To examine the link between neutrophil lymphocyte ratios on presentation and atherosclerotic stroke in a young cohort.

Stroke is a leading cause of death and morbidity internationally. TOAST criteria is often used to classify ischaemic stroke aetiology, and is well established in the literature.

Inflammation has been strongly linked with stroke especially stroke secondary to atherosclerosis. Neutrophil to lymphocyte ratios (NLR) reflect adaptive and innate immune responses and have been shown to be high in patients with intracranial atherosclerosis. Despite rising incidence internationally, data on young stroke (stroke affecting people under 66-years) is limited.

We sought to assess the link between NLR on presentation and atherosclerotic stroke in a young cohort.

Data on young strokes between January 2015 and September 2019 was collected. We gathered details on age, TOAST classification and admission NLR.

We defined high NLR to be NLR >2.66, the median value in our study. A low NLR was <2.66. We also split our stroke aetiologies into atherosclerosis (small vessel and large vessel atherosclerosis from TOAST classification) and stroke not related to atherosclerosis (a combination of cardioembolic, cryptogenic and strokes related to other causes).

The NLR was then compared between both groups.

Our hospital had 227 young stroke patients over the four year period.

60 patients were female.

Median age was 55 years; age range was 23 years to 65 years.

A high NLR was seen in 40 patients (48%) presenting with atherosclerotic stroke and low NLR in 44 (52%).

High NLR was seen in 72 (52%) and low NLR in 67 (48%) of patients with stroke unrelated to atherosclerotic disease.

Our data shows that admission NLR does not indicate atherosclerosis as stroke mechanism. Although NLR has been linked to intracranial atherosclerosis in general stroke populations, this does not appear to be true for our young stroke population.