lower motor neuron lesion (LMNL)

lower motor neuron lesion (LMNL)
BELLS PALSY AND FACIAL PALSY

1. HAFSA KHALID LAIBA ROOP PAUL AQSA MUSHTAQ MARYAM KHALID LAREB SATTAR SABIHA MANZOOR NOOR FAIZA GROUP MEMBERS:

2. lower motor neuron lesion

3. Motor system The motor system is the part of the central nervous system that is involved with movement. It consists of : P yramidal and extrapyramidal system tracts from UMN & LMN 

4. A motor neuron is a nerve cell (neuron) whose cell body is located in the spinal cord and whose fiber (axon) projects outside the spinal cord to directly or indirectly control effector organs, mainly muscles and glands. Motor neurons' axons are efferent nerve fibers that carry signals from the spinal cord to the effectors to produce effects. Motor Neuron

5. Types of motor neurons There are two t ypes of motor neurons: Upper motor neuron Lower motor neuron

6. Upper motor neurons  (UMNs) are  motor neurons  that originate either in the  motor  region of the cerebral cortex or in the brain stem and carry  motor  information down to the lower  motor neurons .

7. LOWER MOTOR NEURON are neurons whose cells bodies are located in either the ventral (anterior) horn of the spinal cord gray matter and in the  motor  nuclei of the cranial nerves in the brainstem.

8. All voluntary movement depend upon excitation of lower motor neuron by upper motor neuron . These are the only neurons that innervate the skeletal muscle fibers, they function as the final common pathway, the final link between the CNS and skeletal muscles

9. A lesion is any abnormal damage or change in the tissue of an organism, usually caused by disease or trauma. Lesion is derived from the Latin word laesio meaning injury. What is Lesion ?

10. Lower motor neuron lesion  Destruction of motors which supply the muscles. It starts from anterior horn cell ends at the muscles.

11. Classification of lower motor neurons Lower motor neurons are classified based on the type of muscle fiber they innervate: Alpha motor neurons ( α- MNs ) Gamma motor neurons ( γ- MNs)

12. Alpha motor neurons ( α- MNs) Alpha motor neurons ( α- MNs) innervate extra fusal muscle fibers, the most numerous type of muscle fiber and the one involved in muscle contraction.

13. Gamma motor neurons ( γ- MNs) Gamma motor neurons ( γ- MNs) innervate intrafusal muscle fibers, which together with sensory afferents compose muscle spindles. These are part of the system for sensing body position (proprioception)

14. Destruction in the anterior horn cell : Poliomyelitis, motor neuron diseases Motor nerve (peripheral) is affected : Traumatic stress, peripheral neuropathy. Abnormal stimulation at Neuromuscular junction : Myasthenia gravis Myomatous for muscles : Neoplasm " Truma “, muscular dystrophies. Causes of lmnl

15. 1- Motor affection: 2- Reflex affection in LMNL : 3- Reaction of degeneration ( Electric current ): Features and manifestations of lmnl

16. 1- Motor affection : Flaccid paralysis : Defection in the muscle. Loss of ability to a body part. Muscle wasting : Atrophy in the muscle due to losing of muscle function (Muscle can not contract voluntary but reflex). Atonia : complete loss of muscle tone as the nerve fibers is affected. Facial nerve: it affects one half of face .(Bells palsy)

17. Bell's palsy Bell's palsy  is a condition in which the muscles on one side of your face become weak or paralyzed. It affects only one side of the face at a time, causing it to droop or become stiff on that side . It's caused by some kind of trauma to the seventh cranial nerve. This is also called the “facial nerve.”

18. ELECTROTHERAPY IN BELLS PALSY: The electrotherapy modalities included: Electrical stimulation (ES), Ultrasound , Electromyography

19. No evidence support electrical stimulation benefit for acute facial paralysis but it's effective for chronic condition Ultrasound can be beneficial for acute conditions

20. 2- Reflex affection in LMNL : Deep reflex : Loss of deep reflex. S uperficial reflex : still going if the muscle isn’t affected. Bibinski sign is negative. Absence of tonic neck reflex

21. Tonic neck reflex Fencing posture   When newborn lie on their backs, their head usually turn to one side or the other . The arm and the legs on the side toward which the head turns extend, and the opposite arm and leg contract . This is also called the boxer or fencing reflex . The reflex disappears between the second and third months of life

22. 3- Reaction of degeneration (Electric current ): Prolonged chronaxie "Time to get stimulation“ Respond to faraday current only without galvanic current . Fibrillation : Irregular unorganized invisible spontaneous contraction of muscle.

23. 3. Fasciculation : Irregular unorganized visible spontaneous contraction of muscle. 4. Anodal closure contraction IS BIGGER THAN cathode closure contraction

24. Fasciculation

25. Anodal closure contraction IS BIGGER THAN cathode closure contraction

26. SUMMARY Flaccid paralysis Dec. tone, focal muscle atrophy Focal muscle weakness Dec. or absent reflexes Fasciculations