Lennart Brandt

Causes of Unfavorable Outcome after Early Aneurysm Operation

In a consecutive series of 160 patients in Hunt and Hess Neurological Grades I to III who were operated upon for a ruptured supratentorial aneurysm within 3 days after the hemorrhage, 42 patients (26%) had an unfavorable outcome. Delayed ischemic cerebral dysfunction with permanent deficit accounted for the unfavorable outcome in 18 patients (43% of all unfavorable results or 11% of the total series), whereas the unfavorable outcome was due to deficit ascribed to surgical trauma in 11 patients (26% of all unfavorable results or 7% of the total series) and to the initial hemorrhage in 7 patients (17% of all unfavorable results or 4% of the total series). Impaired outflow of cerebrospinal fluid with shunt dependency occurred in 3% of the total series. Of the patients with an unfavorable outcome, 17 (40%) had had arterial hypertension before the hemorrhage. The incidence of unfavorable outcome in good grade patients (Grades I and II) was not influenced by timing of operation (Day 1, 2, or 3 after hemorrhage). The results favor the opinion that it is principally the patients condition during the acute stage that determines the outcome. (Neurosurgery 13:629-633, 1983).

Intracerebral Microdialysis of Glutamate and Aspartate Two Vascular Territories after Aneurysmal Subarachnoid Hemorrhage

Cerebral ischemia associated with subarachnoid hemorrhage may have severe consequences for neuronal functioning. The excitatory amino acid neurotransmitters glutamate and aspartate have been shown to be of particular importance for ischemia and ischemic neuronal damage. For seven patients who underwent early surgery for ruptured intracranial aneurysms, intracerebral microdialysis of glutamate and aspartate was performed to monitor local metabolic changes in the medial temporal (all seven patients) and subfrontal cortex (Patients 4 through 7). Samples were collected every 30 or 60 minutes, using an autosampler. The results show that extracellular glutamate and aspartate concentrations can rise to very high levels after surgery for subarachnoid hemorrhage and aneurysm. These increased levels of excitatory amino acids correlated well with the clinical course and neurological symptoms of the patients. Simultaneous sampling from two vascular territories (middle cerebral artery and anterior cerebral artery) also showed that a rise in extracellular glutamate and aspartate in one territory is not necessarily parallel with a rise in the other. The application of the microdialysis technique with an on-line assay system might be of value in the future for continuous monitoring of ischemic events to optimize treatment with, for example, blockers of glutamatergic neurotransmission.

Cognition and Adjustment after Late and Early Operation for Ruptured Aneurysm

Does early aneurysm operation, while lowering the overall management mortality, result in an unacceptable morbidity in terms of increased cognitive disturbances and psychosocial maladjustment? The present study evaluates quality of life, degree of cognitive dysfunction, and adjustment of 93 patients with satisfactory neurological recoveries after operations for ruptured supratentorial aneurysms. All patients had been in neurological Grades I to III (Hunt and Hess) after subarachnoid hemorrhage (SAH). Fifty-five patients were operated upon during the acute state, i.e., within 72 hours after bleeding (early surgery = ES), and 38 patients had been subjected to late surgery (LS), i.e., were operated on 9 days or more after SAH. Each patient was subjected to a clinical interview and a comprehensive neuropsychological investigation. The time interval between SAH and assessment varied between 12 and 103 months (mean, 56 months). The results confirm that there are indication of cognitive malfunctioning and psychosocial disturbances of varying severity and distribution in patients who have undergone LS. The pattern and distribution of sequelae after LS did not differ substantially from that in patients subjected to ES. The results offer strong support to the concept that remaining disturbances in cognition are mainly related to the impact of the initial hemorrhage per se. In patients with anterior communicating artery aneurysms, a larger decrease in tempo and perceptual vigilance was noted, suggesting that the subfrontal midline structures are particularly involved in processes demanding flexibility, attention, and capacity to adapt to novel demands in a perceptual situation.

Effects of Extracellular Calcium and of Calcium Antagonists on the Contractile Responses of Isolated Human Pial and Mesenteric Arteries

