PERVASIVE DEVELOPMENTAL DISORDERS

Introduction:Pervasive developmental disorders include several that are characterized by impaired reciprocal social interactions, aberrant language development, and restricted behavioral repertoire. Pervasive developmental disorders typically emerge in young children before the age of 3 years, and parents often become concerned occur as expected. In about 25 percent of cases, some language develops and is subsequently lost. Some children with pervasive developmental disorders are not identified with problems until school age, because they make relatively few demands and have minimal conflicts with others owning to their infrequent social engagement. Children with pervasive developmental disorders often exhibit idiosyncratic intense interest in a narrow range of activities, resist change, and are not appropriate responsive to the social environment. These disorders affect multiple areas of development, are manifested early in life, and cause persistent dysfunction.

Autistic Disorder:Autistic disorder (historically called early infantile autism, childhood autism, or Kanner’s autism) is characterized by symptoms from each of the following three categories: qualitative impairment in social interaction, impairment in communication, and restricted repetitive and stereotyped patterns of behavior or interests.

Epidemiology:Prevalence. Autistic disorder is believed to occur at a rate of about 8 cases per 10,000 children (0.8 percent). Multiple epidemiologic surveys mainly in Europe have resulted in variable rates of autistic disorder ranging from 2 to 30 cases per 10,000. By definition, the onset of autistic disorder is before the age of 3 years, although in some cases, it is not recognized until a child is much older.

Sex distribution:Autistic disorder is four to five times more frequent in boys than in girls. Girls with autistic disorder are more likely to have more severe mental retardation.

Socioeconomic Status:Early studies suggested that a high socioeconomic status was more common in families with autistic children; however , these findings were probably based on referral bias. Over the past 25 years, no epidemiological studies have demonstrated an association between autistic disorder and any socioeconomic status.

Etiology and Pathogenesis:Genetic Factors. Current evidence supports a genetic basis for the development of autistic disorder in most cases, with a contribution of up to four or five gene. Family studies have demonstrated a 50 to 200 times increase in the rate of autism in siblings of an index child with autistic disorder. Additionally, even when not affected with autism, siblings are at increased risk for a variety of developmental disorders often related to communication and social skills.

Biological FactorsThe high rate of mental retardation among children with autistic disorder and the higher-than-expected rates of seizure disorder further support the biological basis for autistic disorder. Approximately 70 percent of children with autistic disorder have mental retardation. About one third of these children have mild to moderate mental retardation, and close to half of these children are severely of profoundly mentally retarded.

Immunological Factors

Several reports have suggested that immulogical imcompatibility (i.e., maternal antibodies directed at the fetus) may contribute to autistic disorder. The lymphocytes of some autistic children react with maternal antibodies, which raises the possibility that embryonic neural or extraembryonic tissues may be damaged during gestation.

Perinatal FactorsA higher-than-expected incidence of perinatal complications seems t occur in infants who are later diagnosed with autistic disorder. Maternal bleeding after the first trimester and meconium in the amniotic fluid have been reported in the histories of autistic children more often than in the general population.

Biochemical FactorsA number of studies in the last few decades have demonstrated that about one third of patients with autistic disorder have high plasma serotonin concentrations. This finding, however, is not specific to autistic disorder, and persons with mental retardation without autistic disorder also display this trait.

Psychosocial and Family FactorsStudies comparing parents of autistic children with parents of normal children have shown no significant differences in child-rearing skills.

DSM-IV-TR Diagnostic Criteria for Autistic Disorder:

A. A total of six (or more) items from (1), (2), and (3), with at least two from (1), and one each from (2) and (3) :(1) Qualitative impairment in social interaction, as manifested by at least two of the following :

(a) marked impairment in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body posture, and gestures to regulate social interaction

(b) failure to develop peer relationships appropriate to developmental level(c) a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g.,

by a lack of showing, bringing, or pointing out objects of interest)(d) lack of social or emotional reciprocity

(2) qualitative impairments in communication as manifested by at least one of the following:(a)delay in , or total lack of , the development of spoken language (not accompanied by an attempt to compensate through alternative modes of communication such as gestures or mime)(b) in individuals with adequate speech, marked impairment in the ability to initiate or sustain a conversation with others(c)stereotyped and repetitive use of language or idiosyncratic language(d)lack of varied, spontaneous make-believe play or social imitative play appropriate to developmental level

