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DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY Worster-Drought syndrome: poorly recognized despite severe andpersistent difficulties with feeding and speech MARIA CLARK1,2 | REBECCA HARRIS1 | NICOLA JOLLEFF1 | KATIE PRICE1 | BRIAN GR NEVILLE2 1 Great Ormond Street Hospital for Children NHS Trust, London. 2 Neurosciences Unit, Institute of Child Health, University College London, UK Correspondence to Professor Brian GR Neville at The Wolfson Centre, Mecklenburgh Square, London WC1N 2AP, UK. E-mail: [email protected] AIM Worster-Drought syndrome (WDS), or congenital suprabulbar paresis, is a permanent move- Accepted for publication 17th June 2009.
ment disorder of the bulbar muscles causing persistent difficulties with swallowing, feeding, speech, and saliva control owing to a non-progressive disturbance in early brain development.
As such, it falls within the cerebral palsies. The aim of this study was to describe the physical and neuropsychological profiles of children with WDS.
METHOD Forty-two children with WDS (26 males, 16 females; mean age 7y 10mo, SD 3y 1mo; range 2y 6mo to 16y 5mo) were studied prospectively using a standard protocol.
SOMA Schedule for Oral–Motor Assessment RESULTS All of the children had severe bulbar dysfunction; 36 out of 42 had feeding difficulties and 23 of 38 had unintelligible speech, which was poorly compensated for by augmentative com-munication. There were accompanying disturbances in cognition (mean non-verbal IQ 59), behav-iour (12 ⁄ 40 attention-deficit–hyperactivity disorder [ADHD]), social communication (8 ⁄ 42 autism),and epilepsy (12 ⁄ 39). The severity of bulbar dysfunction and impact of additional impairmentsmade it difficult to use formal assessments.
INTERPRETATION WDS causes severe and persistent bulbar dysfunction that is often accompa-nied by additional impairments, as in other cerebral palsies. Speech prognosis is particularly poor.
Early diagnosis with appreciation of the underlying neurology would encourage critical evaluationof interventions and long-term planning to improve outcome.
WDS was originally defined as congenital suprabulbar pare- neuron, or due to motor unit or muscle disorder, are easily sis,1 without specifying the level of lesion. However, the term excluded as the tongue is weak, wasted, and tremulous, and has been used for acquired lesions,2 functional epileptogenic jaw jerk is absent. Structural causes must be considered. Ton- variants,2 and even isolated dysarthria.3 There are only a few gue tie is simple to eliminate as a cause of reduced tongue retrospective case series, if the term is confined to congenital movement as it does not affect the lips, jaw, or palate. How- spastic paresis (great difficulty using bulbar muscles with no ever, structural causes of velopharyngeal insufficiency (e.g.
wasting or fasciculation; exaggerated jaw jerk) causing perma- occult submucous cleft) can cause confusion, as some children nent bulbar dysfunction, resulting in disorders of saliva con- compensate for the loss of air through the nose by articulating trol, swallowing, airway protection, feeding, and speech.1,4,5 at the vocal folds rather than with the tongue or lips. However The underlying abnormality is thought to be in the perisylvian again, careful examination would show that oromotor move- cortex (congenital bilateral perisylvian polymicrogyria [CBPP] occurs in around 15 ⁄ 100 of affected individuals5) and may be a Another important differential diagnosis is childhood continuum of bilateral perisylvian syndromes.6,7 A genetic apraxia of speech or developmental verbal dyspraxia in which aetiology appears to be important in about 15 ⁄ 1008 of cases the precision and consistency of movements underlying speech and there is evidence of a vascular aetiology in some individu- are impaired. This leads to inconsistent error production, impaired coarticulatory transitions between sounds and sylla- The differential diagnosis is relatively straightforward.
