Mitochondrial membrane protein associated neurodegeneration

Mitochondrial membrane protein-associated neurodegeneration (MPAN) is an autosomal recessive form of neurodegeneration with brain iron accumulation (NBIA).

Clinical presentation

Lower limb spasticity, dysarthria, dysphagia, dystonia, neuropsychiatric symptoms, optic atrophy, Parkinsonism, and cognitive decline .

Pathology

MPAN is caused by mutations in C19orf12 gene, leading to iron accumulation in the globus pallidus and substantia nigra, gliosis, and neuronal loss. Cortical and cerebellar atrophy may be seen .

Radiographic features

MRI

Iron accumulation (hypointense signal on T2* and GRE) in the globus pallidus and substantia nigra .

A distinctive finding is a linear T2 hyperintensity in the medial medullary lamina between globus pallidus interna and externa, with absence of eye of the tiger sign (rarefaction of the central globus pallidus) .