Middle Cerebellar Peduncles T2-Hyperintense Signal in Fazio–Londe Syndrome

A 14-month-old girl presented with progressive bilateral ptosis, dysphonia, and dysphagia. At 8 months, she developed generalized weakness requiring mechanical ventilation. A few weeks later, a percutaneous gastrostomy tube was placed due to marked worsening of dysphagia. Extensive laboratory blood and cerebrospinal fluid investigations, fundus examination, hearing test, and muscle biopsy were unrevealing. Brain magnetic resonance imaging (MRI) at 9 months showed bilateral, symmetric T2-hyperintense signal of the middle cerebellar peduncles (MCP; [Fig. 1]). Whole exome sequencing revealed homozygous mutations in SLC52A3, suggesting Fazio–Londe syndrome (FLS).[1] A therapy with high doses of riboflavin was started.

Fig. 1 A 9-month-old girl with Fazio–Londe syndrome. (A) Axial T2-weighted and (B) fluid attenuation inversion recovery images show bilateral, symmetric hyperintense signal within the middle cerebellar peduncles (arrows).

FLS and Brown–Vialetto–Van Laere syndrome[2] are rare, treatable motor neuron disorder with childhood onset due to riboflavin transporter deficiency.[1] [2] [3] The presence of sensorineural deafness favors the diagnosis of Brown–Vialetto–Van Laere syndrome, although both diseases are most likely allelic conditions that present along a phenotypic spectrum. Brain MRI may show normal findings, T2-hyperintense signal of brainstem nuclei, atrophy of the brainstem and cerebellum, or T2-hyperintense signal abnormalities of the MCP like in our patient. In addition to peroxisomal and mitochondrial disorders and toxic leukoencephalopathies, FLS should be considered in the differential of diseases presenting with bilateral, symmetric T2 hyperintense signal within in the MCP.[4]

• References

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• 2 Johnson JO, Gibbs JR, Megarbane A. , et al. Exome sequencing reveals riboflavin transporter mutations as a cause of motor neuron disease. Brain 2012; 135 (Pt 9): 2875-2882
• 3 Timmerman V, De Jonghe P. Promising riboflavin treatment for motor neuron disorder. Brain 2014; 137 (Pt 1): 2-3
• 4 Morales H, Tomsick T. Middle cerebellar peduncles: magnetic resonance imaging and pathophysiologic correlate. World J Radiol 2015; 7 (12) 438-447