Original ArticleAn Ultrasound Investigation of Tongue Shape in Stroke Patients with Lingual Hemiparalysis

BackgroundStroke can cause hemilateral paresis of the tongue. The present study investigated the functional consequences of a lingual hemiparalysis on the symmetry and the grooving of the tongue in the coronal plane during the production of vowel-consonant-vowel sequences. The hypotheses were that, because of the lingual hemiparalysis, the stroke patients' tongue shapes would be (1) more asymmetrical and (2) less grooved than the tongues of the control speakers.MethodsThe participants in this prospective data collection were 9 stroke patients with lingual hemiparalysis and 6 control speakers. All participants produced vowel-consonant-vowel sequences with the vowels [a, i, and u] and the target consonants [k, t, ∫, s, and r]. The tongue shape in the coronal plane was traced and measured. The outcome measures were asymmetry and midlingual concavity. The participants and controls were compared using repeated measures analyses of variance with post hoc Scheffé tests.ResultsThere were no significant differences in asymmetry. There was significantly reduced midlingual concavity for the stroke patients (F[1, 13] = 8.78; P < .05). There was also a within-subjects effect for consonant (F[4, 50] = 14.26; P < .01). Post hoc testing with Scheffé tests indicated that the consonant [k] had significantly lower grooving than the other consonant sounds (P < .05).ConclusionsThe hemilateral paresis affected not the symmetry but the midlingual grooving. Residual ipsilateral innervation in the hemiparalyzed tongue may help patients compensate. More research is needed to assess the impact of the intrinsic deformation of the tongue on speech acceptability and intelligibility in patients with a lingual hemiparalysis.