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Biomedical subjects

Koji Tokunaga

Publications and source records attributed to Koji Tokunaga.

At least 19 recordsLinked to original sources
PubMed2006

Transient memory disturbance after removal of an intraventricular trigonal meningioma by a parieto-occipital interhemispheric precuneus approach: Case report.

BACKGROUND: Pitfalls in a parieto-occipital interhemispheric precuneus approach for the ventricular trigonal region of a dominant hemisphere have been rarely reported. We described a case with memory disturbance after surgery using this approach. CASE DESCRIPTION: A 57-year-old, right-handed woman complained of numbness of the lower extremities and underwent magnetic resonance imaging, which incidentally demonstrated a trigonal meningioma in the left lateral ventricle with a maximal diameter of 4 cm. The patient's preoperative neurologic examination was normal. The tumor was successfully removed by a parieto-occipital interhemispheric approach with an incision of the left precuneus cortex. Postoperative motor, sensory, and visual functions were normal; however, recent memory disturbance developed, which gradually resolved in the following 3 months. CONCLUSIONS: An interhemispheric precuneus approach is a useful alternative to trigonal tumors with few surgical complications, but postoperative memory disturbance can be one pitfall of this procedure.

Female↗
PubMed2006

[Direct surgery for paraclinoid aneurysm arising from the anterolateral wall of the internal carotid artery].

The internal carotid aneurysm (ICA) arising from the paraclinoid region is associated with the origins of the superior hypophyseal artery and the ophthalmic artery. Recently, other aneurysms which can arise in this region without imvolvement of the arterial branches has been reported. Among those aneurysms, there are very rare type of aneurysms located on the anterolateral aspect of the internal carotid artery. In this report, we described our experience with direct surgery for five cases of the unruptuted paraclinoid aneurysm arising from the anterolateral aspect of the ICA. Firstly, the common carotid artery was exposed to carry out proximal flow control. We used the pterional approach. The anterior clinoid process was deleted after having confirmed aneurysm and the dural ring was incised. Extreme care had to be taken during this step. All patients underwent successful neck clipping. In recent two cases we employed the neuroendoscope (EndoArm) to observe the unrecognized area of surgical microscope and untrasonic bone curette (SONOPET) to perform the safe removal of the anterior clinoid process. This procedure is very useful for carrying out the neck clipping for aneurysms which are located on the anterolateral aspect of the internal carotid artery.

Adult↗
PubMed2006

[Hemifacial spasm due to vascular compression of the distal portion of root exit zone of the facial nerve: report of two cases].

It has been generally assumed that only vascular contact at the root exit zone (REZ) of the facial nerve can cause hemifacial spasm. We treated two cases of hemifacial spasm in which compression of the distal site of the REZ of the facial nerve produced symptoms. The microvascular decompression for the patients showed excellent results. Extreme care must be taken not to stretch the internal auditory artery during surgical manipulation. The ABR monitoring is useful to prevent the postoperative hearing loss. It must be kept in mind that the compression of distal portions of the facial nerve may be responsible for hemifacial spasm in cases in which neurovascular compression at the REZ is not confirmed intraoperatively.

Aged↗
PubMed2006

[Preoperative assessment of microvascular decompression for hemifacial spasm with fusion imaging of 3D MR cisternogram/angiogram].

The preoperative assessment of microvascular decompression (MVD) for hemifacial spasm has been performed with MRI, but assessment of the compressive status by 2D imaging has a number of limitations. We used a fusion image of the 3D MR cisternogram and co-registered 3D MR angiogram, reconstructed from MR cisternogram, obtained by 3D fast spin-echo sequence, and MR angiography, 3D time-of-flight and spoiled-gradient recalled sequences, for the preoperative assessment of the offending artery in 10 patients with hemifacial spasm. The anatomical relationship of the nerve-vessel complex was assessed on the simulated images, and compared with the intraoperative findings. The fusion image of the 3D MR cisternogram/angiogram depicted contours of the brain, nerves, and vessels clearly, and that allowed precise assessment of the pathogenic compression of the facial nerve by the offending vessels, comparative to the operative findings. The fusion imaging of the 3D MR cisternogram/angiogram may provide useful information in the surgical planning of MVD for hemifacial spasm.

Adult↗
PubMed2006

[Delayed hearing loss after microvascular decompression for hemifacial spasm: report of two cases].

