Drooling and Tongue Protrusion
- Given the negative implications for health, social interaction, and participation, behavioral procedures have been developed to reduce drooling and tongue protrusion.
- For drooling, five types of behavioral procedures have been shown to be effective: (a) instruction, prompting, and positive social reinforcement; (b) negative social reinforcement and other decelarative procedures; (c) cueing techniques; (d) microswitch-based techniques, and (e) self-management procedures.
- For tongue protrusion, there is some preliminary evidence for comparable behavioral procedures (except for microswitch-based techniques), although studies on behavioral treatment are very limited.
- The behavioral procedure of choice for drooling and tongue protrusion is dependent on personal factors (e.g., motor ability, learning ability, intrinsic motivation) and environmental factors (e.g., availability of staff, acceptability of devices). Guidelines are provided.
- For both drooling and tongue protrusion, behavioral procedures should be considered before other, more intrusive treatments like medication and surgery are implemented.
Drooling and tongue protrusion are challenging behaviors commonly observed in persons with developmental disabilities. Given their negative implications for health, and social interaction and participation, behavioral procedures have been developed to reduce these behaviors. In this chapter, we will present a selective review of studies on behavioral procedures for drooling and tongue protrusion and discuss their applicability in persons with developmental disabilities.
Drooling: Definition, Prevalence, and Cause
Blasco and Allaire (1992, p. 849) define drooling as “the unintentional loss of saliva and other contents from the mouth.” Drooling severity varies from incidental occurrence of saliva below the lower lip line to strings of dribble continuously falling from the mouth or chin. Drooling is a normal phenomenon up to the age of 18 months, but it persists in children with poor neuromuscular coordination, intellectual disability (ID), and/or children with no structural integrity of jaws, lips, or oral cavity. Drooling is reported in 10–37.5% of patients with cerebral palsy (CP; Ekedahl & Hallen, 1973; Van de Heyning, Marquet, & Creten, 1980). This percentage appears to be even higher among CP children attending special schools: 58% of 4- to 18-year-old children were reported to drool, with 33% (53/160) of the total school population drooling severely (Tahmassebi & Curzon, 2003).
Drooling is not caused by hypersalivation, except for children with dyskenetic CP (Erasmus et al., 2009). In other children with CP, persistent drooling is primarily due to oral motor dysfunction: inefficient (particularly in the oral phase) and/or infrequent swallowing and/or poor lip closure (Sochaniwskyj et al., 1986; Harris & Purdy, 1987; Hussein et al., 1998). In addition, Burgmayer and Jung (1983) state that saliva running down the lower lip or chin causes an aversive sensation in infants. In the normal development of swallowing, the young child learns to avoid this unpleasant sensation. If this aversive sensation does not occur in CP, swallowing as avoidance behavior does not develop spontaneously.
Drooling affects physical health and well-being negatively. Children suffer from chronically irritated, chapped, or macerated skin over the chin and peri-oral region leading to cheilitis in 67% of the cases (Wilson & Henderson, 1999). Sometimes there is a chronic loss of fluids and nutrients, and in case of posterior drooling (Jongerius et al., 2005), children with inadequate swallowing frequently aspirate their own saliva, which may cause recurrent pneumonia. In addition, drooling has an adverse effect on social and emotional functioning (Van der Burg et al., 2006).
Drooling: Description of Treatment Procedures
Behavioral treatment for drooling aims at increasing target behaviors such as swallowing, wiping, head control, mouth closure, nondrooling, and self-control. In this section we distinguish five types of treatment procedures: (a) instruction, prompting, and positive social reinforcement; (b) negative social reinforcement and other decelarative procedures; (c) cueing techniques; (d) microswitch-based techniques, and (e) self-management procedures.
Instruction, Prompting, and Positive Social Reinforcement
Instruction and prompting are both antecedent techniques preceding the target behavior. For example, the child is instructed to wipe the face whenever the chin is wet or is prompted to swallow if the trainer spots saliva on the child’s lip or before beginning to talk.
Positive social reinforcement is an example of a consequent technique. Following the performance of target behavior, a reinforcing stimulus such as a positive remark is given, occasionally paired with a token or an edible. In several studies, positive reinforcement for nondrooling behavior was given. This behavioral technique is called differential reinforcement of other (nonchallenging) behavior (DRO).
Typically, combinations of behavioral techniques are used. For instance, Garber (1971) successfully reduced drooling during articulatory therapy in a 14-year-old boy by prompting him to swallow before speaking. In addition, he was verbally praised for swallowing and rewarded with pennies for being dry during increasing time intervals. In a related study, Barton and Madsen (1980) prompted an 11-year-old boy who had severe ID to wipe his face contingent on drooling and praised him for both wiping and nondrooling for which he also received drinks. DRO was also implemented by Richman and Kozlowski (1977). After positive reinforcement of head control and imitative vocalization in a 9-year-old girl with severe ID, they found an improvement in these target behaviors in addition to a reduction in drooling.
