Definition - The stroke may be considered to be crypto-
genic after standard evaluation when clinical
examination and brain imaging suggest a super-
ficial or large, deep cerebral infarct, but none
of the above routine vessel-imaging, cardiac, or
hematologic tests has revealed a probable cause.
- Patients with a small, deep infarct also may be
considered to have cryptogenic stroke if they are
younger than 50 years of age, have no standard
vascular risk factors, and have no white-matter
hyperintensities or prior small, deep infarcts.
Epidemiology and Main features of Cryptogenic Stroke - 10-40 % of strokes are cytoptogenic stroke; 120,000 to 180,000 patients each year in the United States.
- More than 200 etiology of strokes have been defined
- Age of patients influences the likelihood of various causes
- Better prognosis
- Diffusion sequences of MRI is more sensitive to small lesions and lesions in the brain stem and
cerebellum
- Imaging features that suggests etiology of stroke
- infarcts in multiple territories suggest emboli
from a proximal aortocardiac source;
- infarcts of
different ages in a single territory suggest emboli of arterial origin;
- infarcts along the borders
between brain artery territories suggest systemic
hypotension or multiple emboli; and
- a small deep infarct along with white-matter hyperintensities suggests intrinsic small-vessel disease
- USG neck and Transcranial USG are usually done only if MRA neck or CTA neck are contraindicated
- TEE identifies potentially salient abnormalities in approximately 50 to 75% of young
patients with otherwise cryptogenic stroke, including patent foramen ovale, atrial septal
aneurysm, endocarditis, aortic atherosclerosis,
regional myocardial-wall dysfunction, dilated left
atrium, and atrial appendage thrombi
- As compared with the
TOAST criteria, both the ASCOD and CCS systems identify fewer patients as having had cryptogenic stroke
Diagnosis and Work up for Cryptogenic Stroke
Advanced Evaluation for Cryptogenic Stroke
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