IRAT. #4

Spinal Cord Injury (SCI)

An injury to the spinal cord or spinal nerve roots causing temporary or permanent changes in motor, sensory, and/or autonomic function, classified by neurological level and ASIA Impairment Scale (AIS) grade.

Tetraplegia vs. Paraplegia

• Tetraplegia: Cervical SCI affecting all four extremities and trunk, with varying degrees of preserved upper-extremity function.

• Paraplegia: Thoracic, lumbar, or sacral SCI affecting lower extremities and trunk depending on the level, with upper-extremity function spared.

Neurological Level Determination in SCI

Determined via the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) by assessing light touch, pinprick sensation, and 10 key muscles bilaterally ($0\text{--}5$ MMT scale). It is defined as the most caudal segment with intact sensation and muscle strength of at least $3/5$.

Neurological Level vs. Functional Level

• Neurological level: The most caudal segment with intact sensation and antigravity ($\text{grade } \beta \text{ or } \frac{3}{5}$) strength, used for clinical classification and prognosis.
• Functional level: What an individual can accomplish in daily occupations using preserved muscles, adaptive strategies, and equipment.

Complete vs. Incomplete SCI

• Complete SCI (AIS A): Total absence of sensory and motor function in the lowest sacral segments (S4–S5).
• Incomplete SCI (AIS B–D): Partial preservation of sensory and/or motor function in the lowest sacral segments (sacral sparing).

ASIA Impairment Scale (AIS) Grades (A through E)

• AIS A: Complete; no sensory or motor function preserved in S4–S5.
• AIS B: Sensory incomplete; sensory but not motor function preserved below the neurological level and includes S4–S5.
• AIS C: Motor incomplete; motor function preserved below the neurological level, and more than half of key muscle functions have a muscle grade $< 3/5$.
• AIS D: Motor incomplete; motor function preserved below the neurological level, and at least half of key muscle functions have a muscle grade $\ge 3/5$.
• AIS E: Normal; motor and sensory functions are intact.

ISNCSCI Classification Sequence

1. Determine sensory levels (right and left).
2. Determine motor levels (right and left).
3. Determine the single neurological level of injury (NLI).
4. Determine complete vs. incomplete status (sacral sparing at S4–S5).
5. Assign the ASIA Impairment Scale (AIS) grade.

Zone of Partial Preservation (ZPP)

Dermatomes and myotomes caudal to the neurological level that remain partially innervated in clients with complete injuries (AIS A) without sacral sparing.

Root Escape

Preservation or recovery of nerve root innervation at or immediately below the level of spinal injury, yielding functional motor output that enhances ADL performance.

Key Predictors of Neurological Recovery Post-SCI

Completeness of the lesion (complete vs. incomplete) and the standardized ISNCSCI exam conducted $72\,\text{hours}$ to $1\,\text{week}$ post-injury. Most recovery occurs in the first year, but can continue for $3\text{--}4\,\text{years}$.

Central Cord Syndrome

The most common incomplete SCI syndrome, often caused by cervical hyperextension trauma in older adults with cervical stenosis; produces greater motor weakness in upper extremities than in lower extremities, with variable sensory loss and bladder involvement.

Central Cord Syndrome: Prognosis

Generally favorable for ambulation but heavily age-dependent, with walking recovery reported around $97\%$ for individuals under 50 versus $41\%$ for individuals over 50.

Brown-Séquard Syndrome

A hemisection injury of the spinal cord (frequently from penetrating trauma) causing ipsilateral motor paralysis and loss of proprioception/vibration, paired with contralateral loss of pain, temperature, and light touch sensation below the lesion.

Brown-Séquard Syndrome: Functional Prognosis

Highest rate of functional recovery among incomplete cord syndromes, with approximately $75\text{--}90\%$ of individuals regaining independent ambulation by discharge.

Anterior Cord Syndrome

An incomplete cord injury caused by flexion trauma or anterior spinal artery ischemia, resulting in bilateral motor paralysis and loss of pain and temperature sensation below the lesion, while dorsal column proprioception and light touch remain intact.

Anterior Cord Syndrome: Prognosis

Poor motor and functional recovery, with only about a $10\text{--}20\%$ chance of recovering functional motor control.

Conus Medullaris Syndrome

Injury to the sacral cord and lumbar nerve roots within the spinal canal, characteristically causing symmetrical areflexic bladder and bowel dysfunction, saddle anesthesia, and variable lower-extremity paresis.

Cauda Equina Syndrome

Injury affecting the lumbosacral peripheral nerve roots below L2, resulting in flaccid paralysis, asymmetric lower-extremity deficits, saddle anesthesia, and areflexic bowel and bladder.

