How often is a perimesencephalic subarachnoid haemorrhage CT pattern caused by ruptured aneurysms?

SummaryBackground Angiography is usually recomended in perimesencephalic subarachnoid haemorrhage (PM SAH) to rule out a basilar artery aneurysm. However it is not known how often aneurysms are found among patients with a CT pattern of PM haemorrhage or the frequency of this CT pattern after rupture of posterior circulation aneurysms.Method CTs of all SAH caused by posterior circulation aneurysms admited from 1/85 to 12/92 where reviewed by two examiners. Late (>72 h) examinations were excluded. The remaining CTs were classified in perimesencephalic (PM) or non PM.Results 81 posterior circulation aneurysms were collected. Only one PM-like CT pattern was found, due to ruptured posterior communicating artery aneurysm (1.3%; 95% Cl (confidence intervals)=.03–6.7%). During the same period 37 PM SAH with negative angiographic results were admited. The likehood of finding an aneurysm in a patient with an early CT showing a PM distribution of haematic densities was 2.7% (95% Cl=.07–14%).Conclusion Although the probability of finding an aneurysm in a SAH patient with a PM CT pattern is low, a complete 4-vessel angiogram must be obtained.     

Surgical management of ruptured aneurysms in the eighth and ninth decades

Summary ?Background. The surgical management of elderly patients with aneurysmal subarachnoid haemorrhage (SAH) is controversial. The present study was performed to more clearly define issues facing elderly SAH patients undergoing surgical repair of their aneurysms. Method. Between 1990 and 2000, 100 patients, aged 70 years or older, were managed consecutively with aneurysmal surgical repair at Verona City Hospital. Ninety-seven of these were analysed with regard to age, clinical grade on admission, radiological features, and specific management components (3 patients were excluded from further analysis because of inadequate follow up data). Surviving patients were followed up for a minimum of 6 months and clinical outcome was assessed. Findings. Hydrocephalus requiring permanent CSF diversion occurred in 44% of cases surviving beyond 10 days from their SAH. The development of hydrocephalus requiring shunting was delayed more than 6 weeks in 7% of these cases. Medical complications occurred in 22% of cases. Clinical grade of haemorrhage (p<0.001), early hydrocephalus requiring ventriculostomy (p=0.003) and the development of medical complications (p=0.03) were significantly associated with poor outcome. Clinical vasospasm was not a major determinant of outcome in this group. The need for permanent CSF diversion was significantly associated with increasing age (p=0.03), intraventricular haemorrhage (p<0.001), early hydrocephalus requiring ventriculostomy (p=0.003) and the development of medical complications (p=0.05). Interpretation. Elderly patients experience a different range of complications following aneurysmal subarachnoid haemorrhage than their younger counterparts. Clinicians should remain alert to the development of hydrocephalus, especially of delayed onset. Published online June 11, 2003     

Subarachnoid haemorrhage of unknown aetiology

Summary The authors review the literature on subarachnoid haemorrhage of unknown aetiology (SAHUE) and analyze a personal series of 212 patients diagnosed as SAHUE. These patients represent 30% of all cases of primary SAH admitted over a 14.5 year period.The age, sex, antecedents and initial clinical presentation of patients with SAHUE were indistinguishable from those of patients with subarachnoid haemorrhage due to ruptured aneurysm (SAHRA). However, the present series of SAHUE compare favourably with both a personal and a previously reported series of SAHRA insofar as clinical grade on admission (94% of patients in grades I–II of Botterell), presence of blood on CT (51%), vasospasm (5%), ischaemic deficits (3.3%), persistent hydrocephalus (3.5%), rebleeding (6%) and fatal result (3.9%) are concerned.The amount of blood on CT scan in our patients with SAHUE was associated with a significantly higher incidence of brain ischaemia and hydrocephalus but did not correlate with the Botterell grade on admission or final outcome, which were good in the majority of cases regardless of the presence or not of visible cisternal haemorrhage. The results of the present series confirm that the final prognosis of patients with primary SAH showing normal four-vessel cerebral angiography is essentially favourable.     

