E Urasaki

University of Occupational and Environmental Health, Kitakyūshū, Fukuoka, Japan

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Publications (72)51.63 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Spinal intramedullary glioblastoma has rarely been reported. Among reported cases, the most characteristic features are rapid progression of the disease and very poor prognosis. The mean survival period is 12 months. We report a patient having cervical intramedullary glioblastoma with long-term survival (26 months after the onset). A 21-year-old man presented with weakness in bilateral hands, and the symptoms progressed rapidly. Magnetic resonance imaging (MRI) showed cervical intramedullary tumor. He underwent surgery of debulking of the cervical tumor, fractionated stereotactic irradiation, and repeated chemotherapy using nimustine hydrochloride (ACNU). Although dissemination of the tumor in the intracranial space deteriorated the patient, he survived for 26 months after the initial onset. It has been reported that no treatment is effective for this disease. However, it is also true that some patients respond well to the intensive treatment. It can be emphasized that scheduled intensive treatment for the disease under earlier histological confirmation should be performed.
    Journal of UOEH 01/2009; 30(4):413-20.
  • N. Akamatsu, S. Tsuji, E. Urasaki
    Clinical Neurophysiology - CLIN NEUROPHYSIOL. 01/2007; 118(10).
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    ABSTRACT: To determine the characteristics of high-frequency oscillations (HFOs) of cortical somatosensory evoked potentials (SEPs), the effect of general anesthesia on HFOs and low-frequency primary cortical responses was studied. The authors recorded SEPs elicited by median nerve stimulation directly from human brains of seven patients who underwent implantation of subdural electrodes before surgical treatment of intractable epilepsy. Recordings were made before and during general anesthesia. Changes in the number of HFOs and amplitude ratios of HFOs/primary cortical responses were analyzed. Under general anesthesia, the number of HFO peaks and the amplitude ratios were significantly decreased. General anesthesia induced remarkably decreased HFO activities when compared to low-frequency SEPs, suggesting that each of those originated from different generators. Possible relations between gamma-amino-butyric acid (GABA)ergic inhibitory interneurons and HFOs are discussed.
    Journal of Clinical Neurophysiology 11/2006; 23(5):426-30. · 1.45 Impact Factor
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    ABSTRACT: We present a variant of a split cord malformation with coexisting segmental spinal dysgenesis. CT myelography showed the left hemicord with a small remnant of subarachnoid space running through an intravertebral cleft in a spine anomaly. The left hemicord had no apparent intradual connection to the upper cord on any radiologic examination, though functional electrical stimulation studies revealed an intact efferent pathway that connected the left hemicord to the main spinal cord.
    American Journal of Neuroradiology 09/2006; 27(7):1562-4. · 3.17 Impact Factor
  • Eiichirou Urasaki, Akira Yokota
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    ABSTRACT: We describe two patients complaining of vertigo associated with a small supra-tentorial convexity meningioma. Symptoms disappeared after tumor removal, providing evidence for an association between the vertigo and the cerebral cortical lesions. Tumors were located in the central and parietal areas, respectively, which are probably analogous to the vestibular cortex in the areas designated 3av, 2v, and 7 in animal studies.
    Journal of Clinical Neuroscience 02/2006; 13(1):114-6. · 1.25 Impact Factor
  • Eiichirou Urasaki, Rieko Maeda, Naoki Akamatsu, Akira Yokota
    Supplements to Clinical neurophysiology 02/2006; 59:159-65.
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    ABSTRACT: Ibudilast, an antagonist of platelet-activating factor receptors, was administered to patients with chronic subdural hematoma (CSDH) to assess its effectiveness in preventing recurrence. The remaining volumes of subdural hematomas on brain computed tomography were measured approximately 1-2 months after using ibudilast. The hematomas were significantly smaller and there was no recurrence. Ibudilast administration may be useful in the prevention of recurrence of CSDH.
    Journal of UOEH 01/2006; 27(4):377-83.
  • Clinical Neurophysiology - CLIN NEUROPHYSIOL. 01/2006; 117:167-168.
