Low T3 syndrome predicts severe neurological deficits of cerebral infarction inpatients with large artery artherosclerosis in internal carotid artery system.

OBJECTIVES: The low triiodothyronine (T3) syndrome indicates poor prognosis for patients with cerebral infarction. It is unknown, however, whether basic conditions or severities in the patients with the low T3 syndrome are different compared to those without the low T3 syndrome. METHODS: We compared the risk factors and the severity of the disease using the National Institutes of Health stroke scale (NIHSS) score at the worst condition for cerebral infarction in patients with or without the low T3 syndrome in order to better understand the characteristics underlying the worse prognosis in patients with the low T3 syndrome. RESULTS: We found that cerebral infarction patients with the low T3 syndrome were significantly older (p<0.001) and significantly more likely to be female (p=0.002) and had hypertension (p=0.04) or homocystinemia (p=0.001), but less likely to smoke (p=0.008), compared to patients without the low T3 syndrome. The proportion of NIHSS score ≥8 in the patients with LAA-ICA-associated cerebral infarction accompanied by the low T3 syndrome was significantly higher than in those without the low T3 syndrome (p=0.001). CONCLUSION: We concluded that increased numbers of risk factors for cerebral infarction and more severe neurological deficits may be important causes for worse prognosis in the patients with the low T3 syndrome which may more likely occur in patients with LAA-ICA cerebral infarction. Intense secondary prevention in cerebral infarction especially in older women are needed.