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Prof. A.V. SRINIVASAN. M.D, D.M, PhD,F.I.A.N, F.A.A.N, EMERITUS PROFESSOR OF NEUROLOGY FORMER HEAD AND PROFESSOR OF NEUROLOGY Institute of Neurology Chennai.

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Presentation on theme: "Prof. A.V. SRINIVASAN. M.D, D.M, PhD,F.I.A.N, F.A.A.N, EMERITUS PROFESSOR OF NEUROLOGY FORMER HEAD AND PROFESSOR OF NEUROLOGY Institute of Neurology Chennai."— Presentation transcript:

1 Prof. A.V. SRINIVASAN. M.D, D.M, PhD,F.I.A.N, F.A.A.N, EMERITUS PROFESSOR OF NEUROLOGY FORMER HEAD AND PROFESSOR OF NEUROLOGY Institute of Neurology Chennai Prof. A.V. SRINIVASAN. M.D, D.M, PhD,F.I.A.N, F.A.A.N, EMERITUS PROFESSOR OF NEUROLOGY FORMER HEAD AND PROFESSOR OF NEUROLOGY Institute of Neurology Chennai The sign wasnt placed there By the Big Printer in the sky

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3 NEU CON NeuCon CONTROVERSIES IN NEUROLOGY APRIL 3-4, 2010 G.ARJUNDAS

4 SHRI US MEHTA ORATION

5 Thomas Elbert Cortical representation expands linearly with use. Cortical representation expands linearly with use. Synchronous inputs lead to fusion of cortical zones Synchronous inputs lead to fusion of cortical zones Asynchronous inputs lead to segregation of cortical zones. Asynchronous inputs lead to segregation of cortical zones. Disuse or De-afferentation leads to invasion of Disuse or De-afferentation leads to invasion of unused cortical area by nearby neurons. unused cortical area by nearby neurons. Basic Principles Basic Principles

6 Sensory modulation in spatial neglect Peripheral somatosensory- Magnetic stimulation Peripheral somatosensory- Magnetic stimulation Repetitive optokinetic stimulation Repetitive optokinetic stimulation Neck Vibration training Neck Vibration training Drug Treatment is currently unsuccessful Novel Techniques

7 Sensory modulation and Stroke Rehabilitation aimed to increase use of paretic hand Rehabilitation aimed to increase use of paretic hand Virtual reality Virtual reality Motor imagery Motor imagery Prof. V.S..Ramachandrans virtual reality box Prof. V.S..Ramachandrans virtual reality box Phantom limb phenomenon Phantom limb phenomenon

8 Other techniques Caloric tests for balance Caloric tests for balance Brings awareness of illness to patient. Brings awareness of illness to patient. Kinesthetic, visual, and auditory cues to improve Parkinsonian gait. Kinesthetic, visual, and auditory cues to improve Parkinsonian gait.

9 INTERMANUAL REFERRAL OF SENSATION AND EXTINCTION OF PAIN IN PERIPHERAL AND CENTRAL LESIONS OF SOMATO SENSORY SYSTEM

10 BACKGROUND Allesthesia and extinction of referral sensation in brachial plexus lesions Allesthesia and extinction of referral sensation in brachial plexus lesions A.V. Srinivasan and V.S. Ramachandran et al (1998) Intermanual referral of sensations after central lesions of the somato sensory system Intermanual referral of sensations after central lesions of the somato sensory system K. Sathian et al (2000)

11 METHODS 8 patients (19-51 years) Brachial plexus lesion – one Brachial plexus lesion – one Amputation– two Amputation– two Stroke – five Stroke – five Patients were video filmed in the movement disorder clinic. Pinprick, cold, vibration and kinesthesis were tested Patients were video filmed in the movement disorder clinic. Pinprick, cold, vibration and kinesthesis were tested MRI & ENMG in all cases MRI & ENMG in all cases

12 CENTRAL LESION Stroke Thalamic stroke - three Thalamic stroke - three Temparo parietal- two Temparo parietal- two Three to four months later Ipsilateral arm - no referral to leg Ipsilateral arm - no referral to leg

13 STROKE Contd… Intense pressure on the normal hand resulted in extinction of pain in the stroke side Intense pressure on the normal hand resulted in extinction of pain in the stroke side Pain returned within one minute of the pressure Pain returned within one minute of the pressure Intense pressure improved sensory and motor phenomenon Intense pressure improved sensory and motor phenomenon

