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Biomedical subjects

O Masuo

Publications and source records attributed to O Masuo.

17 recordsLinked to original sources
PubMed2005

Endovascular treatment of unruptured cerebral aneurysms.

76 consecutive patients with 78 unruptured cerebral aneurysms underwent endovascular therapy from July 1999 to May 2004 in our institute. For the wide-necked aneurysms, the remodeling technique, double microcatheter technique, or stent-assisted coil embolization was used, while a parent artery occlusion or covered stent was applied for the giant or fusiform aneurysms. Immediate angiographical results demonstrated 33 complete occlusions, 26 neck remnants, and 14 dome fillings. Four cases were treated with parent occlusion or stenting only, and one case was not treated with embolization but with clipping due to the rupture of the aneurysm during coil embolization. Immediate angiographic findings demonstrated that in aneurysms between 5 to 10 mm, the rate of complete occlusion was 48%, that of neck remnants 33%, and that of dome fillings 27%. In aneurysms between 11 to 25 mm, the rate of complete occlusion was 14%, that of neck remnants 28%, and that of dome fillings was 58%. In the angiographic follow-up results, all aneurysms smaller than 5 mm showed complete occlusion. In aneurysms between 5 to 10 mm, 74% of the aneurysms showed complete occlusion, and 21% showed neck remnants, and 5% showed dome filling. In aneurysms between 10 to 24 mm, 25% showed complete occlusion, while 75% showed dome filling. The overall mortality rate was 0% and the morbidity rate was 3.7% (2 major strokes, 1 minor stroke) at 30-days after embolization. In the clinical follow-up study, one case of a large basilar tip aneurysm caused a fatal rupture 28 months after the initial embolization. Endovascular therapy was performed on the unruptured aneurysms and was found to be an acceptable treatment, except for durability in cases of large aneurysms.

Adult↗
PubMed2002

Indirect carotid cavernous fistula appeared after balloon embolization of direct CCF.

The authors describe a case of indirect carotid cavernous fistula (CCF) appearing five months after embolization for traumatic direct CCF, which was treated six months after the trauma. Long-term (six months) venous hypertension to the affected cavernous sinus due to direct CCF and cavernous sinus thrombosis following a balloon embolization were considered as an etiology of the de novo dural arteriovenous fistula. The recurrent symptoms of CCF are usually related to detached balloon disorder, but delayed recurrence may be caused by the de novo dural AVF, if the direct CCF was treated in the chronic state.

Arteriovenous Fistula↗
PubMed2001

Memory impairment and spatial disorientation following a left retrosplenial lesion.

We treated a patient in whom a left retrosplenial lesion resulted in memory impairment and spatial disorientation. A 31 year old, right handed man was admitted to our hospital after the sudden onset of headache. He was alert, attentive and cooperative, and showed no motor or sensory deficits. Although intelligence was preserved, memory was obviously deficient. The patient proceeded in wrong directions after he left his hospital room and subsequently his home. Neuroimaging revealed a subcortical hematoma in the left cingulate isthmus, while single-photon emission computed tomography demonstrated decreased perfusion in the splenium and left parietal lobe.

Adult↗
PubMed2000

Treatment of restenosis after percutaneous transluminal angioplasty for internal carotid artery stenosis.

The efficacy of repeated percutaneous transluminal angioplasty (PTA) and carotid endarterectomy (CEA) was examined in patients with restenosis after PTA for carotid stenosis. After percutaneous transluminal angioplasty (PTA) for 63 cases of internal carotid stenoses 13 cases of restenosis appeared. They were treated by PTA or carotid endarterectomy. The treatment was chosen by the patient after explanation of each treatment. We initially treated seven patients by repeat PTA and six by carotid endarterectomy. The degree of stenosis improved from 82% to 30% on average after repeated PTA. However, one patient in the PTA group had restenosis, and carotid endarterectomy was then performed. The other cases also had restenosis and were treated by PTA. The six cases treated by carotid endarterectomy were successfully treated without difficulty. The success rate of PTA was 5/7 (71%) in the restenosis cases. Patients with a greater residual stenosis after initial PTA had significantly more frequent restenosis. Repeat PTA and CEA both appeared effective treatment for restenosis after initial PTA, although PTA had a restenosis rate similar to that of initial PTA.

