Asperger syndrome history and symptoms: Difference between revisions
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== Diagnostic Criteria == | == Diagnostic Criteria == | ||
DSM-5 Diagnostic Criteria for Autism Spectrum Disorder (ASD) include all of the following: | DSM-5 Diagnostic Criteria for Autism Spectrum Disorder (ASD) include all of the following:<ref>{{cite book | title = Diagnostic and statistical manual of mental disorders : DSM-5 | publisher = American Psychiatric Association | location = Washington, D.C | year = 2013 | isbn = 0890425558 }}</ref> | ||
A. Persistent deficits in social communication and social interaction across multiple contexts,as manifested by the following, currently or by history: | A. Persistent deficits in social communication and social interaction across multiple contexts,as manifested by the following, currently or by history: | ||
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'''AND''' | '''AND''' | ||
E. These disturbances are not better explained by [[intellectual disability]] (intellectual developmental disorder) or global developmental delay. Intellectual disability and autism | E. These disturbances are not better explained by [[intellectual disability]] (intellectual developmental disorder) or global developmental delay. Intellectual disability and autism spectrum disorder frequently co-occur; to make comorbid diagnoses of autism spectrum disorder and intellectual disability, social communication should be below that expected for general developmental level. | ||
spectrum disorder frequently co-occur; to make comorbid diagnoses of autism spectrum disorder and intellectual disability, social communication should be below that expected for general developmental level. | |||
== History and Symptoms == | == History and Symptoms == | ||
Revision as of 12:04, 22 June 2020
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
A pervasive developmental disorder, Asperger's syndrome is distinguished by a pattern of symptoms rather than a single symptom. It is characterized by qualitative impairment in social interaction, by stereotyped and restricted patterns of behavior, activities and interests, and by no clinically significant delay in cognitive development or general delay in language.[1] Intense preoccupation with a narrow subject, one-sided verbosity, restricted prosody, and physical clumsiness are typical of the condition, but are not required for diagnosis.[2]
History and Symptoms
Social interaction
The lack of demonstrated empathy is possibly the most dysfunctional aspect of Asperger syndrome. Individuals with Asperger's syndrome experience difficulties in basic elements of social interaction, which may include a failure to develop friendships or to seek shared enjoyments or achievements with others (for example, showing others objects of interest); a lack of social or emotional reciprocity; and impaired nonverbal behaviors in areas such as eye contact, facial expression, posture, and gesture.[3]
Unlike those with autism, people with AS are not usually withdrawn around others; they approach others, even if awkwardly, for example by engaging in a one-sided, long-winded speech about a favorite topic while being oblivious to the listener's feelings or reactions, such as signs of boredom or haste to leave.[2] This social awkwardness has been called "active but odd".[2] This failure to react appropriately to social interaction may appear as disregard for other people's feelings, and may come across as insensitive.[2] The cognitive ability of children with AS often lets them articulate social norms in a laboratory context,[3] where they may be able to show a theoretical understanding of other people’s emotions; they typically have difficulty acting on this knowledge in fluid, real-life situations, however.[2] People with AS may analyze and distill their observation of social interaction into rigid behavioral guidelines and apply these rules in awkward ways—such as forced eye contact—resulting in demeanor that appears rigid or socially naïve. Childhood desires for companionship can be numbed through a history of failed social encounters.[3]
The hypothesis that individuals with AS are predisposed to violent or criminal behavior has been investigated but is not supported by data.[3][4] More evidence suggests children with AS are victims rather than victimizers.[5]
Restricted and repetitive interests and behavior
People with Asperger syndrome display behavior, interests, and activities that are restricted and repetitive and are sometimes abnormally intense or focused. They may stick to inflexible routines or rituals, move in stereotyped and repetitive ways, or preoccupy themselves with parts of objects.[1]
Pursuit of specific and narrow areas of interest is one of the most striking features of AS.[3] Individuals with AS may collect volumes of detailed information on a relatively narrow topic such as dinosaurs or deep fat fryers, without necessarily having genuine understanding of the broader topic.[3][2] For example, a child might memorize camera model numbers while caring little about photography.[3] This behavior is usually apparent by grade school, typically age 5 or 6 in the United States.[3] Although these special interests may change from time to time, they typically become more unusual and narrowly focused, and often dominate social interaction so much that the entire family may become immersed. Because topics such as dinosaurs often capture the interest of children, this symptom may go unrecognized.[2]
Stereotyped and repetitive motor behaviors are a core part of the diagnosis of AS and other ASDs.[6] They include hand movements such as flapping or twisting, and complex whole-body movements.[1] These are typically repeated in longer bursts and look more voluntary or ritualistic than tics, which are usually faster, less rhythmical and less often symmetrical.[7]
Speech and language
Although individuals with Asperger syndrome acquire language skills without significant general delay and their speech typically lacks significant abnormalities, language acquisition and use is often atypical.[2] Abnormalities include verbosity; abrupt transitions; literal interpretations and miscomprehension of nuance; use of metaphor meaningful only to the speaker; auditory perception deficits; unusually pedantic, formal or idiosyncratic speech; and oddities in loudness, pitch, intonation, prosody, and rhythm.
