The newer microsurgical techniques in neurosurgery.

The application of microsurgical techniques to neurological surgery has changed the treatment of several important neurological and neurosurgical diseases. Microsurgical decompression of the 5th and 7th nerves for trigeminal neuralgia and hemifacial spasm has become established as an accepted and effective technique. Application of the newer microvascular techniques in neurological surgery has increased the number of patients for whom surgical correction is possible and has, additionally, revolutionized the treatment of giant intracerebral aneurysms.

Acute dimethyl sulfoxide therapy in experimental brain edema: Part I. Effects on intracranial pressure, blood pressure, central venous pressure, and brain water and electrolyte content.

Albino rabbits with experimental brain edema produced by a cryogenic lesion or by a cryogenic lesion combined with a metabolic blocker, 6-aminonicotinamide, were given 1 g of a 10% solution of dimethyl sulfoxide (DMSO) per kg by intravenous bolus. Simultaneous recording of intracranial pressure (ICP), systemic arterial pressure (SAP), and central venous pressure and electroencephalography were performed while the animals were mechanically ventilated at a constant PaCO2 (PaCO2, 38 to 42 torr). One hour after the administration of DMSO, the rabbits were killed by air embolus, and the brain was removed promptly for the determination of wet and dry weights and electrolyte content. The ICP at 15, 30, and 60 minutes after DMSO was lower in both groups; ICP was significantly lower at 30 minutes (p less than 0.5) in the cold lesion group and at 15 minutes in the combined group (p less than 0.05). These was no significant change in SAP after DMSO in either group. There was s significant reduction of brain water content after DMSO in the combined lesion group (p less than 0.005 for the left hemisphere and p less than 0.025 for the right); there was no significant reduction of water content in the group with a cold lesion only.

Dimethyl sulfoxide for the treatment of intracranial hypertension: a preliminary trial.

Dimethyl sulfoxide (DMSO) has shown promise as a drug for the treatment of intracranial hypertension. In this report, we describe our experience in six patients, two who received a bolus administration of 10% DMSO and four who received a 20% solution titrated against the intracranial pressure (ICP). Five of the patients in this series suffered from severe head injury, and one had a cortical venous thrombosis associated with pregnancy. The first two patients were treated with a rapid infusion of a 10% solution of DMSO. Initially, the ICP was satisfactorily controlled using this method. Over time, however, fluid overload, severe electrolyte disturbances, and an ultimate loss of ICP control occurred. In subsequent patients, a 20% solution titrated against the ICP was used. Although ICP control was better achieved using this method of administration, problems with fluid management and electrolytes occurred again despite a high level of vigilance. In addition, because of the solvent properties of DMSO and its propensity over time to dissolve most standard intravenous infusion systems, mechanical difficulties in its administration were encountered in all six patients. The mechanism of action of DMSO is not well understood. It differs from the barbiturates, but acts too rapidly to function solely as a diuretic. The drug is extremely complex to use, and difficulties with its administration may make its risks ultimately greater than its potential benefits. Until more laboratory data are available concerning its use and better delivery systems are developed, neurosurgeons are cautioned against treating intracranial hypertension with DMSO.

Acute dimethyl sulfoxide therapy in experimental brain edema: part 2. Effect of dose and concentration on intracranial pressure, blood pressure, and central venous pressure.

Albino rabbits with experimental brain edema produced by a combined cryogenic and metabolic 6-aminonicotinamide lesion were administered intravenous dimethyl sulfoxide in varying concentrations and doses in the following manner: Subgroup A (concentration response) received a 1.0-g/kg bolus as a 10%, 20%, 30%, or 40% solution. Subgroup B (dose response) received as a 20% solution a 1.0-g/kg bolus, 1.5-g/kg bolus, or 2.0-g/kg infusion. Simultaneous recording of intracranial pressure (ICP), systolic arterial pressure (SAP), and central venous pressure and electroencephalography were performed while the animals were being mechanically ventilated at a constant PaCO2 (38 to 42 torr). There was significant lowering of ICP when compared to pretreatment values in Subgroup A in the 10% subset at 30 minutes (p less than 0.05) and in the 20% subset at 5 (p less than 0.05) and 30 (p less than 0.05) minutes. ICP was not significantly decreased in the 30% and 40% subsets. All animals of Subgroup B displayed significant reductions of ICP when compared to their pretreatment values. There was no significant change in SAP in either subgroup.

