Management and Outcome of Intracranial Dural Arteriovenous Fistulas That Have Caused a Hemorrhage in the Posterior Fossa : A Clinical Study.

OBJECTIVE: We evaluated the diagnosis, treatment, and long-term results of patients with dural arteriovenous fistula (dAVF), which is a very rare cause of posterior fossa hemorrhage. METHODS: This study included 15 patients who underwent endovascular, surgical, combined, or Gamma Knife treatments between 2012 and 2020. Demographics and clinical features, angiographic features, treatment modalities, and outcomes were analyzed. RESULTS: The mean age of the patients was 40±17 years (range, 17-68), and 68% were men (11/15). Seven of the patients (46.6%) were in the age group of 50 years and older. While the mean Glasgow coma scale was 11.5±3.9 (range, 4-15), 46.3% presented with headache and 53.7% had stupor/coma. Four patients (26.6%) had only cerebellar hematoma and headache. All dAVFs had cortical venous drainage. In 11 patients (73.3%), the fistula was located in the tentorium and was the most common localization. Three patients (20%) had transverse and sigmoid sinus localizations, while one patient (6.7%) had dAVF located in the foramen magnum. Eighteen sessions were performed on the patients during endovascular treatment. Sixteen sessions (88.8%) were performed with the transarterial (TA) route, one session (5.5%) with the transvenous (TV) route, and one session (5.5%) with the TA+TV route. Surgery was performed in two patients (14.2%). One patient (7.1%) passed away. While there were nine patients (64.2%) with a Rankin score between 0 and 2, the total closure rate was 69.2% in the first year of control angiograms. CONCLUSION: In the differential diagnosis of posterior fossa hemorrhages, the differential diagnosis of dAVFs, which is a very rare entity, should be considered, even in the middle and elderly age groups, in patients presenting with good clinical status and pure hematoma. The treatment of such patients can be done safely and effectively in a multidisciplinary manner with a good understanding of pathological vascular anatomy and appropriate endovascular treatment approaches.

Influence of galantamine on peripheral nerve degeneration after experimental compression injury of the rat sciatic nerve.

BACKGROUND: Galantamine is well-known for its neuroprotective effects and is currently used in the treatment of individuals with Alzheimer's disease. In this study, we induced experimental sciatic nerve injury (SCI) in rats to test the beneficial effects of galantamine. METHODS: Thirty male Wistar albino rats were divided into three groups, as follows: sham, SCI + saline, and SCI + galantamine. After the administration of an intraperitoneal ketamine and xylazine mixture, which was used for anesthesia, SCI was induced by sur-gical clip compression at the midthigh region of the rats. After surgery, a single daily intraperitoneal dose of galantamine was adminis-tered for 7 days, and nerve tissue sections were obtained 1 week after injury. Histopathology studies were performed to assess neural thickness and apoptotic cell counts, and light microscopic morphological examination was used to determine a potential beneficial effect of galantamine on peripheral nerve degeneration. RESULTS: We observed a markedly increased microvasculature, increased nerve fiber thickness, and a statistically significant increase in apoptotic cell counts distal to the level of injury in the saline group compared with the sham group. However, the increases in nerve fiber thickness and apoptotic cell counts were less in the galantamine group compared with the saline group. CONCLUSION: In our experimental model, pharmacological intervention with galantamine demonstrated a protective effect on degeneration after peripheral nerve injury.

Comparison of Histological and Angiographic Measurements of the Basilar Artery in an Experimental Rabbit Subarachnoid Hemorrhage Model.

AIM: To compare the histological and angiographic measurements of the basilar artery in an experimental rabbit subarachnoid hemorrhage model. MATERIAL AND METHODS: The basilar artery was measured using both histological and angiographic methods in experimental subarachnoid hemorrhage (SAH) and vasospasm rabbit models. New Zealand white rabbits were randomly categorized into two groups: control and SAH groups. The SAH group rabbits were operated on to create an experimental SAH. Both groups were examined angiographic and histological methods. RESULTS: On comparing the two methods, angiographic and histopathological measurements of the basilar artery were similar in the control group. However, in the SAH group, the difference between the angiographic and histopathological measurement methods was significant. Histopathological measurements of the basilar artery were lower than angiographic measurements, and the difference was statistically significant. In the angiographic method, although there was a marked decrease in basilar artery measurements in the SAH group, the differences between the groups was not statistically significant. However, in the histopathological method, measurement differences between the control and SAH groups were statistically significant. CONCLUSION: Histopathological measurements were shown to be more sensitive than angiographic methods in demonstrating cerebral vasopasm in experimental SAH rabbit models.

Initial Discectomy Associated with Aging Leading to Adjacent Disc Disease and Recurrence.

