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Featured researches published by Akatsuki Wakayama.


Pediatric Neurosurgery | 2003

Tethered Cord Associated with Anorectal Malformation

Kazuyoshi Morimoto; Osamu Takemoto; Akatsuki Wakayama

Ten children with a tethered cord and also an anorectal malformation are reported in this document. The anorectal malformations comprised 5 vesicointestinal fissures, 2 cloacal exstrophies, 2 rectovesical fistulas and 1 rectobulbar fistula. All of the patients underwent colostomy in advance of surgery for untethering of the spinal cord. Although their neurologic deficits had previously been considered static, they were subjected to radiographic examination of the caudal spine and found to have a tethered cord. These 10 children were among 55 children with a tethered cord surgically treated at the Division of Neurosurgery of the Osaka Medical Center and Research Institute for Maternal and Child Health during the last 11 years. Data were obtained for these 10 children (6 boys and 4 girls, mean age 1.7 years) who underwent surgical untethering. Several hypotheses are offered to explain this association. Anorectal malformations are related to underlying spinal cord anomalies, which may be amenable to neurosurgical correction. Eight of our patients had no skin stigma of the lumbosacral region, in contrast to an ordinary tethered cord. Spinal cord imaging is necessary to closely scrutinize these children.


Pediatric Neurosurgery | 2005

Spinal Lipomas in Children – Surgical Management and Long-Term Follow-Up

Kazuyoshi Morimoto; Osamu Takemoto; Akatsuki Wakayama

Since its introduction, MR imaging has been easy to perform on all children with lumbosacral cutaneous stigmata, and has enabled the phenomenal refinement of spinal pathology. We investigated the overall outcomes of children with spinal lipomas at the Osaka Medical Center and Research Institute for Maternal and Child Health in Osaka, Japan. Between 1991 and 2003, 76 children with a tethered cord underwent a total of 90 surgical procedures at our institutes. Of this cohort, 67 cases had spinal lipomas. The mean age of patients at first operation for asymptomatic lipoma was 22.4 months (range: 1 month to 16 years, trim mean: 10.1 months, mode: 5 months), except 4 cases. The mean total follow-up for the cohort since the first surgical procedure was 7.2 years (trim mean: 7.9 years). Since the introduction of MR imaging, the reoperation rate for symptoms or signs in our series was 16.4% (11 cases). Regarding the 13 subsequent reoperations (2 patients had 2 operations), 3 patients were reoperated on due to multiplication of the lipomas after untethering, 3 due to urologic symptoms and 5 due to orthopedic signs. There were 2 cases who also had to undergo reoperation early due to CSF leakage. Filum and conus lipomas have similar tethering pathologies, but differ in the outcome following surgery. Filum lipomas are benign, and therefore surgery is safe and effective. Conus lipomas are more difficult to manage.


Brain & Development | 1994

Serial IMP-SPECT and EEG studies in an infant with hemimegalencephaly

Tetsuzo Tagawa; Kazumasa Otani; Yasuyuki Futagi; Akatsuki Wakayama; Kazuyoshi Morimoto; Yoshiki Morita

An 8-month-old girl of hypomelanosis of Ito associated with hemimegalencephaly had frequent seizures beginning 44 h after birth. The seizures were secondarily generalized or unilateral initially, followed by infantile spasms at about 1.5 months of age. Frequent partial seizures appeared at 4 months of age. [123I]N-Isopropyl-p-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) was performed serially during an interictal period at 1, 3 and 7 months of age. At 1 and 3 months, IMP-SPECT showed a marked increase of IMP uptake in the pathological left hemisphere and electroencephalography (EEG) revealed left-sided dominant hypsarrhythmia. At 7 months of age, a reversal was seen, there being decreased uptake on SPECT in the pathological hemisphere and abundant high amplitude background activity mingled with epileptic discharges on EEG in the non-pathological hemisphere. These serial changes of IMP uptake on SPECT seemed to reflect either changes in epileptic activity or maturational changes in cerebral perfusion in hemimegalencephaly.


