Biomedical subjects

Yasunori Takemoto

Publications and source records attributed to Yasunori Takemoto.

4 recordsLinked to original sources

PubMed2006

Endodermal cyst ventral to the lower brain stem.

A 28-year-old woman presented with a rare case of endodermal cyst located ventral to the lower brain stem manifesting as recurrent aseptic meningitis. Computed tomography and magnetic resonance imaging demonstrated a cystic mass located ventral to the lower brain stem and extending from the prepontine to the upper cervical (C-2) cistern. The lesion was totally removed through a retrosigmoid craniotomy and C1-2 hemilaminectomy. Histological and immunohistochemical examination showed the cyst was derived from the endoderm. The histological diagnosis was endodermal cyst. Early diagnosis and surgical removal are important for patients with these cysts.

Adult↗

PubMed2004

Plasma cell myeloma of the skull base: report of two cases.

Plasma cell myeloma (PCM) of the skull base is rarely encountered in neurosurgical practice. PCM has a wide spectrum of pathology, including a quite benign, solitary plasmacytoma (SPC), and an extremely malignant, multiple myeloma (MM) at the two ends of the spectrum. We have described two patients with PCM of the skull base, of which one harbored SPC, and the other progressed to MM. In case 1, a 46-year-old man presented with left multiple cranial nerve impairments and had a large skull base tumor. Subtotal removal was performed. The specimen and general examination, including bone marrow aspiration, revealed SPC. Postoperatively 50Gy of external radiotherapy was administered. The patient has no manifestation of MM 24 months after the initial presentation. In case 2, a 53-year-old woman presented with left abducens palsy and had a left petroclival osteolytic mass. Gross total resection was performed. The specimen revealed a plasmablastic tumor, i.e., myeloma. General examination established the diagnosis of MM. She was administrated adjuvant chemotherapy and autologous bone marrow transplantation. She is alive without local recurrence 30 months after the initial presentation.

Diagnosis, Differential↗

PubMed2004

Combined pre- and retrosigmoid approach for petroclival meningiomas with the aid of a rotatable head frame: peri-auricular three-quarter twist-rotation approach: technical note.

We used the combined subtemporal presigmoid and suboccipital retrosigmoid multidirectional approach with the aid of a rotatable head frame (periauricular three-quarter twist-rotation approach) in 20 cases of petroclival meningiomas. Patients were placed in the lateral decubitus (park-bench) position. The head is twisted, rotated, and positioned 30 degrees face down in the Sugita rotatable head frame. By rotating this head frame, a 30- to 60-degree face-down position can be obtained when the suboccipital retrosigmoid route is used. Alternatively, the straight lateral or slightly brow-up position is obtained when the subtemporal presigmoid route is used. This twist-rotation approach provides multiple trajectories through the petroclival region with minimal drilling of the petrous bone, fatigue of the surgeon, and retraction of the brain.

Journal Article↗

PubMed2002

[A case of post-traumatic pseudoaneurysm on the posterio meningeal artery].

A case is reported of post-traumatic delayed appearance of a pseudoaneurysm on the posterior meningeal artery. In the immediate post-traumatic stage, the patient had mild disturbance of consciousness, mild subarachnoid hemorrhage, and mid-line skull fracture of the posterior cranial fossa. At 15 hours after the trauma, the patient suddenly developed deep coma and respiratory arrest. CT scanning showed further spreading of the subarachnoid hemorrhage and newly detected subdural hemorrhage. After the patient regained spontaneous respiration, cerebral angiography was performed 24 hours after admission. This initial angiography showed no aneurysm, but at 17 days after the trauma, follow-up angiography demonstrated the delayed appearance of an aneurysmal dilatation on the posterior meningeal artery. The aneurysm was resected surgically and proved to be a pseudoaneurysm. Having developed normal pressure hydrocephalus afterwards, the patient received a V-P shunt, and was discharged 150 days after the trauma with no major neurological deficit. We discussed the indication for and timing of angiography for detecting pseudoaneurysms. Posterior meningeal artery pseudoaneurysms should be resected surgically, because intravascular surgery through the vertebral artery involves considerable risk of embolic complications.

Aneurysm, False↗