Keisuke Tsutsumi

NHO Nagasaki Medical Center, Nagasaki, Nagasaki, Japan

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Publications (96)133.92 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: With new neuroimaging techniques, the detection rate of unruptured intracranial aneurysms has increased. While most detected aneurysms are small and left untreated because of the low risk of rupture, we still encounter many cases of small aneurysm rupture. Middle cerebral artery(MCA)aneurysms have lower risk of rupture compared to those in the anterior cerebral or internal carotid-posterior communicating arteries. Identification of small aneurysms with a high risk of rupture is important to improve management of these aneurysms. We report 10 cases of ruptured tiny(<3mm)MCA aneurysms. All patients underwent clipping and nine had good outcomes. One patient had poor outcome due to the worsening of chronic heart failure and kidney failure. A tiny aneurysm can rupture if the aneurysmal wall is fragile. Therefore, the fragility of the aneurysmal wall is an important predictive factor of rupture. Presently, however, it is difficult to determine when an operation for an unruptured tiny aneurysm is indicated; new neuroimaging techniques that detect the fragility of the aneurysmal wall are needed.
    No shinkei geka. Neurological surgery 03/2015; 43(3):207-13. DOI:10.11477/mf.1436202988 · 0.13 Impact Factor
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    ABSTRACT: Stem cell transplantation has emerged as a promising new experimental treatment for stroke; understanding its mechanism of action will facilitate the translation of stem cell therapy to the clinic. The ultimate change in brain plasticity is manifested at the synaptic level, however, the synaptic remodeling after stem cell therapy remains unknown. Vehicle or human neural progenitor cells (hNPCs) derived from fetal cortex were transplanted into the ischemic cortex of Nude rats at 7 days after distal middle cerebral artery occlusion. Transplantation of hNPCs significantly improved behavioral recovery after stroke compared to vehicle-treated rats at 3–4 weeks post-transplantation. We found that transplanted stem cells enhanced endogenous brain repair processes including structural brain plasticity. hNPC-treated rats had a higher density of glutamatergic synapses in layer 5 at 4 weeks posttransplantation, compared to vehicle-treated rats. These results provide novel new information about the organization of synaptic circuitry and its plasticity after stem cell therapy. These data suggest that stem cells alter the synaptic remodeling of glutamatergic synapses after stroke and this is coincident with stem cell-induced functional recovery.
    01/2015; 26(2):151-154. DOI:10.16977/cbfm.26.2_151
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    ABSTRACT: Cerebral aneurysm re-rupture following subarachnoid hemorrhage(SAH)is a serious problem that is related with poor outcome. It is generally said that re-rupture occurs within 6 hours of the initial SAH;in the acute stage, strict management is needed even in the period before hospitalization. The aim of this study was to confirm whether patients on isolated islands should be transferred by helicopter > 6 hours after the initial SAH. Here we reviewed 125 cases of SAH in the isolated islands of Nagasaki prefecture between January 2007 and December 2012 who were transferred to Nagasaki Medical Center by helicopter as a result of consultation via TeleStroke(41 men, 84 women;mean age, 65.76 years). Re-rupture was observed in seven patients(5.6%), five of whom were diagnosed with re-rupture in a prior hospital on the isolated island. No patients demonstrated clinical deterioration during transport. Early helicopter transportation under adequate sedation and control of blood pressure within 6 hours is safe, and patients should be transferred as quickly as possible during the day. On the other hand, at night, flight safety must first be considered. Patients in stable clinical condition may be transferred the next day. We should pay special attention to patients with SAH and intracerebral hemorrhage, severe SAH, or vertebral artery dissecting aneurysm because their condition may gradually become more serious even if initially stable.
