The benefits of modern treatments for epilepsy have long been excluded from Japan. However, after a long drug approval period, the following 4 new antiepileptic drugs (AEDs) have recently become available in Japan : gabapentin in 2006, topiramate in 2007, lamotrigine in 2008, and levetiracetam in 2010. Some newer AEDs have similar efficacy and improved tolerance compared to older AEDs. However, not all epilepsy patients can receive the direct benefits of the newer AEDs, because the care of patients with both newly-diagnosed and intractable epilepsy is not only the responsibility of neurologists with expertise in epilepsy, but also of general neurologists, pediatricians, psychiatrists, and neurosurgeons in Japan.
  This article addresses the current issues in the diagnosis and management of epilepsy, and emphasizes the importance of newer AEDs, especially for general neurosurgeons in Japan.

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  The defining characteristics of patients for whom craniotomy is the recommended treatment for their refractory seizures have been clarified during the last two decades. Seizure outcome of resection surgery for focal seizures associated with focal lesions is satisfactory. Particularly for mesial temporal lobe epilepsy, surgical treatment should be considered from the earlier stage of the disease. Meanwhile, surgical outcomes in extratemporal lobe epilepsy and nonlesional epilepsy still have room for improvement using various approaches. Although not curative, palliative procedures and neuromodulation therapies are available for these ‘truly intractable epilepsy cases’ at present.

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  Patients with neuropathic pain (NP) have proved challenging to manage prior to the establishment of guidelines for the pharmacological treatment of NP. Recent guidelines including those for the pharmacologic management of NP issued by Japan Society of Pain Clinicians provide evidence-based medication recommendations concerning first-line treatments for NP including tricyclic antidepressants and calcium channel α2-δ ligands. Other medications would be employed as second-or third-line treatments. Spinal cord stimulation (SCS) is also an accepted method of control for chronic NP which has been used for many years and is supported by a substantial evidence base. SCS guidelines for the management of pain were recently published by the British Pain Society. The recommendations refer to the current body of evidence relating to SCS. The present review serves to provide an overview of the key principles for the treatment of NP including pharmacological therapies and SCS.

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  Deep brain stimulation (DBS) has been used as a therapy for treating intractable pain since the 1960s. After the discovery of multiple cortico-striato-thalamo-cortical (CSTC) loops and that the malfunction of these loops occurs in Parkinson disease (PD) in 1980s, DBS has also been re-recognized as a treatment of central nervous system (CNS) loop circuit disease. Presently, DBS is widely used not only for treating PD or essential tremor, but also for other involuntary movement diseases, such as dystonia or ballism.
  We have treated 138 patients with subthalamic nucleus (STN) -DBS for PD from 1998, and 26 of these STN-DBS cases have been followed up for more than 5 years. From the observation of these cases we noticed that STN-DBS is effective for treating the so-called dopa-related motor symptoms of PD, such as tremor and rigidity, but it is less effective for the so-called dopa-non-related motor symptoms of PD, such as gait and postural disturbance, speech or swallowing. Also, it is not effective for treating the non-motor symptoms of PD, such as psychiatric, cognitive or autonomic symptoms.
  In our literature review, we found that the therapeutic efficacy and safety of two targets, the STN and globus pallidus pars interna (GPi) for PD have been continuously compared. Also an “early stim study” was published in which the therapeutic effect of STN-DBS was compared to that of the best medication in rather early stage of PD patients.
  We successfully targeted the posterior subthalamic area (PSA) DBS for strong tremor patients and had success with Vo stimulation for a hereditary ballism patient ; two examples of the expanding surgical indications for DBS.

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  Deep brain stimulation (DBS) is a safe and effective treatment for medically refractory movement disorders such as Parkinson's disease, essential tremor and dystonia. The success of DBS in treating movement disorders with over 100,000 patient implants has revived interest in the use of DBS for the neurosurgical management of refractory conditions including epilepsy, psychiatric disorders (obsessive compulsive disorder, major depressive disorder, addictions, and eating disorders), neuropathic chronic pain, headaches, cognitive disorders, and traumatic brain injury. This manuscript provides a review of the current application of DBS surgery in movement disorders, psychiatric and other conditions.
  Additionally, an overview of the recent advances in our understanding of the neural circuitry underpinning the pathophysiology of these disorders is provided. The use of imaging and the latest surgical techniques to target these structures will be highlighted. Furthermore, new technology such as the introduction of the “closed loop system”, smart DBS devices, responsive brain stimulation and emerging neuromodulation approaches will be discussed.

