Intracranial chondroma arising from the cranial vault: CT and MR appearance.

A case of intracranial chondroma arising from the right parietal bone in a 37-year-old woman is presented. CT and MRI findings as well as the differential diagnosis of the lesion are discussed.

Prospective surveillance for perioperative venous thrombosis. Experience in 2643 patients.

BACKGROUND: Patients who undergo neurosurgical procedures are at high risk for perioperative deep vein thrombosis (DVT) and pulmonary embolism (PE), which have been reported in 6% to 43% of these patients. OBJECTIVES: To (1) determine the utility of prospective DVT surveillance in patients who undergo neurosurgical procedures by using venous duplex ultrasound scanning (VDUS), (2) assess the efficacy of DVT prophylaxis (elastic stockings and intermittent pneumatic compression), (3) identify subgroups of patients who are at higher risk, and (4) determine whether DVT surveillance would reduce the incidence of fatal PE. DESIGN: All patients had undergone preoperative VDUS of both lower extremities, and postoperative VDUS was performed on days 3 and 7, and weekly thereafter until patients were ambulatory or discharged. PATIENTS: During a 5-year period, 2643 patients who underwent neurosurgical procedures were enrolled in prospective DVT surveillance. SETTING: University-affiliated community hospital. RESULTS: Acute DVT was diagnosed in 147 (5.6%) of the 2643 patients. Eighty-one percent of the patients with acute DVT were asymptomatic at the time of diagnosis. Deep vein thrombosis developed de novo in the proximal veins in 98% of the patients. Patients in whom a craniotomy was done had a significantly higher risk for DVT (7.7%, P = .006), and patients who underwent cervical or lumbar spinal surgical procedures had a significantly lower risk (1.5%, P < .001). Among those patients in whom a craniotomy was performed for treatment of a tumor and who had DVT, 87% had malignant neoplasms. Significant lower-extremity neuromotor dysfunction was present in 69% of all patients with DVT, and this finding predominated among patients with DVT in the subgroups with a lower risk. A PE was diagnosed in 5 patients (0.19%) while they were hospitalized, and a PE was fatal in 2 (0.07% of all patients). CONCLUSIONS: Most perioperative DVTs were clinically silent and formed spontaneously in proximal venous segments where there would be a risk for a PE. The overall incidence of DVT (5.6%) was low, suggesting effective DVT prophylaxis. Patients who underwent spinal surgical procedures were at a significantly lower risk for DVT, and future surveillance is not indicated in this patient group unless other conditions exist (paralysis, malignancy). Patients in whom a craniotomy was performed had a significantly higher risk of DVT, particularly when other risk factors existed. The low incidence of a fatal PE (0.07%) reflected that early detection and treatment of proximal DVT were facilitated by prospective VDUS surveillance in these patients.

The preservation of hearing and facial nerve function in a consecutive series of unilateral vestibular nerve schwannoma surgical patients (acoustic neuroma).

Between January 1981 and February 1992, 102 non-NF-2 patients underwent removal of a unilateral vesitbular schwannoma. There were 54 women and 48 men. Eighty-six percent of patients with normal facial function preoperatively retained normal function (House score 1 or 2) postoperatively. Of the 64 patients with a functional cochlear nerve preoperatively, five had normal hearing (PTA < 25 dB, SB > 70%), five had near normal hearing (PTA < 45 dB, SD > 70%), four patients had preserved hearing (PTA < 50 dB, SD > 50%), and three patients had preserved cochlear nerve function (PTA > 50 dB, SD < 50%) after surgery. Hearing preservation was obtained in patients whose tumors were larger than 3 cm. Radiological follow-up revealed 10 patients with recurrent tumor, all but one asymptomatic.

The transnasal approach to advanced lesions of the sphenoid sinus and pituitary.

The techniques of transseptal transsphenoidal hypophysectomy are discussed in detail in this article. The span of disease that may be treated by this method in addition to the need for a team approach of otolaryngologists and neurosurgeons is illustrated with several pertinent case reports.

Management of athletic injuries of the cervical spine and spinal cord.

