In addition to the above CNS pathways, the brainstem gives rise to most of the twelve cranial nerves. A brainstem stroke affecting the brainstem and brain, therefore, can produce symptoms relating to deficits in these cranial nerves:
altered smell, taste, hearing, or vision (total or partial)
drooping of eyelid (ptosis) and weakness of ocular muscles
decreased reflexes: gag, swallow, pupil reactivity to light
decreased sensation and muscle weakness of the face
balance problems and nystagmus
altered breathing and heart rate
weakness in sternocleidomastoid muscle with inability to turn head to one side
weakness in tongue (inability to stick out the tongue or move it from side to side)If the cerebral cortex is involved, the CNS pathways can again be affected, but also can produce the following symptoms:

aphasia (difficulty with verbal expression, auditory comprehension, reading and writing;  Brocas or Wernickes area typically involved)
dysarthria (motor speech disorder resulting from neurological injury)
apraxia (altered voluntary movements)
visual field defect
memory deficits (involvement of temporal lobe)
hemineglect (involvement of parietal lobe)
disorganized thinking, confusion, hypersexual gestures (with involvement of frontal lobe)
lack of insight of his or her, usually stroke-related, disabilityIf the cerebellum is involved, ataxia might be present and this includes:

altered walking gait
altered movement coordination
vertigo and or disequilibrium

Associated symptoms
Loss of consciousness, headache, and vomiting usually occur more often in hemorrhagic stroke than in thrombosis because of the increased intracranial pressure from the leaking blood compressing the brain. If symptoms are maximal at onset, the cause is more likely to be a subarachnoid hemorrhage or an embolic stroke. Causes
Thrombotic stroke
In thrombotic stroke, a thrombus (blood clot) usually forms around atherosclerotic plaques.
Low doses of aspirin (for example 75–150 mg) are as effective as high doses but have fewer side effects; the lowest effective dose remains unknown. Thienopyridines (clopidogrel, ticlopidine) might be slightly more effective than aspirin and have a decreased risk of gastrointestinal bleeding, but are more expensive. Both aspirin and clopidogrel may be useful in the first few weeks after a minor stroke or high risk TIA. Clopidogrel has less side effects than ticlopidine. Dipyridamole can be added to aspirin therapy to provide a small additional benefit, even though headache is a common side effect. Low-dose aspirin is also effective for stroke prevention after having a myocardial infarction.Those with atrial fibrillation have a 5% a year risk of stroke, and this risk is higher in those with valvular atrial fibrillation. Depending on the stroke risk, anticoagulation with medications such as warfarin or aspirin is useful for prevention. Except in people with atrial fibrillation, oral anticoagulants are not advised for stroke prevention—any benefit is offset by bleeding risk.In primary prevention, however, antiplatelet drugs did not reduce the risk of ischemic stroke but increased the risk of major bleeding. Further studies are needed to investigate a possible protective effect of aspirin against ischemic stroke in women. Surgery
Carotid endarterectomy or carotid angioplasty can be used to remove atherosclerotic narrowing of the carotid artery. There is evidence supporting this procedure in selected cases. Endarterectomy for a significant stenosis has been shown to be useful in preventing further strokes in those who have already had one.