Repeated onabotulinum neurotoxin A injections for drooling in children with neurodisability

AIM

To evaluate the effect of repeated onabotulinum neurotoxin A injections for the treatment of drooling in children with neurodisabilities.

METHOD

This was a retrospective cohort study, in which the first, second, and third onabotulinum neurotoxin A injection were compared within children treated between 2000 and 2020. Primary outcomes included drooling quotient, visual analogue scale (VAS), and treatment success defined as ≥50% reduction in drooling quotient and/or VAS 8 weeks after treatment. Each outcome was obtained at baseline and 8 weeks posttreatment.

RESULTS

Seventy-seven children were included (mean age at first injection: 8y 3mo, SD 3y 7mo, range 3-17y; 44 males, 33 females; 51.9% with cerebral palsy, 45.5% wheelchair-bound). The objective (drooling quotient) and subjective (VAS) effect after the second injection was lower compared to the first injection. The third injection showed less objective and significantly less subjective effect compared to the first injection. An overall success rate of 74.0%, 41.6%, and 45.8% were found for the first, second, and third injection respectively.

INTERPRETATION

Although onabotulinum neurotoxin A remained effective throughout the entire treatment course, there is less effect of subsequent onabotulinum neurotoxin A injections compared to the first. Although there might be a loss of effect after repeated injections, there is continued improvement for most children. What this paper adds Repeated injections show a diminished treatment effect after the second injection. A continued improvement is seen in most patients.

Submandibular duct ligation after botulinum neurotoxin A treatment of drooling in children with cerebral palsy

AIM

To assess: (1) the effect on drooling of bilateral submandibular duct ligation as surgical therapy after the administration of submandibular botulinum neurotoxin A (BoNT-A) for excessive drooling and (2) the predictive value of treatment success with BoNT-A on treatment success after bilateral submandibular duct ligation.

METHOD

This was a within-participant retrospective observational study in which 29 children with severe drooling (15 males, 14 females) received BoNT-A treatment at a mean age of 9 years 6 months (SD 2y 5mo), followed by bilateral submandibular duct ligation at a mean age of 10 years 11 months (SD 2y 4mo). Fifteen children were diagnosed with cerebral palsy (CP), with 12 children classified in Gross Motor Function Classification System levels IV and V. The 14 children without CP had non-progressive developmental disorders. The primary drooling severity outcomes were the Visual Analogue Scale (VAS; subjective assessment) and drooling quotient (objective assessment). Measurements were taken before each intervention and again at 8 and 32 weeks.

RESULTS

The VAS was significantly lower after bilateral submandibular duct ligation at follow-up compared to BoNT-A treatment (mean difference -33, p≤0.001; 95% confidence interval [CI]=-43.3 to -22.9). The mean drooling quotient did not significantly differ between BoNT-A treatment and bilateral submandibular duct ligation at follow-up (3.3, p=0.457; 95% CI=-4.35 to 9.62) or between 8 and 32 weeks (4.7, p=0.188; 95% CI=-2.31 to 11.65).

INTERPRETATION

BoNT-A treatment and bilateral submandibular duct ligation are both effective treatment modalities for drooling. At 32-week follow-up, subjective drooling severity after bilateral submandibular duct ligation was significantly lower compared to previous BoNT-A injections in participants. However, treatment success with BoNT-A is no precursor to achieving success with bilateral submandibular duct ligation.

WHAT THIS PAPER ADDS

Bilateral submandibular duct ligation is an effective therapy for drooling after treatment with botulinum neurotoxin A (BoNT-A). Treatment success with BoNT-A is not a predictor of successful therapy with bilateral submandibular duct ligation.

Changes in severity and impact of drooling after submandibular gland botulinum neurotoxin A injections in children with neurodevelopmental disabilities

AIMS

To examine changes in objective and subjective drooling severity measures after submandibular botulinum neurotoxin A injection in children with neurodevelopmental disabilities, explore their relationship, and evaluate if clinically relevant responses relate to changes in the impact of drooling.

METHOD

This longitudinal, observational cohort study involved 160 children (92 males, 68 females; 3-17y, mean 9y 1mo, SD 3y 6mo) treated between 2000 and 2012 at the Radboud University Medical Center, Nijmegen, the Netherlands. Repeated measures analysis of variance was used to compare the 5-minute Drooling Quotient (DQ5) and Visual Analogue Scale (VAS) for drooling severity pretreatment and posttreatment, and Pearson's rho to assess their association. A parent questionnaire was used to assess drooling impact in responders (defined as ≥50% reduction in DQ5 and/or ≥2 SD reduction in VAS for drooling severity 8wks postintervention) and non-responders.

RESULTS

One hundred and twelve children (70%) were responders. Their mean VAS for drooling severity and DQ5 scores were significantly lower 32 weeks postintervention compared to baseline. At baseline, the VAS for drooling severity-DQ5 relationship was 'weak' (r_s =0.15, p=0.060), whereas it was 'fair' at 8 weeks (r_s =0.43, p=0.000) and 32 weeks (r_s =0.30, p=0.000). For responders, a significant change was found regarding the impact of drooling on daily care and social interactions at 8 weeks after intervention; most of these effects were maintained at 32 weeks.

