To investigate the evolution and clinical significance of vasoconstriction on magnetic resonance angiography (MRA) in patients with reversible cerebral vasoconstriction syndromes (RCVS).


Patients with RCVS were recruited and followed up with MRA examinations until normalization of vasoconstriction or for 6 months. The vasoconstriction severity of the major cerebral arterial segments (M1, M2, A1, A2, P1, P2, and basilar artery) was scored on a 5-point scale: 0 (0–<10%), 1 (10–<25%), 2 (25–<50%), 3 (50–<75%), and 4 (≥75%). Subjects with at least 1 segment with a vasoconstriction score ≥2 were eligible for the study. Initial mean scores of single or combined arterial segments were used to predict ischemic complications.


Seventy-seven patients with RCVS (8 men/69 women; average age 47.7 ± 11.6 years) finished the study with a total of 225 MRAs performed. The mean number of arterial segments involved was 5.3 ± 3.0 in the initial MRA. Vasoconstriction scores reached their maximum 16.3 ± 10.2 days after headache onset, close to the average timing of headache resolution (16.7 ± 8.6 days). Vasoconstriction evolved in a parallel trend among different arterial segments. Seven (9.1%) patients developed posterior reversible encephalopathy syndromes (PRES). Six (7.8%) patients had ischemic stroke. A logistic regression model demonstrated that the M1–P2 combined score was associated with highest risk of PRES (odds ratio [OR], 11.6, p = 0.005) and ischemic stroke (OR, 3.4; p = 0.026).


MRA evaluation in patients with RCVS is valid. Vasoconstriction was pervasive and outlasted headache resolution. Vasoconstrictions in M1 and P2 are important determinants for PRES and ischemic stroke. ANN NEUROL 2010;67:648–656