Altay Sencer

Surgical results in pediatric Spetzler–Martin grades I–III intracranial arteriovenous malformations

ObjectsThe goal of cerebral arteriovenous malformation (AVM) therapy in pediatric patients should be complete resection or obliteration of the AVM to eliminate subsequent hemorrhage, because of high mortality and morbidity rates related to hemorrhage in addition to the longer life expectation. Despite advances in Gamma knife radiosurgery and in endovascular embolization, surgical resection is still the gold standard for treating cerebral AVMs.MethodsBetween 1986 and 2003, 20 children were surgically treated for cerebral AVMs. The AVMs were graded I, II, and III using the Spetzler–Martin (S–M) Grading Scale. Good recovery was achieved in 18 out of 20 patients (90%) and only 1 patient was moderately disabled (5%). There was one mortality (5%) related to the preoperative deep comatose state of the patient. The total obliteration rate was 89% (17 out of 19).ConclusionFor S–M grade I–III AVMs, surgical resection is the treatment of choice, considering its high cure rate and low morbidity and mortality rates.

Treatment of ruptured blood blister-like aneurysms with flow diverter SILK stents

Introduction Blood blister-like aneurysms (BBAs) are fragile and difficult to treat. Routine surgical and endovascular treatment methods, such as clipping, clip wrapping, primary coiling, or stent assisted coiling, have relatively high morbidity and mortality rates. In this study, we report clinical and angiographic results for treatment of ruptured BBAs using flow diverter stents. Methods We retrospectively reviewed patients who presented with subarachnoid hemorrhages caused by rupture of BBAs and who were treated using flow diverter stents at three neurointervention centers between January 2009 and January 2013. Clinical and angiographic findings, together with the procedural data and follow-up results, are reported. Results 11 patients were identified in this study. BBAs were located on the supraclinoid internal carotid artery (nine patients) and basilar arteries (two patients). Eight patients were treated by implantation of a single flow diverter stent. Two flow diverter stents were telescopically deployed in each of three patients. The procedures were successful in all cases. No acute complications developed in any case. One patient who had an initial Hess–Hunt grade 4 died of septicemia 2 weeks after the procedure (9%). Another patient developed a minor stroke caused by parent artery thrombosis (9%). Control angiographies performed 3 and 6 months post stenting revealed complete occlusion of the aneurysms in all of the remaining nine patients (82%). 10 of the 11 patients (92%) had good clinical outcomes (modified Rankin Scale score ≤2). Conclusions Implantation of flow diverter stents seems to be a safe and feasible alternative for treatment of ruptured BBAs.

LOCALIZATION OF CEREBROSPINAL FLUID LEAKS BY GADOLINIUM-ENHANCED MAGNETIC RESONANCE CISTERNOGRAPHYA 5-YEAR SINGLE-CENTER EXPERIENCE

OBJECTIVEIntrathecal gadolinium (Gd)-enhanced magnetic resonance (MR) cisternography is a newly introduced imaging method. Two main objectives of this study were to investigate the sensitivity of Gd-enhanced MR cisternography for presurgical localization of cerebrospinal fluid (CSF) leaks in patients with CSF rhinorrhea and to study the potential long-term adverse effects of intrathecal Gd application. METHODSFifty-one patients (19 women; mean age, 36.2 yr) with CSF rhinorrhea were included in the study. A total of 0.5 ml of Gd was injected into the lumbar subarachnoid space. T1-weighted MR cisternographic images were obtained to detect CSF leakage. The patients neurological states and vital signs were recorded for the first 24 hours after the procedure. Neurological evaluations were repeated 1, 3, and 12 months after the procedure. The patients were followed for at least 3 years with annual neurological examinations. RESULTSGd-enhanced MR cisternography demonstrated CSF leaks in 43 of the 51 patients. The sensitivity of Gd-enhanced MR cisternography for localization of CSF leaks was 84%. Forty-four patients underwent surgery to repair dural tears. Surgical findings confirmed the results of Gd-enhanced cisternography in 43 of the 44 patients who underwent surgery (98%). Eight patients with negative Gd-enhanced MR cisternography had no active rhinorrhea at the time of procedure, and seven of them did not need surgery. None of the patients developed an acute adverse reaction that could be attributed to the procedure. None of the patients developed any neurological symptoms or signs caused by intrathecal Gd injection during a mean follow-up period of 4.12 years. CONCLUSIONGd-enhanced MR cisternography is a sensitive and safe imaging method for detection of CSF leaks in patients with rhinorrhea.