INTERPRETATION

A clinically relevant response based on a combination of objective and subjective measures of drooling severity was accompanied by positive changes regarding the impact of drooling on daily care and social interactions.

WHAT THIS PAPER ADDS

Botulinum neurotoxin A injection into the submandibular glands reduced drooling severity in 70% of children with neurodevelopmental disabilities. Objective (5-minute Drooling Quotient) and subjective (Visual Analogue Scale for drooling severity) measures correlated 8 and 32 weeks after treatment. Objective and subjective measures complemented each other when changes in drooling severity were assessed. Reduced drooling severity was accompanied by positive changes with regard to the impact of drooling.

Thickened saliva after effective management of drooling with botulinum toxin A

AIM

The aim of this study was to evaluate the rheological properties of saliva after submandibular botulinum toxin type A (BoNT-A) injections.

METHOD

We enrolled 15 children (11 males and six females; age range 3-17 y, mean age 9 y 10 mo) diagnosed with spastic (n=9) or dyskinetic (n=6) quadriplegic cerebral palsy (CP); Gross Motor Function Classification System level IV or V; and two children with intellectual disability (IQ<70) who experienced moderate to severe drooling. Salivary flow rate and drooling quotient were measured at baseline and at different times after BoNT-A injections up to 24 weeks. The mucin concentration of saliva was analysed before and after BoNT-A treatment.

RESULTS

Both submandibular salivary flow rate (baseline 0.38 mL/min; 24 wks after injection 0.26 mL/min) and drooling quotient (baseline 42.5%; 24 wks 28.80%) were substantially reduced, with a concomitant increase in mucin concentration within 8 weeks after BoNT-A injection (from 0.612 to 1.830 U/mL). The parents of nine children observed thickened saliva. Swallowing and chewing were problematic in seven children. Two of these children needed treatment with mucolytics because of pooling of thickened saliva in the throat.

INTERPRETATION

When making decisions about the use of BoNT-A, the risk of problems with masticatory and swallowing functions as a result of thickening of saliva after BoNT-A treatment should be taken into account.

Drooling in cerebral palsy: hypersalivation or dysfunctional oral motor control?

AIM

To investigate whether drooling in children with cerebral palsy (CP) in general and in CP subtypes is due to hypersalivation.

METHOD

Saliva was collected from 61 healthy children (30 males, mean age 9y 5mo [SD 11mo]; 31 females, mean age 9y 6mo [1y 2mo]) and 100 children with CP who drooled (57 males, mean age 9y 5mo [3y 11mo], range 3-19y; 43 females, mean age 10y 1mo [4y 9mo], range 4-19y), of whom 53 had spastic, 42 had dyskinetic, and five had ataxic CP. Almost all children were affected bilaterally, and 90 of them were at Gross Motor Function Classification System levels III or higher. The saliva was collected by the swab saliva collection method. The intensity of drooling was evaluated using the drooling quotient.

RESULTS

No difference was found in the flow rates, age, or sex between healthy children and children with CP who drooled. On additional subgroup analysis, the flow rates of children with dyskinetic CP differed statistically from those of healthy children (submandibular p=0.047, parotid p=0.040).

INTERPRETATION

This study supports the finding in previous studies that no hypersalivation exists in children with CP who drool. Dysfunctional oral motor control seems to be responsible for saliva overflow from the mouth, whereas increased unstimulated salivary flow may occur in children with dyskinetic CP as a result of hyperkinetic oral movements.

Drooling in children with cerebral palsy: effect of salivary flow reduction on daily life and care

The purpose of this study was to investigate the effect of salivary flow reduction on daily life and provision of care in children with cerebral palsy (CP). Parents of children with CP were asked to fill in a questionnaire on the impact of drooling on the daily life of their children and their families and the data were then analyzed. Forty-five children with severe drooling (28 males, 17 females; mean age 9y 5mo [SD 3y 7mo]; range 3 to 16y) were monitored before and after receiving medication (scopolamine and botulinum toxin) to reduce salivary flow. Type of CP included hypotonia (n = 1), spastic paresis (n = 27), and mixed motor disorders with spastic and dyskinetic paresis (n = 17). Eight children were independently ambulant and 37 children were wheelchair users. Thirty-four children had learning disability with a developmental age of below 6 years. Six participants dropped out of the study; data on 39 children were analyzed. Results showed that anticholinergic agents effectively reduced salivary flow. Drooling diminished substantially and this was accompanied by a significant reduction in care needs, making daily care less demanding. The amount of reported damage to communication devices and computers decreased. In addition to the evaluation of primary variables, such as the salivary flow rate, investigation of impact of drooling on daily life provides useful information about the outcome of treatment for reduction in drooling.