Recai Tuncer

CT angiography and perfusion imaging in patients with subarachnoid hemorrhage: correlation of vasospasm to perfusion abnormality

IntroductionWe retrospectively evaluated computed tomography angiography (CTA) and perfusion imaging (CTP) of patients with aneurysmal subarachnoid hemorrhage (SAH) for any correlation between degree of vasospasm and perfusion deficit.Materials and methodsSequentially performed CTP and CTA of 41 patients at least at the third day of postbleeding were reviewed for vasospasm and perfusion deficit throughout the anterior and middle cerebral arteries and corresponding territories. Vasospasm was noted comparing the contralateral normal ones or extradural components of the vessel itself and graded to negative, mild, moderate, and severe as luminal narrowing none, <25%, between 25% and 50%, and ≥50%, respectively. CTP abnormality was noted using cerebral blood flow and volume and mean transit time maps.ResultsOf 41 patients, 20 had no vasospasm; 15 had mild to moderate and six had severe vasospasm. Three of 20 patients with no vasospasm (15%), four of 15 patients with mild to moderate vasospasm (26%), and five of six patients with severe vasospasm (83%) had perfusion abnormality. Perfusion abnormalities noted were ischemia, infarction, and hyperperfusion. Perfusion abnormality without vasospasm was observed in the watershed areas and adjacent to sulcal clots.ConclusionIn SAH patients, if there is a macrovascular vasospasm with luminal narrowing ≥50%, there is a high likelihood (83%) of perfusion abnormality in the territory of the vasospastic vessel. There may also be perfusion abnormality without macrovascular vasospasm in the watershed areas or in the vicinity of sulcal clots.

Complications of closed continuous lumbar drainage of cerebrospinal fluid.

Summary. Sixty three patients who had a lumbar subarachnoid catheter placed for closed continuous cerebrospinal fluid drainage and the complications are presented. The drain was successful in achieving the desired goal in 59 patients (93,6%). The complications are mainly divided into 3 groups; A – complications related to alterations in CSF drainage rate, B – complications due to mechanical failure of the catheter, C – infection. The overall complication rate is found to be 44,4%. Overdrainage, pneumocephalus and meningitis are found to be the most severe complications, but most of these complications are reversible with early recognition. Unfortunately one patient died following meningitis and hepatic failure. Lumbar subarachnoid drainage is a safe method unless the development of any neurological findings should prompt rapid discontinuation of lumbar drainage and immediate radiographic evaluation.

The effect of condylectomy on extreme lateral transcondylar approach to the anterior foramen magnum

SummaryThe dorsolateral, suboccipital, transcondylar technique was used in this cadaveric study. The angle and distance measurements in the corridors were taken intradurally both superior and inferior of the foramen magnum level. In the first stage of this study, the findings which were gained from the standard lateral suboccipital approach were compared with the findings after condyle and lateral atlantal mass removal. After condylectomy, the approach to anterior foramen magnum via both corridors was found to be shorter and the lateral angle of the exposure of the anterior foramen magnum was found to be wider. The considerable shortening of the distances to the anterior foramen magnum, especially in the superior corridor, emphasises the necessity of combining standard approaches with condylectomy. In addition, it was found that after condylectomy, considerable widening of both transverse and longitudinal planes in the inferior corridor allows the surgeon greater access to work on lesions. Furthermore, the freed space between the superior corridor and the inferior corridor, which was gained by condylectomy, shows that condylectomy provides a combined approach to the inferior and superior parts of the foramen magnum anteriorly.

Anatomical evaluation of the groove for the vertebral artery in the axis vertebrae for atlanto-axial transarticular screw fixation technique

