Multimodality treatment of intracranial arteriovenous malformations in South Island, New Zealand

Treatment of intracranial arteriovenous malformations is complex and multidisciplinary. This article presents the treatment model utilized in Christchurch, New Zealand which provides cerebrovascular surgery and interventional neuroradiology to the entire south island (approximate population of 1.1 million). A total of 40 patients treated over a 10 year period (2004-2014) are analysed here. Nine patients were managed surgically and complete resection was achieved in 100% of cases. Permanent mortality was 0% and permanent morbidity was 22% however median mRS improved from 3.0 preoperatively to 1.0 at follow up. Embolisation was utilized in 31 patients (mean age 40), of which 45% presented with haemorrhage, 39% with seizures, 10% with a headache only, and 6% with a deficit. None were found incidentally. The Spetzler-Martin grade 1 cases accounted for 10% of the cohort, 23% were grade II, 42% grade III, 23% grade IV and 3% grade V. A single aneurysm was present in 42% of cases, and multiple in 13%. The nidus was obliterated in 9.6% of cases with a morbidity rate of 6.5% and mortality rate of 3%. Modified Rankin scale improved marginally from 0.9 at diagnosis to 0.88 at final follow up (mean 22 months). There were no cases of recanalization. The total nidus obliteration rate using our algorithm of surgery alone for small accessible lesions, then staged embolization for larger lesions with adjuvant radiosurgery reserved for cases with residual nidus, was 50%.

Early Magnesium Treatment After Aneurysmal Subarachnoid Hemorrhage: Individual Patient Data Meta-Analysis

BACKGROUND AND PURPOSE

Delayed cerebral ischemia (DCI) is an important cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). Trials of magnesium treatment starting <4 days after symptom onset found no effect on poor outcome or DCI in SAH. Earlier installment of treatment might be more effective, but individual trials had not enough power for such a subanalysis. We performed an individual patient data meta-analysis to study whether magnesium is effective when given within different time frames within 24 hours after the SAH.

METHODS

Patients were divided into categories according to the delay between symptom onset and start of the study medication: <6, 6 to 12, 12 to 24, and >24 hours. We calculated adjusted risk ratios with corresponding 95% confidence intervals for magnesium versus placebo treatment for poor outcome and DCI.

RESULTS

We included 5 trials totaling 1981 patients; 83 patients started treatment<6 hours. For poor outcome, the adjusted risk ratios of magnesium treatment for start <6 hours were 1.44 (95% confidence interval, 0.83-2.51); for 6 to 12 hours 1.03 (0.65-1.63), for 12 to 24 hours 0.84 (0.65-1.09), and for >24 hours 1.06 (0.87-1.31), and for DCI, <6 hours 1.76 (0.68-4.58), for 6 to 12 hours 2.09 (0.99-4.39), for 12 to 24 hours 0.80 (0.56-1.16), and for >24 hours 1.08 (0.88-1.32).

CONCLUSIONS

This meta-analysis suggests no beneficial effect of magnesium treatment on poor outcome or DCI when started early after SAH onset. Although the number of patients was small and a beneficial effect cannot be definitively excluded, we found no justification for a new trial with early magnesium treatment after SAH.

Non-surgical primary treatment of chronic subdural haematoma: Preliminary results of using dexamethasone