AIM: Failure of surgery for lumbar disc herniation (LDH) can be commonly caused by recurrence. There are many debates regarding the risk factors of recurrent LDH (rLDH) and it is very difficult to define them because many clinical and complicated biomechanical parameters are involved. The purpose of study was to evaluate the long term result of re-discectomy for LDH at the same level and adjacent segments. MATERIAL AND METHODS: Between 1999 and 2009, 1898 cases were operated and 142 (6.4%) patients underwent re-discectomy following initial operation. The study included 65 patients who were operated for single level discectomy, and their charts were analyzed retrospectively. RESULTS: There were 33 (50.8%) women and mean age was 45.5 years (24-73 years). rLDH was diagnosed at the initial level in 40 (61.5%) but adjacent and/or opposite level herniation (with or without the first level) was found in the remaining 25 cases (39.1%). Recurrence at the same level (SLG) and adjacent level groups (ALG) were similar according to the clinical outcomes in follow-up (mean 34.1 months). Admission period after initial operation was also parallel in SLG and ALG (54.7 and 53.1 months, respectively). However, the mean age of ALG (49.4 years) was significantly higher (p≤0.05) than SLG (42.8 years). CONCLUSION: After discectomy, collapsed discs are biomechanically more stable than those with preserved disc heights, and responses to axial compression on intervertebral disc pressure produced deformations of adjacent levels despite limitations. Altered biomechanical loading next to a fusion resulted in ongoing degeneration with aging at the affected entire lumbar spine.

Biochemical and histopathological effects of catechin on experimental peripheral nerve injuries.

AIM: Catechin is a type of polyphenol, along with epicatechin, epigallocatechin, and epigallocatechin-gallate (EGCG). This study aims to investigate the effect of EGCG, a major metabolite of catechin, which is the principle bioactive compound in green tea, on rats with peripheral nerve injury. MATERIAL AND METHODS: A total of 74 rats were divided into six groups, namely the control, the trauma, the normal saline, a 25mg/kg EGCG, a 50mg/kg EGCG and a daily consumption group (10mg/kg EGCG was given intraperitoneally for 14 days before the trauma). Except the first group, the other groups underwent a 1-minute sciatic nerve compression by clip with 50gr/cm2 pressure. Nerve samples were obtained at 28 day after trauma for the biochemical and histopathological analysis. RESULTS: Our study showed that the Daily consumption, 25mg/kg EGCG and 50mg/kg EGCG groups demonstrated statistically significant decreased lipid peroxidation levels and particularly daily consumption, and the 25mg/kg EGCG group showed a favourable reduction of degeneration and edema histologically. CONCLUSION: This study shows that Catechin and its derivatives have a protective effect on peripheral nerve injury.

Tobacco-induced neuronal degeneration via cotinine in rats subjected to experimental spinal cord injury.

OBJECTIVES: Cigarette smoke contains over 4000 chemicals including well-characterized toxicants and carcinogens, among which is cotinine. Cotinine is the principal metabolite of nicotine that has adverse affects on the microcirculation via vasoconstriction, hypoxia and the wound-healing cascade. Its impact on spinal cord injury (SCI) has not been investigated yet. The aim of the present study is to investigate the cotinine effect on SCI. METHODS: 48 male Wistar rats were divided into six groups as follows: sham-control, sham-trauma, vehicle-control, vehicle-trauma, cotinine-control, and cotinine-trauma. Initially, a defined concentration of cotinine blood level was maintained by daily intraperitoneal injection of cotinine for 14 days in the cotinine groups. The concentration was similar to the cotinine dose in the blood level of heavy smokers. Only ethyl alcohol was injected in the vehicle groups during the same period. Then, SCI was performed by a Tator clip. The cotinine groups were compared with rats subjected to vehicle and sham groups by immunohistochemical biomarkers such as glial fibrillary acidic protein (GFAP) and 2,3-cyclic nucleotide 3-phosphodiesterase (CNP) expressions. Electron microscopic examination was also performed. RESULTS: GFAP-positive cells were noted to be localized around degenerated astrocytes. Marked vacuolization with perivascular and perineural edema was seen in the cotinin consumption groups. These findings showed the inhibition of regeneration after SCI. Similarly, vacuolization within myelin layers was noted in the cotinine groups, which was detected through reduced CNP expression. CONCLUSION: Cotinine, a main metabolite of nicotine, has harmful effects on SCI via GFAP and CNP expression. The findings of the present study support the hypothesis that tobacco causes neuronal degeneration via cotinine.

Dural sinus thrombosis following head injury: report of two cases and review of the literature.

Dural sinus thrombosis (DST) usually involves the sagittal, transverse and sigmoid sinuses and is more common in women due to pregnancy, puerperium and oral contraceptive use. Other etiologies include coagulopathies, infection and head injury. We have present two DST cases following head injury. The first case was a 35-year-old man hospitalized because of one-week history of headache and repeated vomiting after a mild head injury. Thrombosis of the superior sagittal sinus, right transverse and sigmoid sinuses and right jugular vein was determined on angiography. The second case was a 25- year-old man operated on for epidural hematoma at the posterior fossa. Meningitis developed and an abducens palsy was determined. Magnetic resonance imaging demonstrated thrombosis of the right transverse and sigmoid sinus. Low molecular weight heparin was administrated for three months. Both cases had good recovery, but one had recanalisation of the thrombosis. Intracranial hematomas, depressed skull fracture or skull fracture that cross the sinus can obstruct the blood flow in the sinus. Moreover, closed head injury may cause to DST. Because of undefinitive pathophysiology, a consensus was not obtained on overall strategy concerning conservative, radiosurgical, or surgical therapy yet.