Stanbridge - T6 - Neuro2 - W1 - Spinal Cord Injury and Myelomeningocele

• Neurologic Interventions II is a course which involves Spinal Cord Injury and Myelomeningocele
• The nervous system can be divided in central or peripheral
• The central nervous system is composed of the brain and spinal cord
• The peripheral nervous system is further divided into somatic and autonomic components
• The autonomic nervous system is divided into sympathetic and parasympathetic systems

Spinal Cord and Meninges

• Beneath the arachnoid layer lies the subarachnoid space, which contains CSF
• The spinal cord communicates sensory and motor information between the brain and peripheral nerves
• The spinal cord is continuous with the brain stem, and is housed in the vertebral column
• Located below the conus medullaris (at L1) is the cauda equina, which consists of nerve roots L2-S5
• Spinal cord composition includes white and gray matter
• Nerve fibers ascend and descend to and from the brain
• Dorsal/ posterior horn transmits sensory information
• Anterior/ ventral horn transmits motor information

Nerve Tracts

• Afferent nerve tracts carry information from the body to the brain
• An example of an afferent tract is the lateral spinothalamic tract
• Efferent tracts carry information from the brain to the body
• The corticospinal tract is an example of an efferent tract
• Nerves travel in fiber tracts
• Tracts are groups of nerve fibers that share a similar origin, destination, and function
• Tracts travel in white matter
• Afferent tracts are sensory, while efferent tracts are motor
• Sensory information about proprioception (position sense), vibration, two-point discrimination, deep touch, pain, temperature and pressure are carried in nerve tracts
• The dorsal columns carry information about proprioception (position sense), vibration, two-point discrimination, and deep touch
• The anterior/lateral spinothalamic tract carries information related to pain and temperature
• The corticospinal tract is the primary motor pathway
• The corticospinal tract controls skilled movements of the extremities
• It originates in the frontal lobe in the primary/premotor cortex
• It descends and then synapses on the anterior horn cell of the spinal cord
• The corticospinal tract crosses from one side to another in the brain stem
• The anterior horn cell is a large neuron located in the gray matter of the spinal cord
• Activation of an anterior horn cell stimulates a muscle contraction
• Alpha motor neurons innervate skeletal muscle
• Gamma motor neurons transmit impulses to the muscle spindle
• Muscle spindles are sensory organs found in skeletal muscle that respond to stretch
• Muscle spindles provide feedback to the CNS regarding muscle length
• A stretch reflex mechanism begins with a patellar tap; that information is then sent to the dorsal root
• A synapse occurs with an anterior horn cell
• Motor response is then initiated causing a reflex contraction of the quadriceps resulting in knee extension

Spinal Cord Injury (SCI)

• Spinal cord injury (SCI) is often a result of a traumatic injury such as, motor vehicle accidents, sports injuries, gunshot wounds, or falls

• Spinal cord is most often injured at C1-C2, C5-C7 and T12-L2 because movement (rotation) is greatest at these three segments leaving instability in these regions

• Traumatic SCI is often the result of direct or indirect forces

• Potential SCI injury types: cervical flexion/rotation, cervical hyperflexion, cervical hyperextension and compression

• Cervical flexion/rotation injuries are defined by posterior spinal ligament ruptures, upper vertebrae displaced over lower vertebrae, transection of the spinal cord, and rupture of intervertebral disc and anterior longitudinal ligament

• Cervical hyperflexion injuries are defined by anterior compression fracture, stretching of posterior longitudinal ligament, wedge fracture severs anterior spinal artery, and incomplete anterior cord syndrome

• Cervical hyperextension injuries are defined by a central type injury the compression of the spinal cord between ligamentum flavum and vertebral body

• Compression injuries are defined by vertebral endplates, movement of nucleus pulposus into vertebral body, osteoporosis osteoarthritis or RA

• Functional outcomes following SCI depend on motor/sensory function preserved, level of injury, and type of injury, including: age, general health prior, body build, support systems, financial security, motivation, and personality traits

• "Key Muscles by Segmental Innervation" is found on Table 12-4 page 406

• Innervation of the key muscle groups allows patients to achieve a certain amount of skill and functional independence

• A muscle must have “fair” (3/5) strength in order to perform a functional activity