Acute dimethyl sulfoxide therapy in brain edema. Part 3: effect of a 3-hour infusion.

Albino rabbits with experimental brain edema produced by a combined cryogenic left hemisphere lesion and metabolic 6-aminonicotinamide lesion were administered a 3-hour intravenous infusion of dimethyl sulfoxide (DMSO). Simultaneous recording of intracranial pressure (ICP), systolic arterial pressure (SAP), and central venous pressure (CVP) and electroencephalography were performed while the animals were being ventilated mechanically to produce a constant Pa CO2 value (38-42 torr). At the end of the infusion, the brain water and electrolyte contents were measured. There was a persistent and progressive reduction of ICP during the infusion, the nadir occurring at 3 hours (p less than 0.005 from zero time), with no change in SAP or CVP. There was a reduction of brain water in both hemispheres when compared to untreated controls, but this was significant for the right hemisphere only (p less than 0.005). There was a significant reduction of the brain sodium content for both hemispheres, but no significant change occurred in brain potassium content. The DMSO infusion was effective not only in reducing ICP, but also in sustaining this reduction for 3 hours.

Carotid to distal vertebral artery bypass for vertebrobasilar ischemia. Case report.

A simple technique is described for a venous graft between the common carotid artery and the extracranial vertebral artery. In the case described, the vertebral artery was shown angiographically to be occluded and reconstituted by collateral vessels. This patient had symptoms of vertebrobasilar insufficiency which resolved postoperatively.

Having faith: experiencing coronary artery bypass grafting.

Even though coronary artery bypass grafting (CABG) is a commonly performed procedure, it is perceived by the client as a life-threatening event. When one is faced with a crisis, spiritual issues become extremely important. The purposes of this qualitative study were to discover what the spiritual needs are for CABG clients and how these needs are met during hospitalization. Grounded theory methodology was used to accomplish these goals. Data were collected through semistructured interviews with 17 adults, ages 34 to 83, who were 4 to 7 days post-CABG. Initially, the interview questions centered around how they felt when told of the need for surgery and how spiritual issues entered into that decision. From these questions a pattern emerged that led to the development of specific research questions. The major findings were that spiritual needs centered around having faith in their decision making, in the hospital staff (especially the nurses), and an overwhelming faith in God. CABG is a time of great stress, a time of feeling "pulled apart" and fragmented. Clients need to feel a sense of wholeness, not only physically and psychologically, but also spiritually. Because nurses are with clients on a consistent basis, they are able to assess and identify spiritual needs and provide needed spiritual resources. If nurses are educated to meet these needs it may help clients become more aware that nurses care about them as human beings who have a variety of needs with which the nurse is willing to assist.

Invasive procedures for treating herniated discs: clinical and cost considerations.

Low back injury is the most frequent cause of occupational time loss and disability. A small percentage of back injuries represent surgical disease, and great care must be taken in applying surgical therapy to this complex problem. Perhaps the most important factor in surgical management of low back injury is accurate clinical and neurodiagnostic assessment. Because of the high cost of poor surgical outcomes, diagnostic tests and surgical procedures should be chosen on the basis of efficacy rather than cost per individual case. This is because the cost of an unsatisfactory result quickly eliminates any savings accumulated by performing a less precise or less effective procedure. The best surgical outcomes appear to result from a process consisting of (1) thorough clinical evaluation, (2) electrophysiological studies in selected cases, (3) CT scanning with multiplanar reformatting and three-dimensional images as needed, and (4) individually designed surgical procedures. When used as described elsewhere, this sequence appears to best define the association between clinical and radiographic abnormalities, provide the best percentage of successful results, and potentially offer the greatest long-term economies.

