Clinical features and diagnosis

Features can be classified as primary or secondary:

• Primary: inherent functional problems associated with the impact on the central nervous system of having been exposed to alcohol
• Secondary: social, emotional and vocational consequences that arise over time as a result of chronic poor fit between the person and their environment

Primary symptoms

1. Changes to facial features
2. Structural defects
3. Central nervous system involvement
4. Growth retardation

Secondary symptoms

Difficulties arising from a mismatch between the young persons’ skill set and their environment include:

• Disrupted schooling
• Trouble with law enforcement
• Legal confinement eg. Detention, jail, psychiatric care
• Inappropriate sexual behaviour
• Drug and alcohol abuse
• Comorbid mental health diagnoses

It was noted by Streissguth et al in 2004 that one of the strongest correlates of adverse outcomes was lack of early diagnosis; the longer the delay in receiving diagnosis, the greater the odds of adverse secondary outcomes.

Facial features

The characteristic facial features of FASD are:

1. Short palpebral fissures
2. Thin vermillion border
3. Smooth philtrum

Even when present at birth, these features become harder to detect as the child ages as well as being more difficult to recognize with cultural diversity.

Spectrum of children with FASD

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Other facial features that may be seen but are not included in the diagnostic criteria include:

• Midface hypoplasia
• Epicanthal folds
• Reduced interpupillary distance
• Flat nasal bridge
• Long philtrum
• Anteverted nares
• Reduced intercanthal distance
• Railroad track ears

Structural defects

Structural defects are seen in a variety of organ systems outside of the CNS. Defects include:

• Cardiac
  • ASD
  • VSD
  • Conotruncal defects eg. Tetralogy of Fallot
• Skeletal
  • Pectus – excavatum or carinatum
  • Hemivertebrae
  • Scoliosis
  • 5^th finger clinodactyly (40%!)
  • Camptodactyly
• Renal
  • Aplastic/dysplastic/hypoplastic kidney
  • Horseshoe kidney
  • Ureteral duplications
  • Hydronephrosis
• Ocular
  • Ptosis
  • Strabismus
  • Optic nerve hypoplasia
  • Refractive problems
• Auditory
  • Conductive or sensorineural hearing loss

Clinodactyly https://congenitalhand.wustl.edu/2012/07/clinodactly.html

Camptodactyly https://congenitalhand.wustl.edu/2012/03/camptodactyly.html

CNS involvement

Even if not meeting criteria for FAS, 70% of children with heavy prenatal alcohol exposure show neurobehavioural effects. There is variable expressivity of symptoms when comparing individuals, and even within the one child, symptoms may vary from day-to-day.

Defects may be structural or functional. Microcephaly (head circumference <3^rd centile) is present in 12% with FASD. Neuroimaging may reveal reduction in size or change in shape of the corpus callosum, cerebellum, or basal ganglia.

Abnormalities on neurological examination include:

• Abnormal tone
• Abnormal reflexes
• Cranial nerve deficits
• Poor coordination and balance
• Visual-motor difficulties
• Difficulty with motor sequence
• Right-left confusion

Functional abnormalities often occur in multiple domains including:

• Cognitive impairment (20% with FAS have an IQ <70)
• Difficulties with executive function eg. Poor organisation and planning
• Poor motor function eg. Messy handwriting
• Problems with hyperactivity, concentration and attention
• Difficulties with social skills and adaptive function eg. Poor understanding of social cues

Evaluation of FASD is ultimately done using a multidisciplinary team of specialists including paediatrician, speech pathologist, occupational therapist, psychologist, physiotherapist, social worker +/- neurologist +/- geneticist.

A diagnosis of FASD can be subdivided into 2 subcategories:

1. FASD with 3 sentinel facial features
2. FASD with less than 3 sentinel facial features

To assess an individual with prenatal alcohol exposure and/or suspected FASD, the following essential criteria must be considered:

1. Maternal alcohol use and other exposures
2. Neurodevelopmental impairment
3. Facial and other physical features

Australian guide to the diagnosis of fetal alcohol spectrum disorder (FASD)

1. Small palpebral fissures (reduced distance between the endocanthium and the exocanthium)

1. • Assess using palpebral fissure length charts
   • When measured in photographs, the length is often underestimated
   • Scandanavian (Stromland) charts if a child is under 6 years of age
   • Canadian (Clarren) charts if a child is over 6 years
   • Easy to use calculator which will determine your standard deviations –
2. Smooth philtrum (Rank 4 or 5 on the Washington Lip-Philtrum Guide)
   • Charts vary depending on ethnicity
3. Thin upper lip (Rank 4 or 5 on the Washington Lip-Philtrum Guide)
   • Charts vary depending on ethnicity

**t is important that the child DOES NOT smile during assessment of the philtrum/lip as this can alter lip thinness and philtrum thickness (see picture series B)**

Lip-philtrum assessment guide 

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