• There is a review of functional potentials based on level of injury, located on Table 12-5

Classification of SCI

• Tetraplegia (quadriplegia) involves injury to the cervical region resulting in a loss of motor and/or sensory function in the UE's, LE's, trunk, and pelvis
• Paraplegia involves injury to the thoracic spine which causes a loss of motor and/or sensory function below the level of the injury and UE function is normal
• Cauda Equina Injuries are defined as injury to L1 vertebrae or below Neurological level is defined as the most caudal segment of the spinal cord with normal/intact sensory and anti-gravity motor function on both sides by dermatomes and myotomes testing
• Normal muscle function is defined by the lowest key muscle group with a grade of fair (3), as long as the key muscles above this are graded good(4) to normal(5)
• Table 12-1 lists the key muscles (American Spinal Injury Association - ASIA) consistently innervated by the designated segments of the spinal cord
• An individual may have partial innervation to up to 3 segments below the injury site
• Key muscles are:
• C5 Elbow flexors (Biceps Brachii, Brachialis)
• C6 Wrist extensors (ECRL, ECRB)
• C7 Elbow extensors (Triceps Brachii)
• C8 Finger flexors (FDP)
• T1 Finger abductors (Abductor Digiti Minimi)
• L2 Hip flexors (Iliacus, Psoas Major)
• L3 Knee extensors (Quadriceps)
• L4 Ankle dorsiflexors (Tibialis Anterior)
• L5 Big Toe extensors (EHL)
• S1 Ankle plantar flexors (Gastrocnemius)
• The ASIA Standard Neurological Classification of Spinal Cord Injury assists clinicians in assessing the extent and level of the injury
• Zone of preservation is the most caudal segment with some sensory or motor function for both and applies only to complete injuries

ASIA Impairment Scale

• Complete: sensory and motor function is absent below the injury level (S4/5)
• Grades by Impairment Scale:
• A = Complete: No motor or sensory function is preserved in the sacral segments S4-5
• B = Sensory Incomplete: Sensory but no motor function is preserved below the neurologic level and includes the sacral segments S4-5. No motor is preserved more than three levels below the motor level on either side of the body.
• C = Motor Incomplete: Motor function is preserved below the neurologic level, and more than half of key muscle functions below the neurologic level have a muscle grade less than 3/5.
• D = Motor Incomplete: Motor function is preserved below the neurologic level, and at least half of key muscle functions below the neurologic level have a muscle grade of 3/5 or more.
• E = Normal: Motor and sensory functions are normal in all segments, and the patient had prior deficits Incomplete injuries have some motor and sensory preservation below the neurological level of S4/5 and have sacral sparing
• Sacral sparing saves sacral tracts which allows perianal sensation and voluntary rectal control
• Spasticity and abnormal tone can occur
• Perianal senstation must be present for a lesion to be incomplete
• The different types of spinal cord syndromes are: Brown-Sequard, Anterior Cord, Central Cord and Posterior Cord

Spinal Cord Syndromes

• Brown-Sequard results from injury to half of the spinal cord
• Loss of motor function, proprioception, and vibration occurs on the same side of the injury, while loss of pain and temperature occurs on the opposite side of the injury a few levels below
• The prognosis is good; these patients have potential for independence with ADL's and are continent with bowel and bladder
• Anterior Cord Syndrome comes from a flexion injury to the cervical spine
• There is a loss of motor, pain and temperature sensation bilaterally, below the level of the injury
• Position sense and vibration remain intact below the level of the injury
• The voluntary motor function is lost, and this has poor prognosis
• Central Cord Syndrome is the most common incomplete injury
• This results from progressive stenosis or compression from hyperextension, bleeding into the central gray matter
• UEs are more affected, therefore causing motor impairment and variable sensory impairment
• Bowel, bladder and sexual function are preserved if the sacral portions are spared
• Independence depends on spared innervation to the UEs
• Posterior Cord/Dorsal Column Syndrome is a rare injury
• This is defined as a damage to the posterior spinal artery by a tumor or vascular infarct, loss of ability to perceive proprioception and vibration, and ability to move and perceive pain remains intact
• Cauda Equina injuries results injury are usually caused by a direct trauma from a fracture- dislocation below L1, incomplete lower motor neuron (LMN) injury and lead to flaccidity, areflexia, with loss of bowel and bladder function
• Regeneration of the involved peripheral nerve root is possible, depending on the extent of initial damage
• Conus Medullaris Syndrome is usually defined by flaccid paralysis, areflexic bowel and bladder and sacral reflexes are sometimes present