(3) restricted repetitive and stereotyped patterns of behavior, interests, and activities , as manifested by at least one of the following: (a)encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus (b) apparently inflexible adherence to specific, nonfunctional routines or rituals (c) stereotyped and repetitive motor mannerism (e.g., hand or finger flapping or twisting , or complex whole-body movements) (d) persistent preoccupation with parts of objectB. Delays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years: (1) social interaction, (2) language as used in social communication, or (3) symbolic or imaginative play.C. The disturbance is not better accounted for by Rett’s disorder or childhood disintegrative disorder.

Differential Diagnosis

Autism must first be differentiated from one of the other pervasive developmental disorders such as Asperser’s disorder and pervasive developmental disorder not otherwise specified . Further, including mental retardation syndromes and developmental language disorders. Other disorders in the differential diagnosis are schizophrenia with childhood onset, congenital deafness or severe hearing disorder, psychosocial deprivation, and disintegrative (regressive) psychoses. It is sometimes difficult to make a diagnosis of autism because it is overlapping of symptoms with childhood schizophrenia, mental retardation syndromes with behavioral symptoms, mixed receptive-expressive language disorder, and hearing disorder.

Procedure for Differential Diagnosis on a Multiaxial System:

1. Determine intellectual level2. Determine level of language development3. Consider whether child’s behavior is appropriate for

(i) chronological age(ii) mental age(iii)language age

4. If not appropriate, consider deferential diagnosis of psychiatric disorder according to(i) pattern of social interaction(ii) pattern of language(iii) pattern of play(iv) other behavior

5. Identify any relevant medical condition6. Consider whether there are any relevant psychosocial factors

Schizophrenia with Childhood Onset

Although a wealth of literature on autistic disorder is available, few data exist on children under age 12 who meet diagnostic criteria for schizophrenia. Schizophrenia is rare in children under the age of 5. It is accompanied by hallucinations or delusions, with a lower incidence of seizures and mental retardation and a more even IQ than autistic children exhibit. Compares autistic disorder and schizophrenia with childhood inset.

Mental Retardation with Behavioral Symptoms

About 40 percent of autistic children are moderately, severely, or profoundly retarded, and retarded children may have behavioral symptoms that include autistic features. When both disorders are present, both should be diagnosed.

Mixed Receptive-Expressive Language Disorder

Some children with mixed receptive –expressive language disorder have mild autistic-like features and may present a diagnostic problem. Procedure for differential diagnosis on a multiaxial system summarizes the major differences between autistic disorder and mixed receptive-expressive language disorder.

Acquired Aphasia with Convulsion

Acquired aphasia with convulsion is a rare condition that is sometimes difficult to differentiate from autistic disorder and childhood disintegrative disorder. Children with the condition are normal for several years before losing both their receptive and their expressive language over a period weeks or months. Most have a few seizures and generalized EGG abnormalities at the onset, but these signs usually do not persist.

Congenital Deafness or Severe Hearing Impairment.

Because autistic children are often mute or show a selective disinterest in spoken language, they are often thought to be deaf. Differentiating factors include the following: Autistic infants may babble only infrequently, whereas deaf infants have a history of relatively normal babbling that then gradually tapers off and may stop at 6 months to 1 year of age.

Course and Prognosis:

Autistic disorder is generally a lifelong disorder with a guarded prognosis. Autistic children with IQs above 70 and those who use communicative language by ages 5 to 7 years tend to have the best prognoses. Recent follow-up data comparing high -IQ autistic children at the age of 5 years with their current symptomatology at age 13 through young adulthood found that a small proportion no longer met criteria for autism, although they still exhibited some features of the disorder. Most demonstrated positive changes in communication and social domains over time.

Treatment:

The goals of treatment for children with autistic disorder are to target behaviors that will improve their abilities to integrate into schools, develop meaningful peer relationships, and increase the likelihood of maintaining independent living as adults. To do this, treatment interventions aim to increase socially acceptable and prosocial behavior, to decrease odd behavioral symptoms, and to improve verbal and nonverbal communication. Both language and academic remediation are often required.

