- Email: [email protected]
Intraventricular brain abscess
1314
Case Reports / Journal of Clinical Neuroscience 19 (2012) 1314–1316
Intraventricular brain abscess Nisha Gadgil, Roukoz B. Chamoun, Shankar P. Gopinath ⇑ Department of Neurosurgery, Baylor College of Medicine, 1709 Dryden, Suite 750, Houston, TX 77030, USA
a r t i c l e
i n f o
Article history: Received 10 October 2011 Accepted 12 October 2011
Keywords: Brain abscess Intracranial infection Intraventricular abscess
a b s t r a c t Unlike an intraventricular rupture of a brain abscess, a primary intraventricular abscess is rare. While the former usually presents with acute clinical deterioration and carries a high rate of mortality, the latter tends to present in a subacute fashion. In this paper, we present a 62-year-old female with an intraventricular brain abscess. We discuss the pathogenesis of this clinical entity, describe the management options and review the literature on this topic. Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction The presence of purulent material in the ventricular system usually results from intraventricular rupture of an intraparenchymal brain abscess, which is not rare.2 Such a rupture has a mortality rate of up to 80%, and presents with acute deterioration in the clinical condition of the patient.2 The term ‘‘intraventricular abscess’’ refers to a different clinical entity in which the intraventricular pus is contained within a surrounding capsule, and where the patient’s clinical presentation is subacute. A literature search yielded only five previously reported cases of intraventricular abscess.1,3,5–7 In this paper, we report a primary intraventricular brain abscess located within the lateral ventricle and review the published literature on this topic. 2. Case report A 62-year-old previously healthy female presented with a oneweek history of headache, nausea and vomiting that progressed to altered mental status. Her medical history was significant for a history of injecting her gums with saline as part of a dental procedure. On admission, she was alert but confused and unintelligible. She was following simple commands and had no focal neurologic deficit. She was found to have fever and leukocytosis, and empiric antibiotic therapy was initiated. MRI of the brain showed an intraventricular cystic lesion with a ring enhancement (Figs. 1 and 2) and restricted diffusion (Fig. 3) suggestive of an intraventricular abscess. A right frontal craniotomy with transcortical approach to the right lateral ventricle was performed. The ventricle was found to contain a large encapsulated collection of pus. The abscess was evacuated and the ventricle thoroughly irrigated. A ventriculostomy catheter was left at the end of the procedure due to the risk of hydrocephalus. The patient was started on a regimen of ceftriaxone, vancomycin, and metronidazole. Cultures grew coagulase negative Staphylococcus and Streptococcus mitis. At postoperative day 9, it was decided to give a one-week course of intraventricular vancomycin 10 mg daily through the ventriculostomy catheter. Intravenous (IV) antibiotics were continued for a total of five weeks, followed by four weeks of oral antibiotics. The ventriculostomy catheter was removed after three weeks. The patient made a
⇑ Corresponding author. Tel.: +1 713 873 2794; fax: +1 713 798 8063. E-mail address: [email protected] (S.P. Gopinath).
good recovery with no neurological deficits and no recurrence of disease up to eight months of follow-up.
3. Discussion 3.1. Pathogenesis of intraventricular abscess In contrast to intraventricular rupture of abscess, a primary intraventricular abscess is a slowly progressing infectious process evolving from an area of cerebritis or ventriculitis. Unless iatrogenic, introduction of pathogens to the ventricular system is either hematogenous or through the cerebrospinal fluid (CSF). One theory proposes that bacteria enter the ventricles through the choroid plexus, an area of relative laxity in the blood–brain barrier.3 Once in the ventricles, inflammation may bring about adhesions and obstruction of the ventricular system. Infection is then confined to a single ventricle and leads to local abscess
Fig. 1. Axial T1-weighted brain MRI with contrast showing a ring-enhancing intraventricular lesion involving the right lateral ventricle. Note that the wall of the left lateral ventricle is not enhancing.
1315
Case Reports / Journal of Clinical Neuroscience 19 (2012) 1314–1316
Fig. 2. Coronal T1-weighted brain MRI with contrast showing the ring-enhancing intraventricular lesion. Note that the right temporal horn is trapped and dilated, but its wall is not enhancing.
Fig. 3. Axial diffusion sequence brain MRI showing that the intraventricular lesion has diffusion restriction.