Negative Social Reinforcement and Other Decelarative Procedures
Negative social reinforcement and other decelarative procedures are also consequent procedures. Contingent upon the occurrence of drooling, a negative stimulus such as a verbal warning or a time-out is given (Poling et al., 1978; Connis & Rusch, 1980; Burgmayer & Jung, 1983). Connis and Rusch (1980) report a significant decrease in drooling in a 22-year-old adult with moderate ID as a result of a treatment package consisting of reprimands for drooling, instructions to keep his mouth closed, and praise for being dry, which were all faded (i.e., gradual reduction of implementation of these techniques). Burgmayer and Jung (1983) used a brief period of withdrawal of attention (time-out) by the therapist contingent on drooling.
In some studies, a more intrusive decelerative procedure is implemented contingent upon drooling (Drabman et al., 1979; Trott & Maechtlen, 1986; Kay, Harchik, & Luiselli, 2006). Kay et al. (2006) trained a 17-year-old student with autism who attended a public high school. After preteaching sessions in which he was taught to respond to the instructions “Swallow” and “Wipe your mouth,” regular checks (increasing from 5 to 15 minutes) were made by the aid in the classroom, community vocational site, and cooking class throughout the school day. If the student’s face was dry, he was praised, and an edible treat was presented. If his face was wet, he was required to wipe his mouth and swallow three times successively; a procedure called “overcorrection.” Drabman et al. (1979) described two studies in which the most intrusive overcorrection procedure was used: contingent upon drooling, a verbal reprimand was given and the child was prompted to wipe his or her chin 50 times.
Several studies report on a specific prompting procedure by electronic cueing (Barton, Leigh, & Myrvang, 1977; Rapp & Bowers, 1979; Rapp, 1980; Jones, 1982; Burgmayer & Jung, 1983; Koheil et al., 1987; Lancioni et al., 1989; Lancioni, Brouwer, & Coninx, 1992, 1994). An electronic cueing device emits visual, auditory, or tactile cues (i.e., antecedent stimuli) to increase the frequency of swallowing or wiping the mouth and chin. Cueing frequency varies across studies from once every 15 seconds (Barton et al., 1977) to every 5 minutes (Burgmayer & Jung, 1983). In the first studies, the device was situated on a table, while in later studies, portable cueing devices were worn by participants.
In their extensive study of over 500 sessions per participant, Barton et al. (1977) trained two men (24 and 28 years; moderate and severe ID, respectively). Swallowing was verbally prompted and rewarded with tokens. The second participant also received a visual cue light every 15 seconds to pace swallowing. To elicit a wiping response, an auditory cue from a buzzer on the table was presented contingent upon the occurrence of drooling. Both electronic cues were gradually faded out. Rapp and Bowers (1979) described a portable cueing device (a so-called dribble box) that electronically prompted seven children with CP (aged 15–16 years; developmental age 4–8 years) to swallow after a 2- to 3-second auditory cue at fixed time intervals. After the stimulus–response chain (i.e., swallowing contingent on the cue) was established during an undemanding task, the children wore the device attached to their clothes throughout the day. While Rapp (1980) used a small box pinned to the child’s clothes, Burgmayer and Jung (1983) used a watch, which produced an auditory cue of about 30 dB at 5-minute intervals to elicit regular swallowing in an 8-year-old male with CP and severe ID.
Lancioni et al. (1992) evaluated different cueing procedures with “brief” versus “flexible” auditory cues in two participants who had moderate to severe ID (aged 27 and 20 years). Brief cues with a fixed duration (2.5 seconds) were given at fixed intervals (2 minutes). Flexible cues lasted until the target response occurred, after which a new interval started. Lancioni et al. (1992) concluded that flexible cues are particularly effective in producing a consistent response, while brief cues may be sufficient to ensure a response from some individuals, but not from all.
Cueing techniques for drooling have also been adapted for people who are deaf. Lancioni et al. (1989) trained two participants who were deaf (aged 11 and 16 years; the first had mild ID next to motor disabilities, the second had a learning disability without motor disabilities) through the use of tactile and visual cues, which lasted until the wiping response was performed. If the response was performed spontaneously, the cue was avoided. The portable cueing device consisted of an electronic circuitry which included a timer (placed at the participant’s belt), a vibrator (at the waist or connected with the ear mold of the hearing aid) or a light (at the inside of the frame of the participants’ eyeglasses), and a response sensor (a wireless transmitter on the wrist which, whenever in close proximity, activated a tiny receiver at the shoulder). The wiping response was registered and resulted in the interruption of cueing and/or resetting of the timer to a new interval.