bles, and inappropriate prosody.9 There is no weakness on for- There must be difficulty from infancy (although exact expres- mal examination and no difficulty with involuntary motor sion varies with severity and developmental stage), which control of chewing, or swallowing, etc. However, many chil- excludes acquired and progressive conditions. The main dren given this diagnosis also have ‘messy eating’ or mild drib- motor involvement is bulbar, distinguishing it from suprabul- bling.9 This can cause confusion as the pyramidal motor bar palsy as part of another diagnosis, such as severe spastic speech problems in WDS may be manifest as symptomatic tetraplegia. Cases in which bulbar involvement is lower motor dyspraxic or dysarthric speech, and the distinction from ª The Authors. Journal compilation ª Mac Keith Press 2009 developmental verbal dyspraxia rests on the severity and mul- reflected the number of valid data points. v2 tests were used to timodality of the bulbar involvement, confirmed by signs of explore relationships between categorical variables; t-tests WDS meets the international criteria for cerebral palsy (CP), being a ‘permanent, but not unchanging disorder of movement and of motor function due to a non-progressive interference, lesion or abnormality of the developing ⁄ imma- The results are shown in Table I. Children presented early ture brain’. Affected children commonly have a mild tetraple- (mean 7mo) but were diagnosed late (mean 5y). A family his- gia causing late motor milestones, although they do walk.5 As tory of WDS (4 ⁄ 36), speech delay (5 ⁄ 36), or seizures (9 ⁄ 36) with other types of CP, there are often additional impairments was common. Twelve out of 39 participants had epilepsy, in behaviour and learning, and epilepsy may be present.5 A CP often with multiple seizures (5 ⁄ 12) and a history of convulsive study10 identified WDS in 0.9 ⁄ 100 of participants, suggesting status (5 ⁄ 12). Twelve out of 40 participants had a diagnosis of a prevalence of 2 to 3 per 100 000 live births. From our expe- ADHD and 8 ⁄ 39 had a diagnosis of autism made by local rience this is probably an underestimate, as late diagnosis iscommon (mean age 5y in this study), many CP registers use5 years as the optimal ascertainment age,11 and most do not recognize WDS. Furthermore, many children are not diag-nosed but managed entirely on the basis of their symptoms. As a consequence, systems for assessing and managing this symp- tom complex are mostly not available.
Thirty-nine children older than 4 years with congenital supra- bulbar paresis were consecutively recruited over 18 months at Great Ormond Street Hospital from clinics for augmentative communication, neurodevelopment, dysphagia, and neurol- ogy. Four years was chosen as the minimum entry age because motor findings can be transient in younger children (any motor speech problem should be evident by this age), and to improve compliance with assessment. In addition, three youn- ger siblings (2y 6mo, 2y 8mo, 3y 5mo) with a secure diagnosis were enrolled. In total, 42 children with congenital suprabul- bar paresis (26 males, 16 females; mean age 7y 10mo; SD 3y 1mo; age range 2y 6mo to 16y 5mo) were studied prospec- This study was approved by the Research Ethics Committee for Great Ormond Street Hospital and the Institute of Child Health. Informed consent was received from all parents or guardians before assessment. Anonymized data were used Participants followed a standard protocol (Table SI, supple- mentary material published online) with data collected by four speech and language therapists, two paediatric neurologists, and a radiologist. Feeding (28 children) and swallowing (11 children) studies were restricted to those less severely affected, and contraindicated when clinical assessment suggested that they may be unsafe. Reliability was monitored by independent evaluation of video-recorded assessments, and discrepancies Descriptive statistics were used. In the case of data being Developmental quotient= (age equivalent at assessment ⁄ chronological age at assessment) ·100. WDS, Worster-Drought unavailable for any individual, that individual was removed syndrome; ADHD, attention-deficit–hyperactivity disorder; CI, from analysis of the variable, and the denominator therefore confidence interval; DQ, developmental quotient.
Developmental Medicine & Child Neurology 2010, 52: 27–32 child development teams using ICD-10 criteria. This was con- Table III: History of feeding and associated difficulties gruent with behavioural screening (Strengths and DifficultiesQuestionnaire),12 between the WDS group and normal population across all fivebehaviour scales (independent samples t-test, p<0.001), partic- ularly striking for hyperactivity and peer relationships (Fig- Thirty-eight out of 40 participants had mild pyramidal limb signs (brisk deep tendon reflexes with mild increase in tone but without obvious weakness), with 15 out of 23 in the dyspr- axic range for imitation of gestures13 and 27 out of 28 below the 4th centile for rapid and precise upper limb movements.14 These factors could all affect signing and other augmentative Oromotor examination, drooling, and feeding All children had multiple abnormalities on oromotor examina-tion of the lips, tongue and jaw (restricted jaw opening pre-cluded systematic observation of the palate) (Table II). Eleven had difficulty establishing milk feeds as infants (compared with out of 20 children had dissociation of facial expressions (e.g.