Regenerative Advantage of Cauda Equina over Spinal Cord Injury

The cauda equina consists of lower motor neurons (peripheral nerves) capable of axonal regeneration at approximately $1\text{--}2\,\text{mm/day}$, whereas central spinal cord tracts lack substantial regenerative capacity.

Clinical OT Approach to Partially Preserved Muscle Activity

Assess its functional utility in daily tasks, protect it from overuse or fatigue, incorporate it into adaptive task execution, and track strength over time rather than prematurely assuming full neurological recovery.

Autonomic Dysreflexia (AD)

A life-threatening, uninhibited autonomic reflex triggered by noxious stimuli below the lesion, occurring predominantly in individuals with SCI at or above T6 and causing sudden paroxysmal hypertension.

Autonomic Dysreflexia: Signs and Symptoms

• Systolic BP elevation $20\text{--}40\,\text{mmHg}$ above baseline
• Pounding headache and anxiety
• Sweating, facial flushing, and piloerection above the lesion level
• Nasal congestion
• Reflex bradycardia

Common Triggers of Autonomic Dysreflexia

Bladder distention or blocked catheter (most common), bowel impaction, pressure ulcers, ingrown toenails, restrictive clothing, deep vein thrombosis, or occult fractures below the lesion.

Autonomic Dysreflexia Emergency Management Sequence

1. Immediately sit the client upright (promotes orthostatic pooling to lower BP).
2. Loosen all constricting clothing, abdominal binders, and compression stockings.
3. Check the urinary system (catheter kinks, drainage bag).
4. Check the bowel and skin for noxious triggers.
5. Monitor blood pressure frequently.
6. Summon emergency medical care.

Orthostatic Hypotension in SCI

A reduction in systolic BP of at least $20\,\text{mmHg}$ upon moving to an upright posture, resulting from impaired sympathetic vasoconstrictor reflex and venous pooling in the abdomen and lower extremities.

Orthostatic Hypotension: Signs and OT Management

• Signs: Dizziness, lightheadedness, nausea, pallor, and syncope.
• Management: Recline or tilt the wheelchair backward, elevate lower extremities, utilize abdominal binders and compression stockings, and progress upright positioning incrementally.

Distinguishing Autonomic Dysreflexia from Orthostatic Hypotension

• Autonomic Dysreflexia: Acute hypertension, pounding headache, diaphoresis; treated by sitting upright.
• Orthostatic Hypotension: Acute hypotension, lightheadedness, syncope; treated by reclining backward and elevating legs.

Reflex vs. Areflexic Neurogenic Bowel and Bladder

• Reflex (Spastic/UMN): Occurs in injuries above T12; sacral reflex arcs remain intact, resulting in hyperreflexic emptying and sphincter dyssynergia.
• Areflexic (Flaccid/LMN): Occurs in injuries at or below T12–L1; sacral reflex arcs are disrupted, causing retention, overflow incontinence, and lack of voluntary sphincter control.

Respiratory Function Impairments by SCI Level

• C1–C3: Denervated diaphragm; requires mechanical ventilation.
• C4: Partially innervated diaphragm; may require ventilatory support.
• C4–T6: Loss of intercostal innervation; reduced vital capacity and weak cough.
• T6–T12: Intact intercostals but weak abdominal muscles; impaired forced expiration and cough.

OT Interventions for Reduced Vital Capacity Post-SCI

Quad-assisted coughing techniques, deep breathing and diaphragmatic exercises, strengthening preserved accessory respiratory musculature, pacing/energy conservation, and coordinating with respiratory care.

Spasticity Post-SCI: Course and Presentation

Velocity-dependent hypertonia caused by loss of descending upper motor neuron inhibition; typically emerges over several weeks, increases over approximately $6\,\text{months}$, and plateaus at roughly $1\,\text{year}$ post-injury.

Significance of a Sudden Increase in Spasticity

Acts as an indicator of a new or occult noxious stimulus below the lesion level, such as a urinary tract infection, occult fracture, bowel impaction, or incipient pressure injury.

Heterotopic Ossification (HO) in SCI

Ectopic lamellar bone formation in soft tissues surrounding major joints (most commonly hips and knees) $1\text{--}6\,\text{months}$ post-injury; presents with localized erythema, warmth, swelling, pain, and restricted joint ROM.

Three Major Post-SCI Pain Categories

• Musculoskeletal: Mechanical joint, bone, or muscle pain worsened by physical movement.
• Neuropathic: Burning, stabbing, or electric dysesthesias from damaged central pathways or nerve roots.
• Visceral: Poorly localized dull, aching, or cramping pain originating from internal pelvic/abdominal organs.

