✓ The author describes five instances of extradural hematoma that developed during craniotomy. The hematomas extended basally from an original craniotomy near the midline and four required immediate additional surgical exposure. This rare complication should be remembered during craniotomy if the brain appears to be swelling without obvious reason.
Report of five cases
Timo Kuurne and Henry Troupp
✓ Hydrostatic pressure with artificial cerebrospinal fluid (CSF) was applied through a needle inserted into the cisterna magna of rabbits breathing spontaneously. Blood pressure, confluens sinuum pressure and oxygen tension, respiratory rate and volume, and acid-base balance were recorded until respiratory arrest. Blood pressure and confluens sinuum pressure and respiratory volume rose; confluens sinuum oxygen and arterial carbon dioxide tension dropped. The significant similarities and differences in changes in the same parameters following local cold injury to the brain are discussed. Comparisons between different experimental models for raised intracranial pressure must take into consideration the differing reactions of the brain.
G. af Björkesten and Henry Troupp
With a Note on Experimental Arterial Aneurysms
Henry Troupp and Torbjörn Rinne
Markku Kaste and Henry Troupp
✓ Changes in the blood pressure, cerebral sinus pressure, cerebral venous oxygen tension, acid-base balance, respiratory frequency, and respiratory minute volume were studied in the rabbit after a lethal cold injury to the brain. About half of the animals responded to the injury with a quick rise in cerebral sinus pressure and in its relation to blood pressure (CSP/BP); in the other half, cerebral sinus pressure and the CSP/BP ratio rose more slowly. Changes in the CSP/BP ratio correlated well with criteria for changes in respiratory performance. The changes in cerebral venous oxygen tension were reasonably uniform: a dip during freezing, an overshoot to a mean of 1.6 times the original level (about 30 mm Hg) immediately after injury, a gradual return to the pretraumatic level, and then a drop to lower levels. The brain injury led to a respiratory alkalosis that became more pronounced the longer the animals lived. Considered with CSP/BP ratio, respiratory reaction to the brain injury may provide an early and accurate prognosis. The fact that at the time of death the cerebral perfusion pressure was still within a range believed safe for the brain shows that an actual brain injury, in addition to raised intracranial pressure, is important in such experiments and emphasizes the inappropriateness of comparing levels of intracranial pressure raised by a variety of methods.
A Comparison Between Patients with Verified Aneurysms and Patients with Normal Angiograms
G. af Björkesten and Henry Troupp
Henry Troupp and Gunnar af Björkesten
✓ A controlled trial involving 178 subarachnoid hemorrhage patients in good condition (Grade 1) and with single intracranial arterial aneurysms is reported. The decision to treat with stalk ligature or conservatively was made at a comparatively late stage, on an average of 51 days after the initial hemorrhage. After a follow-up time of ½ to over 5 years (average 3½ years), there was no statistical difference between the results in the operated and unoperated groups. The majority of the nine fatal recurrences among the 92 unoperated patients occurred within the first months after initial hemorrhage; only one death occurred later than 4 months after hemorrhage. There was one operative death in the hospital among the 86 operated patients; all the four late deaths from reasons related to the aneurysm occurred in patients who had had operations other than aneurysmal stalk ligatures performed. It is concluded that Grade 1 aneurysm patients have such a good natural prognosis that the value of late surgery seems limited, even if performed without mortality or increased morbidity, and in the form of stalk ligature.
Nils Lundberg, Henry Troupp and Henry Lorin
Henry Troupp, Markku Kaste, Timo Kuurne and Matti Huttunenm
Stephen L. Ondra, Henry Troupp, Eugene D. George and Karen Schwab
✓ The authors have updated a series of 166 prospectively followed unoperated symptomatic patients with arteriovenous malformations (AVM's) of the brain. Follow-up data were obtained for 160 (96%) of the original population, with a mean follow-up period of 23.7 years. The rate of major rebleeding was 4.0% per year, and the mortality rate was 1.0% per year. At follow-up review, 23% of the series were dead from AVM hemorrhage. The combined rate of major morbidity and mortality was 2.7% per year. These annual rates remained essentially constant over the entire period of the study. There was no difference in the incidence of rebleeding or death regardless of presentation with or without evidence of hemorrhage. The mean interval between initial presentation and subsequent hemorrhage was 7.7 years.