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Transcript of Hospital Central de Asturias Centro Universitario Unidad Multidisciplinar de los Trastornos del...
Hospital Central de AsturiasCentro UniversitarioUnidad Multidisciplinar de los Trastornos del Movimiento
Scalp evoked potentials induced by Therapeutic DBS of Subthalamic nucleus F. Fernández-González, F. Seijo, C. Vallés, B. Lozano, L. Guisasola, C. Salvador, A. Galindo
-Fz+Cz
-Cz-+Pz
-Pz+Oz
-Fpz+Fz
50 ms
Scalp evoked potentials
Therapeutic DBS-STN stimulation
R L
Hospital Central de AsturiasCentro Universitario
DBS - STN 1998 1999 2000 2001 2002 Total implants
Bilateral 3 4 12 25 11 90
Unilateral 6 0 6 5 2 19
Total patients 9 4 18 30 13+TOTAL 9 13 31 61 74+ 109
Movement Disorders Multidisciplinary Team
Pre - STN DBSOFF medication
Good Indication
Post - STN DBSON DBS - OFF Medication
Bad results?
6 months
N= 32 mA S Hz polemean 2.9 75.0 156.5 1.9 s.d. 0.6 20.4 25.6 0.7 min. 1.0 60.0 130.0 0.0 1th quar. 2.5 60.0 135.0 2.0 median 2.9 60.0 135.0 2.0 3th quar. 3.2 90.0 185.0 2.0 max. 4.0 120.0 185.0 3.0
0.3 a 0.4 mm
0.1 a 0.2 mm
1.0 mm
METHODOLOGYMETHODOLOGY
Monopolar G2 recording
G1
G2
Unitary RecordingUnitary Recording
Trigger threshold
From STN we can record neurons with single and bursting pattern,
From rostro-dorso-lateral Subthalamus we can record kinestethic unitary activities (32%).
The kinesthetic neurons are somatotopically organized.
Bipolar G1-G2 recording
G1
G2
Multiunitary RecordingMultiunitary Recording
1 Second
- 2 mm from AC-PC plane
- 3 mm from AC-PC plane
- 4 mm from AC-PC plane
- 5 mm from AC-PC plane
From rostro-dorso-lateral STN we can record a kinesthetic related multiunitary activity with a 4Hz pattern ( - 3 mm AC-PC plane) , descending 1 mm into the STN, the multiunitary
recording show different values ( an irregular pattern at 7-9 Hz)
Bipolar G1-G2 recording
G1
G2
Multiunitary RecordingMultiunitary Recording
1 Second
- 2 mm from AC-PC plane
- 3 mm from AC-PC plane
- 4 mm from AC-PC plane
- 5 mm from AC-PC plane
From Cortex (Cx) to Substantia Nigra pars reticulata
(SNr) two seconds of multiunitary neuronal activity
(bipolar recording) are recorded and stored in steps of
1 mm of the recording track, starting at cortex.
From the 2 sec. recording of multiunitary neuronal
activity the on line process calculates the integral of
the multiunitary one, and is plotted against the
distance to the target in a graphic that shows the
stereotactic angle of the electrode trajectory in the
sagital plane.
Right Hemisphere
Left Hemisphere
Cx STR CI STN SNr
Therapeutic tetraelectrodeTherapeutic tetraelectrode
7.5 mm
Intracerebral Extracraneal To the Electromyograph
G1
G2
Video 1 Video 2Video 3
Tetraelectrode StimulationTetraelectrode Stimulation
DisKinesias RigidityTremor
0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0
10
.0 7
.5 5
.0 2
.5 0
.0 -2
.5 -5
.0 -7
.5 -1
0.0
-12
.5 -1
5.0
-17
.5 -2
0.0
10
.0 7
.5 5
.0 2
.5 0
.0 -2
.5 -5
.0 -7
.5 -1
0.0
-12
.5 -1
5.0
-17
.5 -2
0.00 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0
Fp. 3(-3 IPC)
AC-PC Plane
Simulation of the electrical current diffusion by DBS monopolar stimulus.
Stimulus: 2mA, 100 secCurrent density = 0.02 mA/mm 2
2.5 mm
5.0 mm Stimulus: 5mA, 100 secCurrent density = 0.01 mA/mm 2
Is necesary a CD = 0.04 mA/mm2 to excite large axonsand a CD = 0.3 mA/mm2 to excite small ones.
0 1 2 3
Threshold to evoke motor responses(Sporadic motor responses)
polemean mA 3.0 3.5 4.3 5.3s.d. 1.2 1.2 1.6 1.8Motor evoked potential(Direct motor responses)
polemean mA 4.9 5.6 6.6 7.6s.d. 1.8 1.6 1.7 1.8
3210
3210
( x mA; 100 mS; 3 p.p.s)
Stimulation: DBS monopolar - 2 poleRecording: Ext. Dig. Communi’s rectified EMG
-40 -20 0.0 +20 +40 +60 +80 +100 +120 +140ms
60V
58.8ms 12.6ms
1.7mA
1.9mA
2.1mA
2.3mA
2.5mA Subthreshol
2.9mA
3.4mA
3.8mA Motor threshold
4.1mA
4.3mA
4.4mA
4.5mA
4.6mA Motor response
4.7mA
4.9mA
5.0mA
Data from 64 implants
N = 18Set A : < 2.5 mA
N = 14Set B : > 2.5 mA
Stimulus intensity needed to induce Motor threshold on Ext.Dig.Comm.