  • Masaru Idei, Eiichirou Urasaki, Akira Yokota
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    ABSTRACT: The authors presented a patient with metastatic brain tumor originating from urachal carcinoma. A 64-year-old female was admitted to our hospital with complaints of memory disturbance, indifference and apathy of 3 months duration. Head CT and MRI on admission showed a round mass with perifocal edema in the right frontal lobe. After administration of Gd-DTPA, the mass lesion showed ringed enhancement effect. Pelvic MRI scan revealed a bladder tumor, which was diagnosed as urachal carcinoma. The brain lesion was suspected to have metasta sized metastatic from urachal carcinoma, and was excised by craniotomy. Histology of the brain tumor was identical to that of urachal carcinoma. Postoperatively the patient received local radiation therapy, but died of multiple metastasis to lung and local recurrence, 18 months later. Urachal carcinoma is an extremely rare tumor, comprising 0.17-0.34% of all bladder tumors. Though this rare tumor carries a poor prognosis, it may be effective for longer survival of a patient to treat the metastatic brain lesion with surgery and radiation.
    No shinkei geka. Neurological surgery 11/2005; 33(10):1015-9. · 0.13 Impact Factor
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    ABSTRACT: A 44-year-old man presented with an endolymphatic sac tumor (ELST) associated with von Hippel-Lindau disease, which required four surgical procedures within 10 years. The earlier two surgeries resulted in only partial removal of the tumor because of vigorous intraoperative bleeding. Stereotactic radiation therapy was performed twice. The intraoperative bleeding was easy to control in the third operation, and ultimately the tumor was totally extirpated in the fourth operation. Histological examination of the tumor specimen harvested in the final surgery showed that the tumor cells had clearly decreased in number, and the interstitial tissue had become fibrous with organization of the tumor vessels, compared with the tumor specimen from the first surgery. Preoperative radiotherapy may be effective to reduce the devastating intraoperative bleeding of ELST.
    Neurologia medico-chirurgica 12/2004; 44(11):595-9. · 0.49 Impact Factor
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    ABSTRACT: CASE REPORT: The authors present a case of a patient with an abdominal CSF pseudocyst that resulted from an allergic reaction to silicone. The patient underwent repair surgery of the meningomyelocele associated with the Chiari II malformation, and the V-P shunt was instituted at 6 months of age. A formation of the abdominal CSF pseudocyst and the consequent shunt malfunction were observed 40 days after the V-P shunt. An increase in the number of the peripheral eosinophils and serum immunoglobulin E (IgE), and an infiltration of eosinophils in the specimen harvested from the pseudocyst wall suggested an allergic reaction as the cause of the pseudocyst. A sixth operation to revise the V-P shunt was performed using the shunt system made of "extracted silicone", which was produced extracting the allergic substances. OUTCOME: The serum IgE was normalized after surgery and the abdominal CSF pseudocyst has not recurred for 22 months.
    Child s Nervous System 11/2004; 20(10):761-4. · 1.24 Impact Factor
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    ABSTRACT: We report a tailored temporal lobectomy for surgical treatment of medically intractable temporal lobe epilepsy. Surgery was conducted on 30 patients with temporal lobe epilepsy, 15 of whom required intracranial electrode placement. A precise skin incision had to be designed when subdural electrodes were placed, taking into consideration the electrodes' size and where they should be placed. Drawing of the Sylvian line and Rolandic line using Taylor's method on the patient's scalp provided useful information to determine the place of craniotomy. Fundamental surgical techniques and tips are described, including how to open the inferior horn after minimal removal of the lateral temporal cortex, and the introduction of a newly developed needle electrode combined with the ring type for recording electrocorticography from the exposed hippocampal surface. Twenty-three patients with mesial temporal epilepsy were treated surgically and the surgical results of 20 patients followed-up for more than one year (mean 44 months)were analyzed. Eighteen patients (90%)were seizure free (Engel class I), and 2 patients were categorized as having a significant seizure reduction (class III). Despite the good surgical results to date, further follow-up is needed to evaluate the long-term surgical effects.
    Journal of UOEH 10/2004; 26(3):303-14.
  • Tetsuya Gennmoto, Eiichirou Urasaki, Akira Yokota
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    ABSTRACT: To investigate whether the abnormality of short-latency somatosensory evoked potentials(SSEPs)in patients with focal brain lesions is enhanced by different stimulus frequencies, the median nerve at the wrist in 10 normal subjects and 12 patients with cortical (frontal, central and parietal) lesions was stimulated electrically at 1.3-18.3 Hz. Normal subjects had decreased frontal P22-N30 and parietal P27 amplitudes at high (12.3 and 18.3 Hz) stimulus frequencies, whereas the N20 amplitude was relatively preserved. Dissociated loss of frontal P22-N30 occurred in patients with frontal lesions, but the preserved parietal components had characteristics similar to those of the non-affected side or of normal subjects at the various stimulus rates, which is evidence of an independent pathway for forming the frontal components. A N20 amplitude decrease occurred at high stimulus rates in the patients with central lesions, probably because of disturbed synaptic transmission. A paradoxical amplitude increase occurred at the high stimulus rates in patients with parietal lesions, which is indicative of inhibitory function loss in the sensory cortex or thalamo-cortical networks. In conclusion, change in the stimulus frequency is a useful method for detecting sensory process alteration in patients with focal cortical lesions.
