Download - Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

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Page 1: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Left movement Right movement Resting

Normal

M: LeftTrap RightTRap-200

0

200

400

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D_

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NonAHP

M: LeftTrap RightTRap

AHP

M: LeftTrap RightTRap

Controllo normale

1. Durante il reaching con il braccio sinistro si attiva LeftTrap

2. During il reaching con il braccio destro si attiva il RightTrap

Left movement

Right movement - - - - - - -

Resting ..……….

MUSCLES

ACTIVITY

μV

Page 2: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Left movement Right movement Resting

Normal

M: LeftTrap RightTRap-200

0

200

400

600

800

1000

1200V

D_

1

NonAHP

M: LeftTrap RightTRap

AHP

M: LeftTrap RightTRap

NonAHP

1. Durante il reaching sn si attiva il LeftTrap

2. Durante il reaching ds si attiva il RightTrap

Left movement

Right movement - - - - - - -

Resting ..……….

MUSCLES

ACTIVITY

μV

Page 3: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Left movement Right movement Resting

Normal

M: LeftTrap RightTRap-200

0

200

400

600

800

1000

1200V

D_

1

NonAHP

M: LeftTrap RightTRap

AHP

M: LeftTrap RightTRap

Left movement

Right movement - - - - - - -

Resting ..……….

MUSCLES

ACTIVITY

μV

Page 4: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Left movement Right movement Resting

Normal

M: LeftTrap RightTRap-200

0

200

400

600

800

1000

1200V

D_1

NonAHP

M: LeftTrap RightTRap

AHP

M: LeftTrap RightTRap

Left movement

Right movement - - - - - - -

Resting ..……….

Paziente AHP.

1. Durante il reaching sn si attiva il LeftTrap

2. Durante il reaching ds si attiva il RightTrap is activated3. Durante il reaching sn il RightTrap è più attivo del sn. Però la parte destra è sempre più attiva della sinistra (anche nella condizione di risposo; probabilmente ‘an active process induced by disinhibition, in order to establish new compensatory pathways’ see Ghika et al., 1995; Cao et al., 1998)

Page 5: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.
Page 6: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

CONCLUSION

From the activity registered in the proximal muscles of the affected side we can infer that AHP patient had, similarly to normal subjects, the intention to move

Next question would be: is this intentional response related to the operation of neural mechanisms that govern normal motor behaviour so to influence the motor performance of the intact hand when the patients try to execute bimanual movements?

Page 7: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

We decided to use a paradigm proposed by Kelso and coworkers in which the subjects had to reach for easy target (near and large) and difficult target (far and small).

They found that the Movement Time was much shorter for easy target than for difficult target in unimanual performance.

However, when the two conditions were combined they did not find that the limb producing a short movement to an easy target arrived earlier than the limb producing the

difficult movement.

there was a strong tendency for both movements to be initiated and terminated synchronously. In particular, the hand moving to the easy target slowed down when moving with the hand going to the difficult target.

Page 8: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

The question is: what happens when an hemiplegic patient with anosognosia, who cannot move the contralesional hand, but is convinced of being able to move it, is asked to perform unimanual and bimanual asymmetric movements?

Page 9: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

We slightly modified this paradigm to adapt it to right brain-damaged patients. In the Kelso et al. experiments targets were positioned to the right and left of the starting positions. In our paradigm the targets were positioned on the radial plane to minimise the interaction with visual neglect.

easy

difficult

Hand (Left or Right)

Space (Near or Far)

Action (Unimanual, Ba, Bs)

-normal subjects

-patient with AHP

Page 10: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

RESULTS IN NORMAL SUBJECTS

Transport time for the left and right hand as function of Space and Action

Far Near

Left hand

Action U Ba Bs100

200

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900

Mo

vem

ent

Tim

e

Right hand

Action U Ba Bs

1. LH and RH had similar MT in unimanual condition

Movement Time is much shorter for easy target than for difficult target in unimanual conditions.

1. In bimanual condition the hands’ reaching is simultaneous.

2. In Ba conditions

the hand that reaches for near targets slowed down.

Conclusion: the hands were influenced by the simultaneous acting of the other hand in asymmetrical conditions.

Page 11: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Predictions

• When patients with AHP are asked to perform bilateral reaching movements

They should not attempt bilateral hands movements

No difference in the MT of the R hand in the different conditions of the experiment

No intentionNo intention IntentionIntention

They should attempt bilateral movements

MT of the R hand in the Unilateral and Bilateral conditions should differ

Page 12: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Case report: Patient LM

41-year-old right-handed man

damage in the right hemisphere caused left hemiplegia, left hemianaesthesia and severe personal and extrapersonal left-sided neglect.

We tested him 71 days after the stroke

Well oriented in time and space

had no global reasoning or language problems. He could readily understand and follow test instructions and was very cooperative.

Page 13: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

At the time of testing he still showed left hemiplegia and left anaesthesia, whereas personal and extrapersonal neglect were improved

He also showed a severe ansognosia for hes hemiplegia Like CR he believed that he was able to use his left arm and hand and to walk and carry out without any problem several daily activities

Page 14: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.
Page 15: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Patient and controls’ right hand

Far Near

Patient

ACTION: UR Ba Bs0

200

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Mov

emen

t T

ime

Controls

ACTION: UR Ba Bs

- Also in patient LM the action of the right hand in near space is influenced by the simultaneous ‘perceived’ action of the contralesional plegic hand

Page 16: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.
Page 17: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

The intention was not an abstract will related to the previous knowledge of being able to move, but was actually implemented in the muscles fibers activated by the spared cortical circuits for motor programming and movement execution

goes so far as to influence the motor parameter of the right hand when the patients has the false belief of simultaneously moving the left hand.

These experiments strongly suggest that AHP patients do have the intention to move the plegic limb

Page 18: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Next steps

studiare aspetti bimanuali puramente motori studiare coinvolgimento distale attraverso lo studio cinematico del grasping

Page 19: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

1. aspetti bimanuali puramente motori

Page 20: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.
Page 21: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Planner (movement selection)

Limb World

Sensory Information/actual state

Goals/Prior intention

Efference copy

Forward model (Movement predictor/predicted state)

BSense of agency

A Comparator

Urge to move/intention Cx

x

Desired state

Motor awareness

comparator

affordances

In A, the comparator; in B, the predictor; in C, the locus of emergence of intention to move. According to our hypothesis:

1. a damage to the comparator that has to match the prediction with the actual state of the system prevents the detection of the difference between the movement/no movement conditions.

2. A part of the motor system functions normally. Patients have intentions and make predicitons. This leads to the construction of a non-veridical motor awareness that may represent the bases of the firm belief of being still able to move.

The discrepancy is not detected

Anosognosia

comparator

Berti and Pia, 2007

Page 22: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Gabriella Bottini Department of Pyshcology, University of Pavia

Eraldo Paulesu Department of Pyshcology, University of Milano Bicocca

Martina Gandola Department of Pyshcology, University of Pavia

Nicola Smania Rehabilitation Unit, Verona Hospital

Andrea Stracciari Neurology Unit, Sant’Orsola Hospital, Bologna

Lorenzo Pia

Lucia SpinazzolaDepartment of Pyshcology, Turin University

Grazie a voi e a:

Page 23: Controllo normale 1.Durante il reaching con il braccio sinistro si attiva LeftTrap 2.During il reaching con il braccio destro si attiva il RightTrap Left.

Goals/Prior intention

Sense of agency

Urge to move/intention

Motor awareness

affordances