The toddler with delayed speech
by Joel D. Lazaro
Toddlers have the powerful skill and drive to produce the sounds of speech and have
the capacity to learn and understand the basic structure of the spoken language
they hear. Some children, however, do not. There are a number of possible causes
and the major considerations are: 1) hearing loss, 2) mental retardation, 3) developmental
language disorder (dysphasia) and 4) autism. Read on to know more about:
1. Overview of normal speech/language pathway
2. Normal milestones in language acquisition
3. Red flags of speech and language problem: when to investigate?
4. Evaluation and management of a tollder with speech delay
Normal Speech / Language Pathway
The perception, comprehension and production of language represent different operations
in the language areas of the brain, taking place sequentially. The normal language
pathway (figure 1) starts with word sounds that is received by the auditory system.
The decoding or perception of these sounds according to the phonologic rules of
the particular language occurs in the auditory and auditory association areas of
the temporal lobe in the cerebral hemisphere dominant for language. Comprehension
and interpretation of the linguistic message will then occur followed by the selection
and retrieval of words from the language processing areas of the brain resulting
in transformation of thoughts and intentions into formulated concepts. The formulated
concepts are then programmed into phonemic sequences that transmit the motor commands
for speech production.
Receptive Language Equally important as expressive language is the receptive language
skills. Newborns respond to vocal stimuli by eye widening or changes in respiration
or sucking rate. At 2-3 months, infants will watch and listen intently as adults
speaks. By 4 months of age the normal infant will turn his head to locate the source
of a voice. By 7-8 months of age, an infant will attend selectively to his own name
when uttered by an adult and at 9 months are able to comprehend the word �no'. Infants
respond to one step command accompanied by gesture from an adult e.g. 'come here'
at 1 year age and will dos o without gestures by 15-18 months. By 2.5 to 3 years,
children will point to objects described by use, e.g. 'point the one we wear on
our fee' and follow simple prepositional commands, e.g. 'put the cup under the table'.
Red Flags of Speech and Language Problem: When
to refer?
Milestones for the acquisition of language vary a great deal from child to child.
This makes it difficult for physicians to decide when the child is outside the norm
and therefore requires specialist evaluation. The toddler who is not talking initially
for example maybe reaching language milestones slowly than the norm (language delay)
or in a disordered or chaotic manner (language disorder or deviancy). The abnormality
in language development may be part of a general developmental lag (global developmental
delay) or occur in isolation, in the context of normal motor or cognitive function
(language dissociation). Finally, a child who spoke normally at one time but is
no longer talking has suffered a loss of language (language regression). Assessing
these possibilities forms the basis of the evaluation of a toddler with speech delay.
There are however RED FLAGS of speech and language problems which serve as good
indicators on when to refer for specialist evaluation.
Red Flags
6 months Does not turn eyes and head to sound
10 months Absent babbling
Does not respond to name
15 months Does not understand and respond to'no' or 'bye-bye'
18 months Does not have any meaningful words beyond mama/papa
Does not point to what he/she wants
2 years old Does not put two words together to form phrases
Does not understand what is said to them without
gesture excessive and inappropriate jargon and echolalia
Does not point to body parts on request
3 years old Use no simple sentences or has not begun to ask questions
Normal Speech and Language Milestones
Language development starts at birth. It consists of symbol system for the storage
and exchange of information (Coplan, 1995). It is described in terms of receptive
language and expressive language ability.
Expressive language
Human infants produce a uniform sequence of pre-linguistic utterances regardless
of the language they are exposed with. The earliest of these utterances is cooing,
which are musical, open vowel sounds, which appears at 4-6 weeks of life. This is
followed in a few months by bilabial sounds as if the child is blowing bubbles.
By 5 months, the child is already laughing and a variety of monosyllables appear
e.g. 'ba', 'ma', 'pa'. Between 6 to 8 months, infants produce polysyllabic babbling,
which consists of syllable repeated over and over: 'lalalalala', 'dadadadada' and
so forth. By 9-10 months infants will spontaneously utter the word 'mama' or 'papa'
to label the parent. By 12 months, the infant has acquired one or two words other
than mama/papa. Vocabulary growth accelerates during the 2 nd year of life starting
at one new word per week at 12 months and attaining a rate of one or more new words
per day by 2 years of age. A typical 2 year old toddler has a vocabulary of at least
50 words and should be producing 2 word phrases. Vocabulary growth continues to
accelerate during the 3 rd year, ultimately reaching a rate of several new words
per day. Children at age 3 years will have a vocabulary that is too many to count
and develop 'telegraphic' speech composing of 3-5 word sentences containing a subject
and predicate, but lacking in conjunctions, verb or articles. At 4 years old, the
normal child is able to produce grammatically correct sentences.
Evaluation and Management of a Toddler with Speech
Delay
The history and physical examination are important because they may provide information
regarding the etiology of the child's disorder. The history is also crucially important
for clarifying the nature of the child's symptoms. Table 1 shows the typical parental
concerns regarding language problems and the corresponding nature of language disorder.
Table 1 Speech Delay: A Clinical Classification
Symptom Classification: When parents say:
Articulation disorder 'I'm the only one who understands what he says'
Expressive language delay 'He will do what I say, but when he wants something,
he just points'
Global language delay 'He can't play show me your nose and the only word
he says is mama '
Language disorder 'He never made those funny baby sounds or said
Mama and Dada and now he just repeats everything
I say '
Language loss or regression 'He used to say things like Mike go bye-bye but now
he doesn't talk at all'
The physical examination must focus on neurologic examination and search for dysmorphic
features which may characterize genetic syndromes associated with language disorders.
The most revealing aspect of the neurologic examination comes from the mental status,
which includes the child's expressive and receptive language skills, play and behavior
patterns. A complete developmental evaluation is also recommended to evaluate if
the language disorder is an isolated problem or part of a global pattern of delay.
Laboratory examination indicated for a toddler with speech delay include tests to
assess hearing sensitivity. No child is too young or too handicapped to undergo
definitive assessment of hearing. Cooperative children may be tested using behaviourally
reinforced methods such as play audiometry, others may undergo electrophysiologic
testing using Brainstem auditory evoked response (BAER). Electroencephalography
is recommended in the context of a child whose clinical picture shows loss or regression
of language skills. A prolonged sleep EEG to rule out unsuspected epileptiform activity
is warranted in this situation to rule out acquired epileptic aphasia or Landau-Kleffner
syndrome. Clinicians may choose to validate their clinical impression by using language
checklists, such as Early Language Milestones (ELM) (Coplan, 1989) or the Clinical
Linguistic and Auditory Milestone Scale (CLAMS) (Capute, 1986) which helps in deciding
whether language is developing normally or not. If a detailed and/or more quantitative
evaluation of the child's speech/language disorder is required, he should be referred
to a speech and language pathologist. For those neuropsychological testing is recommended.
The key to the successful management of a toddler with speech delay depends on the
correct developmental diagnosis. Specific cause of speech delay necessitates specific
intervention approach. Management of a child with speech delay encompasses may disciplines
and a coordinated effort is necessary for maximal benefit. The primary aim of intervention
is to provide the child with means to communicate effectively through whatever channel
is appropriate at the time. Early identification and appropriate intervention will
maximize the child's potential in life.
REFERENCES
Coplan, J. 1995. Normal Speech and Language Development: An Overview Pediatrics
in Review, Vol. 16 No. 3
Coplan, J. 1989. ELM Scale: the Early Language Milestone Scale. Austin, TX: Pro-Ed
Capute, A. 1986. Clinical Linguistic and Auditory Milestone Scale. Dev. Med. And
Child Neurology, Vol. 28, 762-771