Seven studies were carried out with the use of microswitch-based technologies for persons with severe/profound ID and multiple disabilities (Lancioni et al., 2008a,b, 2009a,b,c, 2011a,b). These studies were aimed at evaluating technological solutions that allowed both direct monitoring of specific participants’ responses appropriate to reduce the effects of drooling, and automatic delivery of positive stimulation (i.e., consequent stimuli) contingent on those responses. One form of technology used in those studies consisted of a pressure microswitch, an amplified MP3 for musical stimulation, and an electronic control system, all embedded in the napkin that the participant wore.
For example, Lancioni et al. (2009b) carried out a study with two participants. The technology used for the first participant (a boy of 12 years of age) relied on a napkin containing a pressure microswitch and a radio transmitter. Whenever the boy pressed the napkin against his chin/mouth to wipe out the saliva, the pressure microswitch was activated. This activation triggered the radio transmitter, which in turn put on an electronic control system and a screen with visual stimuli accompanied by various auditory inputs. The stimuli remained on for a period of 8 seconds. The sessions lasted 5 minutes. Data showed that the boy increased the frequencies of mouth-wiping responses from very low levels to about 16 and 20 during the two intervention phases, respectively. This response increase coincided with declines in the percentages of observation intervals with chin wetness. The second participant (a man of 32 years of age) relied on the use of an optic microswitch and a handkerchief. Wiping his mouth through the handkerchief activated the optic microswitch, which was fixed to his shirt at the basis of his neck. This activation triggered a radio transmitter and an electronic control system, which ensured 8–10 seconds of vibrotactile stimulation. This was produced by one of two devices fixed at the waist and on the legs of the man, respectively. Once the man had consolidated his responding, the stimulation conditions were changed to regulate (reduce) the frequency of his wiping response. The changes consisted of adding a growing appendix of low-impact stimuli (i.e., stimuli of reduced intensity and possibly reduced effect) to the 8–10 seconds of preferred vibration. The length of the appendix finally reached 16 seconds. Such an extension was considered a functional strategy to widen the inter-response interval, as the man was not expected to respond during the presence of stimulation. Reducing the overall response frequency was thought sufficient to control the effects of drooling, improve the man’s social appearance, and reduce risks of skin irritation. The session lasted 5 minutes, but two or three sessions could be carried out in succession. Data showed that the man had about 20 responses per session prior to the extension of the stimulation period and about 10 responses per session after the extension of the stimulation was completed. The percentage of observation intervals with chin wetness was low through the different intervention phases (i.e., including the phase with the 16-second stimulation appendix).
Lancioni et al. (2011a) carried out a study with a 19-year-old woman, who was described as being in the severe-to-profound range of ID. She was not ambulatory, had minimal residual vision, and did not possess specific forms of communication. Drooling had apparently been always present in her condition, as she usually had abundant salivation, swallowed only sporadically, and was not used to wipe her mouth. The technology was stored inside a napkin that she wore. The napkin had a horizontal folding line, and the participant could turn the lower part of it toward her mouth/chin to wipe the saliva away. In using the napkin, she was initially required to activate one of the two pressure microswitches inside it. This was sufficient to turn on a microprocessor connected to an MP3 device, and thus ensure a 12-second period of preferred stimulation (music and songs). Once responding had been strengthened, an appendix of low-impact stimuli was added to the 12-second period of preferred stimulation. This appendix was gradually extended to 10 seconds so that the total stimulation period would finally last 22 seconds. During the last intervention phase, sessions in which activation of one of the two pressure microswitches was sufficient to produce stimulation were alternated with sessions in which the activation of both pressure microswitches was required. Sessions lasted 15 minutes. Data showed that the participant learned to produce the wiping responses in a consistent manner. The frequency of responses per session settled slightly above 30. The percentages of observation intervals with wet chin were always below 20 with a significant difference in favor of those recorded in sessions in which the activation of both pressure microswitches was required.
Lancioni et al. (2011b) implemented a program with two men of 46 and 19 years of age, respectively. The older man was considered to be in the severe-to-profound range of ID, presented with minimal residual vision, and had forms of echolalic speech. The younger man was rated in the severe range of ID, could understand verbal instructions, and used manual signs to make requests. Drooling had been a consistent feature for both men, given their abundant salivation and virtual absence of swallowing and mouth cleaning responses. Both participants used napkins such as those mentioned earlier, which included pressure microswitches and MP3 devices. Initially, mouth-wiping responses allowed the participants to obtain 10 or 15 seconds of preferred (musical) stimulation. Subsequently, an appendix of lower-grade stimuli was added to the preferred stimulation. The appendix, which was extended to 10 or 15 seconds, consisted of daily stimuli presented at an intensity of 15–20 dB lower than that of the preferred stimuli. The sessions lasted 10 and 30 minutes for the two participants, respectively. Data were highly satisfactory with both participants. In fact, they were able to largely control the effects of their drooling with relatively moderate response frequencies.