1. Extinction – an underdiagnosed phenomenon Rev PR Case Report
Patrick Urwin
Neurology ST3

2. 48 yr old R handed Reverend
Visiting Nottingham
Found unresponsive in bath 24/03/12
Left hemiparesis
Left hemisensory deficit
No PMHx / DHx
Rare EtOH / Non-smoker
FHx mother DVT post partum

3. Clinical Course CT brain CT angio distal right ICA occlusion
Thrombolysed

4. CT Brain 24hr post thrombolysis

5. MRI Brain on Day 5 post infarct
DWI
ADC

6. Repatriation Kingston Wd K&C 17/04/12 for rehabilitation
Femoral DVT 24/04/12
Enoxaparin
Warfarin commenced after 4/52
Vasculitis and thrombophilia screen negative
Homonomous hemianopia and left neglect reported in notes
Citalopram for post-stroke depression
Transferred to NeuroRehab 15/06/12
Normal visual fields on formal testing

11. Behavioural Assessment of Neglect, Azouvi
Forgets to groom or shave the left part of his/her face 1
Experiences difficulty in adjusting his/her left sleeve or slipper 3
Forgets to eat food on the left side of his/her plate
Forgets to clean the left side of his/her mouth after eating
Experiences difficulty in looking towards the left
Forgets about a left part of his/her body (e.g. forgets to put his/her upper limb on the armrest or his/her foot on the wheelchair rest, or forgets to use his/her left arm when he/she needs to)
Has difficulty in paying attention to noise ore people addressing him/her from the left
Collides with people or objects on the left side, such as doors or furniture (either while walking or driving a wheelchair)
Experiences difficulty in finding his/her way towards the left when travelling in familiar places or in the rehabilitation unit
n/a
Experiences difficulty finding his/her personal belongings in the room or bathroom when they are on the left side 2
18/30
Key: 0 = no neglect; 1= mild neglect; 2 = moderate neglect; 3 = severe neglect

12. * *
49935

13. Extinction testing Computerised test
Attention paid to centre of screen
Series of numbers displayed centrally
* flash up in peripheries up to two quadrants 100ms
Pt reports when * seen and where
Errors/omission noted
All omissions by PR on left when concurrent R stimulus

15. Search testing Alternative task Inverted T present in 50%
Pt reports present or absent
Observer records present on L, R or absent and calculates accuracy

16. GVS Trial PR given GVS by Dr. Wilkinson's team
Baseline measures Aug 2012
Repeat at 1/52 following sham GVS
2 further assessments after 5/7 GVS and 2/52 after

17. Increasing evidence of GVS benefit in neglect
E.g. Utz et al. Neuropsychologia Apr;49(5): :
“In neglect patients [...] GVS significantly
reduced the rightward line bisection error
as compared to baseline (without GVS)
and sham stimulation”

18. Unfortunately minimal benefit in PR's extinction
No improvement on computerised stimulus testing with *
Transient improvement in search task at end of GVS
Back to pre-GVS baseline after 1/52
No residual improvement in extinction when pt discharged to intermediate care Sept 2012

20. Neglect Graded defect Cf field loss (1° visual cortex)
Gradually declining awareness or performance moving towards contralesional side
Depends on head and thorax position
Cf field loss (1° visual cortex)
Clear borders, dependent on retinal position
Parietal spatial mapping
But loss of location in space causes loss of awareness of existence of items
Loss of other modalities of sensory information does not cause neglect
Is parietal function in attention to identify single next visual target?

21. Extinction No neglect when single stimulus offered
Requires multiple stimuli
Ipsilesional stimulation results in neglect of contralesional side
Relative relation between stimuli, even if both contralesional
Extinction less pronounced for stimuli with parallel pathways
Contralesional faces – fusiform gyrus
Contralesional spiders – limbic / amydala
Extinction in healthy subjects

22. Extinction vs Neglect ?Spectrum ?Different anatomy
Right inferior parietal lobe, affecting both dorsal and ventral visual processing pathways; implicated in both processes
No consensus in literature for anatomical explanation

23. Extinction vs Neglect Why make the diagnosis? Do we miss many?
Poorer prognosis in stroke pts with neglect
Tailored MDT rehab improves outcome in some patients with neglect
Potentially greater benefit with extinction therapy
Do we miss many?
up to 75% of pts with hemiparesis have neglect or extinction
Extinction can still have profound impact
Shopping
Driving
Crossing road

24. Kerkhoff et al. demonstrated a sustained improvement in tactile extinction in 2 patient with chronic deficits following GVS
Unfortunately, we have not demonstrated the same improvement with visual extinction in PR
Could there be a role of GVS in diagnosis of visual extinction?

25. Thanks to Dr David Wilkinson, Senior Lecturer in Psychology
& Olga Zubko, Research Associate

26. References
Driver J,Vuilleumier P. Perceptual awareness and its loss in unilateral neglect and extinction. Cognition. 2001; 79:
Kerkhoffa G, Hildebrandtb H, Reinharta S, Kardinala M, Dimovaa V, Utz KS. A long-lasting improvement of tactile extinction after galvanic vestibular stimulation: Two Sham-stimulation controlled case studies. Neuropsychologia Jan; 49(2): 186–195
Utz KS, Keller I, Kardinal M, Kerkhoff G. Galvanic vestibular stimulation reduces the pathological rightward line bisection error in neglect-a sham stimulation-controlled study. Neuropsychologia Apr; 49(5):
Vossel S, Eschenbeck P, Weiss PH, Weidner R, Saliger J, Karbe H, Fink GR. Visual extinction in relation to visuospatial neglect after right- hemispheric stroke: quantitative assessment and statistical lesion- symptom mapping. J Neurol Neurosurg Psychiatry. 2011; 82:
Wilkinson D, Zubko O, Degutis J, Milberg W, Potter J. Improvement of a figure copying deficit during subsensory galvanic vestibular stimulation. J Neuropsychol Mar; 4(1):