From a series of 112 cases (64 men and 48 women, aged 37 - 91 years) of chronic subdural haematoma (CSDH) in a 2-year period from January 1998 to December 1999, we have prospectively studied a group of 30 patients, who were managed non-operatively: 26 patients were treated with dexamethasone (Group 1) and four patients expectantly (Group 4). Nineteen patients (73%) from Group 1 were confused or had focal neurological deficits on admission. The mean maximum thickness of the CSDH was 12 mm. Only one of these cases (4%) required surgical drainage 6 weeks after steroid therapy. One patient died of an unrelated stroke (mortality = 4%). Two patients (8%) were left severely disabled. No significant complication from steroid therapy was documented. Out of the 85 surgically treated patients, 69 patients underwent surgical drainage in addition to steroid therapy (Group 2). Thirteen patients were treated with burr-hole drainage only (Group 3). The mean maximum thickness of the CSDH for these two groups were both 16 mm. Comparing with group 1, the redrainage rate of Group 2 [4% (3/69, p = 1)] and that of Group 3 [15% (2/13, p = 0.253)] were not significantly different. 50% of patients in Group 4 (2/4, p = 0.039) required delayed surgical drainage. The mortality rates of Groups 2, 3 and 4 were 3% (2/69, p = 1), 15% (2/13, p = 0.253) and 50% (2/4, p = 0.039), respectively. Our results suggest that steroid treatment in a selected group of patients is a good option, particularly in patients with co-morbidity.

A randomized controlled trial of surgery vs steroid injection for carpal tunnel syndrome

BACKGROUND

Decompressive surgery and steroid injection are widely used forms of treatment for carpal tunnel syndrome (CTS) but there is no consensus on their effectiveness in comparison to each other. The authors evaluated the efficacy of surgery vs steroid injection in relieving symptoms in patients with CTS.

METHODS

The authors conducted a randomized, single blind, controlled trial. Fifty patients with electrophysiologically confirmed idiopathic CTS were randomized and assigned to open carpal tunnel release (25 patients) or to a single injection of steroid (25 patients). Patients were followed up at 6 and 20 weeks. The primary outcome was symptom relief in terms of the Global Symptom Score (GSS), which rates symptoms on a scale of 0 (no symptoms) to 50 (most severe). Nerve conduction studies and grip strength measurements were used as secondary outcome assessments.

RESULTS

At 20 weeks after randomization, patients who underwent surgery had greater symptomatic improvement than those who were injected. The mean improvement in GSS after 20 weeks was 24.2 (SD 11.0) in the surgery group vs 8.7 (SD 13.0) in the injection group (p < 0.001); surgical decompression also resulted in greater improvement in median nerve distal motor latencies and sensory nerve conduction velocity. Mean grip strength in the surgical group was reduced by 1.7 kg (SD 5.1) compared with a gain of 2.4 kg (SD 5.5) in the injection group.

CONCLUSION

Compared with steroid injection, open carpal tunnel release resulted in better symptomatic and neurophysiologic outcome but not grip strength in patients with idiopathic carpal tunnel syndrome over a 20-week period.

Third ventricular cavernous haemangioma

We report a case of a third ventricular cavernous haemangioma (cavernoma). Cavernomas rarely occur within the ventricular system. Only 47 well-documented cases have been reported in the literature, 21 of which were located in the third ventricle. Cavernomas should be considered in the differential diagnosis of third ventricular lesions. Ventriculoscopy is very useful in establishing the diagnosis.

Aneurysm recurrence after treatment of paraclinoid/ophthalmic segment aneurysms--a treatment-modality assessment

OBJECT

The treatment of 21 paraclinoid/ophthalmic segment internal carotid artery aneurysms (PCOSAs) over a seven year period in a regional neurosurgical center was reviewed to assess the degree of obliteration and recurrence rate of these aneurysms after treatment by surgical and endovascular methods.

METHOD AND RESULT

An assessment of the clinical notes, operation records and cerebral angiograms was made to evaluate the rate of residual and recurrent aneurysms after treatment and at follow-up. In the coiling group, the aneurysm recurrence rate was eight out of fifteen aneurysms (53%). Four recurrences were from previously totally occluded aneurysms. Out of the six surgical cases, five had follow-up angiography performed. All had stable occlusions of their aneurysms including one with subtotal occlusion. Two clipping procedures after previous coiling achieved total occlusion of aneurysm on follow-up angiography.

