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 wasn’t placed there

By the Big Printer in the sky

NEU CON NEU CON

NeuNeuConConCONTROVERSIES IN NEUROLOGYCONTROVERSIES IN NEUROLOGY

APRIL 3-4, 2010APRIL 3-4, 2010

G.ARJUNDASG.ARJUNDAS

Shri Uttambhai Nathalal Mehta1924 - 1998

A visionary par excellence

The pioneer of neuropsychiatry in India

The mind behind some of the blockbuster drugs in the neuropsychiatry segment; the founder and guiding force behind Torrent Group

A perfect epitome of business excellence, scientific integrity and benevolence unparalleled

SHRI US MEHTA ORATION

Thomas ElbertThomas Elbert

Cortical representation expands linearly with Cortical representation expands linearly with

use.use.

Synchronous inputs lead to fusion of cortical Synchronous inputs lead to fusion of cortical zoneszones

Asynchronous inputs lead to segregation of Asynchronous inputs lead to segregation of cortical zonescortical 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 Basic PrinciplesPrinciples

Sensory modulation in spatial Sensory modulation in spatial neglectneglect

Peripheral somatosensory- Magnetic Peripheral somatosensory- Magnetic stimulationstimulation

Repetitive optokinetic stimulation Repetitive optokinetic stimulation

Neck Vibration trainingNeck Vibration training

Drug Treatment is currently unsuccessful

Novel TechniquesNovel Techniques

Sensory modulation and Sensory modulation and StrokeStroke

Rehabilitation aimed to increase use of Rehabilitation aimed to increase use of paretic handparetic hand

Virtual reality Virtual reality

Motor imagery Motor imagery

Prof. Prof. V.S..Ramachandran’sV.S..Ramachandran’s virtual reality virtual reality boxbox

Phantom limb phenomenon Phantom limb phenomenon

Other techniquesOther techniques

Caloric tests for balanceCaloric tests for balance Brings awareness of illness to patient.Brings awareness of illness to patient.

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

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

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

BACKGROUNDBACKGROUND

Allesthesia and extinction of referral Allesthesia and extinction of referral sensation in brachial plexus lesions sensation in brachial plexus lesions A.V. Srinivasan and V.S. Ramachandran et al A.V. Srinivasan and V.S. Ramachandran et al (1998) (1998)

Intermanual referral of sensations Intermanual referral of sensations after central lesions of the somato after central lesions of the somato sensory system sensory system K. Sathian et al (2000) K. Sathian et al (2000)

METHODS METHODS

8 patients (19-51 years)8 patients (19-51 years) Brachial plexus lesion Brachial plexus lesion – one– one AmputationAmputation – two– two StrokeStroke – five– five

Patients were video filmed in the Patients were video filmed in the movement disorder clinic. Pinprick, cold, movement disorder clinic. Pinprick, cold, vibration and kinesthesis were testedvibration and kinesthesis were tested

MRI & ENMG in all cases MRI & ENMG in all cases

CENTRAL LESIONCENTRAL LESION

StrokeStrokeThalamic stroke Thalamic stroke - three- threeTemparo parietalTemparo parietal - two- two

Three to four months laterThree to four months later

Ipsilateral arm Ipsilateral arm - no referral- no referral to legto leg

STROKE STROKE Contd…Contd…

Intense pressure on the normal hand Intense pressure on the normal hand

resulted in extinction of pain in the resulted in extinction of pain in the

stroke sidestroke side

Pain returned within one Pain returned within one

minute of the pressure minute of the pressure

Intense pressure improved Intense pressure improved

sensory and motor sensory and motor

phenomenonphenomenon

AMPUTATIONAMPUTATION

Both the patients (below Both the patients (below

elbow & knee amputation) elbow & knee amputation)

showed intermanual showed intermanual

referral of sensation within referral of sensation within

10 days. The referred 10 days. The referred

sensations of touch and sensations of touch and

vibration lacked spatial vibration lacked spatial

organization and poor organization and poor

localization with a localization with a

relatively high threshold relatively high threshold

CASE VIGNETTE (BRACHIAL PLEXUS CASE VIGNETTE (BRACHIAL PLEXUS LESION)LESION)

