In a comatose patient, which components of the NIH Stroke Scale can be scored and which cannot?

NIHSS Scoring in Comatose Patients

In a comatose patient, you can score most NIHSS components using reflex responses, pain stimulation, and observation, but you cannot reliably assess orientation (1b), commands (1c), limb ataxia (7), language (9), dysarthria (10), or extinction/inattention (11).

Components That CAN Be Scored

Level of Consciousness (1a) - Alertness

• Always scorable - This is specifically designed for comatose patients
• Score 3 = "reflex responses or unarousable" 1, 2
• This is the primary item that defines coma in the NIHSS

Best Gaze (2)

• Can be assessed using Doll's eyes maneuver (oculocephalic reflex)
• The scale explicitly states: "Only horizontal eye movements are checked by voluntary movement or reflective movement (Doll's eyes, not by calorics)" 1
• Score based on whether forced eye deviation can be overcome by Doll's eyes

Visual Fields (3)

• Can be tested using visual threat if necessary
• The instructions specifically state: "Test using confrontation (or visual threat if necessary)" 1
• Observe for blink response or flinching to visual threat in each visual field

Facial Palsy (4)

• Explicitly scorable in stuporous/comatose patients
• The scale states: "If stuporous, check symmetry of grimace to pain" 1
• Apply painful stimulus and observe facial symmetry during grimacing

Motor Arm (5) and Motor Leg (6)

• Can be scored based on response to painful stimulation
• Score 3 = "No antigravity effort, but even minimal movement counts"
• Score 4 = "No movement at all"
• Apply noxious stimulus and observe for any limb movement 1

Sensory (8)

• Can be assessed in stuporous patients
• The instructions state: "Use safety pin. Check grimace or withdrawal if stuporous" 1
• Score 2 = "Total loss, patient unaware of touch, coma, bilateral loss"
• Observe for grimacing or withdrawal to pinprick

Components That CANNOT Be Reliably Scored

Orientation (1b)

• Cannot be assessed - requires verbal responses
• Asks patient age and month; answers must be exact
• In coma, automatically score 2 = "Neither correct" 1, 2

Response to Commands (1c)

• Cannot be assessed - requires voluntary cooperation
• Asks patient to open/close eyes and grip/release hand
• In coma, automatically score 2 = "Neither correct" 1, 2

Limb Ataxia (7)

• Cannot be assessed - requires voluntary, coordinated movement
• Requires finger-to-nose and heel-to-shin testing
• The scale notes: "0=No ataxia (or aphasic, hemiplegic)" - acknowledging it cannot be tested in certain states
• Score as "0" or mark as "X=Unable to assess" 1

Best Language (9)

• Cannot be assessed - requires verbal/comprehension abilities
• Requires describing pictures, naming objects, reading sentences
• Score 3 = "Mute, global aphasia, coma" 1

Dysarthria (10)

• Cannot be assessed - requires speech production
• Requires reading list of words
• Mark as "X=Intubation or mechanical barrier" or score 2 if mute 1

Extinction/Inattention (11)

• Cannot be assessed - requires conscious awareness and cooperation
• Requires simultaneous bilateral stimulation and patient recognition
• Cannot be reliably tested in comatose patients 1

Clinical Pitfalls and Practical Considerations

Common scoring errors in comatose patients:

• Failing to use Doll's eyes for gaze assessment - this is explicitly allowed and necessary in unresponsive patients
• Not applying adequate painful stimulation - you must use sufficient noxious stimulus to elicit grimace for facial palsy and motor responses
• Incorrectly scoring ataxia - this should be marked as untestable (X) or scored 0, not assigned points based on speculation

Important caveats:

• The presence of sedation, neuromuscular blockade, or intubation further complicates scoring 3
• Document these confounders clearly as they affect interpretation
• In comatose patients, the scorable items will typically yield high NIHSS scores (indicating severe stroke), which is prognostically important for treatment decisions and hemorrhage risk assessment 2

Practical approach: Score what you can observe directly (consciousness level, reflexive eye movements, grimace symmetry, motor responses to pain, sensory withdrawal), and appropriately mark items requiring cooperation as maximum deficit or untestable.