Stereotactic surgery in the management of brain abscess

BACKGROUND Bacterial brain abscesses can be diagnosed and treated with stereotactic aspiration. METHODS From 1991 to 1997 we have used computed tomography-guided stereotactic aspiration to diagnose and treat 21 patients with a total of 58 bacterial brain abscesses. The ages of the patients ranged from 4 to 72 years (median 25 years); 11 of these 21 patients had multiple abscesses. The number of abscesses per patient with multiple abscesses ranged from 2 to 9, all located deep in subcortical white matter. RESULTS All patients underwent stereotactic surgical drainage and an 8-week intravenous antibiotic medical treatment. Of the 58 abscesses, 23 were aspirated. Of these 23 abscesses, 19 were radiologically stage III or IV and four were stage I or II. Pathological examination confirmed radiological staging in 19 patients (83%). Except for the three patients who have mild residual hemiparesis and one patient recovering from ataxia, all patients had complete neurological recovery. CONCLUSIONS Computed tomography-guided stereotaxy achieved all the objectives of management; namely, ascertaining the diagnosis, draining the content of the mass, and obtaining pus for accurate bacteriological diagnosis without morbidity. Stereotactic aspiration combined with an 8-week intravenous antibiotic regimen has yielded an effective therapeutic result in all of our abscesses, small or large, solitary or multiple, superficial or deep-seated. A high radiological-pathological correlation was also deduced from this study.

Fully Endoscopic Interlaminar and Transforaminal Lumbar Discectomy: Short-Term Clinical Results of 163 Surgically Treated Patients

OBJECTIVE To evaluate the clinical outcomes of patients with lumbar disc disease undergoing fully endoscopic surgery at a single clinic. METHODS Between August 2009 and January 2012, 163 patients (74 men and 89 women) underwent fully endoscopic lumbar discectomy. All patients were followed for 1 year after surgery. The Oswestry Disability Index and a visual analog scale were used to analyze outcomes. RESULTS During the follow-up period, 114 (70%) patients had no complaints, 30 (18%) patients had occasional pain, and 19 (12%) patients had no improvement. During postoperative follow-up, 8 patients required repeat surgery for recurrence or residual fragments. Postoperatively, 4 patients experienced dysesthesia, which completely resolved in time. Neurologic deterioration occurred in 5 patients, 4 of whom recovered completely without any intervention. Dural tears occurred in 6 patients. CONCLUSIONS Fully endoscopic interlaminar or transforaminal surgeries are safe and effective treatment modalities for lumbar disc herniations. Despite the difficulties of acquiring this new technique, good results can be achieved with sufficient experience.

Effect of magnesium, MK-801 and combination of magnesium and MK-801 on blood–brain barrier permeability and brain edema after experimental traumatic diffuse brain injury

Abstract Objective: Glutamate antagonists are very attractive drugs in laboratory works to protect neural tissue against ischemia. In this work, the effects of magnesium, MK-801 and combination of magnesium and MK-801 on blood–brain barrier (BBB) and brain edema after experimentally induced traumatic brain injury are evaluated. Methods: A standard closed head injury was induced on the rats by a controlled impact device using a 450-g free falling mass from a height of 2 m onto a metallic disc fixed to the intact skull. One of the following was injected to animals intraperitoneally 30 minutes after injury: saline, magnesium, MK-801 and magnesium plus MK-801. To quantify the brain edema, the specific gravity of the brain tissue was determined. To demonstrate the alteration of the BBB permeability, Evans blue dye was used as a tracer. Results: In all treatment groups, the specific gravity of brain tissue values was significantly higher compared with the control group. Evans blue dye content in the brain tissue was significantly reduced in all three treatment groups with respect to the control group. There was no significant difference of effect between the groups of magnesium alone and MK-801 alone when compared with each other and when compared with their combination. Conclusion: The present data demonstrate that treatment with magnesium, MK-801 and combination of magnesium and MK-801 can reduce formation of brain edema and can help restore BBB permeability after experimental diffuse brain injury.

Traumatic epidural hematomas of the posterior cranial fossa

BACKGROUND Traumatic EDHs of the posterior cranial fossa are rare and have a higher mortality than supratentorial localizations. Early diagnosis of TEHPCF and prompt surgical evacuation provide excellent recovery. Active use of cranial CT scanning has taken a major role in the diagnosis, surgical indication, close observation, and strategy planning. As a result, better prognosis is achieved. In this study, we represent our results and experiences in the management of TEHPCF. METHODS Between 1993 and 2006, 65 patients with TEHPCF were treated in Istanbul University Faculty Of Medicine, Neurosurgery and Emergency Surgery Departments. The hospital records of these patients were analyzed retrospectively. RESULTS Of 65 patients, whose diagnosis and management decisions were determined by cranial CT scans, 53 were treated through surgery and 12 by conservative methods. Of the 53 surgically treated patients, 2 (3%) patients died, and 2 (3%) other patients remained moderately disabled during their discharge. As a result, 61 (94%) of 65 patients had excellent recovery. CONCLUSION When compared with the literature, our mortality rate was superior to other previously reported studies. In our opinion, this is a result of extensive use of the cranial CT scan together with aggressive surgery. Patients with occipital trauma should be evaluated using cranial CT scans, and those showing mass effect should be immediately treated surgically. The patients that have no mass effect on CT scans can be closely observed by planned serial control CT scans.