    Journal of UOEH 10/2004; 26(3):267-85.
  • Eiichirou Urasaki, Akira Yokota
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    ABSTRACT: To investigate the clinical significance of vertigo and dizziness in diagnosing cerebral cortical lesion, we analyzed 12 patients with supratentorial lesions whose chief complaint was rotational vertigo or non-rotational dizziness. There were 8 patients with right, and 4 with left hemispheric lesions. The lesion was localized in the vicinity of the central sulcus in 3 patients, temporal and/or parietal regions in 6, and occipital region in 3. Vertigo was seen in three patients, two of them with lesions in the vicinity of the central sulcus, and one in the temporo-parietal junction. The other 9 patients complained dizziness. Supratentorial lesions accompanied by dizziness or vertigo were mostly localized in temporal or central areas that were probably analogous to the vestibular cortex proposed by animal studies. Dizziness caused by occipital lesion might be due to imbalance of the neuronal network between the vestibular cortex and occipital lobe.
    Journal of UOEH 07/2003; 25(2):207-15.
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    ABSTRACT: From January 1997 to December 2001, patients with subarachnoid hemorrhage (SAH) among 14,008 residents in an isolated mountainous area; Oguni and Minamioguni towns in Kumamoto Prefecture, were evaluated. The subjects were patients being treated at Oguni Municipal Hospital. Over a period of 5 years, 19 patients were found to be suffering from SAH in this area, 3 of whom were visitors (residing outside this area). The annual incidence rate of SAH in this area was calculated as 22.9 per 100,000. The sex ratio (men:women) was 4:12. The average age was 67.9 years; 65.0 years for men and 68.8 years for women. Eleven patients were older than 65, and constituted 68.8% of the subjects. The risk factors of SAH were recognized, and both hypertension and smoking constituted 31.6%. Alcohol was 21.1% and hyperlipemia was 15.8%. In 13 clipping operated cases excluding 1 test craniotomy, Hunt & Kosnik's Grades at admission were G.I: 2, G.II: 5, G.III: 3, G.IV: 2 and G.V: 1, and Fisher's Groups were G.I: 0, G.II: 8, G.III: 3 and G.IV: 2. The sites of 16 operated aneurysms were internal carotid-posterior communicating artery (IC-PC): 2, anterior communicating artery (A Co.A): 4, middle cerebral artery (MCA): 10 and vertebral artery-basilan artery (VA-BA): 0. The aneurysmal size were < 5 mm: 5, 6-10 mm: 9 and 11 mm < :2 (average 7.6 mm, 2-15 mm). The results were evaluated at discharge, excluding 1 SAH of unknown etiology. 9 were good, 2 were dependent and 7 including 5 non-operative cases had died. We were satisfied with these results, because we were treating older patients. Although we attempted the clipping operation using only a three dimensional computed tomographic angiograply (3D-CTA; X-Vision GX (TOSHIBA) & X-Tension), we had no problem, except for 1 test craniotomy. 3D-CTA was useful during the clipping operation in the small hospital, especially, in regard to cost.
    Journal of UOEH 03/2003; 25(1):79-87.
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    ABSTRACT: To study the effects of different stimulus rates on high-frequency oscillations (HFOs) of somatosensory-evoked potentials (SEPs), we recorded median nerve SEPs directly from the human cerebral cortex. SEPs were recorded from subdural electrodes in 5 patients with intractable epilepsy, under the conditions of low (3.3Hz) and high (12.3Hz) stimulus rates. Increased stimulus rates to the median nerve from 3.3 to 12.3Hz showed a pronounced amplitude reduction of HFOs when compared with the primary N20-P20, area 3b, and P25, area 1, responses. HFOs were more sensitive to a high stimulus rate than the primary cortical responses, suggesting that the post-synaptic intracortical activities may greatly contribute to the HFO generation.
