Fig. 2

Representative neuroimaging in HPDL. Brain MRI findings in five HPDL patients (rows A–E). As indicated using roman numerals: T1-weighted mid-sagittal images (I), coronal T2-weighted images at the level of the medulla passing through the olivary nuclei (II) and cerebellar hemispheres (III), axial T2-FLAIR (IV) and T2-weighted (V) images at the level of the bulb. Patient F-H-ID10 (row D) is already reported elsewhere.43 Patients F-A-ID1 (row E) and F-A-ID2 (row B) did not show significant MRI alterations (only a slightly dysmorphic posterior portion of the corpus callosum in F-A-ID1, row E, see yellow arrowhead). Patient F-D-ID5 (row C) had very mild cerebellar atrophy with slight ventriculomegaly and moderate global cerebral atrophy. Patient F-C-ID4 (row A) showed a hypoplastic corpus callosum (yellow arrowhead: column I) and global cerebral atrophy. Patients F-C-ID4 and F-H-ID10 had cerebellar atrophy, T2 hyperintensities in the medulla oblongata (blue arrow: columns II, IV and V, rows A and D), middle cerebellar peduncle atrophy with T2 hyperintensity in the sub-dentate white matter (orange arrow: column III, rows A and D), and reduction of the cerebellar white matter volume and ventriculomegaly