In isolated human pial arteries (diameter 0.4–0.5 mm), contractions were produced by potassium, noradrenaline, serotonin, and prostaglandin F2α. For comparison, experiments were also performed on human mesenteric arteries. Threshold concentration for potassium-induced contraction in pial arteries was about 10 mm; in mesenteric arteries it was 3–5 mm higher. In pial arteries the calcium antagonists nifedipine and nimodipine caused an almost complete relaxation of contractions induced by potassium at drug concentrations relaxing prostaglandin F2α-contracted vessels to only about 60%. Both nifedipine and nimodipine effectively inhibited contraction elicited by noradrenaline and serotonin in pial arteries. Nifedipine had a higher potency for relaxing cerebral than mesenteric arteries contracted by potassium (p < 0.001). No such difference was demonstrated for nimodipine. In pial arteries pretreated in a calcium-free medium for 30 min, potassium depolarisation elicited contractions reaching a maximum amplitude of about 40% of that evoked in normal Krebs solution. Both nifedipine and nimodipine effectively inhibited contractions induced by calcium in pial arteries pretreated in a calcium-free medium and depolarised by potassium. The results suggest that potassium, amines, and prostaglandin F2α activate isolated pial and mesenteric arteries by different calcium-dependent mechanisms and confirm the potent relaxant effects of nifedipine and nimodipine in these vessels.

EFFECTS OF TOPICAL APPLICATION OF A CALCIUM ANTAGONIST (NIFEDIPINE) ON FELINE CORTICAL PIAL MICROVASCULATURE UNDER NORMAL CONDITIONS AND IN FOCAL ISCHEMIA

Cat cortical arterioles and venules were exposed in vivo to the Ca2+ antagonist nifedipine under normal conditions and in focal ischemia. Topical application of nifedipine caused a marked, concentration-dependent arteriolar dilatation. The dilatatory responses increased significantly with decreasing arteriolar size. Perivenular microapplication of nifedipine invariably caused dilatation that was less pronounced but more long-lasting than that on the arteriolar side. Arterioles, which constricted after middle cerebral artery occlusion, invariably dilated following nifedipine application. These dilatatory responses were transient but could be repeated, and on some occasions were accompanied by a return of flow in vessels in which stasis had been present. The results suggest that nifedipine is able to dilate cerebral vessels both under normal conditions and when contracted during focal ischemia.

Effects of Iso- and Hypervolemic Hemodilution on Regional Cerebral Blood Flow and Oxygen Delivery for Patients with Vasospasm after Aneurysmal Subarachnoid Hemorrhage

Summary.Summary. Background: Arterial vasospasm after subarachnoid hemorrhage may cause cerebral ischemia. Treatment with hemodilution, reducing blood viscosity, and hypervolemia, increasing cardiac performance and distending the vasospastic artery, are clinically established methods to improve blood flow through the vasospastic arterial bed. Method: Eight patients with transcranial Doppler verified vasospasm after subarachnoid hemorrhage were investigated with global (two-dimensional 133Xenon) and regional (three-dimensional 99 mTc-HMPAO) cerebral blood flow (CBF) measurements, before and after 1/iso- and 2/hypervolemic hemodilution. Hematocrit was reduced to 0.28 from 0.36. Hypervolemia was achieved by increasing blood volume by 1100 ml. Findings: Isovolemic hemodilution increased global cerebral blood flow from 52.25±10.12 to 58.56±11.73 ml * 100 g−1 * min−1 (p<0.05), but after hypervolemic hemodilution CBF returned to 51.38±11.34 ml * 100 g−1 * min−1. Global cerebral delivery rate of oxygen (CDRO2) decreased from 7.94±1.92 to 6.98±1.66 ml * 100 g−1 * min−1 (p<0.001) during isovolemic hemodilution and remained reduced, 6.77±1.60 ml * 100 g−1 * min−1 (p<0.001), after the hypervolemic hemodilution. As a test of the hemodilution effect on regional CDRO2 an ischemic threshold was defined as the maximal amount of oxygen transported by a CBF of 10 ml * 100 g−1 * min−1 at a Hb 140 g/l which corresponds to a CDRO2 of 1.83 ml * 100 g−1 * min−1. The brain volume with a CDRO2 exceeding the ichemic threshold was 1300±236 ml before intervention. After isovolemic hemodilution the non-ischemic brain volume was reduced to 1206±341 (p<0,003). After hypervolemic hemodilution the non-ischemic brain volume remained reduced at 1228±347 ml (p<0.05). Interpretation: The present study of controlled isovolemic hemodilution demonstrated increased global CBF, but there was a pronounced reduction in oxygen delivery capacity. Both CBF and CDRO2 remained decreased during further hypervolemic hemodilution. We conclude that hemodilution to hematocrit 0.28 is not beneficial for patients with cerebral vasospasm after SAH.