14 AMPUTATION Both the patients (below elbow & knee amputation) showed intermanual referral of sensation within 10 days. The referred sensations of touch and vibration lacked spatial organization and poor localization with a relatively high threshold Both the patients (below elbow & knee amputation) showed intermanual referral of sensation within 10 days. The referred sensations of touch and vibration lacked spatial organization and poor localization with a relatively high threshold

15 CASE VIGNETTE (BRACHIAL PLEXUS LESION) 21 year old girl, after total brachial plexus lesion was examined 6 months, 1 ½ & 2 ½ years after the lesion 21 year old girl, after total brachial plexus lesion was examined 6 months, 1 ½ & 2 ½ years after the lesion She had sensations intermanually referred in a topographically organized manner in the phantom limb She had sensations intermanually referred in a topographically organized manner in the phantom limb

16 INTERMANUAL REFERAL AND EXTINCTION OF PAIN SENSATION Hemiparesis with hemisensory deficit Amputation Brachial plexus Spatial organi- sation PoorPoorExcellent LocalisationGoodPoorExcellent Time of occurance After 3 to 4 months Immediate with in 7 days PainExtinction After a delay of seconds ImmediateImmediate

17 DISCUSSION Anatomical facts 1. Primary somato sensory area 3b 2. A. Primary somato sensory area 1 & 2 2. B. Second somato sensory cortex and parietal operculum In 2a & 2b the receptive fields are larger bilateral and callosal connection are abundant

18 DISCUSSION Contd… Contralateral referral of sensations was not found in normal subjects or in hemiparetic patients without hemi sensory loss Contralateral referral of sensations was not found in normal subjects or in hemiparetic patients without hemi sensory loss Neural mechanisms for perceptual alteration not clear Neural mechanisms for perceptual alteration not clear

19 It appears that a decrease in somatosensory input to one cerebral hemisphere from the contralateral hand allows responsiveness of neurons in this hemisphere to moderately intense tactile stimuli on the ipsilateral hand to exceed perceptual threshold (which does not normally occur). DISCUSSION Contd…

20 CONCLUSION Intermanual referral & extinction of pain occurred immediately in amputation and brachial plexus lesions and after a delay in stroke Intermanual referral & extinction of pain occurred immediately in amputation and brachial plexus lesions and after a delay in stroke Intermanual referral of sensation occurred topographicaly organised manner in brachial plexus lesions but not in amputation and stroke Intermanual referral of sensation occurred topographicaly organised manner in brachial plexus lesions but not in amputation and stroke

21 Hemineglect An Interesting Case from Prof.A.V.Srinivasans Unit

22 Can the mind believe what the eye sees ? On vision, visuospatial dysfunction and body image perception in right hemispherical dysfunction Dr.K.Bijoy Menon (Senior Resident) Dr.Sundar, Dr.Saravanan, Dr.Ramakrishnan Dr.Nithyanandan (Asst.Prof), Prof. A.V.Srinivasan

23 We thank Prof. V.S.Ramachandran, M.D., Ph.D., Director Prof. V.S.Ramachandran, M.D., Ph.D., Director Centre for Brain and Cognitive Sciences University of California, San Diego, USA

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

25 CT Brain – P – Shows a (R) Occipitotemporal infarct CT Brain – P – Shows a (R) Occipitotemporal infarct

26 Higher mental function evaluation MMSE : 28/30 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 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 Left visual neglect with (L) hemianopia No auditory neglect No auditory neglect Absent sensory perception in (L) upper limb and (L) tactile neglect in the lower limb Absent sensory perception in (L) upper limb and (L) tactile neglect in the lower limb

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29 On cold caloric tests and its effect on neglect

30 Video of Neglect

31 Video of caloric test and Nystagmus

32 Video of disappearance of neglect

33 On Mirror Agnosia Mirror Agnosia on the Right

34 After caloric test, Mirror Agnosia on the Left

35 Mirror Agnosia to front

36 On Anosognosia, Body neglect (Hemisomatognosia) and somatoparaphrenia On Anosognosia, Body neglect (Hemisomatognosia) and somatoparaphrenia Anosognosia – our patient has it Anosognosia – our patient has it Body neglect by Bisiachs test – our patient does not have it Body neglect by Bisiachs test – our patient does not have it Somatoparaphrenia – our patient has it Somatoparaphrenia – our patient has it

37 Somatoparaphrenia

38 On the somatophrenic arm and mirrors

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

40 Blind Sight Vs Blind Touch

41 On visual imagery, neglect and caloric tests On visual imagery, neglect and caloric tests Visual imagery Visual imagery Bisiachs test Bisiachs test Our test Our test

42 Results

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

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