Transient ischemic attack

Definition

"Transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia without infarction.” Stroke 2009;40[6]:2276

Background

1. Ischemic

• Thrombosis
• Vasculitis
• Dissection

2. Embolic

• Cardiac
• Carotids

3. Vasospasm

4. Hypotension (watershed)

DDx

• Hypoglycemia
• Infectious endocarditis
• Complex migraines
• Peripheral cranial nerve lesions
• Seizure

Work-Up

• Head CT
• Labs
  • CBC (thrombocytosis)
  • Chemistry (hyponatremia)
  • Coags
• ECG (a-fib)
• CXR
• ?MRI/MRA or ?Neuro labs (ESR?, lipids?)

Treatment

• Head of bed lowered
• Permissive hypertension
• NS 500cc bolus, then 150cc/hr (non-CHF/fluid overloaded)
• ASA
• Heparin if cardiac embolic source/a-fib (usually different vascular territories)

Disposition

AHA/ASA guidelines: Reasonable to hospitalize patients with TIA who present w/in 72 hr of symptom onset and meet any of the following criteria:

1. ABCD2 score of ≥ 3

2. ABCD2 score of 0-2 and uncertainty that the diagnostic workup can be completed within two days as an outpatient

3. ABCD2 score of 0-2 and other evidence that the event was caused by focal ischemia

ABCD2 SCORE

Age > 60 (1 pt)
Blood pressure (SBP >140 OR diastolic >90) (1 pt)
Clinical Features
* unilateral weakness (2 pt)
* isolated speech disturbance (1 pt)
Duration of symptoms
* >60 min (2 pt)
* 10-59 min (1 pt)
Diabetes (1 pt)

• None with score < 3 had CVA within one week in study

National Stroke Association reccomends hospitalization be considered for pts with first TIA w/in past 24-48 hours, and is generally recommended for pts with the following conditions:

• Crescendo TIA
• Duration of symptoms > 1hr
• Symptomatic carotid stenosis > 50%
• Known cardiac source of embolus
• Known hypercoaguable state
• High risk of early stroke after TIA

Literature:

Johnston, SC et al. JAMA. Dec 13, 2000.

   To determine which pts need to be admitted vs rapid outpatient evaluation.

   10% of pts with TIA developed CVA within 90 days. 

   50% (5%) within 2 days.

Kaiser Study

   Greater risk of CVA (admit any)

1. Age >60

2. DM

3. Duration >10min

4. Motor weakness

5. Speech impairment (dysarthria/ aphasia)

Numbness is low risk: outpt f/u with Neuro

(also, at increased risk of CVA if >4 TIA spells within last 2 wks, or escalating / crescendo TIA)

Transient monocular blindness (amaurosis fugax) more benign.

in Mayo Clinic Proceedings, Nov 1994. 33% of pts with TIA will have CVA within 5 yrs.

   high risk... inpt w/u

   low risk... expedited outpt w/u

   ECG for a-fib

   Echocardiogram, TEE most sensitive.  prosthetic valves... DCM... mural thrombosis, SBE, post-MI.

   Carotid duplex, if +, cerebral angiogram, then CEA.

   ----ASA

   ----Heparin if cardiac embolic source/a-fib.  usually different vascular territories.

   ----if ASA intolerant or ASA failure, then Ticlopidine.  consider Coumadin.

   or,         Plavix alone.  

TIA ADMIT (nmlly neg sy; <1hr)

1) any Johnson criteria

2) <1 wk from onset

Source

DONALDSON (Smith, Lampe, NEJM '07, Pani)