Three aspects of communication patterns are of clinical interest: poor prosody, tangential and circumstantial speech, and marked verbosity. Although inflection and intonation may be less rigid or monotonic than in autism, people with AS often have a limited range of intonation; speech may be unusually fast, jerky or loud. Speech may convey a sense of incoherence; the conversational style often includes monologues about topics that bore the listener, fails to provide context for comments, or fails to suppress internal thoughts. Individuals with AS may fail to monitor whether the listener is interested or engaged in the conversation. The speaker's conclusion or point may never be made, and attempts by the listener to elaborate on the speech's content or logic, or to shift to related topics, are often unsuccessful.[2]
Children with AS may have an unusually sophisticated vocabulary at a young age and have been colloquially called "little professors", but have difficulty understanding figurative language and tend to use language literally. Children with AS appear to have particular weaknesses in areas of nonliteral language that include humor, irony, and teasing. Although individuals with AS usually understand the cognitive basis of humor they seem to lack understanding of the intent of humor to share enjoyment with others.Despite strong evidence of impaired humor appreciation, there are anecdotal reports of humor in individuals with AS, which challenge theories of humor in AS.[8]
Other
Individuals with Asperger syndrome may have signs or symptoms that are independent of the diagnosis, but can affect the individual or the family. These include differences in perception and problems with motor skills, sleep, and emotions.
Individuals with AS often have excellent auditory and visual perception.[9] Children with ASD often demonstrate enhanced perception of small changes in patterns such as arrangements of objects or well-known images; typically this is domain-specific and involves processing of fine-grained features.[10] Conversely, compared to individuals with HFA, individuals with AS have deficits in some tasks involving visual-spatial perception, auditory perception, or visual memory.[3] Many accounts of individuals with AS and ASD report other unusual sensory and perceptual skills and experiences. They may be unusually sensitive or insensitive to sound, light, touch, texture, taste, smell, pain, temperature, and other stimuli, and they may exhibit synesthesia;[11] these sensory responses are found in other developmental disorders and are not specific to AS or to ASD. There is little support for increased fight-or-flight response or failure of habituation in autism; there is more evidence of decreased responsiveness to sensory stimuli, although several studies show no differences.[12]
Hans Asperger’s initial accounts[3] and other diagnostic schemes[13] include descriptions of physical clumsiness. Children with AS may be delayed in acquiring skills requiring motor dexterity, such as riding a bicycle or opening a jar, and may seem to move awkwardly or feel "uncomfortable in their own skin". They may be poorly coordinated, or have an odd or bouncy gait or posture, poor handwriting, or problems with visual-motor integration.[3][2] They may show problems with proprioception (sensation of body position) on measures of apraxia (motor planning disorder), balance, tandem gait, and finger-thumb apposition. There is no evidence that these motor skills problems differentiate AS from other high-functioning ASDs.[3]
Children with AS are more likely to have sleep problems, including difficulty in falling asleep, frequent nocturnal awakenings, and early morning awakenings.[14][15] AS is also associated with high levels of alexithymia, which is difficulty in identifying and describing one's emotions.[16] Although AS, lower sleep quality, and alexithymia are associated, their causative relationship is unclear.[15]
Overview
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.