3.3. Treatment considerations formation. It has been proposed that a subclinical anatomical abnormality may facilitate the entrapment of infection within a ventricle.1
3.2. Review of literature To our knowledge there are only five previous reports of intraventricular brain abscess (Table 1).1,3,5–7 Presenting symptoms were similar to any other brain abscess. CT scans or MRI in all patients reviewed demonstrated a ring-enhancing lesion within the ventricular system. Perilesional edema was typical, and in some cases the lesion obstructed CSF circulation, resulting in hydrocephalus. Open surgery for abscess drainage was utilized in three of the five patients; stereotactic aspiration was used in two. A ventriculoperitoneal shunt was used in two. Resolution of the abscess was noted in all patients.
There are two options for the treatment of intraventricular brain abscess: open surgery through craniotomy, or stereotactic aspiration. Surgical intervention is a very reasonable early step, allowing confirmation of the diagnosis, collection of a specimen, and evacuation of the collection. In our case, we felt that open surgery would allow adequate evacuation of the abscess and irrigation of the ventricles. The role of intraventricular (IVT) antibiotics in the treatment of intraventricular abscess has not previously been explored. IVT antibiotics in addition to IV antibiotics have been applied to patients with abscess rupture and severe meningitis producing improved clinical course.4 IV vancomycin at 2000 mg/day typically does not reach therapeutic levels of at least 5 lg/mL in the CSF due to impaired passage across the blood–brain barrier.4 Increasing IV antibiotic dosage to achieve adequate CSF concentrations may lead to systemic toxicity. However, IVT vancomycin does not lead to toxicity at this level.4 Intrathecal antibiotic injection
Table 1 Reports of intraventricular abscess Patient no.
Yearref
Age (years)/ sex
Predisposing factors
Location of abscess
Isolate
Treatment
Shunt
Antibiotics
Outcome
1
19936
40/M
–
Left LV
Vancomycin, Rifampin
Resolution
19997
26/F
–
Right LV
VP
Antitubercular
Resolution
3
19983
56/M
–
Left LV
Nocardia asteroides
Stereotactic aspiration Craniotomy with total excision Craniotomy with total excision
–
2
Staphylococcus aureus Acid fast bacilli
–
Trimethoprim/ sulfamethoxazole, Ceftriaxone, Amikacin
4
20031
13/M
Cystic dilation of left LV
Left LV
Cefotaximum
20075
23/M
Chronic suppurative otitis media; right transverse sinus thrombosis
Fourth Ventricle
Stereotactic aspiration 2 Craniectomy with total excision
–
5
Streptococcus pneumoniae Klebsiella oxytoca
VP
Unknown
Resolution with persistent homonymous hemianopsia Relapse, then resolution Resolution
LV = lateral ventricle, VP = ventriculoperitoneal.
1316
Case Reports / Journal of Clinical Neuroscience 19 (2012) 1316–1320
may not bring about sufficient ventricular concentrations to be effective. Therefore, we believe that strong consideration should be given to IVT antibiotics in cases of intraventricular brain abscess. References 1. Lambo A, Nchimi A, Khamis J, et al. Primary intraventricular brain abscess. Neuroradiology 2003;45:908–10. 2. Lee TH, Chang WN, Su TM, et al. Clinical features and predictive factors of intraventricular rupture in patients who have bacterial brain abscesses. J Neurol Neurosurg Psychiatry 2007;78:303–9.
3. Mogilner A, Jallo G, Zagzag D, et al. Nocardia abscess of the choroid plexus: clinical and pathological case report. Neurosurgery 1998;43:949–52. 4. Pfausler B, Spiss H, Beer R, et al. Treatment of staphylococcal ventriculitis associated with external cerebrospinal fluid drains: a prospective randomized trial of intravenous compared with intraventricular vancomycin therapy. J Neurosurg 2003;98:1040–4. 5. Pruthi N, Devi BI, Shivshankar JJ, et al. Abscess – a rare fourth ventricular mass. Acta Neurochir 2007;149:1179–81. 6. Robinson EN. Staphylococcal meningitis can present as an abscess of a single lateral ventricle. Clin Infect Dis 1993;16:435–8. 7. Vajramani GV, Devi BI, Hegde T, et al. Intraventricular tuberculous abscess: a case report. Neurol India 1999;47:327–9.