21 year old girl, after total 21 year old girl, after total

brachial plexus lesion was brachial plexus lesion was

examined 6 months, 1 ½ & examined 6 months, 1 ½ &

2 ½ years after the lesion2 ½ years after the lesion

She had sensations She had sensations

intermanually referred in a intermanually referred in a

topographically organized topographically organized

manner in the phantom manner in the phantom

limb limb

INTERMANUAL REFERAL AND EXTINCTION OF INTERMANUAL REFERAL AND EXTINCTION OF PAIN SENSATIONPAIN SENSATION

Hemiparesis with Hemiparesis with hemisensory hemisensory

deficitdeficitAmputationAmputation

Brachial Brachial plexusplexus

Spatial organi-Spatial organi-sationsation

PoorPoor PoorPoor ExcellentExcellent

LocalisationLocalisation GoodGood PoorPoor ExcellentExcellent

Time of Time of occuranceoccurance

After 3 to 4 After 3 to 4 monthsmonths

Immediate Immediate with in 7 with in 7

daysdays

Immediate Immediate with in with in 7days7days

PainPainExtinction Extinction

After a delay of After a delay of

3 - 5 seconds3 - 5 secondsImmediateImmediate ImmediateImmediate

DISCUSSIONDISCUSSION

Anatomical facts Anatomical facts

1. Primary somato sensory area 3b1. Primary somato sensory area 3b

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

parietal operculumparietal operculum

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

DISCUSSION DISCUSSION Contd…Contd…

Contralateral referral of sensations Contralateral referral of sensations

was not found in normal subjects or in was not found in normal subjects or in

hemiparetic patients without hemi hemiparetic patients without hemi

sensory losssensory loss

Neural mechanisms for perceptual Neural mechanisms for perceptual

alteration not clear alteration not clear

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

DISCUSSION DISCUSSION Contd…Contd…

CONCLUSIONCONCLUSION

Intermanual referral & extinction of pain Intermanual referral & extinction of pain occurred immediately in amputation and occurred immediately in amputation and brachial plexus lesions and after a delay brachial plexus lesions and after a delay in strokein stroke

Intermanual referral of sensation Intermanual referral of sensation occurred topographicaly organised occurred topographicaly organised manner in brachial plexus lesions but not manner in brachial plexus lesions but not in amputation and strokein amputation and stroke

Hemineglect Hemineglect An Interesting Case An Interesting Case

fromfromProf.A.V.Srinivasan’s Prof.A.V.Srinivasan’s

UnitUnit

Can the mind believe Can the mind believe what the eye sees ?what the eye sees ?

On vision, visuospatial On vision, visuospatial

dysfunction and body image dysfunction and body image

perception in right perception in right

hemispherical dysfunctionhemispherical dysfunctionDr.K.Bijoy MenonDr.K.Bijoy Menon (Senior Resident)(Senior Resident)

Dr.Sundar, Dr.Saravanan, Dr.Sundar, Dr.Saravanan, Dr.RamakrishnanDr.Ramakrishnan

Dr.Nithyanandan (Asst.Prof) , Dr.Nithyanandan (Asst.Prof) ,

Prof. A.V.SrinivasanProf. A.V.Srinivasan

We thankWe thank Prof. V.S.RamachandranProf. V.S.Ramachandran, M.D., Ph.D., , M.D., Ph.D.,

Director Director

Centre for Brain and Cognitive Sciences Centre for Brain and Cognitive Sciences

University of California, San Diego, USAUniversity of California, San Diego, USA

Indrani. 50 year old femaleIndrani. 50 year old female

Presents with sudden onset of Presents with sudden onset of weakness of left upper and lower weakness of left upper and lower limblimb

O/E. O/E. Conscious, oriented to time, place and Conscious, oriented to time, place and

person person Mild left UMN facial paresisMild left UMN facial paresisLeft hemiplegiaLeft hemiplegiaAll peripheral pulses palpable All peripheral pulses palpable

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

Higher mental function evaluation Higher mental function evaluation

MMSE : 28/30MMSE : 28/30

She was very attentive and quite clear in She was very attentive and quite clear in her conversation with us, though she her conversation with us, though she would be complaining of a vague left sided would be complaining of a vague left sided shoulder painshoulder pain

On lobar testing, she hadOn lobar testing, she had

Left visual neglect with (L) hemianopiaLeft visual neglect with (L) hemianopia

No auditory neglectNo auditory neglect

Absent sensory perception in (L) upper Absent sensory perception in (L) upper limb and (L) tactile neglect in the lower limb and (L) tactile neglect in the lower limb limb

On cold caloric tests and its effect on neglectOn cold caloric tests and its effect on neglect

Video of NeglectVideo of Neglect

Video of caloric test and NystagmusVideo of caloric test and Nystagmus

Video of disappearance of neglect Video of disappearance of 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

On Anosognosia, Body neglect On Anosognosia, Body neglect (Hemisomatognosia) and (Hemisomatognosia) and somatoparaphreniasomatoparaphrenia

Anosognosia – our patient has itAnosognosia – our patient has it

Body neglect by Bisiach’s test – our Body neglect by Bisiach’s test – our patient does not have itpatient does not have it

Somatoparaphrenia – our patient has itSomatoparaphrenia – our patient has it

SomatoparaphreniaSomatoparaphrenia

On the somatophrenic arm and mirrorsOn the somatophrenic arm and mirrors

On Allesthesia, tactile neglect and ‘blind On Allesthesia, tactile neglect and ‘blind

touch’touch’

‘‘Touch your left arm’ Bisiach’s test of body Touch your left arm’ Bisiach’s test of body

neglect.neglect.

Absent proprioception and touch in the left Absent proprioception and touch in the left

upper limbupper limb

Patient is still able to touch her left arm Patient is still able to touch her left arm

whatever position the examiner keeps the whatever position the examiner keeps the

arm in.arm in.

Blind Sight Vs Blind TouchBlind Sight Vs Blind Touch

On visual imagery, neglect and caloric On visual imagery, neglect and caloric

tests tests

Visual imageryVisual imagery

Bisiach’s testBisiach’s test

Our testOur test

ResultsResults

Unconscious awareness in a person with Unconscious awareness in a person with

Blind Sight Blind Sight

And And

Blind TouchBlind Touch

Conscious mind and unconscious mindConscious mind and unconscious mind

Theories of consciousness and the soul.Theories of consciousness and the soul.