Radioneurosurgery using the LINAC scalpel: technique, indications, and literature review.

Two available commercial units for radiosurgery are the modified linear accelerator (LINAC scalpel) and the gamma knife. Advantages of the LINAC scalpel over the gamma knife are its greater accuracy, the availability of a wide range of collimator sizes that allow for a more homogeneous field of radiation for large lesions, state-of-the-art computer software programs, and lower expense. Radiosurgery does not require an incision, is painless, and can be performed on an outpatient basis. It is ideally suited for the treatment of inaccessible, deep intracranial lesions that are radioresistant to conventional forms of radiotherapy, such as arteriovenous malformations, meningiomas, vestibular schwannomas, selected primary brain tumors, and cerebral metastases. Radiosurgery is an attractive treatment alternative to conventional neurosurgery for several intracranial lesions.

Utilization of resources for the maintenance of excellence in neurological surgery. The 1988 American Association of Neurological Surgeons presidential address.

In order to maintain the highest standards of care, neurosurgeons commit significant monies and time to continuing education. Significant time is devoted to national and regional organizations that work to assure standards for neurosurgical training, certification, and patient care. The continued increase in the sum of these efforts, both in money and time, indicates that a more efficient approach will be necessary in the future if neurosurgery and neurosurgeons are not to be overwhelmed or standards compromised.

Localized hypertrophic mononeuropathy involving the tibial nerve.

Localized hypertrophic neuropathy (LHN) is a disorder of unknown cause that presents with progressive, predominantly motor weakness in the distribution of a single nerve, with the histological appearance of the "onion bulb" formation. Because of its rarity, the condition is often ignored in the differential diagnosis of mononeuropathy. We report a case of LHN involving the posterior tibial nerve and review the literature.

Correlation of cerebral perfusion pressure and Glasgow Coma Scale to outcome.

Cerebral Perfusion Pressures (CPP) and Glasgow Coma Scale (GCS) scores were monitored to guide the management of severely head-injured patients. These measures were correlated to outcome (Glasgow Outcome Scale-GOS) in 136 consecutive patients at least 1 year after injury. The GOS showed highly significant positive correlations to either CPP or GCS assessments (p less than 0.001). Two parameters that are correlated with subsequent death in most patients include 1) highest (h) GCS = 3 or 4 (Day 1: 31 of 32 patients died, and Day 2: 19 of 19 patients died), and 2) CPP less than or equal to 60 mm Hg more than 33% of the hourly measures during Day 2 (36% of all subsequent deaths; 11% overlap with the highest Glasgow Coma Scale). The Day 2 measures identifying two groups that have a greater than 75% incidence of "good outcome" or GOS = 4 or 5 include 1) hGCS greater than or equal to 6 (N = 45) and 2) the average (a) CPP greater than or equal to 90 mm Hg (N = 26). Of the 45 patients with a GOS = 4 or 5 who had both CPP and GCS recorded on the third day, 44 were identified by these "good outcome" parameters.

Chemonucleolysis with chymopapain: results in 150 patients.

Chemonucleolysis with chymopapain has been advocated for the treatment of lumbar disc disease. When polled by a mail questionnaire, 150 consecutive patients who had undergone chemonucleolysis reported an overall success rate of only 40% and a failure rate of 60%. However, 57% of the patients were active or had only mild restriction of daily activities. Of those patients employed prior to injection, only 63% had returned to work. Those with workmen's compensation benefits fared considerably worse than those covered by third-party insurance (17% vs. 51% success). These results cast doubt on the long-term benefits of chymopapain in the treatment of lumbar disc disease.

Effects of aerosolized methylprednisolone on experimental neurogenic pulmonary injury.

