Table 2.

Summary of studies comparing the frequency of DVT among patients with cryptogenic vs. known-cause stroke.

References	Population % (n)	Work-up for DVT	DVT prevalence in Non-CS vs. CS, % (n)	Time between Index stroke and DVT workup
Cramer et al. (22)	Non-CS: 52% (n = 49) CS: 48% (n = 46, among them 61% with an PFO or ASD)	MRI Venogramm	Total patients 4% (2/49) vs. 20% (9/46); p = 0.025 Subgroup with PFO 0% (0/9) vs. 21% (6/28); p = 0.30	48.9 ± 16.1 h
Liberman et al. (23)	All Patients had PFO (n = 131) CS: 74.8% (n = 98) Non-CS: 25.2% (n = 33)	MRI Venogramm LE duplex ultrasound	9.1% (3/33) vs. 7.2% (7/98); p = 0.71	0–4 days

PFO, patent foramen ovale; CS, cryptogenic stroke; PE, pulmonary embolism; DVT, deep vein thrombosis; VTE, venous thromboembolism; MRV, magnetic resonance venography; N/A, not available.