1 ⁄ 10 to 15 ⁄ 100 of infants in the general population15), 40 out could not smile on request or through imitation but produced of 42 participants experienced problems during weaning, and a reflex smile in response to emotion), and 10 of 38 had a jaw 10 of 42 required prolonged tube feeding. Most reported man- aging more complex food over time. At the time of assessment, Eleven children had required neonatal care for swallowing 5 of 42 participants were dependent on tube feeds, 31 out of problems and compromise to their airway, including one child 42 needed dietary modification, and only 6 of 42 managed a who subsequently underwent an epiglottopexy. All 42 children full adult diet. However, many children who required dietary drooled beyond 2 years. This improved and become intermit- modification perceived themselves as ‘managing a careful nor- tent with age, often returning whenever the child had to con- mal diet’ with the caveat that they avoided certain textures centrate (e.g. on school work). Three children had undergone (e.g. apple skins, meat, crisps), chose ‘soft foods’, and chopped submandibular duct transposition with limited success, despite or mashed it well. Many reported oral hypersensitivity to cer- repeat operations in one individual. Twenty-three out of 42 tain textures and also to tooth brushing, defined as causing children had tried but discontinued medication because of unpleasant side-effects and supply issues. Only six children A structured feeding assessment (Schedule for Oral–Motor remained on medication, and then only intermittently on spe- Assessment; [SOMA]16) was attempted in 28 children. Refusal cial occasions. Thirty-two out of 41 participants drooled dur- rates were high, ranging from 5 out of 28 for liquid to 11 of 28 for pure´e. Three children completely refused to undertake the Families tended to underreport feeding issues, but detailed assessment; nine completed the assessment with normal questioning (Table III) revealed that 29 out of 41 participants results, and in 11 assessment was incomplete, with normalresults where tested. Only five children had abnormal scores(three for multiple textures), despite the fact that 21 of the 25 Table II: Oromotor neurological assessment children tested needed dietary modification at the time. Therewas no clear pattern to the abnormalities seen. Thus, SOMA findings did not reflect the reported feeding difficulties.
Informal feeding observation in these 28 children revealed functional difficulties and behavioural adaptations that were not scorable on the SOMA. Children compensated for reduced lip movement by tilting their chin upwards to reduce anterior spill of saliva and food, and by using their hands to achieve lip seal. Similarly, they overcame impaired tongue movements by using their fingers to place food between theteeth or by not chewing food but instead mashing it against the hard palate. Many overfilled the mouth, perhaps compen- sating for food falling out or because of reduced oral aware- ness. Swallowing was often initiated by tipping the head back to use gravity or by placing a supporting hand on their chin.
Lip (closure ⁄ spread ⁄ round ⁄ smacking) Food residues commonly stuck to the hard palate or cheeks aOne child had ankylosis requiring surgery.
and had to be cleared manually after meals otherwise residues Worster-Drought Syndrome Maria Clark et al.
could remain in the mouth, even overnight. Children used their receptive abilities, suggesting that the observed recep- their hands or napkins to mask their mouths during eating so tive–expressive gap was largely a reflection of articulatory diffi- that superficially eating appeared acceptable, and overall they culties that could be overcome with appropriate support.
tolerated significant feeding abnormality.
However, in children with DQ in the normal range, a large Videofluoroscopy was attempted in 11 children. (Table SII) receptive–expressive gap remained, implying that these chil- Two children refused outright and many refused certain tex- dren had not achieved their potential with current provision tures, perhaps reflecting a learned aversion by children with and use of augmentative communication.
feeding difficulties. All nine participants had abnormal assess- By report, many children had received significant direct ments, with seven having multiple abnormalities and two not speech therapy without developing functional speech. How- completing the assessment. The children cooperated best for ever, there were a few children who did acquire some expres- pure´e (3 ⁄ 11 refused) and also had fewest abnormalities for this sive language very late (e.g. four children had no words at 3– texture. Liquids were less acceptable (4 ⁄ 11 refused) and 4y but had 15–20 unclear words by 6–8y). Thirty-two of 42 appeared generally to be more difficult to handle (perhaps as children relied on augmentative communication systems the more rapid transit unmasked the coordination difficulties).
Solids were refused by 8 of 11 children, making results for this Twenty-three children out of 38 were unintelligible at sin- gle word level,17 even to their familiar listeners (Table IV).
