Migraine duration and left-right differences in periventricular DTI-ALPS: a case-control diffusion MRI study

Background Diffusion tensor image analysis along the perivascular space (DTI-ALPS) provides a local diffusion index in periventricular white matter. We examined adjusted bilateral patient-control differences and whether reported migraine duration related differently to left and right ALPS. Methods The study included 25 healthy controls and 64 participants with migraine. Generalized estimating equations (GEE) accounted for paired left and right measurements. The patient model included disease duration, age, baseline monthly migraine days (MMD), sex and body mass index, with each allowed a side-specific association. Sensitivity analyses evaluated tensor reorientation and alternative periventricular regions of interest (ROIs). Results There was no evidence of an average bilateral patient-control difference. The duration-by-side interaction was positive ( β =0.0053 per year, 95% confidence interval 0.0022 to 0.0084; P < 0.001). The left-sided duration slope was negative; the right-sided slope was near zero and was not statistically significant. The interaction remained positive with an external literature-derived local ROI definition but was not reproduced by broader atlas sampling. Conclusions Longer reported migraine duration was associated with a less leftward ALPS profile in sampled periventricular white matter, with no evidence of an average bilateral patient-control shift. The spatial sensitivity results support a local interpretation of this cross-sectional association.