Aneurysm of the Posterior Cerebral Artery with Unexpected
Postoperative Neurological Deficit
Case Report
WILLIAM E. HUNT, M.D., AND ROBERT M. HESS, M.D.
Division of Neurological Surgery, Department of Surgery, The Ohio State University College of Medicine,
Columbus, Ohio
the posterior cerebral a r t e r y also supply the
ependymal lining of the lateral ventricle,
with the exception of its horns, and the
caudal p a r t of the choroid plexus. 2

ONGENITAL intracranial a n e u r y s m s of
the posterior cerebral a r t e r y t r u n k are
rare. We h a v e seen but one case in our
series of iuore t h a n 300 aneurysms. T h e Cooperative S t u d y of l n t r a c r a n i a l Aneurysms
and Subarachnoid H e m o r r h a g e has reported seven single posterior cerebral maint r u n k a n e u r y s m s in I~,67i single a n e u r y s m
cases, 3 an occurrence of 0 . i 6 % . We know
of no reports of obliterating such a n e u r y s m s
b y trapping.
This is the report of an a n e u r y s m of the
posterior cerebral a r t e r y t r u n k t h a t was
treated successfully b y obliterating the
p a r e n t vessel with v e r y little p e r m a n e n t
neurological deficit.

C

Case Report

Anatomy
N o r m a l l y , the posterior cerebral arteries
are the paired continuations of the basilar
a r t e r y beyond its distal bifurcation. Each
a r t e r y then passes laterally a r o u n d the cerebral peduncle to the postcrolateral aspect of
the midbrain. 4 E a r l y in its course, it gives
origin to the thalamogeniculate arteries and
to the medial and lateral posterior choroidal
arteries. 5 T h e posterior cerebral is then contained in the tentorial incisura until it passes
a b o v e the t e n t o r i u m to the undersurface
of the t e m p o r a l lobe. T h e r e it divides into
two terminal branches, the posterior temporal, and the internal occipital2 A variable
a n d small anterior t e m p o r a l b r a n c h supplies
a portion of the anterior t e m p o r a l lobe. T h e
posterior teml)oral a r t e r y supplies the undersurface of the posterior t e m p o r a l lobe (fusif o r m and lingual gyri). T h e internal occipital
b r a n c h forms the calcarine and parieto-occipital arteries t h a t supply the medial aspect
of the occipital lobe and the precuneus. 4
S o m e authors s t a t e t h a t the cuneus and the
splenium of the corpus callosum are fed b y
these parieto-occipital arteries. Branches of
Received for publication October 31, 1966.

Approximately 1 y e a r before admission,
this 33-year-old white w o m a n consulted a
neurologist because of peculiar sensations of
pain involving the left side of the body, except the face. She had no objective neurological deficit, and no further investigation
was made. F o u r weeks before admission she
had a sudden headache. T h e r e was no loss of
consciousness, seizure, or sensory or visual
disturbance. F o u r t e e n days later, because
the headache persisted, a lumbar puncture
was done. T h e initial pressure was 139 m m of
spinal fluid. T h e fluid was xanthochromic b u t
contained no red cells. T h e total protein was
88 rag%.
Examination. U p o n admission to the University Hospital on M a r c h ~7, 1964, she was
normally developed b u t thin. She was drowsy
and appeared chronically ill. T h e pulse and
respirations were 80 and ~0 per minute respectively, the blood pressure 104/5~ m m
Hg, and the t e m p e r a t u r e 100~ Aside from
mild irritability, no neurological or physical
abnormalities were noted. Visual fields were
examined only b y confrontation. A left
transaxillary, right retrograde vertebral
arteriogram d e m o n s t r a t e d a large saceular
aneurysm of the posterior cerebral a r t e r y
t r u n k (Fig. 1).
Operation. T h r e e d a y s later, through a
right temporoparieto-occipital craniotomy,
the a n e u r y s m was found with its dome
buried within the transverse cerebral fissure
and the infero-medial aspect of the temporal
lobe. The p u l v i n a r was not identified. T h e
parent vessel was clipped b o t h distally and
proximally to the sac. T h e a n e u r y s m was
then aspirated a n d did not refill.
Postoperative Course. I n the immediate

