Visualization of Parkinsonian Tongue Tremor on Ultrasonography

A 72-year-old man presented with a 1-year history of throat discomfort and involuntary tongue trembling, which was notably worse at rest with his mouth closed and was partially relieved by speaking. Neurological findings revealed mild parkinsonism, and brain magnetic resonance imaging and dopamine transporter single-photon emission computerized tomography were consistent with Parkinson disease (PD). He was diagnosed with clinically established PD according to the Movement Disorder Society criteria. An 8.0-MHz linear transducer was placed in the transverse plane of the upper anterior neck and directed to the lingual muscle. The B-mode image showed continuous rhythmic lingual muscle movement at rest with the mouth closed. The M-mode image identified the frequency of this movement for 5 Hz. These findings corresponded with a parkinsonian resting tremor. On tongue protrusion and teeth clenching, the tongue tremor was interrupted, and it restarted at the same frequency with a latency of 3 to 4 seconds. This supports a diagnosis of a parkinsonian reemergent tremor. The tongue tremor was paused during vocalization. To our knowledge, this is the first report on the ultrasonographic visualization of resting and reemergent parkinsonian tongue tremors. Ultrasonography is a viable diagnostic tool for patients presenting with involuntary tongue movements. Click the Related Article link for full details.