- Clinical science
A stroke is an acute neurologic condition resulting from a disruption in cerebral perfusion, either due to ischemia (ischemic strokes) or hemorrhage (hemorrhagic strokes). Hemorrhagic strokes are further classified as intracerebral or subarachnoid. Systemic hypertension and other cardiovascular diseases are common risk factors for both ischemic and hemorrhagic strokes. Clinically, strokes are characterized by the acute onset of focal neurologic deficits, including hemiparesis, paresthesias, and hemianopsia. The pattern of clinical features is dictated by the affected vessel. Distinguishing between ischemic and hemorrhagic strokes based on physical examination is difficult and requires initial evaluation with a noncontrast head CT. Further neurovascular imaging may be required before deciding on treatment options. In ischemic strokes, immediate revascularization of the affected vessel is vital to preserve brain tissue and prevent further damage. Hemorrhagic strokes are treated with supportive measures and neurosurgical evacuation of blood. Long-term management of all types of stroke focuses on the management of modifiable risk factors (i.e., hypertension and atherosclerosis).
- Stroke: acute neurologic injury caused by ischemia or hemorrhage
- Ischemic stroke: cerebral infarction due to insufficient cerebral blood flow (hypoperfusion), which results in ischemia and neuronal injury
- Transient ischemic attack: temporary, focal cerebral ischemia that results in neurologic deficits without acute infarction or permanent loss of function (previously defined as lasting < 24 hours) 
- Hemorrhagic stroke: cerebral infarction due to hemorrhage
- Intracerebral hemorrhage: bleeding within the brain parenchyma
- Subarachnoid hemorrhage: bleeding into the subarachnoid space
- Intraventricular hemorrhage: bleeding within the ventricles
|Ischemic stroke||Intracerebral hemorrhage||Subarachnoid hemorrhage|
|Epidemiology|| || || |
|Clinical features|| || |
|Diagnosis|| || || |
- ∼ 85%) (
∼ 15%) (
- ∼ 10%) (
- ∼ 5%) (
|Affected vessel||Clinical features |
|Anterior cerebral artery (ACA)|
|Posterior cerebral artery (PCA)|| |
|Posterior inferior cerebellar artery|| |
|Anterior inferior cerebellar artery|| |
|Lenticulostriate arteries (penetrating arteries)|| |
|Extracranial arteries||Internal carotid artery|
|Common carotid artery|
|Anterior spinal artery|| |
Lacunar syndromes 
|Lacunar stroke type||Location||Clinical features|
|Pure motor stroke|
|Pure sensory stroke|| |
|Sensorimotor stroke|| |
|Ataxic hemiparesis|| |
|Dysarthria-clumsy hand syndrome|| |
Infarction of the posterior limb of the internal capsule is the most common type of lacunar stroke and may manifest clinically with pure motor stroke, pure sensory stroke (rare), sensorimotor stroke, dysarthria-clumsy hand syndrome, and/or ataxic hemiparesis.
- Ventral pontine syndrome (Millard-Gubler syndrome): due to basilar artery infarction
Lateral pontine syndrome (Marie-Foix syndrome): due to basilar artery and/or anterior inferior cerebellar artery infarction
- Corticospinal tract: contralateral weakness
- Lateral spinothalamic tract: contralateral loss of pain and temperature sensation
- Cerebellar tracts : ipsilateral limb and gait ataxia
- Cranial nerve nuclei involvement is possible.
- Sympathetic tract : ipsilateral Horner syndrome
- Inferior medial pontine syndrome (Foville syndrome): due to basilar artery infarction
- : occurs with bilateral basilar artery infarction
- Medial midbrain syndrome (Weber syndrome)
- Lateral midbrain syndrome (Claude syndrome)
- Paramedian midbrain syndrome (Benedikt syndrome)
- Dorsal midbrain syndrome (Parinaud syndrome): caused by damage to the dorsal midbrain
- Medial medullary syndrome (Déjerine syndrome): infarct of paramedian branches of the anterior spinal artery
- Wallenberg syndrome) (
Clinical features of strokes affecting other regions
|Location of lesion||Clinical features |
- Primary survey
Clinical assessment and history
- Identify risk factors for ischemic or hemorrhagic stroke, including the presence of carotid bruits.
- Identify signs (above) that indicate the affected vessel and/or region of the brain.
- Determine the time of onset of symptoms (e.g., “last known normal”): The time of stroke onset determines whether thrombolytic therapy is an option (see below).
- Approach: noncontrast head CT to evaluate for acute hemorrhage → diffusion-weighted MRI to detect acute ischemia → consider further neurovascular imaging depending on the type of stroke
- Noncontrast head CT (first-line imaging)
- Allows identification of ischemia earlier than a CT (within 3–30 minutes after onset)
- Allows detection of hyperacute hemorrhage
- Evaluates reversibility of ischemic injury
- Perfusion-weighted imaging (PWI): visualizes areas of decreased perfusion and allows quantification of perfusion parameters, e.g., mean transit time (MTT), cerebral blood flow (CBF) and cerebral blood volume (CBV)
- Perfusion-diffusion mismatch MRI: allows identification of the penumbra (or “tissue-at-risk”)
- See , , and for specific imaging findings and other modalities.
- Initial: serum glucose
- Additional evaluation
Laboratory studies should not delay imaging for patients with acute stroke. 
If symptoms of a suspected ischemic stroke began less than 4.5 hours prior to presentation and there are no signs of intracranial bleeding, begin reperfusion therapy immediately!
Stabilization and monitoring 
- Maintain euvolemia with fluid replacement as needed.
- Maintain a sufficient oxygen supply and consider intubation if the patient shows signs of increased intracranial pressure (e.g., altered mental state).
- Maintain euglycemia (e.g., blood glucose levels within 140–180 mg/dL).
- Maintain normothermia (e.g., antipyretics).
- Cardiac monitoring (for at least 24 hours)
- Maintain a normal acid-base status.
- Electrolyte repletion as needed
- Analgesia as needed
- Monitor for signs of elevated intracranial pressure (see ).
- Seizures should be treated pharmacologically.
- Evaluate for dysphagia.
Blood pressure management 
- Always treat hypotension (e.g., with fluid replacement, vasopressors).
- Ischemic stroke: permissive hypertension
Hemorrhagic stroke: Reduce systolic blood pressure to approx. 140–160 mm Hg.
- See “Treatment” in and .
See , , and for specific management.
Medical complications 
- Cardiac dysfunction (arrhythmias, myocardial infarction)
- Deep vein thrombosis and pulmonary embolism
- Urinary tract infections
- Bleeding (e.g., gastrointestinal bleeding)
Neurologic complications 
- Cushing triad) (
- SIADH) (
- Persistent neurologic deficits (hemiparesis, aphasia) and disability 
- Central poststroke pain 
- Neuropathic pain
- Hemorrhagic transformation
- Hemorrhagic stroke
We list the most important complications. The selection is not exhaustive.