Neural Tube Defects - background
a. Folate supplementation reduces recurrence by 72%
Neural Tube Defects - classification
a. Open spinal dysraphism
i. Characterised by cleft in the vertebral column with corresponding defect in the skin
ii. Exposed meninges and spinal cord
iii. Comprise 80% of all NTDs
iv. Associated with Chiari malformations and ventriculomegaly
v. Includes
1. Spinal
a. Myelomeningocele (contains neural tissue)
b. Meningocele (no neural tissue)
2. Cranial
a. Encephalocele (brain and meninges)
b. Anencephaly (absence of a major portion of the brain, skull, and scalp)
b. Closed spinal dysraphism = spina bifida occulta
i. Characterised by cleft in vertebral column
ii. No epithelial defect – may have tuft of hair, dimple, birthmark
iii. Not usually associated with cranial malformations
iv. Includes
1. Lipomyelomeningocele (an abnormal growth of fat attaches to the spinal cord and its membranes)
2. Lipomeningocele
92% occur at/below L3
Neural Tube Defects - investigation
Closed Spinal Dysraphism - general
a. Cutaneous
i. Patch of hyperkeratosis
ii. Patch of hypertrichosis
iii. Patch of hyperpigmentation
iv. Patch of epidermal atrophy
v. Subcutaneous mass (lipoma or neurofibroma)
vi. Capillary haemangioma or cutaneous angioma
vii. Dorsal dermal sinus
viii. Sacrococcygeal pit
ix. Sacrococcygeal dimple
x. Caudal cutaneous appendage
xi. Isolated deviation of the intergluteal fold
b. Neurological
i. Neurological abnormalities in legs
1. Motor weakness
2. Sensory loss
3. Reflex changes
4. Abnormal plantar response
ii. Tethered cord syndrome
1. Stretch-induced dysfunction of the caudal spinal cord and conus
2. Presentation of several forms of closed spinal dysraphism
3. Results in back pain, bladder dysfunction, leg weakness, calf muscle atrophy, reduced tendon reflexes, loss of sensation, scoliosis + foot deformities
c. Urological
i. Neurogenic bladder dysfunction
ii. Urological abnormalities
d. Musculoskeletal
i. Scoliosis
ii. Kyphosis
iii. Lordosis
iv. Leg length discrepancy
v. Foot deformities
Complications Spina Bifida - neuro (hydrocephalus, tethered cord syndrome)
a. Hydrocephalus
i. 3/4 develop significant hydrocephalus requiring treatment
ii. By 1 month of age 80% develop hydrocephalus
iii. Levels 2 and 3 (thoracic + upper lumber) more likely to get hydrocephalus
iv. Usually present by 1 month of age
1. Shunts are usually inserted in first 2/12 of life
2. Rarely develops after 6 months
Intellectual function/disability highly correlates with hydrocephalus
b. Tethered cord
i. Traction, damage to neural tissue
ii. Common at birth
iii. Highest recurrence at peak longitudinal growth (puberty) but can occur at any time
iv. Monitor = serial MRI
v. Symptoms and signs- changes in:
1. Bladder/bowel function
2. Foot position
3. Back or lower limb pain
Complications Spina Bifida - urological (neuropathic bladder)
Neuropathic bladder
a. Key points
i. Urinary tract innervated by sacral segment
ii. All children expected to have neuropathic bladder – 25% continent, tend to be those with little or no sensory loss
iii. Renal failure was historically the major cause of death in those with Spina Bifida
iv. Intermediate bladder most common
b. Monitoring
i. Ultrasound – usually done every 6/12
ii. Other (urodynamics, MCS, creatinine)
c. Goals
i. Preserve renal function = ensure emptying + prevent infection
ii. Achieve continence
- Medical: intermittent catheterisation, anticholinergics, treat infections
- Surgical: botulinum toxin, sphincterotomy, vesicostomy, Mitrofanoff
NOTE 35% develop IgE mediated latex allergy
Spinda Bifida Complications - GIT (neuropathic bowel)
a. Key points
i. Usually in those with S2/S3 affected
ii. 25% of adults with spina bifida are bowel continent
iii. Most who are incontinent have poor sensation and either
1. Increased bowl outlet resistance constipation and overflow diarrhoea
2. Decreased bowel outlet resistance frequent stools throughout the day
b. Management
i. Diet, fluids – recommend low fibre diet to reduce volume of stool
ii. Regular sit, cough, push on toilet
iii. Laxatives – start laxatives very early (<2 years)
iv. Enemas, washouts
v. Anal plugs – previously used for swimming
vi. Biofeedback
vii. Malone procedure – antegrade washouts; usually appendix to skin
viii. Peristeen irrigation system – rectal catheter used to flush bowel
ix. (Exclude other causes of diarrhoea)
c. Continence nurses
i. Advise – management of bladder and bowels
ii. Training (CIC, washouts) – parents, carers, aides and patients
