摘要:

&NA;The authors studied 10 cats to assess the question of abolition of cerebral autoregulation attendant on the use of nitroprusside for hypotensive anesthesia. After the establishment of stable base line parameters, a continuous infusion of sodium nitroprusside was begun in a dose sufficient to maintain a mean systemic arterial pressure of 65 mm Hg. Infusion was continued for incremental periods of 30 seconds to 10 minutes, increasing the time of infusion by 30 seconds after each subsequent trial. At 10 seconds after the cessation of nitroprusside administration, intravenous dopamine was infused to raise the systemic arterial pressure to a mean of 100 mm Hg, and the subsequent response in intracranial pressure was recorded in each instance. In no animal was a loss of cerebral autoregulation noted when the nitroprusside infusion was maintained for 3 minutes or less. When the infusion was maintained for 4 minutes or longer, cerebral autoregulation was lost in each animal, and the length of time to return of cerebral autoregulation correlated with the duration of nitroprusside infusion. Sodium nitroprusside disturbs the integrity of cerebral pressure autoregulation, and the onset and extent of this disturbance is a dose‐dependent phenomenon.

ISSN:0148-396X    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

&NA;A recent experience with a chronic extradural hematoma found unexpectedly during an evaluation for an enlarged sella turcica is reported. This case, as well as pertinent literature, demonstrates the variability of the classical signs in the chronic lesion. Our experience suggests that the diagnosis of patients with persistent symptoms after head injury may be clarified by computerized tomographic scanning, which in the present case revealed chronic extradural hematoma.

ISSN:0148-396X    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

&NA;Symptomatic Rathke's cleft cysts are uncommon. We present a case with suprasellar extension manifested by hypopituitarism and visual disturbances. The treatment was trans‐sphenoidal evacuation and partial removal of the capsule. We suggest that the trans‐sphenoidal approach to these lesions is usually adequate and that radical removal of the capsule is not necessary.

ISSN:0148-396X    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

&NA;Two cases of solitary neurogenic tumors of the brachial plexus unassociated with von Recklinghausen's disease are presented. One patient had a malignant schwannoma. The lesion of the other patient was benign and was diagnosed pathologically as a plexiform neurofibroma. These uncommon neurogenic tumors of the brachial plexus unassociated with von Recklinghausen's disease pose diagnostic and surgical problems. The initial clinical presentation is usually that of a painless supraclavicular mass. At the time of surgical exploration, the exact site or nerve of origin cannot always be identified. If motor loss is caused by such a tumor of the brachial plexus, it usually indicates a malignant lesion and a poor prognosis. Although wide radical excision of a malignant neurogenic tumor is indicated surgically, one of our patients had an early malignant recurrence that necessitated immediate amputation.

ISSN:0148-396X    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

&NA;This report describes a new accessory fiberoptic light for the most widely used surgical microscope. The advantages of this light are that it permits easy sterile draping of the microscope, does not require a special lens cover, can be adjusted to vary the size and location of the field of illumination, and produces minimal interference with the passage of microinstruments into the operative exposure.

ISSN:0148-396X    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

&NA;Probability theory asserts the lawfulness of seemingly random events in large populations and seems to be a reasonable approach to a general understanding of the structure and function of the nervous system. The brain, by virtue of the number of its components, the multiplicity of their possible interconnections, and the range and rapidity of their outputs, is almost implausably complex in its over‐all design. Probability theory, therefore, is usually applied to (a) descriptions of the behavior of large neuronal populations, (b) statistical analysis of neuronal spike trains, and (c) theoretical models of neuronal interaction. A consideration of each of these subjects is presented, as is a discussion of the most fundamental level of application of the theory to the nervous system: (d) the assertion that the neuron and/or brain is inherently nondeterministic. In practical terms this is shown to be a “nonissue;” the uncertainty principle that follows has rather definite philosophical implications.

ISSN:0148-396X    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

&NA;Problem: A 72‐year‐old widow in otherwise excellent health is plagued by incapacitating trigeminal neuralgia involving the right 2nd and 3rd divisions. She has not responded to large doses of carbamazepine and sodium phenytoin, and you have determined that further medical therapy will be fruitless. What surgical procedure would you select, what is your morbidity and mortality, and what results can you expect?

ISSN:0148-396X    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0148-396X    

出版商:OVID    

年代:1979

数据来源: OVID