K Hayasaki

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The contribution of brain edema to brain swelling in cases of traumatic brain injury remains a critical problem. The authors believe that cellular edema, the result of complex neurotoxic events, is the major contributor to brain swelling and that vasogenic edema, secondary to blood-brain barrier compromise, may be overemphasized. The objective of this(More)
The contribution of blood brain barrier opening to traumatic brain edema is not known. This study compares the course of traumatic BBB disruption and edema formation, with the hypothesis that they are not obligately related. Sprague-Dawley rats were divided into three groups: Group A (n = 47)--Impact Acceleration (IAM); Group B (n = 104)--lateral cortical(More)
The objective of this study was to quantify the temporal water content changes and document the type of edema (cellular versus vasogenic) that is occurring during both the acute and the late stages of edema development following closed head injury. Adult Sprague rats (n = 50) were separated into two groups: Group I: Sham (n = 8), Group II: Trauma (n = 42).(More)
We hypothesized, that with atrophy, the correlation between water content and specific gravity of brain solids would break down signifying the onset of the atrophic process. The correlation between tissue water content, specific gravity of solids and ventricular size was studied in an impact acceleration model of closed head injury of the rat. Adult Sprague(More)
Management of cerebral perfusion pressure (CPP) is thought to be important for the treatment of traumatic brain injury (TBI). Vasopressors have been advocated as a method of increasing mean arterial blood pressure (mABP) and cerebral perfusion pressure (CPP) in the face of rising intracranial pressure (ICP). There are unresolved issues and theoretical risks(More)
The risk of vasopressors worsening cerebral edema has been raised. Previously we have reported that dopamine was able to restore cerebral blood flow in a model of monotonically rising intracranial pressure. In this study the effects of dopamine on cortical contusion and diffuse injury with secondary insult are examined. Adult male rats were divided into two(More)
We treated three cases of inflammatory granulomas extending from the sphenoid sinus to the cavernous sinus. Case 1 was that of a 36-year-old male with diplopia and right ptosis. Case 2 was that of a 40-year-old male with frontal headache. Case 3 was that of a 70-year-old female with left impaired vision and frontal headache. In the first case, MRI(More)
A case of persistent primitive hypoglossal artery (PPHA) associated with arteriovenous malformation (AVM) is reported. A 46-year-old male suddenly developed severe headache followed by transient unconsciousness and was admitted to our hospital 2 hours later. A computed tomographic scan showed subarachnoid hemorrhage. Angiograms revealed an AVM in the left(More)
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