Korean language specific dysarthria associated with idiopathic peripheral facial palsy

To investigate the patterns of dysarthria in Korean patients with idiopathic peripheral facial palsy. Seventy-eight patients diagnosed with idiopathic peripheral facial palsy within the onset of symptom to 7 day time frame were prospectively enrolled. The initial symptom of facial palsy was examined by the House-Brackmann scale. All patients were tested by Urimal-Test of Articulation and Phonology-2 (U-TAP-2), which is specialized for the evaluation of dysarthria in Korean language - Hangeul - when the patients first visited and were followed up at 4 weeks after the onset, respectively. The facial electromyography was performed after 7 days, since the presentation of the first symptom. Electric stimulation therapy and simple facial exercise education were performed in all patients as routine treatments for facial palsy with or without dysarthria. The patterns of dysarthria were analyzed by initial and follow-up U-TAP-2 results, respectively. Among 78 patients, 50 patients (64.1%) had dysarthria in the first assessment. The 6 consonants and 3 vowels were errored in U-TAP-2 test. The bilabial consonants “ㅃ”[p] or “ㅍ” [p(h)] were substituted with labiodental consonant [f], and palate-alveolar consonants were replaced by alveolar consonants - “ㅊ”[t͡ɕ(h)] to “ㅌ”[t(h)]. Bilabial consonant “ㅁ”[m] was replaced by velar nasal consonant “ㅇ”[ŋ]. Liquid consonant was altered to nasal sound. For example, “ㄹ”[r] is replace by “ㄴ”[n]. The velar consonant “ㄲ”[k] was pronounced as “ㅋ” [k(h)]. The diphthong vowels “ㅟ”[ɥi], “ㅚ”[ø], or “ㅘ”[wa] were pronounced as monothong “ㅣ” [i], “ㅐ”[ε], or “ㅏ”[a], and “못”[mot] is slowly pronounced. After 4 weeks, 14 patients still showed pronunciation errors in 5 consonants and 3 vowels. The most common error was substitution. Among 78 patients with idiopathic peripheral facial palsy, 50 patients had dysarthria and 14 out of 50 patients with dysarthria lasted more than 4 weeks. Five consonants (“ㅁ”, “ㅊ”, “ㅍ”, “ㄹ”, “ㄲ”) and 3 vowels (“ㅘ”, “ㅗ”, “ㅟ or ㅚ”) were still mispronounced after 4 weeks, and most common error was substitution. Therefore, speech evaluation and speech therapy specialized for errors in high frequency of consonants and vowels are needed in patients with idiopathic peripheral facial palsy, in Korea.