Spina Bifida

Question 1

What is meant by spina bifida occulta?

Answer 1

Congenital abnormality
Improper vertbral arch fusion
The meninges, spinal cord do not protrude from the spinal canal

Question 2

What are the symptoms of spina bifida occulta?

Answer 2

Improper vertbrae formation - may show as birth mark typically with tufts of hair, or discolouration or dimpling
Mildest form - usually asymptomatic in the newborn

Question 3

What are the different types of spina bifida cystica?

Answer 3

Meningocele - meningeal sac protrudes, covered by skin
Myelomeningocele - meninges and spinal cord protrude through
Myelocele (aka open) - spinal cord exposed without meningeal covering

Question 4

Define spina bifida

Answer 4

A generalised term for the congenital abnormality neurological condition resulting from failure of the neural tube closure to varying degrees.
Results in herniation of vertebral column content

Question 5

Describe the process of neuralation relevant to spina bifida

Answer 5

Nonfusion of the caudal portions of the neural tube and local failure of vertebral arch development
Allows for protrusion/dimpling at the level of the defect
Defect can occur at any level but most commonly the lumbar/sacral level.

Question 6

What other congenital defects commonly accompany myelomeningocele?

Answer 6

Hydrocephaly
Chiari malformation
Significant neurological impairements

Question 7

What is a major preventable risk for spina bifida?

Answer 7

Folic acid deficiency

Question 8

What are the risk factors for spina bifida?

Answer 8

Nutritional - inadequate folic acid before and in early pregnancy
Maternal diabetes mellitus, obesity or teratogenic drugs (carbamazepine, valproate)
FH

Question 9

What are the signs and symptoms of a myelomeningocele?

Answer 9

Motor and sensory impairements - paralysis, weakness, loss of sensation - depends on level of the defect
Neurogenic bladder and bowel dysfunction - recurrent UTI, renal impairment etc
Orthopaedic abnormalities - clubfoot or scoliosis or hip subluxation

Question 10

What pre-natal scans can be done to identify spina bifida?

Answer 10

Bloods - maternal serum alpha-fetoprotein elevated if open
Imaging - US for spine and brain
Invasive - amniocentesis - elevated acetylcholinesterase confirms open

Question 11

What post natal investigations can be done for spinal bifida?

Answer 11

Bedside - neurlogical exam (motor and sensory deficits)
Imaging - MRI/CT for extend of damage and associated anomalies, urodynamic studies - to assess bladder function

Question 12

What is the method of prevention for spinal bifida?

Answer 12

Folic acid supplementation
400micrograms/day from 3months prior to conception until 12 months gestation
Higher risk 5mg/day

Question 13

What are the treatments for spina bifida?

Answer 13

Prenatal - foetal surgery - in utero repair or myelomeningocele
Post natal - closure of spinal defect within 24-4hrs to reduce infection/damage
Long term - MDT, physio, bladder and bowel management (catheter, meds), orthopaedic interventions