    No shinkei geka. Neurological surgery 06/2014; 42(6):537-43. · 0.13 Impact Factor
  • Surgery for Cerebral Stroke 01/2014; 42(1):51-57. DOI:10.2335/scs.42.51
  • Surgery for Cerebral Stroke 01/2014; 42(1):1-8. DOI:10.2335/scs.42.1
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    ABSTRACT: Developmental venous anomalies(DVAs), that have been previously called venous malformation, are extreme variations of normal transmedullary veins that are necessary for the drainage of white and gray matter. They are becoming the most commonly encountered intracranial vascular lesions in central nervous system imaging. Most DVAs are asymptomatic or uncomplicated, and surgery is no longer considered necessary. The author describes a rare case of an 8-year-old patient presenting with massive cerebellar hemorrhage due to DVA with diffuse arteriovenous(A-V)shunt. Cerebral angiography demonstrated diffuse A-V shunt from the basilar artery runs into the bilateral basal vein of Rosenthal through the enlarged transpontine vein. Caput medusae-like appearance was visualized, although the finding of nidus was not obvious. Moreover, three-dimensional computed tomography angiography demonstrated stenosis in part of the drainage routes. Then, we supposed that this lesion was a transitional form between a DVA and an arteriovenous malformation, and massive cerebellar hemorrhage might be caused by secondary venous hypertension due to venous stenosis. A careful follow-up should be made, because the prognosis of DVA with A-V shunt has not been fully elucidated.
    No shinkei geka. Neurological surgery 07/2013; 41(7):619-625. · 0.13 Impact Factor
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    ABSTRACT: We recently encountered experienced a rare case of transient pupil-sparing oculomotor nerve palsy(PSONP)caused by an aneurysm at the junction of the internal carotid-and posterior communicating arteries(IC/PC AN)in an 87-year-old, non-diabetic woman. She initially presented with diplopia 4 years previously, and was diagnosed, based on incomplete right oculomotor paresis without pupil involvement(PSONP), as external ophthalmoplegia. MR-angiography revealed a long protrusion of the IC/PC AN with posterior-inferior projection, for which she chose to receive conservative management. Thirty nine months later, she presented with another transient PSONP. CT angiography(CTA)showed that the aneurysm was enlarged in the posterior-inferior direction. Two days after this last CTA imaging, the aneurysm ruptured with upward enlargement of the bleb. Despite complete external ophthalmoplegia and ptosis, her pupil involvement was still minimal and transient. By reviewing reported cases and our own case, we found that a narrow and long aneurysm body and posterior-inferior projection are characteristic for the IC/PC AN that causes PSONP, implying a possible mechanism for PSONP by upward compression of the oculomotor nerve. Though rare in its incidence, IC/PC AN could present with PSONP prior to their rupture. Therefore, immediate imaging evaluation in patients presenting with PSONP is essential to prevent devastating rupture events.
    No shinkei geka. Neurological surgery 06/2013; 41(6):507-14. · 0.13 Impact Factor
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    ABSTRACT: Background: Mild cerebrospinal fluid (CSF) hypovolemia is a well-known clinical entity, but critical CSF hypovolemia that can cause transtentorial herniation is an unusual and rare clinical entity that occurs after craniotomy. We investigated CSF hypovolemia after microsurgical aneurysmal clipping for subarachnoid hemorrhage (SAH). Method: This study included 144 consecutive patients with SAH. Lumbar drainage (LD) was inserted after general anesthesia or postoperatively as a standard perioperative protocol. CSF hypovolemia diagnosis was based on three criteria. Results: Eleven patients (7.6%) were diagnosed with CSF hypovolemia according to diagnostic criteria in a postoperative range of 0-8 days. In all patients, signs or symptoms of CSF hypovolemia improved within 24 hours by clamping LD and using the Trendelenburg position. Conclusions: As a cause of acute clinical deterioration after aneurysmal clipping, CSF hypovolemia is likely under-recognized, and may actually be misdiagnosed as vasospasm or brain swelling. We should always take the etiology of CSF hypovolemia into consideration, and especially pay attention in patients with pneumocephalus and subdural fluid collection alongside brain sag on computed tomography. These patients are at higher risk developing of pressure gradients between their cranial and spinal compartments, and therefore, brain sagging after LD, than after ventricular drainage. We should be vigilant to strictly manage LD so as not to produce high pressure gradients.