Linear correlation (Motor threshold)
- 0.9 0.7 0.50.9 - 0.7 0.60.7 0.7 - 0.90.5 0.6 0.9 -
<0.001 <0.001 <0.001 <0.001
Therapeutic DBS parameters
mA mS Hz Pole <0.05 <0.001 <0.01 >0.05
p
p
Mean differencesSet A versus Set B
Stimulus intensity needed to induce Motor threshold
2.0 2.5 3.4 4.3 0.5 0.7 1.0 1.7
Therapeutic DBS parameters
mA mS Hz Pole 2.7 58.8 143.3 1.9 0.6 14.3 20.3 0.6
MeanS.D.
MeanS.D.
Set A ( N = 18)
Stimulus intensity needed to induce Motor threshold
3.7 4.1 4.9 5.9 1.1 0.9 1.6 1.5
Therapeutic DBS parameters
mA mS Hz Pole 3.1 82.1 166.1 1.7 0.4 30.4 26.4 0.7
MeanS.D.
MeanS.D.
Set B ( N = 14)
5.0
TOTAL PatientsNumber = 32Median values = 3.8 3.0 2.5 mA
x mA100 S3 pps TOTAL
Number = 32
S.I. 10-20FpzFz
Cz
Pz
Oz
P4
C4
F4Fp2
-Fz+Cz
-Cz-+Pz
-Fpz+Fz
-Pz+Oz
100 ms -Fz+Cz
-Cz-+Pz
-Pz+Oz
-Fpz+Fz
50 ms
-Fpz+Fz
25 ms
40uV
5.5 ms 7 a 12 ms 75 ms
0 1 2 3
STN monopolar stimulation
Are this cortical recorded components EMG artefacts?
Stimulation: DBS monopolar - 2 poleRecording: Ext. Dig. Communi’s rectified EMG
-40 -20 0.0 +20 +40 +60 +80 +100 +120 +140ms
60V
58.8ms 12.6ms
1.7mA
1.9mA
2.1mA
2.3mA
2.5mA Subthreshol
2.9mA
3.4mA
3.8mA Motor threshold
4.1mA
4.3mA
4.4mA
4.5mA
4.6mA Motor response
4.7mA
4.9mA
5.0mA
5.3 mSecMasseter
8.4 mSecBorla mentonniana
13.2 mSecExt. Dig. Comm.
0 1 2 3
-Fpz+Fz
25 ms
40 V
5.5ms 7 a 12 ms 75ms
Stim.
0 1 2 3
S.I. 10-20FpzFz
Cz
Pz
Oz
P4
C4
F4Fp2
Mínimal1.1 mA
STIMULATION: Monopolar DBS-STN Tetraelectrode: 2Subminimal0.6 mARECORDING:A) Ext.Dig.Comm. Integrated EMG
B) Scalp evoked potentials
Subthreshold2.3 mA
Motor threshold4.6 mA
Direct motor responsesSporadic motor responsesNO motor responsesNO motor responses
N= 32 mA S Hz pole
mean 2.9 75.0 156.5 1.9 s.d. 0.6 20.4 25.6 0.7
Remember: therapeutic values
40uV
20 ms
Fpz - Fz
Fz - Cz
Cz - Pz
Pz - Oz
NO scalp responses Scalp evoked responses Scalp evoked responses
Fpz - Fz
Fz - Cz
Cz - Pz
Pz - Oz
Fpz - Fz
Fz - Cz
Cz - Pz
Pz - Oz
S.I. 10-20FpzFz
Cz
Pz
Oz
P4
C4
F4Fp2
+4
+0
-2-4
-6
+620 ms
+2
Stimulation:Bipolar 500 A; 100 s
0.3 a 0.4 mm
0.1 a 0.2 mm
1.0 mm
Trajectory
Target
Based in Parent (1998)
2 a 3 2 a 3
2 a 3
2 a 3
Ramón y Cajal (1906)
Capsula interna (2 a 3 )
Lenticular fasciculus or Forel’s field H2) (2 a 3 )
Subthalamic fasciculus (2 a 3 )
Ansa lenticilaris, Thalamic fasciculus or Forel’ H1. (2 a 3 )
Zona Incerta
Subthalamic nucleus
Cerebral peduncule
Hospital Central de AsturiasCentro UniversitarioUnidad Multidisciplinar de los Trastornos del Movimiento
S.I. 10-20FpzFz
Cz
Pz
Oz
P4
C4
F4Fp2
Ejemplo mapping: N. Mediano dcho.
Mapping de la activación cortical inducida por el estimulo umbral motor (3.5 mA) del núcleo Subtalámico derecho,aplicado como estimulaciónbipolar con cátodo en el polo 2 del tetraelectrodo implantado
Umbral motor
20ms
40uV
S.I. 10-20FpzFz
Cz
Pz
Oz
P4
C4
F4Fp2
Ejemplo mapping por estimulacióna nivel del núcleo Subtalámico Izdo, por estimulo bipolar con cátodo en el polo 2 del tetraelectrodo implantado
0 a 40 ms 252 a 292 ms 336 a 502 ms
Ejemplo mapping: Estimulo N. Mediano derecho
Ejemplo mapping: Estimulo n. Subtalámico izquierdo