✓ Several techniques have been employed to incise the temporalis muscle for the pterional craniotomy. The authors describe a method which provides the advantage of a free bone flap, yet allows anatomical reapproximation of the temporalis muscle to its bone attachment.
Robert F. Spetzler and K. Stuart Lee
K. Stuart Lee and David L. Kelly Jr.
✓ The case of a patient with Cushing's disease and a pituitary macroadenoma, who also had a persistent trigeminal artery coursing through the sella turcica on preoperative imaging studies, is presented. The patient was treated by transsphenoidal resection of the tumor.
K. Stuart Lee, Courtland H. Davis Jr. and Joe M. McWhorter
✓ Various anesthetic and surgical techniques have been recommended with or without cerebral function monitoring in attempts to reduce the risk of carotid endarterectomy, but there is no consensus as to the ideal method for performing this procedure. General anesthesia is now the most common anesthetic technique used, but of 337 carotid endarterectomies performed by the authors' service from 1981 through 1985, 305 (91%) were conducted with regional anesthesia. This paper presents the morbidity and mortality rates for those patients. There were two perioperative transient ischemic attacks (0.66%), two perioperative strokes (0.66%), and two perioperative deaths (0.66%). No patient in the series suffered a myocardial infarction within 30 days after endarterectomy. This series demonstrates that carotid endarterectomy can be performed with good results using regional anesthesia, which facilitates intraoperative cerebral function monitoring. Regional anesthesia is associated with a very low incidence of postoperative hypertension and perioperative myocardial infarction.
K. Stuart Lee, David J. Gower, Joe M. McWhorter and David A. Albertson
✓ Anterior sacral meningoceles are rare. This report describes familial anterior sacral meningoceles in a father and daughter who underwent magnetic resonance imaging as part of the preoperative evaluation. Magnetic resonance imaging showed a pelvic teratoma in the daughter and confirmed the absence of abnormal tissue in the father — findings not clearly provided by ultrasound studies, myelography, or contrast-enhanced computerized tomography. It is believed that MR imaging is the most useful preoperative diagnostic technique available in establishing a treatment plan for anterior sacral meningocele.
David J. Gower, Carol Hollman, K. Stuart Lee and Michael Tytell
✓ The heat shock or stress response is a highly conserved primary cellular response to injury. Synthesis of stress proteins (also called “heat shock proteins”) is an integral component of this response. Protection from various forms of sublethal stress following increased production of stress proteins has been demonstrated in a number of systems, including the retina. This immunocytochemical study demonstrates the synthesis, accumulation, and redistribution of the 70-kD stress protein following spinal cord injury in rats. The observations confirm that stress protein production is a fundamental feature of the molecular response of the spinal cord to injury, and raise the possibility that augmentation of this response could enhance posttraumatic neuronal survival.
David J. Gower, Carol Hollman, K. Stuart Lee and Michael Tytell
✓ Due to its investiture with bone, the spinal cord can be difficult to study anatomically and histologically. Tissue degradation during immersion fixation or mechanical trauma during extraction of unfixed tissue often produces confusing artifacts. Perfusion fixation eliminates many of these problems, but it is a slow, tedious, and technically demanding procedure. This report demonstrates that microwave irradiation of the spinal cord before its removal from the spine is a rapid and easy method of tissue fixation with an absence of artifacts comparable to that with perfusion fixation.
Report of two cases
K. Stuart Lee, Jean N. Angelo, Joe M. McWhorter and Courtland H. Davis Jr
✓ Subependymomas are relatively unusual tumors with a distinctive histological appearance. They are generally considered to be benign, and they are often found incidentally at autopsy. Most are located intracranially, and the most common site of origin is the fourth ventricle. Only two cases of subependymoma of the spinal cord have been reported previously. The authors present two additional cases of subependymoma of the cervical cord; both were symptomatic, and both were treated by microsurgical removal.
