# 238 - 6E60 Secondary neurodevelopmental syndrome

# 6E60 Secondary neurodevelopmental syndrome

Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders
Secondary obsessive-compulsive or related syndrome
Secondary dissociative syndrome
Secondary impulse control syndrome
Secondary neurocognitive syndrome
Secondary personality change
Secondary catatonia syndrome
Other specified secondary mental or behavioural syndrome
Secondary mental or behavioural syndrome, unspecified.
Secondary neurodevelopmental syndrome
Secondary neurodevelopmental syndromes involve significant neurodevelopmental features that 
do not fulfil the diagnostic requirements of any of the specific neurodevelopmental disorders 
that are judged to be a direct pathophysiological consequence of a medical condition not 
classified under mental and behavioural disorders, based on evidence from the history, physical 
examination or laboratory findings. The appropriate diagnostic subcategory (see below) should 
be used depending on whether the difficulties are related to speech or language functions or to 
other areas.
Secondary speech or language syndrome
Essential (required) features
• The presence of significant difficulties in the acquisition and execution of specific speech 
or language functions (e.g. errors of pronunciation, articulation or phonology), that arise 
during the developmental period and persist substantially beyond the expected age, is 
required for diagnosis.
• The symptoms are judged to be the direct pathophysiological consequence of a medical 
condition with onset during the prenatal or developmental period, based on evidence 
from history, physical examination or laboratory findings. This judgement depends on 
establishing the following.
• The medical condition is known to be capable of producing the symptoms.
• The course of developmental difficulties (e.g. onset, remission, response of the 
neurodevelopmental symptoms to treatment of the etiological medical condition) is 
consistent with causation by the medical condition.
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Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere

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Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere
• The symptoms are not better accounted for by a primary neurodevelopmental disorder (e.g. 
a developmental speech and language disorder, a disorder of intellectual development).
• The symptoms are a specific focus of clinical attention.
Boundaries with other disorders and conditions (differential diagnosis)
Boundary with developmental speech and language disorders
In developmental speech and language disorders (e.g. developmental speech sound disorder, 
developmental speech fluency disorder, developmental language disorder), the individual’s ability 
to understand or produce speech and language or to use language in context for the purposes 
of communication is markedly below what would be expected given the individual’s age and 
level of intellectual functioning. However, if the symptoms meet the diagnostic requirements of 
developmental speech and language disorders and are judged to be the direct pathophysiological 
consequence of a medical condition with onset during the prenatal or developmental period, a 
diagnosis of secondary speech or language syndrome should be assigned instead.
Boundary with disorders of intellectual development
Individuals with a disorder of intellectual development may exhibit impaired speech production. 
If speech production difficulties require separate clinical attention in the context of a disorder of 
intellectual development that is judged to be due to a medical condition, an additional diagnosis 
of a secondary speech or language syndrome may be assigned.
Boundary with selective mutism
Selective mutism is characterized by consistent selectivity in speaking, such that a child 
demonstrates adequate speech production in specific situations (typically at home), but 
predictably fails to speak in others (typically at school). Selective mutism can occur in the presence 
of secondary speech or language syndrome, and both diagnoses may be assigned if warranted.
Potentially explanatory medical conditions (examples)
Brain disorders and general medical conditions that have been shown to be capable of producing 
speech or language syndromes include:
• diseases of the nervous system (e.g. brain injury, cerebral palsy, encephalopathy, epilepsy 
or seizures, myasthenia gravis, stroke);
• certain infectious or parasitic diseases (e.g. encephalitis, meningitis);
• developmental anomalies (e.g. Joubert syndrome, cleft palate, deafness);
• injury, poisoning or certain other consequences of external causes (e.g. brain injury, 
concussion, traumatic haemorrhage).
Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere

Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders
Other specified secondary neurodevelopmental syndrome
Essential (required) features
Note: presentations that meet the diagnostic requirements of disorders of intellectual 
development, autism spectrum disorder or stereotyped movement disorder and are judged to be 
the direct pathophysiological consequence of a medical condition are not diagnosed as secondary 
neurodevelopmental syndrome because, by convention, these conditions are diagnosed regardless 
of whether or not they are caused by a medical condition classified elsewhere.
• The presence of significant difficulties arising during the developmental period in the 
acquisition and execution of specific intellectual, motor coordination or social functions 
that do not fulfil the diagnostic requirements of disorders of intellectual development, 
autism spectrum disorder or stereotyped movement disorder, and that persist substantially 
beyond the expected age, is required for diagnosis.
• The symptoms are judged to be the direct pathophysiological consequence of a medical 
condition with onset during the developmental period, based on evidence from history, 
physical examination or laboratory findings. This judgement depends on establishing 
the following.
• The medical condition is known to be capable of producing the symptoms.
• The course of developmental difficulties (e.g. onset, remission, response of the 
neurodevelopmental symptoms to treatment of the etiological medical condition) is 
consistent with causation by the medical condition.
• The symptoms are not better accounted for by a neurodevelopmental disorder (e.g. a 
disorder of intellectual development, autism spectrum disorder, developmental motor 
coordination disorder) or the effects of a medication or substance.
• The symptoms are a specific focus of clinical attention.
Boundaries with other disorders and conditions (differential diagnosis)
Boundary with dementia with onset during the developmental period
Difficulties in the acquisition or execution of specific intellectual or social functions with onset 
during the developmental period (i.e. prior to the age of 18 years) that represent a decline from 
a previous level of functioning could be diagnosed as dementia if all diagnostic requirements 
for dementia are met and the impairments are known to be caused by an etiology that is 
specifically associated with dementia. Otherwise, if the impairments are known to be due to a 
medical condition and diagnostic requirements for another neurodevelopmental disorder (e.g. 
a disorder of intellectual development) are not met, a diagnosis of other specified secondary 
neurodevelopmental disorder should be considered.
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Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere

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Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere
Boundary with disorders of intellectual development or autism spectrum disorder
If the symptoms meet the diagnostic requirements of disorders of intellectual development 
or autism spectrum disorder and are judged to be the direct pathophysiological consequence 
of a medical condition with onset during the prenatal or developmental period (e.g. fragile X 
syndrome), both disorder of intellectual development or autism spectrum disorder and the 
underlying medical condition should be diagnosed, and a diagnosis of other specified secondary 
neurodevelopmental syndrome should not be assigned. However, if the diagnostic requirements 
of a disorder of intellectual development or autism spectrum disorder are not fully met (e.g. 
limitations in intellectual functioning are present without limitations in adaptive functioning), 
and the symptoms are attributed to a medical condition with onset during the prenatal or 
developmental period, a diagnosis of other specified secondary neurodevelopmental syndrome 
may be assigned.
Boundary with developmental motor coordination disorder
In developmental motor coordination disorder, individuals exhibit significant delays in the 
acquisition of gross and fine motor skills during the developmental period, and impairment in 
the execution of coordinated motor skills that manifest in clumsiness, slowness or inaccuracy of 
motor performance. If the difficulties with motor coordination are solely attributable to a disease 
of nervous system (e.g. cerebral palsy, muscular dystrophy), a disease of the musculoskeletal 
system or connective tissue, a sensory impairment (especially severe visual impairment) or joint 
hypermobility, a diagnosis of other specified secondary neurodevelopmental syndrome should be 
assigned rather than developmental motor coordination disorder.
Boundary with stereotyped movement disorder
Stereotyped movement disorder is a neurodevelopmental disorder that is characterized bythe 
presence of persistent voluntary, repetitive, stereotyped movements (e.g. body rocking, head 
banging) that result in significant interference with the ability to engage in normal daily activities 
or result in severe bodily injury. Stereotyped movement disorder is diagnosed even if it is judged 
to be caused by a medical condition classified elsewhere, and a diagnosis of other specified 
secondary neurodevelopmental syndrome is not assigned.
Boundary with other neurodevelopmental disorders
The diagnosis of secondary neurodevelopmental disorder should be assigned instead of other 
neurodevelopmental disorders when the symptoms are judged to be due to an underlying medical 
condition. (This does not apply to disorders of intellectual development, autism spectrum disorder 
or stereotyped movement disorder.)
Boundary with developmental difficulties caused by substances or medications, 
including withdrawal effects
When establishing a diagnosis of other specified secondary neurodevelopmental syndrome, it 
is important to rule out the possibility that a medication or substance is causing difficulties in 
the acquisition or execution of specific intellectual, motor or social functions instead of – or in 
addition to – an underlying medical condition. This involves first considering whether any of 
the medications being used to treat the medical condition are known to cause developmental 
difficulties at the dose and duration at which it has been administered. Second, a temporal 
relationship between the medication use and the onset of the developmental difficulties should 
be established (i.e. the developmental difficulties began after administration of the medication).
Secondary mental or behavioural syndromes associated with disorders and diseases classified elsewhere