Transient Ischemic Attack (TIA)

Definition/Etiology:

• Prior definition of TIA is outdated (resolution of symptoms in <24 hours).
• Ischemic CVA = infarction of central nervous tissue
• TIA = transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction

Framingham Heart Study:

• 45-54 yo, 0.22 per 1000 person-yrs
• 85-94 yo, 4.88 per 1000 person-yrs

Pathophysiology:

Neurologic tissue ischemia is caused by interruption of blood flow by:

• Thromboembolism
• Septic embolism
• Plaque embolism

Clinical Presentation:

Disabling signs/symptoms

• NIHSS > 5
• Complete hemianopsia
• Severe aphasia
• Visual or sensory loss
• Any weakness against gravity
• Inability to walk
• Any remaining deficit that is concerning

Differential diagnoses:

• Seizure
• Migraine aura
• Syncope
• Transient global amnesia
• Multiple sclerosis
• Peripheral vestibulopathy
• Hypoglycemia
• Myasthenia gravis
• Cranial/peripheral neuropathy
• Cerebral amyloid angiopathy
• Subdural hematoma
• Subarachnoid or intracerebral hemorrhage

Collaborative Management:

Fingerstick glucose stat

The old (<24 hour) definition was problematic.  If the patient has potentially disabling signs/symptoms, they should be treated without delay with mechanical thrombectomy or thrombolytics.

TIA is considered a neurologic emergency because of the likelihood of a CVA in the near future (days).

Consults:

• Neurology / Neurosurgery
• Cardiology PRN
• Vascular surgery

Tests:

• Echocardiography with bubble study
• TEE if suspected endocarditis or cardioversion is needed
• Holter or continuous monitoring vs loop recorder
• Carotid doppler ultrasound
• MRI/MRA vs CT/CTA

Procedures:

• Carotid endarterectomy
• PFO closure
• Watchman
• TEE cardioversion

Labs:

• Coags
• CBC
• CMP
• fasting lipids
• Hemoglobin A1c

Treatments: 

• DAPT vs full anticoagulation
• Ticagrelor (Brilinta) can cause dyspnea; watch for that
• Statins
• Antihypertensives PRN

Evaluation | Patient Monitoring | Education:

• Cardiac monitoring.  Look for Afib.
• Frequent neuro checks and NIBP.
• Educate re: s/s GI bleed if starting DAPT or anticoagulation.
• Educate re: adverse reactions to new antihypertensives and statins.

Linchpins: (Key Points)

• TIA is tissue ischemia. CVA is tissue infarct.
• Blood glucose stat on arrival.
• TIA should be treated with urgency just like a CVA.
• What caused the embolism?