Dear Editor,

In the March 2009 edition, Friedman et al presented the case of a 75- year-old man with acute onset of dysarthria, facial droop and right conjugate eye deviation (CED) that could not be overcome by the oculocephalic maneuver (gaze preference) (1). CT, CTA and CTP of the brain confirmed a discrete right middle cerebral artery infarct. The NIH Stroke Scale was 5 and the patient did not receive thrombolytic medication. He went on to a full recovery.

The author cites Tijssen et al who found that in patients with acute cerebral infarct, those presenting with CED had a worse prognosis than those without CED (2). Friedman and colleagues reported their case as an exception to the expected poor prognosis.

In the study by Tijssen et al, right sided CED occurred more frequently than left (65% to 35%). Additionally, mortality was 64% higher in left sided CED than right. In a follow up study, Tijssen et al quantified the volume of cerebral infarct using head CT 7-10 days after the stroke. They found that the mean stroke volume with left hemispheric CED was 1.5 times the mean stroke volume with right hemispheric CED (3). Similarly, Singer et al reported that the volume of MRI diffusion weighted imaging defined infarct was smaller in right CED compared to left CED; i.e., a smaller volume of infarct was required to cause CED on the right than on the left. (4)

Friedman and colleague’s assessment that this patient’s full recovery represents an exception to the poor prognosis does not take into account the laterality of the lesion. Right-sided infarcts with CED have a better prognosis than left sided lesions. This is most likely due to the larger infarct volume found in left sided CED. When using CED as a prognostic tool in acute cerebral infarct, it is important to consider the side of the lesion and size of the infarct.

REFERENCES

1. Friedman Y, Pettersen JA, Aviv RI, Murray BJ.
The "eye sign" in acute stroke: not necessarily poor outcome.
Journal of Neurology, Neurosurgery, and Psychiatry 2009;80:291.

2. Tijssen CC, Schulte BP, Leyten AC.
Prognostic significance of conjugate eye deviation in stroke patients.
Stroke. 1991 Feb; 22(2): 200- 2.

3. Tijssen CC, van Gisbergen JA, Schulte BP.
Conjugate eye deviation: side, site, and size of the hemispheric lesion.
Neurology. 1991 Jun; 41(6): 846-50.

4. Singer OC, Humpich MC, Laufs H, Lanfermann H, Steinmetz H, Neumann -Haefelin T.
Conjugate eye deviation in acute stroke: incidence, hemispheric asymmetry, and lesion pattern.
Stroke. 2006 Nov; 37(11): 2726 -32.