We report two unusual cases of delayed hearing loss after microvascular decompression (MVD) for hemifacial spasm. In the first case, A 59-year-old female noted left hearing loss one week after receiving MVD for left hemifacial spasm. In the second case, A 39-year-old male also noticed ipsilateral hearing loss on the 7th day after MVD for right hemifacial spasm. Both cases were treated by steroid. Two months after the onset, their hearing function improved dramatically. These cases indicated that the delayed hearing loss after MVD for hemifacial spasm can occur, even when gentle microsurgical technique is used, but the prognosis for this condition is fairly good.

Adult↗
PubMed2005

Adult unilateral moyamoya disease with familial occurrence in two definite cases: a case report and review of the literature.

We documented an interesting case of adult "unilateral (probable)" moyamoya disease displaying familial occurrence in two "definite" cases. A 55-year-old female presented with motor aphasia, involuntary movement of the right hand and right homonymous hemianopia due to cerebral infarction. Cerebral angiography revealed typical angiographic findings on the left side and normal findings on the right side; consequently, the patient was diagnosed with probable moyamoya disease. Previously, her mother and nephew had been diagnosed with definite moyamoya disease with bilateral involvement. The patient continued to exhibit unilateral involvement on angiography for more than 4 years. Clinical features such as absence of familial occurrence suggest that most cases of probable moyamoya disease are distinct from definite cases, especially in adults. To the best of our knowledge, this report appears to be the first involving an adult probable case characterized by familial occurrence. The literature pertaining to adult probable moyamoya disease was reviewed and the etiology of this disease was discussed.

Aphasia, Broca↗
PubMed2005

Brain stem ischemia from intracranial dural arteriovenous fistula: case report.

BACKGROUND: Intracranial dural arteriovenous fistulas (AVFs) with spinal perimedullary venous drainage are rarely reported, but most of the patients initially have presented with myelopathy or subarachnoid hemorrhage. This is the first report of the intracranial dural AVF patient who presented with brain stem infarction. CASE DESCRIPTION: A 38-year-old woman experienced nausea and vomiting with an acute onset, followed by vertigo. Magnetic resonance imaging showed ischemic lesion in the medulla oblongata, and she was then sent to our hospital. On admission, she had nystagmus, swallowing difficulties, Homer syndrome, and right hemiparesis and hemisensory disturbance. Cerebral angiography revealed dural AVF draining into spinal perimedullary veins at the left transverse-sigmoid sinus. The patient was treated by transvenous embolization under local anesthesia. A microcatheter proceeded to the left sigmoid sinus via the internal jugular vein, and embolization of the sinus was performed using coils without complications. The patient's swallowing difficulties improved over a few days after the embolization, and one month later, there remained only a slight mild hemiparesis and hemisensory disturbance. Six months after the onset, there was no ischemic lesion in the brain stem on magnetic resonance imaging. CONCLUSIONS: In this case, we showed the possibility of brain stem infarction, caused by the intracranial dural AVF.

Adult↗
PubMed2005

Enhanced brain angiogenesis in chronic cerebral hypoperfusion after administration of plasmid human vascular endothelial growth factor in combination with indirect vasoreconstructive surgery.

OBJECT: Vascular endothelial growth factor (VEGF) is a secreted mitogen associated with angiogenesis. The conceptual basis for therapeutic angiogenesis after plasmid human VEGF gene (phVEGF) transfer has been established in patients presenting with limb ischemia and myocardial infarction. The authors hypothesized that overexpression of VEGF using a gene transfer method combined with indirect vasoreconstruction might induce effective brain angiogenesis in chronic cerebral hypoperfusion, leading to prevention of ischemic attacks. METHODS: A chronic cerebral hypoperfusion model induced by permanent ligation of both common carotid arteries in rats was used in this investigation. Seven days after induction of cerebral hypoperfusion, encephalomyosynangiosis (EMS) and phVEGF administration in the temporal muscle were performed. Fourteen days after treatment, the VEGF gene therapy group displayed numbers and areas of capillary vessels in temporal muscles that were 2.2 and 2.5 times greater, respectively, in comparison with the control group. In the brain, the number and area of capillary vessels in the group treated with the VEGF gene were 1.5 and 1.8 times greater, respectively, relative to the control group. CONCLUSIONS: In rat models of chronic cerebral hypoperfusion, administration of phVEGF combined with indirect vasoreconstructive surgery significantly increased capillary density in the brain. The authors' results indicate that administration of phVEGF may be an effective therapy in patients with chronic cerebral hypoperfusion, such as those with moyamoya disease.