RETT’S DISORDER:

In 1965. Andreas Rett, an Australian physician, identified a syndrome in 22 girls who appeared to have developed normally for at least 6-months followed by devastating developmental deterioration. Rett’s disorder is progressive condition that has its onset after some months of what appears to be normal development. Head circumference is normal a birth and developmental milestone are unmarkable in early life. Between 5 and 48 months of age, generally between 6 months and a year, head growth begins to decelerate.

Etiology :

The cause of Rett’s disorder is unknown, although the progressive deteriorating course after an initial normal period is compatible with a metabolic disorder. In some patients with Rett’s disorder, the presence of hyperammonemia has led to postulation that an enzyme metabolizing ammonia is deficient, but hyperammonemia has not been found in most patients with Rett’s disorder.

DSM-IV-TR Diagnostic Criteria for Rett’s Disorder:

A. All of the following(1) Apparently normal prenatal and perinatal development(2) Apparently normal psychomotor development through the first months after birth(3) Normal head circumference at birth

B. Onset of all of the following after the period of normal development :(1) Deceleration of head growth between ages 5 and 48 months (2) Loss of previously acquired purposely hand skills between ages 5 and 30 months with the subsequent

development of stereotyped hand movements (e.g., hang wringing or hand washing)(3) Loss of social engagement early in the course (although often social interaction develops later )(4) Appearance of poorly coordinated gait or trunk movements(5) Severely impaired expressive and receptive language development with severe psychomotor retardation

Course and Prognosis:

Rett’s disorder is progressive. The prognosis is not fully known, but patients who live into adulthood remain at a cognitive and social level equivalent to that in the first year of life.

Treatment:

Treatment is symptomatic. Physiotheraphy has been beneficial for the muscular dysfunction, and anticonvulsant treatment is usually necessary to control the seizures. Behavior therapy, along with medication, may help control self-injurious behaviors, as it does in the treatment of autistic disorder, and it may help regulate the breathing disorganization.

CHILDHOOD DISINTEGRATIVE DISORDER:

Childhood disintegrative disorder is characterized by marked regression in several areas of functioning after at least 2 years of apparently normal development. Childhood disintegrative disorder, also called Heller’s syndrome and disintegrative psychosis was described in 1908 as a deterioration over several months of intellectual, social, and language function occurring in 3- and 4-years-old with previously normal functions. After the deterioration, the children closely resembled children with autistic disorder.

Epidemiology:

Epidemiological data have been complicated by the variable diagnostic criteria used, but childhood disintegrative disorder is estimated to be at least one tenth as common as autistic disorder, and the prevalence has been estimated to be about 1 case in 100,000 boys. The ratio of boys to girls is estimated to be between 4 and 8 of boys to 1 girl.

Etiology:

The cause of childhood disintegrative disorder is unknown, but it has been associated with other neurological conditions; including seizure disorders, tuberous sclerosis, and various metabolic disorders.

DSM-IV-TR Diagnostic Criteria for Childhood Disintegrative Disorder:

A. Apparently normal development for at least the first 2 years after birth as manifested by the presence of age-appropriate verbal and nonverbal communication, social relationships, play, and adaptive behavior.

B. Clinically significant loss of previously acquired skills (before age 10 years) in at least two of the following areas:(1.) Expressive or receptive language(2.) Social skills or adaptive behavior(3.) Bowel or bladder control(4.) Play(5.) Motor skills

C. Abnormalities of functioning in at least two of the following areas:(1.) qualitative impairment in social interaction (e.g., impairment in nonverbal behaviors, failure to develop peer relationships ,lack of social or emotional reciprocity)(2.) qualitative impairments in communication (e.g., delay or lack of spoken language, inability to initiate or sustain a conversation, stereotyped and repetitive use of language, lack of varied make-believe play)(3.) restricted , repetitive and stereotyped patterns of behavior , interests , and activities, including motor stereotypies and mannerism

D. The disturbance is not better accounted for by another specific pervasive developmental disorder or by schizophrenia.

Course and Prognosis:

The course of childhood disintegrative disorder is variable, with a plateau reached in most cases, a progressive deteriorating course in rare cases, and some improvement in occasional cases to the point of regaining the ability to speak in sentences. Most patients are left with at least moderate mental retardation.