Aged↗
PubMed2000

Haemorrhagic complication following percutaneous transluminal angioplasty for carotid stenosis.

We report 2 cases with haemorrhagic complications following percutaneous transluminal angioplasty (PTA) for carotid stenosis. Computed tomography (CT) scanning of these cases demonstrated diffuse subarachnoid haemorrhage in 1 case, and intracerebral haemorrhage in the other case on the next day after PTA. In the latter case, we measured cerebral blood flow velocity and mean transit time with transcranial doppler (TCD) and dynamic CT scan, which demonstrated remarkable increases in the blood flow velocity and peak height, respectively. From these results, postoperative hyperperfusion was suggested to have caused haemorrhagic complications.

Aged↗
PubMed2000

Regression of a presumed meningioma with the antiestrogen agent mepitiostane. Case report.

This 68-year-old woman underwent a distal gastrectomy for gastric cancer in August 1994. A presumed meningioma of the falx was found incidentally on a staging examination of the gastric cancer, but the meningioma was not treated with surgery. Instead, after gastrectomy the patient received tegafur as adjuvant chemotherapy until February 1996, when she was readmitted to the hospital because of loss of appetite and emaciation but with no recurrence of the gastric cancer. A computerized tomography scan obtained during this second admission showed no change in the meningioma. To improve her general condition, tegafur was discontinued and she was started on a course of the antiestrogen agent mepitiostane. Administration of mepitiostane for approximately 2 years resulted in a marked regression (73%) of the meningioma. This is the first reported case of a presumed meningioma that regressed as a result of use of the antiestrogen agent mepitiostane.

Adenocarcinoma, Papillary↗
PubMed2000

[Agenesis of the right internal carotid artery associated with complicated anastomosis of middle cerebral artery: a case report].

A 57-year-old female was admitted to our hospital because of headache, nausea, and vomiting. Head CT scan demonstrated subarachnoid hemorrhage. Cerebral angiography showed the absence of the right internal carotid artery, and skull base CT of the bone window level revealed the absence of the right carotid canal. The right middle cerebral artery (MCA) and anterior cerebral artery (ACA) were opacified from the left internal carotid artery. The right A1 portion was hypoplastic and the distal portion of the right M1 portion was replaced by several minute complicated anastomotic vessels connected to the right M2 portion. The right MCA territory was mainly supplied by collateral flow from the right ACA and the right posterior cerebral artery via the leptomeningeal anastomosis. These was neither aneurysm nor arteriovenous malformation. The second angiography, 1 week after the initial angiography, showed the same hemodynamic pattern and aneurysms were not found. We diagnosed the patient as agenesis of the right internal carotid artery and the etiology of subarachnoid hemorrhage was suspected to be a rupture of the anastomotic vessels between the right M1 and M2. She was discharged on the 21st hospital day without any neurological deficit.

Carotid Artery, Internal↗
PubMed1999

Transcortical sensory aphasia due to a left frontal subcortical haemorrhage.

A case of transcortical sensory aphasia caused by a cerebral haemorrhage in the left frontal lobe is presented. A 72-year-old right-handed woman was admitted to the hospital, with a history of acute onset of speech disturbance and headache. On initial assessment, her spontaneous speech was fluent. She had no difficulty initiating speech, articulated normally, and did not exhibit logorrhea. Her ability to repeat phonemes and short sentences (5-6 words) was fully preserved, however she had severe difficulty with visual recognition of words, and with aural comprehension at the word level, although she was able to read words aloud. Computed tomography and magnetic resonance imaging showed cerebral haemorrhage in the left frontal lobe, involving the superior and middle frontal gyrus. Single photon emission CT revealed a wider area of low perfusion over the entire left frontal lobe, including the superior, middle and inferior frontal gyrus. The aphasia symptoms, mainly poor comprehension, disappeared quickly several weeks after the event. This may have been due to a reduction in the size of the haematoma and a resolution of the oedema around the haematoma. Clinically, the transcortical sensory aphasia in this case was indistinguishable from that caused by damage to the posterior language areas. Further case reports of transcortical sensory aphasia associated with frontal lobe lesions would help to confirm whether a relatively rapid recovery is characteristic in cases such as this.