Hydrocephalus: comparison of clipping and embolization in aneurysm treatment

OBJECT: In this retrospective study conducted at Atkinson Morley's Hospital and Middlesbrough General Hospital, the authors analyzed 100 matched patients who had suffered subarachnoid hemorrhage (SAH) to determine whether the technical procedure by which aneurysms are treated affects the development of chronic hydrocephalus. METHODS: Four hundred seventy-five patients presented with SAH between 1995 and 1998. Exclusion criteria included posterior circulation aneurysms, multiple aneurysms, electively clipped or embolized aneurysms, angiographically undetected SAH, patients who died within 1 month of neurosurgical intervention, and patients with the same aneurysm location but a different Fisher grade. The authors matched 50 patients who underwent embolization of their aneurysms with another 50 who had similar Fisher grades and aneurysm types and underwent clipping of their aneurysms. The maximum incidence of ruptured aneurysms occurred in patients who were between 41 and 60 years of age, with women preponderant in both study groups. In each group, 27 patients had anterior communicating artery aneurysm, 13 had posterior communicating artery aneurysm, seven had middle cerebral artery aneurysm, and three had internal carotid artery aneurysm. The lesions in three patients in each group were Fisher Grade I, in 23 patients they were Fisher Grade II, in 14 they were Fisher Grade III, and 10 patients had Fisher Grade IV SAH. Nine patients among those with clipped aneurysms and eight of the patients who underwent embolization had hydrocephalus for which they needed intervention. These interventions included lumbar puncture, ventricular drainage, and ventriculoperitoneal (VP) shunt placement; three patients in each group needed VP shunt placement. CONCLUSIONS: The technical procedure used to treat aneurysms, whether clipping or embolization, does not significantly affect the development of chronic hydrocephalus. However, a larger sample of patients is needed for accurate comparisons and stronger conclusions.     

One-year outcome in early aneurysm surgery: a 14 years experience

Summary In a consecutive series of 1150 patients with cerebral aneurysms diagnosed in our department by angiography or autopsy between the years 1977–1990, 1007 patients underwent definitive operative treatment of their aneurysms mainly by early surgery. More than half (55%) were operated on during the first three days after subarachnoid haemorrhage (SAH), and more than three quarters (77%) during the first week. The surgical mortality at 30 days was 9%; at one-yearfollow-up 13% had died. The total management mortality was 22%. The 618 patients presenting in Hunt and Hess Grades I–II had a 4% mortality, and 90% had an independent life at follow-up; 270 Grade III patients hat a 19% mortality and 68% were independent. There were 99 patients operated on in Grades IV–V with a 46% mortality and 30% were independent. Age of the patient and size of the aneurysm were strongly related to outcome; however, many of the giant aneurysms were operated on as an emergency because of large intracerebral haematomas. Best results were obtained in the anterior communicating artery (ACA) area; the lowest rate of useful recoveries was in the vertebro-basilar artery (VBA) area (71%). Early surgery did not prevent delayed ischaemic deficits.During the first 72 hours patients in Grades I–III can be operated on safely with good results. The results in Grades IV–V are poor, and we suggest that only cases with large haematomas or considerable hydrocephalus or those improving should be operated on in the first days after SAH, with limited hopes of functional recovery.     

Ruptured intracranial dissecting aneurysms: management considerations with a focus on surgical and endovascular techniques to preserve arterial continuity

