Attention S&B lesson4

1. S&B 4
Dr Amala Musti
Consultant psychiatrist
Columbus hospital, Begumpet

2. • Pt ability to sustain attention over time must be established before the more complex functions such as memory,
language and abstract thinking are evaluated.
• The inattentive and distractable pt cannot efficiently assimilate the information presented during testing.
• Eg no value to ask pt to remember a story who is distracted by the nurse passing in the hall

3. Attention Alertness
• Attention is ability to attend to a specific / single
stimulus without being distracted
Whereas alertness differs from attention, respond to
any stimulus
• Can screen out irrelevant stimuli Attracted to any novel stimulus

4. • Vigilance (concentration) is the ability to sustain attention over an extended
period.
• Inattention can be in two contexts
Inattention of cognitive task
Inattention of sensory task

5. Evaluation
• Observation
• Pt’s general attentiveness obtained by observing pt’s behaviour – distractability or
difficulty in attending examiner.
• History
• Enquiry from pt and attenders about accomplishing tasks

6. Digit repetition
• Barring aphasia pt
• Test items
• 3-7 9-2
7-4-9 1-7-4
8-5-2-7 5-2-9-7
2-9-6-8-3 6-3-8-5-1
5-7-2-9-4-6 2-9-4-7-3-8
8-1-5-9-3-6-2 4-1-9-2-7-5-1
3-9-8-2-5-1-4-7 8-5-3-9-1-6-2-7
7-2-8-5-4-6-7-3-9 2-1-9-7-3-5-8-4-6
Pt of average intelligence can accurately repeat 5-7 digits without difficulty

7. • VIGILANCE
• “A” Random letter test
• Examiner specifies a target letter eg A. Later pt needs to indicate whenever the
target letter is come across a series of random letters.
• TEST ITEMS
LT P E A O A I CT D A L A A
A N I A B F S A M R Z E O A D
P A K L A U C JT O E A B A A
ZY F M U S A H EV A A R AT

8. • Common organic errors :
• 1) failure to indicate target
• 2) indicating non target letter
• 3) failure to stop tapping

9. • Serial substraction test : has limited validity and reliability
• Studies in performance of this test suggest that errors on this test may reflect
premorbid intellectual capability, education, calculating ability or socioeconomic
status rather indicating pathologic process
• Excellent performance --- adequate attention or mental control
• Failure indicate no of problems inattention being one.

10. INATTENTION
• Unilateral inattention should be tested during routine sensory examination by
double simultaneous stimulation.
• If one side is inferior than the other doesnot reflect inattention.
• Extinction -- pt suppresses stimuli from one side of the body
• Extinction occur in all modalities
• In case of extinction, inattention elicited by increasing the magnitude of stimulus
• When double stimulation involves one proximal and one distal
• Distal tends to be extinguished esp face and hand

11. • Normal adults <65 years often extinguish in first trial, recognize after several
attempts
• Organic brain syndromes rarely recognize hand stimulus as many as 10trials
• Some normal adults >65 years tend to extinguish
• Test must be interpreted with caution

12. ANATOMY AND CLINICAL
IMPLICATIONS
• Attention results from balance among ascending (reticulocortical) activation,
ascending inhibition, and cortical (corticoreticular)modulation.
• Attention represents a complex interaction of limbic, neocortical and ascending
activating functions.
• Lesion in mid brain activating system produces clinically rare profound unilateral
inattention.

13. • Enchephalitis epidemic of 1918 causing voneconomo’s disease, were left with
lesion in ascending inhibitory portion of pons and medulla reticular substance.
• Causing distractibility and hyperactivity

14. • Right (non dominant) hemisphere leisons have stronger effect on attention than
do left sided lesion.
• Denia,l unilateral neglect and extinction on double simultaneous stimulation are
more frequent with right hemisphere lesion
• Contralateral inattention – parietal lesion