Diagnosis and management of brachial plexus lesions in cancer patients.

Brachial plexus dysfunction is a well-known complication of cancer. Metastatic brachial plexus (RBP) are the most common causes. The distinction between MBP and RBP is very important but is not easy to make. This article presents in detail the distinguishing features of these types of brachial dysfunction. In regard to treatment, radiation, chemotherapy, narcotic analgesics, paravertebral nerve blocks, dorsal rhizotomy, dorsal root entry zone procedure, and high contralateral cordotomy are helpful in managing the symptoms of MBP. Transdermal electrical nerve stimulation, dorsal column stimulators, neurolysis, and neurolysis with omentoplasty have been tried in RBP. Good physical therapy, tricyclics, antiarrhythmics, anti-convulsants, nonsteroidal anti-inflammatory drugs and steroids are helpful in both conditions.

Inhibition of human glioma cell proliferation and glutathione S-transferase by ascorbyl esters and interferon.

The in vitro effect of ascorbyl esters (ascorbyl-stearate [As-S] and -palmitate [As-P]) and interferon (recombinant human interferon-a2b [rHuIFN-a2b]) on human glioma (U-373) cell proliferation, viability and glutathione-S-transferase (GST) activity was studied. The effect of As-S, As-P and rHuIFN-a2b on cell proliferation and viability was evaluated by [3H] Thymidine incorporation and colorimetric MTT assays, respectively. Incubation of glioma cells with As-S, As-P or rHuIFN-a2b for 24 h resulted in a dose dependent inhibition of cell proliferation (IC50 = 68.0 microM As-S, 86.0 microM As-P and 47.3 Units/ml rHuIFN-a2b), and moderate decrease of cell viability. It was found that As-S was a more efficient inhibitor of cell proliferation, viability and GST activity than As-P. GST from U-373 cells was purified. The activity of purified GST towards 1-chloro-2,4-dinitrobenzene (CDNB) was inhibited in a dose dependent manner by ascorbyl esters (I-50 = 27.5 microM As-S and 56.0 microM As-P) but not by rHuIFN-a2b. GST activity of cytosol isolated from U-373 cells which were previously treated with As-S (150 microM) or rHuIFN-a2b (150 units/ml) for 0, 2, 5, 10, 20 and 30 min was sharply decreased during 5 to 10 min of treatment and increased at longer durations of treatment.

Inhibition of cell proliferation and glutathione S-transferase by ascorbyl esters and interferon in mouse glioma.

Mouse glioma-26 (G-26) cell line established in this laboratory was used in the study. The in vitro effect of ascorbyl esters, viz., ascorbyl-palmitate (As-P), -stearate (As-S) and mouse interferon-alpha/beta (MulFN-alpha/beta) on the glioma cell viability, proliferation and glutathione S-transferase (GST) activity was investigated. Cell viability and proliferation were examined by colorimetric MTT assay and [3H]-thymidine incorporation, respectively. Incubation (24h) of G-26 cells with As-S, As-P or MulFN-alpha/beta, resulted in a dose dependent decrease in cell viability (IC50 = 125 microM As-S; 175 microM As-P and 3.6 x 10(4) U/ml MulFN-alpha/beta) and proliferation (IC50 = 157 microM As-S; 185 microM As-P and 3.6 x 10(4) U/ml MulFN-alpha/beta). A combined exposure to 175 microM As-S and 800 U/ml of MulFN-alpha/beta resulted in a greater than an additive effect on cell viability and proliferation. The inhibition of cell proliferation/viability by interferon was species specific and was observed only with homologous MulFN-alpha/beta, but not with human interferon-alpha lymphoblastoid or human interferon-beta. Ascorbyl esters inhibited cytosolic GST activity (1-50 = 15.0 microM As-S and 28.5 microM As-P) towards 1-chloro-2,4-dinitrobenzene in a dose dependent manner. The apparent Ki values for affinity purified GST, deduced from Dixon plots were 0.95 microM and 2.0 microM for As-S and As-P, respectively. Significant inhibition of GST was also observed in the cytosol isolated from G-26 cells exposed to 300 microM As-S or 800 U/ml MulFN-alpha/beta.

CT-guided nerve root block and ablation.

