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J Neurosurg 101:546, 2004

Ictal bradycardia after endovascular treatment of an aneurysm
Case illustration
BOBY V. MARAMATTOM, M.D., D.M., JEFFREY W. BRITTON, M.D., GENA R. GHEARING, M.D.,
AND EELCO F. M. WIJDICKS, M.D.
Divisions of Critical Care Neurology, Neurological-Neurosurgical Intensive Care Unit; and Clinical Neurophysiology-EEG and
Epilepsy, Saint Mary’s Hospital, Mayo Clinic College of Medicine, Rochester, Minnesota
KEY WORDS

•

aneurysm •

coil embolization

• bradycardia

Seizures as a cause of bradycardia are rarely considered in the
neurosurgical intensive care unit (NICU) and may only be diagnosed
with simultaneous electrocardiography (EKG) and electroencephalography (EEG) monitoring.
This 67-year-old woman presented to us 1 week after having undergone Guglielmi Detachable Coil embolization of a left supraclinoid internal carotid artery aneurysm. She had experienced two to
three episodes of seizures along with severe bradycardia (heart rate
20 bpm). There was no history of cardiac illness or use of cardioactive drugs. On examination, she had a Glasgow Coma Scale score
of 15 and mild conductive aphasia. Magnetic resonance studies revealed hyperintensities on T2-weighted images in the left temporal
lobe and left basal ganglia, with the aneurysm abutting the temporal
lobe on coronal images (Fig. 1). She was started on a regimen of sodium valproate.
Simultaneous video EKG/EEG monitoring recorded a left temporal lobe seizure accompanied by severe bradycardia lasting 53 seconds (Fig. 2). The lowest heart rate recorded during monitoring was
22 bpm. The patient refused to undergo implantation of a cardiac

•

seizure

FIG. 2. Simultaneously obtained EKG/EEG tracings showing the
sudden appearance of left temporal lobe activity followed by bradycardia.
pacemaker. She has experienced no other seizure during a 1-year follow-up period.
Ictal arrhythmias presumably develop from the propagation of
seizure activity to the central autonomic network (CAN), which regulates autonomic visceromotor output.1 The CAN consists of the
insular cortex, amygdala, central nuclei, and portions of the hypothalamus. Cardiac pacing may be indicated because seizures are refractory to medication in 40% of patients and bradyarrhythmias are
potentially fatal.2 Ictal bradycardia may occur in left hemisphere or
temporal lobe seizures.3,4 To our knowledge, this is the first report of
ictal bradycardia following endovascular therapy for an aneurysm.
The contents of this report emphasize the importance of considering
an ictal cause of bradycardia in patients in the NICU.
References

FIG. 1. Coronal MR image demonstrating an internal carotid artery
aneurysm abutting the temporal lobe. The abnormal signal in the left
temporal lobe is partially obscured by a coil artifact. Note also the
small infarct in the subcortical parietal lobe.

1. Benarroch EE: Central Autonomic Network: Functional Organization and Clinical Correlations. Armonk, NY: Futura, 1997,
pp 3–28
2. Liedholm LJ, Gudjonsson O: Cardiac arrest due to partial epileptic seizures. Neurology 42:824–829, 1992
3. Reeves AL, Nollet KE, Klass DW, et al: The ictal bradycardia syndrome. Epilepsia 37:983–987, 1996
4. Tinuper P, Bisulli F, Cerullo A, et al: Ictal bradycardia in partial
epileptic seizures: autonomic investigation in three cases and literature review. Brain 124:2361–2371, 2001

Manuscript received December 1, 2003; accepted in final form May 14, 2004.
Address reprint requests to: Eelco F. M. Wijdicks, M.D., Department of Neurology, Mayo Clinic, W8B, 200 First Street NW, Rochester,
Minnesota 55905. email: Wijde@mayo.edu.

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J. Neurosurg. / Volume 101 / September, 2004