287

Ruptured Intracranial Mycotic Aneurysm: A Rare Cause of
Intracranial Hemorrhage
Keng-He Kong, MD, Kay-Fei Chan, MD
ABSTRACT. Kong K-H, Chan K-F. Ruptured intracranial mycotic aneurysm: a rare cause of intracranial
hemorrhage. Arch Phys Med Rehabil 1995;76:28%9.
• Intracranial mycotic aneurysm is a rare complication in patients with infective endocarditis occurring in about
2% to 10% of cases. Although the risk of rupture is about 1.7%, it is usually a catastrophic event with a fatality
rate of 80 %. Neurological deficits secondary to cortical involvement are common, given the frequency of intralobar
hemorrhage. We report two cases of intracerebral hemorrhage caused by ruptured intracranial mycotic aneurysms. Both had involvement of the right frontoparietal lobes with resultant left hemiparesis, left homonymous
hemianopia, and impairments of cognition and perceptual function. Despite intensive rehabilitation, their functional outcomes were less than satisfactory as they needed assistance in self-care activities and mobility on
discharge.
© 1995 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and
Rehabilitation
The incidence of neurological i n v o l v e m e n t in infective
endocarditis ranges from 30% 1 to 40%. 2 Despite the imp r o v e m e n t in prognosis of patients with infective endocarditis with antibiotic treatment, this incidence has remained
remarkably the same. 3 Clinical manifestations include seizure, delirium, stroke, meningoencephalitis, and even peripheral neuropathy. Intracranial infective a n e u r y s m is an
u n c o m m o n complication occuring in about 2% to 10% of
patients with infective endocarditis. 4-6 The true incidence is
probably m u c h higher because m a n y infective aneurysms
r e m a i n asymptomatic and some resolve with antibiotic treatment. Most of them remain asymptomatic with only about
1.7% rupturing with subsequent intracranial h e m o r r h a g e ]
W e report two cases of intracerebral hemorrhage caused by
ruptured intracranial mycotic aneurysms as a result of bacterial endocarditis, their neurological deficits and functional
outcomes after rehabilitation.
CASE 1
This 25-year-old female clerk with mitral valve prolapse complicated by mitral regurgitation was admitted to a neurosurgical facility for sudden onset of drowsiness and left hemiparesis. Clinical
examination showed impaired conscious level, conjugate deviation
of both eyes to ~the left and a left hemiparesis with associated
hyperreflexia. A grade 3/6 pansystolic murmur of mitral regurgitation was heard over the cardiac apex and there were splinter hemorrhages over the left index and middle fingers. She was afebrile and
no other stigmata of bacterial endocarditis was noted. There was
a history of dental extraction 4 weeks before admission. A diagnosis of bacterial endocarditis with intracranial hemorrhage was
made.
From the Departmentof RehabilitationMedicine,Tan Tock SengHospital,Singapore.
Submittedfor publicationJune 8, 1994. Acceptedin revisedform September28,
1994.
No commercialparty havinga directfinancialinterestin the resultsof the research
supporting this article has or will confer a benefit upon the authors or upon any
organizationwith whichthe authorsare associated.
Reprint requests to Kay-FeiChan, MD, Registrar, Departmentof Rehabilitation
•Medicine,Tan TockSengHospital,C/O Ang Mo Kio CommunityHospital, 17, Ang
Mo Kio Avenue9, Singapore2056.
© 1995 by the AmericanCongress of RehabilitationMedicineand the American
Academyof PhysicalMedicineand Rehabilitation

0003-9993/95/7603-309553.00/0

Fig 1--Four-vessel angiogram showing mycotic aneurysm
(arrow) at the junction of the right middle cerebral and anterior cerebral arteries.
Computed tomography (CT) scan of the brain showed a large
right frontoparietal hematoma with midline shift to the left. Fourvessel angiogram showed a mycotic aneurysm at the junction of
the right middle cerebral and anterior cerebral arteries (fig 1). Evacuation of the intracranial clot with excision of the ruptured mycotic
aneurysm was performed the following day. Laboratory studies
showed mild anemia, leucocytosis, and microscopic hematuria.
Histology of the aneurysm showed severe inflammation of the
vessel wall with neutrophilic and lymphocytic infiltrates, features

Arch Phys Med Rehabil Vol 76, March 1995

288

INTRACRANIAL MYCOTIC ANEURYSM, Kong
The patient was transferred to rehabilitation 6 weeks after admission. Clinically, she had signs of a major right hemispheric syndrome. There was a left hemiplegia, left homonymous hemianopia,
and neglect. Perseveration and impairment of praxis and memory
were also noted. Functionally, she was dependent in most selfcare activities and mobility and was also incontinent of bowel and
bladder. A graded rehabilitation program with emphasis on cueing
and compensatory measures was started. Despite this, only modest
functional gains were achieved. On discharge 8 weeks after rehabilitation, she needed supervision to minimal assistance in all selfcare activities and was able to ambulate sIowly with a quad-stick
under close supervision. No significant improvement of her neurological status was observed. On review 1 year after the intracranial
bleed, there were no further neurological events and her functional
status was unchanged.

