Postoperative Cerebral Vasospasm Research Articles

Proposal of a predictive score for the occurrence of postoperative cerebral vasospasm: analysis of a large single institution retrospective series and literature review.

Proposal of a predictive score for the occurrence of postoperative cerebral vasospasm: analysis of a large single institution retrospective series and literature review.

Management of postoperative cerebral vasospasm in skull base surgeries: A systematic review of case reports and series.

This study provides a comprehensive overview of the management of postoperative vasospasm after skull base surgeries. This phenomenon is rare but can be of serious sequelae. Medline, Embase, and PubMed Central were searched, along with examining the references of the included studies. Only case reports and series that reported vasospasm following a skull base pathology were incorporated. Cases with pathologies other than skull base, subarachnoid hemorrhage, aneurysm, and reversible cerebral vasoconstriction syndrome were excluded from the study. Quantitative data were presented as mean (Standard Deviation) or median (range), accordingly, while qualitative data were presented as frequency (percentage). Chi- square test and one-way analysis of variance were used to assess for any association between the different factors and patient outcomes. We had a total of 42 cases extracted from the literature. The mean age was 40.1 (±16.1) with approximately equal males and females (19 [45.2%] and 23 [54.8%], respectively). The time to develop vasospasm after the surgery was 7 days (±3.7). Most of the cases were diagnosed by either angiogram or magnetic resonance angiography. Seventeen of the 42 patients had pituitary adenoma as the pathology. Anterior circulation was nearly affected in all patients. For management, most patients received pharmacological with supportive management. Twenty-three patients had an incomplete recovery as a result of vasospasm. Vasospasm following skull base operations can affect males and females, and most patients in this review were middle-aged adults. The outcome of patients varies; however, most patients did not achieve a full recovery. There was no correlation between any factors and the outcome.

Deterioration of non-lesional side evoked potential during unilateral single unruptured intracranial aneurysm clipping: incidental finding or true warning signal?

To investigate patients presenting non-lesional side evoked potential (EP) deterioration without lesional side EP change during unruptured intracranial aneurysm (UIA) clipping surgery. This single-center, retrospective study included patients who underwent single UIA clipping with intraoperative neuromonitoring between March 2017 and December 2021. For targeting lateralized surgery group, we included the UIAs located in middle cerebral artery bifurcation, middle cerebral artery, anterior choroidal artery, and internal carotid artery. Motor evoked potentials (MEPs) and somatosensory evoked potentials (SSEPs) were measured during surgery. Postoperative neurologic deficits (PNDs) were defined using the modified Rankin Scale. A total of 315 patients were enrolled. Twenty-seven patients (8.6%) presented with deterioration of one or more EPs. Nine patients showed non-lesional side EP deterioration first without lesional side EP change. Five patients showed only non-lesional side EP deterioration and did not present PNDs or radiologic complications. Three patients showed non-lesional side EP deterioration followed by bilateral EP warnings, one of which had PND due to postoperative subarachnoid hemorrhage. The other two patients had no PND but showed postoperative cerebral vasospasm. This study provides a basis for decisions regarding the firstly appeared non-lesional side EP deterioration without lesional side EP change during unilateral UIA clipping. Further studies with larger sample sizes are needed to generalize these findings.

Platelets-to-serum Ca2+ ratio as a risk factor for postoperative cerebral vasospasm in surgically treated aneurysmal subarachnoid hemorrhage patients.

Aneurysmal subarachnoid hemorrhage (aSAH) generally requires surgical intervention to secure the aneurysm(s). Cerebral vasospasm (CVS) is a common complication of aSAH that occurs before and after a clipping or coiling procedure. However, we have limited options for the prevention or early detection of CVS by far. Although some biomarkers were studied regarding the purpose, some of which are rather complicated and actually hard to obtain. We conducted this study to investigate the potential correlations between the platelets-to-serum Ca2+ ratio (P/C) and the occurrence of postoperative CVS in aSAH patients. We enrolled 262 patients in this retrospective study, clinical features and lab results were collected from an electronic medical record (EMR) system. The variables were consecutively analyzed in univariate and multivariate analyses; p-values < 0.05 were considered significant. The predictive values of several certain variables for CVS were further assessed through receiver operating characteristic (ROC) analysis. The prevalence of CVS in our study was 33.6%. Patients suffering from CVS had significantly increased P/C levels compared to those who did not (p = 0.045). Multivariate logistic analysis revealed that P/C was independently associated with postoperative CVS (p = 0.041). ROC curves demonstrated prominent interactions between P/C and clinical rankings, in terms of predicting postoperative CVS in aSAH patients. At a cutoff value of 112.53, patients with higher P/C levels in the early stage of aSAH were more likely to develop symptomatic CVS after aneurysm occlusion (p = 0.004). Among aSAH patients, a higher P/C at admission increases the risk of postoperative CVS events and, with easy access, it may serve as a novel predictor for the complication.