Anatomical measurements were studied on 40 dry axis vertebrae to determine the suitability of the groove for the vertebral artery for atlanto‐axial transarticular screw fixation technique. We measured 13 parameters including three angular and 10 linear dimensions related to the groove of the vertebral artery, pedicle, and pars interarticularis and evaluated 80 measurements for each parameter. All measurements were done after placing a Kischner guide wire through the pedicle. We found that differences between measurements on the left and right sides of each vertebra were nonsignificant. In spite of the variability in measurements such as height, width, and median angle of the pedicle, the decline angle for instrumentation, the depth of the groove for the vertebral artery, and the internal height of the pars interarticularis, all of these had good symmetry. However, there were statistically significant differences between the sides in measurements for both the width (P=0.05) and the angle (P<0.02) of the pedicle allowing instrumentation and they did not show good symmetry. The risk of vertebral artery injury was found to be 22.5% per specimen, or 16.25% per screw inserted because the internal height of the pars interarticularis at point of fixation was ≤ 2.1 mm. In addition, we found that the pedicle width allowing instrumentation was not suitable in 12.5% of screws inserted because their values were ≤ 6 mm. When the width of the pedicle for instrumentation and the internal height of the pars interarticularis were both evaluated together, we also found that this technique would be extremely dangerous in 7.5% of specimens. In conclusion, the internal height of the pars interarticularis and the width of the pedicle for instrumentation should be evaluated together in thin CT sections preoperatively, because of the risk of vertebral artery injury in patients upon which atlanto‐axial transarticular screw fixation is to be performed. Clin. Anat. 13:237–243, 2000.

The effects of fenestration of the interpeduncular cistern membrane arousted to the opening of lamina terminalis in patients with ruptured ACoA aneurysms: a prospective, comparative study

SummaryBackground. The incidence of chronic hydrocephalus requiring shunt placement is a well-known and common complication of aneurysmal subarachnoid hemorrhage (aSAH). It was suggested that fenestration of the lamina terminalis (LT) during microsurgery for aSAH may be associated with a reduced rate of shunt-dependent chronic hydrocephalus (SDCH). We analyzed that, fenestrations of the LT and Liliequist membrane (LM) would reduce rate of SDCH and improve rate of favorable outcome. Methods. 145 patients who were analyzed in the study were treated in our department with ruptured anterior communicating artery (ACoA) aneurysms. We compared the rate of shunting and clinical outcome in patients in whom only fenestration of the LT (Group 1) was performed with that in patients in whom fenestrations of both the LT and LM (Group 2) were performed. Results. Chronic hydrocephalus requiring shunting amounted to 9.8% (7 patients) in Group 1 and 4% (3 patients) in Group 2 (p = 0.203). Also, there were no differences in the rate of shunt dependent hydrocephalus between the two groups in patients with Fisher’s CT grades 3 (p = 0.343) and 4 (p = 0.667), and HH grades 4 (p = 0.306) and 5 (p = 0.361). Favorable clinical outcomes were observed with rates of 74.6% in Group 1 and 79.7% in Group 2 (p = 0.693). Also there were no differences in the rates of favorable clinical outcome between the two groups in patients with Fisher’s CT grades 3–4, HH grades 4–5. Conclusions. Our study shows that fenestration of the LM coupled with the opening of the LT reduced-relatively-the incidence of SDCH; this however was not significant. This positive effect was particularly noticeable in patients in whom a cisternal “overflow” was observed at surgery when opening the LM. This corresponded to cases with ventricular dilatation and a IVth ventricle with clots.

Angiographic follow-up after surgical treatment of intracranial aneurysms

SummaryThis study was undertaken to evaluate the long-term angiographic outcome of surgically treated aneurysms. In addition, the incidence of recurrent aneurysms, the fate of residual aneurysms and the de novo formation of aneurysms were evaluated. Moreover, morphological conditions such as dilatation, stenosis or irregularity in temporarily clipped vascular segments were analyzed.166 aneurysms were operated on in 136 patients and these 166 aneurysms subsequently underwent late follow-up angiography. Late angiographic follow-up review was obtained at a mean of 46.6±11.5 months postsurgery (range 36–85 months). Out of the 7 aneurysms with known residua, 5 residual aneurysms were determined as unchanged, 1 residual aneurysm as spontaneous thrombosis and 1 residual aneurysm as enlarged. No recurrent aneurysm was found, however two de novo aneurysms were found. During the surgery of 85 anuerysms, 137 vascular segments clipped temporarily were evaluated in terms of morphological changes in postoperative and long-term angiograms. No morphological changes were determined in any vascular segments.These anatomical long-term results confirm the long-term efficacy of aneurysm clipping, when perfect. Small residual aneurysms can be followed with periodically performed angiography.

