How do you assess extinction and inattention in a patient?

Assessment of Extinction and Inattention in Neurological Examination

To properly assess extinction and inattention, use simultaneous bilateral stimulation across multiple sensory modalities while ensuring the patient can detect stimuli presented individually to either side.

Standard Assessment Method Based on NIHSS

The National Institutes of Health Stroke Scale (NIHSS) provides a standardized approach to assess extinction and inattention (item 11) 1:

Visual Assessment

1. Introduce yourself and explain the test
2. Position yourself directly in front of the patient
3. First test each visual field individually to confirm the patient can detect stimuli on each side
4. Then perform simultaneous bilateral visual stimulation:
   • Hold your index fingers approximately 45 cm from the patient's face
   • Position fingers in both visual fields (left and right upper quadrants)
   • Ask the patient to identify which finger(s) is/are moving or both
   • Repeat in lower quadrants if needed

Tactile Assessment

1. First confirm the patient can feel touch on each side individually
2. Then perform simultaneous bilateral tactile stimulation:
   • Touch the patient on both hands simultaneously
   • Ask which side(s) they felt the touch or if they felt both

Auditory Assessment (if needed)

1. First test each ear individually
2. Then perform simultaneous bilateral auditory stimulation
3. Ask which sound(s) they heard

Scoring Based on NIHSS

The NIHSS grades extinction/inattention as follows 1:

• 0 = No abnormality detected
• 1 = Visual, tactile, auditory, spatial, or personal inattention OR extinction to bilateral simultaneous stimulation in one sensory modality
• 2 = Profound hemi-inattention or extinction to more than one modality

Additional Assessment Techniques

Double Simultaneous Stimulation (DSS)

This is the core technique for detecting extinction:

• First test each side individually to establish baseline sensory function
• Then stimulate both sides simultaneously
• A positive extinction response occurs when the patient reports only the ipsilesional stimulus despite being able to detect each stimulus when presented alone

Specialized Tests for Visual Neglect/Inattention

1. Line Bisection Test:

   • Have the patient mark the midpoint of horizontal lines
   • Deviation toward the ipsilesional side suggests contralesional neglect

2. Cancellation Tasks:

   • Present arrays of targets (letters, symbols, etc.)
   • Ask patient to cross out all targets
   • Failure to cancel targets on contralesional side indicates neglect

3. Figure Copying:

   • Have patient copy a simple drawing
   • Omission of elements on contralesional side indicates neglect

4. Clock Drawing Test:

   • Ask patient to draw a clock face with all numbers
   • Crowding of numbers on ipsilesional side or omission on contralesional side suggests neglect

Important Clinical Considerations

1. Distinguish from Visual Field Defects:

   • Visual field defects can be confused with neglect/extinction
   • The NIHSS visual field test (item 3) should be performed first to establish baseline visual function 2
   • Accuracy of extinction detection decreases to 61.1% in patients with visual field deficits 2

2. Task Demands Matter:

   • Subtle extinction may only appear under increased attentional load 3
   • Standard paper-and-pencil tests may miss extinction that becomes apparent during more demanding tasks
   • Consider using tasks with varying levels of difficulty

3. Behavioral Assessment:

   • The Rivermead Behavioral Inattention Test assesses neglect in activities of daily living 4
   • Observing functional activities (eating, dressing, mobility) can reveal neglect not detected on formal testing

4. Non-Spatial Factors:

   • Extinction can be modulated by:
     • Visual grouping (Gestalt properties)
     • Higher-level factors (lexical identity, action relations between objects)
     • Working memory load 5

Clinical Pitfalls to Avoid

1. Relying solely on NIHSS: The NIHSS extinction/inattention item has only moderate agreement (kappa = 0.404) with specialized neglect tests 2

2. Inadequate baseline testing: Always test each side individually first to confirm the patient can detect stimuli when presented alone

3. Insufficient sensory modalities: Test multiple sensory modalities as extinction may be present in one but not others

4. Missing subtle signs: Patients may compensate during simple clinical tests; more demanding tasks may be needed to reveal subtle deficits

5. Confusing with other deficits: Distinguish extinction from primary sensory deficits, visual field cuts, and language disorders

By systematically assessing extinction and inattention across multiple sensory modalities and using appropriate task demands, clinicians can accurately identify these important neurological deficits that significantly impact functional recovery and rehabilitation outcomes.