Diagnostic Criteria
DSM-5 Diagnostic Criteria for Autism Spectrum Disorder (ASD) include all of the following:[17]
A. Persistent deficits in social communication and social interaction across multiple contexts,as manifested by the following, currently or by history:
- 1. Deficits in social-emotional reciprocity, ranging, for example, from abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, or affect; to failure to initiate or respond to social interactions.
- 2. Deficits in nonverbal communicative behaviors used for social interaction, ranging,for example, from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or deficits in understanding and use of gestures: to a total lack of facial expressions and nonverbal communication.
- 3. Deficits in developing, maintaining, and understanding relationships, ranging, for example, from difficulties adjusting behavior to suit various social contexts; to difficulties in sharing imaginative play or in making friends; to absence of interest in peers. Specify current severity: Severity is based on social communication impairments and restricted, repetitive patterns of behavior.
AND
B. Restricted, repetitive patterns of behavior, interests, or activities, as manifested by at least two of the following, currently or by history (examples are illustrative, not exhaustive:
- 1. Stereotyped or repetitive motor movements, use of objects, or speech (e.g., simple motor stereotypies, lining up toys or flipping objects, echolalia, idiosyncratic phrases).
- 2. Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior (e.g., extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, need to take same route or eat same food every day).
- 3. Highly restricted, fixated interests that are abnormal in intensity or focus (e.g.,strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interests).
- 4. Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects ofthe environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects,visual fascination with lights or movement).
- Specify current severity:Severity is based on social communication impairments and restricted, repetitive patterns of behavior.
AND
C. Symptoms must be present in the early developmental period (but may not become fully manifest until social demands exceed limited capacities, or may be masked by learned strategies in later life).
AND
D. Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning.
AND
E. These disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay. Intellectual disability and autism spectrum disorder frequently co-occur; to make comorbid diagnoses of autism spectrum disorder and intellectual disability, social communication should be below that expected for general developmental level.
History and Symptoms
Some major neuropsychological abnormalities in patients with Asperger Syndrome (AS) are:[18]
- Difficulty in passing theory of mind tasks
- Executive dysfunction
- Tendency to interpret visual stimuli in parts rather than wholes (poor central coherence)
- There are studies that suggest in patients with AS there is a Verbal IQ (VIQ) > Poor Performance IQ (PIQ) profile which shows strength on verbal skills relative to visuospatial skills and non-verbal problem solving (nonverbal learning disability)[19]
Social interaction and communication
- They usually fail to build friendships due to their odd or lack of social communication skills.[20]
- They have interest in to play or interact with others and social communication but find themselves isolated.[20][21]
- They do not realize that relationships and friendships are based on common interests and flexibility.[20]
- They often make formal communications with others and make one-sided speech and monologues about a specific topic regardless of other people's interest.[2][18][21]
- They are verbal about a certain topic, but can not express feelings or recognize the feelings of others.[22]
- They do not understand social and conversational rules.[21]
- Children with AS are usually victims of bullying at school.[23]
Restricted and repetitive behaviors and interests
- Repetitive, limited and circumscribed interests[24][20]
- Extensive factual information about circumscribed topics (e.g., snakes, names of stars, dinosaurs, computers, train engine numbers)[24][25]
- These symptoms might not be recognized because some topics and interests like dinosaurs are common among children.[25]
- These interests may immerse the family and disrupt family activities.[25][24]
- Patients with autism spectrum disorder (ASD) usually have stereotyped and repetitive motor behaviors and speech such as lining up toys, flipping objects or echolalia.[4]
- Atypical behaviors such as peculiar mannerisms, unusual attachments to objects, obsessions, compulsions, self-injurious behaviors, and stereotypes.[22]
- Stereotypes are repetitive and atypical behaviors such as hand flapping, finger movements, rocking, or twirling, finger flicking, unusual eye gazing, habitual toe walking, and/or persistent sniffing and licking of nonfood items.[22]
- The have unusual attachments for hard items; for example, ballpoint pens, flashlight, keys, action figures.[22]
Language and Speech
- Language is usually adequate or even precocious.[21] Although mild language delay has been reported in AS.[26]
- Atypical language development.[22]
- Usually there is difficulty in communicative use of language:
- Pauses may be due to difficulty in answering questions and structuring their discourse.[18]
Motor Functions and Sensory System
- Delay in acquiring motor skills such as catching a ball and opening jars.[2]
- Difficulty in fine motor skills such as writing, drawing and tying laces. [20]
- Poor coordination, bouncy gait patterns and odd posture and awkwardness.[2]
- Clumsiness[20]
- Problems with sensory impairments may affect movement performance by causing problems in motor planning.[27]
- Hyporsensitivity[20]
- Lower pain thresholds (injuries going unnoticed and becoming infected)
- Indifference to temperature (wearing a t-shirt in winter)
- Vestibular symptoms (rocking or circular movements).
