Role of the nigrosome 1 absence as a biomarker in amyotrophic lateral sclerosis.

Introduction: The absence of nigrosome 1 on brain MRI and the hyperechogenicity of substantia nigra (SNh) by transcranial sonography are two useful biomarkers in the diagnosis of parkinsonisms. We aimed to evaluate the absence of nigrosome 1 in amyotrophic lateral sclerosis (ALS) and to address its meaning.

Methods: 136 ALS patients were recruited, including 16 progressive muscular atrophy (PMA) and 22 primary lateral sclerosis (PLS) patients.