Effect of Dalfampridine (4-AP) on Genioglossus Muscle Activity in Healthy Adults (APIGLOSS)

The Effect of Dalfampridine (4-aminopyridine) on Genioglossus Muscle Activity During Wakefulness and Sleep in Healthy Control Subjects

In this protocol the investigators will test the effect of dalfampridine (a potassium channel blocker) on genioglossus muscle activity (EMG GG) during wakefulness and sleep in healthy control subjects.

Two overnight sleep studies, a placebo night and a drug night, will be performed approximately one week apart in random order. The placebo or drug will be administered 3 hours before lights out. At least 10 minutes of quiet wakefulness will be recorded to quantify the subject's awake EMG GG activity before the administration of placebo/dalfampridine. EMG GG activity will be measured again 10 mins before lights off and during stable NREM and REM sleep (free of arousals and other artifacts). During the second part of the night, the subjects will be connected to a modified continuous positive airway pressure (CPAP) machine (Pcrit3000, Respironics) which can provide a wide range of pressures between 20 and -20 cmH2O in order to modify upper airway pressure and measure change in EMG GG as a function of epiglottic pressure (muscle responsiveness).

Genioglossus Activity During Sleep Expressed as %Wakefulness Value (Before Drug/Placebo Administration).

The EMG GG was quantified in arbitrary units derived from signal processing of the raw signal and as a percentage of wakefulness (%wake) for between-nights comparison of baseline sleep EMG GG activity. EMG GG analysis was performed on a breath-by-breath basis to identify a maximum value and a minimum value during inspiration and expiration, respectively (EMG GG peak and tonic). The difference between peak and tonic values was used to estimate respiratory related phasic activity. Wakefulness EMG GG values were obtained from a minimum of 10 epochs (30 s each) with the subject lying in the lateral position. Criteria for breath selection during wakefulness were (1) stable breathing (constant epiglottic pressure swings) and (2) absence of movement artifacts (i.e., swallowing, speech, yawns).

Effect of dalfampridine on genioglossus muscle responsiveness to increased epiglottic pressure swings during sleep in healthy controls during NREM sleep. The variation of EMG GG is expressed here as % of maximal activation.

Inclusion Criteria: Healthy control subjects Exclusion Criteria: Cardiovascular disease other than well controlled hypertension History of seizures

Taranto-Montemurro L, Sands SA, Azarbarzin A, Marques M, de Melo CM, Edwards BA, Eckert DJ, Messineo L, White DP, Wellman A. Effect of 4-Aminopyridine on Genioglossus Muscle Activity during Sleep in Healthy Adults. Ann Am Thorac Soc. 2017 Jul;14(7):1177-1183. doi: 10.1513/AnnalsATS.201701-006OC.