Spasticity in Cerebral Palsy Pathophysiology to practice

1. Spasticity in Cerebral PalsyPathophysiology to practice By: Hamidah Lalani, BSN, RN. Graduate Student Alverno College

2. Objectives • The learner will be able to: • Understand the functions of upper motor and lower motor neurons • Learn definition, epidemiology and causes of Cerebral Palsy (CP). • Understand the pathophysiology of spasticity as it relates to Cerebral Palsy.

3. Objectives • Understand the role of inflammatory immune response in spasticity. • Understand the role of stress response in spasticity • Identify patients needs and nursing outcomes in caring for the patient with spasticity.

4. Instructions for tutorial • Read the information carefully followed by the question and possible answers. Click on the answer you think is correct. If you want to go back to the previous slide click on the button. If you want to go to next question click on the bottom left corner of the slide. If you want to start over click on the button.

5. Cerebral Palsy • It is the disorder of movement and posture that result from a non-progressive lesion or injury of the immature brain. • Leading cause of childhood disability

6. Cerebral Palsy • Occurs in 2 to 3 per 1000 live births. • Causes: prenatal, perinatal, and postnatal. • 765,000 Americans have CP • 9000 children are diagnosed each year • 1 in 3 with very low birth weight will be diagnosed with CP http://www.ucp.org/ucp_generalsub.cfm/1/9/1217

7. Upper and Lower motorneuron Upper motorneuron Injury to UMN leads to hypertonia. Elicit deep tendon reflex Dorsal horn cell in spinal column carry information to the brain and are also called afferent nerve fibers or input association (IA). Lower motorneuron Injury or lesion to LMN results in hypotonia. Have negative reflexes. Ventral horn cells in spinal column bring information to the muscle fibers and are also called efferent nerve fibers or output association (OA).

8. The information sent to the brain as input association through the spinal cell column from the muscles goes through: Dorsal Horn Ventral Horn

9. Right! • The dorsal horn is the input association that brings information from the spinal column to the brain.

10. Really? • The ventral horn brings information to the muscle fiber.

11. Cerebral palsy is associated with spasticity

12. What is Spasticity? • Velocity-dependent increase in muscle tone with exaggerated tendon reflexes, due to hyper excitability of stretch reflex.

13. Causes • Spasticity can be caused by any insult to the brain related to: • Trauma • Abuse • During birth • Birth defect • Genetically acquired • Secondary to other disease, e.g. encephalitis, hydrocephalus, MS, spinal dysreflexia, stroke.

14. Pathophysiology • With any brain lesion, communication from the brain is disrupted and the brain is unable to inhibit the stretch reflex. • In case of injury to the cortex the inhibitory signals are lost and the person experiences hyperactivity or spascity.

15. http://128.104.8.50/courses/neuro/SClinic/Weakness/lmn98.JPG

16. Spasticity • A lag time may exist between injury and spasticity onset • Severity may wax and wane over time and vary by diagnosis. • Spasticity may be static (always present) or dynamic (increase with intentional movement) in nature.

17. Stress in Spasticity • Increased activity of the reticular activating system (RAS) and its influence on reflex circuits that controls the muscle tone causes increased tension in the muscle that adds to already tight muscles.

18. Factors effecting stress in spasticity • Genetic predisposition • Age • Sex • Exposure to environmental stimuli • Life experiences • Diet • Social support

19. Stress and Immunity • Immune response is triggered by stress. • Immunity is also compromised in stress due to increased levels of cortisol.

20. Inflammatory immune response In the event of an inflammatory immune response, the brain cells including neurons produce broad spectrum inflammatory mediators like CRP and cytokines IL-1B and IL6 that can cause tangles and plaques which could in turn cause neuronal loss and ultimately loss of movement.

21. In inflammatory immune response, tangles and plaques are formed due to the mediators like: CPK IL- IB, IL- 6 CPK IL- 6 CPK IL- IB

22. Right! • CPK, IL IB and IL 6 are the inflammatory immune mediators.

23. Wrong • IL – 6 is also involved in the inflammatory response.

24. Wrong • IL – IB is also involved in the inflammatory immune response.

25. In the event of stress, muscle tension is increased due to the increased activity of: Reticular activating system Cortical releasing factor

26. Right! • RAS increases muscle tension in stress.

27. Wrong! • Cortical releasing factor (CRF) works synergistically with cortisol to inhibit the function of immune system.

28. The synapses that send nerve conduction to upper extremities are from C5 (cervical) to C8. • The L2 (lumbar) to S1(sacral) segments are responsible for nerve conduction to lower extremities.

29. Case Study • A three year old girl with a history of shaken baby syndrome came to clinic with complaints of not meeting her developmental stages. A MRI of the spine revealed injury at L3 level of the vertebrae. The injury has affected her: Arms Legs

30. Right! • Legs are affected if the injury is between L2 and S1.

31. wrong • Injury between C5 and C8 affects arms.

32. It was determined during the physical examination and history from her guardian that she cannot walk. The tone in her legs was increased and she had spasticity. The injury therefore is in: Upper motorneuron Lower motorneuron

33. Right! • Upper motorneuron causes the hypertonia or spasticity.

34. Wrong! • Injury to lower motorneuron causes weakness or hypotonia.

35. Neuromuscular Junction http://en.wikipedia.org/wiki/Neuromuscular_Junction

36. Acetylcholine a neurotransmitter,released at the synaptic junction binds itself to the cholinergic receptors in the post synaptic terminal and provide information to the skeletal muscle. • Cholinergic receptors are of two types: nicotinic and muscarinic. Nicotinic are found in the skeletal muscles and helps with receiving acetylcholine.

37. Acetylecholine binds with cholenergic receptors in the post synaptic junction to provide information for contraction to the skeletal muscle. Acetylecholine is a: Neurotransmitter Synapse Receptor

38. Right! • Acetylecholine is the neurotransmitter participates in the contraction of the skeletal muscle.

39. Really? • A synapse helps with action potential in neurons and muscles.

40. Wrong! • A receptor like cholinergic receptor attaches to the (acetylecholine) neurotransmitter to initiate the muscle contraction.

41. What is Muscle tone? It is the tension in a muscle caused by the passive movement of the joint and it is very important for the muscle movement. Intrafusal muscle fibers lengthens the the muscle. Extrafusal muscle fibers contracts the muscle.

42. Muscle Spindle http://en.wikipedia.org/wiki/File:Skeletal_muscle.jpg

43. Tonic reflexes are polysynaptic and help with movement and tone of the muscle through the descending excitatory signals from brain. • Phasic reflexes are monosynaptic and exhibit reflexes like deep tendon reflex.

44. When the neurotransmitter reaches the post synaptic terminal Intrafusal muscle fibers get the information to: Stretch the muscle Contract the muscle

45. Right! • The intrafusal fiber is responsible for lenghtening the muscle fiber .

46. Wrong! • The extrafusal muscle is responsible for muscle contraction.

47. Case study • A fifteen year old girl with a history of premature twin birth and diagnosed with cerebral palsy came to clinic. On physical examination, the doctor was unable to elicit knee jerk reflex. Which pathway is interrupted? Tonic excitatory Phasic excitatory

48. Right! • Phasic excitatory pathway effects all reflexes.

49. Wrong! • Tonic excitation effects the movement and contraction of the muscle like extention and flexion of the arm.

50. Both her arms were stretched out and the doctor was unable to flex them. Which of the following pathways was interrupted? Descending excitatory Descending inhibitory