Marieke van Rosmalen

Chapter 5 76 ABSTRACT Objective: Chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) are caused by inflammatory changes of peripheral nerves. It is unknown if the intraspinal roots are also affected. This MRI study systematically visualized intraspinal nerve roots, i.e. the ventral and dorsal roots, in patients with CIDP, MMN, motor neuron disease (MND) and healthy controls. Methods: We performed a cross-sectional study in 40 patients with CIDP, 27 with MMN, 34 with MND and 5 healthy controls. All patients underwent an MRI scan of the cervical intraspinal roots. We systematically measured intraspinal nerve root sizes bilaterally in the transversal plane at C5, C6 and C7 level. We calculated mean nerve root sizes and compared them between study groups and between different clinical phenotypes using a univariate general linear model. Results: Cervical intraspinal nerve root size was larger in patients with CIDP, MMN and MND compared to healthy controls ( p < 0.001 – 0.003). Patients with a motor phenotype had thicker ventral roots compared to patients with a sensorimotor phenotype ( p = 0.018) and with MND ( p = 0.002), while patients with a sensory phenotype had thicker dorsal roots compared to patients with a sensorimotor phenotype ( p = 0.001) and with MND ( p = 0.006). Conclusion: We here show changes in the morphology of intraspinal nerve roots in patients with chronic inflammatory neuropathies, compatible with their clinical phenotype.