Shoulder Protection and Preservation in SCI

Crucial because repetitive wheelchair propulsion, depression transfers, and weight shifts place excessive demands on the shoulder complex. Interventions focus on transfer mechanics, periscapular strengthening, ergonomic propulsion, and equipment optimization.

C1–C3 SCI: Functional Profile and Technology

Dependent for physical ADLs and mechanical ventilation; uses mouth sticks, environmental control units (ECUs), and power wheelchairs operated via sip-and-puff, chin, or head-array controls to direct care and achieve independent mobility.

C4 SCI: Key Muscles and Functional Abilities

• Key Muscles: Diaphragm, upper trapezius, cervical paraspinals.
• Abilities: Head and neck control, shoulder elevation/shrug; independent in power mobility using specialty controls and caregiver direction, but physically dependent for personal ADLs.

Assistive Devices for High Tetraplegia (C1–C4)

Power tilt-in-space wheelchairs, sip-and-puff interfaces, head or chin controls, mouth sticks, hands-free hydration, robotic feeding systems, and voice-activated environmental control units.

C5 SCI: Key Muscles

Deltoid, biceps brachii, brachialis, brachioradialis, rhomboids, and clavicular/serratus anterior portions.

C5 SCI: Expected ADL Abilities

Active shoulder motion and elbow flexion allow independent feeding and facial grooming with setup and adaptive gear; bathing, lower body dressing, transfers, and bowel/bladder management require moderate to maximal assistance.

Adaptive Equipment for C5 Tetraplegia

Universal cuff with wrist support, mobile arm supports (MAS), plate guard, angled utensils, long drinking straw, and power wheelchair with a standard hand joystick.

C6 SCI: Key Muscles Preserved

Extensor carpi radialis longus and brevis (wrist extension), clavicular pectoralis, supinator, serratus anterior, and latissimus dorsi.

Functional Milestone Significance of C6 SCI

Preservation of active radial wrist extension allows functional tenodesis grasp and release, enabling object manipulation and greater independence without active finger musculature.

C6 SCI: Typical ADL Independence Level

Independent or setup assist for feeding, grooming, and upper-body dressing; assisted for lower-body dressing, bathing, and transfers; capable of manual wheelchair propulsion indoors over level surfaces.

Key Muscle Distinguishing C7 from C6 SCI

Triceps brachii (elbow extension), providing the ability to perform overhead reach, independent depression push-up transfers, and vertical weight relief.

C7–T1 SCI: Functional Milestones

Independence in feeding, grooming, upper and lower dressing, depression transfers, and manual wheelchair propulsion; C8–T1 adds hand intrinsic and extrinsic finger flexor function for standard hand grasp.

T2–T12 SCI: Expected Functional Capabilities

Intact upper-extremity motor function and manual dexterity, full independence in personal ADLs and sliding-board or depression transfers, manual wheelchair propulsion, with trunk balance improving from upper to lower thoracic levels.

L1–S5 SCI: Functional Capabilities

Full independence in upper-extremity self-care and mobility; potential for functional household or community ambulation with orthoses (KAFOs, AFOs) and crutches/canes depending on preserved lower extremity myotomes.

Tenodesis Grasp Mechanism

A passive mechanical grasp produced when active wrist extension tensions the long finger flexor tendons, drawing the fingers into flexion; wrist flexion releases the passive tension to open the fingers.

Clinical Rational for Preserving Finger Flexor Tightness in C6 SCI

A degree of passive flexor tendon tightness is required to achieve functional pinch/grasp force upon wrist extension; overstretching these flexors renders tenodesis functionally ineffective.

Range of Motion (ROM) Protocol for Tenodesis Grasp

Perform finger flexion with the wrist extended; perform finger extension only with the wrist flexed. Never allow simultaneous passive wrist and finger extension.

Splinting for C6 SCI with Wrist Extension Strength < 3+/5

A resting splint that maintains the wrist in neutral, the thumb in opposition, and the MCP and IP joints in slight flexion to support weak wrist extensors and protect finger flexor tightness.

Splinting for C6 SCI with Wrist Extension Strength ≥ 3+/5

A short opponens splint or wrist-driven tenodesis orthosis to support thumb web-space stability and enhance functional pinch.

Contractures of Primary Concern at C5 SCI

Elbow flexion and forearm supination contractures resulting from unopposed biceps pull; managed with pronation positioning and elbow extension resting splints.

Locked-Elbow Technique for C6 Tetraplegia

A method to stabilize the upper extremity during transfers without triceps by using shoulder external rotation, adduction, elbow hyperextension, and wrist extension to lock the joint mechanically.