Animals↗
PubMed2005

[Sequentially occurred bilateral atlantoaxial rotatory subluxation following craniotomy: a case report].

Atlanto-axial rotatory subluxation (AARS) often presents in childhood as a stiff, painful neck with associated typical cock-robin type of torticollis. It can occur spontaneously or following minor trauma or an inflammatory process in the cervical tissues or following otorhinolaryngeal surgery. We report a case of bilateral AARS which occurred sequentially following craniotomy. To the best of our knowledge, no case of AARS after craniotomy has been reported previously and only one case in which bilateral AARS was observed has been reported to date. Failure to recognize the condition may result in a fixed rotatory subluxation, which can be difficult to treat. Awareness of this condition by surgeons involved in brain surgery should lead to its early recognition and treatment, preventing a fixed deformity occurring. We discuss the clinical presentation and management of AARS. The literature on this subject is briefly reviewed.

Astrocytoma↗
PubMed2005

Visualization of aneurysmal contours and perianeurysmal environment with conventional and transparent 3D MR cisternography.

We have developed conventional and transparent 3D MR cisternography to investigate the spatial relationship between the contours of aneurysmal complex and the perianeurysmal structures including the cranial nerves, dural fold, cranial base bone, and brain parenchyma. Volume data obtained by a T2-weighted 3D fast spin-echo sequence were reconstructed by using a perspective volume-rendering algorithm with a transluminal imaging technique. 3D MR cisternograms provide useful anatomic information in the therapeutic and follow-up management of unruptured cerebral aneurysms.

Aged↗
PubMed2005

[Assessment of the signal intensity distribution pattern within the unruptured cerebral aneurysms using color-coded 3D MR angiography].

To evaluate the interaction between the MR signal intensity distribution pattern and bleb formation/ deformation of the aneurysmal dome, fifty cases of the unruptured cerebral aneurysms were investigated with the color-coded 3D MR angiography. Patterns were categorized into central-type, neck-type and peripheral-type according to the distribution of MR signals with low-, moderate- and high signal intensity areas. Imaging analysis revealed the significant relationship (P < 0.02) of the peripheral-type aneurysms to the bleb formation and deformation of the dome, compared with those of central- and neck-type. Additionally, peripheral-type signal intensity distribution pattern was shown with aneurysms harboring relatively large dome size and lateral-type growth including internal carotid aneurysms. Prospective analysis of intraaneurysmal flow pattern with the color-coded 3D MR angiography may provide patient-specific analysis of intraaneurysmal flow status in relation to the morphological change of the corresponding aneurysmal dome in the management of unruptured cerebral aneurysms.

Adolescent↗
PubMed2005

[Assessment of the perianeurysmal environment of unruptured internal carotid-posterior communicating artery aneurysms with fusion imaging of three-dimensional magnetic resonance cisternography and angiography].

The anatomical relationship of an unruptured internal carotid-posterior communicating artery aneurysm and the perianeurysmal environment was investigated by using three-dimensional (3D) magnetic resonance cisternography (MRC), angiography (MRA) and newly developed fusion images of 3D MRC and 3D MRA. Contact of an aneurysm with the adjacent intra- and pericisternal structures was observed in cases with the aneurysm developing and extending beyond the capacity of the surrounding subarachnoid space. Deformation and bleb formation of the aneurysmal dome was depicted at the dome in contact with the perianeurysmal environment, including the tentorial edge, the anterior petroclinoid dural fold, the oculomotor nerve, the posterior clinoid process, the dorsum sellae and the cranial base bone. By using the fusion imaging technique of 3D MRC and 3D MRA, assessment of the contact of an unruptured cerebral aneurysm with its perianeurysmal environment can be made. Such contact gives ride to risk of deformation and bleb formation of the aneurysmal dome; and may result in cranial nerve symptoms and accelerate rupture from an unruptured cerebral aneurysm.

Aged↗
PubMed2005

[Percutaneous vertebroplasty combined with radiofrequency ablation for a patient with a spinal metastatic tumor: case report].

