OCT 5232C: Peripheral Region Brain Stem

Introduction

• Learning Objectives:
  • Identify the location, relationship, and function of peripheral nerves with respect to the CNS.
  • Compare causes, pathologies, and prognoses of different neuropathies and their effect on occupation.
  • Differentiate between motor, autonomic, and somatosensory signs and symptoms associated with peripheral and CNS lesions.

Peripheral Nerves

• Definition: All neural structures distal to spinal nerves and cranial nerves outside the skull.
• Connective Tissue Sheaths:
  • Epineurium: Encloses the entire nerve trunk.
  • Perineurium: Surrounds fascicles.
  • Endoneurium: Separates individual axons.
• Functionality:
  • Posterior rami innervate structures along the posterior midline.
  • Anterior rami innervate anterior and lateral body structures.
  • Supply can be to viscera or somatic structures (mixed nerves).

The Plexuses

• Cervical Plexus: Cutaneous sensation from the posterior scalp to clavicle.
• Brachial Plexus: Formed by anterior rami of C5 to T1, innervates the entire arm.
• Lumbar Plexus: Formed by anterior rami of L1 to L4, innervates anterior and medial thigh.
• Sacral Plexus: Formed by anterior rami of S1 to S4, innervates posterior thigh and most of the leg and foot.

Movement and Nerve Health

• Importance: Movement promotes nerve health by enhancing blood and axoplasm flow.
• Mechanisms:
  • Axoplasm thinning.
  • Facilitates anterograde and retrograde transport.

Dysfunction of Peripheral Nerves

• Sensory Changes:
  • Hyperalgesia, dysesthesias, paresthesia, allodynia.
• Motor Changes:
  • Paresis or paralysis indicated by EMG recordings.
• Autonomic Changes:
  • Lack of sweating, sympathetic control loss, resulting in edema.
• Trophic Changes:
  • Muscle atrophy, shiny skin, brittle nails, poor wound healing.

Classification of Neuropathies

• Traumatic Myelinopathy: Demyelination, often rapid recovery.
• Traumatic Axonopathy: Axonal damage, slower recovery.
• Severance: Slow recovery with poor results.
• Multiple Mononeuropathy: Often due to diabetes or inflammation.
• Polyneuropathy: Associated with diabetes, autoimmune disorders, hereditary conditions.

Clinical Assessment and Intervention

• Assessment: Reflex, motor, sensory, coordination.
• Evaluation: Provocative testing, standardized assessments for IADL and ADL skills.
• Interventions:
  • Education to prevent complications.
  • Daily visual inspection for individuals with affected sensation.
  • Edema management, contracture prevention, endurance exercise.
  • Use of orthoses for stabilization and functional improvement.

Conclusion

• Peripheral nerve lesions show symptoms in nerve distribution.
• Importance of normal stretching and shortening for nerve health.
• Effects can range from mononeuropathy to polyneuropathy, impacting sensory and motor functions.

References

• Lundy-Ekman, L. (2022). Peripheral region. In Neuroscience fundamentals for rehabilitation (pp. 298-325). Elsevier Publishing.