We report our experience in performing 52 CT-guided peripheral nerve root blocks and 27 CT-guided nerve root ablations. The nerve root block procedures were performed as diagnostic tests to determine the clinical significance of equivocal herniated disk or foraminal stenosis (n = 33) and before nerve root ablations (n = 19). To evaluate the clinical significance of these nerve root blocks, we performed 52 procedures at the vertebral level where a herniated disk or foraminal stenosis had been identified on CT or MR images. In 51 of 52 cases, the procedures were successful in anesthetizing the intended nerve root, which allowed us to determine whether that particular nerve root was the source of pain. By relieving or not relieving pain, the results of the diagnostic nerve root blocks helped determine whether a protrusion or foraminal stenosis was clinically significant. The nerve root ablations were done exclusively for treatment of pain in patients with malignant disease. Significant relief of pain was obtained in 17 (63%) of 27 patients. The thoracic nerve ablations were the most successful (9/10 or 90%) because the correct thoracic nerve innervation to the offending lesion could be identified. The lumbosacral nerve ablation procedures were the least successful (6/14 or 43%) because the innervation of the pelvic neoplasms was complex, arising from multiple lumbosacral nerves that often were bilateral. Equivocal foraminal stenosis and disk protrusion are common findings on CT and MR imaging, and CT-guided nerve block procedures can help determine which of these findings are clinically significant. CT-guided nerve root ablations have limited efficacy but can help control pain in patients with a malignant disease, especially when the pain is in the distribution of a thoracic nerve dermatome.

Major cerebral infarction from tumor embolus.

A major right hemispheric infarct developed in a 31-year-old man within forty-eight hours of lung resection for metastatic synovial-cell sarcoma. Post mortem exam revealed tumorous occlusion of the right internal carotid artery. Major stroke from cerebral tumor embolus should be seriously considered in patients with primary or metastatic lung cancer who have had a very recent pneumonectomy, especially when there are symptoms and signs of multi-organ or extremity ischemia.

Improved technique for CT-guided celiac ganglia block.

Celiac nerve blocks have been performed without radiologic guidance, but recently several groups have reported computed tomography (CT)-guided techniques. The authors present a new technique of CT-guided celiac nerve block using an 18 gauge Teflon catheter, which permits a test block dose and permanent alcohol block with one procedure. The results of this new technique were very encouraging. Of nine cancer patients who had the test block, seven had good pain relief; these same patients had good pain control with the permanent block. Of six patients with pancreatitis, six had good pain relief from the test block, and three had some long-term relief from the permanent block.

Wernicke's encephalopathy: a predictable complication of hyperemesis gravidarum.

Wernicke's encephalopathy occurred during prolonged intravenous feeding in two patients with hyperemesis gravidarum. Delay in diagnosis caused a protracted illness and persisting neurologic deficits in both patients. Because of its association with chronic alcoholism, the possibility of Wernicke's encephalopathy may not be considered early enough, if at all, in other situations; it is too frequently not discovered until postmortem examination. The disease may complicate other neurologic disorders due to nutritional deficiency, but can be prevented by the timely administration of parenteral thiamine.

Intracarotid chemotherapy of glioblastoma after induced blood-brain barrier disruption.

Intracarotid chemotherapy has been suggested as an additional mode of therapy in patients with brain tumors. Seven comatose patients received intracarotid 5-fluorouracil and adriamycin after intracarotid infusion of 25% mannitol to open the blood-brain barrier at the tumor site. Five of seven patients became fully functional for 3-12 months. Another 11 patients entered the study, of which nine are currently receiving therapy and are functional, and two have died, one from brain herniation. The results are encouraging and support the need for further research of this therapeutic method.

Brachial plexus lesions in patients with cancer: 100 cases.

In patients with cancer, brachial plexus signs are usually caused by tumor infiltration or injury from radiation therapy (RT). We analyzed 100 cases of brachial plexopathy to determine which clinical criteria helped differentiate tumor from radiation injury. Seventy-eight patients had tumor (34 with previous RT), and 22 had radiation injury. Severe pain occurred in 80% of tumor patients but in only 19% of patients with radiation injury. The lower trunk (C7-8, T1) was involved in 72% of the tumors, and 32% also had epidural tumors. Seventy-eight percent of the radiation injuries affected the upper plexus (C5-6). Horner syndrome was more common in tumor, and lymphedema in radiation injury. The time from RT to onset of plexus symptoms, and the dose of RT, also differed. For symptoms within 1 year of RT, doses exceeding 6000 R were associated with radiation damage, whereas lower doses were associated with infiltration. Therefore, painless upper trunk lesions with lymphedema suggest radiation injury, and painful lower trunk lesions with Horner syndrome imply tumor infiltration.