Aged↗
PubMed1999

A case of amnestic syndrome caused by a subcortical haematoma in the right occipital lobe.

A case of an amnestic syndrome caused by a subcortical haematoma in the right occipital lobe is reported. A 62-year-old right-handed man presented with a sudden onset of headache to the hospital. On admission, he had a left homonymous hemianopsia, disorientation and recent memory disturbance, but had normal remote memory and digit span. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a subcortical haematoma in the right occipital lobe. These findings suggest that the patient's amnesia was caused by a lesion of the retrosplenial region in the non-dominant hemisphere.

Amnesia↗
PubMed1999

[Construct validity of a new computer-assisted cognitive assessment battery in normal adults].

A computer-assisted battery for neuropsychological tests (CNT) has been designed to screen adults for cognitive impairment. The aim of this study was to gather evidence for the construct validity of CNT and also investigate the relationship between CNT and conventional neuropsychological tests. Subjects were 45 healthy adults (21 men and 24 women), who ranged in age from 20 to 70 years (mean = 33.5, SD = 1.9) with no history of substance abuse, or of psychotic or neurological disorders. The CNT in our study consists of six subtests designed to assess various components of driving, such as digit span, visual scanning, visual and verbal memory, complex reaction time, and vigilance. Mini-mental state test, Kana-hiroi test, word fluency, the auditory-verbal learning test and Raven's colored progressive matrices were also performed as conventional neuropsychological tests. Results showed there were high correlations between each CNT subtests and conventional neuropsychological tests. A factor analysis (with varimax rotation) identified 4 factors with eigen values greater than 1, which accounted for over 70% of the variance. CNT was able to estimate each factor related to cognitive function such as learning and memory, attention, judgment, and visual scanning selectively. CNT may thus be a useful tool for detection of cognitive impairment, although this test has important limitations. Broader applications of these tests will require extensive population-based validation.

Adult↗
PubMed1999

[Dural arteriovenous fistula at the cranio-cervical junction presenting transient ischemic attack: a case report].

A 58-year-old male was admitted to our hospital because of repeated transient ischemic attack of right hemiparesis and speech disturbance. A CT scan did not demonstrate any remarkable findings. No significant cerebral arterial stenosis or occlusion was found on angiography. However, dural arteriovenous fistula fed by the radiculo-meningeal artery was found at the cranio-cervical junction on left vertebral angiography. The shunt flow from the arteriovenous fistula drained into the superior petrosal sinus and sigmoid sinus in a retrograde fashion. On the angiographic findings when his transient ischemic attack (TIA) had disappeared, the venous drainage had returned to its normal fashion. Venous hypertension around the brain stem was supposed to have caused the transient ischemic attack in this case. We performed coagulation of the draining vein and fistula surgically. After surgery, the patient's TIA completely disappeared. We report the first case of dural arteriovenous fistula at the cranio-cervical junction presenting transient ischemic attack.

Aged↗
PubMed1998

Carotid endarterectomy and simultaneous percutaneous transluminal angioplasty for tandem internal carotid stenoses.

We treated three patients with tandem internal carotid stenoses in single procedures including carotid endarterectomy (CEA) for the proximal stenosis and percutaneous transluminal angioplasty (PTA) for the distal stenosis. We devised a Y-shaped shunt tube for the CEA, through which a balloon catheter was introduced to perform PTA guided by mobile digital subtraction angiography. No cerebrovascular events occurred during follow-up. Our approach avoids the risk of a second procedure while effectively treating tandem stenoses.

Aged↗
PubMed1998

[A case of agraphia due to cerebral infarction in the left parietal lobe].

A case of agraphia due to cerebral infarction in the left parietal lobe was reported. A 63-year-old right-handed man was admitted to our hospital with writing disturbance. His spontaneous speech was fluent, and object naming, word fluency, repetition, verbal comprehension, and reading were fully preserved. However, his writing was slow and required effort. He showed hesitation in spontaneous writing and dictation. His power to copy was better than his power to write spontaneously or to take dictation, but he had some difficulty in copying letters and complex figures. The patient showed abnormal sequences of strokes and completed his strokes by piecing out of several fragments. CT scan and MRI showed a cerebral infarction in the left parietal lobe which included the superior parietal lobule. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. The characteristics of his agraphia much more closely resembled "apractic agraphia", as reported by Alexander et al (1992), than spatial agraphia or pure agraphia. Agraphia in this patient might result partially from the loss or unavailability of the memory of motor patterns necessary for writing letters.