Effect of early bilateral decompressive craniectomy on outcome for severe traumatic brain injury.

AIM Debate continues as to whether decompressive craniectomy (DC) is an effective treatment for severe traumatic brain injury (STBI). DC is mostly used as a second tier treatment option. The aim of this study was determined whether early bilateral DC is effective as a first tier treatment option in patients with STBI. MATERIAL AND METHODS The study compared two groups. Group 1 comprised 36 STBI patients for whom control of intracranial pressure (ICP) was not achieved with conservative treatment methods according to radiological and neurological findings. These patients underwent bilateral or unilateral DC as a second tier treatment. Group 2 comprised 40 STBI patients who underwent early bilateral DC as a first tier treatment. RESULTS Group 2 patients had a mean better outcome than Group 1 patients especially for patients with a GCS 6-8. Postoperative ICP was lower in Group 2 patients than Group 1 patients. CONCLUSION This study indicates that early bilateral DC can be effective for controlling ICP in STBI patients. It is likely the favorable outcome results for Group 2 patients reflects the relatively short time between trauma and surgery. Therefore, these data indicate early bilateral DC can be considered as a first tier treatment in STBI patients.

Intra-operative brain tumor detection using elastic light single-scattering spectroscopy: a feasibility study

We have investigated the potential application of elastic light single-scattering spectroscopy (ELSSS) as an adjunctive tool for intraoperative rapid detection of brain tumors and demarcation of the tumor from the surrounding normal tissue. Measurements were performed on 29 excised tumor specimens from 29 patients. There were 21 instances of low-grade tumors and eight instances of high-grade tumors. Normal gray matter and white matter brain tissue specimens of four epilepsy patients were used as a control group. One low-grade and one high-grade tumor were misclassified as normal brain tissue. Of the low- and high-grade tumors, 20 out of 21 and 7 out of 8 were correctly classified by the ELSSS system, respectively. One normal white matter tissue margin was detected in a high-grade tumor, and three normal tissue margins were detected in three low-grade tumors using spectroscopic data analysis and confirmed by histopathology. The spectral slopes were shown to be positive for normal white matter brain tissue and negative for normal gray matter and tumor tissues. Our results indicate that signs of spectral slopes may enable the discrimination of brain tumors from surrounding normal white matter brain tissue with a sensitivity of 93% and specificity of 100%.

Primary primitive neuro-ectodermal tumor of cauda equina with intracranial seeding.

SummaryPrimitive neuro-ectodermal tumor (PNET) of the cauda equina is a rare entity. 18 cases have been reported in the literature so far, including 4 cases with intracranial seeding. Moreover parenchymal involvement of brain has never been reported as a form of intracranial seeding from PNET of the cauda equina. A 31 year-old female patient, with PNET of cauda equina showing intracranial seeding 6 months after surgery, is presented in this report. To our knowledge, this is the first adult case of spinal cord PNET with parenchymal involvement of brain. The histopathological, clinical and radiological findings as well as treatment of the patient were evaluated.

Post-traumatic bilateral diffuse cerebral swelling

SummaryThis study confirms that bilateral diffuse cerebral swelling with or without parenchymal haemorrhages (< 15 cc) is a more common occurrence in the paediatric patients with severe head injury as compared with adults, since the analysed sample represented 42.55% and 20.43% of all paediatric and adult patients with severe head injury recorded in our clinic at the time of the study, respectively. The incidence of patients with diffuse cerebral swelling without parenchymal haemorrhages was found to be 27.65% of paediatric patients and 5.37% of adult patients with severe head injury. Secondary neurological deterioration occurred only in 5 (12.5%) paediatric patients and in 4 (10.5%) adult patients with diffuse cerebral swelling and was not to be found associated with parenchymal haemorrhages. A better outcome was seen in paediatric patients. Mortality rates were 12.5% in paediatric patients and 34.21% in adult patients. Our data also suggest that the mortality rate between paediatric and adult patients with diffuse cerebral swelling without parenchymal haemorrhages was similar (15.38% and 20% in paediatric and adult group, respectively), while the adult patients with diffuse cerebral swelling associated with small intraparenchymal haemorrhages have a worse prognosis than paediatric patients.