1. M65
Unconscious Sensor y Per ception
in
a Case of Hemine glect
Authors:
Ramachandran S. Vilayanur
Srinivasan V. Avathvadi
Bijoy K. Menon, Nithyanandam V. Allimuthu, Diane R. Rogers
Monday, October 9, 2006 Poster Session II

2. Objective and Background
 To describe dissociation between various
tests of personal neglect and to
demonstrate unconscious sensory
perception.
 Personal neglect is tested by Bisiachs test
or by tests of attention to the left half of
body. Normally these tests are congruent

3. Designs/Methods
Case vignette
Indrani. 50 year old female
 Presents with sudden onset of weakness
of left upper and lower limb
 O/E.
 Conscious, oriented to time, place and person
 Mild left UMN facial paresis
 Left hemiplegia
 All peripheral pulses palpable

4.  CT Brain – P – Shows a (R)
Occipitotemporal infarct

5. Higher mental function evaluation
 MMSE : 28/30
 She was very attentive and quite clear in her
conversation with us, though she would be
complaining of a vague left sided shoulder pain
On lobar testing, she had
 Left visual neglect with (L) hemianopia
 No auditory neglect
 Absent sensory perception in (L) upper limb and (L)
tactile neglect in the lower limb

6. Designs/Methods
Our patient had (L) hemiplegia, (L)
somatosensory loss with (R)
temperooccipital infarct.
Neuropsychological evaluation revealed
the following.

9. On cold caloric tests and its
effect on neglect

10. Video of Neglect

11. Video of caloric test and Nystagmus

12. Video of disappearance of neglect

13. On ‘ Mirror Agnosia’
Mirror Agnosia on the Right

14. After caloric test, Mirror Agnosia
on the Left

15. ‘Mirror Agnosia’ to front

16.  On Anosognosia, Body neglect
(Hemisomatognosia) and
somatoparaphrenia
 Anosognosia – our patient has it
 Body neglect by Bisiach’s test – our patient
does not have it
 Somatoparaphrenia – our patient has it

17. Somatoparaphrenia

18. On the somatophrenic arm and mirrors

19.  On Allesthesia, tactile neglect and
‘blind touch’
 ‘Touch your left arm’ Bisiach’s test of
body neglect.
 Absent proprioception and touch in
the left upper limb
 Patient is still able to touch her left
arm whatever position the examiner
keeps the arm in.

20. Blind Sight Vs Blind Touch

21.  On visual imagery, neglect and caloric
tests
 Visual imagery
 Bisiach’s test
 Our test

22. Results

23. Results
 Our patient had personal neglect on
tests of attention to the left half of her
body with anosognosia grade I and
severe somatophrenia of her left arm.
Intriguingly, when asked to point to her
left eye she grasped her left hand with
her intact right arm and used it to touch
her eye showing tacit knowledge of
paralysis despite anosognosia and
somatophrenia.

24. Results Cont..
 We show unconscious sensory
perception in a patient with sensory
loss, somatophrenia and neglect. This
is a new phenomenon similar to blind
sight.

25. Discussion
 Neglect – Cognitive inability to response to contralesional
stimulus – Robertson and Marshall
 Blindsight – Weiskrant et al., 1974
– Interesting question is: if the parients can ‘see’ the
stimulus enough to point to it, why aren’t they
consciously aware of it?
 Patient with Unilateral neglect
– Unilateral neglect is, in a sense, the opposite side of this
coin.
– A patient with neglect fails to respond and report objects
and stimuli presented in the region opposite to the lesion
site, but has an otherwise intact visual field.

26. Discussion cont..
 By showing unconscious sensory
perception in a patient with sensory loss,
somatophrenia and neglect, we suggest
that this is a new phenomenon similar to
blind sight and raises questions about
unconscious sensory perception.

27. Unconscious awareness in a person with
Blind Sight
And
Blind Touch
Conscious mind and unconscious mind
Theories of consciousness and the soul.

28. Conclusion
 We show unconscious sensory
perception in a patient with sensory loss,
somatophrenia and neglect. This is a
new phenomenon similar to blind sight
and raises questions about unconscious
sensory perception.