Flow diverter stent treatment for unruptured supraclinoid segment internal carotid artery aneurysms: a Turkish multicenter study.

OBJECTIVE: Despite the relatively high success of surgical clipping of supraclinoid segment aneurysms of the internal carotid artery (ICA), flow diverter (FD) stent therapy is becoming increasingly used for these aneurysms. This study aims to evaluate the characteristics of FD placement for unruptured ICA supraclinoid segment aneurysms at 6 different centers with different experience levels in Türkiye. METHODS: In this retrospective, multicenter study, the authors reviewed the demographic information, aneurysm shape/dimensions (neck, aspect ratio, dome/neck ratio, and maximum diameter), preoperative antiplatelet regimen, FD stent brand, perioperative complications, intervention time, clinical (modified Rankin Scale) and radiological (O'Kelly-Marotta [OKM] grading scale) outcomes, and follow-up time of 54 patients. RESULTS: A total of 55 interventions for 61 aneurysms (58 supraclinoid ICA aneurysms) were performed in the 54 patients included in the study. The female/male ratio in this population was 44/10, and the mean age was 53.5 ± 13.6 (range 21-82) years. The most common form and location of the aneurysms were saccular 91.4% (53/58) and ophthalmic segment 69% (40/58), respectively. The preferred antiplatelet regimen was acetylsalicylic acid plus ticagrelor 50% (27/54). The overall complication rate was 25.5% (14/55), and the mean follow-up time was 25.76 ± 17.88 months. The successful radiological outcome (OKM grade C or D) rate at the 6-month follow-up was 92.6%. No perioperative complications led to any permanent or transient neurological deficit. CONCLUSIONS: The results of this first multicenter study evaluating FD stent use for unruptured ICA supraclinoid segment aneurysms showed that FD stent treatment is a feasible method for replacing clipping and coil embolization with manageable complications and a high success rate.

Tentorial Venous Sinuses: A Cadaveric Study.

AIM: To present the configuration of the tentorial venous sinuses, and to determine the optimal incision zone on the tentorium cerebelli. MATERIAL AND METHODS: This study has been completed with 24 autopsied cadavers. For every cadaver, firstly, supratentorial tissues were removed and tentorial measurements were noted, superior part of the tentorial sinuses was captured, and then infratentorial tissues were removed, and all the sinuses were checked and captured. RESULTS: Average age of the studied 24 fresh cadavers was 50 years, wherein 4 were females and 20 were males. Tentorial sinus was presented in 87% of the cases, with 45% medial, 33% lateral, and 22% in the middle third of each tentorium half. CONCLUSION: This study showed the pattern, incidence, location, and distribution of tentorial venous sinuses and tried to find the optimum incision zone by identifying sparse areas for the venous sinuses during transtentorial surgical approaches.

A Novel Perspective to Gamma-Knife Radiosurgery for Solitary Meningiomas: Adaptability of Fast Imaging Employing Steady-State Acquisition/Constructive Interference in Steady-State Magnetic Resonance Imaging.

AIM: T1-weighted contrast-enhanced (T1+C) magnetic resonance imaging (MRI) sequences are usually used for planning meningioma treatment via Gamma-Knife radiosurgery (GKRS). However, practitioners should refrain from using contrast agents because of allergies or other systemic diseases. The fast imaging employing steady-state acquisition (FIESTA) sequence is a high-resolution T2-weighted MRI sequence with a high signal-to-noise ratio that provides good image contrast without using any contrast agent. However, in T1+C sequences, the tumor size appears more prominent due to the contrast agent effect, especially in meningiomas with sinus invasion. Thus, normal anatomical structures may be exposed to radiation. Therefore, we aimed to compare T1+C with FIESTA MRI sequences to protect healthy brain tissue during meningioma treatment with GKRS. MATERIAL AND METHODS: After reviewing the data of 54 patients with solitary meningioma who underwent GKRS between January 2020 and June 2022, demographic characteristics were noted, tumor volumes on T1+C and FIESTA MRI sequences were measured, and sequences were compared. The patients were then divided into two groups according to the presence of invasion to intracranial venous sinuses (groups 1 and 2, respectively). SPSS 11.5 software was used for data analysis, with the level of significance set at 0.05. RESULTS: While no significant age and tumor size differences were observed between groups 1 and 2, sinus invasion was significantly higher among males. Tumor volumes measured in both groups were significantly smaller on FIESTA sequences than on T1+C sequences. CONCLUSION: The T1+C sequence has been the primary imaging method because of meningiomas\' high contrast enhancement feature. However, the T1+C sequence during GKRS planning is an effective imaging method in treating meningiomas; FIESTA sequences can more precisely delineate the tumor border. In this study, we consider that using the FIESTA/CISS sequence MRI for planning meningioma therapy with Gamma-Knife can reduce target volume and prevent irradiation of healthy brain tissue.