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William E. Hunt and Robert M. Hess

postoperative period, there was a right third
nerve paralysis a n d minimal weakness of the
left a r m a n d leg. At 48 hours, although she
did not have a demonstrable left h o m o n y mous hemianopsia, her visual attention and
acuity seemed to be decreased in the left
h o m o n y m o u s fields.
At 7~ hours, the weakness of the left a r m
and leg was m o r e pronounced and she appeared slightly m o r e drowsy, but again no
clear-cut hemianopsia was detected. I n response to testing she reported a m a r k e d decrease in her awareness of the left side of her
body. A v e r y mild receptive dysphasia was
present. H e r ability to read could not be
tested. Abdominal reflexes were absent on
the left.
At 1~0 hours, there was no evidence of
left hemianopsia, although the left hemiparesis was still manifest. She was mentally clear
enough to d e n y the existence of the left side
of her body.
B y 10 d a y s there h a d been a gradual return of the left b o d y image, and the hemiparesis was a l m o s t undetectable.
On the ~3rd p o s t o p e r a t i v e day, there was
still minimal disturbance of the left body image, an occasional tendency to fall to the
left, and a right third nerve palsy. A repeat
left transbrachial arteriogram showed no evidence of the a n e u r y s m (Fig. ~). T w e n t y seven d a y s a f t e r surgery, the anterior cir-

culation was d e m o n s t r a t e d to be free of
ancurysm.
At the time of her discharge (36th posto p e r a t i v e day), she exhibited an improving
right third nerve palsy, minimal left henriparesis, a n d minimal i m p a i r m e n t of the body
image on the left.
Subsequently, the third nerve palsy and
the sensorimotor hemiparesis recovered completely. Visual fields were plotted a n d were
normal. T h e m o s t persistent residual deficit
was a severe disturbance in spelling which
k e p t her from her job as a publisher's secret a r y for 14, months.
Discussion
T h e ligation of the posterior cerebral art e r y in this instance was deemed necessary as
a life-saving measure. We fully expected a
s t o r m y p o s t o p e r a t i v e course with a perm a n e n t left h o m o n y m o u s hemianopsia.
M o s t physicians describe severe transient
sensorimotor deficit with p e r m a n e n t homony m o u s hemianopsia after occlusion of the
posterior cerebral a r t e r y 3 T h a l a m i c softening with dysesthesia of the contralateral
b o d y and dysynergia due to d e n t a t o - r u b r o t h a l a m i c i n v o l v e m e n t are a t t r i b u t e d to infarctions in the distribution of the t h a l a m o geniculate arteries? T h e s y n d r o m e of the
retrolenticular capsule (hemiplegia, hemianesthesia, a n d hemianopsia) is also attrib-

FIG. 1. Left transaxillary, right retrograde vertebral arteriograms demonstrating right main tru~tk posterior cerebral
artery aneurysm.

A n e u r y s m of t h e P o s t e r i o r C e r e b r a l A r t e r y

635

FiG. ~. Postoperative vertebral arteriograms showing non-filling of the aneurysm sac. Although it cannot be seen in
the photograph, contrast media appeared in the distribution of the medial posterior choroidal artery.

uted to occlusion of branches of the posterior cerebral artery. The good recovery of
function, except for hemianopsia sparing the
macula, is ascribed to good collateral circulation .2
Presumably, collateral circulation for the
internal occipital artery was, in this instance,
adequate. The disturbance in body image
must have reflected ischemia in the deep
parietal lobe and the retrolenticular capsule.
The gnostic disturbance with the peculiar
defect in spelling remains unexplained, unless mixed dominance was present, or unless
ischemia of the splenium of the corpus callosum could play some role in this complex
syndrome.
It is noteworthy that the deficit was transient and that the risk of occluding the posterior cerebral artery was justified in this
case. The postoperative angiogram showed
the occlusion to be distal to both the posterolateral perforators (thalamogeniculate
arteries) and the medial posterior choroidal
artery (Fig. ~). The lateral posterior choroidal arteries were probably sacrificed. The
deficit might have been much more severe
had the parent trunk been occluded closer to
its origin.

Summary
We have reported a case of aneurysm of
the main trunk of the posterior cerebral artery successfully treated by occlusion of
that vessel. We have described the postoperative deficit which was less severe than
anticipated and did not include homonymous
hcmianopsia.
References
1. BAKER, A. B. Clinical Neurology. New York:
Hoeber-Harper, 196~, ~nd ed., 4 vols. (See Vol..%
pp. 593-795)
~. BucY, P. C., GRINKER, n . R., and SAtIs, A. L.
Neurology. Springfield, Ill.: Charles C Thomas, 1960,
5th ed. (See pp. 74~2-743)
3. LOCKSLEY,H.B. Report on the cooperative study of
intracranial aneurysms and subarachnoid hemorrhage. Section V, Part 1. Natural history of subarachnoid hemorrhage, intracranial aneurysms and ateriovenous malformations, based on 6368 cases in the
cooperative study. J. Neurosurg., 1966, 25:~19~39.
4. TAVERAS,J. M., and WOOD, E. It. Diagnostic neuroradiology. Baltimore: Williams and Wilkins, 1964,
961 pp. (See pp. 5~7-5~9)
5. TRUEX, R. C., and CARPENTER, M . B . Strong and
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