Twenty-four of 37 had a severe dysarthric pattern causing dif- ficulty with articulatory placement, especially tongue tip Many of the children had learning difficulties, and on a sounds, hypernasality, and gross nasal escape. They often pro- paired-samples t-test there was no significant difference duced predominantly velar sounds (k, g) made with the back between non-verbal IQ scores (mean=59, confidence interval of the tongue against the soft palate. However, 5 out of 37 par- [CI] 50–68) and receptive developmental quotient (DQ) scores ticipants made more typical dyspraxic-type errors, with vowel (mean=62, CI 52–72). Expressive DQ was extremely difficult distortion, different targets produced on consecutive attempts, to measure owing to intelligibility issues. Preliminary analysis and ‘groping’ for articulatory placement, including one child gave a mean expressive DQ of 40 (CI 35–45) and a significant with bilateral perisylvian polymicrogyria and a family with difference between receptive and expressive DQ scores on a dysarthric and dyspraxic members. The remaining 8 of 37 paired-samples t-test (t[17]=2.57, p<0.02, the g2 statistic [0.28] children could not be categorized and often displayed mixed indicating a large effect size). To examine whether this simply features. Some children had difficulty with voice production, reflected intelligibility rather than true difference in expressive with use of lower register (‘creaky’) voice further impeding intent, nine children across the full receptive DQ range were assessed by the information-carrying content of their commu- Communication was often additionally compromised by nication, including responses through augmentative commu- poor social communication skills, including difficulties with nication (Fig. 1). Augmentative communication allowed less initiating conversation, maintaining a topic chosen by adults, cognitively able children to achieve expressive scores similar to and failing to notice change of topic. However, there was nolink between autism and intelligibility. Independent-samples t-tests were conducted to compare the non-verbal IQ scores for children with autism (mean 50) and those without autism(mean 61), for children with ADHD (mean 56) and thosewithout ADHD (mean 60), and, finally, for those with epilepsy (mean 54) and without epilepsy (mean 62); there were no sta-tistically significant differences.
Table IV: Intelligibility findings for children with Worster-Drought syn- Figure 1: Expressive developmental quotient (DQ; including multimodal communication responses) of nine children compared with their receptive DQ. DQ= (age equivalent at assessment ⁄ chronological age at assess- Developmental Medicine & Child Neurology 2010, 52: 27–32 rates (probably because the children knew their limitations) Five out of 37 children had CBPP. In 13 out of 32 children and did not capture the difficulties or detect compensatory electroencephalography was abnormal, often showing spike– movements, perhaps because the SOMA was devised to assess wave complexes over the Sylvian regions.
oromotor skills during weaning of younger children, and in In 5 out of 13 children (two with CBPP), a tongue electro- WDS the feeding pattern is severely disordered rather than myogram (EMG) was abnormal, showing neurogenic changes delayed. Videofluoroscopy was restricted to less severely suggestive of lower motor neuron involvement, which has affected children to minimize aspiration. Even so, refusal rates been reported before in CBPP.18 There was no significant dif- were extremely high, perhaps because these children were ference between the group with neurogenic changes and those mobile and hyperactive, and had strong food aversion. Despite in whom the EMG was normal in terms of oromotor examina- this, videofluoroscopy gave important information on swal- tion, intelligibility, and current diet, but the neurogenic group lowing that was not available from direct observation.
had higher mean non-verbal IQ (90 vs 53) and mean receptiveDQ (71 vs 47) scores. This might have suggested a non-corti- cal lesion, as found by other groups,19 except that two children These children experienced multiple barriers to communica- (both with non-verbal IQ>75) had CBPP. pH studies carried tion, including motor speech problems, social communication out in four children showed significant reflux.
difficulties, hyperactivity, and conductive hearing loss. In 23out of 38 children, motor speech was so severely affected that the children were effectively unintelligible, a significant, practi- Oromotor examination, drooling, and feeding cal barrier to accessing learning and participating in friendship Oromotor impairments (lip, jaw, tongue) appeared to be inde- groups. Thirty-two out of 42 children used alternative commu- pendent, with the tongue most frequently and severely nication systems, but they often did not achieve their communi- affected. Severe tongue and lip impairments commonly cative potential, with large discrepancies between language understanding and expression, particularly in the case of more reflux, and aspiration, although not reaching statistical signifi- able children. This communication gap may have resulted from cance. Severely restricted jaw movement was associated with a difficulties in accessing equipment appropriately matched to history of aspiration (v2, p=0.042), and during feeding assess- the child’s profile21 or in obtaining adequate support for effec- ment these children needed help to stabilize their jaw to allow tive equipment use, as well as from the effects of other aspects safe feeding. However, there was no link between degree of of the child’s profile (e.g. hyperactivity, dyspraxia).