Background. The present retrospective analysis was undertaken to review an institutional experience with 13 intracranial dissecting aneurysms as source of subarachnoid haemorrhage (SAH) among a total of 585 ruptured intracranial aneurysms. Methods and results. In 6 patients the vertebral artery (VA) was affected, in 2 patients the basilar artery (BA), in 3 the internal carotid (ICA), in 1 the middle cerebral (MCA) and in 1 the postcommunicating (A2) segment of the anterior cerebral artery (ACA). Maintaining arterial patency was aimed at in all patients. Tangential clipping or circumferential wrapping were used as surgical methods. Endovascular stenting and/or coiling was applied in 2 instances. Four of the 6 VA dissecting aneurysms underwent surgical exploration between 1 and 22 days after haemorrhage. Two patients were in WFNS grade V and died subsequently with the aneurysms untreated, one after rehaemorrhage. In the patients with secured VA aneurysms the postoperative course was uncomplicated with the exception of additional caudal cranial nerve injury in 1 instance. Both BA aneurysms were initially treated by endovascular methods. In the first patient incomplete packing with Gugliemi detachable (GDC) coils was achieved. Follow-up angiography 6 months later showed growth and coil compaction and subsequent wrapping with Teflon fibres resulting in angiographic stabilization. The other BA aneurysm was treated by a combination of a coronary stent and GDC coils. The 3 dissecting ICA aneurysms were all explored surgically. In only 1 instance ICA continuity could be preserved by wrapping, in the other 2 cases a major portion of the vessel wall disintegrated upon removal of the surrounding clot. The only ACA dissecting aneurysm, on A2, was successfully treated with a Dacron cuff. In the single patient with a MCA aneurysm, a decision for conservative management was taken, because neither a surgical nor an endovascular solution was seen as a possibility that did not risk occlusion of lenticulostriate branches. The patient suffered a fatal rehaemorrhage 4 weeks later at her home. Conclusions. The reported experience suggests that in Western countries also dissecting aneurysms are an occasional source of SAH. The outcome in our conservatively managed patients confirms the poor prognosis of conservative management. Wrapping and endovascular stent based methods can achieve stabilization of the dissected artery without sacrificing the artery. Results of treatment appear to depend largely on the location of the dissecting aneurysm.     

Relation between size of aneurysms and risk of rebleeding in patients with subarachnoid haemorrhage

Summary Background and purpose. Few risk factors have been identified for rebleeding in patients with subarachnoid haemorrhage. We studied whether size of aneurysm after rupture is a risk factor for rebleeding. Since intracranial aneurysms develop during life and may therefore be larger at an older age, we also assessed whether age confounds a relation between size and rebleeding. Methods. We studied all patients with aneurysmal subarachnoid haemorrhage admitted between 1995 and 2000. Since 1995 CT-angiography is obtained in all patients on admission. Patients were followed until rebleeding, operation, discharge or death. For the relation between size and risk of rebleeding we used Cox proportional hazards modelling. Results. We included 354 patients. Rebleeding occurred in 22 (30%) of the 73 patients with a large (>10 mm) aneurysm, and in 68 (24%) of the 281 patients with a small (≤10 mm) aneurysm (hazard ratio for large aneurysms 1.6 (95% confidence interval [CI] 1.0–2.6)). Within the first three days rebleeding occurred in 14 (19.2%) patients with a large aneurysm and in 25 (8.9%) patients with a small aneurysm (hazard ratio 2.4 (95% CI 1.2–4.5)). After adjustment for age, all hazard ratios remained essentially the same. Conclusion. Patients with large aneurysms have a higher risk for rebleeding, in particular within the first three days after the initial haemorrhage. This increased risk is independent of age.     

Aneurysm of the internal auditory artery: Our experience and review of the literature

Summary The aneurysms of the internal auditory artery (IAA) situated distal from anterior inferior cerebellar artery (AICA)-IAA junction, are extremely rare lesions. A case of distal aneurysm of IAA is presented causing subarachnoid haemorrhage (SAH) and complete ipsilateral deafness. After the neurosurgical treatment the hearing of the patient definitely improved. The literature of distal aneurysms of AICA is reviewed focusing on the clinical features of these malformations, causing cerebello-pontine angle (CPA) symptoms with or without SAH.     