Injuries to the cervical spine among athletes present inherent difficulties, especially in advising for return to contact sports. Experience with the acute care of 63 patients who sustained cervical spine injuries while participating in organized sporting events is analyzed. Forty-five patients had permanent injury to the vertebral column and/or spinal cord, while 18 suffered only transient spinal cord symptoms. Football mishaps accounted for the highest number of injuries, followed by wrestling and gymnastics. Twelve patients had complete spinal cord injury, 14 patients had incomplete spinal cord injury, and 19 patients had injury to the vertebral column alone. The majority of the spinal cord lesions occurred at the C4 and C5 levels, while bony injuries of C4 through C6 predominated. Twenty-five patients required surgical stabilization, and 20 were treated with orthosis only. There was no instance of associated systemic injuries, and hospital complications were few. The mean time of hospitalization was 19.1 days for injured patients and 3.0 days for patients with transient symptoms. A classification was developed to assist in the management of these patients: Type 1 athletic injuries to the cervical spine are those that cause neurological injury; patients with Type 1 injuries are not allowed to participate in contact, competitive sporting events. Type 2 injuries consist of transient neurological deficits without radiological evidence of abnormalities; these injuries usually do not prohibit further participation in contact sports unless they become repetitive. Type 3 injuries are those that cause radiological abnormality alone; these represent a heterogeneous group.(ABSTRACT TRUNCATED AT 250 WORDS)

Diving injuries of the cervical spine.

From 1975 to 1986, 2435 patients were admitted to the Northwestern University-Midwest Regional Spinal Cord Injury Unit. Of these, 220 patients (9.0%) had documented neck fractures from diving accidents, representing the largest series of acute diving injuries yet analyzed. The average age of these patients was 21 years, and males predominated. Two hundred twelve patients (96.4%) were admitted within 48 hours of injury. Associated injuries were rare: none had intracranial mass lesions or systemic injuries, and only nine were near-drowning victims who required endotracheal intubation. The most common levels of injury were C-5 (140 fractures) and C-6 (85 fractures), with 70 patients having fractures at more than one level. Neurological injury was sustained in 154 (70.0%) patients, while 66 (30.0%) patients were neurologically intact. One hundred forty-seven (66.8%) patients underwent posterior cervical fusion, and anterior fusion was performed in 36 (16.4%), allowing for early ambulation and an average hospital stay of 17 days. Hospitalization was relatively uncomplicated, with urinary tract infection in 121 (55.0%), pneumonia in nine (4.1%), and deep vein thrombosis in 24 (10.9%). Long-term follow up averaged 5 years and was obtained in 160 (72.7%) patients. Sixteen (10.0%) improved neurologically, five (3.1%) deteriorated, and 139 (86.9%) were unchanged. Notably, this large study shows that diving accidents occur in a young, healthy population who sustain essentially no other associated intracranial or systemic injuries and have few serious hospital complications. Such patients may be mobilized early in their care after either internal or external stabilization. Subsequent long-term neurological improvement can be expected to occur in about 10% of patients. The importance of water safety and injury prevention is stressed.

Duplex venous scanning for the prospective surveillance of perioperative venous thrombosis.

A total of 361 patients undergoing a variety of major neurosurgical procedures were entered into a prospective surveillance program using duplex ultrasound scanning for detection of perioperative deep venous thrombosis (DVT). All patients had duplex scans of the major veins of both legs preoperatively, on the third and seventh postoperative days, and at weekly intervals thereafter if hospitalized. All patients received elastic stocking and intermittent mechanical calf compression. Perioperative DVT was diagnosed by duplex scan in 17 cases (4.7%); 2 cases were present preoperatively and the remaining 15 cases developed after surgery. Venography detected only one false-positive scan in this series. One patient with DVT died, but the postmortem examination revealed no pulmonary embolism. The results of serial venous scans were normal in 344 cases. There were no in-hospital pulmonary embolisms in any patient with normal venous scan results. Two patients (0.6%) with normal serial scan results had fatal pulmonary embolism 1 and 3 weeks after discharge. Duplex venous scanning was useful for prospective DVT surveillance of a high-risk group. The overall incidence of DVT (4.7%) is below that expected in such patients, suggesting the effectiveness of the program of prophylaxis. Scan results were reliable for therapeutic decisions and did not jeopardize patient safety.