    Clinical Neurophysiology 12/2002; 113(11):1794-7. · 3.14 Impact Factor
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    ABSTRACT: Congenital absence of the internal carotid artery (ICA) is a rare anomaly and aplasia/hypoplasia of the ICA associated with other congenital malformations is uncommon, too. We report a very rare case of hypoplastic carotid canal due to hypoplastic ICA at cervical portion associated with neurofibromatosis type I (NF I). A 22-year-old male with NF I was admitted to our hospital for transient weakness of the left upper and lower limbs. Computed tomography (CT) of the brain demonstrated no abnormal findings. But bone target CT and three dimensional computed tomography (3 D-CT) showed a hypoplasia of right carotid canal. Cerebral angiography revealed that the right ICA was hypoplastic at its cervical portion and occluded at the carotid canal. Rest single photon emission computed tomography (SPECT) demonstrated normal cerebral perfusion, and SPECT with acetazolamide demonstrated showed cerebral perfusion reserve of both hemispheres, too. So he was treated conservatively at the present time. Careful follow up should be performed for such patients, because they are very rare cases and the natural history of them is unknown, too.
    Nō to shinkei = Brain and nerve 12/2002; 54(11):1003-6.
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    ABSTRACT: To investigate the neural plasticity in the somatosensory cortex, changes in somatosensory evoked potentials (SSEPs) during finger ischemia were evaluated and compared with those affected by touch or movement interference. Somatosensory evoked potentials were recorded in the vicinity of the central sulcus in four patients with intractable epilepsy. During electrical stimulation to a selected finger, ischemic anesthesia was induced in another finger. Effects of tactile or movement interference were examined during electrical stimulation to the selected finger by applying tactile stimulation to or inducing voluntary movement of the other finger. Dynamic SSEPs were recorded during varying levels of sensory deprivation and different types of interference, and the dynamic nature of the SSEP changes within an individual was studied in detail. Somatosensory evoked potential changes appeared during finger ischemia and tended to persist during the postischemic stage, which is indicative of sensory plasticity and the maintenance of new conditioning. Amplitudes of the early and late cortical components increased when complete finger anesthesia was induced-a sign of the unmasking phenomenon. Amplitudes of early cortical SSEPs decreased when ischemic anesthesia was incomplete, similar to the findings when tactile or movement interference was applied. Surrounding inhibition, therefore, may become dominant before the unmasking phenomenon appears in early cortical SSEPs.
    Journal of Clinical Neurophysiology 07/2002; 19(3):219-31. · 1.45 Impact Factor
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    ABSTRACT: A 65-year-old woman presented with a ruptured saccular aneurysm associated with a rare variation of the posterior communicating artery (PcoA), partially duplicated PcoA. The PcoA with this variation forked just distal to the aneurysmal neck, and the two branches independently merged into the posterior cerebral artery. Initial clipping failed to isolate the aneurysm from one of the two branches, so the aneurysmal dome continued to pulsate and bleed. Temporary clipping of the proximal internal carotid artery revealed the fork of the two branches just distal to the aneurysmal neck. A curved Yasargil clip was used to clip the aneurysm and preserve the PcoA and branches. Careful observation of this PcoA variation is needed because the arterial structures may be hidden by the thickened arachnoid membrane.
    Neurologia medico-chirurgica 02/2002; 42(1):23-6. · 0.49 Impact Factor
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    ABSTRACT: To examine high frequency oscillations (HFOs) of somatosensory evoked potentials (SEPs) recorded directly from subdural electrodes to investigate the relationship between the primary somatosensory cortex and HFOs. SEPs were recorded directly from subdural electrodes previously implanted in 3 patients for clinical evaluation prior to surgical treatment of intractable epilepsy. The primary sensory cortex (area 3b) was proposed as the source of somatosensory HFOs, because the distribution of HFOs recorded from the subdural electrodes agreed with the distribution of the N20-P20 components of the somatosensory evoked potential. The somatosensory HFOs showed a strictly somatotopic source arrangement. There was a polarity inversion of the prophase component and also the N20-P20 component of HFOs across the central sulcus. However, the phase was synchronized in the latter part of the HFOs. We propose that the origins of the early and latter parts of HFOs are different, and that there was a clear somatotopy.
    Clinical Neurophysiology 01/2002; 112(12):2261-4. · 3.14 Impact Factor

Publication Stats

312 Citations
51.63 Total Impact Points

Institutions

  • 1988–2007
    • University of Occupational and Environmental Health
      • Department of Neurosurgery
      Kitakyūshū, Fukuoka, Japan
  • 1998
    • Kitakyushu University
      Kitakyūshū, Fukuoka, Japan
  • 1993–1994
    • Johns Hopkins University
      • Department of Neurosurgery
      Baltimore, MD, United States