Modified Rankin Scale (mRS) in Stroke

The mRS Score - How to Apply It

• Adams and Victor's Principles of Neurology, 12th Ed., Table 33-4
• Fuster and Hurst's The Heart, 15th Ed., p. 817

How to Apply / Assess the mRS

1. Timing

• Can be assessed at admission (to capture pre-stroke baseline) and at discharge or 90 days (to measure outcome).
• The pre-stroke mRS is especially important for treatment eligibility (e.g., thrombectomy requires pre-stroke mRS < 2).
• 90-day mRS is the standard primary endpoint in most stroke clinical trials (e.g., DAWN, DEFUSE-3, MR CLEAN trials).

2. Assessment Method

• mRS can be assessed by physicians, nurses, or trained non-physicians - it requires less training than the NIHSS.
• A structured interview (e.g., the mRS-9Q questionnaire or mRS-SI) significantly improves inter-rater reliability.
• Ask the patient or caregiver about functional independence in daily life (not just neurological deficits), with reference to the patient's pre-stroke baseline activities.

3. Key Questions to Ask

• Can the patient walk independently?
• Can they manage their own personal care (dressing, bathing, toileting)?
• Do they need help with everyday tasks?
• Are they bedridden?
• Is there any change from how they were before the stroke?

4. Defining "Good Outcome"

• mRS 0-2: Functionally independent - used as "good outcome" in most major trials (MR CLEAN, SWIFT PRIME, ESCAPE).
• mRS 0-3: Also used as "good outcome" in some trials, though mRS 3 (moderate disability) still indicates the patient can walk without assistance.
• A single point change on the mRS represents a clinically meaningful difference.

Where mRS Is Used Clinically in Stroke

1. Patient selection for thrombectomy: AHA/ASA guidelines require pre-stroke mRS 0-1 (or ≤2) for endovascular therapy with a stent retriever.
2. Outcome reporting: Standard endpoint in all major stroke trials (NINDS tPA trial, mechanical thrombectomy trials).
3. Discharge planning and rehabilitation: Guides intensity of PT/OT/speech therapy and level of care required.
4. Thrombolysis eligibility: Post-alteplase 90-day mRS 0-1 was achieved in 53.3% vs 41.8% placebo in major trials.
   • Tintinalli's Emergency Medicine, block14

mRS vs. Other Stroke Scales

How to Apply a Muscle Stimulator (NMES/FES) for Stroke Rehabilitation

• NMES (Neuromuscular Electrical Stimulation) - stimulates peripheral nerves/motor points to contract weakened or paralyzed muscles
• FES (Functional Electrical Stimulation) - a type of NMES timed to a functional movement (e.g., foot lift during walking, finger grasp)
• TENS - primarily for pain relief (post-stroke shoulder pain), not motor recovery

How Electrical Stimulation Helps After Stroke

• Bradley and Daroff's Neurology in Clinical Practice, p. 2785

Step-by-Step: How to Apply NMES for Stroke

Step 1 - Prepare the Skin

• Clean the skin with water or alcohol wipe where electrodes will be placed
• Make sure the skin is dry and free of lotion, oil, or rash
• Check for any broken skin, wounds, or metal implants (pins, staples) - do NOT place electrodes over these areas

Step 2 - Identify the Target Muscle and Motor Point

• The electrodes go directly over the muscle you want to contract
• Find the motor point - the spot on the skin where the nerve enters the muscle belly; this gives the strongest and most efficient contraction with less current
• Place electrodes along the direction of the muscle fibers

Step 3 - Electrode Placement by Body Region

Step 4 - Connect and Set the Device

Step 5 - Active Participation (Very Important)

• NMES for stroke should not be purely passive
• The patient should try to move the muscle themselves at the same time as the electrical stimulation fires
• This combination of volitional effort + electrical stimulation drives neuroplasticity far better than stimulation alone
• This is the basis of EMG-triggered NMES - stimulation fires only when the patient attempts a voluntary contraction

Step 6 - After the Session

• Check the skin under electrodes for redness or irritation
• Rotate electrode placement slightly each session to prevent skin breakdown
• Record progress and adjust intensity as the patient improves

Areas to Avoid

• Eyes or face (unless under specialist supervision)
• Heart or chest (especially with pacemaker/ICD)
• Throat/carotid arteries (can affect heart rate)
• Reproductive organs
• Over metal implants (pins, staples, plates)
• Broken or infected skin
• Tumors or active cancer sites

Contraindications

• Pacemaker or implanted cardiac device
• Deep vein thrombosis (DVT) in the stimulated limb
• Epilepsy (avoid stimulation near the head)
• Pregnancy (avoid abdominal/pelvic areas)
• Impaired sensation without supervision (risk of burns from unrecognized excess stimulation)

Common Clinical Applications in Stroke

1. Upper limb motor recovery - wrist/hand extension for grasping; improves arm function and reduces spasticity
2. Foot drop - tibialis anterior stimulation timed to swing phase of walking (FES)
3. Shoulder subluxation - deltoid/supraspinatus stimulation to prevent downward subluxation in flaccid hemiplegia
4. Dysphagia - suprahyoid NMES combined with effortful swallowing (therapist-administered only)
5. Spasticity management - reciprocal stimulation of antagonist muscles can reduce spastic tone

Key Principle

Important: Always have a physiotherapist or occupational therapist assess the patient first, teach electrode placement, and set appropriate parameters before any home use. Incorrect application - especially near the neck, face, or chest - can be dangerous.