- Hpersensitivity[20]
- Hearing (e.g. noisy environments, vacuum-cleaning),
- Taste (food selectivity)
- Touch (strongly reacting to the contact of certain types of clothing)
- Smell (body odour)
Play Skills
- Problems in pretend play skills with persistent sensory-motor play stage.[22]
- Preference to play with common objects (string, rocks, or sticks).[22]
- The nature of play is usually constructive (puzzles, computer games, and blocks), ritualistic (lining objects up or sorting/matching shapes or colors) or sensory-motor (mouthing, banging, twirling).[22]
Other
- Usually have relative good auditory and verbal skills.[2]
- Deficits in visual-motor and visual-perceptual skills[2]
- Deficits in conceptual learning[2]
- Alexithymia (difficulty in identifying and describing one's emotions).[28]
- Asperger Syndrome (AS) is associated with several conditions which include:
- Attention deficit hyperactivity disorder (ADHD) (most common in pediatric patients) [29]
- Depression (most common in adolescent and adult patients)[29][30]
- Bipolar disorder[29][30]
- Tourette Syndrome[29]
- Obsessive compulsive disorder (OCD)[29][30]
- Tic disorder[29]
- Anxiety disorders[30]
- Schizophrenia[31]
- Nonverbal learning disability[32]
- Difficulty in falling asleep, sleepiness after awakening and during daytime and poor sleep quality[28]
- There have been case-reports of Asperger Syndrome (AS) associated with aminoaciduria,[33] ligamentous laxity[34] and recurrent hypersomnia[35].
References
- ↑ 1.0 1.1 1.2 American Psychiatric Association (2000). "Diagnostic criteria for 299.80 Asperger's Disorder (AD)". Diagnostic and Statistical Manual of Mental Disorders (4th ed., text revision (DSM-IV-TR) ed.). ISBN 0-89042-025-4. Retrieved 2007-06-28.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 Klin A (2006). "Autism and Asperger syndrome: an overview". Rev Bras Psiquiatr. 28 (suppl 1): S3–S11. doi:10.1590/S1516-44462006000500002. PMID 16791390.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 McPartland J, Klin A (2006). "Asperger's syndrome". Adolesc Med Clin. 17 (3): 771–88. doi:10.1016/j.admecli.2006.06.010. PMID 17030291. Unknown parameter
|doi_brokendate=ignored (help) - ↑ 4.0 4.1 Allen D, Evans C, Hider A, Hawkins S, Peckett H, Morgan H (2008). "Offending behaviour in adults with Asperger syndrome". J Autism Dev Disord. 38 (4): 748–58. doi:10.1007/s10803-007-0442-9. PMID 17805955.
- ↑ Tsatsanis KD (2003). "Outcome research in Asperger syndrome and autism". Child Adolesc Psychiatr Clin N Am. 12 (1): 47–63. doi:10.1016/S1056-4993(02)00056-1. PMID 12512398.
- ↑ South M, Ozonoff S, McMahon WM (2005). "Repetitive behavior profiles in Asperger syndrome and high-functioning autism". J Autism Dev Disord. 35 (2): 145–58. doi:10.1007/s10803-004-1992-8. PMID 15909401.
- ↑ Rapin I (2001). "Autism spectrum disorders: relevance to Tourette syndrome". Adv Neurol. 85: 89–101. PMID 11530449.
- ↑ Lyons V, Fitzgerald M (2004). "Humor in autism and Asperger syndrome". J Autism Dev Disord. 34 (5): 521–31. doi:10.1007/s10803-004-2547-8. PMID 15628606.
