INCOMPLETE DEVELOPMENT OF BRAIN,SPINAL CORD &MENINGES

1. SPINA BIFIDA
DR.SUNIL KAMBLE
ASSISTANT PROFESSOR
DEPT.OF GEN.SURGERY
MNR MEDICAL COLLEGE,SANGAREDDY

2. • Definition
• Incidence and prevalence
• Causes
• Risk factors
• Embryology
• Classification
• Screening and diagnosis
• Treatment
• Physical therapy
• Prevention
• Prognosis
• Take home message

3. • Spina bifida is a developmental abnormality
caused by a failure of fusion of the vertebral
arches and possibly the underlying neural
tube,characterised by the incomplete
development of the brain,spinal
cord,meninges.(2,7)
• Spina bifida is a primary neurological
disorder.(7)

4. Incidence and Prevalence
• Spina bifida cystica-1:300 live births.(7)
• Associated with hydrocephalus.
• More common in hispanics and caucasians.
• Worldwide incidence 400,000 per annum.
• Folic acid use has reduced incidence by 70% in
the past 20 yrs.
• Ireland
• 1979-32 per 10,000
• 1982-22 per 10,000(2)

5. Causes
• Not known.
• Genetic , nutritional,
and environmental
factors play a role.
• Deficiency of folic acid.

6. Risk factors
A. Couples who already had an affected baby
B. Obese women
C. Diabetes
D. Anti-seizure medicines
E. Folic acid deficiency
F. Mutation in methylenetetrahydrofolate
reductase gene

7. Embryology
• Formation of notochord
• Origin : primitive node/pit
• Like the primitive streak , the primitive pit
cells proliferate and then migrate cranially in
the midline , towards the buccopharyngeal
membrane , and form a rod like notochordal
process.(3)

8. Neurulation
• It is the process by which the neural tube is
formed.
• The stages of neurulation include the formation
of:
• Neural plate
• Neural groove
• Neural folds and their fusion
• Neural crest cells
• Neural tube

9. • Begins during early part of the 4th week(22-23
days).
• Ends by the end of 4th week(27 days).
• Is induced by the notochord.

10. • Under the inducing
effect of the developing
notochord, the
overlying ectodermal
cells thickens to form
the neural plate.

11. • The neural tube
broadens and extends
cranially as far as the
buccopharyngeal
membrane , and later
on grows beyond it.

12. • On 18th day : the neural
plate invaginates to
form neural groove and
neural folds.

13. • By the end of 3rd week ,
the neural folds move
to the midline and fuse
to form the neural tube.
• The fusion begins in
cervical region and then
extends both in cranial
and caudal direction.

14. • The neural tube
separates from the
surface ectoderm , lies
in the midline ,dorsal to
the notochord.

15. • Neural tube is open at
both ends
communicating freely
with the amniotic
cavity.
• The cranial opening ,
the rostral neuropore
closes at about 25th day
and the caudal
neuropore closes at
about the 27th day.

16. • The cranial 1/3 of the
neural tube represent
the future brain.
• The caudal 2/3
represents the future
spinal cord.(6)

18. Neural Tube Development
• Neural plate
development-18th day
• Cranial closure-24th
day(upper spine)
• Caudal closure-26th
day(lower spine)

19. Types of Neural Tube Defects
ANENCEPHALY Brain and skull poorly
developed
Death inevitable
Failure of skin and muscle
formation
Variable outcome
Urgent closure
Exposed neural tissue 90% need VP shunt
Distal limb innervation
affected
Neuropathic bladder
MENINGOCELE Failure of spinal fusion
Dural sac protrudes
Usually no neural
consequences
Rarely bladder function
affected
Skin covered defect

20. ENCEPHALOCELE Usually occipital
Defect in cranial bone
Herniation of meninges
and brain to varying
degree
Variable outcome
Sometimes shunt needed
SPINA BIFIDA Occulta Hamartoma at site
Sinus occasionally
Skin intact
Bony vertebral arch
deficient
Excellent outcome

21. Types Of Neural Tube Defects

22. Spinal Rachischisis
• Developmental birth defect involving the neural
tube.
• In utero, the neural tube fails to close completely.
• This anomaly originates when the posterior
neuropore fails to close by the 27th intrauterine
day.
• As a consequence the verterbrae overlying the
open portion of the spinal cord do not fully form
and remain unfused and open , leaving the spinal
cord exposed .

23. • Patients with rachischisis have motor and
sensory deficits, chronic infections, and
disturbances in bladder function.
• This defect often occurs with anencephaly.