Recommended Seated Pressure Relief Schedule

Perform pressure relief every $30\text{--}60\,\text{minutes}$ for at least $1\text{--}2\,\text{minutes}$ until skin tolerance and safe schedules are firmly established.

Pressure Relief Techniques by SCI Level

• C1–C4: Power tilt-in-space ($\ge 45\text{--}55^{\circ}$).
• C6 (intact shoulder/elbow flexors): Forward lean over thighs or lateral lean.
• C7 (triceps $\ge 3+/5$): Vertical depression push-up.
• Paraplegia: Depression push-up or forward lean.

Etiology of Pressure Injuries

Localized cellular ischemia and tissue necrosis caused by prolonged unrelieved pressure, or pressure combined with shear forces, over bony prominences; compounded by moisture, reduced perfusion, and sensory loss.

Stage 1 Pressure Injury

Intact skin with localized, non-blanchable erythema over a bony prominence; may be accompanied by localized changes in skin temperature, firmness, or tenderness.

Stage 1 Pressure Injury Identification in Dark Skin Tones

Erythema may not blanch or be clearly visible; look for skin that appears darker, purplish, or bluish compared to surrounding areas, alongside local induration, warmth, coolness, or boggy texture.

Stage 2 Pressure Injury

Partial-thickness loss of skin with exposed dermis; features a viable, moist, pink or red wound bed without slough or eschar; can also present as an intact or ruptured serum-filled blister.

Exclusionary Findings for Stage 2 Pressure Injuries

Visible adipose tissue, slough, eschar, granulation tissue, or exposed deeper structures; presence of bruising points to deep tissue pressure injury.

Stage 3 Pressure Injury

Full-thickness skin loss where subcutaneous fat is visible; granulation tissue, epibole, slough, eschar, undermining, and tunneling may be present, but fascia, muscle, tendon, and bone remain unexposed.

Stage 4 Pressure Injury

Full-thickness skin and tissue loss with directly visible or palpable fascia, muscle, tendon, ligament, cartilage, or bone; undermining, tunneling, and rolled wound edges (epibole) frequently occur.

Unstageable Pressure Injury

Full-thickness tissue loss in which the actual extent of tissue damage cannot be confirmed because the wound bed is obscured by slough or eschar.

Management Precaution for Stable Heel Eschar

Dry, adherent, intact heel eschar without erythema or fluctuance functions as a protective biological cover and must not be debrided, softened, or unroofed.

Deep Tissue Pressure Injury (DTPI)

Intact or non-intact skin exhibiting persistent, non-blanchable deep red, maroon, or purple discoloration, or epidermal separation revealing a dark wound bed or blood-filled blister from bone-tissue interface damage.

Deep Tissue Pressure Injury Identification in Dark Skin Tones

Inspect and palpate for localized purple or maroon hues, dark blood-filled blisters, focal changes in temperature (warmer or cooler), local induration, or boggy/mushy tissue consistency.

Medical Device-Related vs. Mucosal Pressure Injuries

• Device-Related: Arises from diagnostic or therapeutic devices resting on skin; mirrors the device's shape and is staged using the standard system.
• Mucosal: Arises on moist mucosal linings from devices (e.g., endotracheal or Foley tubes); cannot be staged using standard skin injury staging.

Differentiating Stage 3, Stage 4, and Unstageable Pressure Injuries

• Stage 3: Full-thickness loss extending into adipose only; deeper tissues unexposed.
• Stage 4: Full-thickness loss directly exposing or palpating fascia, muscle, tendon, or bone.
• Unstageable: Depth cannot be determined due to overlying slough or eschar.

Clinical Indicators for Skin Assessment in Darkly Pigmented Tissue

Localized changes in color from adjacent skin, localized edema, induration, bogginess, focal warmth or coolness, and client-reported altered sensation or pain.

Occupational Therapy Role in Pressure Injury Prevention

Instruction in timed pressure-relief strategies, shear-free transfer mechanics, mirror-assisted daily skin checks, wheelchair seating/cushion prescription, and monitoring splint/brace fit.

Manual Muscle Testing (MMT)

A standardized clinical evaluation method used to measure the tension-generating capacity and voluntary force of an isolated muscle or muscle group during a maximum voluntary contraction.

Muscular Strength vs. Muscular Endurance

• Strength: The maximum force or tension produced by a muscle or muscle group during a single voluntary effort.
• Endurance: The capacity of a muscle to perform repeated contractions or sustain static tension over time without fatigue.

Clinical Purpose of MMT in SCI

To determine neurological and motor levels of injury, establish functional baselines, identify muscle imbalances, guide orthotic prescriptions, and track motor recovery over time.