A CASE OF MIDDLE CEREBRAL ARTERY INFARCT FOLLOWING UNEVENTFUL CLIPPING OF ANTERIOR COMMUNICATING ARTERY ANEURYSM

Background: Aneurysms of the anterior communicating artery are the most frequently encountered intracerebral aneurysms in routine neurosurgical practice. Management of intracerebral aneurysm involves aneurysm clipping or endovascular coil aneurysm embolisation. However, to the best of our knowledge, there is no reported case of an isolated ipsilateral middle cerebral artery infarction following clipping of anterior communicating artery aneurysm. Case Description: A 65-year-old female with hypertension presented with a history of giddiness, fall and altered sensorium. The patient had a Glasgow Coma Scale (GCS) score of 12, and further investigation of the magnetic resonance imaging on suspicion of stroke revealed subarachnoid haemorrhage in the bilateral parietal sulcus, left Sylvain ssure, left ambient and quadrigeminal cisterns with intra-ventricular extension. The patient was subsequently referred for neurosurgery consultation. Computed tomography (CT) angiogram conrmed the presence of a ruptured anterior communicating artery aneurysm. The neurological assessment showed reduced responsiveness to verbal commands, with a Hunt and Hess score of 3. The patient underwent uneventful clipping of the aneurysm. Postoperatively, the patient did not wake up from anaesthesia and had persistently elevated blood pressure and right-sided hemiplegia. On the third day of postoperative care, a CT head scan revealed a left middle cerebral artery infarction with a midline shift. Decompressive craniotomy was performed, and following this procedure, the patient improved in sensorium with residual right-sided hemiplegia Conclusion: This case report presents an undetected new micro embolism or postoperative cerebral vasospasm as possible causes for the development of cerebral infarct in patients with subarachnoid haemorrhage following an aneurysm rupture.

Clinical Efficacy of Shenmai Injection in the Treatment of Cerebral Vasospasm after Ruptured Aneurysm Surgery

Objective: To investigate the therapeutic effect of Shenmai Injection on postoperative cerebral vasospasm in patients with ruptured aneurysms. Methods: Seventy patients undergoing craniotomy for ruptured aneurysms in our hospital were selected as study subjects and randomly divided into control (n = 33) and research (n = 37) groups, they were treated with nimodipine and nimodipine combined with Shenmai injection after operation. The blood flow velocity in the middle cerebral artery (MCA) before and at 1, 3, 7, 11 and 14 days after surgery and the incidence of cerebral vasospasm during these days were compared, and the GCS scores at 14 days postoperatively and GOS scores at 6 months postoperatively were compared between the two groups. Results: There were no statistically significant differences in the occurrence of cerebral vasospasm, GCS or GOS scores between the two groups (P > 0.05), but the period of postoperative cerebral vasospasm in the study group was significantly shorter than that in the control group. Conclusion: Shenmai injection has the effect of shortening the cycle of occurrence of cerebral vasospasm after the operation of ruptured aneurysms, promoting patients to recover as early as possible and reducing their physical and mental burden.

Atorvastatin reduces cerebral vasospasm and infarction after aneurysmal subarachnoid hemorrhage in elderly Chinese adults.

We explored whether acute atorvastatin treatment would improve clinical outcomes and reduce the incidence of cerebral vasospasm after aneurysmal subarachnoid hemorrhage in elderly Chinese adults. Patients (60 to 90 years old) were admitted to intensive care units after surgery to clip or embolize their aneurysms. We assessed 592 patients and assigned 159 to receive atorvastatin (20 mg/day) and 158 to receive placebo once daily for up to 14 days. The primary outcome was the Glasgow outcome scale at 6 months, and secondary outcomes were cerebral vasospasm, 30-days all-cause mortality, cerebral infarction, and delayed ischemic neurological deficit. The incidence of postoperative cerebral vasospasm (39.3% vs 56%, P =0.004) and cerebral infarction (18.7% vs 27.3%, P=0.027) were significantly lower in the atorvastatin group. The study did not detect benefits in the use of atorvastatin for 6 months clinical outcome or 30-day all-cause mortality, but it suggests that atorvastatin together with nimodipine can reduce cerebral vasospasm and cerebral infarction after subarachnoid hemorrhage.