The effectiveness of gamma knife radiosurgery for the management of residual high-grade gliomas: A single institutional study.

High-grade gliomas (HGGs) are presently managed via surgical resection, external beam radiation therapy (EBRT), and chemotherapy. Although Gamma Knife radiosurgery (GKRS) is currently used to manage HGGs, it has not been considered standard care. This paper aims to compare the contribution of GKRS to clinical outcomes in patients in which gross total resection (GTR) cannot be achieved. We retrospectively reviewed the data of 99 patients with HGG (World Health Organization (WHO) grade III and IV) from two groups: group 1 consisted of 68 patients for which only EBRT was administered, and group 2 consisted of 31 patients for which EBRT and GKRS were administered. Patient demographic data, the extent of resection, IDH mutation, radiation dosage, progression-free survival (PFS), overall survival (OS), and follow-up time were recorded and compared across groups. The grade III/IV tumor ratio was 10/58 and 10/21 in groups 1 and 2, respectively. In group 2, PFS and OS were higher than in group 1 (P = 0.030 and 0.021). The mean follow-up time was 15.02 ± 11.8 (3-52) and 18.9 ± 98.6 (7-43) months in groups 1 and 2, respectively. In addition to the standard management of HGGs in patients without GTR, boost GKRS during the early postoperative period is beneficial for increasing PFS and OS.

The Supracerebellar Transtentorial Approach in the Prone Position.

The mediobasal temporal region (MTR) is a deep part of the brain covered by eloquent structures. In certain cases, accessing this region is challenging. According to the literature, the supracerebellar transtentorial (SCTT) approach provides safe access to the MTR. Since this approach was introduced by Voigt and Yasargil, many researchers used SCTT in different positions. In particular, the sitting position was the most preferred as it allows the cerebellum to fall away from the tentorium. However, this position has disadvantages such as venous air embolism (VAE), paradoxical air embolism (PAE), and some non ergonomic conditions during surgery. We report two cases with tumors affecting the middle and posterior medial temporal regions. Both patients underwent surgeries in the prone position using the SCTT approach. There were no procedure-related complications. Histopathological results were as follows: psammomatous meningioma in the first case; adenocarcinoma metastasis in the second case. Thus, in this study, the efficacy, feasibility, and safety of accessing the MTR using the SCTT approach in the prone position were demonstrated.

The importance of IDH1, ATRX and WT-1 mutations in glioblastoma.

Numerous genetic pathways associated with glioblastoma development have been identified. In this study, we investigated the prognostic significance of IDH1 and ATRX mutations and WT-1 and p53 expression in glioblastomas and that of surgical methods, radiotherapy and chemotherapy. 83 patients with glioblastomas were retrospectively evaluated. Immunohistochemical analysis was performed for IDH1, ATRX and WT-1 expression. Tumour cells were positive for IDH1 in 9.6% of the patients. In 4.8% of the patients, loss of ATRX expression was observed in tumour cells; 86.7% of the patients were WT-1 positive, and 12.05% of the patients were p53 positive. No statistically significant difference was found in the progression-free and overall survival according to IDH1, ATRX, WT-1 and p53 expression. There was a statistically significant difference in the progression-free and overall survival according to the radiotherapy status. There was a statistically significant difference in the overall survival according to the chemotherapy status. There was no statistically significant difference in the progression-free and overall survival according to the surgical method. IDH1 and ATRX mutations, p53 overexpression and WT-1 expression alone did not have a significant effect on the prognosis of patients with glioblastoma; however, radiotherapy and chemotherapy had a positive effect on survival.

Comparison of Subthalamic Nucleus vs. Globus Pallidus Interna Deep Brain Stimulation in Terms of Gait and Balance; A Two Year Follow-Up Study.