24. Encephalocele
• Midline defect in the
bones of the skull, which
allows protrusion of
meninges only or gross
herniation of brain tissue.
• 10% of neural tube
defect.
• Common in female.
• The usual bony site is the
occipit but frontal
encephaloceles are more
common and only seen in
Asia.

25. Associated
• Microcephaly
• Cerebral anomalies
• Dandy-Walker Cyst formation
• Hydrocephalus
• Dysplasia of cerebellum and optic pathway
• Congenital lesions such as cleft palate ,cardiac
,lung and renal anomalies.

26. Classification
• Spina bifida occulta
• Spina bifida cystica:
Meningocele
Myelomeningocele
Encephalocele

27. Meningocele
• Cele-sac(Latin word)
• Fluid filled sac with
meninges involved but
neural tissue
unaffected.

28. • Uncommon
• Presents as swelling
along the spinal cord.
• Site;lumbar region
• No neurological defect.
• Spinal cord is normal.
• Lower limbs are normal.

29. Myelomeningocele
• The unfused portion of
the spinal column allows
the spinal cord to
protrude through an
opening.
• The meningeal
membranes that cover
the spinal cord form a sac
enclosing the spinal
elements.
• Commonest form.
• Most severe.

30. • Most common site-
lumbar and sacral
areas.
• Presents as swelling
along the spinal
columns.

32. Associations
• Hamartomatous lesions : Hemangioma ,lipoma or
a naevus
• Deformities of the lower limbs
Hip dislocation or subluxation
Hypoplastic lower limbs
Genu recurvatum
Talipes deformities of feet
Hydrocephalus
Severe kyphosis

33. • Neurological deficits:
Motor and sensory loss to the lower limbs
Paralysis of lower limb muscle
• Rectal prolapse
• At least 90% of patients have a neuropathic
bladder with disturbances of detrusor and
sphincter muscle activity.

34. Spina Bifida Occulta
• Occulta in Latin means “Hidden”
• Mildest form of spina bifida.
• Incidence-10%
• There is a small defect or gap in one or more
vertebrae of the spine.
• Spinal cord does not protrude.
• Spinal cord and nerves are normal.

35. • Skin at the site of the
lesion may be normal or
it may have some hair
growing from it,there
may be a dimple in the
skin, or a birth mark.
• Asymptomatic.

36. Spina bifida occulta
• Diastematotomyelia
• Lipomyelomeningocele
• Tethered filum terminale
• Anterior sacral meningocele
• Myelocystocele
• Caudal regression syndrome

37. Diastematomyelia
• Split cord malformation(SCM).
• Presents as tethered cord syndrome.
• Common-lower thoracic or upper lumbar spine.
• Most patients have midline cutaneous
abnormality , but it does not necessarily
correspond to the level of cleft.
• Kyphoscoliosis eventually develops.
• Symptoms-Back pain, gait disturbance , muscular
atrophy , urologic complaints.

38. Type I SCM(Split cord malformation)
• Consists of two hemicords seperated by a bony or
cartilagenous median septum,with each housed
in its own dural sheath.
Type II SCM
• Consists of two hemicords enveloped in the same
dural sheath , and seperated by a fibrous septum.
• Both are associated with tethering.
• Surgery indicated for progressive neurological
deficit and scoliosis.

39. Lipomyelomeningocele
• Here lipomatous tissue
inserts into the conus ,
and herniates through the
bony defect dorsally to
attach to a subcutaneous
mass.
Two varieties
• One that inserts caudally
into the conus,and
• One those attach to
dorsal surface of spinal
cord.

43. Tethered Filum Terminale
• Filum terminale gets
thickened and adhered to
the spinal canal.
• Failure of ascent of spinal
cord during growth.
• Leads to Arnold Chiari
malformation(type
I),syringomyelia,
scoliosis,incontinence.
• Diagnosis-MRI
• Treatment-Division of filum
terminale to release the
tension in spinal cord.

44. Caudal regression syndrome
• Heterogenous costellation of
congenital caudal anomalies
affecting the caudal spine and
spinal cord, the hindgut ,the
urogenital system, and the lower
limbs.
• Partial agenesis of the
thoracolumbosacral spine,
• Imperforate anus,
• Malformed genitalia,
• Bilateral renal dysplasia or
aplasia,
• Pulmonary hypoplasia , and
• Extreme external rotation and
fusion of the lower
extremities(syringomyelia).

