Biomedical subjects

H Otsubo

Publications and source records attributed to H Otsubo.

15 recordsLinked to original sources

PubMed1995

Neuroimaging studies in children with temporal lobectomy.

Twenty-eight children with intractable seizures who subsequently underwent a temporal lobectomy were studied by electroencephalogram (EEG), prolonged video EEG telemetry, computed tomography (CT), magnetic resonance imaging (MRI), and single photon emission computed tomography (SPECT) for the localization of epileptogenic foci. MRI showed abnormalities indicating epileptogenic foci in 21/25 patients and a increased signal intensity in 7/11 patients with mesial temporal sclerosis (MTS). SPECT showed corresponding abnormalities in 17/22 patients, including an interictal decrease in regional cerebral blood flow corresponding to the epileptogenic zone in 15. CT showed localized abnormalities in 16/28. All 12 patients with benign, slow-growing neoplasms showed an abnormality on CT scan. In children, MRI is essential in localizing epileptogenic abnormalities, especially MTS and cortical dysplasia. SPECT contributes to the localization of epileptogenic foci, which are often coincident with EEG abnormalities, particularly in single pathology. CT depicts benign neoplasms with calcification in the temporal lobe, which are likely to provoke complex partial seizures.

Adolescent↗

PubMed1995

Location of epileptic foci on interictal and immediate postictal single photon emission tomography in children with localization-related epilepsy.

Several neuroimaging techniques that supplement electrophysiologic methods of evaluating pediatric patients with localization-related epilepsies before surgery assess both structural and functional abnormalities. For example, single photon emission computed tomography (SPECT) with technetium-99m-hexamethylpropyleneamine oxime (99mTc-HMPAO) has been used to demonstrate abnormal cerebral perfusion. States of cerebral perfusion during the interictal and immediate postictal periods have been reported to correlate with epileptiform foci identified by electroencephalogram (EEG). Between January 1987 and March 1993, we studied 55 pediatric patients with intractable seizures with prolonged video EEG telemetry in the epilepsy monitoring unit, followed by computed tomography, magnetic resonance imaging, and SPECT, before surgery to determine whether SPECT studies with 99mTc-HMPAO improved the accuracy of locating the epileptic focus. Interictal SPECT was performed on all patients, and immediate postictal SPECT (within 10 minutes after seizure ended) on 17 patients monitored in the epilepsy monitoring unit. In 15 (88%) of the 17, the combination of interictal and postictal SPECT studies yielded results corresponding to the EEG abnormality, a result significantly better than that obtained from interictal studies alone: 21 (55%) of 38 (chi 2 = 5.647, P = .0175). SPECT scans showed localized abnormal perfusion in the ipsilateral temporal lobe in all six patients with mesial temporal sclerosis, but precise results were not obtained in cases of dual pathology and neuronal migration disorders. Depiction of cerebral perfusion by interictal and immediate postictal SPECT studies can lead to greater accuracy in the localization of epileptic foci.

Adolescent↗

PubMed1995

Chronic encephalitis and epilepsy (Rasmussen's encephalitis): detection of cytomegalovirus and herpes simplex virus 1 by the polymerase chain reaction and in situ hybridization.

We made a pathologic diagnosis of chronic encephalitis on surgical resections or autopsy material in 10 patients with intractable seizures and studied the specimens by immunohistochemistry for herpes simplex virus (HSV) 1 and 2 and cytomegalovirus (CMV) as well as by the polymerase chain reaction (PCR) for viral DNA sequences (HSV1, HSV2, and CMV). We also assessed eight patients (nonepileptic) with pathologically documented or clinically suspected encephalitis and five resections from epileptics without encephalitis. Immunohistochemistry for viral antigens was negative in all cases. Using PCR assay, CMV was present in six and HSV1 in two of 10 epilepsy patients with chronic encephalitis. We demonstrated CMV by in situ hybridization in two of the six patients positive for CMV by PCR. We found no viral sequences by PCR in five epileptics without encephalitis. Of the eight patients (nonepileptic) with clinically suspected or pathologically confirmed encephalitis, two cases showed CMV sequences by PCR. These observations suggest that PCR allows detection of viral sequences in some cases of chronic encephalitis associated with epilepsy that may be missed by in situ hybridization.