doi:http://dx.doi.org/10.1016/j.jocn.2011.10.016
Perioperative management of a neurosurgical patient requiring antiplatelet therapy Khoi D. Than a,⇑, Pratik Rohatgi b, Thomas J. Wilson a, B. Gregory Thompson a a b
Department of Neurosurgery, University of Michigan, 1500 E. Medical Center Drive, Room 3552 TC, Ann Arbor, Michigan 48109-5338, USA Department of Neurosurgery, Pennsylvania State University, Hershey, Pennsylvania, USA
a r t i c l e
i n f o
Article history: Received 11 November 2011 Accepted 28 December 2011
Keywords: Antiplatelet therapy Aspirin Clopidogrel Eptifibatide Ibuprofen Neurovascular stent Ventriculoperitoneal shunt
a b s t r a c t In patients who undergo neurovascular stent placement with postoperative dual antiplatelet therapy to prevent in-stent thrombosis, there is no protocol for balancing the risk of acute stent thrombosis and bleeding if urgent neurosurgical procedures are required. We detail perioperative management of dual antiplatelet therapy in a 66-year-old man with a dolichoectatic aneurysm of the basilar artery treated with a Pipeline stent. Postoperatively, the patient was placed on aspirin and clopidogrel to prevent instent thrombosis. One month after the procedure, his neurological status declined secondary to obstructive hydrocephalus. His condition necessitated urgent placement of a ventriculoperitoneal shunt, despite the dual antiplatelet therapy for the flow-diverting Pipeline stent. Aspirin and clopidogrel were discontinued seven days prior to the planned shunt placement. To minimize time off antiplatelet therapy, aspirin was immediately replaced with ibuprofen. Eptifibatide was then started three days prior to surgery. The ibuprofen/eptifibatide bridge was discontinued at midnight prior to surgery. Aspirin was restarted on the first postoperative day and clopidogrel was restarted on the second postoperative day. The patient tolerated shunt placement without excessive bleeding or hemorrhagic complications. During the remainder of his hospital course, no evidence of stent thrombosis or intracranial hemorrhage was noted. We conclude that management of antiplatelet prophylaxis for neurovascular stent thrombosis in patients requiring urgent neurosurgical procedures may be successfully achieved by bridging aspirin and clopidogrel with ibuprofen and eptifibatide in the preoperative period. Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction Endovascular neurosurgery procedures are used to manage a growing number of pathologies, ranging from aneurysms to cerebral ischemic diseases to arteriovenous malformations.1–3 Many patients who undergo endovascular procedures are treated with neurovascular stents, requiring postoperative dual antiplatelet therapy with aspirin and clopidogrel to prevent in-stent thrombosis. If these patients require additional neurosurgical procedures, neurosurgeons are faced with the clinical challenge of balancing the risk of acute stent thrombosis with the risk of operative and postoperative bleeding. There are no standards on how to manage patients who undergo endovascular procedures with neurovascular stents who then require postoperative dual antiplatelet therapy with aspirin and clopidogrel to prevent in-stent thrombosis. The literature provides little guidance, as neurosurgical reports are sparse and the work
⇑ Corresponding author. Tel.: +1 734 936 5732; fax: +1 734 936 9294. E-mail address: [email protected] (K.D. Than).
