Peripheral nervous system conditions

Peripheral nerve injuries

Injuries to the peripheral nerves due to trauma, chronic traction, compression, or shear.

Definitions

Wallerian degeneration

Degeneration of the axon and myelin sheath distal to the site of an axonal interruption.

Neuropathy

Degenerative changes in peripheral nerves that produce loss of motor and sensory function; caused by diabetes, nutritional deficits, or alcohol use.

Mononeuropathy

Degeneration of a single nerve.

Polyneuropathy

Bilateral, symmetrical involvement of peripheral nerves, typically in stocking/glove distribution.

Neuropraxia

Injury to a nerve causing sudden loss of function (compression injury); dysfunction can be rapidly reversed or persist for weeks.

Axonotmesis

Injury to a nerve interrupts the axon and causes loss of function and degeneration distal to the lesion (crush injury); regeneration is possible with or without surgical intervention.

Neurotmesis

Complete severance of the nerve, resulting in total loss of function; reinnervation fails without surgical intervention.

Entrapment syndrome

Pressure on a nerve where it passes through an opening or over a bony prominence.

Myasthenia gravis

Definitions

Myasthenia gravis

An autoimmune disorder leading to decreased acetylcholine receptors at the neuromuscular junction, and thus a decrease in muscular contraction with repetition.

Symptoms

• Muscle weakness, especially in the eyes, face, throat, and limbs
• Double vision
• Drooping eyelids
• Difficulty swallowing or speaking
• Weakness that worsens with activity and improves with rest

Definitions

Myasthenia crisis

Occurs when the exacerbation of symptoms progresses to the respiratory system, leading to life-threatening weakness.

Interventions for myasthenia gravis

• Energy conservation techniques are the goal of the sessions
  • No strength training as the patient becomes more fatigued with increased repetition of activity
• Attempt to conduct therapy sessions in the morning to decrease fatigue
• Avoid thermal modalities such as heat packs, whirlpool, etc.

Bell’s palsy

Definitions

Bell’s palsy

A lower motor neuron lesion involving cranial nerve VII (facial nerve), causing unilateral facial paralysis due to acute inflammation of unknown etiology, resulting in compression of the nerve in the temporal bone.

Symptoms peak within the first few hours or days and typically last for several weeks to months.

Symptoms

• Facial droop on one side of the face
• Drooling from one side
• Loss of taste to the anterior 2/3 of the tongue
• Changes in saliva and tear production
• Headache
• Loss of sensation to the anterior two-thirds of the tongue
• Sensory to face remains intact

Interventions for Bell’s palsy

• Spontaneous recovery can occur
• Corticosteroid use for inflammation
• Electrical stimulation for nerve stimulation
• Exercises for facial muscles
• Taping of the eyelid to prevent dry eye due to the inability to close the eyelid

Guillain–Barré syndrome (GBS)

Definitions

Guillain–Barré syndrome (GBS)

An acute autoimmune disorder in which the myelin sheath of peripheral nerves is damaged. It typically occurs after recovery from a viral illness, causing demyelination of both cranial and peripheral nerves.

Symptoms

• Causes motor and mild sensory loss distal to proximal in a symmetrical pattern
• Usually begins in the legs and will ascend towards the trunk and upper extremities (UE)
• Worse prognosis if the disease progresses to the lungs, requiring mechanical ventilation
• Motor/sensory loss progressively worsens over a 4-week period and then stabilizes

Interventions for Guillain–Barré syndrome (GBS)

• Sessions focus on compensatory strategies to assist with gait and mobility
• Avoidance of overstretching and overuse during acute phases of diagnosis
• Strength training is performed once stabilization of the disease process occurs, with progression from isometric to concentric to eccentric activities