The absence of infratentorial lesions, particularly when combined with corpus callosum (CC) involvement, can aid in the differential diagnosis of Fabry disease (FD) vs multiple sclerosis (MS), according to the results of a retrospective study conducted in Italy that evaluated magnetic resonance imaging (MRI) scans from patients with either of  the 2 diseases. The study findings were published in Brain and Behavior

The investigators sought to examine the incidence of infratentorial lesions in patients with FD in an effort to explore the diagnostic accuracy of this sign alone and in combination with CC involvement. They studied MRI scans from 144 patients with FD and 136 patients with MS. All participants with FD received a genetically confirmed diagnosis, whereas participants with MS encompassed all clinical phenotypes of the disease and met the 2010 revised McDonald criteria.

In all participants, white matter lesions were retrospectively assessed on FLAIR images. Infratentorial involvement was evaluated with respect to the whole cerebellum, along with the part of the brainstem between the occipital foramen and the upper edge of the red nucleus. The presence of callosal lesions was also investigated via assessment of the portion of the CC included between the 2 external walls of the lateral ventricles.

Infratentorial involvement was detected in 87.5% (119 of 136) of patients with MS and in only 11.8% (17 of 144) of patients with FD. Moreover, CC lesions were observed in 89.0% (121 of 136) of participants with MS and in only 5.6% (8 of 144) of those with FD.

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According to an analysis of diagnostic odds ratios (ORs), the best overall performance was attained when both infratentorial and CC involvement were considered. The simultaneous presence of both CC and infratentorial lesions corresponded to an OR of 163.3, which was significantly higher than the sole assessment of the CC (OR 137.1; P <.001) or of the infratentorial region (OR 52.3; P < .001), as well as the positivity of  at least one of the 2 areas (OR, 93.7; P <.001).

The investigators concluded that the absence of infratentorial lesions, particularly when combined with other typical imaging features, can aid in distinguishing between FD and MS. Additional studies are warranted to examine a larger number of patients with similar MRI sequences, possibly on scanners of the same field intensity.

Reference

Ugga L, Cocozza S, Pontillo G, et al. Absence of infratentorial lesions in Fabry disease contributes to differential diagnosis with multiple sclerosis. Brain Behav. 2018;8(11):e01121.