John P. Latchaw

Spinal Neurofibromas: A Report of 66 Cases and a Comparison with Meningiomas

A series of 66 spinal cord neurofibromas was analyzed for history, signs, surgical approach, and outcome. The tumors presented primarily with sensory symptoms. Plain films were abnormal in 1/2 of cases and 1/2 had a complete block. They were primarily intradural, and primarily thoracic. A conservative exam system was used for follow-up and 85% with pain had complete relief; 50% with motor loss had normal motor function, and 88% had normal sensation who had prior sensory loss. In comparison to meningiomas, the principal differences were that neurofibromas had an even sex distribution, a lower incidence of cord signs and symptoms, more frequent findings on plain x-rays, and higher cerebrospinal fluid protein. Surgical outcome was similar. Sacrifice of the involved root during removal usually did not produce a deficit. The series is compared with a similar series of meningiomas from the same institution over the same time period.

Treatment of acute focal cerebral ischemia with concentrated albumin

The object of the investigation was to study the effects of concentrated albumin upon the evolution of cerebral infarction. Twenty adult cats lightly anesthetized with ketamine hydrochloride underwent right middle cerebral artery (MCA) occlusion for 6 hours. Ten cats were not treated and 10 cats received concentrated (i.e., 25 g/100 ml) human serum albumin (5 ml/kg i.v.) at the time of MCA occlusion. The blood volume increased 30 to 40% in the cats receiving concentrated albumin. The hematocrit fell for 32 +/- 5% (SD) before occlusion to 23 +/- 6% at 2.5 hours after occlusion in treated cats, whereas the hematocrit in untreated cats remained stable at 35 +/- 5. Regional cerebral blood flow (rCBF) changes in the right sylvian region were similar in the untreated and treated groups. The mean rCBF before occlusion was 42 +/- 11 ml/100 g/minute in the untreated cats and 44 +/- 8 ml/100 g/minute in the treated cats. Untreated and treated cats had similar reductions of rCBF in the right sylvian region to less than or equal to 18 ml/100 g/minute at some point after occlusion. An index of erythrocyte flow and microcirculatory resistance was determined by measuring the transit of 99Tc-labeled erythrocytes in the right sylvian region. The erythrocyte transit time before occlusion was 10 +/- 2 seconds in the untreated group and 9 +/- 1 seconds in the treated group. After 6 hours, the erythrocyte transit was 19 +/- 3 seconds in the untreated group and 15 +/- 3 seconds in the treated group (p less than or equal to 0.1), suggesting that less microcirculatory impairment occurred in some treated cats. Electroencephalographic changes during the initial 3 hours of occlusion were less severe in the treated cats than in the untreated cats, suggesting that the collateral flow in the border zone of the MCA territory initially may have been improved by treatment. Impairment of carbon perfusion, ischemic edema, and neuronal alterations after 6 hours of occlusion were the same in both groups. Increased permeability of the blood-brain barrier to Evans blue dye, however, was more marked in the treated group. The findings of the study indicate that concentrated albumin does not substantially modify the evolution of cerebral infarction.

Treatment of acute focal cerebral ischemia with propranolol.

Propranolol has been found to have a protective effect in experimental myocardial ischemia. Protection of ischemic kidneys was subsequently demonstrated following treatment with propranolol and its weaker beta blocking isomer, d-propranolol. The objective of the present investigation was to study the effects of propranolol (i.e., racemic d,1 mixture) and d-propranolol upon regional cerebral blood flow (rCBF) and early ischemic changes following experimental middle cerebral artery (MCA) occlusion. Thirty adult cats, lightly anesthetized with ketamine hydrochloride, underwent 3 hours or right MCA occlusion. Ten cats were untreated. Ten cats were given a continuous infusion of propranolol (1 mg/kg/hr) for 4 hours beginning 1 hour before MCA occlusion and a 4 mg/kg bolus immediately before occlusion. Ten cats were given a continuous infusion of d-propranolol (0.5 mg/kg/hr) for 4 hours beginning 1 hour before MCA occlusion and a 2 mg/kg bolus immediately before occlusion. The therapeutic agents were injected directly into the right carotid artery. The rCBF in the right Sylvian region was not significantly different in the 3 groups. EEG changes also were similar. Carbon filling defects were found to be smallest in the d-propranolol-treated group. Light microscopic studies demonstrated a reduction in infarct size in the propranolol and d-propranolol groups. The findings of the investigation indicated that propranolol and d-propranolol do not have a deleterious effect on rCBF after MCA occlusion and suggested that these agents have a protective effect upon ischemic cerebral tissue.

Encouraging surgical results in walking patients with epidural metastases

The management of epidural metastases is in a state of controversy between combined surgical and radiation treatment and treatment by radiation alone. Review of the literature shows that one group, patients who are ambulatory before treatment, have been studied rarely. We analyzed our last 15 years of experience at the Cleveland Clinic and found 39 patients who were ambulatory preoperatively; 84% of these walked during the short term follow-up and 93% of the 1-year survivors walked. These data suggest that surgery has an important role in the management of ambulatory patients.

Treatment of acute focal cerebral ischemia and recirculation with d-propranolol

The purpose of the investigation was to evaluate the effects of d-propranolol upon temporary cerebral ischemia followed by a period of reperfusion, that is, a situation analogous to major cerebral artery embolization. Twenty adult cats, lightly anesthesized with nitrous oxide, underwent 4 hours of right middle cerebral artery (MCA) occlusion and 2 hours of recirculation. Ten cats were untreated and 10 cats received d-propranolol, the weak beta-blocking isomer of racemic (d,l) propranolol. The d-propranolol was infused directly into the right carotid artery at doses of 2 mg/kg, given as a bolus immediately before MCA occlusion, and 0.33 mg/kg/hour, given continuously for 6 hours beginning immediately after MCA occlusion. Systemic arterial blood pressure was similar in both groups, but heart rate was transiently reduced in the treated group immediately after the bolus injection of d-propranolol and MCA occlusion. Regional cerebral blood flow (rCBF), measured by the xenon-133 clearance technique, was not significantly different in the ischemic, right hemisphere. Electroencephalographic (EEG) activity changes in the ischemic, right hemisphere were similar in both groups, but there was significant deterioration of EEG activity in the left, nonischemic hemisphere of untreated cats after MCA reopening. Swelling of the ischemic, right hemispheres was similar in both groups and more severe than in previous studies wherein there was no recirculation phase. Carbon perfusion and blood-brain barrier changes were also similar. The results of the study failed to show a protective effect despite theoretical beneficial actions of d-propranolol. Also, the study demonstrated that d-propranolol does not have a detrimental effect upon rCBF in acute focal cerebral ischemia.

Racemic (d,1) and d-ISOMER Propranolol in Focal Cerebral Ischemia

Propranolol has been found to have a protective effect in experimental myocardial and renal ischemia22,28,27,8,29,14,12. Propranolol has been found to reduce regional cerebral blood flow (rCBF) in non-ischemic cats6. Since many stroke-prone patients receive this medication, this finding may present serious implications in cerebral ischemia. The objective of the present investigation was to study the effects of racemic (d,1) propranolol and its weak beta-blocking isomer, d-propranolol, upon rCBF and morphological changes in experimental acute focal cerebral ischemia.