Japan is one of the world’s most rapidly aging and long-lived societies. As a result, by 2025, around 7.3 million people in Japan will have dementia up from around 4.6 million in 2012. Neurosurgeons are therefore required to be well acquainted with dementia diagnosis and treatment. In this report, I have outlined our knowledge of dementia and the workings of the Japanese social security system that neurosurgeons should know.
According to a new concept for cerebrospinal fluid (CSF) dynamics, CSF is not produced mainly from the choroid plexus, and it is not absorbed from the arachnoid granule near the superior sagittal sinus, rather it is drained mainly by the lymphatic systems around the cranial nerves or lower cervical nerve root. Furthermore, CSF moves in a pulsatile fashion with blood circulation and respiration as the driving force and does not flow in one direction from the ventricle to the subarachnoid space (bulk flow theory). The CSF pulsatile movement is normally the largest around the cisterna magna and prepontine cistern. The mean total volume of intracranial CSF was ≥300 ml in the healthy controls at 70 years, <300 ml in the patients with secondary normal pressure hydrocephalus (sNPH) in which pathogenesis is thought to be due to the inflammatory adhesion in the widespread subarachnoid spaces, and ≥400 ml in the patients with idiopathic NPH (iNPH). Compared with the healthy 70-year-old controls, the patients with iNPH have about 100 ml larger ventricles and almost the same size of subarachnoid space, but the CSF distribution in the subarachnoid spaces was very different between the iNPH patients and age-matched controls. In iNPH, the Sylvian fissure and basal cistern were conspicuously enlarged, whereas the convexity part of the subarachnoid space was severely decreased. The CSF distribution in the subarachnoid space in iNPH is known to be characterized as disproportionately enlarged subarachnoid space hydrocephalus (DESH) which might be due to direct CSF communication between the lateral ventricles and the basal cistern at the inferior choroidal point of the choroidal fissure, acting as the overflow device for the ventricular drainage system. These alternative direct CSF pathways between ventricles and subarachnoid spaces other than the foramina of Luschka and Magendie have been reported. Also, the CSF distribution pattern in iNPH differed strongly from that in sNPH.
The Ministry of Health, Labor and Welfare has announced that “in 2050, the number of patients with dementia is expected to exceed 10 million,” and we face the pressing issue of taking measures to address the increasing number of dementia patients. Until now, psychiatrists and neurologists have taken the lead in the treatment of dementia, but in recent years, neurosurgeons, particularly private practitioners, have come to play a role as well. Furthermore, in order to realize a society in which those with dementia can enjoy a better quality of life, we neurosurgeons are expected to play a critical role in constructing a community-based integrated care system.
After completion of training for dementia support, since 2007 I have organized a series of lectures titled “Open Lectures about Strokes and Dementia for Citizens.” The presenters are not only physicians but also experts with various specializations, and the dementia-related content covers many fields. In addition, I have also given talks to audiences including local residents, physicians, nurses, pharmacists, dentists, care managers, home care service providers, dental hygienists, physical therapists, occupational therapists, and speech therapists.
In the future, with the cooperation of administrative agencies and educational institutions, I plan to conduct information campaigns targeted at the next generation ; work for effective use of libraries and similar facilities ; and, in coordination with local stakeholders, promote the use of regional resources.
Telemedicine has been defined as a remote communication system using information and communication technology (ICT) between doctors or between doctor and patient. Recent advances in ICT including mobile devices and wireless local area networks have enabled adequate telemedicine communication between definite points and mobile points. With the ever-increasing demands of stroke management, using telemedicine to shorten decision making time is becoming an important factor in best-practice treatment. This article summarizes the importance and unsolved issues of telemedicine associated with neurosurgical practice.
Brain sag may result from post-craniotomy over-drainage or the leakage of cerebrospinal fluid. We treated a patient in whom it was caused not by the loss of cerebrospinal fluid but by its decreased production. A 72-year-old man who had previously undergone gastrectomy underwent a right superficial temporal artery to middle cerebral artery bypass. On postoperative Day 8 he lapsed into a coma and imaging showed a midline shift, and craniotomy was therefore performed again. However, there were no signs of elevated intracranial pressure, and a diagnosis of brain sag due to low cerebrospinal fluid pressure was reached. The blood concentration of retinol-binding protein was low, and decreased cerebrospinal fluid production due to vitamin A deficiency was indicated to be the cause. The patient improved after conservative treatment consisting of vitamin A supplementation. This condition should be borne in mind in the event of unexpected impairment of consciousness or if indicated by imaging findings after craniotomy.
A 65-year-old man presented with acute headache followed by a week of nuchal and back pain. A computed tomography (CT) scan demonstrated a subarachnoid hemorrhage and varices in the basal cistern and cerebral angiography revealed a dural arteriovenous fistula (dAVF) of the lesser sphenoid wing region. The lesion was treated by endovascular surgery. Onyx (ethylene vinyl alcohol copolymer) was used for transarterial embolization. We review some anatomical and therapeutic features involving dAVF of this region and describe the feasibility and technical notes for the use of Onyx in the treatment of these lesions.
We describe a 75-year-old man with rare traumatic vertebral artery injury (TVAI) complicated with a vertebral giant pseudoaneurysm and an arteriovenous fistula. He had been involved in a traffic accident and arrived at our hospital by ambulance in a comatose, tetraplegic state. Initial CT findings revealed cervical subluxation between C4 and C5, and CT angiography (CTA) showed aneurysmal dilation arising from an obliterated left VA at the C4/5 level. Repeat CTA on the following day showed that the aneurysm had rapidly expanded to 3 cm. Emergency angiography revealed complete occlusion of the left VA at the C4/5 level with a giant pseudoaneurysm and a vertebral artery arteriovenous fistula (VA-AVF) with drainage to the external vertebral plexus. The contralateral right VA was also occluded. Endovascular internal trapping of the left VA, including the giant pseudoaneurysm, was followed by cervical spine fixation. The patient was then transferred to a rehabilitation center. Serial CTA and coil embolization of a giant pseudoaneurysm and an AVF were safely performed, and effectively prevented fatal bleeding in this patient with severely traumatic cervical injury.