Adolescent↗

PubMed1995

Cholesterol emboli following percutaneous transluminal coronary angioplasty as speculated by toe skin biopsy.

A 55-year-old man required hemodialysis for acute renal failure 3 days after repeat percutaneous transluminal coronary angioplasty (PTCA). Bilateral acrocyanosis and necrotic lesions of the toes occurred 10 days after PTCA. Skin biopsy samples revealed needle-shaped cholesterol crystals of the intraluminal clefts in his small arteries. He was diagnosed with cholesterol emboli presenting as blue toe syndrome. The conditions improved with anticoagulation and vasodilation, but improvement in renal function was temporary. He later required maintenance hemodialysis. Cholesterol emboli following PTCA are life threatening because they are difficult to diagnose and can cause severe complications.

Angioplasty, Balloon, Coronary↗

PubMed1995

[RAEB in T with monosomy 7 after treatment of severe aplastic anemia with long term G-CSF].

A 19-year-old male who suffered from severe aplastic anemia had been treated with granulocyte colony stimulating factor (G-CSF) from September 1991. Marked increase of hematopoietic cells in his bone marrow was observed, and maintenance administration of G-CSF was continued. 15 months later, myeloblasts with nuclear abnormality increased, and 22 months later, myeloblasts with chromosomal abnormality presenting 46, XY, -7, +21 exceeded 20%, and aplastic anemia seemed to be transformed into refractory anemia with excess of blasts in transformation (RAEB in T). The usefulness of G-CSF in the treatment of aplastic anemia is now established, but there are some reports questioning the effect of long-term administration, especially transformation to MDS with monosomy 7. Leukemic transformation from aplastic anemia is very complex, but in some cases, long term administration of G-CSF may affect the natural course and may lead to the earlier development of leukemia.

Adult↗

PubMed1995

Use of frameless stereotaxy with location of electroencephalographic electrodes on three-dimensional computed tomographic images in epilepsy surgery.

Epileptiform activity corresponding to structural lesions was identified by three-dimensional (3D) imaging using computed tomographic (CT) scan data concurrently with scalp EEG electrodes. The electrodes, placed according to the international 10-20 system, were used to record interictal and ictal epileptogenic foci in eight patients. Electrodes placed where marked or moderate epileptiform activity was detected were replaced with markers detectable on CT. Scans with these markers on the skin were obtained and the data transferred to a 3D imaging system, and correlated with underlying cerebral structures. The reformatted images were used to assess the relation among intracranial lesions, brain surface structures, and epileptogenic zones depicted by the markers. The images help the surgeon plan a craniotomy with enough space for both lesionectomy and resection of the epileptogenic zone. In the central regions where crucial motor functions are located, the markers indicate the central fissure or postcentral gyrus. An intraoperative 3D frameless stereotactic pointing device helps in directing further examination of the epileptogenic zone. This system improves on the precision available through intraoperative electrocorticographic recording in the extratemporal lobes, thus avoiding only approximate excision of lesion and epileptogenic zone and enabling the neurosurgeon to perform epilepsy surgery with greater confidence.

Adolescent↗

PubMed1995

[Acute myelomonocytic leukemia complicated with syndrome of inappropriate secretion of antidiuretic hormone, nephrotic syndrome, and hemophagocytic syndrome].

A 59-year-old man was admitted to our hospital because of fever in August 1991. Bone marrow showed normocellularity with 41.5% of CD13, 14, 33 positive blasts, and a diagnosis of AMMoL was made. Laboratory investigation revealed hyponatremia and elevated serum ADH level, indicating the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Intensive chemotherapy successfully induced hematological complete remission and his serum sodium level became normal. In February 1992, he developed proteinuria and findings were consistent with nephrotic syndrome (NS). Renal biopsy specimen showed membranous proliferative glomerulonephritis and massive infiltration of macrophages, and his serum interleukin 6 level was elevated. Five months later, he suffered from pancytopenia and elevation of biliary enzymes with increase of hemophagocytic histiocytes in his bone marrow (hemophagocytic syndrome). He transiently responded to low dose chemotherapy but he died due to severe infection. It is interesting that association between macrophages and/or cytokines with these various complications was suggested in AMMoL.