Transforaminal steroid injections for the treatment of cervical radiculopathy: a prospective and randomised study

Steroid injections are often employed as an alternative treatment for radicular pain in patients with degenerative spinal disorders. Prospective randomised studies of the lumbar spine reveal contradictory results and non-randomised and most often retrospective studies of the cervical spine indicate pain reduction from steroid injections. No prospective randomised study on transforaminal steroid injections for the treatment of radicular pain in the cervical spine focusing on short-term results has been performed. Forty consecutive patients were employed for the study. The inclusion criteria were one-sided cervical radiculopathy with radicular distribution of arm pain distal to the elbow and corresponding significant degenerative pathology of the cervical spine at one or two levels on the same side as the radicular pain and visualised by MRI. A transforaminal technique was used for all injections. A positive response to a diagnostic selective nerve root block at one or two nerve roots was mandatory for all patients. The patients were randomised for treatment with steroids/local anaesthetics or saline/local anaesthetic. Only the neuroradiologist performing the blocks was aware of the content of the injection; all other persons involved in the study were blinded. Follow up was made 3 weeks after the randomised treatment by a clinical investigation and with a questionnaire focusing on the subjective effects from the injections. At follow up, there were no differences in treatment results in the two patient groups. Statistical analysis of the results confirmed the lack of difference in treatment effect. Further studies have to be performed before excluding steroids in such treatment and for evaluating the influence of local anaesthetics on radiculopathy in transforaminal injections.

Delayed Ischemic Deterioration in Patients with Early Aneurysm Operation and Intravenous Nimodipine

A consecutive series of 100 individuals with aneurysmal subarachnoid hemorrhage were subjected to early aneurysm operation followed by subsequent intravenous administration of the calcium antagonist nimodipine during the critical period for symptomatic vasospasm. A total of 85 patients were in Hunt and Hess neurological Grades I through III, and 15 were in Grade IV or V before operation. In 39 individuals the aneurysm was located in the anterior cerebral artery complex (ACA), in 29 it originated from the internal carotid artery complex (ICA), and in 32 individuals the ruptured aneurysm arose from the middle cerebral artery (MCA). Of the patients, 71% made a good neurological recovery; the morbidity was 22%, and the mortality was 7%. Of the Grade I-III patients, 79% made a good neurological recovery, and the mortality was 6%. Delayed ischemic cerebral deterioration with permanent dysfunction occurred in five patients, all with ruptured ACA aneurysms. No single patient in the ICA or MCA populations developed delayed ischemic deterioration with fixed neurological deficit despite the presence of several potential risk factors, especially among the MCA aneurysm patients.

Temporary clipping during early operation for ruptured aneurysm: preliminary report.

Temporary arterial occlusion was performed in 16 patients undergoing early aneurysm operation. Ten patients had a ruptured middle cerebral artery (MCA) aneurysm, and 6 had a ruptured anterior communicating artery aneurysm. Premature aneurysm rupture during operation necessitated temporary arterial occlusion in 10 patients. In 5 patients, temporary arterial occlusion was performed to facilitate dissection of the aneurysm. In 1 patient with a large MCA aneurysm, temporary occlusion was performed to provoke collapse of the completely exposed aneurysm sac, thus making clipping of the base possible. The results do not indicate that temporary occlusion by the standard aneurysm clips now in general use leads to angiographically detectable arterial wall changes or increased thromboembolic complications. Temporary clipping of the MCA proximal to the perforating arteries may be well tolerated for up to 20 minutes during early aneurysm operation. Temporary occlusion of one or both anterior cerebral arteries or temporary pericallosal clipping need not unconditionally lead to disastrous consequences if rendered necessary during aneurysm operations performed in the acute stage.

Ruptured middle cerebral artery aneurysm with intracerebral hemorrhage in younger patients appearing moribund: emergency operation?

Four women, aged 39 to 46 years, were urgently admitted to our neurosurgical unit after strokes. On admission, all appeared moribund, presenting with deep coma, pupils bilaterally dilated and fixed, decerebrate posture, and markedly abnormal respiratory patterns. Computed tomography revealed subarachnoid hemorrhage with an associated large intracerebral hematoma and pronounced shift of midline structures in all four cases. Because of the clinical appearance, the patients were given urea and were operated without preceding angiography. The origin of the hemorrhage was identified as a middle cerebral artery (MCA) bifurcation berry aneurysm in one patient and giant MCA aneurysms in the other three. The hematomas were evacuated, and the aneurysms were occluded. All four patients received intravenous nimodipine, none showed any sign of delayed ischemic deterioration, and all regained full consciousness within a few days. One patient died 3 weeks later from a pulmonary embolus. Three patients are presently at home with moderate focal neurological deficits and moderate to marked cognitive impairment. The psychosocial readjustment was very good in a patient with a left giant aneurysm, satisfactory in a patient with a right giant aneurysm, and unsatisfactory in a patient with a right berry aneurysm. The indications, ethical considerations, and technical aspects of operating on seemingly moribund patients who probably harbor a ruptured MCA aneurysm are discussed.