Cervical Lecture 4: Clinical Instability, Cervicogenic Dizziness, and Peri-Operative Considerations

Vocabulary terms and definitions covering cervical clinical instability, cervicogenic dizziness theories, and post-operative management protocols for common cervical surgeries.

Mechanical Instability

Instability specifically involving the passive subsystem of the cervical spine.

Clinical Instability

The lack of neuromuscular control or muscular function to control movement between the opposite ends of the stability afforded by the passive subsystem; interpreted as the ability to actively control the passive movement available.

Passive Subsystem

Components such as discs, ligaments, and bony structures that provide inherent mechanical stability; these may be affected by degenerative changes, trauma, or repetitive forces.

Active Subsystem

The muscular system, specifically the deep stabilizer muscles, responsible for maintaining stability through strength, recruitment, and endurance.

Neural Subsystem

The control mechanism responsible for motor recruitment and coordination of the active subsystem to maintain stability.

Cook 2005 Delphi study findings

A study identifying clinical findings for instability including intolerance to static postures, head feeling heavy, relief with external support, and aberrant movement during AROM.

Cervicogenic Dizziness (CGD)

Symptoms of light-headedness, unsteadiness, or being off-balance (not true vertigo) usually resulting from the upper cervical spine.

Cervico-collic Reflex (CCR)

A reflex where cervical muscles react in response to stretch to help stabilize the head on the body.

Cervico-ocular Reflex (COR)

A reflex that complements the VOR to stabilize vision, which may play a larger role in the presence of vestibular loss.

Altered Somatosensory Input Hypothesis

The prevailing theory to explain CGD, where cervical dysfunction results in a sensory mismatch between cervical, vestibular, and visual inputs.

Anterior Cervical Discectomy and Fusion (ACDF)

An antero-lateral surgical approach where a disc is removed and replaced with autograft or allograft bone to stabilize the segment.

Laminectomy

A posterior surgical approach typically indicated for spinal stenosis where the lamina is resected on one or both sides.

Foraminotomy

A less invasive surgical procedure involving trimming to widen the intervertebral foramen; stability is generally maintained as facet joints are mostly preserved.

Maximum Protection Phase (Phase 1)

The initial post-operative period spanning $0-14$ days focused on protecting the surgical repair, decreasing pain/edema, and increasing ambulation.

Controlled Movement Phase (Phase 2)

A post-operative period spanning days $15-21$ where goals include improving ADLs and UE flexibility while keeping elevation below $90^\text{o}$.

Reparative Phase (Phase 3a)

A period spanning $4-8$ weeks where PT commonly starts, focusing on nerve healing, scar tissue prevention, and increasing thoracic mobility.

Return to Function Phase (Phase 3b)

A period spanning $9-12$ weeks focused on restoring cervical functional ROM and strengthening cervical extensors.

Return to Function Phase (Phase 3c)

The final post-operative phase spanning $13-52$ weeks aimed at maximizing function and restoring workplace or sport-related strength and endurance.