AIM: To compare the effects of subthalamic nucleus (STN) and globus pallidus interna (GPi) deep brain stimulation (DBS) on the motor outcome, gait and balance function, fall risk (FR), and non-motor symptoms in patients with advanced Parkinson's disease (PD). MATERIAL AND METHODS: We randomized patients with advanced PD with the indication of DBS to undergo either STN or GPi DBS and followed them for 2 years. We collected data at baseline and postoperative 6, 12, and 24 months. We compared changes in the Unified Parkinson's Disease Rating Scale (UPDRS) score, timed gait tests, posturography, non-motor symptom questionnaire (NMSQuest), hospital anxiety and depression (HAD) scale, and levodopa equivalent dose (LED). RESULTS: We enrolled and randomized 12 patients to receive either STN (n = 6) or GPi (n = 6) DBS. Postoperative motor outcomes were significantly improved in both groups (p < 0.05). In both groups, timed gait tests exhibited better performance in mobility; however, patients receiving GPi DBS performed better than those receiving STN DBS in the timed gait tests (p < 0.05). Furthermore, the posturographic evaluation demonstrated a significant elevation in the FR in the STN group (p < 0.05). CONCLUSION: Both STN and GPi DBS are equally effective in alleviating disabling motor complications. However, seemingly, STN DBS could cause more gait and balance problems; hence, a tailored approach seems to be more appropriate in the target selection.

Effect of Subthalamic Nucleus Stimulation on Pedunculopontine Nucleus Neural Activity.

BACKGROUND: The pedunculopontine nucleus has recently been proposed as an alternative target for deep brain stimulation for the treatment of medically intractable Parkinson's disease. The suggested indication for pedunculopontine nucleus deep brain stimulation is severe and medically intractable axial symptoms such as gait and postural impairment. OBJECTIVE: Our goal in this study was to describe the effects of subthalamic nucleus stimulation on pedunculopontine nucleus electrophysiological activity. METHODS: Fourteen male Wistar rats were divided into a sham stimulation group and an experimental group. In both groups, electrodes were implanted bilaterally into the subthalamic nucleus and into the right pedunculopontine nucleus. Microelectrode recordings were carried out in both groups prior to and during subthalamic nucleus stimulation. RESULTS: Subthalamic nucleus stimulation produced no clear inhibition of neuronal firing in the pedunculopontine nucleus. However, we found that stimulation of the subthalamic nucleus at 60 Hz produces some entrainment of pedunculopontine nucleus neuronal firing and a shift of subthalamic nucleus firing patterns to more tonic and random patterns. These results are consistent with the effects of deep brain stimulation on neuronal activity in the subthalamic nucleus and globus pallidus internus. CONCLUSION: The result of this study provides additional evidence to improve our understanding of the mechanism of subthalamic nucleus-deep brain stimulation, and its physiological consequences.

Increased Expression of Matrix Metalloproteinase-9 in Patients with Temporal Lobe Epilepsy.

AIM: The molecular mechanism of epileptogenesis in temporal lobe epilepsy is still unclear. Experimental studies have suggested that matrix metalloproteinases have important roles in this process, but human studies are limited. The aim of this study was to assess the expression of MMP-9, MMP-2 and their tissue inhibitors (TIMP-1 and TIMP-2) in patients with temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). MATERIAL AND METHODS: The tissue samples from temporal neocortex and hippocampus were obtained from patients with temporal lobe epilepsy with hippocampal sclerosis who had undergone anterior temporal lobectomy for recurrent medically resistant seizures. Immunohistochemical methods were used to determine the expression of MMP-9, MMP-2 and their tissue inhibitors. Tissue samples were also analyzed with transmission electron microscopy. RESULTS: The immunoreactivity for MMP-9 both in hippocampal and temporal neocortical neurons was stronger than that of MMP-2. Additionally, there was a mild reaction for its tissue inhibitor TIMP-1 as with TIMP-2. The TEM analysis of the hippocampus revealed that there was apparent ultra-structural damage on the pericarya and neuropil of some neurons. There was obvious damage in the mitochondria and the nuclear membrane. CONCLUSION: The preliminary results of this study revealed that MMP-9 may have a role in patients with drug resistant TLE-HS.

Spontaneous recovery of post-traumatic cerebrospinal fluid rhinorrhea following meningitis: A case report.