CONCLUSION

Based on our case series we conclude that PCOSAs frequently recur after primary treatment. GDC coiling was associated with a higher rate of recurrent aneurysms when compared with surgical treatment. A review of the literature on the surgical and endovascular treatment of PCOSAs support this observation.

Intravenous magnesium sulfate to improve outcome after aneurysmal subarachnoid hemorrhage: interim report from a pilot study

OBJECTIVES

Magnesium sulfate (MgSO4) may be useful in preventing neurological injury after subarachnoid haemorrhage (SAH). In this randomized, double-blind study we evaluated the safety and efficacy of MgSO4 infusion to improve clinical outcome after aneurysmal SAH.

METHODS

With ethics committee approval and informed consents, 45 patients with SAH were randomly allocated to receive either MgSO4 80 mmol/day or saline infusion for 14 days. All patients also received intravenous nimodipine. Episodes of vasospasm were treated with hypertensive, hypervolemic therapy. Neurological status was assessed 3 months after haemorrhage using Barthel index and Glasgow outcome scale (GOS). Incidences of cardiac and pulmonary complications were also recorded. Data were compared between groups using Mann-Whitney or Fisher exact tests as appropriate. P < 0.05 was considered significant.

RESULTS

Patient characteristics, severity of SAH and surgical treatment did not differ between groups. Although the number of episodes was not reduced, MgSO4 shortened the duration of vasospasm. Patients receiving MgSO4 tended to have fewer neurological deficits, better functional recovery and an improved score in GOS. However, none of these outcome variables reached statistical significance. The incidence of cardiac and pulmonary complications in the MgSO4 group (43%) was also similar to that in the saline group (59%), P = 0.14.

CONCLUSIONS

MgSO4 infusion after aneurysmal SAH is well tolerated and may be useful in producing better outcome. A larger study is required to confirm the neuroprotective effect of MgSO4.

Magnesium sulfate for brain protection during temporary cerebral artery occlusion

We evaluated the effects of magnesium sulfate on brain tissue oxygen (PtO2) tension, carbon dioxide (PtCO2) tension and pH (pHt) in patients undergoing temporary artery occlusion for clipping of cerebral aneurysm. We studied 18 patients with aneurysmal subarachnoid hemorrhage. All patients received standard anesthetics using target controlled infusion of propofol (3 microg/ml) and remifentanil (10 ng/ml). After craniotomy, a calibrated multiparameter sensor (Neurotrend, Diametrics Medical, Minneapolis, MN) was inserted to measure PtO2, PtCO2 and pHt in tissue at risk of ischemia during temporary artery occlusion. Patients were then randomly allocated to receive either intravenous saline or magnesium 20 mmol over 10 min followed by an infusion 4 mmol/h. Plasma magnesium concentration, brain tissue gases and pHt were determined at baseline, 30 min after study drug infusion and 4 min after temporary clipping. Data were analyzed by factorial ANOVA with repeated measures. Intergroup difference was compared with unpaired t test. P value < 0.05 was considered significant. Patient characteristics, baseline brain tissue gases and pHt did not differ between groups. Magnesium infusion increased PtO2 by 34%. Following temporary artery occlusion, PtO2 and pHt decreased and PtCO2 increased in both groups. However, tissue hypoxia was less severe and the rate of PtO2 decline was slower in the magnesium group. Our data suggested that magnesium enhances tissue oxygenation and attenuates hypoxia during temporary artery occlusion.

Effect of ischemic preconditioning on brain tissue gases and pH during temporary cerebral artery occlusion