from cardiovascular stenting provides few evidence-based recommendations regarding neurosurgical patients. In this review, we provide an illustrative case detailing the antiplatelet management of a patient who had a ventriculoperitoneal shunt (VPS) placed one month after receiving a Pipeline flow-diverting stent (ev3, Irvine, CA, USA) in the basilar artery, utilizing a preoperative ibuprofen and eptifibatide bridge in place of aspirin and clopidogrel. The patient was managed successfully using this protocol. The aim of this report is to provide one option for minimizing time off antiplatelet therapy in patients with a recently placed intracranial stent. 2. Case report A 66-year-old man presented with a six-month history of progressive dysarthria, urinary incontinence, episodes of choking and aspiration, ataxia, lack of coordination, disequilibrium, and headaches. Six months prior to these symptoms, the patient was in good health and worked as a police officer. Neurological examination demonstrated dysarthria, a wide-based ataxic gait, and right-sided appendicular dysmetria with bilateral tremor. A CT angiogram (CTA) and MRI demonstrated a 2.8 cm 3.1 cm 3.8 cm fusiform dolichoectatic aneurysm of the
Case Reports / Journal of Clinical Neuroscience 19 (2012) 1314–1316
Intraventricular brain abscess Nisha Gadgil, Roukoz B. Chamoun, Shankar P. Gopinath ⇑ Department of Neurosurgery, Baylor College of Medicine, 1709 Dryden, Suite 750, Houston, TX 77030, USA
a r t i c l e
i n f o
Article history: Received 10 October 2011 Accepted 12 October 2011
Keywords: Brain abscess Intracranial infection Intraventricular abscess
a b s t r a c t Unlike an intraventricular rupture of a brain abscess, a primary intraventricular abscess is rare. While the former usually presents with acute clinical deterioration and carries a high rate of mortality, the latter tends to present in a subacute fashion. In this paper, we present a 62-year-old female with an intraventricular brain abscess. We discuss the pathogenesis of this clinical entity, describe the management options and review the literature on this topic. Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction The presence of purulent material in the ventricular system usually results from intraventricular rupture of an intraparenchymal brain abscess, which is not rare.2 Such a rupture has a mortality rate of up to 80%, and presents with acute deterioration in the clinical condition of the patient.2 The term ‘‘intraventricular abscess’’ refers to a different clinical entity in which the intraventricular pus is contained within a surrounding capsule, and where the patient’s clinical presentation is subacute. A literature search yielded only five previously reported cases of intraventricular abscess.1,3,5–7 In this paper, we report a primary intraventricular brain abscess located within the lateral ventricle and review the published literature on this topic. 2. Case report A 62-year-old previously healthy female presented with a oneweek history of headache, nausea and vomiting that progressed to altered mental status. Her medical history was significant for a history of injecting her gums with saline as part of a dental procedure. On admission, she was alert but confused and unintelligible. She was following simple commands and had no focal neurologic deficit. She was found to have fever and leukocytosis, and empiric antibiotic therapy was initiated. MRI of the brain showed an intraventricular cystic lesion with a ring enhancement (Figs. 1 and 2) and restricted diffusion (Fig. 3) suggestive of an intraventricular abscess. A right frontal craniotomy with transcortical approach to the right lateral ventricle was performed. The ventricle was found to contain a large encapsulated collection of pus. The abscess was evacuated and the ventricle thoroughly irrigated. A ventriculostomy catheter was left at the end of the procedure due to the risk of hydrocephalus. The patient was started on a regimen of ceftriaxone, vancomycin, and metronidazole. Cultures grew coagulase negative Staphylococcus and Streptococcus mitis. At postoperative day 9, it was decided to give a one-week course of intraventricular vancomycin 10 mg daily through the ventriculostomy catheter. Intravenous (IV) antibiotics were continued for a total of five weeks, followed by four weeks of oral antibiotics. The ventriculostomy catheter was removed after three weeks. The patient made a
⇑ Corresponding author. Tel.: +1 713 873 2794; fax: +1 713 798 8063. E-mail address: [email protected] (S.P. Gopinath).
good recovery with no neurological deficits and no recurrence of disease up to eight months of follow-up.
3. Discussion 3.1. Pathogenesis of intraventricular abscess In contrast to intraventricular rupture of abscess, a primary intraventricular abscess is a slowly progressing infectious process evolving from an area of cerebritis or ventriculitis. Unless iatrogenic, introduction of pathogens to the ventricular system is either hematogenous or through the cerebrospinal fluid (CSF). One theory proposes that bacteria enter the ventricles through the choroid plexus, an area of relative laxity in the blood–brain barrier.3 Once in the ventricles, inflammation may bring about adhesions and obstruction of the ventricular system. Infection is then confined to a single ventricle and leads to local abscess
Fig. 1. Axial T1-weighted brain MRI with contrast showing a ring-enhancing intraventricular lesion involving the right lateral ventricle. Note that the wall of the left lateral ventricle is not enhancing.
1315
Case Reports / Journal of Clinical Neuroscience 19 (2012) 1314–1316
Fig. 2. Coronal T1-weighted brain MRI with contrast showing the ring-enhancing intraventricular lesion. Note that the right temporal horn is trapped and dilated, but its wall is not enhancing.
Fig. 3. Axial diffusion sequence brain MRI showing that the intraventricular lesion has diffusion restriction.