    Acta Neurochirurgica 05/2013; 155(8). DOI:10.1007/s00701-013-1755-4 · 1.77 Impact Factor
  • Clinical neurology and neurosurgery 01/2013; 115(8). DOI:10.1016/j.clineuro.2012.12.021 · 1.13 Impact Factor
  • Surgery for Cerebral Stroke 01/2013; 41(5):343-351. DOI:10.2335/scs.41.343
  • Ichiro Kawahara · Keisuke Tsutsumi · Izumi Nagata
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    ABSTRACT: As you know, atherosclerosis is a serious public problem and is the leading cause of morbidity and mortality not only in Western countries but also in Asia. Cervical carotid disease is typical atherosclerosis, which is responsible for ischemic stroke. Recently, it has been well established that the risk of an acute event mediated by rupture is predicated by plaque components rather than by the degree of luminal narrowing. Preoperative evaluation of plaque components by some modalities such as magnetic resonance imaging is very important for a decision of the treatment strategy. Generally, vulnerable plaques are characterized by a large lipid core, a thin fibrous cap, and substantial infiltration with inflammatory cells. Recently, evidence is accumulating for a role of the immune system and neovascularization in the progression of atherosclerosis. Neovascularization may act as a conduit for the entry of immune and inflammatory cells. Dendritic cells, macrophages, and T-lymphocytes play a main role in the immune-inflammatory system of atherosclerotic lesions, in which they form the vascular-associated lymphoid tissue(VALT)network together. The immune-inflammatory system in the VALT network plays a role in determining the dynamic balance between collagen degradation and collagen synthesis. On the other hand, some of these consecutive mechanisms related with plaque vulnerability have not yet been clarified. To clarify them, we should keep on researching the formation process of atherosclerotic carotid plaque from the pathohistological viewpoint.
    No shinkei geka. Neurological surgery 01/2013; 41(1):5-13. · 0.13 Impact Factor
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    ABSTRACT: Polyarteritis nodosa (PAN) is a rare, systemic necrotizing vasculitis of small and medium size arteries that leads to aneurysms in various organs. Aneurysms associated with PAN are common in visceral arteries, however, intracranial aneurysms are rare, especially in childhood. A pediatric patient with PAN developed serial hemorrhagic strokes from a ruptured superior cerebellar artery aneurysm (subarachnoid hemorrhage) and a de novo aneurysm of the frontoorbital artery (intracerebral hemorrhage) after 9 months. Patients with PAN who present with intracranial aneurysms are candidates for intervention even if the aneurysm is unruptured and still small, and close observation is needed to detect de novo aneurysms in patients with chronic history of PAN.
    Neurologia medico-chirurgica 12/2012; 52(12):928-32. DOI:10.2176/nmc.52.928 · 0.72 Impact Factor
  • Clinical neurology and neurosurgery 07/2012; 115(4). DOI:10.1016/j.clineuro.2012.05.044 · 1.13 Impact Factor
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    ABSTRACT: We recently encountered a rare case of anterior cerebral artery dissection (ACAD) that accompanied fresh cerebral infarction (CI) and subarachnoid hemorrhage (SAH). An initial head CT showed a thin SAH in the interhemispheric cistern and cortical sulcus of the left frontal surface. Subsequent MRI performed 10 min after head CT scan revealed a fresh infarction in the left ACA region. MR-and digital subtraction angiograms demonstrated a dissection in the A2 portion of the left ACA with a leak of contrast media around the left A3 portion, suggesting that the bleeding occurred in a distal portion of the main dilation. Without anti-thrombotic therapy, the patient recovered without complications by blood pressure control and administration of brain-function protection therapies. We found 11 cases similar to the present case in the literature. All cases presented with lower-extremity dominant hemiparesis; however, sudden onset headache was rare. Blood pressure was not well-controlled in 4 out of the 6 known hypertensive cases. Main sites of dissection were located at the A2 portion in all cases except one A3 lesion, and extended to A3 in 2 cases. Conservative therapy led to favorable outcome in 8 cases, while 4 cases underwent surgical interventions for increasing risk of aneurysm rupture after initial observational therapies. Re-bleeding did not occur in any of the 12 cases reviewed. These data suggest that conservative treatment can be considered for an initial management of ACAD with simultaneous CI and SAH. More evidence needs to be accumulated to establish the optimal therapeutic approach for ACAD associated with CI and SAH.