oromotor examination abnormality and receptive language, The observed severity and longevity of intelligibility difficul- non-verbal IQ, neuropsychological profile, sex, or presence of ties mean that all direct speech work should be carefully evalu- ated for improvements in functional intelligibility. It may be Thirty-nine children out of 41 (39 ⁄ 41) had significant best to assume that augmentative and alternative channels of drooling, which has previously been correlated with reduced communication will be required and to introduce these early swallowing and oromotor control.20 Where performed, sur- so that children have the ‘tools’ to develop expressive commu- gery appeared unhelpful. Twenty-six out of 32 children chose nication.22 It is difficult for this group to achieve successful use not to take medication and used behavioural techniques such of alternative channels of communication because of their as chin posture, wiping the mouth, and conscious swallows to reduced fine motor, attention, and social communication skills and their normal mobility; therefore, devices need to be robust Forty out of 42 participants had problems with suckling and and portable, and trial of loan equipment may be necessary.
weaning, but were often not diagnosed until school age. Thosewith difficulty from birth were significantly more likely to also have a history of gastro-oesophageal reflux (v2, p=0.01) and Completion of assessments was difficult for many reasons aspiration (v2, p=0.04). Children and parents become habitu- (food aversion and inability to understand instructions, to ated to feeding difficulties so that history-taking had to ask comply with adult direction, to sustain attention, or to repeat specifically about feeding milestones, dietary modification, items for scoring purposes), although none reached signifi- and eating behaviour, and corroborate this with direct clinical cance, perhaps because of small numbers or because most of observations of feeding using the child’s preferred foods.
the group had some difficulty in these areas. Assessment by Reported oral hypersensitivity appeared to be a behavioural experienced clinicians using real situations appeared to be the rejection of certain stimuli based on previous unpleasant expe- riences (including gastro-oesophageal reflux and constipation),rather than a neurological sensory issue. In some children it further compromised feeding and made dental and oral Children with WDS commonly present to community ser- vices with feeding problems and speech delay. Early diagnosis Direct feeding observation gave better information than of this neurological condition and its identification as distinct formal assessment, and showed the children using many com- from a maturation or developmental disorder is important pensatory strategies to mask difficulties and consciously because oromotor difficulties are likely to persist and do not choosing less challenging food. The SOMA had high refusal appear to respond to conventional therapies, and affected chil- Worster-Drought Syndrome Maria Clark et al.
dren may have multiple additional impairments that require and evaluate integrated use of speech, signing, facial expres- appropriate multidisciplinary support to optimize outcome.23 Feeding problems are extremely important, leading to poor growth and developmental outcomes,24 decreased motivation, increased irritability, serious pulmonary consequences,25 and This study was supported in part by a grant from Sport Aiding Medi- stressful mealtimes. Professionals actively need to ask about cal Research for Kids (SPARKS). The parent support group has been specific feeding behaviours and milestones as families often a significant source of information and encouragement. Professor S become habituated to the abnormal situation. There is a high Reilly helped with the initial concept and Mike Clarke helped with incidence of non-compliance with formal assessment, so real- data collection. Great Ormond Street Hospital for Children NHS time observation of feeding is invaluable. The feeding difficul- Trust received research and development funding from the NHS ties are complex and may include gastro-oesophageal reflux, aspiration, constipation, dehydration, malnutrition, and sec-ondary behavioural components, as well as difficulties with drooling, dental hygiene, and oral hypersensory issues.
Additional supporting information may be found in the online version The prognosis for speech development for children with WDS is poor, and there is always a marked discrepancy Figure S1: Strength and difficulties questionnaire results for chil- between receptive and expressive language skills. Both dys- dren with Worster-Drought syndrome compared with the normal arthric and dyspraxic elements contribute to their intelligibil- ity difficulties, and, although they are reported not to respond to direct speech work, interventions shown to be useful for children with CP and dyspraxia26 could be considered with Table SIII: Communication methods used by children with Wor- careful evaluation of results. Early, appropriate, and well-sup- ported alternative communication programmes that cater for Please note: Wiley-Blackwell are not responsible for the content or ADHD, autism spectrum, and motor impairments would be functionality of any supporting materials supplied by the authors. Any important to optimize communicative outcome. Outcome queries (other than missing material) should be directed to the corre- measures would need to include all communication functions 1. Worster-Drought C. Suprabulbar paresis. J Laryngol Otol 11. Cans C, Dolk H, Platt MJ, Colver A, Prasauakiene A, Krage- cranial nerve involvement, and ocular motor apraxia. Dev Med loh-Mann I. Recommendations from the SCPE collaborative 2. Christen HJ, Hanefeld F, Kruse E, Imha¨user S, Ernst JP, group for defining and classifying cerebral palsy. Dev Med 20. Senner J, Logemann J, Zecker S, Gaebler-Spira D. Drooling, Finkenstaedt M. Foix–Chavany–Marie (anterior operculum) Child Neurol 2007; 49:(Suppl. 109) 35–38.
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