 |
Personal
Practice |
Indian Pediatrics 1999;36: 887-890 |
Evaluation of a Child with Communication Disorder |
| S. Aneja |
From the Department of
Pediatrics, Lady Hardinge Medical College and Associated Kalawati Saran Children's
Hospital, New Delhi 110 001, India. |
Pediatricians often see a preschooler who has not started speaking or a child who has deviant language. The evaluation of a child with this problem is not easy and requires help from an audiologist and speech therapist. However, the first examination is done by a Pediatrician who is responsible for evaluating whether the language delay is within normal limits or else it requires further examination by a speech therapist. The pediatrician is also in all likelihood entrusted with the job of answering various queries by the parents regarding the prognosis. The prevalence of communication disorders (hearing, voice, speech and language) is not known. Communication disorders are low visibility problems and are often under- diagnosed or identified late. Mc Keith and Rutter estimated on the basis of literature review that 1% of all children came to school with a marked language handicap(1). Definitions Language: Meaningful use of a symbolic code (words, phrases, gestures) which would be understood by one who knows that code. Language can therefore be gestural, spoken or written or Braille. The purpose of language is communication but all communications is not language. Voice is vibrating air column that is dependent upon the ability to move air through the trachea and larynx. Speech: Use of systematized vocalization to express verbal symbols or words. Semantics refers to understanding of meaning of ideas in conversation whereas Pragmatics refers to adaptation of behavior and language rules to social situations. Syntax refers to sentence structure in a particular language. Anatomy of Normal Language Human communication and its disorders have three interrelated domains; (i) The reception of sensory input which carry information; (ii) Motoric expression_the expressive aspect of communication; and (iii) Central nervous system's processing of these sensory and motor functions, which formulates the information into language. The left hemisphere is responsible for language skills in 94% of right handed and 75% of left-handed adults. There are 3 main areas in left hemisphere that are specialized for language _ 2 anterior areas (Broca's area and supplementary motor cortex) and one posterior area (Wernicke's area) where it is compared with stored language data to interpret the meaning. A response is formulated and transferred by arcuate fasciculus to the anterior area where the motor response is co-ordinated (Fig. 1). Hemispheric specialization for language begins before birth but programming of language function occurs over the years. In children with unilateral brain injury, language functions can be programmed in either hemisphere. In contrast to adults who show marked linguistic deficits with acquired lesions in left |
|
Fig. 1. Pathway to Communication. |
perisylvian region, the effect on language development of congenital unilateral lesions is milder(2). Delays are seen with both left and right hemispheric insults although different aspects of language are affected. Catch up growth in language acquisition is common and deficits diminish over time(3). It should be remembered that language function entails a complex interaction of both language specific and general cognitive abilities. Normal development of speech and language requires that children have normal hearing, and ability to perceive the sounds of speech, normal fine motor development of larynx, lips, tongue, jaw and palate and they develop a mental representation of objects and activities important to them. Thus in the process of language development, the domains of cognition, social adaptation, and perceptual motor functions interact with each other, influencing and enhancing the growth of the other. Many language tasks require participation of a host of cognitive processes such as short-term memory, problem solving and processing abilities. Electrophysiological studies involving auditory event related potentials have shown that function of mechanism within both hemispheres is important in early postnatal life for later language development(4). Normal Language Acquisition Human beings have an innate desire to communicate with their social partners. Long before the children start to talk they are skilled in use of eye contact, facial expressions and non-verbal gestures to communicate. At around 9 months children begin to display preverbal gestural communication by pointing at a desired object or for catching the attention of mother to something interesting. These gestures foster conversation and create a backdrop for learning of new words. Phonological development progresses simultaneously from simply crying and cooing (2-4 months) to squealing, whispering and babbling (7-10 months). As further sensorimotor development takes place the child's knowledge of objects and actions and their corresponding words increases. The rate of development of language skills in preschool age is truly astonishing. From an average vocabulary of 20 words at 18 months which consists of mainly nouns (names of family members, food) and a few verbs (actions) the toddler starts putting two words together (phrases) and then begins to make sentences (2 years). At this age he/she often omits prepositions and adjectives and language is telegraphic. As the child grows the language becomes more complex and conforms to the rules of grammar(5). The pace of development is variable as is true of other areas of development. In general girls acquire language skills earlier than boys do. Table I lists the warning signs of language disorder. The auditory environment of the infant will determine the ability to discriminate the sound patterns or phoneme. The quality of the linguistic exposure for the first few years of life determines the quality of linguistic ability to a large extent. |