Fatal Outcome↗

PubMed1995

[Aplastic anemia with giant splenomegaly and myelofibrosis successfully treated with antilymphocyte globulin].

Severe aplastic anemia was diagnosed in a 58-year-old female because of pancytopenia with leukocyte count 700/microliters, hemoglobin 3.4 g/dl, platelet count 4.2 x 10(4)/microliters and fatty hypoplastic bone marrow in August 1992. In January 1993, she was admitted with an abdominal skin infection caused by pseudomonas aeruginosa. After treatment of the infection, antilymphocyte globulin was given at a dose of 2,000 mg/day for four consecutive days in July 1993. This resulted in a gradual but steady improvement in her hematological data. In February 1995, her leukocyte count increased to 2,000/microliters, hemoglobin to 15.2 g/dl and platelet count to 11.0 x 10(4)/microliters. Although no splenomegaly or myelofibrosis was found previously, from April 1993, the spleen enlarged and was palpable 10 cm below the costal margin. Her bone marrow biopsy in June 1993 revealed prominent myelofibrosis. Thereafter no changes were found in these features. Splenomegaly and myelofibrosis are characteristic of primary myelofibrosis and although the relationship is uncertain, there is no previous report on aplastic anemia with splenomegaly and myelofibrosis.

Anemia, Aplastic↗

PubMed1995

Pediatric magnetic source imaging.

Magnetic source imaging has changed the perspective of managing pediatric patients with epilepsy since its introduction into clinical imaging in the pediatric population. Magnetic source imaging can be important in understanding pediatric functional neuroanatomy and for epileptic surgery in children with intractable seizures. The use and efficacy of magnetic source imaging for surgical planning and patient management is demonstrated by case reports presented in this article.

Brain Mapping↗

PubMed1993

Pathology of temporal lobectomy for refractory seizures in children. Review of 20 cases including some unique malformative lesions.

Significant pathological abnormalities were encountered in a series of 20 temporal lobectomies in children with intractable complex partial seizures. In particular, "dual pathology" (mesial temporal sclerosis with other lesions) was found rather than mesial temporal sclerosis as the only lesion. Unusual pathological findings included capillary penetration of neurons in a neuronal heterotopia in one patient, and foci of extensive cortical disorganization in some cases of mixed tumors and gangliogliomas. A high proportion of neuronal migration disorders was also seen with overlapping pathological features between cortical dysplasia and tuberous sclerosis. In this correlative clinical, radiological, electroencephalographic, and pathological study, some of the pathological lesions in children did not fit the classical categories of neoplasia and malformation and transitional forms were rarely encountered.

Adolescent↗

PubMed1992

Detection and management of gangliogliomas in children.

Forty-two children treated for gangliogliomas were reviewed to identify the best methods of detection and management. Thirty-two of the tumors were supratentorial, four infratentorial, and six were in the spinal cord. Twenty-five patients presented with seizures; the mean duration of symptoms was 5 years in contrast to 1 year in non-seizure patients. Of 31 children studied by computed tomography (CT), calcification in the tumor lesion was found in 19. Magnetic resonance imaging (MRI) showed abnormal high-signal intensity on T2 imaging in six of eight patients. All patients underwent surgical resection and were diagnosed pathologically. Twenty-four patients had total resection, and 14 underwent temporal lobectomies including hippocampectomy. The management of this tumor remains surgical resection without the need for any adjuvant therapy.

Adolescent↗

PubMed1992

Neuroimaging for investigation of seizures in children.

