Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Jan 2003
Evaluation of the safety of recent surgical microscopes equipped with xenon light sources.
Although recent surgical microscopes for neurosurgery are equipped with xenon light sources to obtain bright fields of vision, the safety of a xenon beam, which has strong energy intensity in a long ultraviolet light, for cortical neurons has not been evaluated. Cranial windows were made in the parietal bones of gerbils. The skull of each gerbil was covered with warmed saline (0.5 mm in depth) to maintain the brain temperature. ⋯ Because the highest energy levels of 365-nm ultraviolet rays emitted from surgical microscopes measured in the present study (0.379 mwatts/cm (2)) were much closer to the dose causing 0% damage than to the dose causing 9% damage, the risk of neuronal injury occurring during microsurgery could be negligible. However, care should be taken in patients who take medicine classified as photosensitizing agents, such as diphenylhydantoin, which are thought to concentrate ultraviolet energy. The use of saline over the cortical surface may be beneficial for reducing the detrimental effects of 365-nm ultraviolet light.
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J Neurosurg Anesthesiol · Oct 2002
Case ReportsCerebral injury predicted by transcranial Doppler ultrasonography but not electroencephalography during carotid endarterectomy.
When shunts are selectively used during carotid endarterectomy, the adequacy of collateral cerebral blood flow (CBF) after the carotid artery is clamped is determined by monitors based on different physiologic measurements. In this series of three patients, we used electroencephalography (EEG) to measure neuronal electrical activity and transcranial Doppler ultrasonography (TCD) to measure CBF velocity. In each of our cases, the EEG was unchanged from preclamp values, while TCD CBF velocity was dramatically reduced. All three patients had transient neuropsychometric or neurologic changes after surgery, which resolved.
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J Neurosurg Anesthesiol · Oct 2002
Clinical TrialThe low normothermia concept--maintaining a core body temperature between 36 and 37 degrees C in acute stroke unit patients.
Elevated body temperature increases mortality and worsens outcome in acute stroke patients. In animal models of stroke, even slight hypothermia was shown to be neuroprotective. Pharmacological treatment alone (paracetamol, metamizol) usually fails to lower core body temperature below 37 degrees C. ⋯ Continuous body core temperature reduction of 1-2 degrees C may safely be attained by a cooling mattress in nonventilated stroke unit patients. Critically high temperature values can be avoided. The neuroprotective potential of this method has to be assessed in a controlled trial.
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A rare case of intracerebral hematoma after spinal anesthesia is reported along with a review of the literature. The patient demonstrated a remarkable recovery after a timely diagnosis and surgical evacuation.
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Infrared pupillary scans have been used extensively as an objective measure of pupillary reflexes during pharmacological studies of human subjects, but no previous scans have documented the pupillary changes during transtentorial uncal herniation. We present infrared pupillary scans from three patients with brain stem compression secondary to expanding intracranial mass lesions. The scans were made with a portable device permitting infrared pupillometry at the patient's bedside. Portable infrared pupillometry records objective measurements of pupillary light reflexes, which provides information useful for diagnosing transtentorial herniation and affords objective measurements of an important endpoint in the management of patients with head trauma or supratentorial mass lesions.