Spina bifida is congenital disorder. It is classified as a neural tube defect (a disorder involving incomplete development of the brain, spinal cord, and/or their protective coverings), caused by the failure of the fetal spinal column to close completely during the first month of pregnancy. Infants born with Spina Bifida sometimes have an open lesion on their spine where significant damage to the nerves and spinal cord has occurred. Although the spinal opening can be surgically repaired shortly after birth, the nerve damage is permanent, resulting in varying degrees of paralysis of the lower limbs. Even when there is no lesion present there may be improperly formed or missing vertebrae and accompanying nerve damage.
Spina Bifida can be classified as one of three subtypes:
1) Myelomeningocele is the most severe form, in which the spinal cord and its protective covering (the meninges) protrude from an opening in the spine. The protruded portion of the spinal cord and the nerves that originate at that level of the cord are damaged or not properly developed. As a result, there is usually some degree of paralysis and loss of sensation below the level of the spinal cord defect. Thus, the higher the level of the defect the more severe the associated nerve dysfunction and resultant paralysis may be. This may lead to difficulty ambulating, musculoskeletal deformities of the hips, knees or feet, and decreased muscle tone.
myelomeningocele at lumbar area
2) Meningocele in which the spinal cord develops typically but the meninges and spinal fluid protrude from an opening. The nervous system usually remains intact.
unfused arch at C1
3) Spina Bifida Occulta is the mildest form, in which one or more vertebrae are malformed and covered by a layer of skin. This condition is asymptomatic in most cases. The incidence of spina bifida occulta is approximately 10% of the population, and most people are diagnosed incidentally from spinal X-rays.
at S1 juncture
Children with Spina Bifida present with a wide spectrum of motor and sensory impairments. The extent of the impairment is directly related to the level of the cyst and the level of the spinal cord defect. If the nerve roots are damaged or spinal cord is dysplastic, the child will have a flaccid type of motor paralysis with lack of sensation, the classic lower motor neuron presentation. If part of the spinal cord below the myelomeningocele is intact and has innervation, the result is a spastic type of motor paralysis.
The higher the level of the lesion, the greater the degree of muscular impairment and the less likely the child with be able to ambulate independently(without use of orthoses or assisted device).
Function Related to Level of Lesion
- Trunk Weakness
- May lead to: positional deformities of hips, knees and ankles
2) High Lumbar(L1-L2)
- Unopposed hip flexors and some adductors
- May lead to: hip dislocation, lumbar lordosis, knee flexion and plantar flexion
3) Midlumbar (L3)
- Strong hip flexors, weak hip rotators, antigravity knee extension
- May lead to: hip dislocation, subluxation, genu recurvatum
4) Lower Lumbar (L4/L5)
- (L4)Strong quadriceps, medial knee flexors against gravity, ankle dorsiflexion and inversion
- (L5)Weak hip extension, aduction, good knee flexion against gravity, weak plantar flexion with eversion
- May lead to: equniovaus, calcaneovarus or calcaneocavus foot
5) Sacral (S1)
- Hip abductors intact, weak plantar flexors
- May lead to: poor pushoff
6) Sacral (S2-S3)
- Hip extensors and ankle plantar flexors intact
- Major concern: genitourinary complications
Children with Spina Bifida are at risk of developing:
1) Osteoporosis: Therefore at a greater risk of developing fractures. With therapeutic focus on weight bearing and alignment Physical Therapy can address deformities and limitations caused.
2) Scoliosis: Can be either congenital or acquired due to muscle imbalances in the trunk. As a clinician be mindful of rapid onset of scoliosis, as this can be a sign of tethered cord or hydromelia.
3) Kyphosis/Lordosis: Spinal deformities more likely in higher level lesion. Be mindful of alignment in all developmental positions, consider effect of gravity on malleable spine.
4) Arnold-Chiari Malformation: Involves cerebellum, medulla, and cervical spine. Becuase cerebellum is not fully developed, hindbrain is displaced downward through foramen magnum. CSF flow is obstructed causing fluid build up within ventricles of brain. This can result in hydrocephalus. May also affect cranial nerve and brain stem function. Be mindful of swallowing difficulties.
5) Hydrocephalus: Can be treated surgically with placement of a ventriculoperitoneal shunt, which drains excess CSF into peritoneal cavity. Be mindful of prolonged time spent in head down position, because this may disrupt flow of fluid. Also be aware of signs and symptoms of shunt malfunction(i.e. irritability, seizures, vomiting, and/or lethargy)
6) Hydromelia: Characterized by accumulation of CSF in central canal of spinal cord. Can cause rapidly progressing scoliosis, upper extremity weakness and increased tone. Be mindful of these signs and alert attending physician immediately.
7) Tethered Cord: Because of scarring from surgical repair of the myelomeningocele, adhesions can form and can anchor spinal cord at lesion site. Spinal cord is then “tethered” and unable to freely move upward within vertebral canal as child grows. Be mindful of progressive neurological dysfunction, such as a decline in motor and sensory function, pain or loss of previous bowel and bladder control. Prompt surgical correction can usually prevent permanent neurologic damage.
8) Sensory Impairment: Sensory loss does not necessarily correlate with motor level of paralysis. It is important to test the entire dermatome. Can lead to skin and tissue breakdown, due to pressure and temperature as child is unable to “feel” pain. Be mindful of pressure relief techniques, skin inspection and wearing schedule for any orthotic devices to prevent pressure ulcers.
9) Bowel and Bladder Dysfunction: Sacral levels S2-S4 innervate the bladder and are responsible for voiding and defecation reflexes. With motor and sensory loss, the child has no sensation of bladder fullness or of wetness. If tone in bladder wall is increased, the bladder cannot store typical amount of urine and empties reflexively. Be mindful as urinary dysfunction may cause kidney damage. Children can learn self-catheterization to gain continence. As PT we can help teach functional activities and strategies to help achieve this task.
10) Latex Allergy: If exposed to latex many children with Spina Bifida are prone anaphylactic reaction that can be life threatening. Avoid contact with latex products, including surgical gloves, elastic bands, rubber balls and balloons.
Goals of Treatment
As Pediatric Physical Therapists, our goals encompass on the individual needs of each child. As part of a multi-disciplinary team we focus on enhancing quality of life and maximizing a child’s functional independence. We work closely with families to enhance activities of daily living in the home, school and community. We also address a child’s social and emotional issues that result from the diagnosis and related impairments.