In patients with structural abnormalities of the brain with poor seizure control by medication, epilepsy surgery becomes a very important tool for seizure control. Numerous radiological imaging studies are being used for studying the abnormality in order to aid in the planning of surgery. Included in the radiological imaging modalities are CT, MR, and Xenon CT, SPECT and PET. In future, perfusion and diffusion MR as well as MEG mapping will become part of the investigative tool. The following paper is a summary and discussion of the usefulness of different modalities in different disease entities with a proposal for the method of investigation.

Brain Damage, Chronic↗

PubMed1991

Intracranial germ-cell tumors in children.

All patients with confirmed intracranial germ-cell tumors treated at the Hospital of Sick Children during the period January, 1952, to December, 1989, were reviewed. Of the 51 tumors reviewed, 16 were located in the suprasellar region, 32 in the pineal region, and three in both the pineal and the suprasellar regions. Forty-nine patients underwent surgical resection which was total in seven and partial in 20, and consisted of a biopsy in 22. Two patients were managed on the basis of serum and cerebrospinal fluid markers. Surgical tools such as the operating microscope, the ultrasonic surgical aspirator, and the laser beam allowed safe debulking and removal of the deep-seated tumors in the pineal region. There were no operative deaths in the 36 patients treated since 1972, who included 23 with pineal tumors. Twenty-five patients with germinomas received radiotherapy and had a 5-year survival rate of 85.1%. Thirteen patients with non-germinoma germ-cell tumors received radiotherapy and had a 5-year survival rate of 45.5%. On the basis of this review, the authors recommend resection of pineal and suprasellar germ-cell tumors in order to firmly establish an accurate histological diagnosis to guide the extent of adjuvant therapy. In the case of a pure germinoma without evidence of dissemination, adjuvant therapy consists only of local radiotherapy. On the other hand, for malignant non-germinoma germ-cell tumors, adjuvant therapy must include chemotherapy as well as craniospinal axis radiotherapy.

Adolescent↗

PubMed1990

Normovolaemic induced hypertension therapy for cerebral vasospasm after subarachnoid haemorrhage.

We showed that normovolaemic induced hypertension therapy was effective in reducing ischaemic symptoms attributed to cerebral vasospasm in 41 patients after subarachnoid haemorrhage. By inducing hypertension to 25% to 50% above normal systolic arterial blood pressure, we observed that in 17 of 24 cases (71%) neurological deficits improved. In four cases of haemorrhagic infarction, the blood pressure rose to over 50% of systolic arterial pressure, and a low density area was confirmed on computerized tomography (CT) scan prior to vasospasm. Induced hypertension was therefore not considered when a low density area was revealed on CT scan. Restriction of fluid input is usually a factor in producing hypovolaemia after a neurosurgical operation. Intravascular volume expansion has been reported effective in reversing ischaemic deficits. However, according to Poiseuille's equation, increasing blood volume to a state of hypervolaemia can not enhance flow. The cerebral blood flow (CBF) was raised by increasing perfusion pressure, reducing viscosity, or increasing blood vessel diameter. Intravascular volume expansion elevates not only systemic arterial pressure, but also pulmonary artery wedge pressure over 18 mmHg and cardiac index over 2.2. Since pulmonary oedema and congestive heart failure may develop, one should monitor haemodynamic parameters with the Swan-Ganz catheter as a preventive measure. We emphasize that normovolaemic induced hypertension, maintaining haemodynamics subset 1 of the comparable haemodynamic subsets, is effective in raising perfusion pressure of CBF.

Adult↗

PubMedDate not supplied

Evaluation, surgical approach and outcome of seizure patients with gangliogliomas.

A retrospective study of 15 children with intracranial gangliogliomas and intractable seizures revealed that tumors associated with seizure were located in the temporal and frontal lobes. These patients underwent lobectomy under electrocorticography. Mesial temporal sclerosis was identified in the hippocampus of the excised temporal lobe in 7 of 13 patients with temporal lobectomies. Eleven of the 15 children were seizure-free over a mean follow-up period of 4 years. The surgical approach to gangliogliomas requires careful pre-operative evaluation, including neuroimaging and electrophysiological study to locate seizure activity. Removal of epileptogenic brain as well as the ganglioglioma is recommended to optimize seizure control.

Adolescent↗