Functional Outcomes by injury level

• C1-3: Little (C3) to no (C1, C2) innervation to the diaphragm- will require mechanical ventilation, be totally dependent for ADL's requiring fulltime caregiver and will need a power w/c which can be operated chin cuff
• C4: there is Some innervation to the diaphragm and therefore may not need a ventilator, but they will need a power w/c that can be operated with a chin cup/chin control/mouth stick and should have enough neck ROM (at least 30 degrees of cervical motion), will continue to require full time caregiver because they are dependent for transfers and ADL's (maxA for bed mobility)
• C5: Innervation to deltoid, biceps brachii, brachialis, lateral shoulder rotators and rhomboids present, however may not have 5/5 strength, Should be able to flex and abduct the shoulders, flex the elbows, and adduct the scapulae which should allow the patient to: raise arms to assist with rolling and bring hands to mouth. They are Able to operate power w/c with hand control or manual w/c with rimprojections, may be indep. with some self care act's but will need set up from a caregiver
• C5: The patient will also need with adaptive equipment including splints and built up ADL devices to perform ADL's, moderate assistance for bed mobility, with Maximal assistance with sliding board or sit pivot transfer and to perform independent pressure relief by leaning forward in w/c with loops attached to back of w/c
• C6: Innervation to the wrist Ext Carpi Radialis Longus and Brevis, Pec Major (clavicular portion) and Teres Major, allows for independent rolling, feeding, and UE dressing and can propel manual wheelchair with rim projections. The patient will have Potential for independent sliding board transfers and pressure relief via weight shift side to side.
• C6: The patient may need assist in am/ pm with ADL's and with commode transfer and Assist needed for LE dressing. The patient will be able to drive a vehicle with adaptive controls and work outside the home
• C7: There is the potential to live independently and there is innervation to the triceps, latissimus dorsi and pronator teres therefore they can lift themselves up during transfers and do w/c push-up for pressure relief, They will be Able to perform self ROM on LE's
• C7: Is independent with all transfers and can be independent with transfers with and without a sliding board
• C8: Flexor carpi ulnaris, extensor carpi ulnaris, hand intrinsic innervation present, flexor digitorum profundus and In addition to all the things a C7 injury patient can perform, this patient can perform wheelies and negotiate a 2-4 inch curbs in the w/c
• T1-8: Hand intrinsics, top half of intercostals, pectoralis major (sternal portion) innervation is present and Increased motor return in thoracic region allowing for improved trunk control, posture, breathing capabilities
• T1-8: Patient will be able to transfer to the floor from w/c and be able to perform therapeutic ambulation = walking for physiologic benefits that standing and weight bearing provides
• T9-11: Abdominals innervated and in addition to the functional abilities of all of the above, these patients are able to initiate a cough and perform therapeutic ambulation with orthoses and assistive devices.
• T12-L2: There is partial innervation of the Quadratus lumborum, Iliacus, Psoas Major and they will household ambulation with orthoses and assistive devices may be possible and able to use a wheelchair for community mobility L3: A patient with presence of full Iliopsoas innervation improves their capability to ambulate, Should be independent with household ambulation with orthoses and device, be independent at community ambulation with orthoses and device, however. a KAFO will be necessary with only partial quadriceps innervation
• L4-5: Quadriceps and medial hamstrings innervation present allowing for Independence in ADL's, functional act's and gait, they will be able to ambulates (may be independent) in the community with assistive device and orthotics (AFO)
• S1-2: the plantar flexor and gluteus maximus innervation is present and Independence with all ADL's, functional act's and gait
• S1-2: The person will be able to ambulates (may be independent) in the community with or without assistive device and orthotics (articulated AFO)

