Clinical and imaging characteristics of isolated pontine infarction： a comparison between paramedian pontine infarction and lacunar pontine infarction

Abstract

Objective To investigate the clinical and imaging characteristics of isolated pontine infarction as well as the influencing factors for early progressive motor deficits （PMD） and short-term prognosis. Methods A total of 86 patients with isolated pontine infarction who admitted in hospital within 24 hours of symptom onset were analyzed retrospectively. The patients were divided into paramedian pontine infarction （PPI） and lacunar pontine infarction （LPI） according to the maximal diameter of the lesions and the locations of infarction. They were divided into either a PMD group or a non-PMD group according to the early status of PMD. They were also divided into a poor outcome group （mRS score 〉2） and a good outcome group （mRS score ≤ 2） according to the modified Rankin Scale （mRS） scores at discharge. The clinical and imaging features of the different patient groups were compared. Results The patients＇ constituent ratios of hyperlipidemia （57. 14% vs. 33.33% ; g2 = 4. 80, P = 0. 028）, hemiplegia （97. 14% vs. 72. 55% ; X2 = 8. 718, P = 0. 003）, basilar artery stenosis （45. 71% vs. 17. 65%; X2= 7. 930, P= 0. 005） and poor outcome at discharge （54. 29% vs. 31.37% ; X2 = 4. 515, P = 0. 034）, and the baseline National Institutes of Health Stroke Scale （NIHSS） scores （6.00±2.39vs. 4. 61±3.41; t=2.087, P=0.040） in the PPI group （n=35） were significantly higher than those in the LPI group （n = 51）. The constituent ratios of the baseline diastolic blood pressure levels （97. 82 ± 15.61 mm Hg vs. 89. 55 ± 12. 23 mm Hg, 1 mm Hg = 0. 133 kPa; t = 2. 258, P = 0. 031）, PPI （63.64% vs. 32. 81% ;X2 =6. 445, P =0. 011） and basilar artery stenosis （59. 10% vs. 18.75% ; X2 = 12. 922, P =0. 000） in the PMD group （n ---22）were sigtificantly higher than those in the non-PMD group （n =64）. The baseline NIHSS scores （6. 80 ＋ 2. 63 vs. 3.73 ± 2. 55; t = 5.426, P = 0. 000）, fasting blood glucose levels （9. 40 ±5. 15 mmol/L vs. 6. 56 ±2. 69 mmol/L; t =2. 985, P=0. 004） and the constituent ratios of PPI patients （54. 29% vs. 31.37% ; X2 = 4. 515, P = 0. 034） in the poor outcome group （n = 35） were significantly higher than those in the good outcome group （n = 51 ）. Multivariate logistic regression analysis showed that basilar artery stenosis was an independent risk factor for the onset of PPI （odds ratio [ OR ] 3. 801, 95% confidence interval [ CI] 1. 357 - 10. 646; P = 0. 011） and the early PMD of isolated pontine infarction（OR 4.571, 95% CI 1.214- 17.214; P= 0.025）. The baseline NIHSS score ≥ 5 was its independent predictor for poor outcome （OR 4. 277, 95% OR 1. 505 - 12. 151; P =0. 006）. Conclusions PPI is mainly associated with the lesions in the branches of basilar artery. The baseline NIHSS score ≥ 5 may be an independent predictor for short-term poor outcome of isolated pontine infarction. Its early PMD and short-term poor outcome may be associated with the basilar artery lesions. Key words: Brain Infarctions; Pons; Atherosclerosis; Basilar Artery; Magnetic Resonance Imaging; Risk Factors; Progaosis