Prof. A.V. SRINIVASAN

Click here to load reader

download Prof. A.V. SRINIVASAN

of 45

  • date post

    30-Dec-2015
  • Category

    Documents

  • view

    37
  • download

    0

Embed Size (px)

description

The sign wasn. ’. t placed there. By the Big Printer in the sky. Prof. A.V. SRINIVASAN. Prof. A.V. SRINIVASAN. M.D, D.M, PhD. ,. F.I.A.N, F.A.A.N. ,. M.D, D.M, PhD. ,. F.I.A.N, F.A.A.N. ,. EMERITUS PROFESSOR OF NEUROLOGY. EMERITUS PROFESSOR OF NEUROLOGY. - PowerPoint PPT Presentation

Transcript of Prof. A.V. SRINIVASAN

  • NEU CON

    NeuCon

    CONTROVERSIES IN NEUROLOGYAPRIL 3-4, 2010

    G.ARJUNDAS

  • SHRI US MEHTA ORATION

  • Shri Uttambhai Nathalal Mehta 1924 - 1998

    A visionary par excellenceThe pioneer of neuropsychiatry in IndiaThe mind behind some of the blockbuster drugs in the neuropsychiatry segment; the founder and guiding force behind Torrent GroupA perfect epitome of business excellence, scientific integrity and benevolence unparalleled

  • Thomas Elbert

    Cortical representation expands linearly with use.

    Synchronous inputs lead to fusion of cortical zones

    Asynchronous inputs lead to segregation of cortical zones.

    Disuse or De-afferentation leads to invasion of unused cortical area by nearby neurons.

  • Sensory modulation in spatial neglect

    Peripheral somatosensory- Magnetic stimulation

    Repetitive optokinetic stimulation

    Neck Vibration training

  • Sensory modulation and Stroke Rehabilitation aimed to increase use of paretic hand

    Virtual reality

    Motor imagery

    Prof. V.S..Ramachandrans virtual reality box

    Phantom limb phenomenon

  • Other techniques Caloric tests for balance Brings awareness of illness to patient.

    Kinesthetic, visual, and auditory cues to improve Parkinsonian gait.

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

  • BACKGROUNDAllesthesia 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 K. Sathian et al (2000)

  • METHODS 8 patients (19-51 years)Brachial plexus lesion oneAmputation twoStroke five

    Patients were video filmed in the movement disorder clinic. Pinprick, cold, vibration and kinesthesis were testedMRI & ENMG in all cases

  • CENTRAL LESIONStrokeThalamic stroke - threeTemparo parietal- two

    Three to four months later

    Ipsilateral arm - no referral to leg

  • STROKE ContdIntense pressure on the normal hand resulted in extinction of pain in the stroke sidePain returned within one minute of the pressure Intense pressure improved sensory and motor phenomenon

  • AMPUTATIONBoth 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

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

  • INTERMANUAL REFERAL AND EXTINCTION OF PAIN SENSATION

    Hemiparesis with hemisensory deficitAmputationBrachial plexus

    Spatial organi-sationPoorPoorExcellent

    LocalisationGoodPoorExcellent

    Time of occuranceAfter 3 to 4 monthsImmediate with in 7 daysImmediate with in 7daysPainExtinction After a delay of 3 - 5 secondsImmediateImmediate

  • DISCUSSIONAnatomical facts

    1. Primary somato sensory area 3b

    2. A. Primary somato sensory area 1 & 22. B. Second somato sensory cortex and parietal operculum

    In 2a & 2b the receptive fields are largerbilateral and callosal connection areabundant

  • DISCUSSION ContdContralateral referral of sensations was not found in normal subjects or in hemiparetic patients without hemi sensory loss

    Neural mechanisms for perceptual alteration not clear

  • 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

  • CONCLUSIONIntermanual 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

  • Hemineglect An Interesting Case fromProf.A.V.Srinivasans Unit

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

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

  • Indrani. 50 year old femalePresents with sudden onset of weakness of left upper and lower limbO/E. Conscious, oriented to time, place and person Mild left UMN facial paresisLeft hemiplegiaAll peripheral pulses palpable

  • CT Brain P Shows a (R) Occipitotemporal infarct

  • Higher mental function evaluation MMSE : 28/30She 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 hadLeft visual neglect with (L) hemianopiaNo auditory neglectAbsent sensory perception in (L) upper limb and (L) tactile neglect in the lower limb

  • 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 AgnosiaMirror Agnosia on the Right

  • After caloric test, Mirror Agnosia on the Left

  • Mirror Agnosia to front

  • On Anosognosia, Body neglect (Hemisomatognosia) and somatoparaphreniaAnosognosia our patient has itBody neglect by Bisiachs test our patient does not have itSomatoparaphrenia our patient has it

  • Somatoparaphrenia

  • On the somatophrenic arm and mirrors

  • On Allesthesia, tactile neglect and blind touchTouch your left arm Bisiachs test of body neglect.Absent proprioception and touch in the left upper limbPatient 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 imageryBisiachs testOur test

  • Results

  • Unconscious awareness in a person with

    Blind Sight And Blind Touch

    Conscious mind and unconscious mind Theories of consciousness and the soul.