3.3. Treatment considerations formation. It has been proposed that a subclinical anatomical abnormality may facilitate the entrapment of infection within a ventricle.1
3.2. Review of literature To our knowledge there are only five previous reports of intraventricular brain abscess (Table 1).1,3,5–7 Presenting symptoms were similar to any other brain abscess. CT scans or MRI in all patients reviewed demonstrated a ring-enhancing lesion within the ventricular system. Perilesional edema was typical, and in some cases the lesion obstructed CSF circulation, resulting in hydrocephalus. Open surgery for abscess drainage was utilized in three of the five patients; stereotactic aspiration was used in two. A ventriculoperitoneal shunt was used in two. Resolution of the abscess was noted in all patients.
There are two options for the treatment of intraventricular brain abscess: open surgery through craniotomy, or stereotactic aspiration. Surgical intervention is a very reasonable early step, allowing confirmation of the diagnosis, collection of a specimen, and evacuation of the collection. In our case, we felt that open surgery would allow adequate evacuation of the abscess and irrigation of the ventricles. The role of intraventricular (IVT) antibiotics in the treatment of intraventricular abscess has not previously been explored. IVT antibiotics in addition to IV antibiotics have been applied to patients with abscess rupture and severe meningitis producing improved clinical course.4 IV vancomycin at 2000 mg/day typically does not reach therapeutic levels of at least 5 lg/mL in the CSF due to impaired passage across the blood–brain barrier.4 Increasing IV antibiotic dosage to achieve adequate CSF concentrations may lead to systemic toxicity. However, IVT vancomycin does not lead to toxicity at this level.4 Intrathecal antibiotic injection
Table 1 Reports of intraventricular abscess Patient no.
Yearref
Age (years)/ sex
Predisposing factors
Location of abscess
Isolate
Treatment
Shunt
Antibiotics
Outcome
1
19936
40/M
–
Left LV
Vancomycin, Rifampin
Resolution
19997
26/F
–
Right LV
VP
Antitubercular
Resolution
3
19983
56/M
–
Left LV
Nocardia asteroides
Stereotactic aspiration Craniotomy with total excision Craniotomy with total excision
–
2
Staphylococcus aureus Acid fast bacilli
–
Trimethoprim/ sulfamethoxazole, Ceftriaxone, Amikacin
4
20031
13/M
Cystic dilation of left LV
Left LV
Cefotaximum
20075
23/M
Chronic suppurative otitis media; right transverse sinus thrombosis
Fourth Ventricle
Stereotactic aspiration 2 Craniectomy with total excision
–
5
Streptococcus pneumoniae Klebsiella oxytoca
VP
Unknown
Resolution with persistent homonymous hemianopsia Relapse, then resolution Resolution
LV = lateral ventricle, VP = ventriculoperitoneal.
1316
Case Reports / Journal of Clinical Neuroscience 19 (2012) 1316–1320
may not bring about sufficient ventricular concentrations to be effective. Therefore, we believe that strong consideration should be given to IVT antibiotics in cases of intraventricular brain abscess. References 1. Lambo A, Nchimi A, Khamis J, et al. Primary intraventricular brain abscess. Neuroradiology 2003;45:908–10. 2. Lee TH, Chang WN, Su TM, et al. Clinical features and predictive factors of intraventricular rupture in patients who have bacterial brain abscesses. J Neurol Neurosurg Psychiatry 2007;78:303–9.
3. Mogilner A, Jallo G, Zagzag D, et al. Nocardia abscess of the choroid plexus: clinical and pathological case report. Neurosurgery 1998;43:949–52. 4. Pfausler B, Spiss H, Beer R, et al. Treatment of staphylococcal ventriculitis associated with external cerebrospinal fluid drains: a prospective randomized trial of intravenous compared with intraventricular vancomycin therapy. J Neurosurg 2003;98:1040–4. 5. Pruthi N, Devi BI, Shivshankar JJ, et al. Abscess – a rare fourth ventricular mass. Acta Neurochir 2007;149:1179–81. 6. Robinson EN. Staphylococcal meningitis can present as an abscess of a single lateral ventricle. Clin Infect Dis 1993;16:435–8. 7. Vajramani GV, Devi BI, Hegde T, et al. Intraventricular tuberculous abscess: a case report. Neurol India 1999;47:327–9.
