Peripheral Nerve Injuries and Regeneration

Vocabulary flashcards covering types of neuropathy, connective tissue layers, Sunderland classification, neuronal injury responses, and peripheral nerve regeneration processes.

Simple Mononeuropathy

Isolated involvement of a single peripheral nerve, such as radial nerve injury following a humerus fracture.

Multiple Mononeuropathy

Involvement of two or more peripheral nerves individually and generally asymmetrically.

Polyneuropathy

Simultaneous and generally symmetrical involvement of numerous nerves, frequently affecting hands and feet.

Endoneurium

Connective tissue layer that individually surrounds each axon, whether myelinated or unmyelinated.

Perineurium

Connective tissue layer that surrounds and protects nerve fascicles.

Epineurium

Outer connective tissue layer that envelopes the entire nerve.

Mesoneurium

Connective tissue related to the mobility and relationship of the nerve with surrounding structures.

Neuropraxia (Sunderland Grade I)

Conduction alteration while maintaining axon continuity; general prognosis is very favorable with usually spontaneous recovery.

Axonotmesis (Sunderland Grade II)

Interruption of the axon and myelin while conserving the endoneurium; favorable prognosis as endoneural tubes guide regeneration.

Sunderland Grade III Injury

Injury to axon and endoneurium with preserved perineurium and epineurium; prognosis is variable and regeneration is more difficult.

Sunderland Grade IV Injury

Damage to the axon and internal structures while mainly preserving the epineurium; unfavorable prognosis that may require specialized intervention.

Neurotmesis (Sunderland Grade V)

Complete loss of continuity of the nerve and its coverings; unfavorable prognosis usually requiring surgical repair.

Wallerian Degeneration

Process occurring in the segment distal to the lesion site involving axon disintegration, myelin degradation, and macrophage infiltration.

Chromatolysis

Neuronal cell body response in which its size increases and the nucleus moves to the periphery.

Bands of Büngner

Structures formed by Schwann cells that orient growth cones of the axon toward the distal stump.

Peripheral Regeneration

Axonal repair process that is most efficient when guiding structures are preserved, especially endoneural tubes and the basal lamina.

Schwann Cells

Cells fundamental to peripheral nervous system regeneration that provide basal lamina and guiding structures to facilitate axonal growth and form bands of Büngner.

Myelinopathy

Nerve condition where main damage is localized in the myelin sheath, classically exemplified by the demyelinating form of Guillain-Barré syndrome.

Axonopathy

Nerve condition where main damage is localized in the axon, which can lead to distal degeneration and require axonal regeneration.

Longitudinal Irrigation

Blood supply to peripheral nerves that provides oxygen and nutrients needed to maintain nerve function and support repair processes.