DISCUSSION

Fig 2 - - C T scan brain showing large right frontoparietal haem.
atoma with midline shift.
consistent with a mycotic aneurysm. Even though the echocardiographic examination was negative for vegetations and six consecutive blood cultures were negative for bacteria growth, she was
treated for bacterial endocarditis with antibiotics for 6 weeks, in
view of the other clinical and laboratory findings. Six weeks after
admission, she was transferred to rehabilitation for further management. Clinically, there was a left hemiparesis, left homonymous
hemianopia, left neglect, and visuospatial deficits. Cognitive testing
also showed difficulties in the planning, sequencing, and organization of tasks. Functionally, she needed assistance in all self-care
activities and.was only able to ambulate with moderate assistance.
An intensive rehabilitation program consisting of physiotherapy,
occupational therapy and cognitive therapy with emphasis on compensatory measures was started. Functional improvements were
made and by the time of discharge 6 weeks after rehabilitation,
she was independent in all her self-care activities except for bathing
and toileting whereby minimal to moderate assistance was needed.
She was able to ambulate under supervision with the assistance of
an ankle-foot orthosis and a walking stick. On outpatient review
2 years after the intracranial bleed, she was functionally the same.
No further intracranial events were noted.
CASE 2
This previously well 22-year-old female clerk with known mitral
valve prolapse and mitral regurgitation was admitted for fever
and lethargy. Echocardiographic examination of the heart showed
vegetations and three consecutive blood cultures grew alpha-streptococci. The diagnosis of bacterial endocarditis was made and she
was started on antibiotics. Twelve days after antibiotic therapy,
she developed headache; vomiting, progressive drowsiness, and a
left hemiplegia. CT brain scan showed a large right frontoparietal
hemorrhage with midline shift (fig 2). As the patient's condition
deteriorated, an emergency craniotomy was performed. Intraoperatively, two mycotic aneurysms were observed along the branches
of the middle cerebral artery and one had ruptured giving rise to
the frontoparietal hemorrhage. Evacuation of the clot and excision
of both aneurysms were performed.
Arch Phys Med Rehabil Vol 76, March 1995

M a n y intracranial mycotic aneurysms are asymptomatic
till rupture occurs. Rupture is usually a catastrophic event
with a fatality rate of 80%. 8 It can produce either subarachnoid hemorrhage, intraventricular hemorrhage, or more commonly, direct intracerebral destruction o f the brain itself.
Aneurysmal rupture m a y be the first presentation o f infective
endocarditis and this is more c o m m o n in acute endocarditis
where aneurysm formation occurs earlier, compared with
subacute infective endocarditis where aneurysm formation
occurs more frequently but at a later stage o f the disease. 9'1°
Occasionally, there may be cranial nerve involvement secondary to compressive effects from an enlarging aneurysm
or signs o f meningeal irritation m a y develop from a slowly
leaking aneurysm. Intracranial hemorrhage in infective endocarditis can also result from septic erosion of the arterial
wall with rupture but without a well-delineated aneurysm 1°
or from hemorrhagic transformation of ischemic brain infarcts especially in those who are anticoagulated. 11'12
Embolisation of septic embolic material to cerebral vessels is necessary for the development o f infective aneurysm.
Molinari and coworkers, in animal studies of septic cerebral
embolization noted the formation of infective aneurysms as
early as 3 days when antibiotics were not given. 13 With
antibiotic treatment, aneurysm formation occurred at 7 to
10 days. It was also shown that the inflammatory response
proceeded from the adventitial surface toward the media,
with the internal elastic membrane and intima being affected
last. The middle cerebral artery is involved most often, about
4 times more often than either the anterior or posterior cerebral artery. The aneurysms are typically sited at the bifurcation of small secondary branch peripheral arteries and they
can be single or multiple, s
CT scan of the brain apart from showing intracerebral or
subarachnoid hemorrhage does not usually show the diagnosis of infective aneurysm. Angiography is still the ultimate
means for establishing diagnosis. Given the high mortality
rate of aneurysmal rupture, it has been recommended that
routine CT scan and 4-vessel angiogram be performed for
any patient with known infective endocarditis who develops
a neurological deficit suggestive of embolization. ~4
Management of the intracranial infective aneurysm is dependent on factors like the presence or absence of hemorrhage, anatomic location, and clinical course. Healing of

INTRACRANIAL MYCOTIC ANEURYSM, Kong
infective aneurysms with antibiotic treatment is well documented and the indications for surgical intervention must be
evaluated on an individual basis. 15'16 Serial follow-up of the
aneurysm by angiography and more recently, magnetic resonance imaging (MRI), and sequential CT scan has been recommended while patients are still on antibiotic treatment. 17
The functional outcome of patients surviving rupture of
intracranial infective aneurysms is not well documented.
Bohmfalk 4 in his review of 19 survivors of ruptured infective
aneurysms defined outcome as either partially recovered or
completely recovered, whereas Frazee ~8 in his series of 7
survivors defined outcome as normal or disabled. The functional outcome of the 2 reported cases here was deemed to
be less than satisfactory as on discharge, both still needed
supervision and assistance in some basic self-care activities
and mobility. Much of this is because of the presence of
cognitive impairment and perceptual problems secondary to
right hemispheric involvement. It is very likely that the functional outcome of patients with ruptured intracranial infective aneurysms is closely dependent on the degree of cerebral
damage secondary to the hemorrhage. As most aneurysms
are sited in the middle cerebral circulation, rupture inevitably
results in intralobar hemorrhage and destruction. As a result,
cortical neurological deficits like dysphasia, dyspraxia,
hemianopia, perceptual, and cognitive deficits are not uncommon depending on the side and site of hemorrhage. The
rehabilitation team should be cognizant of the frequency of
these deficits because of their adverse effects on functional
outcome. ~9
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