Magnetic resonance imaging (MRI) showing an abnormally bright signal in the tongue is common among patients with late-onset Pompe disease, a study has found.
This particular imaging feature may hold diagnostic potential as it seems to be specific to Pompe disease patients with muscle weakness, not being detected in patients with other neuromuscular diseases such as amyotrophic lateral sclerosis (ALS), progressive lateral sclerosis (PLS), or myotonic dystrophy type 1 (MD1).
This finding was reported in the study, “Bright tongue sign in patients with late-onset Pompe disease,” published in the Journal of Neurology.
Brain MRIs are commonly used to help in the diagnosis of several neurological symptoms and disorders.
The tongue is visible in sided brain MRI, and its appearance in scans may give useful clues to a diagnosis. But tongue abnormalities are often missed or ignored by neurologists and radiologists when assessing brain MRIs.
Researchers at Oregon Health and Science University first noted an abnormally bright MRI signal in the tongues of two patients who were ultimately diagnosed with late-onset Pompe disease.
These patients were first subjected to a brain MRI scan because of symptoms of weakness. However, at first glance, the abnormally bright MRI signals in the tongue were dismissed. “Paying attention to these tongue abnormalities may have led to the correct diagnosis earlier,” the researchers said.
To further explore the diagnostic potential of these MRI signals, OHSU reviewed brain MRI imaging data collected from patients with muscle weakness due to various disorders who were followed at their institutions.
Abnormalities of the tongue were detected in 11 patients, but in only one of the cases were these abnormalities included in the radiology report. Bright tongue MRI sign was seen in four of the six (67%) patients with late-onset Pompe disease and in only four of the 28 (14%) patients with other neuromuscular disorders.
Tongue atrophy was detectable in half of Pompe patients and in six (21%) other patients.
Overall, these findings show that tongue abnormalities on brain MRIs are more common in late-onset Pompe disease compared to other neuromuscular disorders.
“Particular attention to the tongue when reviewing brain MRIs may be an important clue for diagnosis of a patient’s muscle weakness,” researchers said. In addition, the bright tongue signal may help correctly diagnose Pompe patients, “especially when patients are admitted to the ICU for respiratory failure of unclear origin.”
Despite the diagnostic potential of these findings, the team stressed that they do not suggest that patients with neuromuscular disorders should routinely undergo brain MRIs.
A larger study is still warranted to have better insights on the sensitivity and specificity of tongue abnormalities among patients with late-onset Pompe disease.