45. Caudal Regression Syndrome
• Welch and Aterman classified congenital sacral
anomalies into 4 distinct clinical types.
1. A non-familial type associated with maternal diabetes
mellitus showing complete absence of the sacrum and
lower vertebrae with multiple congenital anomalies.
2. Agenesis of the distal sacral or coccygeal segments.
3. Hemisacral dysgenesis with presacral teratoma and
4. Hemisacral dysgenesis with anterior meningocele.
• Autosomal dominant inheritance was suggested for the
last three types.

46. Caudal regression syndrome

47. Complications
Factors that affect severity of complications include:
• The size and location of the neural tube defect.
• Whether skin covers the affected area.
• Whether spinal nerves come out of the affected
area of the spinal cord.
• Children with myelomeningocele may experience
physical and neurological problems,including lack
of normal bowel and bladder control, and or
partial or complete paralysis of their legs.

48. Physiological changes below the lesion
Abnormal nerve conduction resulting in
• Somatosensory losses
• Motor paralysis, including loss of bowel and bladder
control
Abnormal nerve conduction resulting in
• Changes in muscle tone
• Note- Muscle tone can range from flaccid to normal to
spastic ; may have UMN signs with/without true spastic
paraperesis.
• Progression of neurologic dysfunction or change in
neurologic status more concerning.

49. Anatomical changes below the lesion
• Musculoskeletal deformities(scoliosis)
• Joint and extremity deformities(joint
contractures ,club foot, hip subluxations,
diminished growth of non-weight bearing
limbs)
• Osteoporosis
• Abnormal or damaged nerve tissue.

50. Other medical problems that occur
• Hydrocephalus(70-90%)
• Chiari II malformation(change the brain’s
position)
• Tethered spinal cord(held in place by
connective tissue)
• Urinary tract disorders
• Latex allergy(73%)
• Learning disabilities(20%)

51. Prsenting Symptoms and Signs of
Occult Spinal Dysraphism
Symptoms/signs incidence
Foot deformity 39%
Scoliosis 14%
Gait abnormality 16%
Leg weakness 48%
Sensory abnormality 32%
Urinary incontinence 36%
Recurrent urinary tract infections 20%
Fecal incontinence 32%
Cutaneous abnormality 48%

52. Screening and Diagnosis
(1) Blood tests
• Second trimester maternal serum alpha
fetoprotein(MSAFP)
• Alpha-feto protein(AFP) is made naturally by the
fetus and placenta.
• But if abnormally high levels of this protein
appear in the mother’s bloodstream it may
indicate that the fetus has a neural tube defect.
• The MSAFP test, however, is not specific for spina
bifida(positive predictive value 2-4%).

53. (2) Ultrasound
• An advanced ultrasound can also detect signs of spina
bifida(sensitivity 96%,specificity 100%)
(3) Amniocentesis
• An analysis indicates the level of AFP present in the
amniotic fluid.
• A small amount of AFP is normally found in amniotic fluid.
• When an open neural tube defect is present , the amniotic
fluid contains an elevated amount of AFP because the skin
surrounding the baby’s spine is gone and AFP leaks into the
amniotic sac.
(4)MRI

54. • MRI showing occipital
encephalocele

56. • MRI showing
lipomeningomyelocele

57. Treatment
• There is no cure for spina bifida.
• The nerve tissue that is damaged or lost
cannot be repaired or replaced.
• Treatment depends on the type and severity
of the disorder.
• Children with the mild form need no
treatment.
• Moderate to severe cases, surgical closure of
back lesion within 6 months.

58. • There is no known cure for nerve damage
caused by spina bifida.
• To prevent further damage of the nervous
tissue and to prevent infection , surgeon
operate to close the opening on the back.
• The spinal cord and its nerve roots are placed
back into the spinal canal and covered with
meninges.

59. • In addition , a shunt may be surgically installed
to provide a continuous drain for the excess
CSF produced in the brain , as happens with
hydrocephalus.

60. Surgery for meningomyelocele
• A.Position of the
patient on the
operating table ad an
elliptical incision at the
junction of the
membrane and the
skin.

61. • B.Membrane being
eplised to free the
neural plaque.

62. • C.Plaque lying in the
dural layer

63. • D.Dura is closed with a
continuous suture

64. • E.Skin is closed with
interrupted sutures.

65. Surgery for Lipomeningocele

67. Surgery for Diastematomyelia

68. Surgery for Anterior Sacral
Meningocele

69. Physical Therapy Management
Pre-closure
• ROM assessment,therapeutic positioning for
sleeping.
Post-closure
• Sensory assessment , home programme
instruction(ROM exercises, handling and
carrying positions, and therapeutic positioning
for sleeping).

