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Biomedical subjects

T Tanikawa

Publications and source records attributed to T Tanikawa.

At least 109 records · Page 6Linked to original sources

Cerebral-evoked responses elicited by direct stimulation of the lateral spinothalamic tract in the human.

The authors recorded cerebral-evoked responses elicited by direct stimulation of the human lateral spinothalamic tract (LST) during percutaneous cordotomy to investigate central conduction of noxious stimuli. These responses consisted of four negative potentials, peak latency being 3.8 (N1), 8.4 (N2), 12.2 (N3) and 21.9 (N4) ms respectively. N1 showed wide distribution over the scalp and was considered to be of subcortical origin. N2-N4 were distributed in both the temporal and central area. The different distribution pattern of N2-N4 from conventional somatosensory-evoked potential suggested a different projection of LST from the medial lemniscus system.

Adult↗

CT-guided stereotactic surgery for evacuation of hypertensive intracerebral hematoma.

During the last 3 years, 46 cases of hypertensive intracerebral hemorrhage were treated by CT-guided stereotactic surgery. Our present report is concerned with the evaluation of this procedure in the treatment of hypertensive intracerebral hematoma, in terms of the rate of aspirated hematoma and follow-up study of patients. It is difficult to draw any definite conclusion about the operative indications. CT-guided stereotactic aspiration, however, can be evaluated as a less invasive and more definitive treatment of intracerebral hematoma in the basal ganglia and thalamus.

Aged↗

[A new apparatus and stereotactic method for percutaneous high cervical cordotomy].

The authors devised a stereotactic apparatus for percutaneous cordotomy based on the experience of 191 percutaneous high cervical cordotomies on 150 patients suffering from intractable pain. This apparatus has two major components. One is a head and neck holder and the other is a guide and marker system. The head and neck holder contains fixed neck holder and head holder which can be movable in vertical direction. Using these holders, the operator can keep the patient's neck in neutral position. The marker system contains two markers of origin and a 10mm scale which indicates center line as well. The guide system, stereotactically designed, is movable in three direction and acrylic guide groove is attached. The guide needle for percutaneous cordotomy is inserted along the guide groove. The guide and marker system can be attached in both sides of the head and neck holder, therefore, the operator can insert the needle in both sides of the patient. This apparatus makes it possible to locate the target stereotactically for percutaneous cordotomy, since location of the inserted needle can be determined with the aid of cervical X-ray, even if there is no image intensifier of TV display screen available. Therefore it can be possible to reduce the X-ray exposure of the patient.

Cordotomy↗

[Evaluation of anticonvulsant-induced bone changes by a microdensitometric method].

The effect of long-term anticonvulsants on bone change was evaluated by microdensitometric method (MD method) in 221 outpatients of Neurological Institute Tokyo Women's Medical College. Laboratory findings including serum Ca, P, Al-p were compared with severity of bone change. Following results were obtained; In 221 patients, 159 cases (72%) were normal, 31 cases (14%) were in the initial stage of abnormality, 23 cases (10%) in grade I, 7 cases (3%) in grade II and one case (1%) in grade III of abnormality. Incidence of abnormality was high in the age of 26-35 years old and in the age over 56 years old. Total dose, serum concentration of diphenylhydantoin (DPH) as well as phenobarbital (PB) and also duration of administration of PB correlated positively with severity of bone change. Duration of administration of DPH and valproic acid (VPA), total dose and serum concentration of VPA did not correlate with severity of bone change. Serum Ca correlated with severity of bone change, but P and Al-p did not correlate with severity of bone change. Pattern of bone change was estimated by two parameters of MD method (MCI and GSmax). Results showed that most of the osteopathy (grade I-III by MD method) fell into osteoporotic type. Based on these results, it is suggested that roentgenologic and biochemical supervision of the patients is required during long-term anticonvulsant therapy.

Absorptiometry, Photon↗

[An assessment of outcome prediction in patients with severe brain damage with auditory brainstem response and blink reflex].

Results of auditory brainstem response (ABR) and electrically elicited blink reflex (BR) recorded from 43 patients with severe brain damage within three days after the onset of illness were analyzed to assess the prognostic value of ABR and BR with respect to patient outcome evaluated by the criteria proposed by Jennett and Bond. It was possible to recognize, in recordings obtained from patients with severe brain damage, three basic patterns of BR as well as five patterns of ABR within three days after the onset. Three basic patterns of BR were composed of Type I, which closely approximated the BR of normal subjects except for moderately prolonged latency of R2, Type II, which indicated absence of bilateral R2 activities, and Type III, which showed absence of R1 as well as bilateral R2. ABRs were graded, in increasing order of abnormality, from Type I to Type V. Type I was almost normal pattern from wave I to wave V. Type II indicated prolonged latency or markedly reduced amplitude of waves IV and V. Type III showed absence of waves IV and V. Type IV had only wave I. Type V indicated absence of all waves. BR abnormalities significantly proved useful in predicting vital prognosis of the comatose patients with supratentorial lesion. In patients who had Type II of BR, additional studies of ABR enhanced the reliability of prediction of functional prognosis. On the other hand, ABR was recognized as stronger basis for predicting outcome in patients with infratentorial lesion. All patients with Type IV or Type V of ABR were expired within one month after the onset.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[The incidence of postoperative epilepsy and prophylactic anticonvulsants in patients with intracranial aneurysm].