Early CT features of ruptured cerebral aneurysms of the posterior cranial fossa

This report describes our retrospective evaluation of CT features of the acute phase in 34 cases of ruptured cerebral aneurysms of the posterior cranial fossa. The results are as follows. 1. Examination of cisternal haematoma distribution revealed that SAH had extended to the supra- and infratentorial cisterns in 28 cases (82%). There were only 6 cases (18%) in which SAH was confined to the posterior cranial fossa only but even when there was subarachnoid haematoma in both the supra- and infratentorial cisterns, thick haematomas were seen at the periphery of the brain stem. In cases of vertebral artery-posterior inferior cerebellar artery aneurysms (VA-PICA AN), haematomas in the ambient cistern were thicker on the aneurysm side. In addition, in cases of basilar artery-bifurcation (BA-Bifurcation AN) and basilar artery-superior cerebelli artery aneurysms (BA-SCA AN), there were many thick, high-density haematomas in the interpeduncular cistern. 2. The rate of intracerebral haemorrhage was extremely low (1 patient). 3. The rate of intraventricular haemorrhage was high, and these haemorrhages demonstrated a reflux pattern. 4. The rate of hydrocephalus was high (76.5%) in comparison with that noted in association with SAH due to the rupture of anterior circulation aneurysms.     

Does nimodipine influence sex difference in outcome after aneurysmal subarachnoid haemorrhage?

Summary Before nimodipine was introduced as a standard treatment in patients with aneurysmal subarachnoid haemorrhage (SAH) females had a significantly poorer outcome which might be due to a higher frequency of delayed cerebral ischaemia (DCI). We evaluated the overall outcome with regard to gender in 188 consecutive patients with a verified ruptured intracranial aneurysm treated with nimodipine. The only significant differences concerning prognostic factors between the sexes were a higher frequency of SAH at the primary CT in females (p<0.05) and a higher frequency of middle cerebral artery aneurysms in females (p<0.01). These factors affect the outcome in females unfavourably. However, contrary to previous studies, we found no difference in overall outcome after three months between the sexes in this clinical material. Our observation can be explained by a positive effect of nimodipine on DCI.     

Characteristics and management of ruptured distal middle cerebral artery aneurysms

Summary Objective. Distal middle cerebral artery (dMCA) aneurysms are very rare with a reported frequency of 2–6%. Typically, patients with ruptured distal MCA aneurysms have poor clinical outcomes because often there is both a subarachnoid haemorrhage (SAH) and an intracerebral haematoma (ICH). The goals of this study were to identify the characteristics of the distal MCA aneurysms and evaluate the optimal treatment for a good outcome. Methods. The clinical, neuroradiological and operative records of 8 patients with a ruptured distal MCA aneurysm who underwent surgical management were reviewed retrospectively. The outcomes were presented according to the Glasgow Outcome Scale (GOS). Results. The clinical characteristics of the patients with ruptured dMCA aneurysms included the following: (1) a fusiform appearance in five out of eight (63%) patients. (2) Mean aneurysm size of 9.4 mm (range 2–35 mm). (3) The location being M2 (insular segment) in three, M2-3 junction in three, and M3 (opercular segment) in two patients. (4) Brain CT images revealed both SAH and an ICH in six of eight (75%) patients with the mean size of the ICH being 10 cc (range 5–25 cc). (5) Re-bleeding occurred in four out of eight (50%) of patients. All patients underwent early surgical treatment and the procedures used for surgical repair were, clipping in five patients, trapping in two, and trapping with end-to-end bypass surgery in one patient. Clinical outcomes were poor in two patients (death) due to severe brain swelling. Conclusions. In this study, dMCA aneurysms had a fusiform shape and a high re-bleeding rate; if ruptured, there was generally ICH and SAH. A good clinical outcome was associated with adequate control of brain swelling and early surgery to prevent re-bleeding.     