Previous studies have demonstrated that a brief period of ischemia protect against subsequent severe ischemic insults to the brain, i.e. preconditioning. We evaluated the effects of ischemic preconditioning, produced by 2 min proximal temporary artery occlusion, on brain tissue gases and acidity during clipping of cerebral aneurysm. Twelve patients with aneurysmal subarachnoid hemorrhage were recruited. All patients received standard anesthetics. After craniotomy, a calibrated multiparameter catheter was inserted to measure oxygen (PtO2) tension, carbon dioxide (PtCO2) tension and pH (pHt) in tissue at risk of ischemia during temporary artery occlusion. In patients assigned to the preconditioning group, proximal artery was occluded initially for 2 min and was allowed to reperfuse for 30 min. All patients underwent cerebral artery occlusion for clipping of aneurysm. The rate of change in PtO2, PtCO2 and pHt after artery occlusion were compared between groups using unpaired t test. Baseline brain tissue gases and pHt were similar between groups. Following artery occlusion, the decline in PtO2 and pHt were significantly slower in the preconditioning group compared with the routine care group. These results suggested that ischemic preconditioning attenuates tissue hypoxia during subsequent artery occlusion. Brief occlusion of the proximal artery may be a simple maneuver for brain protection during complex cerebrovascular surgery.

A review of isolated third nerve palsy without subarachnoid hemorrhage using computed tomographic angiography as the first line of investigation

INTRODUCTION

Digital subtraction angiography is recognized as the standard investigation for isolated third nerve palsy thought to be caused by an expanding aneurysm. We reviewed our experience in using computed tomographic angiography (CTA) as the first line investigation for patients presenting with isolated third nerve palsy without subarachnoid hemorrhage.

METHOD

We retrieved the medical records of 34 patients who had presented with isolated third nerve palsy without associated subarachnoid hemorrhage to our institution between January 1998 and July 2001. The clinical history, course and outcome as well as the radiological data was reviewed.

RESULTS

A total of nine structural lesions (26%) were noted as the etiology of the third nerve palsy. All of the five posterior communicating artery aneurysms were picked up by the CTA. Neither the presence nor the absence of painful complete third nerve palsy was of diagnostic value for intracranial aneurysm.

CONCLUSION

A good quality CTA is sufficient to detect a compressive aneurysm and may detect other structural lesions. This allows neurosurgeons to plan the management of patients with isolated third nerve palsy. Patients in whom CTA results are inconclusive should be further investigated with catheter angiography.

Spinal shock in spontaneous cervical spinal epidural haematoma

A young man presented with quadriparesis and spinal shock because of a spontaneous cervical spinal epidural haematoma was reported. Immediate MRI diagnosis followed by emergency decompression with six hours of presentation resulted in complete recovery.

Intraventricular meningioma with drop metastases and subgaleal metastatic nodule

We report a case of malignant intraventricular meningioma with CSF drop metastases and an implantation metastatic subgaleal nodule in a 53-year-old woman. Malignant intraventricular meningiomas are rare with only seven cases being reported in the literature. These tumours can be very aggressive and one should consider immediate postoperative radiotherapy.

Endovascular GDC-mediated flow-reversal for complex posterior circulation saccular aneurysms. A report of two cases and critical appraisal

Two patients with giant complex saccular aneurysms of the proximal basilar artery were managed with flow-reversal using the endovascular route. Complete obliteration of the aneurysm was successful in one patient resulting in long term survival (8 year follow-up completed). Incomplete obliteration of the aneurysm persisted in the other patient, resulting in recurrence and a fatal haemorrhage one year after treatment. Endovascular flow-reversal is a good treatment option for these lesions with a high surgical risk. However, persistent incomplete thrombosis of these aneurysms following flow-reversal should lead to the consideration of alternate treatment strategies.

The surgical treatment of intracranial aneurysms based on computer tomographic angiography alone--streamlining the acute mananagement of symptomatic aneurysms

BACKGROUND

We aimed to prospectively assess the usefulness of computer tomographic angiography (CTA) in streamlining the management of symptomatic intracranial aneurysms in a tertiary neurosurgical unit, from admission to surgery.

METHODS

We performed a prospective evaluation over a 2-year period of all symptomatic intracranial aneurysms managed according to a standardized departmental protocol, to assess how CTA has impacted the decision-making process pertaining to the suitability of this investigation to proceed directly to surgery.