The aim of the present report was to present the patient with an anterior cranial base fracture who developed post-traumatic cerebrospinal fluid rhinorrhea, which recovered after onset of meningitis complication. A 26-year-old male patient who had a traffic accident one week ago was sent to our clinic because of his rhinorrhea persisting for 4 days. On cranial computed tomography, fracture of the left frontal skull base and sinus walls, a fracture line on temporal bone, parenchymal bleeding in the vicinity of the frontal sinus, subarachnoidal bleeding and left temporal extradural hematoma were detected. Then he underwent sinus wall repair and extradural hematoma was drained through bifrontal craniotomy. However, rhinorrhea persisted which resulted a deterioration in consciousness and he entered into a deep somnolent state. When his symptoms of meningitis became apparent, rhinorrhea of the patient disappeared. The patient transferred in intensive care unit and re-connected to a lumbar drainage system. On cerebral magnetic resonance imaging, regression of contrast-enhanced lesions localized in the left anterotemporal and frontal and in the regions lateral to the right trigon and medial to the right thalamus and in the right posteroparietal regions was observed. Despite repair of the anterior cranial fracture and lumbar drainage, rhinorrhea may persist. Herein, development of meningitis caused disappearing of rhinorrhea symptoms without any need for surgical intervention.

The effects of brain stimulation of subthalamic nucleus surgery on gait and balance performance in Parkinson disease. A pilot study.

INTRODUCTION: Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by tremor, rigidity and bradykinesia. Gait and postural difficulties supersede tremor, rigidity and bradykinesia as drivers of disease burden in patients with advanced PD. The aim of this study was to describe the effects of deep brain stimulation of the subthalamic nucleus on gait ability and balance performance in patients with PD. MATERIAL AND METHODS: We studied 19 consecutive patients who underwent bilateral stimulation of the subthalamic nucleus. Patients were evaluated preoperatively and at the 5(th) day and 6(th) month after surgery. Timed Up and Go Test, 12 m Walking Test, Chair Stand Test and Berg Balance Scale (BBS) were used to assess mobility and balance performance. Unified Parkinson's Disease Rating Scale (UPDRS III) and Hoehn and Yahr Scale were also used. RESULTS: All the patients' mobility ability and balance performance improved after surgery (p < 0.05). At the 6th month after surgery, the Timed Up and Go Test scores were decreased from 56.05 ±42.52 to 21.47 ±20.36, the 12 m Walking Test scores were decreased from 100.44 ±66.44 to 28.84 ±19.79, the Chair Stand Test scores were increased from 4.00 ±4.66 to 11.68 ±4.43 and the BBS score was increased from 12.84 ±6.89 to 38.89 ±8.79. UPDRS total scores were significantly improved 6 months after surgery (p < 0.001). UPDRS total scores were decreased from 98.26 ±37.69 to 39.36 ±18.85. The Hoehn and Yahr Scale score was significantly decreased after surgery (p < 0.05). CONCLUSIONS: Surgical therapy is an effective treatment to improve gait ability and balance performance in Parkinson's patients.

Reuse of internal pulse generator in cases of infection after deep brain stimulation surgery.

BACKGROUND: Hardware-related infection after deep brain stimulation (DBS) is one of the most serious complications and may need additional interventions. OBJECTIVES: To reuse the internal pulse generator (IPG) after DBS infection and to reduce the economic costs. METHODS: A database of 102 patients who underwent DBS surgery was used in the study. The incidence, clinical characteristics and management of infections while reusing the IPG after DBS-related infection were analyzed and reported. RESULTS: The overall infection rate was 5.9% (6 of 102 patients). Management consisted of total hardware removal followed by intravenous antibiotics. The IPG was at first kept in a solution, then rinsed with water and dried following sterilization with ethylene oxide gas at 38 °C for 18 h. When the treatment of the infection was finished, we reused the IPG and reimplanted the DBS. No hardware-related infection or other complications were observed after reimplantation. CONCLUSIONS: Management of hardware-related infections can be challenging. The medical and economic costs associated with these infections are enormous. The IPG can often be saved in infected patients. Thus, a significant cost burden is eliminated. Properly executed, reuse of IPG should markedly reduce the costs of these devices.

Manic episode following deep brain stimulation of the subthalamic nucleus for Parkinson's disease: a case report.