Shunt-dependent hydrocephalus after subarachnoid haemorrhage and aneurysm surgery: Timing of surgery is not a risk factor

Summary Early hydrocephalus is a risk factor of shunt-dependent late hydrocephalus (SDHC). In the CT era 1980–1990 we had 835 consecutive patients operated on because of aneurysm and subarachnoid haemorrhage (SAH); 294 had an early hydrocephalus and 67 finally required a shunt. There were 14 patients with normal early CT and SDHC, in all 81 patients needed a shunt (10%). Patients with shunt did worse, they were older (53 vs 49) than the non-shunted group and there was a female preponderance.Pre-operative Grade correlated significantly with the need for a shunt operation; no one in Grade I developed SDHC, incidence in Grades III and IV was high (18% and 10%, respectively). Location was important; in vertebrobasilar area 28% and in anterior communicating area 14% but in middle cerebral area only 4% of the patients had SDHC.The amount of cisternal bleeding correlated significantly with SDHC; in 155 patients with non detectible or minimal cisternal blood only one developed SDHC, with severe cisternal bleeding the incidence was 16%. Ventricular bleeding increased the risk of SDHC, but intracerebral haematoma did not.Timing of surgery had no correlation with the risk of SDHC. Postoperative complications, haematomas and infections increased the risk of late SDHC. Delayed ischaemia correlated with the risk, but so did the treatment with nimodipine. Severe bleeding was the common predictor for the risk of SDHC. Location of the bleeding and postoperative problems are the other major causes. Outcome is, however, not so gloomy; 54% of patients with SDHC are independent one year later.     

Superoxide dismutase activity in cisternal cerebrospinal fluid after aneurysmal subarachnoid haemorrhage

Summary It has been recognised that the level of superoxide dismutase (SOD) significantly increases in CSF as the result of cerebral ischaemic damage. The aim of this study was to correlate the CSF levels of SOD enzymatic activity to the patterns of subarachnoid haemorrhage with regards to ischaemic complications due to vasospasm.A series of 78 patients operated on for intracranial aneurysms was studied; all patients were monitored with serial TCD measurements every second day after SAH. CSF samples were obtained at surgery by cisternal puncture of the subarachnoid cistern nearest to the aneurysm. SOD activity was assayed spectrophotometrically.Mean cisternal CSF level of SOD in 12 control cases (12.99±2.33 U/ml) is significantly higher (p < 0.01) than in 26 patients operated on between day 1 and 3 from last SAH episode (4.44±0.7 U/ml) and in 40 patients treated by delayed surgery (7.64±0.92 U/ml). In 13 patients presenting neurological deterioration related to arterial vasospasm mean cisternal SOD level was 12.23±1.86 U/ml; in 27 cases without vasospasm mean level was 5.43±0.7 U/ml (p < 001).The present results suggest that (a) cisternal CSF levels of SOD significantly decreases after SAH, probably in relation to an impaired synthesis in the brain compartment and that (b) a substantial elevation of SOD levels is evident in patients suffering ischaemic complications vasospasm-related. Biochemical events in the brain compartment could influence the expression and release of anti-oxidant enzymes in CSF after SAH.     

Value of the quantity and distribution of subarachnoid haemorrhage on CT in the localization of a ruptured cerebral aneurysm

Summary ¶Background. Computed tomography (CT) is the gold standard for detecting subarachnoid haemorrhage (SAH) and digital subtraction angiography (DSA) for visualising the vascular pathology. We studied retrospectively 180 patients with subarachnoid haemorrhage (SAH) who underwent first non-enhanced computed tomography (CT), then digital subtraction angiography (DSA) and finally operative aneurysm clipping. Our aim was to assess if the location of the ruptured aneurysm could be predicted on the basis of the quantity and distribution of haemorrhage on the initial CT scan. Methods. 180 patients with SAH were retrospectively studied. All the CT and DSA examinations were performed at the same hospital. CT was performed within 24 hours after the initial haemorrhage. DSA was performed after the CT, within 48 hours after the initial haemorrhage. Two neuroradiologists, blind to the DSA results, analysed and scored independently the quantity and distribution of the haemorrhage and predicted the site of the ruptured aneurysm on the basis of the non-enhanced CT. DSA provided the location of the ruptured aneurysm. All the patients were operated upon, and the location of the ruptured aneurysm was determined. Findings. The overall reliability value (-value) between the two neuroradiologists for locating all ruptured aneurysms was 0.780. The corresponding value for the right MCA was 0.911, that for the left MCA 0.877 and that for the AcoA 0.736. Not all of the -values were calculated, either because the location of the rupture was constant or because the number of ruptures in the vessel was too small. Subarachnoid haemorrhage with a parenchymal hematoma is an excellent predictor of the site of the ruptured aneurysm with a statistical significance of p=0.003. Interpretation. The quantity and pattern of the blood clot on CT within the day of onset of SAH is a reliable and quick tool for locating a ruptured MCA or AcoA aneurysm. It is not, however, reliable for locating other ruptured aneurysms. Subarachnoid haemorrhage with a parenchymal hematoma is an excellent predictor of the site of a ruptured aneurysm.Published online July 23, 2003     