FINDINGS

A total of 90 patients with intracranial aneurysms were treated over the 2-year period. 23 (26%) underwent endovascular occlusion while 67 (74%) patients underwent a surgical clipping procedure. In the surgical group, 22 (33%) patients had their aneurysms clipped based on CTA alone, while 45 (67%) required additional conventional angiography prior to surgery. Thus around one quarter of all patients treated for symptomatic intracranial aneurysms in our unit had their aneurysm secured surgically based solely on CTA.

INTERPRETATION

CTA significantly influences the acute management of symptomatic intracranial aneurysms by streamlining the decision-making process during the early and acute management of these lesions.

Inferior vena caval filters following deep vein thrombosis in patients with ruptured intracranial aneurysm

Anticoagulant therapy is highly effective and prevents death in more than 95% of patients who have suffered pulmonary embolism following deep vein thrombosis. Inferior vena caval filters provide an alternative to full anticoagulation in those patients at highest risk of catastrophic haemorrhagic complications. We report on two patients who developed deep vein thrombosis following ruptured unsecured intracranial aneurysms. Inferior vena caval filters were inserted prior to aneurysm clipping, as a prophylactic measure to prevent pulmonary embolism while awaiting surgery. The patients did not receive anticoagulant therapy following successful clipping of the aneurysm. Both patients had clinical resolution of the lower limb swelling and no radiological evidence of propagation of the thrombus. During 18 months of follow-up there were no complications and no evidence of post-thrombotic syndrome.

Lytic skull metastasis secondary to thyroid carcinoma in an adolescent

We report an unusual case of skull metastasis secondary to thyroid carcinoma in an adolescent girl. The 18-year-old presented with an occipital scalp swelling of 5 years' duration. She reported having thyroid surgery in mainland China 10 years previously. Radiological investigations on presentation demonstrated a lytic hypervascular skull lesion. Preoperative angiography and embolisation was followed by surgical excision. Pathological examination showed the lesion to be a thyroid carcinoma with a predominantly follicular pattern and a completion hemithyroidectomy was subsequently performed. Computed tomography of the thorax showed small micronodules in both lung fields compatible with metastases. The patient was given whole body iodine-131 internal radiation treatment and subsequently commenced thyroid-stimulating hormone-suppressive treatment with thyroxine. The management of thyroid carcinoma and subsequent skull metastasis in children and adolescents is reviewed and controversial points are highlighted.

Vertebrobasilar artery dissections: current practice

Nine patients with vertebrobasilar artery dissections who presented with neurological symptoms or subarachnoid haemorrhage were identified and treated in the Neurosurgical Unit at the Prince of Wales Hospital in Hong Kong. An account of these patients is given and their treatment described. This paper further reviews selected literature to outline the concepts and appropriate management of vertebrobasilar artery dissections.

Childhood posterior fossa pial-dural arteriovenous fistula treated by endovascular occlusion

Posterior fossa dural arteriovenous fistulae in children are rare lesions that are difficult to treat effectively. We report a case of a 2-year-old girl with such a fistula, who presented clinically with progressive neurological deficit. The lesion was treated by endovascular occlusion, resulting in radiological and clinical cure.

The management of residual and recurrent intracranial aneurysms after previous endovascular or surgical treatment--a report of eighteen cases

OBJECT

We wish to report our experience in the management of residual or recurrent intracranial aneurysm after previous endovascular or surgical treatment.

METHODS

We performed a retrospective review of the clinical notes, operation records and cerebral angiograms of eighteen patients who were known to have undergone treatment for residual or recurrent aneurysms.

RESULTS

During the period of April 1994 to May 1999, 210 patients were treated for an intracranial aneurysm either surgically or by endovascular methods. Eighteen of these patients (8.6%) were subsequently treated for residual or recurrent aneurysm. Thirteen achieved a complete occlusion. Complete occlusion was achieved in five of the eight patients who underwent endovascular treatment as a second procedure. Seven out of ten surgical cases achieved complete occlusion. Fifteen patients made a good recovery according to the Glasgow Outcome Score. Two patients who presented in a poor grade subarachnoid haemorrhage (SAH) were left severely disabled. One patient died after retreatment.

