Lacunar stroke, also known as lacunar infarction, refers to a type of brain infarction where the diameter of the affected area ranges from 2 millimeters to 15 millimeters. It is treatable, typically caused by atherosclerosis of cerebral arteries leading to ischemia and hypoxia in small capillaries, and subsequently, localized tissue necrosis. These usually occur more frequently beneath the cortical layer of brain tissue, as this area has a dense distribution of small blood vessels and is thus more prone to lacunar infarcts. However, if a lacunar infarct occurs in critical areas such as the thalamus, brainstem, basal ganglia, internal capsule, or the limbs and knee regions within the internal capsule, it can lead to a variety of clinical symptoms. The range and types of these clinical symptoms are diverse, including pure sensory, pure motor, mixed sensorimotor numbness in limbs, and issues with peripheral circulation. Though generally, treatment is relatively quick and straightforward, delays in treatment could lead to more severe clinical symptoms.