Vasospasm due to massive subarachnoid haemorrhage — a rat model

Summary Although the pathophysiology of chronic cerebral vasospasm following subarachnoid haemorrhage (SAH) is still unclear, it is certain that the amount of subarachnoid blood is predictive of the severity of cerebral vasospasm. Accordingly, massive subarachnoid haemorrhage (>0.5 ml) was induced in adult rats via direct injection into the cisterna magna. Compared to other previously published models of experimental SAH in rats a much larger amount of blood was injected.The basilar artery was exposed 72 hours post subarachnoid haemorrhage and photographed under controlled conditions. The diameter of the artery was assessed by an image analyzer. A 50% reduction in diameter was found in 25 rats subjected to SAH as compared to 9 control rats and 4 rats with intracisternal saline injection.We conclude that when massive subarachnoid haemorrhage is induced, and direct measurements of the basilar artery are made, the rat can be used as a reliable model for investigation of SAH induced arterial vasospasm.     

Ruptured de novo intracranial aneurysms

Summary Objective. We describe the actual state of ruptured de novo intracranial aneurysms to contribute to a guideline of follow-up for the patients with treated intracranial aneurysm.Methods. The authors retrospectively investigated 12 cases drawn from 483 consecutive cases of aneurysmal subarachnoid hemorrhage at our institute over a period of 22 years, in which a previously undemonstrated (hence de novo) intracranial saccular aneurysm formed and ruptured after successful treatment of a prior aneurysm.Findings. The 12 cases constitute 2.5% of the 483 patients who left our hospital alive. Eleven cases were females and one was a male with a mean age of 55.7 years (range 29–75) at the first subarachnoid haemorrhage (SAH) and an interval between the first and the second rupture of 10.7 years (range: 2.6–23.8, standard deviation: 6.86, 95% confidence interval: 6.39–15.1). Four cases did not have risk factors such as hypertension, family history, smoking, multiple aneurysms, and moyamoya disease. None of these ruptured de novo aneurysms was at the same location as the original lesion. One-third (4 cases) of the de novo lesions in our series were found on the opposite side to each prior lesion.Interpretation. For not only young but also elder patients with a treated aneurysm (from the fifth decade to the sixth), especially for women, late angiography or alternative modalities of less-invasive examination should be considered. To detect de novo intracranial aneurysms before rupture, the search for a de novo aneurysm should be performed within 6.39 years after a previous examination that shows an aneurysm to be nonexistent, in view of the 95% confidence interval of the mean time to de novo aneurysmal rupture (6.39–15.1 years). If applied this survey, 75% (8 cases of 12 cases) of our de novo aneurysms would be detected before rupture.     

Carotid Rete Mirabile Presenting Subarachnoid Haemorrhage. Report of Two Cases

Carotid rete mirabile (CRM) consists of arterial channels between the internal and external carotid arteries in some lower mammals. It is a very rare pathological condition in humans. We report two patients who presented with clinical signs of subarachnoid haemorrhage (SAH). Their sudden-onset SAH was thought to have been due to rupture of cerebral aneurysms, however, angiograms revealed an abnormal vascular network around the cavernous sinus. To our knowledge, 2 of 7 reported patients with CRM presented with SAH, however, only one of these patients had a probable cerebral aneurysm. We suggest that in patients with CRM, the rupture of anastomosing vessels be a probable cause of SAH.     

