Evidence for more widespread cerebral pathology in early HD: An MRI-based morphometric analysis

To the Editor: Simon et al.1 evaluated the frequency of CTassessed conjugate eye deviation (CED) toward the affected hemisphere in a consecutive series of acute stroke patients treated with recombinant tissue plasminogen activator (rt-PA). CED was observed in 43% of patients and a further 33% had a lone abducting eye (LAE). In this study, CED and LAE properly lateralized the side of the affected hemisphere in 81% (29/36) of patients with right hemisphere strokes and in 59% (42/71) of patients with left hemisphere ones, with a right/left ratio of 1.4:1. In a previous study, the clinically assessed CED correctly lateralized the affected hemisphere in 62% of patients with right hemisphere lesions and 38% with left hemisphere ones with a right/left ratio of 1.6:1.2 Of note, in the series of Simon et al.,1 with a 92.1% (106/117) prevalence of anterior circulation strokes, only 33% (35/107) had a right hemisphere lesion. Interestingly, in our series of 175 patients with anterior circulation ischemic strokes treated consecutively with rt-PA, we observed a similar low proportion (39%, n 68) of patients with right versus left lesions.3 Patients with right hemisphere stroke are less likely to be treated with rt-PA due to many factors: 1) the misconception that damage to the right hemisphere affects patients less severely than damage to the left; 2) inadequate knowledge, within the community, of the symptoms and signs of nondominant hemisphere stroke, compared to the familiar language disturbance of the dominant one; 3) some patients with right hemisphere stroke may only show poverty of movements with the left limbs and decreased visual exploration toward the opposite side as part of the neglect, and a tendency to keep the eyes closed due to eyelid apraxia; 4) the lack of a standardized and sensitive tool for assessing and monitoring stroke severity in acute right hemisphere ischemic stroke. The low sensitivity of the National Institute of Health Stroke Scale (NIHSS) in assessing stroke severity in right hemisphere stroke has been demonstrated by perfusion-weighted MRI findings,4 and this may account for the absence of correlation between the presence of CED/LAE and the NIHSS observed by the authors. Unawareness of illness affects recovery: nevertheless, there are no evidence-based data targeting and monitoring the neglect syndrome and its changes after thrombolysis. Hillis et al.5 observed that the administration of the simple line cancellation test is highly sensitive in assessing hemispatial neglect in patients with acute nondominant hemisphere stroke. The authors observed that an improvement in test performance correlated to brain reperfusion. Therefore, the CT-assessed CED, in conjunction with other tests sensitive to nondominant hemispheric function, should be studied in larger series of acute stroke patients in order to optimize the timely identification and treatment of patients with right hemisphere strokes.