Nerve and Muscular Dysfunction Flashcards
The motor branches are in what region of the spinal cord?
Anterior horn of the spinal cord
The sensory branches of the spinal cord are located where?
Dorsal root ganglion.
What is the resting potential of a nerve cell?
-70mV
Microstructure of Muscle
Z disk - marks the end of the muscle unit.
Thin filament is actin.
Thick filament is myosin.
What is cerebral palsy?
A static brain injury which gives rise to progressive musculoskeletal manifestations.
What are the different types of cerebral palsy?
- Spastic
- Athetoid
- Ataxic
- Mixed
- Hypotonic
Based on muscle tone.
Spastic cerebral palsy
Spastic cerebral palsy is the most common type of cerebral palsy. The muscles of people with spastic cerebral palsy feel stiff and their movements may look stiff and jerky. Spasticity is a form of hypertonia, or increased muscle tone. This results in stiff muscles which can make movement difficult or even impossible.
What is athetoid cerebral palsy?
Athetoid cerebral palsy also known as “dyskinetic cerebral palsy”is a movement disorder caused by damage to the developing brain. This type of cerebral palsy is characterized by abnormal, involuntary movement. Children with athetoid CP fluctuate between hypertonia and hypotonia.
What is ataxic cerebral palsy?
Usually occurs due to damage to the cerebellum resulting in Ataxia causes an interruption of muscle control in the arms and legs, resulting in a lack of balance and coordination.
What is hypotonic cerebral palsy?
Hypotonic
Explain the anatomical distributions of CP.
- Hemiplegic
- Diplegic - where the legs are affected much more than the arms.
- Quadriplegic - 4 limbs
- Total body - loss of control of head as well.
What scale plays a large role about whether intervening with surgery is necessary for a kid with cerebral palsy?
Gross Motor Function Classification Scale
What can cause cerebral palsy?
Prematurity Anoxic brain injury Perinatal infection Meningitis Brain malformations Brain trauma
What are the orthopaedic manifestations of cerebral palsy?
Contractures
Fractures
Upper limb deformity
Hip dislocation
Spinal deformity – scoliosis
Foot deformities
Gait problems
What are contractures and why do they present in CP?
Contractures refer to the permanent tightening of tissues. This includes muscles, tendons, ligaments, or skin. It makes it hard or impossible to move the nearby joints.
Contractures present in CP because the skeleton grows normally but the muscles do not recieve normal stimulation to grow.
Why are children with CP succeptible to fractures?
CP children don’t weight bare so they are very osteopenic and they bones aren’t as strong.
What are the foot deformities seen in CP children?
Varus and valgus deformities of the foot arch.
How does the normal spastic posture of upper limb present?
Flexion at the elbow and flexion at the wrist.
Clasp hand.
What are the two X-linked muscular dystrophies?
Duchenne’s Muscular dystrophy
Becker’s muscular dystrophy
Duchenne Muscular Dystrophy
Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact.
Which gene becomes non-functional in DMD?
Dystrophin gene
Who does DMD affect!?
3/1000 males at birth.
- X-linked
How does DMD present?
Presents at 4yrs with clumsy walking followed by difficulty standing and respiratory failure.
Pseudohypertrophy in calves (due to adipose deposition).
Scoliosis - rapidly advancing in DMD.
Joint contractures.
Cardiomyopathy.
Static encephalopathy.
Gower’s sign.
What is Gowers sign?
The child assumes the hands-and-knees position and then climbs to a stand by “walking” his hands progressively up his shins, knees, and thighs. This maneuver, known as Gowers’ sign, has been associated almost exclusively with Duchenne’s muscular dystrophy.
What is the prognosis for someone with Duchenne Muscular Dystrophy.
Unable to walk without crutches by 10
Wheelchair by 15
Most die of cardiomyopathy by 20
Respiratory failure
What is Beckers MD?
A milder form of Duchennes, where dystrophin is reduced but present.
Later onset and a slower progression.
How is DMD treated?
Steroids prolong ambulation.
Pulmonary care
Physio
Bracing
Surgery for scoliosis