Standard Manual Muscle Testing (MMT) Sequence

1. Determine available PROM.
2. Proceed proximal to distal.
3. Position client against gravity.
4. Stabilize proximal attachment.
5. Active movement through available range.
6. Apply distal resistance if full range against gravity is met.
7. Test in gravity-eliminated plane if unable to complete range against gravity.
8. Palpate prime mover if joint motion is absent.

Stabilization and Resistance Placement in MMT

Stabilize immediately proximal to the joint being moved; apply manual resistance at the distal end of the moving bone segment, typically at the end of the available range of motion.

MMT Grade 5 (Normal)

Completes full available ROM against gravity and holds the test position against maximal resistance.

MMT Grade 4 (Good)

Completes full available ROM against gravity and holds the test position against moderate resistance.

MMT Grade 3+ (Fair+)

Completes full available ROM against gravity and holds the test position against minimal resistance.

MMT Grade 3 (Fair)

Completes full available ROM against gravity but yields immediately to additional manual resistance.

MMT Grade 3– (Fair–)

Completes greater than half but less than full available ROM against gravity.

MMT Grade 2+ (Poor+)

Completes full available ROM in a gravity-eliminated position and tolerates minimal resistance before yielding.

MMT Grade 2 (Poor)

Completes full available ROM in a gravity-eliminated position without tolerating additional resistance.

MMT Grade 2– (Poor–)

Completes less than full available ROM in a gravity-eliminated position.

MMT Grade 1 (Trace)

No joint motion produced, but palpable or observable contractile flicker is detected in the muscle belly or tendon.

MMT Grade 0 (Zero)

Complete absence of muscle contraction, with no joint movement and no palpable or visible muscle flicker.

MMT Grade: Full PROM, Incomplete AROM Against Gravity, Full AROM Gravity-Eliminated

Grade 2 (Poor), because the client cannot achieve full range against gravity but achieves full range when gravity is eliminated.

Four Main Types of Muscle Strength Assessment

1. Gross strength screening
2. Individual muscle MMT
3. Muscle group MMT
4. Functional strength testing

Clinical Indications for Individual Muscle MMT

Evaluating peripheral nerve injuries or determining specific spinal cord lesion levels, where isolating specific myotomes and individual muscle innervations is required.

Indications for Functional Strength Testing over MMT

When resisted testing is contraindicated (e.g., healing bone fractures, sternotomy precautions), but the therapist needs to assess functional capacity during daily activities.

Precautions and Contraindications for Resisted MMT

Unhealed fractures, joint dislocation, heterotopic ossification, severe osteoporosis, acute inflammation, recent tendon repair, severe cardiovascular disease, hernia, and acute fatigue.

Why Isolated MMT is Inappropriate for Patterned/Synergistic Movement

Upper motor neuron lesions often produce obligatory mass movement synergies and spasticity, making isolated voluntary muscle activation and standardized grading invalid.

Factors Influencing MMT Reliability

Client effort, pain, comprehension of instructions, positioning accuracy, therapist experience, placement of manual resistance, and ambient clinic distractions.

Best Practices for Documenting MMT Results

List muscles in a proximal-to-distal progression, record numerical or standardized letter grades, note significant asymmetries, and explain how specific deficits restrict occupational performance.

Classification of Weakness Severity

• Slight Weakness: Good range ($\text{Grade } 4$)
• Moderate Weakness: Fair to Fair+ range (\text{Grade } 3 \text{ to } 3+\)\n- **Severe Weakness**: Below Fair range (\text{Grade } < 3$$)

OT Role in Independence for High Cervical Tetraplegia (C1–C4)

Fostering client autonomy through training in directing caregivers, implementing assistive environmental control technology, managing schedules, and facilitating decision-making.

Minimum Muscle Strength for Upper-Body Dressing Training

Fair to Good ($3/5\text{--}4/5$) strength in deltoids, trapezius, rhomboids, biceps, supinators, and radial wrist extensors.

Minimum Upper-Extremity ROM for Upper-Body Dressing Training

• Shoulder flexion/abduction: $0\text{--}90^{\circ}$
• Shoulder internal rotation: $0\text{--}80^{\circ}$
• Shoulder external rotation: $0\text{--}30^{\circ}$
• Elbow flexion: $15\text{--}140^{\circ}$

Prerequisites for Lower-Body Dressing in Tetraplegia

Fair to Good strength in pectoralis and serratus anterior; knee flexion to $120^{\circ}$, hip flexion to $110^{\circ}$, hip external rotation to $80^{\circ}$; minimal assist bed transfers; rolling and side-lying balance; and vital capacity $> 50\%$.