The occurrence of epileptic seizures is not rare after craniotomy. The authors examined the incidence of postoperative epilepsy in 150 patients of intracranial aneurysm. Anticonvulsants were given to all patients after operation, but in 12 cases anticonvulsants were discontinued because of liver dysfunction. One hundred and eight out of 138 cases (78%) were prescribed polypharmaceutically, and 30 of 138 cases (22%) were monopharmaceutically. The daily dose of anticonvulsants was as follows; diphenylhydantoin (DPH) was 150-300 mg, phenobarbital (PB) was 50-100 mg, valproic acid (VPA) was 600-1200 mg, and carbamazepin (CBZ) was 200-600 mg. Postoperative epilepsy occurred in 14 of 150 cases (9.3%); 13 cases with anticonvulsants, and 1 case without anticonvulsants. The site of aneurysm was as follows; 6 cases (10.3%) of AC aneurysm, 3 cases (9.7%) of MC aneurysm, 1 case (2.4%) of IC aneurysm, and 4 cases (21.1%) of multiple aneurysm. The interval between operation and epileptic seizure was ranged 2 to 57 months (mean 19.8 months); in 7 cases (50%) within 1 year, and in 13 cases (93%) within 3 years. The authors emphasize that prophylactic use of anticonvulsants is effective to control subclinical epileptic seizures, prescribing anticonvulsants to all patients after craniotomy in general. The medication of anticonvulsants for 3 years would be necessary for avoiding postoperative epileptic seizure.

Adult↗

[Stereotactic metrizamide cervical myelography].

A new apparatus is made for metrizamide cervical myelography. One part of the apparatus is a frame for immobilizing the head and the other is an assembly for guiding spinal needle insertion by lateral puncture. The head frame is made of concave plastic and three rubber discs for immobilizing the forehead and bilateral temporal region. The second piece of apparatus for guiding spinal needle insertion is movable in three directions: up and down, right and left and forward and backward. The sterilized guide made of acrylic is attached. The spinal needle is inserted along the groove of this sterilized guide. The apparatus makes it possible to locate the insertion point easily for the metrizamide cervical myelography by lateral C1-C2 puncture method in prone position, since the location of the tip of the inserted needle can be determined by the aid of lateral cervical x-ray and 10 mm scale, even if image intensifier of TV display screen is not available.

Adult↗

Somatotopic arrangement of lateral spinothalamic tract in percutaneous cervical cordotomy.

As a new clinical approach for the purpose of mapping a lamina analysis, the present report deals with another landmark for insertion of the spinal needle in man other than the usual dentate ligament when performing a percutaneous cordotomy. Electrophysiological studies were made on 19 patients in order to determine the effect of electrostimulation with a bipolar concentric electrode, as well as to corroborate the position of the electrode radiologically. A new apparatus has been devised so that one can locate the target insertion point easily.

Cordotomy↗

Alterations of immunoreactive beta-endorphin in the third ventricular fluid in response to electrical stimulation of the human periaqueductal gray matter.

Immunoreactive beta-endorphin in the third ventricular fluid was measured in response to electrical stimulation of the periaqueductal gray matter in 8 patients with intractable pain during rostral mesencephalic reticulotomy for pain relief. In all patients, marked increase of immunoreactive beta-endorphin was observed. On the other hand, in cases of electrical stimulation of the zona incerta performed during stereoencephalotomy, in 5 patients with involuntary movement, immunoreactive beta-endorphin in the third ventricular fluid did not show any significant change. The authors conclude that the increase of immunoreactive beta-endorphin on electrical stimulation of the periaqueductal gray matter is not a nonspecific response to brain stimulation but a specific response in regard to cerebral localization of endorphins. Direct correlation between pain relief and periaqueductal gray stimulation is also questioned.

Adult↗

[Anatomical identification of horizontal sections on computed tomogram utilizing Schaltenbrand and Bailey's atlas of the human brain (author's transl)].

Difference in angles between horizontal section of Schaltenbrand & Bailey's atlas and horizontal section of CT based on Cantho-Meatal line is only 3.5 to 5.5 degrees. Therefore, the horizontal section of Schaltenbrand & Bailey's atlas can be utilized for analysis of the horizontal section of CT scan, because the basal ganglia are located approximately in the center of the cranial cavity. The lesions at the basal ganglia with superimposing technique utilizing the relation between horizontal section of Schaltenbrand & Bailey's atlas and analogue view of CT can be identified anatomically.

Adult↗