Treatment:

Because of the clinical similarity to autistic disorder, the treatment of childhood disintegrative disorder includes the same components available in the treatment of autistic disorder.

ASPERGER’S DISORDER:

Asperger’s disorder is characterized by impairment and oddity of social interaction and restricted interest and behavior reminiscent of those seen in autistic disorder. Unlike autistic disorder, in Asperger’s disorder no significant delay occur in language, cognitive development, or age-appropriate self-help skills.

Etiology:

The cause of Asperger’s disorder is unknown, but family studies suggest a possible relationship to autistic disorder. The similarity of Asperger’s disorder to autistic disorder supports the presence of genetic, metabolic, infectious, and perinatal contributing factors.

DSM-IV-TR Diagnostic Criteria for Asperger’s Disorder:

A. Qualitative impairment in social interaction, as manifested by at least two of the following :(1) Marked impairment in the use of multiple nonverbal behaviors such as eye-to-eye gaze , facial

expression body postures , and gestures to regulate social interaction(2) Failure to develop peer relationships appropriate to developmental level (3) A lack of spontaneous seeking to share enjoyment, interests, or achievements with other people

(e.g., by a lack of showing , bringing , or pointing out objects of interest to other people )(4) Lack of social or emotional reciprocity

B. Restricted repetitive and stereotyped patterns of behavior, interest, and activities, as manifested by at least one of the following :(1) Encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is

abnormal either in intensity or focus(2) Apparently inflexible adherence to specific , nonfunctional routines or rituals(3) Stereotyped and repetitive motor mannerism (e.g., hand or finger flapping or twisting , or complex

whole-body movements)(4) persistent preoccupation with parts of object

C. The disturbance causes clinically significant impairment in social, occupational, or other important areas of functioning.

D. There is no significant general delay in language (e.g., single words used by age 2 years, communicative phrases used by age 3 years.

E. There is no significant delay in cognitive development or in the development of age-appropriate self-help skills , adaptive behavior (other than in social interaction ) , and curiosity about the environment in childhood

F. Criteria are not met for another specific pervasive developmental disorder or schizophrenia

Courses and Prognosis:

Although little is known about the cohort described by the DSM-IV-TR diagnostic criteria, past case reports have shown variable courses and prognoses for patients who have received diagnoses of Asperger’s Disorder. The factors associated with a good prognosis are a normal IQ and high-level social skills.

Treatment:

Treatment of Asperger’s disorder is supportive, and goals are to promote social behavior and peer relationship. Interventions are initiate with the goal of shaping interactions so that they better match those of peers. Very often children with Asperger’s disorder are highly verbal and have excellent academic achievement. The tendency of children and adolescents with Asperger’s disorder to rely on rigid rules and routines can become a source of difficulty for them and be an area that requires therapeutic intervention.

DSM-IV-TR Diagnostic Criteria for Pervasive Developmental Disorder Not Otherwise Specified:

This category should be used when there is a severe and pervasive impairment in the development of reciprocal social interaction associated with impairment with either verbal or nonverbal communication skills or with the presence of stereotyped behavior, interest and activities, but the criteria are not met for a specific pervasive developmental disorder, schizophrenia, schizotypal personality disorder, or avoidant personality disorder. For example, this category includes “atypical autism”- presentations that do not meet the criteria for autistic disorder because of late age at onset , atypical symptomatology, or subthreshold symptomatology, or all of these

PERVASIVE DEVELOPENTAL DISORDER NOT OTHERWISE SPECIFIED:

The DSM-IV-TR defines disorder not otherwise specified as severe, pervasive impairment in communication skills or the presence of stereotyped behavior, interests, and activities with associated impairment impairment in social interactions. The criteria for a specific pervasive developmental disorder, schizophrenia, a schizotypal and avoidant personality disorders are not met, however. Some children who receive the diagnosis exhibit a markedly restricted repertoire of activities and interest.

Treatment:

The treatment approach is basically the same as in autistic disorder. Mainstreaming in school may be possible. Compared with autistic children, those with pervasive developmental disorder not otherwise specified generally have better candidates for psychotherapy.