Lincoln F. Ramirez

Complications and demographic characteristics of patients undergoing lumbar discectomy in community hospitals

We determined the incidence of acute, major complications in a population of 28,395 patients who underwent lumbar laminectomy for discogenic radiculopathy in the United States in 1980. This population was drawn from a broad cross-section of community hospitals and represented 31% of all patients who underwent laminectomy that year for this condition. Our cohort excluded patients with a) operations exceeding two disc levels, b) fusion, c) previous lumbar laminectomy, or d) coexistent discitis, spondylosis, spinal stenosis, myelopathy, or arachnoiditis. The incidence of death was 5.9 per 10,000. The causes of death were septicemia, myocardial infarction, and pulmonary emobolus. The incidence of at least one major complication was 157 per 10,000. The incidences of specific complications were as follows: infection requiring intravenously administered antibiotics, 30.7; major neurological deficit, 29.8; pulmonary embolus, 10.7; and myocardial infarction, 5.6. We studied four additional categories of complication. Patients were counted only when a second operation was required to treat the complication. The categories and incidence per 10,000 were as follows: incisional hematoma, 8.7; cerebrospinal fluid fistula, 10.5; ventral perforation, 1.6; and retention of a foreign body, 0.7. Among the patients whose hospitalizations were otherwise normal, 6.7% received a blood transfusion; of the patients whose hospitalizations were complicated, 24% required transfusion. The demographic characteristics of transfusion. The demographic characteristics of patients with a normal hospitalization were tabulated separately from those whose hospitalizations were complicated. Neurosurgeons performed 60% of the operations, and orthopedic surgeons performed 40%. The speciality of the surgeon was not a factor in determining the risk involved in surgery. Spinal anesthesia was used in 7% of the cases, and no pattern of complications emerged that was uniquely related to that technique.

Long-term psychosocial outcomes of anterior temporal lobectomy.

Summary:  Purpose: To examine the long‐term psychosocial outcomes of a consecutive series of patients who underwent anterior temporal lobectomy (ATL) compared with medically managed patients. This study focused primarily on actual long‐term changes (mean, 5 years) in life performance. There are relatively few long‐term controlled studies of actual lifetime performance changes.

The effects of colchicine in mammalian brain from rodents to rhesus monkeys

The injection of colchicine into rats and monkeys produced two different types of brain damage. At selected doses, intradentate colchicine preferentially destroyed DGC in rats, whereas damage was less selective and more severe in monkeys. Experiments were performed with different tubulin-binding drugs to investigate the structure-function relationship of tubulin binding and DGC death. The tubulin-binding characteristics of these and other drugs reported in the literature did not correlate with their ability to damage DGC. The role of seizure-induced cell death was investigated by recording the EEG in monkeys and in rats treated with phenobarbital. The data suggest that seizures are an infrequent epiphenomenon of colchicines action. We proposed that colchicine is not a selective neurotoxin and that it causes brain damage by inducing a non-specific inflammatory response. This response is both dose- and species-dependent. We concluded by discussing the medical implications of the present and proposed uses of colchicine.

Using a national health care data base to determine surgical complications in community hospitals: lumbar discectomy as an example.

To determine the incidence of acute complications of an operation in a large cross-section of U.S. community hospitals, we developed a method that combines the screening of discharge abstracts with the sampling of medical records. Our target patients were those who underwent discectomy for routine lumbar discogenic radiculopathy. We assembled 39,389 discharge abstracts of patients who underwent lumbar discectomy in the U.S. in 1980. This population contained some nontarget patients with a) errors in principal diagnosis or procedure, b) operations exceeding two levels, c) fusion, d) previous laminectomy, or e) problems of the lumbar spine in excess of routine disc disease. Screening of discharge abstracts allowed us to exclude some of these patients. Those remaining were then divided by the reported hospitalization into three groups: 1) death, 2) nonfatal complication, and 3) normal hospitalization. A sample of patients from each group was selected for detailed study, and questionnaires were mailed to hospital medical records departments to confirm the hospitalization and to obtain other medical information unavailable in the abstract. With this information, we 1) removed the remaining nontarget patients (a through e above); 2) categorized reported complications as erroneous, preexistent, trivial or major; 3) calculated the incidence of major complications; and 4) assessed the reliability of the discharge abstract data. Principal diagnosis and procedure were reliably coded in 96.5% of abstracts. No deaths were reported in error and none were excluded in error. Among patients who had complications, 4% of the abstracts incorrectly indicated complications, and 11% omitted one complication while correctly reporting others.(ABSTRACT TRUNCATED AT 250 WORDS)