Exploring the time-frequency content of high frequency oscillations for automated identification of seizure onset zone in epilepsy

OBJECTIVE High frequency oscillations (HFOs) in intracranial electroencephalography (iEEG) recordings are considered as promising clinical biomarkers of epileptogenic regions in the brain. The aim of this study is to improve and automatize the detection of HFOs by exploring the time-frequency content of iEEG and to investigate the seizure onset zone (SOZ) detection accuracy during the sleep, awake and pre-ictal states in patients with epilepsy, for the purpose of assisting the localization of SOZ in clinical practice. APPROACH Ten-minute iEEG segments were defined during different states in eight patients with refractory epilepsy. A three-stage algorithm was implemented to detect HFOs in these segments. First, an amplitude based initial detection threshold was used to generate a large pool of HFO candidates. Then distinguishing features were extracted from the time and time-frequency domain of the raw iEEG and used with a Gaussian mixture model clustering to isolate HFO events from other activities. The spatial distribution of HFO clusters was correlated with the seizure onset channels identified by neurologists in seven patient with good surgical outcome. MAIN RESULTS The overlapping rates of localized channels and seizure onset locations were high in all states. The best result was obtained using the iEEG data during sleep, achieving a sensitivity of 81%, and a specificity of 96%. The channels with maximum number of HFOs identified epileptogenic areas where the seizures occurred more frequently. SIGNIFICANCE The current study was conducted using iEEG data collected in realistic clinical conditions without channel pre-exclusion. HFOs were investigated with novel features extracted from the entire frequency band, and were correlated with SOZ in different states. The results indicate that automatic HFO detection with unsupervised clustering methods exploring the time-frequency content of raw iEEG can be efficiently used to identify the epileptogenic zone with an accurate and efficient manner.

Neuronal autoantibodies in mesial temporal lobe epilepsy with hippocampal sclerosis

Objective Our aim was to investigate the prevalence of neuronal autoantibodies (NAbs) in a large consecutive series with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and to elucidate the clinical and laboratory clues for detection of NAbs in this prototype of frequent, drug-resistant epilepsy syndrome. Methods Consecutive patients diagnosed with MTLE fulfilling the MRI criteria for HS were enrolled. The sera of patients and various control groups (80 subjects) were tested for eight NAbs after ethical approval and signed consents. Brain tissues obtained from surgical specimens were also investigated by immunohistochemical analysis for the presence of inflammatory infiltrates. The features of seropositive versus seronegative groups were compared and binary logistic regression analysis was performed to explore the differentiating variables. Results We found antibodies against antigens, contactin-associated protein-like 2 in 11 patients, uncharacterised voltage-gated potassium channel (VGKC)-complex antigens in four patients, glycine receptor (GLY-R) in 5 patients, N-methyl-d-aspartate receptor in 4 patients and γ-aminobutyric acid receptor A in 1 patient of 111 patients with MTLE-HS and none of the control subjects. The history of status epilepticus, diagnosis of psychosis and positron emission tomography or single-photon emission CT findings in temporal plus extratemporal regions were found significantly more frequently in the seropositive group. Binary logistic regression analysis disclosed that status epilepticus, psychosis and cognitive dysfunction were statistically significant variables to differentiate between the VGKC-complex subgroup versus seronegative group. Conclusions This first systematic screening study of various NAbs showed 22.5% seropositivity belonging mostly to VGKC-complex antibodies in a large consecutive series of patients with MTLE-HS. Our results indicated a VGKC-complex autoimmunity-related subgroup in the syndrome of MTLE-HS.

Whole mitochondrial DNA variations in hippocampal surgical specimens and blood samples with high-throughput sequencing: A case of mesial temporal lobe epilepsy with hippocampal sclerosis

INTRODUCTION Hippocampal sclerosis is the most common lesion in patients with mesial temporal lobe epilepsy. Recently, there has been growing evidence on the involvement of mitochondria also in sporadic forms of epilepsy. In addition, it has been increasingly argued that mitochondrial dysfunction has an important role in epileptogenesis and seizure generation in temporal lobe epilepsy. Although mtDNA polymorphisms have been identified as potential risk factors for neurological diseases, the link between homoplasmy and heteroplasmy within tissues is not clear. We investigated whether mitochondrial DNA (mtDNA) polymorphisms are involved in a case report of a patient with mesial temporal lobe epilepsy-hippocampal sclerosis (MTLE-HS). DESIGN We report the whole genome mtDNA deep sequencing results and clinical features of a 36-year-old woman with MTLE-HS. We used pyrosequencing technology to sequence a whole mitochondrial genome isolated from six different regions of her brain and blood. To assess the possible role of mitochondrial DNA variations in affected tissues, we compared all specimens from different regions of the hippocampus and blood. RESULTS In total, 35 homoplasmic and 18 heteroplasmic variations have been detected in 6 different regions of the hippocampus and in blood samples. While the samples did not display any difference in homoplasmic variations, it has been shown that hippocampus regions contain more heteroplasmic variations than blood. The number of heteroplasmic variations was highest in the CA2 region of the brain and accumulated in ND2, ND4 and ND5 genes. Also, dentate and subiculum regions of the hippocampus had similar heteroplasmic variation profiles. DISCUSSION We present a new rare example of parallel mutation at 16223 position. Our case suggests that defects in mitochondrial function might be underlying the pathogenesis of seizures in temporal lobe epilepsy.