Effects of evidence-based nursing on the psychological status and complications after interventional embolization of intracranial aneurysms

Objective To investigate the effects of evidence-based nursing on the psychological status, operation associated complications and short-term prognosis of patients with intracranial aneurysms after interventional embolization. Methods A total of 150 patients undergoing elective interventional embolization in the hospital from May 2012 to May 2016 were randomly divided into the control group and the observation group with 75 patients each. The control group were given routine nursing care while the observation group were given evidence-based nursing. The incidence of operation associated complications and postoperative cerebral vasospasm were compared between the two groups. The changes in scores of the Self-Rating Anxiety Scale (SAS) , Self-Rating Depression Scale (SDS) , Somatization Symptom Checklist (SCL-90) and Glasgow Outcome Scale (GOS) before and after intervention were compared. Results No postoperative cerebral vasospasm was observed in the observation group, and the incidence of operative complications was 4%. In the control group, cerebral vasospasm occurred in 7 cases, and the incidence of operative complications was 17.3%. Before discharge, SAS score (42.26±3.77) and SDS score (40.67±6.44) in the observation group were lower than those in the control group (t=8.478, 4.507; P<0.001) . No death cases in these two groups. Three months later after operation, patients with GOS grade 5 in the observation group was 30.67%, and it was 13.33% in the control group. There was significant difference of GOS classification between the two groups (H=15.520, P<0.01) . Conclusions Evidence-based nursing can help reduce the incidence of cerebral vasospasm after interventional embolization in patients with intracranial aneurysms, improve their anxiety and depression, and optimize short-term prognosis. Key words: Intracranial aneurysm; Evidence-based nursing; Cerebral vasospasm; Interventional embolization

Glycerol fructose combined with vitamin B6 is beneficial to postoperative recovery of patients with cerebral aneurysm.

The aim of the present study is to investigate whether glycerol fructose combined with vitamin B6 is beneficial to the postoperative recovery of patients with cerebral aneurysm (CA). A total of 134 patients receiving embolization of CA in the Central Hospital of Wuhan between February, 2013 and June, 2015 and were divided into observation and control groups according to the random number table method, with 67 cases in each group. The control was given vitamin B6 routine treatment, while the observation group received glycerol fructose on the basis of treatment in the control group. The incidence rate of postoperative complications after treatment, Glasgow coma scale (GCS) score, Barthel index score, and neurological fatigue index (NFI) score were compared between the two groups. After treatment, the GCS, Barthel index and NFI scores of patients in the observation were better than those in the control group (p<0.05), and the Barthel index score in the observation group was significantly higher than that in the control group (p<0.01). The mean flow velocity of middle cerebral artery (MCA) in the observation group after treatment was significantly different from that in the control group (p<0.05). As for complications, the incidence rates of postoperative cerebral vasospasm (1.49%), cerebral ischemia (1.49%), hematoma at puncture site (2.98%) and aneurysm rupture and hemorrhage (4.47%) in the observation group were lower than those of cerebral vasospasm (8.95%), cerebral ischemia (7.46%), hematoma at puncture site (8.95%) and aneurysm rupture and hemorrhage (10.44%) in the control group, and the differences were statistically significant (p<0.05). In conclusion, glycerol fructose combined with vitamin B6 can reduce the incidence rate of postoperative complications and improve patients self-care ability and quality of life. Therefore, it is beneficial to postoperative recovery and it is worthy of clinical application.

