Prognostic value of decreased tongue strength on survival time in patients with amyotrophic lateral sclerosis

Decreased tongue strength (TS) might herald bulbar involvement in patients with amyotrophic lateral sclerosis (ALS) well before dysarthria or dysphagia occur, and as such might be prognostic of short survival. The purpose of this study was to investigate the prognostic value of a decreased TS, in addition to other prognostic factors, such as site of onset, bulbar symptoms, bulbar signs, age, sex, maximum phonation time, time from symptoms to diagnosis, and gastrostomy, for survival time in patients with ALS. TS was measured in four directions in 111 patients who attended the diagnostic outpatient motor neuron clinic of our university hospital. Of these patients, 54 were diagnosed with ALS. TS was considered abnormal if the strength in minimally one direction was at least two standard deviations below the reference values obtained from comparable age category and sex-groups of healthy controls (n = 119). Twenty of the patients with ALS had a decreased TS. Multivariable analysis showed that, in addition to age, TS was an independent prognostic factor for survival time in patients with ALS