Castleman's disease manifesting in the central nervous system: case report with immunological studies.

Castleman's disease is an uncommon lymphoproliferative disorder that manifests itself as a local or generalized tumor-like condition affecting both lymph nodes and nonnodal tissues, usually in the chest or abdomen. Only two prior examples involving the central nervous system had been reported when this patient was encountered. Very recently, three additional cases have been reported by Severson et al. We report the sixth case of Castleman's disease affecting the central nervous system, which occurred in a 63-year-old woman in whom the diagnosis was made after craniotomy for a mass lesion involving the dura over the frontal regions. Neuroradiological, clinical, and immunopathological characteristics of the case are presented. The lesion was treated with cranial irradiation and the patient is alive and symptom free three years after initial treatment.

Pediatric spinal injury: the very young.

Maturity of the spine and spine-supporting structures is an important variable distinguishing spinal cord injuries in children from those in adults. Clinical data are presented from 71 children aged 12 years or younger who constituted 2.7% of 2598 spinal cord-injured patients admitted to the authors' institutions from June, 1972, to June, 1986. The 47 children with traumatic spinal cord injury averaged 6.9 years of age and included 20 girls (43%). The etiology of the pediatric injuries differed from that of adult injuries in that falls were the most common causative factor (38%) followed by automobile-related injuries (20%). Ten children (21.3%) had spinal cord injury without radiographic abnormality (SCIWORA), whereas 27 (57%) had evidence of neurological injury. Complete neurological injury was seen in 19% of all traumatic pediatric spinal cord injuries and in 40% of those with SCIWORA. The most frequent level of spinal injury was C-2 (27%, 15 cases) followed by T-10 (13%, seven cases). Upon statistical examination of the data, a subpopulation of children aged 3 years or younger emerged. These very young children had a significant difference in level of injury, requirement for surgical stability, and sex distribution compared to 4- to 12-year-old children.

The effects of intravenous prostacyclin in a model of microsurgical thrombosis.

Numerous agents have been administered in an attempt to achieve specific biochemical antiplatelet activity. A model of microsurgical trauma was utilized to create a nonocclusive thrombus, similar to what occurs in the postoperative period. Prostacyclin (PGI2) was given in a high intravenous dose which caused in vitro inhibition of platelet aggregation in rats and rabbits. Although hematological and cardiovascular side effects of PGI2 were tolerated, in vivo platelet thrombus formation persisted and constituted 25-75% of the postoperative thrombus. Even though platelets were inhibited by PGI2, other significant stimuli remained at the site of injury for activation and participation of platelets in the formation of a thrombus.

Laser-sealed arteriotomy: a reliable aneurysm model.

Laser-assisted vascular anastomosis (LAVA) is associated with a significant aneurysm problem when it is applied to small arteries. The etiology of this phenomenon was investigated by creating arteriotomies of different lengths and orientation in the rat carotid artery and sealing them with the milliwatt CO2 laser. It was found that increasing the arteriotomy length from 0.5 to 1.0 mm significantly raised aneurysm occurrence (4/17 vs. 25/28, chi-square: p less than 0.001) regardless of orientation. Systemic hypertension (systolic blood pressure greater than or equal to 170 mm Hg) also significantly affected the aneurysm rate among the 0.5-mm arteriotomy group, raising aneurysm occurrence from 23.5% (4/17) to 100% (14/14) (p less than 0.001). Assuming that the stay-sutures used for LAVA's act as rigid supports, the rate of aneurysm occurrence must be related to the distance between sutures. This phenomenon has been exploited to create a reliable aneurysm model.

Bursting pressure of experimental aneurysms.

The laser-sealed arteriotomy (LSA) technique was used to create experimental aneurysms in the rat carotid artery. Animals were reexplored 2, 4, and 8 weeks following LSA, at which time the aneurysms were measured and subjected to a bursting strength pressure. In addition, a group of hypertensive rats with LSA was also tested 2 weeks after surgery. The LSA procedure produced aneurysms of a stable size and bursting pressure over the time studied. The bursting pressure technique may be applicable for assessing aneurysm therapy in an experimental setting.