Table I__Warning Signs of Language Problems. • No words at 18 months |
Classification of Speech Language Disorders A number of classifications have been suggested, however none is without merit or demerit. Fig. 2 is a simplified classification of types of speech and language problems. Further discussion refers to the common types and their diagnosis in clinical practice. It is also important to remember that the classification into different groups is not watertight, there being a lot of overlap between these groups. If the linguistic exposure is deficient this can result in defective development of the child's language. Similarly diminished expressive abilities diminish the infant's ability to communicate and consequently change the way in which the caregivers talk to the child. The infant whose cry is abnormal will elicit different response from those with a normal cry. This explains why the children who have speech problems in the first year of life have deficiency in the receptive language also. The most common anatomic abnormality of speech tract that is apparent at birth is cleft palate. Most of the infants with cleft palate have a high prevalence of otitis media and subsequent conductive hearing loss. Thus there is synergistic combination of both receptive and expressive component of communication. Disorders of the voice are usually obvious early in life. Voice disorders may be due to congenital malformations of larynx, e.g., stenosis, web or cleft, or due abnormal neuromuscular control of larynx. Change in the cry of the infant is an indication of pathology of larynx or trachea. The most common speech abnormalities in children are associated with neuromotor dysfunction. These include dys-arthria associated with cerebral palsy, dysfluency disorders, e.g., stuttering. The dysarthria in a child with cerebral palsy is associated with drooling and swallowing difficulties, besides other sensory and motor deficits that coexist in such children. Stuttering is a disorder of rhythm of speech. Some degree of dysfluency is common between the 3-4 years of age. Persistent and worsening stuttering beyond age of 4 years and presence of grimacing with blocking of speech should be taken seriously. The child has the ability to formulate the language but is unable to say it because of involuntary, repetitive prolongation or cessation of a sound. Stuttering occurs more frequently in children with other types of developmental language disorder (DLD). The exact cause is unknown, however genetic predisposition has been observed. Acquired stuttering after brain injury is relatively uncommon in children. Developmental Language Disorders These are the commonest types of developmental disorders in children affecting approximately 5% children. DLD is defined as failure to acquire language in absence of hearing loss, brain injury or other medical conditions, and in presence of verbal skills two standard deviations below non-verbal skills(6). It should be noted that DLD implies dysfunction of language skills beyond articulation disorders. This group includes children in whom there is delayed langauge development that resolves spontaneously or with help. The variability in language acquisition makes it sometimes difficult to distinguish idiosyncratic language delay from DLD in small children. However failure to develop normal expressive language at three |
Fig. 2. Classification of Speech and Language Disorders. |
years should be considered pathological(7). The classification of language disorders is still evolving and many classification systems have been proposed(8,9). DLD has been classified into three broad types_expressive only, mixed receptive-expressive and higher order processing variety(6). Expressive and mixed receptive expressive disorders involve phonology and phonology syntax aspects of language, respectively. Higher order processing disorders mainly affect semantic and pragmatic aspects of language. Combined receptive-expressive DLD were observed to be commonest type of DLD in children referred to a child development center for speech and language problems(10). Developmental Verbal Dyspraxia: This is a subtype of expressive DLD. It has been desrcibed as a neurogenically based motor deficit which inhibits the abilit to carry out co-ordinative movements of the respiratory, laryngeal and oral muscles for articulation in the absence of impaired neuromuscular function. The onset of language is delayed and speech is described as `dilapidated' and labored. Soft neurological signs such as decrease in the rate of alternating movements of tongue and hands are often seen in this group of children. Phonological Production Deficit: This expressive only subtype is characterized by impairment in phonology and unintelligible speech. Patients have a well developed vocabulary and comprehension is normal. Phonological Syntactical Disorder: This is a subtype of mixed receptive expressive disorder and the most common variety of DLD seen in practice, in which children have selective difficulties with language structure and form but have normal language content. Some authors have classified it under expressive DLD. Thus, they have normal inner language and urge to say appropriate words but have difficulty with phonology and syntax. Boys are more frequently affected than girls. Children with this disorder are often impossible to understand because sounds produced are unrecognizable. Compre |
