Unconscious sensory perception in a case of hemineglect
M65 Unconscious Sensor y Per ception in a Case of Hemine glect Authors: Ramachandran S. Vilayanur Srinivasan V. AvathvadiBijoy K. Menon, Nithyanandam V. Allimuthu, Diane R. Rogers Monday, October 9, 2006 Poster Session II
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
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
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 painOn 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/MethodsOur patient had (L) hemiplegia, (L)somatosensory loss with (R)temperooccipital infarct.Neuropsychological evaluation revealedthe following.
On cold caloric tests and its effect on neglect
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
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.
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.
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.
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 TouchConscious mind and unconscious mindTheories 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.