Recovering Repressed Visual Memories and in Parietal Lobe Syndrome Using Vestibular Stimulation Authors: Srinivasan V. Avathvadi Bijoy K. Menon | Nithyanandam V. Allimuthu Rogers R. Diane | Ramachandran S. Vilayanur Monday, October 9, 2006 Poster Session II M48
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Recovering repressed visual memories and in parietal lobe syndrome using vestibular stimulation
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Recovering Repressed Visual Memories and in Parietal Lobe Syndrome
Using Vestibular StimulationAuthors:
Srinivasan V. AvathvadiBijoy K. Menon | Nithyanandam V. Allimuthu
Rogers R. Diane | Ramachandran S. Vilayanur
Monday, October 9, 2006 Poster Session II
M48
Recovering Repressed Visual Memories and in Parietal Lobe
Syndrome Using Vestibular Stimulation
Srinivasan V. Avathvadi, Bijoy K. Menon, Rogers R. Diane, Ramachandran S. Vilayanur
and Nityanandam V. Allimuthu Neurology, Institute of Neurology, Madras Medical College, Chennai,
Tamilnadu, India; Centre for Brain and Cognition, University California - San Diego, San Diego, CA
Objective: 1)Does vestibular stimulation through caloric test reverse neglect, mental imagery tasks and mirror
agnosia? Background:Unilateral neglect may be temporarily reduced by vestibular stimulation. Designs/Methods:
Our patient had Left hemiplegia,visual neglect, anosognosia. CT Brain showed right occipitoparieto temporal
infarct.She reported and pointed objects kept to her right and left side of her room ,before, during and after cold
caloric testing. Mental imagery was tested by blindfolding her She reached for the reflection of a pencil in a mirror
placed on right and the pencil was on left (dubbedmirror agnosia by VS Ramachandran and E.Altschuler)
Results : First she reported objects placed on her right. When cold caloric test in her left ear produced
nystagmus,her neglect disappeared.She reported all objects, when mental imagery was tested.After thirty
minutes, she could report and point to objects on her right only. When caloric test was repeated and during
mental imagery,she reported all objects. It eliminated neglect but not mirror agnosia .Conclusion:a) vestibular
stimulation eliminates neglect for mental imagery giving access to previously repressed inaccessible memories b)
Mirror agnosia is caused by right parietal damage rather than being a direct consequence of neglect.
Authors: Srinivasan V. Avathvadi | Bijoy K. Menon | Rogers R. Diane
Ramachandran S. Vilayanur | Nithyanandam V. Allimuthu
Monday, October 9, 2006 Poster Session II
Recovering Repressed Visual Memories and in
Parietal Lobe Syndrome Using Vestibular Stimulation
Bijoy K. Menon Nithyanandam V. AllimuthuRogers R. DianeRamachandran S. Vilayanur
Neglect has been defined as “the failure to report, respond, or orient to novel or meaningful stimuli presented to the side opposite a brain lesion, when this failure cannot be attributed to either sensory or motor defects.”
Category Memory and representational deficits Motor Neglect Sensory Neglect
Attentional orienting system Failure to construct a complete mental representation of
contralesional space Incidence
Stone et al 80% - visual neglect Denes et al 17% - unilateral spacial neglect – right CVA
Prognosis Poor outcome and lower scores on FIM
Does vestibular stimulation through caloric Does vestibular stimulation through caloric test reverse neglect, mental imagery tasks test reverse neglect, mental imagery tasks and mirror agnosia?and mirror agnosia?
Unilateral neglect may be temporarily Unilateral neglect may be temporarily reduced by vestibular stimulationreduced by vestibular stimulation
Objective and Background
Designs/Methods: Designs/Methods: Case Case vignettevignette
Our patient had Left Our patient had Left hemiplegia,visual neglect, hemiplegia,visual neglect, anosognosia. CT Brain showed anosognosia. CT Brain showed right occipitoparieto temporal right occipitoparieto temporal infarct. She reported and pointed infarct. She reported and pointed objects kept to her right and left objects kept to her right and left side of her room, before, during side of her room, before, during and after cold caloric testing. and after cold caloric testing.
Designs/Methods:Designs/Methods:
Mental imagery was tested by Mental imagery was tested by blindfolding her She reached for blindfolding her She reached for the reflection of a pencil in a mirror the reflection of a pencil in a mirror placed on right and the pencil was placed on right and the pencil was on left (dubbed mirror agnosia by on left (dubbed mirror agnosia by VS Ramachandran and E. VS Ramachandran and E. Altschuler) Altschuler)
On visual imagery, neglect and caloric tests On visual imagery, neglect and caloric tests
Visual imageryVisual imagery
Bisiach’s testBisiach’s test
Our testOur test
Video of caloric test and Nystagmus
Video of Neglect
Video of disappearanceof Neglect
On ‘ Mirror Agnosia’On ‘ Mirror Agnosia’Mirror Agnosia on the Right Mirror Agnosia on the Right
After caloric test, Mirror Agnosia on the LeftAfter caloric test, Mirror Agnosia on the Left
‘‘Mirror Agnosia’ to frontMirror Agnosia’ to front
Results :
First she reported objects placed on her right. When cold caloric test in her left ear produced nystagmus, her Neglect disappeared. She reported all objects, when mental imagery was tested.
Results :
After thirty minutes, she could report and point to objects on her right only. When caloric test was repeated and during mental imagery, she reported all objects. It eliminated neglect but not mirror agnosia.
Results
DiscussionDiscussion
Our patient had all the three major Our patient had all the three major categories of attentional deficit.categories of attentional deficit.
Vestibular stimulation improved all the Vestibular stimulation improved all the three categories temporarily till the three categories temporarily till the stimulation persisted.stimulation persisted.
After 30min - Neglect returnedAfter 30min - Neglect returned Mirror agnosia did not disappear.Mirror agnosia did not disappear.
Treatment of NeglectTreatment of Neglect
Attentional MechanismsAttentional Mechanisms– Training of attention - WeinvergTraining of attention - Weinverg– Activation of sustained attention systemActivation of sustained attention system
Representational Deficit – SmaniaRepresentational Deficit – Smania– Visual and movement imagery exercisesVisual and movement imagery exercises
Caloric Stimulation – Vallar GCaloric Stimulation – Vallar G– In our Patient, this stimulation are usedIn our Patient, this stimulation are used
Neural pathways responsible for remission following vestibular stimulation through caloric stimulation are unknown
vestibular stimulation eliminates neglect for mental
imagery giving access to previously repressed
inaccessible memories
Mirror agnosia is caused by right parietal damage
rather than being a direct consequence of neglect.
Conclusion:
a) vestibular stimulation eliminates neglect for mental imagery giving access to previously repressed inaccessible memories
b) Mirror agnosia is caused by right parietal damage rather than being a direct consequence of neglect.
We ThankWe Thank
Prof. V.S.RamachandranProf. V.S.Ramachandran, , M.D., Ph.D.,M.D., Ph.D.,
DirectorDirector Centre for Brain and Cognitive Sciences Centre for Brain and Cognitive Sciences
University of California, San Diego, USAUniversity of California, San Diego, USA
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