Question
What is the speech implication of uvula asymmetry?
Answer
Actually, I suspect the real question is, "What is the implication of uvula asymmetry?" There are actually a two layers to this response. The first layer follows the assumption that the uvula really is asymmetric. Of course, it is not clear if this means that the uvula itself is asymmetric, or that it is off-center from the midline of the palate, or that it is elevating asymmetrically on an oral examination. If the issue is one of structural asymmetry, this is consistent with a number of known multiple anomaly syndromes where asymmetry of the structures of the head and neck are common. These would include (but not be limited to):
- Oculo-auriculo-vertebral dysplasia (often referred to as OAVS or as hemifacial microsomia)
- Wildervanck syndrome
- Townes-Brocks syndrome
- Velo-cardio-facial syndrome (VCFS)
- Sturge-Weber syndrome
- CHARGE syndrome
- Hemihypertrophy
- Hemifacial hyperplasia
- MURCS association
- VATER and VACTERL associations
- Arthrogryposis multiplex congenita
- Neurofibromatosis, type I (NF1)
- Proteus syndrome
Asymmetry of this type could be a primary gene effect, or as in some of the syndromes above, secondary to a tissue dysplasia or abnormal vascular supply. Along with the structural asymmetry, there may be functional asymmetry of velar motion resulting in an asymmetric velopharyngeal insufficiency, something that has been documented in OAVS, VCFS, and NF1. If the velum is seen to elevate asymmetrically on phonation of "ah" with the mouth open, this means very little. Observations of palatal motion with the mouth open, a flashlight and tongue blade distorts the motion of the velum, and there is no way of knowing if the observed motion in this unnatural state of phonation actually represents what happens during normal speech. This introduces the second layer of the answer....peroral examination of velar motion is essentially useless. Oral exam is great for structure, terrible for function. It is therefore possible that observed motion of the velum with the mouth wide open represents an artifact of the examination, not the actual movement during speech. In any even, because consonants can not be phonated on an oral examination and isolated vowels are often nasalized, this information does not reflect actual performance. It is therefore not valid. If asymmetry is suspected, nasopharyngoscopy or multi-view videofluoroscopy in at least lateral and frontal views should be performed. If the asymmetry of structure or function is clearly asymmetric, referral to a clinical geneticist may be indicated depending on the patient's history and physical presentation.
Robert J. Shprintzen, Ph.D.
Director, Communication Disorder Unit
Director, Center for the Diagnosis, Treatment, and Study of Velo-Cardio-Facial Syndrome
Director, Center for Genetic Communicative Disorders
Professor of Otolaryngology
Professor of Pediatrics
Upstate Medical University
Syracuse, NY, USA
