Stroke symptoms typically start suddenly, over seconds to minutes, and in most cases don't progress further. The symptoms depend on the area of the brain affected. The more extensive the area of brain affected, the more functions that are likely to be lost. Some forms of stroke can cause additional symptoms: in intracranial hemorrhage, the affected area may compress other structures. Most forms of stroke are not associated with headache, apart from subarachnoid hemorrhage and cerebral venous thrombosis and occasionally intracerebral hemorrhage.

Early recognition

Various systems have been proposed to increase recognition of stroke by patients, relatives and emergency first responders. Sudden-onset face weakness, arm drift, and abnormal speech are the findings most likely to lead to the correct identification of a case of stroke Proposed systems include FAST (face, arm and speech test), the Los Angeles Prehospital Stroke Screen (LAPSS) and the Cincinnati Prehospital Stroke Scale (CPSS). Use of these scales is recommended by professional guidelines.

For people referred to the emergency room, early recognition of stroke is deemed important as this can expedite diagnostic tests and treatments. A scoring system called ROSIER (recognition of stroke in the emergency room) is recommended for this purpose; it is based on features from the medical history and physical examination.

Subtypes

If the area of the brain affected contains one of the three prominent Central nervous system pathways—the spinothalamic tract, corticospinal tract, and dorsal column (medial lemniscus), symptoms may include:

• hemiplegia and muscle weakness of the face

• numbness

• reduction in sensory or vibratory sensation

In most cases, the symptoms affect only one side of the body (unilateral). The defect in the brain is usually on the opposite side of the body (depending on which part of the brain is affected). However, the presence of any one of these symptoms does not necessarily suggest a stroke, since these pathways also travel in the spinal cord and any lesion there can also produce these symptoms.

In addition to the above CNS pathways, the brainstem also consists of the 12 cranial nerves. A stroke affecting the brain stem 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 protrude and/or move 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 (inability to speak or understand language from involvement of Broca's or Wernicke's area)

• 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)

• anosognosia (persistent denial of the existence of a, usually stroke-related, deficit)

If the cerebellum is involved, the patient may have the following:

• trouble walking

• altered movement coordination

• vertigo and or disequilibrium