Effects of different anesthetics on recovery of neurological function after intracranial aneurysm embolization

Objective To compare the effects of different anesthetics on the recovery of neurological function after intracranial aneurysm embolization. Methods One hundred patients of both sexes with aneurysmal subarachnoid hemorrhage, aged more than 18 yr, with body mass index of 18.5-24.0 kg/m2, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ and WFNS grade Ⅰ-Ⅳ, with the thickness of subarachnoid hemorrhage more than 4 cm, were divided into 2 groups (n=50 each) using a random number table: propofol group (group P) and sevoflurane group (group S). After anesthesia induction, group P received intravenous infusion of propofol 100-300 μg·kg-1·min-1, while the end-tidal sevoflurane concentration was maintained at 1.4%-3.5% in group S. Immediately before induction (T0), immediately after the end of induction (T1), immediately after successful embolization of aneurysm (T2) and at 1, 2, 3 and 5 days after surgery (T3-6), central venous blood samples were collected for determination of plasma neuron-specific enolase and S100β protein concentrations by enzyme-linked immunosorbent assay.The development of postoperative cerebral vasospasm and delayed ischemic neurological deficit was recorded.The patients were followed up, and the Glasgow outcome score and occurrence of newly developed cerebral infarction were recorded within 6 months after surgery. Results There was no significant difference in the concentrations of plasma neuron-specific enolase and S100β protein at each time point, incidence of postoperative cerebral vasospasm and delayed ischemic neurological deficit, or Glasgow outcome score and incidence of newly developed cerebral infarction within 6 months after surgery between two groups (P>0.05). Conclusion Propofol and sevoflurane exert no effect on the recovery of neurological function after intracranial aneurysm embolization. Key words: Anesthetics; Recovery of function; Intracranial aneurysm; Embolization, therapeutic

Risk Factors for Postoperative Cerebral Vasospasm After Surgical Resection of Acoustic Neuroma

Cerebral vasospasm is an important cause of morbidity after subarachnoid hemorrhage, but can also occur after resection of acoustic neuroma. This study aimed to identify factors associated with postoperative cerebral vasospasm in patients with acoustic neuroma. This was a retrospective analysis of patients with acoustic neuroma (diagnosed by preoperative magnetic resonance imaging and postoperative pathology) treated between April 2013 and February 2014 in a hospital in China. Patients with other intracranial abnormalities, postoperative vasoactive drug use, or postoperative abnormalities in consciousness, vital signs, blood electrolytes, or arterial blood gases were excluded. The neurilemmoma was removed using the suboccipital retrosigmoid sinus approach, with care taken to minimize bleeding and protect the facial, trigeminal, and lower cranial nerves and brainstem. Flow velocities in the bilateral internal carotid, middle cerebral, and anterior cerebral arteries, assessed with transcranial Doppler ultrasonography before surgery and on postoperative days 1, 3, 5, 7, and 9, were used to detect cerebral vasospasm (mild, 120-140 cm/s; moderate, 141-200 cm/s; severe, >200 cm/s). Factors associated with vasospasm were identified by univariate and multivariate analyses. Forty-three (53.8%) of the 80 patients (36 men) included were diagnosed with cerebral vasospasm: 5 (11.6%) were categorized as mild, 36 (83.7%) as moderate, and 2 (4.7%) as severe. Multivariate analysis showed that younger patient age, larger tumor size, and firm tumor consistency were independently associated with postoperative cerebral vasospasm (P <0.05). Younger patient age, larger tumor size, and firmer tumor consistency were independently associated with postoperative cerebral vasospasm in patients with acoustic neuroma.

Analysis on surgery coordination of refractory intracranial aneurysm in the process of cerebral revascularization therapy

Objective To observe cerebral revascularization procedures in patients with refractory intracranial aneurysm surgery with analysis and prognosis.Methods According the digital table,89 patients with refractory intracranial aneurysm surgery were divided,the control group uesed the intervention operation,and the observation group with vessel revascularization.The complications after the operation,cerebrospinal fluid of red blood cells and pressure indicator,and postoperative quality of life in the two groups were observed.Results Observation group of patients with postoperative cerebral vasospasm (CVS) rate was 20.00％,which was significantly lower than that in the control group 40.00％ (x2 =6.79,P ＜ 0.05).Psychological state (SAS,SDS),self esteem (SES) and other related quality of life evaluation score,the observation group was obviously better than the control group (t =6.27,8.69,7.45,all P ＜ 0.05).Cerebrospinal fluid pressure of red blood cells and obviously than the control group after treatment (t =6.18,8.38,17.82,0.57,all P ＜ 0.05).Conclusion Cerebral revascularization in patients with refractory intracranial aneurysm has better reduce operation and operation complications as well as the ability to relieve mental depression,improve the quality of life,is worth the clinical promotion. Key words: Cerebral revascularization; Interventional embolization; Intracranial aneurysms

