This document discusses assessment methods for peripheral nerve surgery outcomes. It describes qualitative and quantitative nerve function assessment methods and their limitations. Electrodiagnosis plays an important role in nerve injury evaluation by localizing injury sites and distinguishing conduction block from axonal degeneration. Sensibility, motor function, pain and activities of daily living are important outcomes to assess. Factors like age, cognitive capacity, injury timing and type influence recovery. Nerve conduction studies and electromyography are essential to evaluate peripheral nerve disorders.

1. Assessment of peripheral nerve surgery

2. At the end of the lecture the participant
will be able to:
• 1. List the qualitative and quantitative
methods for nerve function understanding
their limitations
• 2. Understand the role of electro diagnosis in
nerve injury

3. Issues & Challenges
• cortical functional reorganization of hand representation
result of axonal misdirection - cortical remapping
• Modulation of central nervous processes rather than
peripheral factors
• Brain capacity for visuo-tactile and audio-tactile interaction
• selective de-afferentation enhancing the effects of sensory
relearning
• no surgical technique which can ensure recovery of tactile
discrimination in the hand of an adult after median nerve
lesion
• hand as a sense organ
• MRC Scale subjective findings - psychometric drawbacks

4. Regeneration after nerve repair
regardless of the repair technique - axonal
misdirection is unavoidable

5. Assessment of hand function
• sensibility
• motor function
• autonomic
• pain and
• discomfort

6. Model Instrument for Outcome
After Nerve Repair
• Detection tests - Semmes-Weinstein monofilaments,
• discrimination tests - two-point discrimination (2PD),
• identification tests- shape/texture-identification (STI) test
• activities of daily living (ADL) - The DASH was also the
most commonly used condition-specific patient-reported outcome in the
included clinical trials
• (McPhail, Bagraith, Schippers, Wells, & Hatton, 2012)

7. Factors influencing the outcome
• Age
• Cognitive brain capacities - Verbal learning capacity and
visuo-spatial cognitive capacity
• Timing of repair
• Type of nerve
• Level of injury
• Type of injury
• role of the brain in functional recovery - ‘new
language spoken by the hand’.

8. What happens in the brain after nerve
injury and repair
• silent ‘black hole
• adjacent cortical areas expand and occupy the
former
• distorted discontinuous islands

9. Sensory re-education and sensory
relearning
• mind does not understand the new ‘sensory
code’ associated with specific textures and
shapes
• touch modalities, localise touch, shapes and
textures
• concepts of learning mechanisms, cortical
remodelling and brain plasticity

10. New strategies in sensory re-education
and sensory relearning
• Phase 1: maintaining the cortical hand map
activate the cortical area representing the damaged nerve- visuo-tactile and
audio-tactile interaction
• Activation of motor neurones – ‘mirror neurones’ in premotor
cortex by the mere observation of hand motor actions
• activated by reading/listening to action or words
• Phase 2: enhancing the effects of sensory re-
education
de-afferentation of the forearm would hypothetically result in
expansion of the adjacent cortical hand representation
• Cutaneous de-afferentation of the forearm
(Rizzolatti et al. 2001, Rizzolatti & Craighero 2004)

13. Outcomes
• outcome shows ongoing improvements up to
5 years after the nerve repair
• 59% of patients with median or ulnar nerve
repairs returned to work within 1 year with an
average time off work of 31 weeks (Jaquet 2004)
• high education, high compliance to hand
therapy and an isolated injury predict quicker
return to work in patients with median and/or
ulnar nerve injuries.

14. Sollerman Hand Function Test
• overall measure of hand and grip function when
engaging in ADLs (Sollermen & Ejeskar 1985).
• It was designed to measure grips that are needed
for certain ADLs such as eating, driving, personal
hygiene, and writing.
• includes subtests that represent common
handgrips (volar, transverse volar, spherical volar
and pinch positions - pulp, lateral, tripod, and the
five finger) and activities (using a key; picking up
coins from a flat surface; writing with a pen; using
a phone; and pouring water from a jug)

16. Nerve Conduction Studies and
Electromyography in the
Evaluation of Peripheral Nerve Injuries

17. NCS & EMG
• essential in the evaluation of nerve disorders
• localizing the site of injury
• distinction of conduction block from axonal
degeneration
• prognostic information
• dependent on the skills of the examiner
• Augment physical examination

18. NCS and Needle EMG
• measurement of nerve response amplitude
and conduction velocity along the course of
each nerve
• sensory nerve action potential (SNAP) 5–20
mV in amplitude
orthodromically/antidromically
• compound motor action potential (CMAP)
• Needle EMG distinguish neurogenic /
myopathic causes

20. Post Injury - acute
• Motor axons remain excitable for up to 7 days
after injury. Sensory axons to 11 days
• So perform 14 days post injury
• Spontaneous activity in muscles - 2 – 6 weeks

24. References
• Lundborg G, Rosén B. Hand function after nerve repair. Acta Physiologica February
2007;189(2):207-217
• McPhail, S. M., Bagraith, K. S., Schippers, M., Wells, P. J., & Hatton, A. (2012). Use
of Condition-Specific Patient-Reported Outcome Measures in Clinical Trials among
Patients with Wrist Osteoarthritis: A Systematic Review. Advances in orthopedics,
2012,
• Jaquet, J. 2004. Median and minor nerve injuries: Prognosis and predictors for
clinical outcome. Thesis. Department of Plastic and Reconstructive Surgery,
Erasmus Medical Center, Erasmus University, Rotterdam