    No shinkei geka. Neurological surgery 07/2012; 40(7):635-42. · 0.13 Impact Factor
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    ABSTRACT: A 61-year-old woman presented with dementia, 7 years after an operation for retroperitoneal leiomyosarcoma. Magnetic resonance imaging (MRI) revealed enhanced masses with perifocal edema in the bilateral frontal regions and a very small mass in the right medial frontal region. The tumors in the bilateral frontal regions were completely removed surgically, and γ-knife radiotherapy was administered for the very small tumor in the right medial frontal region. The histological diagnosis was metastatic leiomyosarcoma. Postoperatively, an MRI showed that the perifocal edemahad decreased, and the symptoms gradually improved. Cerebral metastasis from a retroperitoneal leiomyosarcoma is very uncommon. Ideally, the tumors should be surgically removed because radiotherapy and chemotherapy are apparently ineffective. A combination of complete surgical removal and γ-knife radiotherapy may be effective in prolonging patient survival.
    Brain and nerve = Shinkei kenkyū no shinpo 05/2012; 64(5):565-9.
  • Surgery for Cerebral Stroke 01/2012; 40(1):28-34. DOI:10.2335/scs.40.28
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    ABSTRACT: To evaluate the efficacy and safety of CT angiography (CTA) performed at immediate early postoperative periods in patients with ruptured intracranial aneurysm, we retrospectively analyzed the modality and timing of postoperative evaluation following clip placement for ruptured intracranial aneurysms in our institution during the last decade. Between 2001 and 2007 (Phase A: 281 cases), postoperative evaluation with digital subtraction angiography was performed on or after 14 postoperative days (POD) in the majority of the subjects, except for some postoperative imaging that was done earlier. Re-ruptures were observed in five cases (1.8% of total cases in Phase A), of which three aneurysms bled within two weeks after surgery. Since 2008, we have used the CTA for evaluation in the early postoperative period (Phase B: 102 cases). In particular, after 2009, all patients underwent immediate (POD 1) CTA to exclude aneurysm remnants as early as possible. No adverse incidence was observed during this protocol. In the Phase B period, two small remnants of anterior communicating artery aneurysms (AcomAN, 2.0% of all cases in Phase B) were detected in the CTA on POD 1. The patients in whom aneurysm remnants were found immediately underwent a second surgery to prevent re-rupture. Our findings suggest that immediate postoperative examination (POD 1) by CTA is beneficial to detect an incomplete closure of aneurysms before the postoperative vasospasmic phase. CTA was particularly useful in cases with aneurysms remnant in deeper locations such as AcomAN. Early postoperative evaluation with CTA, therefore, should be considered to reduce risk for devastating re-bleeding during the early postoperative period in patients who undergo clipping surgery for ruptured intracranial aneurysms.