Laser-assisted end-to-side anastomosis.

The milliwatt CO2 laser was used to anastomose rat carotid arteries in an end-to-side fashion, and this technique was compared to the standard suture technique. Vessels were studied at two to six weeks. All anastomosis were patient and overall, there was a 78.6 percent rate of aneurysm formation in the laser cohort, compared with 7.1 percent with suture (p less than 0.001 Fisher exact). Vessels and aneurysm histology were similar to those previously reported for the end-to-end technique.

Review of tissue welding applications in neurosurgery.

New technical advances have made feasible the utilization of low-powered laser energy for constructive applications. Experience with laser bonding of blood vessels, peripheral nerves, and dura has been obtained. These studies are summarized, and the future potential of laser bonding of tissues of the central nervous system is discussed.

Acoustic nerve tumor surgery before and since the laser: comparison of results.

A random computer selection of 21 patients who underwent 28 operations for acoustic neurinoma between 1974 and 1980 using conventional methods, including the operating microscope and microtechnique, was compared with a cohort of 22 patients who underwent 25 operations between 1980 and 1984 utilizing a carbon dioxide laser. Completeness of tumor removal, anatomical and functional preservation of the facial nerve, preservation of hearing, morbidity and mortality, average hospital stay, and eventual outcome were used as markers and were compared. Utilizing P values, the study demonstrated a significantly superior outcome, and as a result a better life quality, in patients who were operated on utilizing a CO2 laser in addition to conventional microsurgical technique.

Comparison of myointimal hyperplasia in laser-assisted and suture anastomosed arteries. A preliminary report.

Use of the milliwatt CO2 laser to perform microvascular anastomoses is associated with characteristic histologic changes, including intimal hyperplasia and medial necrosis. The extent of myointimal proliferation after both suture and laser-assisted vascular anastomosis was assessed in the rat femoral artery model. At 2 weeks the average intimal height of the laser-anastomosed vessels was 11.7 +/- 2.2 microns (mean +/- standard error of the mean) vs. 21.3 +/- 3.2 microns for sutured arteries (p less than 0.05). By 6 weeks the groups were equivalent (laser, 25.6 +/- 4.6 microns; suture, 17.3 +/- 1.2 microns; p, not significant). The medial changes associated with the laser-assisted method appear to inhibit the proliferative response at 2 weeks but are reversed by 6 weeks.

Aneurysm formation after low power carbon dioxide laser-assisted vascular anastomosis.

A series of 125 adult rats was operated upon to perform end-to-end anastomosis of the femoral artery using either a carbon dioxide laser or conventional suture technique. Vessels were inspected at varying time intervals grossly and microscopically. Overall, the rate of aneurysm formation for the laser group was 18.6% (21/113). Late aneurysm formation (1 week or longer after operation) was seen in 29.8% (20/67) of the laser group. No aneurysms were noted in the suture group either early or late. Histological examination of the laser-joined vessels revealed widespread necrosis and loss of elastic elements in the media. In time, abnormal spindle-shaped cells appeared in this damaged layer. Histologically, the aneurysms were indistinguishable from those reported in human cerebral aneurysm cases. This technique provides an experimental aneurysm model and lends support to the acquired/degenerative theory of human cerebral aneurysm formation.

Pneumocephalus in patients with CSF shunts.

The authors present two cases of pneumocephalus occurring in patients with permanent shunts and review nine previously reported cases. Mental status changes and headache are the most common presenting symptoms. Six of the 11 cases of pneumocephalus occurred in patients with shunt placement for hydrocephalus secondary to aqueductal stenosis. In these patients, thinned cerebrospinal fluid barriers secondary to long-standing increased intracranial pressure may predispose them to pneumocephalus. Temporary extraventricular drainage is an effective method of treatment in this group of patients. Two other etiologies are identified with significance to treatment, and the role of craniotomy is discussed.

Brain edema: ultrasound examination.

Sonographic examination of the brain in 10 patients who had cortical mass lesions was performed. Results were compared with findings of CT. In each case, brain edema surrounded the lesion, and the adjacent white matter had a diffusely echo-genic appearance that corresponded to the area of brain edema seen on CT.