hension is spared and semantic skills are intact. This disorder resembles Broca's aphasia in the adult. There is a wide range of severity with some children having unintelligible speech and others having only mild problems with phono-logy. Language does improve slowly but the children may have difficulty in reading. Verbal Auditory Agnosia is a subtype of mixed receptive expressive disorder. In this case, there is a virtual absence of verbal understanding and an accompanying absence of speech. It is an uncommon condition and undiagnosed hearing loss must be excluded before making the diagnosis. These patients are able to process visual symbols of language but are not able to decode phonology. Language Delay with Hearing Loss The number of children whose language is affected by hearing loss is difficult to ascertain. Approximately one child per thousand is thought to suffer from sensorineural hearing loss with impairment of langauge development. Then there are a large number of children who have intermittent hearing loss (as in conductive deafness due to glue ear) who may have delay in language development but not language disorder. Infants with cleft lip and palate, even those with submucosal cleft, have greater susceptibility to otitis media. Hearing loss acquired after development of language has lesser effect on verbal skills but does interfere in understanding spoken language. In contrast prelingual deafness has profound effect on development of language even with early diagnosis and is characterized by limited vocabulary and sentence structure. Early babbling sound are normally produced even in deaf children but these do not progress to show the complexities of speech of normal child. If the impairment is mild, speech may develop but is limited by poor articulation. However, non-verbal skills are normal and these children are experts at using non-verbal cues, gestures and facial expressions to join in social interaction. Indeed non-verbal cues are sometimes so well developed that hearing deficit may go unnoticed for a long time. Mild hearing loss affecting higher frequencies are more likely to be missed on clinical examination alone. The common causes of progressive and acquired loss after the first month of life are genetic, meningitis and head trauma. The infants are particularly more prone to develop hearing loss following modest head injury not associated with fracture of base of skull. Language Delay with Mental Retardation Global delay in development will result in impairment of all aspects of child's development including fine motor, language and social skills. Children with mental retardation show delays in all areas of language and the extent of deficit varies with IQ. As cognitive impairment becomes profound the language impairment becomes severe. In children with IQ less than 50 there is marked delay in language. However, non-verbal skills are commensurate with mental age and they can usually communicate with simple gestures and facial expressions. Social development and play is appropriate for mental development although ritualistic play may be seen in profound mental retardation. Autism Extremely delayed language acquisition or in some cases regression of early language development is the presenting symptom in autism. The diagnosis of autism is based on 3 criteria(8): (i) Delayed and deviant social development; (ii) Delayed or deviant language development which is out of keeping with child's non verbal skills; and (iii) Presence of obsessional rituals and routine and general resistance to change. The autistic children do not respond to when called, do not communicate with gestures or facial expressions. In general they lack a desire to communicate. Autistic children tend to play alone and have unimaginative and impoverished play. Those who have some speech have aberrant prosody, e.g., speaking in high pitched squeaky voice or robotic tone. Echolalia persists for a long time in these children. All children with autism have some language deficit. However, the extent of this deficit and handicap is variabale. The term "semantic pragmatic disorder" is reserved for milder forms of autistic children and is used to describe a group of children who use superficially complex language with clear articulation but whose use of understanding of language and rules of social communication are deficient. Acquired Epileptic Aphasia Acquired epileptic aphasia (Landau-Kleffner's Syndrome) is defined as an acquired aphasia in association with an abnormal EEG demonstrating spikes, sharp waves or spike and wave discharge which is usually bilateral and occurs predominantly over the temporal and parietal region. Upto a quarter of patients may not have clinical seizure(11). The language development is normal prior to the onset of seizure or aphasia. The peak age of symptoms is between 5-7 years. Most children with this disorder have severe receptive and expressive deficit amounting to verbal auditory agnosia. The prognosis of seizure control and normalization of EEG is good but recovery of language is variable. Corticosteroids and sodium valproate have been shown to be somewhat effective. Clinical Evaluation The aims of evaluation are: (a) Detecting the presence of communication disorder and characterizing its nature; (b) exploring the potential medical cause; if any: (c) Developing a medical management plan and referral to audiologist and speech therapist. Clinical history should include enquiries about the way communication developed between the infant and the parent and the general development of the child. Besides the usual developmental history details as to the feeding history provide early indications of neuromotor deficits which are pointers of developmental verbal apraxia. The physician should be able to ascertain whether the child has primarily a disorder affecting language and speech or there is global delay. The following variabales should be taken into account to evaluate a child