AIM: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an established therapy for patients with Parkinson's disease (PD) associated with motor complications of long term L-dopa treatment. MATERIAL AND METHODS: Here we report two cases with DBS- induced manic episode, focusing on the functional and anatomic correlates of psychiatric adverse effects of STN stimulation. RESULTS: We present two cases of PD with motor complications due to long term L-dopa treatment that developed their first episodes of mania with psychotic symptoms after bilateral STN-DBS implantation. DBS-induced psychiatric adverse effects may be attributable either to limbic connections and STN-specific oscillations or stimulation of the medial forebrain bundle.

Management of medically intractable genitofemoral and ilioingunal neuralgia.

AIM: To evaluate the effectiveness of invasive procedures in medically intractable genitofemoral and ilioingunal neuralgia. MATERIAL AND METHODS: This is a prospective study of 20 patients with genitofemoral and ilioinguinal neuralgias who were treated at our medical center between 2007 and 2011. Genitofemoral and ilioinguinal nerve blocks were performed in all cases after medical treatment had failed to alleviate the patients' pain. Neurectomy was performed for the patients whose pain did not improve. Patient histories, physical examinations and visual analogue scale scores before and after treatments were analyzed. RESULTS: Fourteen (70%) of the patients were treated with nerve blocks and six (30%) of the patients whose pain did not improve with nerve block application underwent neurectomy which resulted in pain relief. CONCLUSION: For patients with medically intractable genitofemoral and ilioinguinal neuralgias, nerve blocks and neurectomies can be applied safely for pain control.

The history of neurosurgery in Anatolia and Turkey: the Turkish Neurosurgical Society.

Although the history of neurosurgery in Anatolia goes back ten thousand years, modern surgery began in Turkey in 1890. Neurosurgery in Turkey began in the first half of the 20th century. However, general surgeons began applying neurosurgical techniques back in the late 19th century. Most of these applications included procedures for craniocerebral traumas and infections. Dr. Cemil Topuzlu (1868-1958) is the founder of modern surgery in Turkey. Dr. Abdulkadir Cahit Tuner became the first neurosurgeon with a degree in Turkey in 1923. The first neurosurgery department was established in Istanbul in 1923, and the first training program began in the late 1940s. Currently there are almost 1200 neurosurgeons in Turkey and 75 training clinics at university hospitals and Training and Research Hospitals of the Ministry of Health provide neurosurgery training. The current state of neurosurgery in Turkey is parallel to that of the advanced Western countries. Apart from the application of neurosurgical procedures, there have been many scientific studies from Turkish neurosurgeons contributing to the total body of literature in neurosurgery.

A case report of surgically treated drug resistant epilepsy associated with subependymal nodular heterotopia.

Subependymal nodular heterotopia (SNH) is a cortical development malformation that is commonly associated with medically resistant epilepsy. Cases of SNH are challenging to treat surgically because there are typically multiple nodules, which may be involved in epileptogenesis. Moreover, dual pathology may exist in these patients. Here, we present a case with unilateral subependymal heterotopic nodules associated with ipsilateral hippocampal atrophy. Invasive and non-invasive work-ups revealed that the hippocampus was the actual ictal onset zone and that the SNH was not involved. An anterior temporal lobectomy was carried out, and postoperative seizure outcome was class Ia at the end of 2 years. The case demonstrates that SNH may not play a major role in patients with dual pathology. However, direct electroencephalography (EEG) recording from areas of SNH and other possible epileptogenic regions is indispensable in defining the ictal onset zone and avoiding poor surgical outcomes.

The effects of clenbuterol on cerebral vasospasm in an experimental rat model of subarachnoid hemorrhage.

OBJECTIVE: To investigate the possible therapeutic effects of clenbuterol on cerebral vasospasm after subarachnoid hemorrhage (SAH) in rats. METHODS: Eighteen male albino Wistar rats, each weighing 200-250 g, were randomized into three groups; Group 1 (Control group) (n = 6) having no SAH and no treatment; Group 2 (Sham group) (n = 6) having only SAH and Group 3 (Experimental group) (n = 6) having SAH treated with clenbuterol. Group 2 has been accepted as sham group to the experimental group. Experimental SAH was induced using a modified rat double hemorrhage model. Clenbuterol was administered twice daily in 12-hour intervals for three days at a dose of 0,1 mg/kg/day. The luminal diameter of the basilar artery was measured on each section with an optic micrometer by an experienced pathologist blinded to the groups. RESULTS: Mean basilar artery diameters were found to be different between the three groups (p < 0.001). Mean value of Group 2 was significantly lower than that of Group 1 (p < 0.001). While mean value of Group 3 was significantly greater than that of Group 2 (p = 0.001), Groups1 and 3 were found to be similar (p = 0242). CONCLUSION: Clenbuterol has favorable effects in the treatment of rat cerebral vasospasm (CVS). Further investigations are needed to evaluate both molecular effects and to find out effective treatment dose of clenbuterol on CVS.

