SPG11 and cerebellar ataxia: Of note, the SPG7 phenotype may vary between pure spastic paraplegia and a predominantly spastic-ataxic phenotype with cerebellar atrophy on brain MRI.65Less frequently, SPG11 can present with ataxia, but usually, patients also have mild intellectual disability or progressive cognitive decline and peripheral neuropathy, with brain MRI typically disclosing tinning of the corpus callosum.66