Asperger syndrome overview

# Overview
Autism Spectrum Disorder (ASD) is a category of neurodevelopmental disorders with problems in social communication/interaction and restricted and repetitive behaviors/interests. According to the Diagnostic And Statistical Manual Of Mental Disorders, Fifth Edition (DSM-5) released by the American Psychiatric Association (APA) in 2013, Asperger Syndrome (AS) goes under a spectrum of disorders called 'Autism Spectrum Disorder (ASD)'. Asperger Syndrome is named after Hans Asperger, an Austrian physician. He was the first to describe and separate Asperger Syndrome from autism and called it 'autistic psychopathy' which later became known as Asperger Syndrome.

# Historical Perspective
Asperger Syndrome (AS) is believed to be first described as autistic psychopathy in German by Hans Asperger. He distinguished his cases from autism which later became known as 'Asperger's Syndrome'. In 1981, Lorna Wing published Aspergers works in English.  In 1994, DSM-4 classified Asperger Syndrome (AS) as a subtype in the category of pervasive developmental disorders (PDD). In 2013, DSM-5 combined 4 of  the 5 subtypes of pervasive developmental disorders (PDD) under the Autism Spectrum Disorder (ASD) category.

# Classification
According to the Diagnostic And Statistical Manual Of Mental Disorders, Fifth Edition (DSM-5) released by the American Psychiatric Association (APA) in 2013, Asperger Syndrome (AS) is in the Autism Spectrum Disorder (ASD) category. Autism Spectrum Disorder (ASD) is a category of neurodevelopmental disorders in DSM-5 with problems in social communication/interaction, restricted and repetitive behaviors/interests.

# Pathophysiology
The exact pathophysiology of Asperger Syndrome is unknown, however some neuroimaging and neuropsychological studies have reported some findings.

# Causes
The exact cause of Asperger (AS) is unknown. Many factors including genetics, family history of autism spectrum disorders (ASD) and enviornmental factors such as older parental age, prematurity, low birth weight and pregnancy complications have been associated with autism spectrum disorder (ASD).

# Epidemiology and Demographics
Prevalence rates for Asperger Syndrome ranges from 0.03 to 4.84 per 1,000 in different studies. In 2014, the overall prevalence of autism spectrum disorders (ASD) was estimated to be 16.8 per 1,000 children aged 8 years. The male to female prevalence ratio for ASD is approximately 4 to 1. The estimate for ASD prevalence was 7% and 22% higher among white children compared to black and Hispanic children respectively.

# Risk factors
Several risk factors associated with Asperger Syndrome (AS) and austim spectrum disorder (ASD) are: male gender, older parental age, family history of austim spectrum disorder (ASD), prematurity, low birth weight and pregnancy complications.

# Screening
Screening instruments for Asperger Syndrome include: Autism Screening Questionnaire (ASQ), Autism Spectrum Quotient (AQ), Autism Spectrum Screening uestionnaire (ASSQ) and diagnostic instruments for Asperger Syndrome include: Asperger Syndrome Diagnostic Scale (ASDS), Gilliam Aspergers Disorder Scale (GADS) and Asperger Syndrome (and high-functioning autism) Diagnostic Interview (ASDI).

# Natural history, complications and prognosis
It is believed that 20% of Asperger Syndrome patients 'grow out of their disorder and and do not meet the diagnostic criteria as adults, whereas many other patients improve. Diagnosis of AS is often delayed and sometimes done in adulthood. Social impairment is lifelong. Early diagnosis and intervention in patients with AS may improve adaptation and adjustment of the child. Asperger Syndrome (AS) is associated with several conditions such as attention deficit hyperactivity disorder (ADHD) (most common in pediatric patients), depression (most common in adolescent and adult patients) and anxiety disorders.

# Diagnosis

## Diagnostic Criteria
The Diagnostic Criteria for Autism Spectrum Disorder (ASD) released by the American Psychiatric Associations Diagnostic and Statistical Manual, Fifth Edition (DSM-5) is used for the diagnosis of Asperger Syndrome (AS).

## History and Symptoms
Several symptoms may be seen in Asperger Syndrome (AS) with impairments in social interaction, communication and restricted, repetitive behaviors and  interests being the most important. There may be impairments in motor and sensory functions, speech, language and.sleep.

## Physical examination
The most common clinical signs in Asperger Syndrome (AS) are impairments in social communication and repetitive behaviors.

## Laboratory findings
Routine laboratory testing is not recommended.

## Other diagnostic studies
Routine neuroimaging, electroencephalography (EEG) and genetic testing are not recommended in patients with Asperger Syndrome (AS).

# Treatment

## Medical therapy
Medical treatments used in Asperger Syndrome include: stimulants, a-2 adrenergic agonists, atypical antipsychotics, antidepressants and anticonvulsants. Many studies believe that medications alone can not improve Asperger Syndrome's (AS) symptoms and other complementary interventions (social and behavioral) are required.

## Behavioral Therapy
Behavioral therapies in Asperger Syndrome (AS) are used to help the patients with their social communication and to develop social skills.

## Cost-effectiveness of therapy
Based on a prevalence of 1.1 % for autism spectrum disorder (ASD) in the US, the economic burden for ASD has been estimated to be $268.2991 billion (1.467% of GDP) and $460.8002 billion (1.649% of GDP) in 2015 and 2025 respectively.

## Future or investigational therapies
There have been some experimental therapy and suggestions such as oxytocin and treatment with stem cells in patients with Asperger Syndrome (AS).