Lecture 11 Flashcards
(10 cards)
Spina Bifida
Neurodevelopmental disorder and most common neural tube defects. Errors in development of caudal spinal cord. If it doesnt close at top, anencephaly occurs (no brain), but if bottom doesn’t fuse properly, spina bifida occurs (split spine). Vertebral arches fail to develop leading to maldevelopment of vertebral column, spinal cord, nerves and associated muscles. Sac-lic cyst may protrude from spine and may have nervous tissue. Cyst can be open/closed (covered by skin). 214000-322000 affected pregos
spina bifida occulta
most mild form. Affects lower back (L5-S1) where vertebrae fail to form, but, no protrusion of SC. Cutaneous stigmata at lesion level which may be associated with cyst in SC or tethered SC. Associated with anorectal/urogenital malformations, bowel, bladder and sexual disfunction. Also cognitive impact.
Meningocele
Sac of CSF filled cyst at level where fusing doesn’t occur. SC doesn’t fill sac, but issue still arise
Myelomeningocele
Cyst where spinal nerves/cord protrudes into cyst with meninges, lumbar and sacral region. Results in limb and muscular paralysis, decrease sensation and incontinence. Most severe but most common (~90% cases). Surgery prior or soon after birth.
symptoms
- cerebral ventricle and abnormality
- fluid cyst in spinal cord
- hydrocephalus
- chiari II malformation
Hydrocephalus
‘water head’. Build-up of CSF in ventricles. It exerts pressure on cerebral hemisphere causing damage and causes the skull to swell. Poor neurological outcomes = increase pressure. Shunts can drain fluid. can be placed prenatally.
chiari II malformation
Cerebellum and brainstem protrude through foramen magnum into vertebral column, compressing it. Sensory and motor symptoms arise. May require prenatal brain decompression surgery.
treatment and management
In utero diagnosis (ultrasound) in 1st trimester or maternal levels of alpha-fetoprotein. Lesion location determines finctional effects, but, generally paralysis, numbness, bladder/bowel and sexual disfunction. cognitive dysfunction common. No cure, just symptom managemet to maintain quality of life. This can be assisted by early diagnosis and specialist care. Mean survival 50 yrs with deaths from CNS dysfunction, death, urological disease, sepsis.
Causes
multifactorial. Mostly sporadic, but could be genetic vulnerability. Females more likely to get it, prevalence is lower in some European countries but more prevalent in China. Maternal health (diabetes, obesity, hypothemia, substance abuse, drug exposure, air pollution, lack of vitamins including B12 and folate. Folate is critical in neural tube closure. Recommendation to take 400-800ug daily. 58 countries supplement grain products with folic acid. Prevents 200000 cases yearly
decreasing risk in Australia
Folic acid fortification in grain products (2-3mg folic acid/kg flour). Lost cost saving $1.5 million in healthcare, increase productivity and increases equity in high-risk populations. Net benefit for society.