- ↑ Frith U (2004). "Emanuel Miller lecture: confusions and controversies about Asperger syndrome". J Child Psychol Psychiatry. 45 (4): 672–86. doi:10.1111/j.1469-7610.2004.00262.x. PMID 15056300.
- ↑ Prior M, Ozonoff S (2007). "Psychological factors in autism". In Volkmar FR. Autism and Pervasive Developmental Disorders (2nd ed ed.). Cambridge University Press. pp. 69–128. ISBN 0-521-54957-4.
- ↑ Bogdashina O (2003). Sensory Perceptional Issues in Autism and Asperger Syndrome: Different Sensory Experiences, Different Perceptual Worlds. Jessica Kingsley. ISBN 1-843101-66-1.
- ↑ Rogers SJ, Ozonoff S (2005). "Annotation: what do we know about sensory dysfunction in autism? A critical review of the empirical evidence". J Child Psychol Psychiatry. 46 (12): 1255–68. doi:10.1111/j.1469-7610.2005.01431.x. PMID 16313426.
- ↑ Ehlers S, Gillberg C (1993). "The epidemiology of Asperger's syndrome. A total population study". J Child Psychol Psychiat. 34 (8): 1327–50. doi:10.1111/j.1469-7610.1993.tb02094.x. PMID 8294522.
- ↑ Polimeni MA, Richdale AL, Francis AJ (2005). "A survey of sleep problems in autism, Asperger's disorder and typically developing children". J Intellect Disabil Res. 49 (4): 260–8. doi:10.1111/j.1365-2788.2005.00642.x. PMID 15816813.
- ↑ 15.0 15.1 Tani P, Lindberg N, Joukamaa M; et al. (2004). "Asperger syndrome, alexithymia and perception of sleep". Neuropsychobiology. 49 (2): 64–70. doi:10.1159/000076412. PMID 14981336.
- ↑ Alexithymia and AS:
- Fitzgerald M, Bellgrove MA (2006). "The overlap between alexithymia and Asperger's syndrome". J Autism Dev Disord. 36 (4): 573–6. doi:10.1007/s10803-006-0096-z. PMID 16755385.
- Hill E, Berthoz S (2006). "Response". J Autism Dev Disord. 36 (8): 1143–5. doi:10.1007/s10803-006-0287-7. PMID 17080269.
- Lombardo MV, Barnes JL, Wheelwright SJ, Baron-Cohen S (2007). "Self-referential cognition and empathy in autism". PLoS ONE. 2 (9): e883. doi:10.1371/journal.pone.0000883. PMID 17849012.
- ↑ Diagnostic and statistical manual of mental disorders : DSM-5. Washington, D.C: American Psychiatric Association. 2013. ISBN 0890425558.
- ↑ 18.0 18.1 18.2 Woodbury-Smith MR, Volkmar FR (2009). "Asperger syndrome". Eur Child Adolesc Psychiatry. 18 (1): 2–11. doi:10.1007/s00787-008-0701-0. PMID 18563474.
- ↑ Lincoln, Alan; Courchesne, Eric; Allen, Mark; Hanson, Ellen; Ene, Michaela (1998). "Neurobiology of Asperger Syndrome": 145–163. doi:10.1007/978-1-4615-5369-4_8.
- ↑ 20.0 20.1 20.2 20.3 20.4 20.5 20.6 20.7 Mirkovic B, Gérardin P (2019). "Asperger's syndrome: What to consider?". Encephale. 45 (2): 169–174. doi:10.1016/j.encep.2018.11.005. PMID 30736970.
- ↑ 21.0 21.1 21.2 21.3 21.4 21.5 21.6 Klin A, Pauls D, Schultz R, Volkmar F (2005). "Three diagnostic approaches to Asperger syndrome: implications for research". J Autism Dev Disord. 35 (2): 221–34. doi:10.1007/s10803-004-2001-y. PMID 15909408.
