Neurosurgery
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Case Reports
An extreme lateral approach to intradural lesions of the cervical spine and foramen magnum.
Meningiomas and neurofibromas are the most common intradural extramedullary tumors of the foramen magnum and cervical spine. Many of these tumors are located ventral or ventrolateral to the spinal cord and medulla. Posterior approaches, although adequate for the management of most of these tumors, can sometimes result in incomplete removal of the tumor and exacerbation of the neurological deficits. ⋯ The entire longitudinal and lateral extent of the tumor and also its extradural extension can be can be managed by this approach. This approach can be considered in such a group of patients harboring entirely ventral or recurrent tumors for which the conventional posterior approach has failed. Six patients who underwent this procedure are described to illustrate its application.
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The cerebrovascular response to CO2 was evaluated by measuring relative changes in blood flow velocity within the middle cerebral artery by transcranial Doppler ultrasonography during normo-, hypo-, and hypercapnia. In seven patients without subarachnoid hemorrhage (five with unruptured arteriovenous malformations and two with aneurysms), the CO2 vasoreactivity was tested on the side of the middle cerebral artery with normal flow velocities opposite the lesion. A baseline CO2 reactivity test was obtained in each patient and then repeated under constant intravenous infusion of nimodipine, 2 mg/hr. ⋯ Two months later, after full recovery from the subarachnoid hemorrhage and normalization of the velocities, a third measurement of CO2 reactivity was obtained as a baseline control. No significant effect of nimodipine on CO2 vasoreactivity could be demonstrated in any of the test periods. In the second week after a subarachnoid hemorrhage, a significant reduction of the cerebrovascular response to CO2 was found (P less than 0.005).
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A new electrode design for the extradural recording of electrical brain activity is described. Epidural peg electrodes are implantable mushroom-shaped composites of Silastic elastomer and a stainless steel or platinum disc. ⋯ They are also used for canvassing wide areas of cortex to determine whether a seizure is focal in origin, arises diffusely from a hemisphere, or has a bilateral origin. Advantages of epidural peg electrodes over screw and other types of epidural electrodes include low risk of infection or hemorrhage and improved patient comfort.
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One aneurysm of the basilar artery and three large, paraclinoid aneurysms of the internal carotid artery (ICA) were treated with the aid of intraoperative temporary balloon occlusion of the vessel. Optimal clip placement was confirmed using intraoperative angiography. This technique provided excellent proximal vascular control and for the large aneurysms of the paraclinoid ICA obviated the need for surgical exposure of the ICA in the neck. We think this is a useful adjunct in the surgical management of aneurysms of both the basilar artery and proximal ICA.
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Thirty-five patients were admitted to the hospital with Glasgow coma scale scores of 4 to 7 after severe, blunt head injury. Blood flow velocities of the middle cerebral artery (MCA) and the ipsilateral internal carotid artery (ICA), high in the neck, were recorded noninvasively by Doppler ultrasonography. Serial examinations were begun within 48 hours of trauma and continued until the patient either died or was discharged. ⋯ There was a significant correlation between the occurrence of vasospasm and the quantity of cisternal or intracerebral blood seen on a computed tomographic scan. No correlation was found with the age of the patients, the Glasgow coma scale score at admission, the intracranial pressure, or the functional outcome 6 months after injury. The occurrence of a secondary infarction in a patient with severe MCA spasm suggests that, at least in some cases, spasm may influence the prognosis.