Postoperative ulnar neuropathy.

Although compressive ulnar neuropathy developing during surgical procedures under general anesthesia has been recognized, clinical and electrophysiological features of this neuropathy have been incompletely described. During the past two years, we have seen eight patients with this complication, mainly following intra-abdominal or intrathoracic operations. Neuropathy was associated with a persistent severe deficit during a mean follow-up of 23.5 months (range, six to 96 months) after operation. Electrophysiological studies verified substantial Wallerian degeneration in the majority of patients. Clinical and electrophysiological data, as well as intraoperative findings in some patients, suggest that compression occurred at the cubital tunnel. These patients with ulnar neuropathy had a particularly poor prognosis, whether treated surgically (decompression or transposition) or medically. Prevention of ulnar nerve compression during major operations therefore assumes paramount importance.

Effect of cyclosporin A on murine natural killer cells.

In mice, cyclosporin A decreased the natural killer cell-enhancing effect of two interferon inducers, infective murine cytomegalovirus and nonreplicating Newcastle disease virus. It also inhibited murine cytomegalovirus replication at doses greater than 20 mg/kg, but it did not significantly inhibit interferon induction by Newcastle disease virus. In cell culture, cyclosporin A had no direct effect on the natural killer activity of spleen mononuclear cells derived from normal or murine cytomegalovirus-infected animals. However, at 50 micrograms/ml it significantly reduced the ability of interferon to enhance the natural killer activity of normal spleen cell suspensions. The inhibitory effect of cyclosporin A on natural killer cell activity in infected mice may be partly explained by its ability to block the action of interferon.

Acute dimethyl sulphoxide therapy in experimental brain oedema, effect of dose and concentration on brain water and electrolyte content.

Albino rabbits with experimental brain oedema produced by a combined left hemisphere cryogenic injury and a metabolic insult by a 6-aminonicotinamide (6-ANA) were administered intravenous dimethyl sulphoxide (DMSO) in varying concentrations and doses in the following manner: Subgroup A (concentration response) received 1.0 g/kg bolus of a 10, 20, 30, or 40% solution. Subgroup B (dose response) received as a 20% solution a 1.0 g/kg bolus, 1.5 g/kg bolus, or 2.0 g/kg infusion. One hour following administration of the agent, the animals were killed, their brains rapidly removed by craniectomy and brain water, sodium and potassium measured. Significant decreases in brain sodium and water content in the right hemisphere were noted in both subgroups A (p less than 0.05) and B (p less than 0.005) and in the left hemisphere in subgroup B only (p less than 0.005). There is an apparent effect on brain oedema by a DMSO mediated sodium dependent water mobilization.

Comparison of the effects of DMSO and pentobarbitone on experimental brain oedema.

The purpose of this report is to compare the effect of acute therapy with dimethyl sulphoxide (DMSO) and pentobarbitone on experimental brain oedema produced by a cryogenic lesion over the left hemisphere in albino rabbits. A group of animals received DMSO (1 mg/kg-10% solution) by intravenous bolus, and another group received a pentobarbitone intravenous 30-minute infusion (40 mg/kg). Intracranial pressure (ICP), systolic arterial pressure (SAP), central venous pressure (CVP), and EEG were studied. Brain water and electrolyte content were analyzed at one hour following the initiation of therapy. ICP was promptly reduced with both forms of therapy. A 66% reduction from control values was reached at 50 +/- 12 minutes with pentobarbitone, and a 45% reduction from control values was reached at 30 minutes with DMSO. There was no significant reduction in the water content of the brain with either form of therapy. A significant elevation in brain potassium content was noted following DMSO when compared to untreated controls. CVP was essentially unchanged in both groups. Pentobarbitone produced a reduction of SAP with a mean value of 20.3 torr at 45 minutes from infusion. DMSO produced no reduction of SAP. It is concluded that DMSO and pentobarbitone are just as effective in reducing ICP. DMSO has the capacity to maintain SAP which pentobarbitone does not have, thus assuring a better cerebral perfusion pressure.