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Toshisuke Sakaki

Publications and source records attributed to Toshisuke Sakaki.

59 records · Page 4Linked to original sources
PubMed2002

Color Doppler flow imaging of the superior ophthalmic vein in dural arteriovenous fistulas.

BACKGROUND AND PURPOSE: This article evaluates the intracranial venous hemodynamics of dural arteriovenous fistula (DAVF) on the basis of data from color Doppler flow imaging (CDFI) findings of the superior ophthalmic vein (SOV) and discusses the clinical application of the SOV CDFI to the DAVFs. METHODS: We examined the diameter, flow direction, flow waveform, and flow velocity of the SOV using CDFI in 20 patients with intracranial DAVF. Six patients were asymptomatic; the other 14 patients were symptomatic. Angiographic retrograde cortical venous filling was seen in 14 patients. RESULTS: In the DAVFs, the average SOV diameter was 2.95+/-1.15 mm, which was significantly broad compared with that of the control subjects (P<0.05). The flow direction was reversed in 2 patients and normal in the other 18 patients. Three patients showed an abnormal waveform. A reversed pulsatile waveform was observed in 2 patients, and a normograde pulsatile waveform was seen in 1 patient. The other 17 patients showed normal waveform. The average SOV diameter and resistance index values were significantly higher (P<0.05) in patients with clinical symptoms, angiographic retrograde cortical venous fillings, or large DAVFs compared with those in the other patients. CONCLUSIONS: The SOV CDFI findings in DAVFs correlated well with the patient's clinical symptoms, angiographic findings, and DAVF size. These findings were useful to evaluate the intracranial venous hemodynamics in DAVFs.

Adult↗
PubMed2002

Impairment of autoregulation following cortical venous occlusion in the rat.

Recent experiments showed an upward shift of the lower limit of autoregulation (AR) following photochemical occlusion of cortical veins in the rat. The goal of the present study was to prove the hypothesis that occlusion of cortical veins will be associated with impairment of the upper limit of autoregulation as well. In n = 28 Wistar rats unilateral frontoparietal cranial windows were drilled for transdural assessment of regional cerebral blood flow (rCBF) by laser Doppler scanning. The animals were allotted to two groups: (1) Group A (n = 5), control group for determination of the upper limit of autoregulation with stepwise induced arterial hypertension by intravenous administration of the alpha adrenergic drug methoxamine under continuous monitoring of mean arterial blood pressure (MABP); (2) Group B (n = 23), in which two cortical veins were photochemically occluded with rose bengal dye and fiberoptic illumination upon baseline CBF measurement. This was followed by repeated rCBF measurements under AR testing. Loss of AR in control Group A with passive increase of rCBF occurred at MABP of 147.5 +/- 2.9 mmHg. In Group B venous occlusion was followed by an initial phase of reduced rCBF, and then by pressure passive increases, thereby indicating loss of AR. Statistically significant changes of rCBF when compared to baseline MABP occurred at MABPbaseline + 10% (112.7 +/- 6.6 mmHg). We conclude that AR is impaired upon cortical venous occlusion with the propensity for hyperperfusion injury at a lower level of MABP when compared with a control group. In the context with earlier findings this may lead to narrowing of the corridor for MABP management following intra-operative occlusion of large cortical veins.

Animals↗
PubMed2002

Novel intraoperative cerebral blood flow monitoring by laser-Doppler scanner.

Laser-Doppler (LD) flowmetry was used to measure tissue perfusion non-invasively and continuously during neurosurgical operations using an LD scanner. Scanning was usually completed in 20 seconds. Measurements were processed in software to provide a color-coded image of the tissue perfusion. Moreover, the measurement data, expressed in LD-units, could be used for statistical data analysis. No physical contact was necessary between the scanning device and the exposed brain tissue. The imager provided two-dimensional microvascular flow maps non-invasively and quantitatively during brain operations, and could show the CO2 reactivity in the vessels. LD scanning flowmetry is a promising intraoperative monitoring method for cerebral blood flow changes.

Adult↗
PubMed2002

[Infantile partial seizures due to temporal lesions--analysis of 4 cases].

We studied 4 cases of complex partial seizures due to temporal lesions presenting with benign partial epilepsy in infancy. None of them had neurologic abnormalities. All cases had complex partial seizures, and two had lateralizing signs. All cases had temporal lesions. One of them was detected only by fluid-attenuated inversion recovery (FLAIR) imaging. Histopathologically they were astrocytomas (grade 2 and 3), glio neuronal hamartoma and focal cortical dysplasia. The present cases suggest that patient with infantile complex partial seizures should be carefully followed up, even after the disappearance of seizures, by serial MRI examination including FLAIR imaging and by clinical observation.

Astrocytoma↗