Epilepsy affects 5-8 out of every 1,000 people and can occur at any age. Abnormal neuronal activity leads to recurrent seizures. While antiseizure medications control seizures in many patients, some cases are refractory, necessitating surgical intervention.

  Temporal lobe epilepsy (TLE) is categorized into two types : lateral temporal lobe epilepsy, where seizures originate from the lateral temporal cortex, and mesial temporal lobe epilepsy, where seizures originate from the hippocampus or amygdala. Mesial TLE (MTLE) is a unique form of epilepsy and has well-documented efficacy of surgical treatment for refractory cases.

  Neurosurgeons frequently manage patients with this syndrome, yet many remain unaware of their condition or continue treatment with drugs alone despite experiencing intractable seizures. This article aimed to provide the essential knowledge for neurosurgeons to effectively diagnose and treat MTLE.

  It has been 10 years since awake surgery was first covered by government insurance in Japan. Originally, the focus of awake surgery was to preserve movement, sensation, and language functions, and it has now expanded to preserve the visual field and higher cognitive functions. However, monitoring of higher cognitive functions needs to be improved. Higher cognitive functions cooperate in a complex manner. Appropriate task development is required for a single intraoperative task to monitor a single type of higher cognitive function. Furthermore, functional recovery due to brain plasticity is frequently observed, especially for higher cognitive functions. Removal of brain areas that show a positive response during awake monitoring does not necessarily result in permanent functional impairment. Advances in neuroscience regarding brain functional networks and brain plasticity can have a great impact on the concept of awake surgery, and we believe that neurosurgeons play a major role in it.

  Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by dopamine deficiency in the substantia nigra of the midbrain and resultant motor symptoms such as akinesia, rigidity, and tremor. As the disease progresses, motor complications including the wearing-off phenomenon and dyskinesia appear. This stage is referred to as the advanced stage. Surgical treatment and device therapy are options for treating advanced PD refractory to medication treatment. Deep brain stimulation (DBS) is a well-established treatment strategy that improves motor symptoms and quality of life for patients with advanced PD. DBS devices have undergone upgrades, expanding therapeutic options available. These include directional lead systems with fine control settings, stimulus generators with independent constant current settings, sensing technology to record local field potentials (LFP) through DBS electrodes in the target brain region, and adaptive DBS with automatic stimulation adjustment based on LFP. Device therapies for continuous drug delivery are also advancing. Levodopa-carbidopa intestinal gel therapy can improve motor symptoms but requires the patient to undergo a gastrostomy. New options such as continuous subcutaneous injections of foslevodopa and foscarbidopa have been approved, allowing for easier use of device therapy. Each therapy has its own advantages and disadvantages and is recommended based on a patient's specific clinical profile. Therefore, the most appropriate therapy should be selected after evaluating clinical profiles.

  Spasticity is a condition of increased muscle tone due to abnormal reflexes caused by damage to the upper motor neurons. Moreover, it is one of the most frequently encountered symptoms in neurosurgical practice as a chronic sequela of severe head injury or stroke. Spasticity not only interferes with motor function but also causes pain due to muscle stiffness and/or spasms ; therefore, appropriate treatment can improve the quality of life of patients and caregivers. Treatment options include medical therapies, such as oral medications and botulinum toxin, and surgical therapies, such as selective peripheral neurotomy and intrathecal baclofen. These medications are suitable for initial treatment as they are reversible and relatively safe. Although selective peripheral neurotomy effectively controls local spastic symptoms, the surgical indications should be carefully discussed since the surgical technique involves partial lesioning of the nerve, which can result in irreversible changes. Intrathecal baclofen has the advantage of medication dosage adjustability ; however, it requires surgery to install a pump and is associated with risks such as equipment-related complications. Since the intensity and location of spasticity symptoms vary greatly among patients, it is necessary to tailor these treatment options based on the specific treatment goals established for each patient. Therefore, practitioners should understand the advantages and disadvantages of each treatment option.

  Glue migration is a potential complication of endovascular surgery performed using n-butyl-cyanoacrylate (NBCA). Herein, we report the management of four cases with NBCA glue migration encountered at our institution. NBCA glue migration involved tumor embolization in three cases : glue migration was observed at the internal carotid artery in two cases and anterior cerebral artery in one case. The migrated glues were successfully retrieved in these cases using stent retrievers (SRs). The remaining case involved glue migration during arteriovenous malformation embolization. The glue migrated into the vertebral and posterior cerebral arteries. In this case, a stent was deployed at each site after administrating antiplatelet therapy. Our findings suggest that NBCA embolectomy using a SR is useful for managing glue migration. Furthermore, in cases where the NBCA glue needs to be compressed against the vessel wall, antiplatelet therapy followed by stenting can be used, depending on the subsequent treatment plan.

  Exoscope technology shows significant promise in cerebrovascular surgery, particularly owing to its advanced image-editing capabilities. We have employed exoscope as the primary visualization tool in various cerebrovascular procedures. A total of 32 treatments were performed, including cerebral aneurysm clipping, carotid endarterectomy, and intracerebral hematoma removal. In this study, we compared the effectiveness of the exoscope with that of traditional light microscope across these procedures. Our findings suggest that the exoscope is comparable to the light microscope in terms of straight visual alignment for field during dissection and clipping procedures. Notably, exoscopy demonstrated superior performance in carotid endarterectomy.