The posterior cerebral arteries (PCAs) are the major sources of blood supply to the midbrain, thalamus, occipital lobes, inferior and medial temporal lobes, and portions of the posterior inferior parietal lobes. The PCAs originate from the terminal bifurcation of the basilar artery, encircle the midbrain, and then divide into cortical branches as they reach the dorsal surface of the midbrain. Patients with PCA stenosis may have transient ischemic attacks (TIAs) alone, or they may precede infarction. The main clinical feature distinguishing proximal PCA occlusion from the other types of PCA strokes is hemiplegia. Unilateral and bilateral PCA territory infarctions can also result from mass lesions that cause transtentorial herniation and increased intracranial pressure. The temporal and calcarine artery branches are most often involved. Patients with bilateral infarctions involving the lingual and fusiform gyri in the inferior portions of the temporal lobes often manifest a restless, hyperactive state.

The most common cause of paroxysmal paresis of one side of the body with or without other associated symptoms is transient cerebral ischemia. The majority of patients with a paroxysmal paresis need a cerebral imaging. In the initial phase of encephalitis, transient focal neurological symptoms occur including paresis which poses like transient ischemic attacks (TIA). Acute paraparesis or paraplegia consists in most cases in incomplete or complete paresis of the legs. The rare paresis of both arms is called diplegia brachialis. In patients with acute teraparesis or tetraplegia, the first differential diagnosis is a spinal lesion in the upper part of the cervical spine. Associated are commonly sensory symptoms and bladder or bowel function disturbance. In cases of an acute paresis of one extremity or even only singular muscle groups of one extremity, a monoparesis or monoplegia is present depending on the fact if the paresis is incomplete or complete.

The risk of recurrence of stroke in patients with systemic lupus erythematosus (SLE) is much higher than in other stroke patients, and the preventative treatment is influenced by the underlying systemic disease. Microinfarcts and microhemorrhages are seen frequently in autopsy specimens of SLE patients. Asymptomatic microinfarcts are common, and are now diagnosed due to the high sensitivity of MRI. Occlusions of large arteries and major strokes also occur in lupus patients. Atherosclerosis may be more frequent in SLE patients than in the general population. The major causes of stroke in lupus are cardiogenic emboli and hypercoagulable (including hypofibrinolytic) states, and the mainstay of stroke prevention is long-term warfarin, with an international normalized ratio (INR) of approximately 3.0. Although stroke is an important problem in lupus patients, leading to significant morbidity in young patients, SLE is relatively uncommon in young patients presenting with strokes or transient ischemic attacks (TIAs).

The US asymptomatic carotid atherosclerosis study first reported reduction in stroke rate after prophylactic carotid endarterectomy. Four large randomized trials have now been reported suggesting that carotid endarterectomy for asymptomatic disease can prevent stroke. The US Veterans Administration hospitals' trial reported that 4 years after prophylactic carotid endarterectomy patients with asymptomatic carotid stenosis of 50-99% had significantly fewer transient ischemic attacks (TIA) and strokes than controls. The asymptomatic carotid surgery trial (ACST) is the largest vascular trial to date. Trials suggest that selected patients with asymptomatic disease will benefit from carotid endarterectomy. Appropriate screening populations could include patients attending vascular clinics, patients with contralateral symptomatic stenoses or disease in another vascular bed. A more recent study of combined or staged carotid endarterectomy and coronary artery bypass graft (CABG) in patients with asymptomatic carotid disease suggests that the perioperative stroke risk compares favorably with CABG alone.