Co-occurrence of Dystonic and Dyskinetic Tongue Movements with Oral Apraxia in Post-regression Dysphagia in Classical Rett Syndrome Years of Life 1 Through 5

We do not know the natural history of dysphagia in classical Rett syndrome (RTT) by stage or age. This study investigated swallowing physiology in 23 females ages 1:7 to 5:8 (years, months) with classical Rett syndrome to determine common and distinguishing features of dysphagia in post-regression early Pseudostationary Stage III. In-depth analysis of videofluoroscopic swallowing studies (VFSS) found dysmotility of oral stage events across subjects implicating oral apraxia. Impaired motility was further compromised by recurrent dystonic and dyskinetic movements that co-occurred with oral apraxia during oral ingestion in 78 % (n = 18) of the subjects with RTT. Of this group, 44 % displayed rocking and/or rolling lingual pattern, 56 % had recurrent oral tongue retroflexions, and/or elevated posturing of the tongue tip, and, 72 % displayed multi-wave oropharyngeal transfer pattern. The proportion of subjects whose swallowing motility was disrupted by aberrant involuntary tongue movements did not differ significantly between bolus types (liquid, puree, and solid) trialed. Liquid ingestion was significantly more efficient in subjects using bottles with nipples than their counterparts who used spouted or straw cups. Dystonic and dyskinetic tongue movements disrupted liquid ingestion in subjects using cups with spouts or straws significantly more than those using bottles. Analysis of food ingestion revealed that significantly more subjects were able to orally form, transport, and transfer a puree bolus into the pharynx than they were a solid bolus. A significantly larger number of subjects aspirated and penetrated liquid than they did puree or solid. No significant relationship was found between subjects with airway contamination and those with dystonic and dyskinetic tongue movements. Subjects’ rocking and rolling lingual patterns were consistent with those evidenced in adults with Parkinson’s disease. Subjects’ tongue retroflexions were classified as provisionally unique to RTT. VFSS pre-planning, fluoroscopic procedures, and therapeutic strategies specific to this specialty population were derived.