Recent technological development has allowed expanding applications of radiofrequency ablation (RFA) for malignant tumor therapy. We report a case with a spinal metastatic tumor treated with combination of percutaneous vertebroplasty (PVP) that provides pain relief and spinal stabilization and RFA. A 68-year-old male who had undergone resection of left ureteric carcinoma was referred to our hospital with lower back pain due to the fifth lumbar (L5) vertebral metastatic tumor. Conventional radiation therapy was discontinued because of pneumonia. One year later, the patient was admitted again with weakness of the right knee and foot and severe pain of the back and the right lower extremity. Radiographs demonstrated a compressive fracture of the L5 vertebra predominantly on the right side. CT and MRI showed a tumor of the L5 body invading the right pedicle, the intervertebral foramen, and the retroperitoneal space. RFA was performed in the ventral part of the L5 body, and then around the right L5/the first sacral intervertebral foramen. Temperature and time for ablation ranged from 74 degrees C to 95 degrees C and from 11 min. to 30 min., respectively. Next, PVP was performed by the right transpedicular approach. Bone cement was injected into the L5 body and the pedicle by an amount of 3.0 ml in total without technical complications. Postoperatively, visual analogue scale demonstrated decreased pain degree from 10 cm to 5.4 cm. Combined treatment with RFA and PVP is a feasible and promising procedure for spinal metastatic tumors. Further evaluation is necessary to confirm its long-term efficacy.

Aged↗
PubMed2005

Influence of perianeurysmal environment on the deformation and bleb formation of the unruptured cerebral aneurysm: assessment with fusion imaging of 3D MR cisternography and 3D MR angiography.

BACKGROUND AND PURPOSE: Surface irregularity and bleb formation are anatomical factors that are associated with aneurysm rupture. The perianeurysmal environment has been proposed as one factor that may influence aneurysm morphology. We have developed a fusion imaging technique of 3D MR cisternography and angiography that allows clear visualization of an aneurysm and its environment. This technique may prove useful in further understanding of the natural history of intracranial aneurysms. METHODS: Fusion images of 3D MR cisternography and angiography were reconstructed by a perspective volume-rendering algorithm from the volume datasets of MR cisternography, obtained by a T2-weighted 3D fast spin-echo sequence, and coordinated MR angiography, by a 3D time-of-flight sequence. On the fusion images, the anatomic relationship of an aneurysm to the perianeurysmal structures was assessed, and the influence of perianeurysmal environment on the deformation and bleb formation of the aneurysm was investigated. RESULTS: Marked and minor deformation and bleb formation of the aneurysmal dome were found at the areas confronted or adjacent to a certain contact with perianeurysmal structures, including cranial nerves, brain parenchyma, cranial base bones, petroclinoidal dural folds, and dura mater. CONCLUSION: Fusion images of 3D MR cisternography and angiography can depict the contact of an aneurysm with its perianeurysmal environment; this may provide an additional parameter in consideration for the natural history of cerebral aneurysms.

Aged↗
PubMed2004

Combined use of electrolytically and mechanically detachable platinum coils for endovascular treatment of cerebral aneurysms--technical note.

The combined use of Guglielmi detachable coils (GDCs) and newly developed mechanically detachable platinum coils (Detach Coil System: DCS) was evaluated for the endovascular treatment of 10 patients with cerebral aneurysms. The number and total length of detachable coils placed into the aneurysms, the detaching time for each coil, and any technical problems were recorded and evaluated. Sixty GDCs and 60 DCSs were used. The detachment time for the DCS (mean 21 seconds) was faster than that for the GDC (mean 2 minutes 35 seconds). One DCS moved inside the aneurysm during the mechanical detachment maneuver, but was successfully placed. Neither detachment system influenced the behavior of the other system during coil implantation. The DCS includes a useful J-shape coil, whereas the GDC can be detached safely in fragile aneurysms. The DCS is also cheaper. The coil systems complemented one another and the combination optimized cost and operating time.

Adult↗
PubMed2004

Persistent primitive trigeminal artery-cavernous sinus fistula with intracerebral hemorrhage: endovascular treatment using detachable coils in a transarterial double-catheter technique. Case report and review of the literature.

Intracerebral hemorrhage occurred in this 61-year-old woman with preexisting diplopia and proptosis. Results of angiography demonstrated a persistent primitive trigeminal artery (PPTA)-cavernous sinus fistula with cortical venous reflux. Two microcatheters were introduced transarterially through the PPTA into the two draining pathways in the cavernous sinus. Coils were delivered in both pathways simultaneously to prevent further venous overload on either path. The fistula was successfully occluded without complication while the PPTA was preserved. The authors describe this double-catheter technique for coil embolization of a fistula and review the literature concerning PPTA-cavernous sinus fistulas.

Catheterization↗