carotid artery seen in surgery under the operating microscope, and 3. A final and more accurate angular adjustment by rotating the angiographic view in its final position, as soon as parent arteries to aneurysm, such as the internal carotid, anterior cerebral, and middle cerebral arteries, are seen in surgery. RESULTS: The use of the technique provided a fair approximation of a rotated angiographic view and the actual surgical point of view. The technique is simple, and no sophisticated technology is needed. CONCLUSION: The angiographic data adjusted angularly to the surgeon?s point of view at surgery, very similar to the actual directions of arteries and the fundus of the aneurysm, is likely helpful to the microneurosurgeon for safely exploring aneurysms in conjunction with proximal and distal arteries.

Comparison of the Morphologic and Mechanical Features of Human Cranial Dura and Other Graft Materials Used for Duraplasty.

OBJECTIVE: This study aimed to compare the thickness and mechanical properties of the frontal; parietal; temporal; occipital human dura; autogenous grafts (facia lata, temporal fascia, galea aponeurotica); and artificial dura. METHODS: Sagittal and transverse dura samples were obtained from standard regions of the cranial dura from 30 autopsies for histologic and mechanical property measurements. Identical measurements were made for the autogenous grafts artificial dura, and the results were statistically analyzed. RESULTS: The thickness of the temporal (0.35 ± 0.11 mm), parietal (0.44 ± 0.13 mm), frontal (0.38 ± 0.12 mm), and occipital (0.46 ± 0.18 mm) dura showed regional variations. The parietal and occipital dura were significantly thicker than the temporal dura. The occipital dura was considerably thicker than the frontal dura. The frontal and temporal dura of males were significantly thicker than females. The sagittal maximum tensile force measurements were significantly greater than transverse, for the frontal, temporal, and occipital dura. The stiffness measurements in sagittal direction were greater than the measurements in transverse direction for the frontal dura. The mechanical properties and thickness of the autogenous and artificial dura were not similar to the human dura. CONCLUSIONS: The thickness and mechanical properties of the regional cranial dura should be taken into consideration for a better cure and fewer complications. The mechanical properties of sagittal and transverse dura should be kept in mind for the preference of dura material. The present study's data can pave the way to produce artificial regional dura by mimicking the thickness and mechanical properties of the human dura.

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.

Morphometric Study of the Cervical Spinal Canal Content and the Vertebral Artery.

BACKGROUND: The morphological features of the cervical spinal nerves (C1-C8), their dimensions, and their anatomical relations with the vertebral artery are important for safe spinal surgery. The aim of the present study is to give detailed morphological data of the region to avoid complications. METHODS: Five formalin-fixed adult cadavers were studied. The cervical spinal nerves and the vertebral artery were exposed via the posterior approach, and detailed anatomy and morphometric measurements were evaluated. The following measurements were documented: angles between the spinal nerve and the spinal cord of C1 to C8, width of the C1 to C8 spinal nerves at their origin, distance of the spinal cord to the vertebral artery, number of dorsal rootlets, length of the dorsal root entry zone of C1 to C8, and distance between respective spinal nerves. Further, the average length and width of the transverse foramen were measured. RESULTS: The average angle between the spinal cord and the spinal nerve within the vertebral canal ranged between 54 and 87 degrees and were most acute at C5 (54 degrees) compared to the rest of the cervical spinal nerves. The average width of the spinal nerves (mean ± SD), was thickest at C5 (5.7 ± 1.2 mm) and C6 (5.8 ± 0.7 mm). The average largest distance between the vertebral artery and the spinal cord was at C2 (14.3 ± 1.7 mm) and the smallest at C5 (7.3 ± 0.9 mm) and C6 (7.3 ± 2.2 mm) spinal levels. The number of dorsal rootlets was most numerous at C6 (8.25 ± 0.6) and C7 (7.25 ± 0.9). The dorsal root entry zone length was the largest at C5 (13.0 ± 1.6 mm) and C6 (13.75 ± 0.5 mm). The distance between respective spinal nerves was largest between C2 and C3 (11.8 ± 2.2) and C7 and C8 (11.5 ± 0.6). CONCLUSION: The knowledge of detailed anatomy of the cervical spine (C1-C8) and its relations with the vertebral artery will reduce the unwanted damage to the vital structures of the region.