70. Newborn
• Therapeutic positioning
pre- and post-surgery
for repair of
myelomeningocle.
• Keep an eye out for
shunt malfunction.

71. The Young Toddler
• Typically seen in a transdisciplinary management
of multiple and varied medical, surgical
needs,and therapeutic needs.
• Transdisciplinary teamwork enhances
communication ,prevents delays in care,
coordinates management.
• Transdisciplinary team consists of
;Neurosurgeon,Orthopedician,Urologist,Physioth
erapist,Nurse,Social worker, and may include
others.

72. Concerns for the Young Toddler
Developmental delay
• Delayed and abnormal head and trunk
control, righting,and equillibrium responses.
Handling/Positioning
• The child needs to develop upright head
control in many positions.

73. Structural Problems:Club Foot
• Congenital deformity
with the following
components;
• Adductus
• Equinus
• Varus,and
• Medial rotation

74. • Bilateral talipus
deformities of feet

75. Structural Problems:Sloppy Knees
• Low lumbar paralysis;
• “sloppy knees”from
absent lateral
hamstrings(and active
medial hamstrings and
quadriceps).

76. Orthoses and Equipment Typical for
Children with Spina Bifida
Total contact arthrosis HKAFO(hip-knee-ankle-foot-orthosis
A-frame (Toronto standing frame) Roliator walker
Parapodium(orlau swivel walker) Floor reaction AFO(A.K.A.anti-crouch
arthrosis)
Start cart Articulating ankle joints in S1-level lesions
Reciprocating gait orthosis ( new
isocentric RGO)
Twister cables

77. Example of Parapodium
• Commonly used for
children with high
lesions(T12-L3)
• Offers support to the
hips, knees,and ankles.

78. The Activities for the Young Toddler
• Stimulate automatic balance responses against
gravity in all positions to activate responses in the
lower extremities.
• Encourage brief periods of well-aligned weight-
bearing throughout the day to stimulate
acetabular development(reducing likelihood for
hip dysplasia) and prevent osteoporosis.
• Avoid infant walkers,jumper seats, swings,
bouncer chairs, excessive use of infant car seats.

79. The Adolescent
Psychosocial issues
• Dependency on parents or caretakers
• Poor hygiene form lack of independence and
motivation
• Need for vocational training
• Loss of “cure fantasy”during adolescence

80. Wheelchair Issues
• Many disagree with the statement that the family
should wait until the child age of 5 or 6 yrs to
obtain the first wheelchair.
• Consider the child’s health and quality of life with
and without wheelchair.
• Consult with the family and interdisciplinary team
experts(physicians, seating clinical staff,
physiotherapist with seating experience,vendors)
before making wheelchair decisions.
• Errors are costly.

81. The Adult
• Need to focus on health promotion and
fitness.
• Watch for overuse syndrome, especially in
upper extremities and also, low back pain.
• Monitor for safe and properly fitting
equipment (wheelchair, bathroom devices,
supportive and protective shoes).
• Model advocacy to improve access to
community based resources.

82. The Adult
Need to change the status quo
• Despite 21st century medicine and treatment
advances, many children with spina bifida
never achieve independence - Many never
marry , never live away from parents.
• There is not necessarily correaltion between
the level of independence and level of lesion.

83. Prevention
• Folic acid reduces the
risk of having a child
with a neural tube
defect,such as spina
bifida.
• Dose-400micrograms
daily.
• Source-dark green
vegetables,egg
yolks,fruits like orange.

84. Prognosis
Spina bifida is a:
• Static
• Nonprogressive defect.
• With worsening from secondary problems.
• The prognosis for a normal life span is
generally good for a child with good habits
and a supportive family caregiver.

85. Take Home Message
• Due to folic acid intake 70% of cases are not
seen now-a days.
• There is no known cure for nerve damage
caused by spina bifida.
• Role of physiotherapy is important in spina
bifida patients.

86. References
1.Principles of Neurosurgery by Setti S.Rangachari
2.Pediatric Surgery by Prem Puri and Michael
Hollwarth
3.Human Embryology by Inderbir singh-7th edition
4.Rob and Smith’s pediatric surgery
5.Avery’s Diseases of the newborn-9th edition
6.Langman’s Embryology-12th edition
7.Bailey and Love Short Practice of Surgery -26th
edition