Pain Relief after Hypophysectomy

&NA; Thirteen series of patients who underwent surgical or chemical hypophysectomy for the relief of pain associated with cancer were reviewed. In 10 series, involving 334 patients with breast or prostate cancer, surgical hypophysectomy produced pain relief in 70% of the patients afflicted with either tumor, including some with no evidence of hormone dependence. These results were then compared with the results of chemical hypophysectomy. This procedure was performed in 3 series involving 533 patients, of whom 24% had cancer other than breast or prostate. Chemical hypophysectomy produced pain relief in over 75% of the patients, regardless of tumor type or hormonal dependence. The possible role of the pituitary, the hypothalamus, and endogenous opiates in mediating the pain relief associated with hypophysectomy was examined. The mechanism by which pain relief is achieved remains unclear, but there is significant evidence that this relief is not related directly to the expected fall in the levels of known pituitary hormones. Evidence is provided that pain relief is the result of a hypothalamic pain‐suppressing capability triggered by hypophy‐sectomy. On the basis of both clinical data and the mechanism of action, we conclude that surgical and chemical hypophysectomy are fundamentally similar procedures. (Neurosurgery 14:499‐504, 1984)

Creating physical 3D stereolithograph models of brain and skull.

The human brain and skull are three dimensional (3D) anatomical structures with complex surfaces. However, medical images are often two dimensional (2D) and provide incomplete visualization of structural morphology. To overcome this loss in dimension, we developed and validated a freely available, semi-automated pathway to build 3D virtual reality (VR) and hand-held, stereolithograph models. To evaluate whether surface visualization in 3D was more informative than in 2D, undergraduate students (n = 50) used the Gillespie scale to rate 3D VR and physical models of both a living patient-volunteers brain and the skull of Phineas Gage, a historically famous railroad worker whose misfortune with a projectile tamping iron provided the first evidence of a structure-function relationship in brain. Using our processing pathway, we successfully fabricated human brain and skull replicas and validated that the stereolithograph model preserved the scale of the VR model. Based on the Gillespie ratings, students indicated that the biological utility and quality of visual information at the surface of VR and stereolithograph models were greater than the 2D images from which they were derived. The method we developed is useful to create VR and stereolithograph 3D models from medical images and can be used to model hard or soft tissue in living or preserved specimens. Compared to 2D images, VR and stereolithograph models provide an extra dimension that enhances both the quality of visual information and utility of surface visualization in neuroscience and medicine.

Epilepsy surgery outcome among US veterans.

We retrospectively studied the outcome of anterior temporal lobectomy (ATL) among a population of veterans and evaluated outcome related to comorbidities. Veterans who underwent ATL between 1990 and 2001 at the Veterans Administration Hospital in Madison, Wisconsin, were included. Data related to postoperative seizure outcome, quality of life outcome, and employment outcome were collected. Factors associated with favorable outcome and outcome related to comorbidities were evaluated. Twenty-seven patients were entered into the study. The mean age at onset of seizures was 25 years (+/-10.2). History of a non-substance abuse psychiatric diagnosis, and substance abuse was present in 26% (7/27) and 30% (9/27), respectively, prior to surgery. While 66.6% (18/27) had a good outcome (Engels Class I), no difference in the frequency of good outcome was seen among the patients with a history of substance abuse, other psychiatric diagnosis (71%), or no psychiatric diagnosis (67%). There was a significant correlation between seizure outcome and quality of life score (r(s)=0.67, p<0.001) and postoperative employment gains (r(s)=0.48, p=0.01). Outcomes among veterans that underwent ATL can be satisfactory even in the context of the late mean age of epilepsy onset and the psychiatric diagnoses that were present in this sample.

Epilepsy surgery improves regional glucose metabolism on PET scan - A case report

SummaryA patient with medically intractable complex partial epilepsy was evaluated for epilepsy surgery by electroencephalograph recording with depth electrodes and 18F-fluorodeoxyglucose positron emission tomography (PET). A small calcified arteriovenous malformation was excised from the left parietal lobe, and the patient became seizure free. Baseline and language stimulation PET scans were obtained preoperatively and 10 months postoperatively. There was a significant increase in glucose metabolism of the left temporal lobe postoperatively, which we interpret as evidence of improved neuronal function. We suggest that this case represents evidence for a functional, and reversible, inhibition of neuronal metabolism by epileptic activity.