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  Predicting cerebral aneurysm rupture is still difficult since we do not have enough information about the risk factors for the aneurysm rupture. We studied the hemodynamic related factors for the development, enlargement, and rupture of cerebral aneurysms, using both an animal model of experimentally induced cerebral aneurysms and a computational fluid dynamics (CFD) simulation of human cerebral aneurysms. We introduce here our evidence suggesting that cerebral aneurysms develop near the apex of arterial bifurcations as a result of an increase in hemodynamic factors, particularly in wall shear stress.
  Aneurysms in our animal model developed at several sites along the circle of Willis, where blood flow is increased in compensation for unilateral common carotid artery ligation and experimental hypertension, suggesting that the enhanced hemodynamic stress is of primary importance. Our hemorheological studies in rats showed that the wall shear stress was increased and at its highest level at the distal end of the aneurysm orifice. Vascular endothelial cells can sense fluid shear stress caused by blood flow, change their shape and release several substances in response to the shear, and in turn regulate blood flow. During aneurysm formation, vascular endothelial cells may sense excessively high levels of wall shear stress over the physiological limit, which may initiate damage to vascular wall components, leading to aneurysm formation. In order to clarify the role of endothelial shear sensing on aneurysm formation, we examined the effect of blockage in the P2X4 purinoceptor, one of the vascular endothelial shear-sensors, on the frequency of aneurysm induction after aneurysm-inducing surgery. In a group of P2X4 purinoceptor knockout mice, the number of induced aneurysms was significantly smaller than that in the control wild-type mice group.
  The CFD analyses using 3-dimentional CT angiographic images of human cerebral aneurysms also indicated the tendency whereby the magnitude of wall shear stress at the aneurysm orifice is high only if the measured flow velocities derived from physiological data of individual patients were used as inlet boundary conditions. The data are consistent with the results found using an animal model. In order to examine more details of hemodynamics in human aneurysms and to clarify hemodynamic risk factors for enlargement and rupture of cerebral aneurysms with CFD techniques, we just started a multi-institutional prospective clinical study, named “Computational Fluid Dynamics Analysis of Blood Flow in Cerebral Aneurysms : Prospective Observational Study (CFD ABO Study) ” .

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  We report two cases of dural arteriovenous fistula (dAVF) that developed after surgery at sites that were remote from the craniotomy location. Case 1 : A 41-year-old obese woman underwent clipping for a ruptured anterior communicating artery aneurysm, using an interhemispheric approach. Twenty days after the surgery, she developed dAVFs in the bilateral convexity, which were fed by the middle meningeal arteries, and drained into the middle meningeal veins. The dAVFs disappeared spontaneously after 1 year of observation. Case 2 : A 69-year-old woman underwent clipping for an unruptured left internal carotid-posterior communicating artery aneurysm, using left pterional approach under exposure of the cervical internal carotid artery. Preoperative cerebral angiography demonstrated the presence of a left sigmoid sinus stenosis. Eight months after the surgery, she experienced pulsatile tinnitus, and a dAVF in the left transverse-sigmoid sinus was confirmed by cerebral angiography. A near complete obliteration of the dAVF was achieved by transarterial and transvenous embolization. We speculate that venous hypertension, due to obesity in case 1 and due to pre-existing sigmoid sinus stenosis and manipulation of the cervical internal carotid artery in case 2, caused the development of the dAVFs.

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  Transient bradycardia, hypotension, and asystole arise from activation of the trigemino-vagal reflex by direct stimulation of the trigeminal nerve or branches in the dura mater or cerebellar tentorium. We report two cases of transient asystole during surgery by activation of the trigemino-vagal reflex. In one case, a 63-year-old woman with an unruptured internal carotid artery aneurysm at the origin of the anterior choroidal artery underwent craniotomy. When a clip applied for neck clipping touched the dura mater, transient asystole occurred twice, lasting 4-5 seconds each. After immediate cessation of surgical manipulation, heart contractions recovered spontaneously. The trigemino-vagal reflex may occur in any open craniotomy surgery, and is not rare in clipping operations for supratentorial unruptured aneurysm. However, this reflex recovered without any postoperative complications following prompt cessation of surgical manipulations.

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