RIND_Dec2010_p157.qxd 12/14/10 2:35 PM Page 157
CASE REVIEW: DISCUSSION
A Late Complication of Knife
Radiosurgery
Ted L. Rothstein, MD
Department of Neurology, George Washington University, Washington, DC
[Rev Neurol Dis. 2010;7(4):157-159 doi: 10.3909/rind0252b]
© 2010 MedReviews®, LLC
Key words: Intracerebral hemorrhage • Late-term complication • Stereotactic radiosurgery •
knife radiosurgery
The following is a discussion of the case presented on pages 150-151 of this issue.
O
n initial presentation, a computed tomography
(CT) brain scan revealed a 20-mm 22-mm left
thalamic hemorrhage surrounding the site of previously performed knife stereotactic radiosurgery. The
hemorrhage was multilayered with surrounding vasogenic edema, giving the lesion the appearance of a bull’seye (Figure 1).
The morning after admission the patient became more
obtunded and profoundly weak in the right arm and leg.
He had developed rales in both lungs. A repeat CT brain
scan disclosed enlargement of the left thalamic hemorrhage to 22 mm 29 mm with greater mass effect upon
the third and lateral ventricles. He was found to have
extensive left pneumonic infiltrates involving all segments
and was placed on ceftizoxime. He became progressively
unresponsive and died on the sixth hospital day.
There has been renewed interest in neurosurgical
approaches to movement disorders resulting from
improved understanding of the neurophysiology of the
basal ganglia and thalamus, more accurate brain imaging
techniques, and more refined surgical techniques and
stereotactic procedures resulting in decreased surgical
morbidity and mortality.
Knife stereotactic radiosurgery (GKSR) is a minimally
invasive neurosurgical technique that has been used to
lesion the subthalamic nucleus, globus pallidus, or thalamus to treat movement disorders including benign
familial tremor and Parkinson disease. Knife thalamotomy has been considered a safe and effective alternative
to deep brain stimulation for the treatment of benign
essential tremor. However, there have been a small number of reports describing complications due to GKSR, and
long-term complications tend to be underreported.1
Most complications of GKSR have been related to postradiation edema and delayed radiation necrosis.2 Stroke
as a post-radiosurgical complication has been reported in
a number of articles.1-3
Okun and colleagues1 describe 8 patients referred to
their tertiary center over an 8-month period for complications of GKSR. One patient died after developing
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A Late Complication of Knife Radiosurgery continued
Figure 1. Computed tomography brain scan revealing a 2-cm round hemorrhagic
hyperdensity at the lateral aspect of the left thalamus with moderate surrounding
vasogenic edema producing a lesion that resembles a bull’s-eye.
dysphagia and aspiration; other complications included
hemiplegia, homonymous field defect, hand weakness,
dysarthria, hypophonia, aphasia, face and arm paresthesias, and pseudobulbar laughter. In each of these patients
the complications were attributed to missing the intended target and damaging adjacent structures. The case
report by Friedman and coworkers2 describes a 66-yearold man who underwent knife pallidotomy for
Parkinson disease and experienced a stroke proven at
autopsy to be due to radiation vasculopathy.
The experience using GKSR for arteriovenous malformation (AVM) provides additional support for intracere-
The experience using GKSR for arteriovenous
malformation provides additional support for intracerebral ischemic or hemorrhagic stroke as a long-term
complication.
bral ischemic or hemorrhagic stroke as a long-term complication. Yamamoto and associates3 describe a patient
with a radiosurgically treated pontine AVM who developed a pontine hemorrhagic stroke 47 months after angiographically confirmed nidus obliteration (71 months
after irradiation). The hemorrhage occurred close to the
treated nidus.
Douglas and Goodkin4 reviewed their experience with
95 patients (with 99 treatable AVMs) at the University of
Washington (Seattle, WA) from 2000 through 2005. They
reported 2 fatal and 13 nonfatal intracerebral hemorrhages after GKSR.
Yamamoto and colleagues5 examined the neuropathologic findings of a patient who died of unrelated causes,
who had previously been treated with GKSR and was
found to have intimal hypertrophy in normal (AVMunrelated) pial arteries with fragmentation of the elastic
laminae and occlusion of some vessels within the field of
irradiation.
Perhaps more relevant to the patient described here is
the case report by Kurita and colleagues,6 which describes
a patient treated for an intracerebral AVM developed progressive neurologic deterioration from an expanding
hematoma 2 years after receiving GKSR. A tough capsule
containing multiple layers of organized hematoma
resulting from previous bleeding was confirmed surgically. Histologic examination revealed a collagenous
outer layer and granulomatous newly vascularized inner
layers with marked fibrosis.
Although late-term complications of GKSR are uncommon, the location of the hemorrhage in the patient
reported here suggests that previous destruction of
brain parenchyma and vasculature contributed to the
intracerebral hemorrhage.
Conclusions
Presented here is the case of an anticoagulated elderly
man who died following an intracerebral hemorrhage
at the site of a thalamic lesion, produced by GKSR,
which was provided as therapy for an essential tremor.
Hemorrhagic stroke as a long-term complication must be
considered as a risk factor when using GKSR.
Main Points
• An elderly patient developed a thalamic hemorrhage at the precise location of a knife radiosurgical lesion performed
7.5 years earlier.
• Destruction of brain parenchyma and vasculature from a radiosurgical lesion renders brain tissue vulnerable to subsequent hemorrhage.
• Hemorrhagic stroke is a long-term complication of knife radiosurgery.
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A Late Complication of Knife Radiosurgery
References
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Okun MS, Stover NP, Subramanian T, et al. Complications of gamma knife
surgery for Parkinson disease. Arch Neurol. 2001;58:1995-2002.
Friedman JH, Fernandez HH, Sikirica M, et al. Stroke induced by gamma
knife pallidotomy: autopsy result. Neurology. 2002;58:1695-1697.
Yamamoto M, Jimbo M, Hara M, et al. Gamma knife radiosurgery for
arteriovenous malformations: long-term follow-up results focusing on
complications occurring more than 5 years after irradiation. Neurosurgery.
1996;38:906-914.
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5.
6.
Douglas JG, Goodkin R. Treatment of arteriovenous malformations using
Gamma Knife surgery: the experience at the University of Washington from
2000 to 2005. J Neurosurg. 2008;109(suppl):51-56.
Yamamoto M, Jimbo M, Ide M, et al. Gamma knife radiosurgery for cerebral arteriovenous malformation: an autopsy report focusing on irradiation-induced
changes observed in nidus-unrelated arteries. Surg Neurol. 1995;44:421-427.
Kurita H, Sasaki T, Kawamoto S, et al. Chronic encapsulated expanding
hematoma in association with gamma knife surgical radiation for a cerebral
arteriovenous malformation: case report. J Neurosurg. 1996;84:874-878.
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