The bright tongue sign is a radiological sign most commonly described in amyotrophic lateral sclerosis with bulbar involvement 1,2. However, this sign is not pathognomonic, and may be seen with other myopathies or neuropathies with tongue or bulbar involvement (e.g. Kennedy disease, Pompe disease) 3,4.
The bright tongue sign describes hyperintensity of the tongue on T1 weighted MRI, often best appreciated in sagittal views 1-4. It represents chronic denervation and resultant fatty replacement 1,2.