Medical management and interventions for SCI

• Spinal Cord medical Injury Management includes:
• Vasopressors and mineralocorticoids for Orthostatic Hypotension
• Medications (NSAIDs, acetaminophen, gabapentin (treats nerve pain), Lyrica (treats nerve pain), analgesics), with common side effects of drowsiness, loss of appetite, dizziness, decreased coordination, upset stomach
• Treatment also includes anticoagulants, such as Coumadin/Heparin, with side effects of, severe bleeding, red or brown urine, black or bloody stool, severe headache, joint pain, swelling in the joints, dizziness and weakness, and vision changes
• SCI Prevention includes drug therapy with bisphosphonates, NSAIDs and Side Effects of Bisphosphonates, which include bone/joint/muscle pain, nausea, difficulty swallowing, heartburn, gastric ulcer
• Medical interventions can include stabilization of the spine to further spinal cord damage through surgery or through external fixation, by use of a cervical collar, or a rigid body jacket
• After stabilization, surgery is indicated in the following cases: To restore alignment of body structures, to decompress neural tissue, to stabilize the spine by fusion or instrumentation, to minimize deformities, to allow the individual earlier opportunities for mobilization
• Bony fusion occurs in 6-8 weeks
• Medical assistance include Halo Vest, Philadelphia Collar, Aspen Collar and Custom-made body jacket

Myelomeningocele (MMC), a form of spina bifida

• Myelomeningocele (definition): complex congenital anomaly that affects primarily nervous system
• Caudal end of the neural tube fails to close on the 28th day of gestation resulting in abnormal tissue growth
• Posterior vertebral arches fail to close which in turn prevents formation of spinous process Spina bifida (definition): both the bony defect and the various forms of myelodysplasia
• Spina bifida occulta: bifid spine in isolation with no involvement of the spinal cord or meninges
• Spina bifida cystica: visible cyst protruding from the opening caused by the bony defect
• Spina bifida aperta: cyst protrudes from the opening caused by the bony defect, but is covered with skin or meninges
• Meningocele: cyst is covered by meninges and contains only CSF
• Myelomeningocele: spinal cord is present in the cyst
• Anencephaly: failure of brain to develop past the brain stem, usually resulting in death
• Encephalocele: brain tissue protrudes from the skull at the occipital regions leading to visual impairments

MMC Incidence and Etiology

• The incidence of MMC is 3.4 in 10,000 live births in the U.S.
• There is a 2-3 percent risk of recurrence if a sibling was born with MMC
• The highest rate of live births with MMC is reported in China
• Correlations for MMC include genetic pre-disposure, exposure to alcohol, seizure, acne medications, obesity and lack of folic acid MMC can be diagnosed prenatally by testing for levels of alpha-fetoprotein, with high levels meaning an neural tube defect
• Correction of the defect can be performed surgically, with it commonly performed between 24-30 weeks gestation
• Neurological defects are typically motor and sensory deficits with Spinal cord that may be partially formed or malformed, where spinal cord below MMC is intact, allows potential for spastic motor paralysis and If nerve roots damaged will present with flaccid motor paralysis with lack of sensation

MMC Clinical Features with Musculoskeletal Impairments

Muscle paralysis results in lack of voluntary movement

• Common deformities include hip dislocation, subluxation with genu varus/valgus, *clubfoot, or flatfoot
• Thoracic level of lesion affects Trunk, with weakness causing Potential deformities of hips and frog-leg posture -Lesions in L1-L2 cause limited hip flexors and some adductors with Hip flexion, adduction leading to Hip Dislocation, Lumbar Lordosis and limited Knee flexion and PF -Lesions to Midlumbar in L3 affect strong hip flexors and cause weak hip rotators, antigravity knee extension leading to Hip dislocation/subluxation to Genu Recurvatum -Lesions to Low Lumbar L4 affect Strong quadriceps and medial knee flexors and will affects ankle DF and inversion which causes Equinovarus, calcaneovarus, or calcaneocavus foot -Lesions to Low Lumbar L5 affect will have impact with hip extension and can cause abduction as well with weak plantarflextion and eversion

Spinal Deformities with MMC

• Congenital scoliosis (defined) = spinal deformities related to vertebral anomalies
• Acquired scoliosis (defined) = spinal deformities caused by muscle imbalance in the trunk with flexible scoliosis, kyphosis and lordosis