Subarachnoid haemorrhage of unknown origin

Summary This study concerns 64 patients with angiographically negative subarachnoid haemorrhage (SAH) hospitalized in the period 1970–1982. Requisites for inclusion in the study were adequate angiographic demonstration of the carotid and vertebrobasilar systems and no clinical signs of spinal SAH or spontaneous intracerebral haematoma. The clinical data on the 64 cases confirm the close similarity, except for the prognostic factors, between angiographically negative SAH and SAH secondary to rupture of an intracranial saccular aneurysm. The study underlines the benign character of the clinical course and of the medium and long-term prognosis of the condition under study. In view of this, the hypothesis advanced sometime ago relating angiographically negative SAH to the rupture of microaneurysms (Ø<2 mm) of the large cerebral arteries with subsequent complete repair of the artery wall, or to the spontaneous thrombosis of intracranial saccular aneurysms, with the possibility of subsequent recanalization and risk of fresh rupture, would appear to be a reasonable one.     

Efficacy of Lumbo-Peritoneal Versus Ventriculo-Peritoneal Shunting for Management of Chronic Hydrocephalus Following Aneurysmal Subarachnoid Haemorrhage

Summary ? Background. The clinical usefulness of lumboperitoneal (LP) shunts in selecting patients with communicating hydrocephalus after aneurysmal subarachnoid haemorrhage (SAH) was compared with that of ventriculoperitoneal (VP) shunts.  Method. Chronic hydrocephalus was defined as clinically and radiographically demonstrated hydrocephalus which lasted 3 weeks or longer after the original haemorrhage and which required shunting. Indications for a CSF shunt were assessed on the basis of neurological symptoms and signs, CT findings, and isotope cisternogram findings. The patients were treated with either LP or VP shunts. A significant response to shunting was defined as an improvement of function to a higher grade. The functioning of the shunt was evaluated by the location of the catheter on x-ray studies, CT features, and isotope cisternograms. The operation groups were checked for comparability of demographic and clinical variables including age, Fisher grade, hypertension, vasospasm, shunt interval, preshunt functional grade, and CT findings. A comparative analysis of the outcome was carried out between the two operation groups.  Findings. Fifty-six patients underwent shunt placements (LP shunts: 22, VP shunts with medium pressure valve: 2, VP shunts with high pressure valve: 32). There was no statistically significant difference in patient demographics and clinical characteristics between the patients with LP shunts and those with VP shunts. A follow-up time of 3 months to 8 years revealed clinical improvement in 11 cases (50.0%) of patients with LP shunts and 31 cases (91.1%) in VP shunts was seen (Fisher's exact test, P<0.005).  Interpretation. These findings suggest that VP shunts are a better choice of treatment than LP shunts in treating chronic hydrocephalus after aneurysmal SAH.     

Proximal clipping of dissecting intracranial vertebral aneurysm — effect of balloon Matas test with neurophysiological monitoring

Summary A case of repeated subarachnoid haemorrhage (SAH) caused by rupture of a dissecting intracranial vertebral aneurysm is reported. The clinical manifestations, angiographic findings, pre-operative assessment with neurophysiological monitoring, and surgery are presented. A review of the literature suggests that this type of intracranial aneurysm is being recognized with increasing frequency in SAH and fatality, and therefore exploration and treatment of vertebrobasilar (V-B) dissecting aneurysms is necessary. We emphasize that a balloon Matas test with monitoring of somatosensory evoked potentials (SEP), auditory brain stem responses (ABR), and its wedge pressure in occluding the vertebral artery before operation are objective assessments of treatment for dissecting intracranial vertebral aneurysm.