- ↑ 22.0 22.1 22.2 22.3 22.4 22.5 22.6 22.7 22.8 22.9 Johnson CP, Myers SM, American Academy of Pediatrics Council on Children With Disabilities (2007). "Identification and evaluation of children with autism spectrum disorders". Pediatrics. 120 (5): 1183–215. doi:10.1542/peds.2007-2361. PMID 17967920.
- ↑ 23.0 23.1 Zablotsky B, Bradshaw CP, Anderson CM, Law P (2014). "Risk factors for bullying among children with autism spectrum disorders". Autism. 18 (4): 419–27. doi:10.1177/1362361313477920. PMID 23901152.
- ↑ 24.0 24.1 24.2 South M, Ozonoff S, McMahon WM (2005). "Repetitive behavior profiles in Asperger syndrome and high-functioning autism". J Autism Dev Disord. 35 (2): 145–58. doi:10.1007/s10803-004-1992-8. PMID 15909401.
- ↑ 25.0 25.1 25.2 Klin A (2006). "[Autism and Asperger syndrome: an overview]". Braz J Psychiatry. 28 Suppl 1: S3–11. doi:10.1590/s1516-44462006000500002. PMID 16791390.
- ↑ de Giambattista C, Ventura P, Trerotoli P, Margari M, Palumbi R, Margari L (2019). "Subtyping the Autism Spectrum Disorder: Comparison of Children with High Functioning Autism and Asperger Syndrome". J Autism Dev Disord. 49 (1): 138–150. doi:10.1007/s10803-018-3689-4. PMC 6331497. PMID 30043350.
- ↑ Siaperas P, Ring HA, McAllister CJ, Henderson S, Barnett A, Watson P; et al. (2012). "Atypical movement performance and sensory integration in Asperger's syndrome". J Autism Dev Disord. 42 (5): 718–25. doi:10.1007/s10803-011-1301-2. PMID 21643861.
- ↑ 28.0 28.1 Tani P, Lindberg N, Joukamaa M, Nieminen-von Wendt T, von Wendt L, Appelberg B; et al. (2004). "Asperger syndrome, alexithymia and perception of sleep". Neuropsychobiology. 49 (2): 64–70. doi:10.1159/000076412. PMID 14981336.
- ↑ 29.0 29.1 29.2 29.3 29.4 29.5 Ghaziuddin M, Weidmer-Mikhail E, Ghaziuddin N (1998). "Comorbidity of Asperger syndrome: a preliminary report". J Intellect Disabil Res. 42 ( Pt 4): 279–83. doi:10.1111/j.1365-2788.1998.tb01647.x. PMID 9786442.
- ↑ 30.0 30.1 30.2 30.3 Lugnegård T, Hallerbäck MU, Gillberg C (2011). "Psychiatric comorbidity in young adults with a clinical diagnosis of Asperger syndrome". Res Dev Disabil. 32 (5): 1910–7. doi:10.1016/j.ridd.2011.03.025. PMID 21515028.
- ↑ Marinopoulou M, Lugnegård T, Hallerbäck MU, Gillberg C, Billstedt E (2016). "Asperger Syndrome and Schizophrenia: A Comparative Neuropsychological Study". J Autism Dev Disord. 46 (7): 2292–304. doi:10.1007/s10803-016-2758-9. PMID 26936160.
- ↑ Cederlund M, Gillberg C (2004). "One hundred males with Asperger syndrome: a clinical study of background and associated factors". Dev Med Child Neurol. 46 (10): 652–60. doi:10.1017/s0012162204001100. PMID 15473168.
- ↑ Miles SW, Capelle P (1987). "Asperger's syndrome and aminoaciduria: a case example". Br J Psychiatry. 150: 397–400. doi:10.1192/bjp.150.3.397. PMID 3664113.
- ↑ Tantam D, Evered C, Hersov L (1990). "Asperger's syndrome and ligamentous laxity". J Am Acad Child Adolesc Psychiatry. 29 (6): 892–6. doi:10.1097/00004583-199011000-00008. PMID 2273016.
- ↑ Berthier ML, Santamaria J, Encabo H, Tolosa ES (1992). "Recurrent hypersomnia in two adolescent males with Asperger's syndrome". J Am Acad Child Adolesc Psychiatry. 31 (4): 735–8. doi:10.1097/00004583-199207000-00023. PMID 1644738.