Agraphia↗
PubMed1997

[Syringomyelia appearing in a short term after brain abscess].

We describe a rare case of syringomyelia that developed within only 4 months after the cure of the focal cerebritis and abscess. An 18-year-old man who had suffered from meningitis and brain abscess 1.5 years before, presented with pain and sensory disturbance in his left shoulder. Magnetic resonance image (MRI) showed a syrinx formation extending from the upper cervical to the lower thoracic cord. Investigation by MRI during the course of the brain abscess had the appearance of posterior cerebellar arachnoid cyst 3 months after the onset of brain abscess and syrinx developed within 9 months. After posterior fossa decompression and reopening of the Magendie's foramen, his symptom and MRI abnormality improved after one month. In contrast to reported cases of syringomyelia following cerebritis, syrinx formation in our case appeared in relatively a short time. We speculated that basal arachnoiditis and the formation of posterior cerebellar arachnoid cyst caused syrinx formation in a short term after cerebritis.

Adolescent↗
PubMed1997

[A case of cerebral aneurysm using a goose neck snare to stabilize the guiding catheter during embolization].

Severe arteriosclerotic changes often prevent navigating a guiding catheter into an appropriate position during aneurysm embolization. A basilar superior cerebellar artery aneurysm was found in a patient who had had subarachnoid hemorrhage 6 months previously. We selected embolization for this aneurysm using Guglielmi detachable coils (GDC) because of its highly located position from the dorsum sellae. We could not introduce a guiding catheter into the distal portion of the vertebral artery because of severe arteriosclerotic changes and it easily prolapsed into the aorta when a microcatheter was navigated through the guiding catheter positioned in the proximal vertebral artery. We were able to successfully perform embolization of the aneurysm by fixing a guiding catheter at the origin of the left vertebral artery with a goose neck snare wire introduced from the left brachial artery. The authors emphasize that a snare wire is useful not only for retrieval of foreign bodies but also for fixing a guiding catheter during aneurysm embolization, especially in which prolapse of the guiding catheter may cause a serious complication.

Catheterization↗
PubMed1995

[A case of spinal dural arteriovenous fistula associated with normal pressure hydrocephalus].

A 62-year-old male presented with urinary incontinence, gait disturbance and dementia for 6 months. Neurological examination revealed severe paraparesis (1/5), sensory disturbance below Th10, neurogenic bladder and absence of patellar and achilles tendon reflexes. CT scan showed mild brain atrophy and symmetric ventriculomegaly with periventricular lucency. Magnetic resonance imaging (MRI) showed a linear flow void lesion on the dorsal surface on the back of his swollen lower spinal cord. Myelography showed a filling defect and flow disturbance of contrast medium in lower thoracic levels, suggesting the presence of adhesive arachnoiditis. Spinal angiography demonstrated a fistula formation between dural branches of bilateral L4 lumbar arteries and ventral spinal and radicular veins on the surface of the dura mater of L4/5 levels. Considering his past history of repeated lumbar puncture for tuberculous meningitis at the age of 22 years, a diagnosis of acquired spinal dural arteriovenous fistula probably due to repeated lumbar puncture was made. Fistulas were embolized with N-butyl cyanoacrylate. And normal pressure hydrocephalus was treated by ventriculoperitoneal shunt. Follow-up CT scans showed a decrease of the size of the ventricular system. Etiology of acquired spinal arteriovenous fistula has been reported. In the case, repeated lumbar puncture may be a possible cause of arteriovenous fistula in the lower spinal dura mater. However, the reason why it took so long to form a fistula after the lumbar puncture remains to be elucidated. We suggest that an increased protein concentration due to disturbance of cerebrospinal fluid flow might be a cause of normal pressure hydrocephalus (NPH).

Arteriovenous Fistula↗