Neuroprotective effects of quercetin on cerebral vasospasm following experimental subarachnoid haemorrhage in rats

Background/aim: We examined the protective effects of the natural flavonoid, quercetin, against cerebral vasospasm in an experimental rat subarachnoid haemorrhage (SAH) model. Materials and methods: Thirty-eight albino Wistar rats were divided into five groups as follows: group 1 (G1, n=8), no experimental intervention; group 2 (G2, n=8), subarachnoid physiological saline; group 3 (G3, n=8), SAH; group 4 (G4, n=7) SAH and low-dose (10 mg/kg) quercetin treatment; group 5 (G5, n=7), SAH and high-dose (50 mg/kg) quercetin treatment. Subarachnoid haemorrhage was induced by injection of 0.15 cc of autologous blood taken from the tail artery into the cisterna magna from the craniocervical junction and basilar arteries and blood samples were taken for biochemical and histopathological analyses. Results: Malondialdehyde (MDA) levels were significantly higher in G2 and G3 than in G1 (P < 0.05). Significant decreases in MDA were observed in G4 and G5 compared with G2 (P < 0.05, G4­G2; P < 0.05, G5­G2). There were no significant differences between G2 and G3 or among G1, G4, and G5. No statistically significant differences were found in total antioxidant capacity between the groups (P > 0.05). There were no significant differences in basilar artery (BA) wall thickness between G3 and G4 or between G3 and G5, but G4 and G5 showed greater luminal diameters than G3 (P < 0.05). There were no significant differences in BA thickness or luminal diameter between G4 and G5. Conclusion: Our results suggested that quercetin may be beneficial in SAH therapy by preventing vasospasm.

Fiber dissection and 3-tesla diffusion tensor tractography of the superior cerebellar peduncle in the human brain: emphasize on the cerebello-hypthalamic fibers.

Experimental studies in various species using tract-tracing techniques showed clear evidence of the presence of cerebello-hypothalamic projections. However, these connections were not clearly described in humans. In the present study we aimed to describe the direct cerebello-hypothalamic connections within the superior cerebellar peduncle (SCP) using fiber dissection techniques on cadaveric brains and diffusion tensor tractography (DTI) in healthy adults. Fiber dissection was performed in a stepwise manner from lateral to medial on 6 cerebral hemispheres. The gray matter was decorticate and fiber tracts were revealed. The SCP was exposed and the fibers were traced distally using wooden spatulas. The MRI examinations were performed in seven cases using 3-tesla 3T unit. The direct cerebello-hyothalamic pathways were exposed using high-spatial-resolution DTI. The present study using both fiber dissection and DTI in adult human showed direct cerebello-hypothalamic fibers within the SCP. The SCP fibers course anterolateral to the cerebral aqueduct reaching the level of the red nucleus of the midbrain. The majority of the fibers crosses over and reached the contralateral diencephalic structures and some of these fibers terminated at the contralateral anterior hypothalamic area. Some of the uncrossed SCP fibers reached the ipsilateral diencephalic structures and terminated at the ipsilateral posterior hypothalamic area. We further reported the close relationship of the SCP with the MCP, lateral lemniscus, red nucleus and substantia nigra. In the DTI evaluations of the SCP we exposed unilateral left cerebello-hypothalamic fibers in five cases and bilateral cerebello-hypothalamic fibers in two cases. The present study demonstrates the direct cerebello-hypothalamic connections within the SCP for the first time using fiber dissection and DTI technique in the human brain. The detailed knowledge of the cerebello-hypothalamic fibers can outline the unexplained deficit that may occur during regional surgery.

Neuroprotective Effects of Hesperidin on Cerebral Vasospasm After Experimental Subarachnoid Hemorrhage in Rats: Biochemical, Pathologic, and Histomorphometric Analysis.

