Positional plagiocephaly Flashcards
When is the peak prevalence of positional plagiocephaly?
4 months (~20 percent)
Why has there been an increase in positional plagiocephaly?
Back to Sleep campaign 1992 recommended avoidance of prone sleeping position due to SIDS
What is the treatment of positional plagiocephaly?
Repositioning, physical therapy, neck stretching in those with torticollis and cranial orthosis for refractory cases
How long do orthoses have to be worn?
23 hours a day for >3 months
Which factors are associated with developmental plagiocephaly?
This is plagiocephaly secondary to intrauterine forces. Factors include twins, breech delivery, first pregnancy, maternal age >35 years, prolonged labour, male, assisted delivery and cephalohaematoma.
What is the frequency of torticollis with positional plagiocephaly?
1 in 6 - due to haemorrhage and subsequent scarring into SCM resulting in shortening of the muscle. A band may be palpable.
What is the skull shape in positional plagiocephaly?
Classic parallelogram deformity: Unilateral occipital flattening with anterior displacement of the forehead and ear. Compensatory occpitial bossing and frontal recession on the contralateral side.
What is the standard examination for positional plagiocephaly?
Head circumference
Ant fontanelle / other feature of raised ICP
Suture palpation for ridging
Neurological examination
Visual assessment from the front, back, top and side
How can the extent of deformity be assessed in positional plagiocephaly?
Anthropometric assessment with calipers, photography or 3D scanning.
Measures include head length (from glabella to inion), head width (biparietal diameter) and transcranial diameter (diagonal measures from frontal - occipital).
**The difference between right and left transcranial diameters is the trans-diagonal difference and is used to diagnose positional plagiocephaly. The severity is expressed as the cranial vault asymmetry index = longer diagonal / shorter diagonal *100 **
The cranial index = (head width / head length) x 100 is used to determine the severity of bilateral positional plagiocephaly
How is the severity of positional plagiocephaly categorised?
A transcranial difference 3-10 mm = Mild (CVAI 3-6%), 10-12 mm = Moderate (CAI 6-9%) and >12 mm = Severe (9-11%).
What are the expected examination findings with positional plagiocephaly?
Ipsilateral occipital flattening and contralateral occipital bossing
Anterior displacement of the ipsilateral ear
Ipsilateral frontal bossing and contralateral flattening
Anterior displacement of the orbit / cheek if more severe
How do you differentiate positional plagiocephaly from uni-lambdoid synostosis
Positional plagiocephaly = PARALLELOGRAM
Lambdoid synostosis = TRAPEZIUM
How is the cranial base affected in unilateral synostosis?
The skull base is tilted with the high portion on the side of the lambdoid synostosis
What should be ruled out in patients with positional plagiocephaly?
Torticollis - due to sternocleidomastoid injury; Examine the passive range of neck movement and palpate for a SCM fibrous band.
When should imaging be performed for positional plagiocephaly?
Equivocal clinical examination where cannot be distinguished from uni-lambdoid synostosis