iii. Applications for funding
iv. Sourcing equipment (catheters, pads, nappies, specialised underwear)
v. Supplied by NDIS
Spina Bifida Complications - MSK
a. Based on age
i. Neonatal priorities
1. DDH
2. Clubfoot
ii. Childhood
1. Independence, mobility, positioning
4. AFO (ankle foot orthosis) most common aid
iii. Teenager
1. Monitor scoliosis
b. Mobility aids
i. The higher the lesion the less the chance of independent walking BUT the anatomical level does not always predict function accurately
c. Physiotherapy
1. If a sudden change may indicate tethering
d. Orthopaedic surgery
i. Common reason for admission
ii. Abnormal pressure on joints
iii. Scoliosis
e. Sensation
i. Sensory loss below level of lesion – patchy or dense
ii. High risk of pressure areas burns
1. Slow healing (poor blood supply)
2. Historically, common cause of death
3. Big cause of morbidity in adults
iii. Occupational therapists
Spina Bifida Complications - transition of care
a. Kidney, bladder and bowel most important long term
b. Less commonly have any further neurosurgical or orthopaedic interventions later in life
c. RCH/RMH transition program
d. Consider private insurance for urologist unless attends RMH
Lissencephaly - general
“Smooth brain”
Schizencephaly - general
Radiopedia: “generally speaking, schizencephaly is reserved for clefts lined by grey matter (polymicrogyria) thought to represent a true malformation, whereas porencephaly implies an encephaloclastic event (e.g. ischemia)”
Abnormal slits or clefts form in the cerebral hemispheres of the brain
Polymicrogyrias - general
Polymicrogyria is a condition characterized by abnormal development of the brain before birth. The surface of the brain normally has many ridges or folds, called gyri. In people with polymicrogyria, the brain develops too many folds, and the folds are unusually small.
Porencephaly - general
“Pore”
Radiopedia: “generally speaking, schizencephaly is reserved for clefts lined by grey matter (polymicrogyria) thought to represent a true malformation, whereas porencephaly implies an encephaloclastic event (e.g. ischemia)”
Corpus Callosum Agenesis - general
Holoprosencephaly - general
Mobius Syndrome
Duane Retraction Syndrome
Dandy-Walker Malformation
• Posterior fossa abnormalities including
o Cystic dilatation of the fourth ventricle
o Hypoplasia of the cerebellar vermis
o Hydrocephalus
o Enlarged posterior fossa
• Variable degrees of neurological impairment
• Unknown cause
Joubert Syndrome
• AR disorder – ciliopathy • Genetic heterogeneity • Associated with cerebellar vermis hypoplasia and pontomesencephalic molar tooth sign (depending on the interpeduncular fossa with thick and straight superior cerebellar peduncles) • Clinical manifestations o Hypotonia, ataxia (toddler) o Breathing abnormalities – episodic apnoea and hyperpnoea o Global developmental delay o Strabismus o Occulomotor ataxia • Associated features o Progressive retinal dysplasia – Leber congenital amaurosis o Coloboma o CHD o Microcystic kidney disease
Chiari Malformations - general
Types 1/2/3 - separate note
Chiari Malformations - types
a. Type I
i. Features
1. Cerebellar tonsils abnormally shaped
2. Displaced below level of foramen magnum
iii. Clinical manifestations
1. Insidious, present in adolescence (mean age 18yo)
2. Increased ICP
3. Cranial neuropathies
a. Hoarseness/VC paralysis
b. Tongue atrophy
c. Recurrent aspiration
d. Nystagmus (down beating)
4. Myelopathy
5. Cerebellar dysfunction = nystagmus, scanning speech, truncal ataxia
6. Pain (neck/occipital headache)
b. Type II = Arnold Chiari
i. Features
1. Downward displacement of vermis and tonsils
2. Brainstem malformation with beaked midbrain
3. Spinal myelomeningocoele (usually lumbosacral)
ii. Associations
1. Most have associated hydrocephalus (obstruction of CSF flow through posterior fossa)
2. Stenosis/atresia of cerebral aqueduct
3. Cerebellar dysplasia
iii. Clinical manifestations
1. Nearly always have myelomeningocoele usually detected at birth or antenatally
2. Dysphagia, stridor, aspiration, apnoeic spells, arm weakness
3. Progressive hydrocephalus common in late infancy
5. May have normal intelligence
c. Type III
i. Rare
1. High mortality in infancy – respiratory failure
2. If survive, usually severe neurological impairments
3. Intellectual disability
4. Epilepsy, hypotonia/spasticity
5. UMN and LMN signs
6. Cranial nerve palsies
Demyelinating conditions - list
ADEM and ATM (RCH) - background/sx/outcomes
ADEM and ATM (RCH) - ix/rx