1. Module 3b: NERVE FUNCTION IMPAIRMENT Module 3b: NERVE FUNCTION IMPAIRMENT

2. Nerve Function Impairment (NFI) is a loss or abnormality of the nerve’s sensory, motor and/or autonomic functions as a result of damage to its anatomic structure.

3. NFI occurs when: 1.The nerve is overloaded with and destroyed by infiltrating M. leprae. Numerous acid-fast bacilli in globi formation (Fite Faraco stain).

4. NFI occurs when: 1.The nerve is overloaded with and destroyed by infiltrating M. leprae. 2.The body’s immune system recognizes the M. leprae antigen inside the nerve and proceeds to attack, thereby damaging the nerve in the process. 3.The load of bacilli in untreated lepromatous cases can be so high that the nerve is destroyed by the sheer density of bacteria & their metabolic products. 1.The nerve is overloaded with and destroyed by infiltrating M. leprae. 2.The body’s immune system recognizes the M. leprae antigen inside the nerve and proceeds to attack, thereby damaging the nerve in the process. 3.The load of bacilli in untreated lepromatous cases can be so high that the nerve is destroyed by the sheer density of bacteria & their metabolic products.

5. NFI usually happens in the dermal or cutaneous nerves, which are fine nerves that innervate the skin throughout the body. It is for this reason that skin lesions in leprosy have a decrease or loss of sensation, sweating and loss of hair.

6. STAGES OF NERVE INVOLVEMENT: Time Frame Manifestations of NFI Present for less than 12 months. Nerve may be tender. Decreased sensation. Muscle weakness. Skin dryness. Nerve may be tender. Decreased sensation. Muscle weakness. Skin dryness. Interventions Prednisone treatment. Splinting. Active exercises for weak muscles. Care of skin. Prednisone treatment. Splinting. Active exercises for weak muscles. Care of skin. Silent Neuritis

7. STAGES OF NERVE INVOLVEMENT: Time Frame Manifestations of NFI Present for less than 6 months. Enlarged, painful nerve. Loss of protective sensation. Muscle weakness & atrophy Skin dryness. Enlarged, painful nerve. Loss of protective sensation. Muscle weakness & atrophy Skin dryness. Interventions Prednisone treatment. Splinting. Active exercises for weak muscles. Care of skin. Nerve decompression. ADL Prednisone treatment. Splinting. Active exercises for weak muscles. Care of skin. Nerve decompression. ADL Acute Neuritis

8. STAGES OF NERVE INVOLVEMENT: Time Frame Manifestations of NFI Present for more than 12 months. Fibrotic nerve. Anesthesia. Muscle paralysis. Dry, cracked skin. Recurrent ulcers, bone loss, stiff joints & other deformities. Fibrotic nerve. Anesthesia. Muscle paralysis. Dry, cracked skin. Recurrent ulcers, bone loss, stiff joints & other deformities. Interventions Care of skin. Straightening exercises for stiff joints. Wound care. Reconstructive surgery. Care of skin. Straightening exercises for stiff joints. Wound care. Reconstructive surgery. Chronic Nerve Damage

9. Within 12 months (Golden Period) to prevent development of permanent nerve damage and a lifetime of disabilities, deformities and their subsequent psychological effects. It is very important to detect the early signs of NFI. !

10. ! Beyond the “Golden Period”, nerve damage becomes irreversible. The earlier the detection & intervention, the greater the chance of reversing nerve impairment (2-3 months for facial nerve, less than 6 months for other nerves).

11. Affected Nerves & Resultant Impairments: EYE: Nerve Area of Function Facial Sensory Autonomic Motor Eye closure -- Positive (+) NFI Primary Impairment Secondary Impairment Lid gap Eye redness, corneal ulcers, blurring of vision, blindness

12. Affected Nerves & Resultant Impairments: EYE: Nerve Area of Function Trigeminal Sensory Autonomic Motor -- Corneal sensation -- Positive (+) NFI Primary Impairment Secondary Impairment Corneal anesthesia Eye redness, corneal ulcers, blurring of vision, blindness

13. Affected Nerves & Resultant Impairments: HAND: Positive (+) NFI Primary Impairment Secondary Impairment Partial / complete loss of sensation, skin dryness, muscle weakness / paralysis (mobile clawing) Ulcers & injuries, skin cracks, infection, bone loss, stiff joints, deformities. Nerve Area of Function Ulnar Small muscles of the hand Sensory Autonomic Motor Medial 1/3 of the hand

14. Affected Nerves & Resultant Impairments: HAND: Positive (+) NFI Primary Impairment Secondary Impairment Partial / complete loss of sensation, skin dryness, muscle weakness / paralysis (mobile clawing) Ulcers & injuries, skin cracks, infection, bone loss, stiff joints, deformities. Nerve Area of Function Median Thumb movements Sensory Autonomic Motor Lateral 2/3 of the palm

15. Affected Nerves & Resultant Impairments: HAND: Positive (+) NFI Primary Impairment Secondary Impairment Partial / complete loss of sensation, skin dryness, muscle weakness / paralysis (wrist drop) Ulcers & injuries, skin cracks, infection, bone loss, stiff joints, deformities. Nerve Area of Function Radial Wrist extension Sensory Autonomic Motor Lateral 2/3 of hand (dorsal) Lateral 2/3 of hand

16. Affected Nerves & Resultant Impairments: FOOT: Positive (+) NFI Primary Impairment Secondary Impairment Partial / complete loss of sensation, skin dryness, muscle weakness / paralysis (foot drop) Ulcers & injuries, skin cracks, infection, bone loss, stiff joints, deformities. Nerve Area of Function Common Peroneal Foot up Sensory Autonomic Motor Dorsum of foot

17. Affected Nerves & Resultant Impairments: FOOT: Positive (+) NFI Primary Impairment Secondary Impairment Partial / complete loss of sensation, skin dryness, muscle weakness / paralysis (clawed toes) Ulcers & injuries, skin cracks, infection, bone loss, stiff joints, deformities. Nerve Area of Function Posterior Tibial Small muscles of the foot Sensory Autonomic Motor Sole of foot

18. Primary impairments are due to the direct bacillary infiltration of body structures (skin, nerve trunks, eyes.) Secondary impairments result from neglect or inappropriate management of primary impairments.