Neurological research
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Neurological research · Oct 1996
Comparative Study Clinical TrialSurgical results and the related topographic anatomy in paraclinoid internal carotid artery aneurysms.
Paraclinoid internal carotid artery aneurysms arising between the roof of the cavernous sinus and the origin of the posterior communicating artery are of considerable interest with regard to their anatomical variations and technical surgical challenges. Twenty-seven patients with 30 paraclinoid aneurysms were treated surgically through pterional intradural approach. Neck clipping was performed in 22 (73%) of the 30 aneurysms, coating in seven, and trapping in one. ⋯ There was one death (4%) due to infarction after unintended carotid artery trapping. The characteristic topographic anatomical features which we considered to pose technical difficulties and to be responsible for the complications or failure in neck clipping were aneurysmal dome extending into the anterior clinoid process, atheroma at the neck, multiple paraclinoid aneurysms, ophthalmic artery originating at the neck, and marked supero-medial shift of the C2 segment of the carotid artery. pre-operative depiction of the topographical anatomy around the paraclinoid aneurysm is essential but not always possible on the basis of conventional angiography. Magnetic resonance or three-dimensional computerized tomographic angiography, and their axial source imaging, were useful in delineating the topography with unusual aneurysmal growth, overlap of aneurysm with the parent artery, and uncommon variations of the surrounding structures.
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Neurological research · Oct 1996
The venous system of the lateral sellar compartment (cavernous sinus): an histological and embryological study.
The microanatomy of the lateral sellar or parasellar venous system (so-called cavernous sinus) is poorly understood and is still passionately debated. The exact nature of this venous structure is not yet clear whether it is a plexus or a sinus. In order to understand the anatomy of this area better, an embryological and adult microanatomical study was performed. ⋯ They differ from true veins. As other dural sinuses, it may contain different types of channels: from simple venous canal to complex venous plexus. The opinions of different authors are reviewed in the introduction and discussed with the results.
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The effects of mild (34 degrees C) and moderate (31 degrees C) hypothermia on the electroencephalogram, cerebral blood flow and outcome from incomplete brain ischemia were compared to normothermia (37 degrees C) in the rat. Rats were anesthetized with fentanyl (25 mu g kg(-1) h(-1)) and 70 percent nitrous oxide in oxygen. Ischemia was produced by right carotid ligation combined with hemorrhagic hypotension to 25 mmHg for 30 min. ⋯ Recovery of cerebral blood flow was not significantly different between the treatment groups. Neurologic and histopathologic outcome were improved in rats receiving moderate hypothermia compared to normothermic controls. These results show that during severe incomplete ischemia, hypothermia has a graded effect on outcome which is consistent with its effects on brain metabolism.
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A series of 62 patients treated surgically for one or several unruptured intracranial aneurysms is reported. 83 aneurysms were treated in 65 operations. The main locations of the aneurysms were: MCA 35%, ICA (posterior communicating) 22%, carotido-ophthalmic segment 12%, carotid bifurcation 11%, anterior communicating artery 11%, verterbro basilar artery 5%. The circumstances of discovery were: incidental 28%, multiple aneurysm 22%, headache 18%, ischemic episode 9%, mass effect 8%, seizures 6%. ⋯ The authors' opinion now is surgical clipping of small and middle-sized aneurysms in young patients, without severe associated pathology, and clearly agreeing with surgery. The limit of age for surgery is usually 65 years except for those aneurysms discovered after a mass-effect. Elderly patients, giant aneurysms, patients with contra-indication for surgery, are proposed for endovascular treatment.
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Although there has been renewed interest in human brain temperature, very little information is available on the association between brain temperature and cerebral perfusion pressure. In this study, we measured brain, tympanic, and rectal temperatures, arterial blood pressure and intracranial pressure in a case of massive hemorrhage deteriorating to brain death, and showed for the first time that when cerebral perfusion pressure began to decrease markedly brain temperature fell rapidly. Rectal and tympanic temperatures were higher than brain temperatures during the period of very low cerebral perfusion pressure. Circadian change in temperature (high at day, low at night) was preserved during the period of brain death.