Journal of Neurosurgery | 2007

Dissecting aneurysm of the radiculomedullary artery originating from extracranial vertebral artery dissection in a patient with rheumatoid cervical spine disease: an unusual cause of subarachnoid hemorrhage. Case report.

Shingo Toyota; Akatsuki Wakayama; Yasunori Fujimoto; Shiro Sugiura; Toshiki Yoshimine

The authors report the case of a 65-year-old woman with atlantoaxial subluxation caused by rheumatoid arthritis. The patient had been hospitalized because of an infection after a total-knee replacement, when she suddenly lost consciousness and became apneic after an episode of intractable neck pain. Cranial computed tomography scanning demonstrated subarachnoid hemorrhage (SAH), and angiography revealed a dissecting aneurysm of the radiculomedullary artery that had originated from an extracranial vertebral artery dissection at the level of the atlantoaxial joint. Although coil embolization for the parent artery, including the dissecting aneurysm, was performed successfully, the patient died of worsening infection. The authors believe that the SAH occurred because of a ruptured dissecting aneurysm in the intradural portion of the radiculomedullary artery.


Journal of Neurological Surgery Reports | 2014

Unruptured Internal Carotid-Posterior Communicating Artery Aneurysm Splitting the Oculomotor Nerve: A Case Report and Literature Review

Shingo Toyota; Takuyu Taki; Akatsuki Wakayama; Toshiki Yoshimine

Objective To report a rare case of unruptured internal carotid-posterior communicating artery (IC-PC) aneurysm splitting the oculomotor nerve treated by clipping and to review the previously published cases. Case Presentation A 42-year-old man suddenly presented with left oculomotor paresis. Three-dimensional digital subtraction angiography (3D DSA) demonstrated a left IC-PC aneurysm with a bulging part. During surgery, it was confirmed that the bulging part split the oculomotor nerve. After the fenestrated oculomotor nerve was dissected from the bulging part with a careful microsurgical technique, neck clipping was performed. After the operation, the symptoms of oculomotor nerve paresis disappeared within 2 weeks. Conclusions We must keep in mind the possibility of an anomaly of the oculomotor nerve, including fenestration, and careful observation and manipulation should be performed to preserve the nerve function during surgery, even though it is very rare.


Neurologia Medico-chirurgica | 2015

Retreatment of Recurrent Internal Carotid-Posterior Communicating Artery Aneurysm after Coil Embolization.

Shingo Toyota; Takuyu Taki; Akatsuki Wakayama; Toshiki Yoshimine

Internal carotid-posterior communicating artery (IC-PC) aneurysms account for more than 20% of all intracranial aneurysms. As a result of the increase in coiling, there has also been an increase in recurrent IC-PC aneurysms after coiling. We present our experience of 10 recurrent IC-PC aneurysms after coiling that were retreated using surgical or endovascular techniques in order to discuss the choice of treatment and the points of clipping without removal of coils. From 2007 to 2014, 10 recurrent IC-PC aneurysms after coiling were retreated. When the previous frames covered the aneurysms all around or almost around except a part of the neck, coiling was chosen. In other cases, clipping was chosen. Clipping was attempted without removal of coils when it was technically feasible. Among the 10 IC-PC aneurysms retreated, 3 were retreated with coiling and 7 were retreated with clipping. In all three cases retreated with coiling, almost complete occlusion was accomplished. In the seven cases retreated with clipping, coil extrusion was observed during surgery in six cases. In most of them, it was necessary to dissect strong adhesions around the coiled aneurysms and to utilize temporary occlusion of the internal carotid artery. In all seven cases, neck clipping was accomplished without the removal of coils. There were no neurological complications in any cases. The management of recurrent lesions of embolized IC-PC aneurysms requires appropriate choice of treatment using both coiling and clipping. Clipping, especially without the removal of coils, plays an important role in safe treatment.


Pediatric Neurosurgery | 2004

High-grade spinal cord tumor with cerebellar and retroperitoneal extension.