Imaging classification of middle cerebral artery aneurysms and its value for clipping surgery: a single -center retrospective analysis of 134 cases

Objective To introduce a imaging classification of middle cerebral artery aneurysms (MCAAs) based on angiography and to explore its guidance value for the clipping surgery.Methods A total of 168 aneurysms were found in 134 patients,of which 143 were MCAAs.According to the direction of aneurysmal projections,they were classified into 4 types:58 point to the temporal side,29 to frontal,52 to the posterior superior part of Sylvius cistern,and 4 to the posterior inferior part of Sylvius cistern. 141 aneurysms were successfully direct clipped.Results According to Glasgow outcome score ( GOS),111 patients (82.8％) had an excellent clinical outcome of GOS 5,14 ( 10.5％ ) GOS 4,4(3.0％ ) GOS 2 ～ 3 and 5 deaths (3.7％,GOS 1 ).Conclusions Preoperative imaging classification of MCAAs may play an important guiding role to the microsurgical treatment which could provide individually optimal strategies for aneurysm dissecting and neck clipping,and could reduce postoperative cerebral vasospasm and improve the therapeutic effect of surgical treatment. Key words: Middle cerebral artery aneurysms; Microsurgery; Imaging classification

Cerebral vasospasm following temporal lobe epilepsy surgery

Selective amygdalohippocampectomy (AHE) has been associated with postoperative cerebral vasospasm (CVS) in patients with medically intractable temporal lobe epilepsy. The incidence in temporal lobe resection (TLR) is unknown. This retrospective cohort study evaluates the incidence of and risk factors for the development of CVS in patients with TLR and AHE. A total of 119 patients were included between 1998 and 2009. All patients were evaluated by standardized preoperative and postoperative transcranial Doppler sonography (TCD) evaluations and neurologic examinations. Postoperative CT scans were evaluated by an independent radiologist and the volume of bleeding within the resection cavity was quantified. Of 107 patients with longitudinal TCD data, 35 (32.7%) developed postoperative CVS. The incidence of CVS did not differ between patients with TLR and AHE. CVS was associated with female gender and a higher bleeding volume in the postoperative CT scan (p = 0.035 and 0.046). Patients with CVS showed a significantly higher incidence of postoperative neurologic signs and symptoms (48.6%) compared to patients without CVS (25%, p = 0.015). The mean length of stay was significantly prolonged in patients with diffuse CVS compared to patients with localized CVS or no CVS (28.8 ± 10.9, 24.2 ± 6.6, and 18.2 ± 6.1 days, p < 0.001). CVS is a frequent complication of surgery for temporal lobe epilepsy irrespective of the resection method. Important risk factors for the development of postoperative CVS are female gender and a higher amount of bleeding in the postoperative CT. Patients with CVS more frequently have neurologic signs and symptoms resulting in prolonged hospital stay.

Unilateral neurogenic pulmonary oedema: An unusual cause for post-operative respiratory dysfunction following clipping of ruptured intracranial aneurysm

A variety of central nervous system lesions like stroke, subarachnoid haemorrhage, trauma and seizure activity can result in neurogenic pulmonary oedema (NPE). Unilateral neurogenic pulmonary oedema is very rare. There are no reports of unilateral NPE with aneurysmal vasospasm. We present the case of a 55-year-old female who developed respiratory distress with unilateral pulmonary oedema and mild left ventricular dysfunction in the context of postoperative cerebral vasospasm following clipping of ruptured intracranial aneurysm. Neurogenic pulmonary oedema should always be in the differential diagnosis when patients with presumed neurogenic pathology develop respiratory compromise. The diagnosis of unilateral neurogenic pulmonary oedema requires a high index of suspicion. Early initiation of supportive treatment results in good outcome.

