[MRI findings of the tongue in neurodegenerative diseases with bulbar sign].

We examined the magnetic resonance image (MRI) of the tongue in cases of amyotrophic lateral sclerosis (ALS), bulbo-spinal muscular atrophy (SBMA) and Shy-Drager syndrome (SDS) with sleep apnea. ALS case with severe bulbar disorder showed atrophic, irregularly margin tongue with increased signal intensity in T1-weighted MRI. ALS with less severe bulbar disorder demonstrated mixed hyperintensity and normointensity areas in the tongue. ALS without lingual symptoms showed increased intensity of tongue which suggested subclinical involvement of lingual muscle. BSMA case also showed atrophic tongue with diffusely increased signal intensity. SDS case with sleep apnea was revealed to have round shaped tongue without increased signal intensity, but his tongue fell into the posterior oral cavity, indicating hypotonus of genioglossus muscle. We concluded that MRI of the tongue is useful to determine the bulbar symptoms due to lower neuron disorder or not.