OBJECTIVE: We examined the protective effects of hesperidin on cerebral vasospasm by establishing an experimental rat model of subarachnoid hemorrhage and performing biochemical, pathologic, and histomorphometric analysis on these data. METHODS: Forty albino Wistar rats were randomly divided into 5 groups of n = 8 in each: group (G)1, no experimental interventions; G2, subjected to subarachnoid hemorrhage; G3, subjected to subarachnoid hemorrhage and administered saline (100 mg/kg); G4, subjected to subarachnoid hemorrhage and treated with low-dose hesperidin (50 mg/kg); and G5, subjected to subarachnoid hemorrhage and treated with high-dose hesperidin (100 mg/kg). Subarachnoid hemorrhage was created by injecting 0.15 cc of autologous blood taken from the rat-tail artery and injected into the cisterna magna from the craniocervical junction. Drugs were administered intraperitoneally as twice daily doses for 48 hours. Rats were euthanized at the end of this period. RESULTS: No statistically significant decrease was observed in malondialdehyde levels, which is the end-product of lipid peroxidation, among the drug groups (G4 and G5). Thin sections prepared from the basilar artery were examined morphologically. Severe luminal narrowing and vessel-wall thickening were observed in the subarachnoid hemorrhage groups (G2, G3). In the hesperidin-administered groups (G4, G5), it was determined that vessel wall thickness measurements revealed thinner walls than in the subarachnoid hemorrhage groups (G2, G3) and the luminal diameters were significantly larger than in the subarachnoid hemorrhage groups (G2, G3). CONCLUSIONS: These findings suggest that hesperidin has no effect on malondialdehyde-associated lipid-peroxidation activity; however, it might be useful in subarachnoid hemorrhage therapy because of its beneficial effects on vessel wall thickness and luminal diameters.

Spontaneous Intracystic Haemorrhage of an Arachnoid Cyst Associated with a Subacute Subdural Haematoma: A Case Report and Literature Review.

Arachnoid cysts (ACs) are congenital malformations that may develop anywhere in the subarachnoid space along the cerebrospinal axis, but are mostly observed in the temporal fossa and Sylvian fissure, predominantly on the left side. ACs account for 1% of all intracranial space-occupying lesions. ACs are potential risk factors for subdural haematoma in all age groups following a traumatic head injury. Although an intracystic haemorrhage of AC without evidence of a head trauma is very rare, it may particularly develop in children and young adults who spend much more time engaged in games and forced physical exercises. Here we present a rare case of spontaneous intracystic haemorrhage of AC with a subacute subdural haematoma and provide a review of the literature.

Cortical, subcortical and brain stem connections of the cerebellum via the superior and middle cerebellar peduncle in the rat.

The role of cerebellum in coordination of somatic motor activity has been studied in detailed in various species. However, experimental and clinical studies have shown the involvement of the cerebellum with various visceral and cognitive functions via its vast connections with the central nervous system. The present study aims to define the cortical and subcortical and brain stem connections of the cerebellum via the superior (SCP) and middle (MCP) cerebellar peduncle using biotinylated dextran amine (BDA) and Fluoro-Gold (FG) tracer in Wistar albino rats. 14 male albino rats received 20-50-nl pressure injections of either FG or BDA tracer into the SCP and MCP. Following 7-10 days of survival period, the animals were processed according to the related protocol for two tracers. Labelled cells and axons were documented using light and fluorescence microscope. The SCP connects cerebellum to the insular and infralimbic cortices whereas, MCP addition to the insular cortex, it also connects cerebellum to the rhinal, primary sensory, piriform and auditory cortices. Both SCP and MCP connected the cerebellum to the ventral, lateral, posterior and central, thalamic nuclei. Additionally, SCP also connects parafasicular thalamic nucleus to the cerebellum. The SCP connects cerebellum to basal ganglia (ventral pallidum and clastrum) and limbic structures (amygdaloidal nuclei and bed nucleus of stria terminalis), however, the MCP have no connections with basal ganglia or limbic structures. Both the SCP and MCP densely connects cerebellum to various brainstem structures. Attaining the knowledge of the connections of the SCP and MCP is important for the diagnosis of lesions in the MCP and SCP and would deepen current understanding of the neuronal circuit of various diseases or lesions involving the SCP and MCP.

Coexistence of cervico-thoracic extradural en-plaque meningioma with multiple intracranial meningiomas.

Meningioma is one of the most common tumors in the spinal cord. Extradural and en-plaque variety of meningioma occur less frequently. A 47-year-old woman is presented with radiculopathy signs. Magnetic resonance imaging revealed a lesion from C6 through T3 vertebral levels compressing the cord both anteriorly and posteriorly. Subtotally excision was performed and histopathologic signs showed transitional type of meningioma (WHO Grade 1). Post operatively, she had good neurological recovery. Intraoperative findings point out that the en-plaque meningioma was pure extradural. Twelve cases of pure extradural en-plaque meningioma have been reported in the literature. Besides, to the best our knowledge coexistence of "en plaque" spinal epidural meningioma with meningiomas in cranial cavity has not been reported. Complete resection is mandatory to prevent recurrence. Moreover, it is considerably difficult to remove the parts of tumor over anterior of the dura without complication.