The BDNF polymorphism Val66Met may be predictive of swallowing improvement post pharyngeal electrical stimulation in dysphagic stroke patients.

BACKGROUND: The aim of this study was to explore the effect of brain-derived neurotrophic factor (BDNF) polymorphism rs6265 (Val66Met) in both "natural" and treatment induced recovery of swallowing after dysphagic stroke. METHODS: Sixteen dysphagic stroke patients that completed a single-blind randomized sham controlled trial of pharyngeal electrical stimulation (PES) within 6 weeks of their stroke (N=38), were genotyped for the BDNF SNP Val66Met (rs6265) from saliva samples. These patients received active or sham PES according to randomized allocation. PES was delivered at a set frequency (5 Hz), intensity (75% of maximal tolerated), and duration (10 minutes) once a day for three consecutive days. Clinical measurements were taken from patients at baseline, 2 weeks and 3 months post entering the study. Changes in swallowing ability based on the dysphagia severity rating scale (DSRS) were compared between active and sham groups and associated with BDNF SNP status. KEY RESULTS: In the active stimulation group, patients with the Met BDNF allele demonstrated significantly greater improvements in DSRS at 3 months compared to patients homozygous for the Val allele (P=.009). By comparison, there were no significant associations at the 2 week stage in either the active or sham group, or at 3 month in the sham group. Functional scores including the Barthel Index and modified Rankin scale were also unaffected by BDNF status. CONCLUSIONS & INFERENCES: Our findings suggest an association between BDNF and stimulation induced swallowing recovery. Further work will be required to validate these observations and demonstrate clinical utility in patients.

Integrated low-intensity biofeedback therapy in fecal incontinence: evidence that "good" in-home anal sphincter exercise practice makes perfect.

BACKGROUND: Biofeedback therapy (BFT) is an established treatment for fecal incontinence (FI), with access often being restricted to tertiary centers due to resources and the perceived requirement for high-intensity regimes. However, the optimal regime remains unknown. We evaluated outcomes from our low-intensity integrated BFT program in a secondary care center. METHODS: Outcomes of our BFT service for FI were evaluated retrospectively. Response was defined by ≥50% improvement in FI frequency from baseline or complete continence. Responders were compared to non-responders for factors including symptoms, manometry data, sphincter exercise technique and duration of practice, and the number and frequency of sessions. Where patients dropped out, outcomes and the reason for dropout were obtained retrospectively. KEY RESULTS: Fecal incontinence patients (n=205, median 62 years, 72% female) attended a median (IQR) 3 (2) BFT sessions with 55 (36) days between visits. Overall, 146/205 (71%) responded with 97/205 (47%) achieving continence. Fecal incontinence frequency improved dramatically in completed cases (P=0.000). While non-response was associated with males (P=0.03) and dropout (P=0.000), "good" anal sphincter exercise technique (P=0.008) and longer in-home practice (P=0.007) and more sessions (P=0.04) were associated with response. Dropout rate was 80/205 (39%), with the reason for dropout being obtained in 80%. CONCLUSIONS & INFERENCES: Despite low-intensity BFT, comparable outcomes to data from tertiary centers were achieved. Our data emphasize the importance of technique and in-home practice of anal sphincter exercises. Customizing BFT intensity based on predictive factors and encouraging in-home practice may optimize outcomes, reduce dropout rates, and rationalize resources.