Richard S. Zimmerman, Robert F. Spetzler, K. Stuart Lee, Joseph M. Zabramski and Ronald W. Hargraves
✓ Once they become symptomatic, cavernous malformations of the brain stem appear to cause progressive morbidity from repetitive hemorrhage, and can even be fatal. Twenty-four patients with long-tract and/or cranial nerve findings from their cavernous malformations of the brain stem were seen for initial evaluation or surgical consultation and thereafter received either surgical or continued conservative treatment. The decision to operate was based on the proximity of the cavernous malformation to the pial surface of the brain stem, the patient's neurological status, and the number of symptomatic episodes. Sixteen patients were treated by definitive surgery directed at excision of their malformation. In four patients, associated venous malformations influenced the surgical approach and their recognition avoided the risk of inappropriate excision of the venous malformation. Although some of the 16 patients had transient, immediate, postoperative worsening of their neurological deficits, the outcome of all except one was the same or improved. Only one patient developed recurrent symptoms: a new deficit 2½ years after surgery required reoperation after regrowth of the cavernous malformation. She has been neurologically stable since the second surgery. One patient died 6 months postoperatively from a shunt infection and sepsis. The eight conservatively treated patients are followed with annual magnetic resonance imaging studies. One has a dramatic associated venous malformation. Seven patients have either minor intermittent or no symptoms, and the eighth died from a hemorrhage 1 year after his initial presentation.
Based on these results, surgical extirpation of symptomatic cavernous malformations of the brain stem appears to be the treatment of choice when a patient is symptomatic, the lesion is located superficially, and an operative approach can spare eloquent tissue. When cavernous malformations of the brain stem are completely excised, cure appears permanent.
Joseph M. Zabramski, Robert F. Spetzler, K. Stuart Lee, Stephen M. Papadopoulos, Edwin Bovill, Richard S. Zimmerman and Joshua B. Bederson
✓ Recent laboratory studies have demonstrated that intracisternal administration of recombinant tissue plasminogen activator (rt-PA) can facilitate the normal clearing of blood from the subarachnoid space and prevent or ameliorate delayed arterial spasm. The results of a preliminary Phase I trial of intracisternal rt-PA in 10 patients are reported with documented aneurysmal subarachnoid hemorrhage (SAH). All patients enrolled were classified as clinical Grade III or IV (according to Hunt and Hess) with thick clots or layers of blood in the basal cisterns and major cerebral fissures (Fisher Grade 3). Ventriculostomy and surgery for clipping of the aneurysms were performed within 48 hours of hemorrhage. In one patient, 10 mg rt-PA was instilled into the subarachnoid cisterns prior to closing the dura. In the remaining nine patients, a small silicone catheter was left in the subarachnoid space and rt-PA (5 mg in four cases or 1.5 mg (0.5 mg every 8 hours for three infusions) in five cases) was instilled 12 to 24 hours after surgery. Minor local bleeding complications were noted in all patients receiving 5 or 10 mg rt-PA. Oozing was noted at the operative incision site in four of five patients and at the ventriculostomy site in two patients. One patient developed a small epidural hematoma that was treated by delayed drainage. No bleeding complications were noted in the patients receiving the lower regimen of rt-PA (three infusions of 0.5 mg each). Serial coagulation studies demonstrated no evidence of systemic fibrinolysis. Analysis of cisternal cerebrospinal fluid samples revealed thrombolytic tissue plasminogen activator (t-PA) levels for 24 to 48 hours. Follow-up cerebral angiography 7 to 8 days after rupture disclosed mild to moderate spasm in nine patients, while one patient with hemorrhage from a posterior inferior cerebellar artery aneurysm had severe focal spasm of the vertebral arteries that was not symptomatic. These results suggest that postoperative treatment with rt-PA may be effective in reducing the severity of delayed cerebral vasospasm. The results of serial t-PA levels suggest that the lower dosage regimen with divided dosages at 8-hour intervals is well tolerated and that even lower dosages may be effective. Further studies are clearly indicated.