Study of Carotid doppler in Patients with ischemic stroke

Introduction: Stroke is one of the major causes of increased morbidity and death. Large-vessel atherosclerosis of intracranial and extra cranial carotid vessels is an important cause of ischemic stroke. This research was undertaken to study the carotid Doppler findings in patients with acute ischemic stroke. Methods: A hospital-based prospective cross-sectional study was conducted from January 2020 till December 2020 in the department of Radio diagnosis and Imaging at Manipal Teaching Hospital, Pokhara, Nepal. Neuro-imaging and carotid Doppler findings in patients with ischemic stroke were studied. Data analysis was done using SPSS 20. Results: The mean age of subjects with ischemic stroke was 64 ± 13.4 years with the majority of cases in the age group of 51-70 years of age with male predominance (M: F= 3: 2). Lacunar infarcts (34.2%) were the most common findings followed by MCA infarct (30%) and ACA infarct (10.8%). Carotid plaques were seen in 43.3% patients. Bilateral ICA atheromatous plaque was seen in 48.1% of patients. Carotid bulb was the common site for plaque formation. Type III plaque was the commonest type. Significant ICA stenosis > 50 % was observed in 24.2% patients. Age >50 years, male sex, smoking, hypertension, diabetes, and hyperlipidemia were important risk factors. Conclusion: Carotid artery Doppler demonstrated atherosclerotic plaques and significant stenosis in patients with ischemic stroke. Increasing age >50 years, male sex, smoking, hypertension, diabetes, and hyperlipidemia were associated with an increased rate of atherosclerosis, carotid stenosis and ischemic stroke.

patient or patient relatives.
The sample size was collected using the formula, n= 4x p x q /e2 Where p= prevalence q= 1-p e= margin of error (0.05 i.e. 5%) From a previous multicentre, large study comprising of 2096 patients, the prevalence of extra cranial Internal Carotid artery stenosis leading to ischemic stroke was 8.0% . 7 So, sample size n = (4 x 8 x 92)/25 = 117 The calculated minimum sample size was 117. A total of 120 cases were taken over a period of 12 months which was the sample size adequate for the study.
All patients aged more than 18 years who presented with clinical features of stroke and showed evidence of no hemorrhage (i.e., ischemia) in CT / MRI were enrolled in the study. History, physical examination, and data considering demographic variables and clinical findings at presentation were collected. Risk factors such as hypertension, diabetes mellitus, dyslipidemia, smoking, including history of TIA or previous ischemic stroke were also documented.
All scans were performed by LOGIQ P3 by Wipro GE Ultrasound equipment using a high frequency 5-12 MHz probe for evaluation of the extra cranial carotid arteries.
The examination was performed after taking their informed consent. The study was carried out using realtime ultrasound equipment capable of B-mode imaging, pulsed-wave duplex scanning, and colour Doppler flow imaging and power Doppler imaging. The patient was placed in supine or semi-supine with head slightly hyper extended and rotated 45° away from the side being examined. The scan was done in both transverse and longitudinal plane and common carotid artery, bulb, ECA, and ICA were examined bilaterally. On the carotid Doppler study, the studied parameters were Peak systolic velocity (PSV) of Internal carotid artery ICA, plaque characteristics, and grading of carotid artery stenosis (diameter stenosis). All the examinations were performed by the same operator with a Doppler angle of < 60°.
The patients underwent computed tomography (CT) scan and/or MRI of Brain prior to the color Doppler sonography of carotid arteries and various findings like the side of infarct (right/left), vascular territory (Middle cerebral artery/anterior cerebral artery/posterior cerebral artery) were noted. All consecutive patients with ischemic stroke were included in the study. Patients with haemorrhagic stroke, head injuries, other causes of cerebral edema, and space-occupying lesions in the brain, those with incomplete records or who fail to give informed consent were excluded from the study.
Data were collected covering all the relevant parameters for the study. All categorical data including findings on Carotid Doppler were expressed in percent and absolute number. All numerical continuous data were expressed in mean ±SD. Chi squared test was used to compare the significant difference of proportions for categorical data.
All tests were analyzed with a 95% confidence interval and were considered statistically significant if p value was <0.05. Statistical Packages for the Social Sciences (SPSS) 20 was used for data analysis.

Results:
A total of 201 patients presented with stroke and underwent CT or MRI in the department of Radio diagnosis and Imaging during the study period. One hundred and thirty-two patients with stroke were detected with non-haemorhage in CT/ MRI demonstrating that 65.7% of strokes were infarct or were of ischemic origin. Twelve patients were excluded from the study due to incomplete data and records. So, finally, 120 cases were taken up for the study. The study group comprised of 72 (60%) males and 48 (40%) females (M: F=3:2). The mean age of subjects was 64 ± 13.4 years with a range of 36 -88 years of age.
Patients were classified as per sex and age groups ( Table   1). The majority (n=64; 53.3%) of cases were aged between 51-70 years of age. Nine (7.5%) were young stroke patients, aged <40 years. There was no statistical significant difference in occurrence of stroke among two genders in different age groups (p=0.85; p>0.05).    and type I (uniformly hypoechoic) was least common (n=9; 11.7%). In our study none of the patient showed plaque ulceration and hemorrhage.

Discussion:
The prevalence of ischemic stroke was 65.7% in the present study. It was almost similar 68% in the previous Nepalese study by Pathak