doi:http://dx.doi.org/10.1016/j.jocn.2011.10.016
Perioperative management of a neurosurgical patient requiring antiplatelet therapy Khoi D. Than a,⇑, Pratik Rohatgi b, Thomas J. Wilson a, B. Gregory Thompson a a b
Department of Neurosurgery, University of Michigan, 1500 E. Medical Center Drive, Room 3552 TC, Ann Arbor, Michigan 48109-5338, USA Department of Neurosurgery, Pennsylvania State University, Hershey, Pennsylvania, USA
a r t i c l e
i n f o
Article history: Received 11 November 2011 Accepted 28 December 2011
Keywords: Antiplatelet therapy Aspirin Clopidogrel Eptifibatide Ibuprofen Neurovascular stent Ventriculoperitoneal shunt
a b s t r a c t In patients who undergo neurovascular stent placement with postoperative dual antiplatelet therapy to prevent in-stent thrombosis, there is no protocol for balancing the risk of acute stent thrombosis and bleeding if urgent neurosurgical procedures are required. We detail perioperative management of dual antiplatelet therapy in a 66-year-old man with a dolichoectatic aneurysm of the basilar artery treated with a Pipeline stent. Postoperatively, the patient was placed on aspirin and clopidogrel to prevent instent thrombosis. One month after the procedure, his neurological status declined secondary to obstructive hydrocephalus. His condition necessitated urgent placement of a ventriculoperitoneal shunt, despite the dual antiplatelet therapy for the flow-diverting Pipeline stent. Aspirin and clopidogrel were discontinued seven days prior to the planned shunt placement. To minimize time off antiplatelet therapy, aspirin was immediately replaced with ibuprofen. Eptifibatide was then started three days prior to surgery. The ibuprofen/eptifibatide bridge was discontinued at midnight prior to surgery. Aspirin was restarted on the first postoperative day and clopidogrel was restarted on the second postoperative day. The patient tolerated shunt placement without excessive bleeding or hemorrhagic complications. During the remainder of his hospital course, no evidence of stent thrombosis or intracranial hemorrhage was noted. We conclude that management of antiplatelet prophylaxis for neurovascular stent thrombosis in patients requiring urgent neurosurgical procedures may be successfully achieved by bridging aspirin and clopidogrel with ibuprofen and eptifibatide in the preoperative period. Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction Endovascular neurosurgery procedures are used to manage a growing number of pathologies, ranging from aneurysms to cerebral ischemic diseases to arteriovenous malformations.1–3 Many patients who undergo endovascular procedures are treated with neurovascular stents, requiring postoperative dual antiplatelet therapy with aspirin and clopidogrel to prevent in-stent thrombosis. If these patients require additional neurosurgical procedures, neurosurgeons are faced with the clinical challenge of balancing the risk of acute stent thrombosis with the risk of operative and postoperative bleeding. There are no standards on how to manage patients who undergo endovascular procedures with neurovascular stents who then require postoperative dual antiplatelet therapy with aspirin and clopidogrel to prevent in-stent thrombosis. The literature provides little guidance, as neurosurgical reports are sparse and the work
⇑ Corresponding author. Tel.: +1 734 936 5732; fax: +1 734 936 9294. E-mail address: [email protected] (K.D. Than).
from cardiovascular stenting provides few evidence-based recommendations regarding neurosurgical patients. In this review, we provide an illustrative case detailing the antiplatelet management of a patient who had a ventriculoperitoneal shunt (VPS) placed one month after receiving a Pipeline flow-diverting stent (ev3, Irvine, CA, USA) in the basilar artery, utilizing a preoperative ibuprofen and eptifibatide bridge in place of aspirin and clopidogrel. The patient was managed successfully using this protocol. The aim of this report is to provide one option for minimizing time off antiplatelet therapy in patients with a recently placed intracranial stent. 2. Case report A 66-year-old man presented with a six-month history of progressive dysarthria, urinary incontinence, episodes of choking and aspiration, ataxia, lack of coordination, disequilibrium, and headaches. Six months prior to these symptoms, the patient was in good health and worked as a police officer. Neurological examination demonstrated dysarthria, a wide-based ataxic gait, and right-sided appendicular dysmetria with bilateral tremor. A CT angiogram (CTA) and MRI demonstrated a 2.8 cm 3.1 cm 3.8 cm fusiform dolichoectatic aneurysm of the