Unconscious sensory perception in a case of hemineglect
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Transcript of Unconscious sensory perception in a case of hemineglect
Unconscious Sensory Perception in a Case of Hemineglect
Authors:
Ramachandran S. VilayanurSrinivasan V. Avathvadi
Bijoy K. Menon, Nithyanandam V. Allimuthu, Diane R. Rogers
Monday, October 9, 2006 Poster Session II
M65
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
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 paresisLeft hemiplegiaAll peripheral pulses palpable
Designs/Methods
CT Brain – P – Shows a (R) Occipitotemporal infarct
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
Designs/Methods
Our patient had (L) hemiplegia, (L) somatosensory loss with (R) temperooccipital infarct. Neuropsychological evaluation revealed the following.
On cold caloric tests and its effect on neglect
Video of Neglect
Video of caloric test and Nystagmus
Video of disappearance of neglect
On ‘ Mirror Agnosia’Mirror Agnosia on the Right
After caloric test, Mirror Agnosia on the Left
‘Mirror Agnosia’ to front
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
Somatoparaphrenia
On the somatophrenic arm and mirrors
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.
Blind Sight Vs Blind Touch
On visual imagery, neglect and caloric
tests
Visual imagery
Bisiach’s test
Our test
Results
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.
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.
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.
Discussion
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.
Unconscious awareness in a person with
Blind Sight
And
Blind Touch
Conscious mind and unconscious mind
Theories of consciousness and the soul.
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.