Rutgers PM&R conference Study guide

PM&R and Neuro Rehabilitation Study Guide

Movement Disorders: Dystonia vs Spasticity

  • Dystonia

    • Definition: A movement disorder characterized by involuntary sustained muscle contractions.

    • Symptoms: Causes twisting movements or abnormal postures.

    • Association: Commonly associated with basal ganglia dysfunction.

  • Spasticity

    • Definition: A velocity-dependent increase in muscle tone.

    • Mechanism: Caused by upper motor neuron lesions.

    • Characteristics: The faster a limb is moved passively, the greater the resistance encountered.

    • Common Conditions: Occurs after stroke, spinal cord injury, traumatic brain injury, or multiple sclerosis.

Pharmacologic Treatment of Spasticity

  • Common medications used include:

    • Baclofen

    • Mechanism: GABA-B receptor agonist acting primarily at the spinal cord.

    • Classification: First-line therapy for spasticity treatment.

    • Tizanidine

    • Mechanism: Alpha-2 adrenergic agonist that decreases excitatory motor neuron activity.

    • Benzodiazepines

    • Mechanism: GABA-A receptor agonists that increase CNS inhibition.

    • Dantrolene

    • Mechanism: Acts directly on skeletal muscle by blocking calcium release from the sarcoplasmic reticulum.

Serial Casting

  • Technique: Used to gradually improve joint range of motion.

  • Implementation:

    • Repeated casts hold a limb in a stretched position.

    • Casts are replaced every few days with progressively increased stretch.

  • Application: Commonly used for spasticity or contractures, particularly in patients with cerebral palsy or after stroke.

Chemodenervation and Botulinum Toxin

  • Chemodenervation Definition: Involves injecting botulinum toxin into a muscle affected by spasticity.

  • Mechanism of Action:

    • Botulinum toxin cleaves SNARE proteins, preventing acetylcholine release at the neuromuscular junction.

    • Results: This produces temporary muscle paralysis.

  • Rule of 3s:

    • Begins working in about 3 days.

    • Peak effect around 3 weeks.

    • Wears off in about 3 months.

  • Benefit: Allows targeted treatment of focal spasticity, minimizing systemic medication side effects.

Modified Ashworth Scale

  • Purpose: Measures spasticity by grading resistance during passive movement.

  • Grading System:

    • 0 – No increase in muscle tone

    • 1 – Slight increase with catch and release

    • 1+ – Catch with minimal resistance through less than half of the range of motion (ROM)

    • 2 – Marked increase in tone, but limb moves easily

    • 3 – Considerable increase in tone

    • 4 – Limb rigid in flexion or extension

Injection Guidance Techniques

  • Methods utilized for accurate botulinum toxin injections include:

    • Landmark based techniques

    • EMG-guided injections

    • Purpose: Detects electrical activity in the muscle to ensure correct injection placement.

    • Electrical stimulation

    • Ultrasound guidance

Intrathecal Baclofen Therapy

  • Definition: Delivers baclofen directly into cerebrospinal fluid via an implanted pump.

  • Advantages:

    • Direct action at the spinal cord level.

    • Reduced systemic side effects compared to oral medication.

    • Adjustable dosing.

  • Risks:

    • Possible pump malfunction.

    • Life-threatening baclofen withdrawal syndrome.

Cryoneurolysis

  • Definition: Technique that freezes peripheral nerves using temperatures between −20°C and −100°C.

  • Effect: Produces temporary axonal injury while preserving the nerve's framework, allowing for regeneration.

  • Regeneration Rate: Peripheral nerve regeneration occurs at approximately 1–2 mm per day.

  • Duration of Effects: Effects may last from several months up to a year.

Shoulder Pain Differential Diagnosis

  • Common causes of shoulder pain include:

    • Rotator cuff tear

    • Biceps tendonitis

    • Calcific tendonitis

    • SLAP tear

    • Adhesive capsulitis (frozen shoulder)

    • AC joint pathology

    • Shoulder osteoarthritis

Adhesive Capsulitis (Frozen Shoulder)

  • Definition: Results from capsular fibrosis of the glenohumeral joint.

  • Most Restricted Movement: External rotation.

  • Classic Pattern of Motion Loss:

    • External rotation → Abduction → Internal rotation

  • Range of Motion: Both active and passive range of motion are restricted.

Ultrasound Signs in Shoulder Imaging

  • Geyser sign: Fluid from the glenohumeral joint passes through a rotator cuff tear into the AC joint.

  • Rabbit sign: Ultrasound appearance of the long head of the biceps tendon in the bicipital groove.

Glenohumeral Joint Injection

  • Technique: Ultrasound-guided injection of corticosteroid and anesthetic directly into the shoulder joint.

  • Indications: Used for frozen shoulder, osteoarthritis, inflammatory arthritis, and diagnostic evaluation of shoulder pain.

Glasgow Coma Scale (GCS)

  • Purpose: Evaluates consciousness using three components:

    • Eye opening (1–4)

    • Verbal response (1–5)

    • Motor response (1–6)

  • Scoring:

    • Total score ranges from 3 to 15.

    • Scores of ≤8 indicate severe brain injury and often necessitate airway protection.

Diffuse Axonal Injury

  • Definition: Occurs when rapid acceleration or deceleration causes shearing of axons throughout the brain.

  • Common Sites of Injury:

    • Gray-white matter junction

    • Corpus callosum

    • Brainstem

  • Imaging Studies: MRI is more sensitive than CT for detecting diffuse axonal injury (DAI).

Heart Transplant Physiology

  • Condition: Transplanted hearts are denervated and lose sympathetic and parasympathetic input.

  • Heart Rate Response: Heart rate can still increase due to circulating catecholamines acting on beta-1 receptors.

Heterotopic Ossification

  • Definition: Abnormal bone formation in soft tissues around joints.

  • Common Occurrence: Typically occurs after traumatic brain injury or spinal cord injury, often affecting the hip.

Brainstem and Consciousness in TBI

  • Function: The brainstem contains the reticular activating system responsible for maintaining consciousness.

  • Consequences of Damage: Damage in traumatic brain injury can impair this system and potentially lead to coma.

Amputation Contractures

  • Common Contracture: In transfemoral (above-knee) amputees, the most frequent contracture is hip flexion contracture.

  • Recommendation: Prone positioning is suggested to stretch hip flexors and prevent additional contracture formation.