    Surgery for Cerebral Stroke 01/2012; 40(3):164-172. DOI:10.2335/scs.40.164
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    ABSTRACT: A 61-year-old man with a history of cerebellar infarction was transferred to our hospital for the treatment of vertebral artery (VA) stenosis. The VA dissection was treated with endovascular stent placement followed by coil embolization in which shrinkage of the dissecting aneurysm was confirmed by the three-dimensional driven equilibrium (3D DRIVE) sequence. Using 3D DRIVE, the outer contour of the aneurysm was well visualized, free from the influence of the metallic devices. 3D DRIVE may be useful in the follow-up assessment of the vertebrobasilar artery after stent-assisted coil embolization.
    Neurologia medico-chirurgica 01/2012; 52(4):205-8. DOI:10.2176/nmc.52.205 · 0.72 Impact Factor
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    ABSTRACT: Dolichoectasia of the intracranial arteries is a rare condition, and the vertebrobasilar system and the internal carotid artery are the most commonly involved structures. We report a rare case of idiopathic dolichoectasia of the anterior cerebral artery in a 22-year-old female. The patient caused an automobile accident and was brought to our hospital in an ambulance. A computed tomography scan and magnetic resonance imaging revealed no fresh lesions, but showed a prominent serpentine structure with calcification and flow void in the region of the interhemispheric fissure, which was suspicious for arteriovenous malformation or arteriovenous fistula. Cerebral angiography demonstrated extensive dilatation of the anterior cerebral artery, but no evidence of arteriovenous malformation or arteriovenous fistula. Single photon emission computed tomography revealed hypoperfusion of the right frontal lobe at rest. Electroencephalography showed no epileptic discharge. The patient's course was uneventful, and she was discharged with no neurologic deficit. There are few reports of hemodynamic changes in cases of dolichoectasia. In the diagnosis of cerebral dolichoectasia, cerebral hemodynamics should be examined carefully in addition to evaluating vascular disease by angiography.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 10/2011; 21(8). DOI:10.1016/j.jstrokecerebrovasdis.2011.07.017 · 1.67 Impact Factor
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    ABSTRACT: Hypertensive intracerebral hemorrhage (HICH) causes significant morbidity and mortality. The time required to transport the patients to a specialized hospital can influence the prognosis. In the isolated islands in Nagasaki prefecture, there is no medical institution which can offer emergent neurosurgical intervention. We reviewed the cases of HICH in this region from January 2006 to September 2010, who were transferred to Nagasaki Medical Center by a helicopter after consultation via teleradiology. Eighty four cases (23%) were transferred via helicopter to our institution from isolated islands. In three of them (4%), re-hemorrhage was demonstrated on computed tomography after helicopter transportation, and one of three had been administered an anti-coagulant agent. Only one case (1%) has deteriorated during helicopter transportation because of acute obstructive hydrocephalus. The outcome at discharge was as follows: modified Rankin Scale (mRS) I: 3 cases (4%), II: 5 cases (6%), III: 3 cases (4%), IV: 30 cases (36%), V: 31 cases (37%), VI: 12 cases (14%), 43 cases (51%) showed poor outcome (mRS V, VI). For medical management in isolated islands, a remote teleradiology system is indispensable to decide a strategy of treatment rapidly, and a helicopter transportation system is very useful in cases requiring emergent neurosurgical intervention, particular in cases of impending cerebral herniation or acute hydrocephalus. However, we may need to expand logistical supporting hospitals or secure other transportation facilities because many of the patients with poor outcome can not return to their home islands.
    No shinkei geka. Neurological surgery 10/2011; 39(10):963-8. · 0.13 Impact Factor

Publication Stats

872 Citations
133.92 Total Impact Points


  • 2009–2013
    • NHO Nagasaki Medical Center
      • Department of Neurosurgery
      Nagasaki, Nagasaki, Japan
  • 2005–2009
    • Nagasaki University
      Nagasaki, Nagasaki, Japan
  • 1988–2008
    • Nagasaki University Hospital
      Nagasaki, Nagasaki, Japan
    • National Institute of Mental Health (NIMH)
      • Laboratory of Clinical Science
      베서스다, Maryland, United States