Improved visual, acoustic, and neurocognitive functions after carotid endarterectomy in patients with minor stroke from severe carotid stenosis

Objective: Carotid endarterectomy (CEA) is an established operation performed to prevent strokes, but its other potential effects, such as improving neurocognitive, visual, and auditory functions, remain unconfirmed. This study examined these effects of CEA on patients with symptomatic carotid stenosis. Methods: This was a prospective controlled study that included 80 patients with minor strokes who had severe extracranial internal carotid stenoses (>70%). Forty patients, who did not receive or who postponed the CEA due to concerns about age, fear of surgery, limited life expectancy because of cancer, or financial problems, formed the medicine-treatment group. Another 40 patients who received CEA 1 week after recruitment formed the CEA group. For both groups, visual acuity chart tests, perimetry tests, audiometry tests, and neurologic scales (National Institutes of Health Stroke Scale, Mini Mental State Examination, and Barthel Index of Activities of Daily Living) were used to assess ophthalmic functions, auditory acuity, and neurocognitive functions before treatment and 3 months after treatment. Intragroup and intergroup comparisons were conducted to examine the effect of CEA. Results: No deaths or strokes occurred during the 3-month follow-up. The intragroup and intergroup comparisons of ipsilateral function showed that CEA could improve visual acuity, visual field, and auditory acuity at all tested frequencies (250 Hz, 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz) and could improve the visual field and the auditory acuity for contralateral functions at 1000 Hz. The auditory acuity at 2000 Hz and 4000 Hz were unchanged in the intragroup comparison but showed no deterioration in the intergroup comparison with the medicine group. General neurocognitive function and independent living ability were significantly improved by CEA, as shown by intergroup comparisons (change rate of National Institutes of Health Stroke Scale: -8.1% +/- 9.0% vs -2.7% +/- 3.0%, P < .001; change rate of Mini Mental State Examination: 15.5% +/- 10.5% vs 1.6% +/- 2.6%, P < .001; change rate of Barthel Index: 28.0% +/- 24.6% vs 2.0% +/- 5.5%, P < .001). Conclusions: In patients with minor strokes caused by severe carotid stenosis, CEA improves neurocognitive, ophthalmic, and acoustic functions. Studies with a larger sample and longer follow-up are needed to substantiate these results, and the underlying mechanisms need further investigation.