The influence of subthalamic nucleus deep brain stimulation on physical, emotional, cognitive functions and daily living activities in patients with Parkinson's disease.

AIM: To describe effectiveness of deep brain stimulation of subthalamic nucleus (DBS STN) on physical, emotional, cognitive functions and daily activities in Parkinson's patients. MATERIAL AND METHODS: Ten patients (51.20 ±10.20 yr.) were assessed three times. The Time Up and Go Test, 12 m Walking Test and Chair Stand Test were used to assess mobility and balance. Purdeu Pegboard and hand writing tests were used to evaluate hand function. The Hospital Anxiety and Depression Scale (HAD) was used to detect depressive symptoms and anxiety score. The Unified Parkinson\'s Disease Rating Scale (UPDRS) and Hoehn &Yahr Scale were also used. The Schwab and England Test was used to evaluate the daily activities (ADL). RESULTS: The results showed that all the patients' mobility and balance ability improved after surgery (p < 0.05). Depressive symptoms / anxiety scores were found to be lower than before surgery (p < 0.05). There were differences in terms of ADL and UPDRS scores after surgery (p < 0.05). At six month after surgery; depressive symptoms decreased by 78%. ADL and UPDRS motor and total scores improved by 190%, 72%, and 78% respectively. CONCLUSION: STN DBS is an effective treatment to improve physical functioning, emotional status and daily activities in Parkinson's patients. However, it did not show any positive effect on cognitive function.

Deep brain stimulation of the pedunculopontine nucleus in a patient with freezing of gait.

CASE PRESENTATION: A 54-year-old male patient presenting probable multiple system atrophy with predominant parkinsonism who underwent bilateral deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) is presented. The patient had dominant freezing of gait (FOG), levodopa-resistant bradykinesia, and autonomic disturbances, but with a good cognitive condition. METHODS: The patient underwent bilateral DBS of the PPN, which ended with modest benefits. RESULTS AND CONCLUSION: Although he had a short postoperative follow-up (6 months), his neurological status remained stable and PPN DBS provided modest improvements in the gait disorder and freezing episodes. This unusual case suggests that the mesencephalic pedunculopontine region may have a role in locomotor symptoms and the potential to provide a limited improvement in FOG.

Effects of the hippocampal deep brain stimulation on cortical epileptic discharges in penicillin - induced epilepsy model in rats.

AIM: Experimental and clinical studies have revealed that hippocampal DBS can control epileptic activity, but the mechanism of action is obscure and optimal stimulation parameters are not clearly defined. The aim was to evaluate the effects of high frequency hippocampal stimulation on cortical epileptic activity in penicillin-induced epilepsy model. MATERIAL AND METHODS: Twenty-five Sprague-Dawley rats were implanted DBS electrodes. In group-1 (n=10) hippocampal DBS was off and in the group-2 (n=10) hippocampal DBS was on (185 Hz, 0.5V, 1V, 2V, and 5V for 60 sec) following penicillin G injection intracortically. In the control group hippocampal DBS was on following 8 µl saline injection intracortically. EEG recordings were obtained before and 15 minutes following penicillin-G injection, and at 10th minutes following each stimulus for analysis in terms of frequency, amplitude, and power spectrum. RESULTS: High frequency hippocampal DBS suppressed the acute penicillin-induced cortical epileptic activity independent from stimulus intensity. In the control group, hippocampal stimulation alone lead only to diffuse slowing of cerebral bioelectrical activity at 5V stimulation. CONCLUSION: Our results revealed that continuous high frequency stimulation of the hippocampus suppressed acute cortical epileptic activity effectively without causing secondary epileptic discharges. These results are important in terms of defining the optimal parameters of hippocampal DBS in patients with epilepsy.