We examined the effects of graded doses of methylprednisolone sodium succinate (MPSS)--0.05 (low), 0.5 (medium), and 5 mg/kg/hour (high)--on the development of neurogenic pulmonary injury in rabbits. The aerosolized drug was administered intratracheally for 5 hours beginning 10 minutes after a 2-minute elevation of the cerebrospinal fluid pressure (Pcsf) to 250 mm Hg. Compared to untreated control animals, the percentage of increase in pulmonary capillary permeability, as determined by 51Cr-labeled ethylenediaminetetraacetic acid clearance, was significantly less in the low and high dose MPSS groups. However, high dose MPSS was also associated with a significant decrease in compliance and increase in tissue hemorrhage (quantified by visual inspection). These results indicate biphasic effect of MPSS on alveolar capillary integrity after elevated Pcsf. The low dose minimized the extent of lung hemorrhage, pulmonary capillary leakage, and loss of lung compliance. In contrast, the high dose accelerated tissue hemorrhage and compliance loss, even though pulmonary capillary permeability was maintained near base line rates.

Cervical spine fractures with major associated trauma.

A detailed review of 88 consecutive patients placed in skeletal tong traction for cervical fractures by the University of Louisville Neurosurgical Service during a 5-year period from July 1, 1979, through June 30, 1984, was carried out. Of this group, 60% of the patients had a major associated injury consisting of major facial and skull fractures, cerebral contusions or intracerebral blood clots, cardiac or pulmonary contusions, major thoracic injuries including rib fractures and hemo- or pneumothoraces, intra-abdominal injuries, and major extremity fractures. An additional 24% of the patients had minor associated injuries, including facial or scalp lacerations, general body lacerations, or abrasions and cerebral concussions. Only 16% of patients with cervical fractures had no evidence of any other associated injury. Acute cervical spine fractures require prompt assessment and resuscitation by personnel from multiple specialties, usually available only in major trauma centers where experienced personnel capable of handling diverse injuries are always present.

The prediction of chronic pain outcome by psychological variables.

Followup telephone interviews were conducted with fifty-four former patients of a multidisciplinary clinic for the evaluation of chronic pain. Interviews were conducted between thirteen and fifty-five months following initial evaluation at the pain clinic. Followup levels of pain and physical disability were compared with the following measures obtained at initial evaluation: levels of pain and physical disability and scores on the Minnesota Multiphasic Personality Inventory (MMPI), McGill Pain Questionnaire (MPQ), and Zung Depression Inventory (ZDI). In general, both physical disability measures and psychological test scores obtained at initial interview were related to followup measures. However, when the predictive value of initial pain and physical disability was accounted for, psychological test scores tended not to produce further significant increment in predictability. These findings are interpreted to mean that the predictive value of these psychological tests stems less from their reflection of a psychological state or attitude with respect to pain, and more from their tendency to reflect ongoing level of pain, disability, and other pain sequelae. The results support the hypothesis that scores on these psychological tests are, at least in part, a reflection of the actual pain and disability and may not be subject to the same clinical interpretations that scores obtained from a psychiatric sample would be.

Accurate intracranial pressure monitoring: technical note.

Intracranial pressure (ICP) monitoring may be misleading or inaccurate in patients who have sustained cerebral death or who have had cerebrospinal fluid drainage (e.g., due to skull fracture or craniotomy). ICP recording in these patients requires particular attention to the monitoring technique to avoid misleading values that may result in inappropriate therapy. We review methods for obtaining accurate ICP readings from fluid-interface systems using either a ventricular catheter or a subarachnoid screw. We suggest attention to the following: (a) elevation of the pressure in the external tubing and connections to ensure that there are no microleaks , (b) injection of a small volume of saline intracranially, and (c) awareness of what constitutes a true ICP reading.

Isodense subdural hematoma presenting with paraparesis: case report.

Computerized tomography (CT) has replaced cerebral angiography in many institutions as the diagnostic test of choice in cranial trauma. However, isodense subdural hematomas can be a source of false-negative results on CT scans, resulting in omissions in therapy. The authors report a patient with bilateral isodense subdural hematomas who presented with paraparesis but was otherwise alert and fully oriented. The CT findings caused an initial diagnostic dilemma before being resolved.