Kazuyoshi Morimoto; Akatsuki Wakayama; Toshiki Yoshimine; Masahiro Nakayama

Accessible online at: www.karger.com/pne A 4-month-old girl presented with a 3-week history of fecal incontinence and a 1-week history of paraparesis. She exhibited no voluntary motion of the lower extremities. Spinal magnetic resonance imaging revealed an intradural intramedullary mass under the T9 region that exhibited a swelling cord with an area of high intensity on T1-weighted imaging (fig. 1a). A preoperative brain CT scan 2 weeks later revealed another multiple cerebellar enhanced lesion, although the initial CT scan had not revealed any lesion (fig. 1B). The patient underwent laminotomy and posterior fossa craniectomy, and then partial excision of the spinal and cerebellar tumors. Examination of formalin-fixed, paraffinembedded sections of the cerebellar masses showed poorly differentiated, pleomorphic cells with marked nuclear atypia and brisk mitotic activity (fig. 1C). However, the histology of the spinal tumor was not verified. Although craniospinal irradiation (50 Gy) in addition to chemotherapy was performed for 3 months, abdominal and back distension appeared. An axial body CT scan revealed an enormous retroperitoneal extension (fig. 1D). She died 2 weeks later. At autopsy, the spinal cord tumor was found to extend through the intervertebral foramen to the retro-


Neurologia Medico-chirurgica | 2015

Superior Turbinectomy: Role for a Two-surgeon Technique in Endoscopic Endonasal Transsphenoidal Surgery—Technical Note

Yasunori Fujimoto; Henrique Faria Ramos; Pedro Paulo Mariani; Fabrizio Ricci Romano; Arthur Cukiert; Edson Bor-Seng-Shu; Akatsuki Wakayama; Toshiki Yoshimine

We describe a practical technique of superior turbinectomy followed by posterior ethmoidectomy as a less invasive procedure for two-surgeon technique on endoscopic endonasal transsphenoidal surgery. After identification of the superior turbinate and the sphenoid ostium, the inferior third portion of the superior turbinate was coagulated and resected. This partial superior turbinectomy procedure exposed the posterior ethmoidal sinus. Resection of the bony walls between the sphenoid and posterior ethmoid sinuses provided more lateral and superior exposure of the sphenoid sinus. This technique was performed in 56 patients with midline skull base lesions, including 49 pituitary adenomas and 7 other lesions. Meticulous manipulation of instruments was performed in all cases without surgical complications such as permanent hyposmia/anosmia or nasal bleeding. Our findings suggested that the partial superior turbinectomy followed by retrograde posterior ethmoidectomy is a simple and safe technique providing a sufficient surgical corridor for two-surgeon technique to approaching midline skull base regions, mainly involving pituitary adenomas.


Neurologia Medico-chirurgica | 2014

Modified hemostatic technique using microfibrillar collagen hemostat in endoscopic endonasal transsphenoidal surgery: technical note.

Yasunori Fujimoto; Taisuke Kobayashi; Masahiro Komori; Pedro Mariani; Edson Bor-Seng-Shu; Manoel Jacobsen Teixeira; Akatsuki Wakayama; Toshiki Yoshimine

Microfibrillar collagen hemostat (MCH) is accepted as an effective topical hemostatic agent during endoscopic endonasal transsphenoidal surgery (EETS), particularly to achieve venous hemostasis; however, handling MCH may be troublesome because of its adherence to gloves and instruments. We describe here a method of “injection” of MCH suspension using a syringe applicator. This technique allows a rapid and precise delivery of MCH to the bleeding points and thereby results in effective hemostasis; in addition, it is easy to prepare and it is also inexpensive.


Archive | 1983

The Role of Intracranial Blood Volume in Mechanical and Pharmacological Decompression

Mamoru Taneda; Akatsuki Wakayama; K. Ozaki; K. Yagi

The cerebral vascular bed is one of the intracranial comPartments which undergoes rapid change. However, it remains unresolved how it responds to decompression. Some decompressive treatment resulting in an increased vascular bed may adversely affect the vascular system by encouraging engorgement of the vascular bed if vasoparalysis is a major etiological factor in increased intracranial pressure, as reported by Langfitt et al. (1966). The present study was carried out to investigate the response of intracranial blood volume (ICBV) during decompression.

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Toshiki Yoshimine

Brigham and Women's Hospital

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