Cerebral blood flow and tissue oxygenation monitoring during aneurysm surgery

Regional cerebral blood flow may be compromised during aneurysm surgery. This may occur during vessel occlusion by temporary clips or result from malposition of the definitive aneurysm clip. Post-operative cerebral vasospasm may also compromise cerebral blood flow and is an important cause of morbidity. This study addresses the need for a sensitive indicator of compromised cerebral function during aneurysm surgery by measuring brain tissue oxygenation and laser Doppler flow. Four patients were studied, all of whom had ruptured middle cerebral artery aneurysms. Brain tissue oxygenation measurements were made with a closed polarographic sensor placed in the ipsilateral cerebral hemisphere to the aneurysm. A laser Doppler flow probe and intracranial pressure monitor were similarly placed. The data were simultaneously processed using multimodality recording monitoring. The monitoring was continued during the postoperative period and totalled over 190 hours. Data were analysed as specific events and as trends. Initial tissue oxygen levels were low but improved in all cases as the intracranial pressure was reduced. This effect was independent of the cerebral perfusion pressure. Laser Doppler flow provided an indicator of compromised brain function and tissue oxygenation an indicator of established ischemia. [Neural Res 1998; 20 (Suppl 1): 544-547]

The calcium entry blocker nimodipine improves the quality of life of patients operated on for cerebral aneurysms. A 5-year follow-up analysis.

Between 1981 and 1985 at our clinic 204 consecutive patients underwent surgical repair of cerebral aneurysms after spontaneous subarachnoid hemorrhage. Of these 113 were treated with Nimodipine, a predominantly cerebrovaskular-active substance. The preoperative condition according to Hunt and Hess (9), the locations of the aneurysms, and the ages of the two groups of patients were directly comparable. The incidence of postoperative cerebral vasospasm was however higher in the Nimodipine group (49%) than in the control group (33%). Retrospectively we analyzed the progress of the patients as to their neurological, intellectual, and social function for up to five years after the operation. Mortality and morbidity in the Nimodipine group amounted to 10% and 7% respectively, in the group without Nimodipine 20% and 17% respectively (p less than 0.001). Of the Nimodipine patients, 72% showed excellent neurological outcome, with 73% intellectually, and 72% completely resocialized, as compared to 53% in the control group with an excellent neurological outcome, 39% intellectually intact (p less than 0.0001, and 52% completely resocialized (p less than 0.01). These results suggest that Nimodipine not only increases cerebral blood flow, but also protects brain tissue from ischemic damage.

The 5-hydroxytryptamine antagonist ketanserin inhibits the vasoconstrictor activity of per-operative CSF, from subarachnoid haemorrhage patients, on isolated tissues.

Peri-aneurysmal CSF was obtained at operation from 13 patients with subarachnoid haemorrhage from ruptured intracranial aneurysms. The 5-hydroxytryptamine antagonist ketanserin inhibited contractions of isolated human intracranial arteries, elicited by this CSF. The presence of 5-HT in CSF was confirmed by high performance liquid chromatography. The use of ketanserin in the therapy of postoperative cerebral vasospasm is discussed.

Incidence and neurological significance of postoperative cerebral vasospasm. A study of 80 consecutive cases with clipped saccular aneurysms.

The pre- and postoperative angiograms of 80 patients with clipped cerebral aneurysms were reviewed and vasospasm was classified, according to the extent of the angiospasm, into three types (type I diffuse, widespread spasm, type II multisegmental vasoconstriction, type III local angiospasm). The neurological Status of the patients at the time of angiography and Operation was correlated with the clinical grading System of Hunt and Hess. Postoperative vasospasm was found in 40% of the cases. There was a remarkably close correlation between the incidence of severe spasm (type I) and the time which had elapsed from haemorrhage to Operation: Almost all patients who developed diffuse extensive angiospasm after Operation (most of them had no pre-operative spasm or only minor, initially local, vasoconstriction) had been operated on within the first eight days after subarachnoid haemorrhage. Those cases which had angiospasm pre-operatively but no longer had vasospasm after Operation had all undergone Operation later than the first week. Patients with local or multisegmental angiospasm are more often grade III or IV within the first week than patients with equal spasm postoperatively two or three weeks after initial SAH. This suggests that in the early phase after rupture of an aneurysm factors other than local vasoconstriction per se must play a pathogenetic role. These factors have no influence or only a minor significance in the later weeks.

Intracranial compliance during the post-operative period after surgery for intracranial aneurysms.

Generalised post-operative cerebral vasospasm is a major factor in delineating poor operative results following direct ruptured intracranial aneurysms. Continuous monitoring of intracranial pressure seems to be particularly helpful on such occasions, and intracranial compliance determination as well. High intracranial compliance values suggest that even small intracranial volume increases may induce rapid intracranial pressure and situations likely to produce neurological deterioration.