CONCLUSIONS

The treatment of cerebral aneurysm remnants can be performed effectively using a variety of modalities. The original purpose of the treatment, which is total occlusion of the lesion, can thus be achieved.

Spinal cord pilocytic astrocytoma with cranial meningeal metastases

Dissemination of tumour cells along the cerebrospinal fluid (CSF) pathway has been reported mostly in medulloblastomas, germ cell tumours or high grade gliomas. Juvenile pilocytic astrocytoma (JPA) is usually a benign astrocytoma. However, drop metastases of indolent nature from intracranial tumours to the spinal cord are documented. All of the previously reported cases represent metastases of cerebellar or hypothalamic tumours spreading to the spinal cord. We document in this paper the first report of a spinal cord pilocytic astrocytoma spreading via the CSF to the cerebral meninges. A 9 year old girl had a JPA of C5 to C7 subtotally resected. Two and a half years later she presented with hydrocephalus with radiologically meningeal enhancement. The meninges were biopsied which showed metastatic JPA. The girl was relatively well 4 years after initial surgery with residual tumour. Spinal cord JPA can rarely metastasize to the cranial meninges. Similar to intracranial tumours which spread to the spinal cord, such metastatic lesions are indolent.

Magnesium sulfate in the management of patients with Fisher Grade 3 subarachnoid hemorrhage: a pilot study

OBJECTIVE

To evaluate the effect of magnesium sulfate (MgSO4) on the clinical course of patients with severe aneurysmal subarachnoid hemorrhage (SAH).

METHODS

Ten patients with Fisher Grade 3 aneurysmal SAH were evaluated. The patients were given a bolus as well as a constant infusion of intravenous MgSO4 up to 10 days postictus. Blood magnesium levels were obtained to adjust the daily requirement of MgSO4. The goal was to raise the serum level to 2.0 to 2.5 mmol/L or twice the baseline serum level. Daily transcranial Doppler (TCD) ultrasonography was performed on each patient, insonating both anterior cerebral and middle cerebral arteries. Further management followed standard protocols, including the use of nimodipine and hypervolemic therapy. TCD ultrasonographic findings, as well as clinical evidence of cerebral vasospasm, were documented. All patients had a 3-month assessment using the Glasgow Outcome Scale.

RESULTS

After administration of a 20 mmol MgSO4 bolus infusion and an average daily continuous infusion of 84.7 mmol, 8 of 10 patients achieved the predetermined serum magnesium levels. No adverse affects were noted during the infusions. Five patients exhibited evidence of vasospasm on TCD ultrasonography; vasospasm was severe in two patients (velocities, >200 cm/s). Three patients, including the two patients in whom TCD ultrasonography demonstrated severe vasospasm, exhibited clinical evidence of vasospasm. Two patients had a Glasgow Outcome Scale score of 3; the remainder had Glasgow Outcome Scale scores of 5.

CONCLUSION

Administration guidelines for the use of MgSO4 in aneurysmal SAH were established. A prospective double-blind placebo-controlled trial is required to establish the effectiveness of MgSO4 for treating vasospasm in aneurysmal SAH.

Intraoperative digital subtraction angiography in neurovascular disorders

Intraoperative digital subtraction angiography is useful for assessing the results of complex neurovascular procedures. Fifty-five patients with AVMs, aneurysms (Berry and bacterial), carotid-cavernous fistulae, spontaneous intracranial haemorrhages and penetrating head injuries had intraoperative angiograms. Sixteen of these patients had findings on the angiogram which altered the surgical procedure. There were no angiographic complications. We found intraoperative digital subtraction angiography a valuable adjunct to several neurovascular procedures.