Control/Tracking Number: 05-A-1250-CRF

Activity: Abstracts
Current Date/Time: 6/9/2005 3:17:00 PM

Migrane Induction by Brain Micro-Embolization During Contrast Transcranial Doppler Evaluation of Right-to-Left Shunt

Sherman G Sorensen¹, Deborah L Davis², Laurie Raleigh², Heather Aguilar³, Peter J Casterella¹, Brianna S Ronnow³, Ali K Choucair³, Donald L Lappé¹, Heidi Thomas³, Joseph B Muhlestein^3
1Utah Heart Clinic and LDS Hospital Cardiology, Salt Lake City, UT;²Utah Heart Clinic, Salt Lake City, UT;²LDS Hospital Cardiology, Salt Lake City, UT

BACKGROUND: Brain micro-embolization (mEMB) due to right-to-left shunt (RLS) has been described with contrast echocardiography, brain imaging (MRI) of divers with decompression illness, and patent foramen ovale (PFO) closure procedures (during catheter crossing of the PFO). RLS occurs in 50% of migrane (MHA) patients with several reports describing migrane improvement or even resolution with PFO closure and resolution of RLS.

METHODS: Of 490 patients (pts) undergoing percutaneous PFO closure for recurrent stroke, 176 (36%) reported active MHA before closure with 49 (28%) having aura (A). Pre- and 90 day post-procedural power M-mode transcranial Doppler (TCD) with rest (R) and calibrated valsalva (V) agitated saline contrast intra-venous injections were performed (N=148). Cerebral mEMB events were quantified by automatic embolic detection program (scale of 1-5). Anecdotal reports or severe MHA symptoms (MHA, A, visual loss, vertigo, [MHA-SX]) induced by TCD prompted consideration of brain mEMB as a trigger for MHA. A separate group of 225 consecutive patients referred for diagnostic TCD were evaluated by questionnaire as to the onset of MHA-SX with TCD. Indications for diagnostic TCD: cerebrovascular accident (CVA)=22%, transient ischemic attack (TIA)=30%, MHA=49%, and abnormal MRI=69%.

RESULTS: Responses to PFO closure pre- vs 90-day post procedural of active MHA: 176 vs 23 pts (p=0.001), TCD-R: 2.74 +/- 1.02 vs. 0.52 +/- 1.02 (p=0.0001), and TCD-V: 4.73 +/- 0.73 vs. 1.86 +/- 1.71 (p=0.0001). MHA-SX with TCD occurred in 23% of pts with 31% of the MHA-SX and 50% of the MHA pts having a grade 5 shunt with MHA-SX more likely to have a higher shunt (p=0.003). Patients with history of MHA=131(58%), 49.6% had a grade 5 TCD-V. Although, MHA-SX were induced in pts without any history of MHA in daily life, MHA pts were 4 times as likely to have MHA-SX with TCD (p=0.01) than non-MHA pts.

CONCLUSIONS: We postulate that: 1) Brain micro-embolization during contrast TCD may trigger migrane symptoms in patients with RLS, 2) Brain sensitization in migrane sufferers results in heightened response to mEMB, and 3) Spontaneous mEMB during daily life in patients with large RLS may trigger MHA or other neurologic symptoms.

Author Disclosure Block: S.G. Sorensen, None.