with delayed language development: (i) Hearing and level of comprehension; (ii) The level of expressive language; (iii) Non-verbal communication; (iv) Social adaptation; (v) Play development; (vi) Cognitive abilities; (vii) The presence of rituals and obsessiveness; (viii) Behavior. The trigger questions to be asked from parents (Table II) will elicit reasonable information of these domains and provide a probable diagnosis. Inner language can be assessed in a non- verbal child by getting history of meaningful use of objects and history of make believe play. Inner language is markedly deficient in an autistic child. Expressive language can be ascertained by asking for extent of vocalization and babbling. It may be pointed out that babbling is present even in deaf children upto the age of six months though it is reduced or deviant in autism. Parents should be asked as to how the child communicates - with sounds or gestures. If there is any language production, enquiry should be made about the intelligibility, syntax and semantics. A consideration of social context within which communication occurs is also important. Children with DLD and deafness make full use of whatever language they posses or in other words language is deficient but communication is not. In contrast children with autism do not wish to communicate even if they have some language. In patients with mental retardation the language and social skills are commensurate with the mental age of the patient (Table III). Table II__Trigger Questions • How does he/she communicate his/her needs? Table III__Features of Common Causes of Delayed Speech
The physician should also enquire regarding previous otitis media or CNS infections. Family history of delayed speech is often present in children with DLD. Some children with DLD are so stressed by language demands that their behavior may simulate primary behavior or emotional disorder. Given the high frequency of behavioral problems in children with speech and language impairment, the history of behavioral problems should be sought. Physical examination should include physical parameters of growth_weight, height and head circumference and complete general and systemic examination. The cutaneous stigmata of tuberous sclerosis should be looked for. External ear anomalies indicate possibility of under- lying hearing impairment. A complete neurological examination with particular attention to movements of tongue, lips and soft palate is mandatory. The child should be asked to imitate movements of the lips, and tongue. Presence of soft neurological signs such as left-right discrimination, fine motor clumsiness and oculomotor disorders are often seen in conjunction with DLD(12). Assessment of hearing by clinical examination is not reliable. This has to be supplemented with audiological evaluation. Hearing assessment is mandatory and should be done inspite of the fact that child appears to have intact hearing. Children with hearing loss may be able to hear environmental sounds and yet may have a loss of hearing in critical speech frequencies. Observation of play with age appropriate fami-liar toys is useful in assessing the child's inner language as well as emotional and behavioral development. Examination of communication skills of the child is perhaps the most difficult part of examination. A doctor is generally a frightening figure to a young child and a routine visit is unlikely to elicit response from the child. Making opportunistic observations in a quiet room when the child is communicating with parents or playing with a familiar object is the best way of assessment. Non-verbal activities such as pushing a toy car or using a pencil and paper are relatively easy to start with. Once a friendly relationship is built, the doctor may be able to elicit more information. Identification of body parts or pointing to familiar objects in the room or a picture book can give clue to comrepehension of language. The doctor can then ask a child to repeat a spoken sentence. This will give clue to nature of speech, it's rhythm and fluency. The child's behavior, his frustration or lack of interest, the span of auditory/visual attention and non-verbal signals are other important aspects of informal assessment. Distinction needs to be made between children who are unable to imitate and produce specific sounds (articulatory) and those despite being able to produce sounds make inconsistent errors of substitution and omission in speech (phonological). The evaluation often requires repeated visits since one may not be able to assess the child in one visit. Informal assessment by the Pediatrician in his clinic is often valuable. However, it should be supplemented by objective analysis of the child's abilities by standardized testing. Clinical Linguistic and Auditory Milestone Scale_a questionnaire that evaluates language development based on parental report is widely used in many centers(13). Use of a standardized scale is a more systematic and objective method of assessment. Children with DLD may not test normal on measures which assess verbal skills (Stanford Binet Test) but are normal on measures which assess non-verbal intelligence. This discrepancy between intelligence and language is important to make the diagnosis of DLD. Investigations How far the clinician proceeds with further investigations depends on the clinical diagnosis and the age of the child. Assessment of hearing is crucial and should be done inspite of the fact that child appears to have intact hearing. Formal psychological assessement is necessary to supplement neurological examination even in cases of apparently significant cognitive deficits. Neuropsychological evaluation indicates the abilities of the child in verbal, visuospatial and cognitive domains and helps in therapy. In a male child with autism or mental retardation genetic test for fragile X should be done. An EEG is appropriate to exclude subclinical seizures in children with isolated language disorder and in cases of acquired aphasia(7). EEG abnormalities are frequently seen in children with autism(14). Patients with other associated neurological deficits, seizures, micro- or macrocephaly will need evaluation with CT scan or MRI. Pediatricians can usually make a working diagnosis in typical cases by informal assessment. However, further evaluation as to the type of language disorder and management plan for remedial help for the child often requires the help of speech and language pathologist and child psychologist. In cases of severe behavioral problems or autism a consultation from psychiatrist should also be sought. It is also important to remember that these developmental disorders can coexist in a patient. Thus a child with autism or deafness can have associated mental retardation. In patients in whom the diagnosis is not clear the doctor should refrain from giving a label but at the same time insititute remedial therapy and follow the patient closely. Remedial Therapy This will depend on the nature and severity of the disorder and require assessment by a psychologist and speech and language pathologist. The psychologist will assess the child's intelligence, memory, attention as well as learning style. The speech pathologist will assess and institute remedial help in language domain. Family members of children with DLD are taught language stimulation techniques so as to foster language development. In children with severe impairments in receptive skills, visual symbols can be provided for spoken word though in severe cases this too may not be enough. In such cases sign language or use of gestures may be taught to facilitate communication. Prognosis Pure articulation disorders respond to speech therapy very well. Rectifying a problem like conductive hearing loss may result in normal language development. Nevertheless children who suffered recurrent ear disease during the first 3 years of life were found to lag behind from controls in speech and language in a long term study(15). In patients with sensorineural hearing loss, prognosis is variable. Most patients with DLD with the exception of severe verbal dyspraxia and verbal auditory agnosia will learn to speak reasonably well by school age. IQ and associated deficits have been observed to be significant prognostic factors(16). Longitudinal studies have found causal relationship between developmental language disorders and reading disabilities. Preliminary findings suggest that expressive disordered children did not have reading deficits, but did exhibit problems in expressive writing(17). Language is the core of learning. It has been said that a preschool child learns language and the school going child uses the language to learn. A child with language disorder is therefore at disadvantage for learning other non-language tasks also. In patients with autism and mental retardation the ultimate outcome rests on the degree of impairment or deficit in other skills besides language. References 1. McKeith RC, Rutter M. A note on the prevalence of speech and language disorders. In: The Child with Delayed Speech. Clinics in Developmental Medicine no. 43 Eds. Rutter M. Martin J AM. London, SIMP, 1972; pp 48-51. 2. Feldman HM, Holland AL, Kemp SS, Janosky JE. Language development after unilateral brain injury. Brain Lang 1992; 42: 89-102. 3. Nass R. Language development in children with congenital strokes. Pediatr Neurol 1997; 4: 109-116. 4. Molfese DL. Electrophysiological responses obtained during infancy and their relation to later language development: Further findings. In: Advances in Child Neuropsychology. Eds. Tramontana MG, Hooper SR. New York, Springer_Verlag; 1995; pp 1-11. 5. Sturner RA, Howard BJ. Preschool Development: Communicative and motor aspects. Pediatr Rev 1998; 10: 6-16. 6. Hall EN. Developmental language disorders. Sem Pediatr Neurol 1997; 4: 77-85. 7. Nass R. Disorders of speech and language development. In: Principles of Child Neurology. Ed. Berg BO, New York, McGraw Hill, 1996; pp 397-409. 8. Pervasive Developmental Disorders. Diagnostic and Statistical Manual of Mental Disorders, DSM IV, 4th edn. Washington DC, American Psychiatry Association, 1994; pp 65-78. 9. Rapin L, Allen DA. Syndromes in developmetnal dysphasia and adult aphasia. In: Language, Communication and Brain. Ed. Plum F. New York, NY Raven Press, 1988; pp 57-75. 10. Harel S, Greenstein Y, Kramer U, Yifat R, Samuel E, Nevo Y, et al. Clinical characteristics of children referred to a child developmental centre for evaluation of speech, language and communication disorder. Pediatr Neurol 1996; 15: 305-311. 11. Tuchman RF. Acquired epileptiform aphasia. Sem Pediatr Neurol 1997; 4: 93-101. 12. Haynes C, Naidoo S. Children wtih specific speech and language impairment. In: Clinics in Developmental Medicine. London, McKeith Press, 1991; pp 129-205. 13. Capute AJ, Palmer FB, Shapiro BK, Wachtel Rc, Schmidt S, Ross A. Clinical linguistic and auditory milestone scale: Prediction of cognition in infancy. Dev Med Child Neurol 1986; 28: 762-771. 14. Tuchman RF, Rapin J. Regression in pervasive developmental disorder seizures and epileptiform electroencephalographic correlates. Pediatrics 1997; 99: 560-566. 15. Klein JO, Teele DW, Pelton SI. New concepts in otitis media: Results of investigations of the Greater Boston Otitis Media study group. Advances in Pediatr 1992; 39: 127-156. 16. Aram DM, Ekelman BL, Nation JE. Preschoolers with language disorders: 10 years later. J Speech Hear Res 1984; 27: 232-244. 17. Wilson BC. Developmental language disorders. In: Pediatric Behavioral Neurology. Ed. Frank Y. New York, CRC Press, 1996; pp 1-33 |
