Deep Brain Stimulation for Tremor Associated with Underlying Ataxia Syndromes: A Case Series and Discussion of Issues

Genko Oyama; Amanda Thompson; Kelly D. Foote; Natlada Limotai; Muhammad Abd-El-Barr; Nicholas Maling; Irene A. Malaty; Ramon L. Rodriguez; Sankarasubramoney H. Subramony; Tetsuo Ashizawa; Michael S. Okun

doi:10.5334/tohm.180

Figures & Tables

Table 1

Pre- and Postoperative Validated Rating Scales for the Ataxia DBS Cases

Subject	Scale	Preop Score	6 Months Post DBS	12 Months Post DBS
SCA2	TRS: motor	51	DBS on: 31	DBS on: 26
SCA2	TRS: motor	51	DBS off: 35	DBS off: 33
FXTAS	TRS: motor	60	DBS on: 57	DBS on: 45
FXTAS	TRS: motor	60	DBS off: 60	DBS off: 62
Ataxia NOS	TRS: motor	40	DBS on: 27	N/A
Ataxia NOS	TRS: motor	40	DBS off: 29	N/A
SCA17	BFMDRS	15	DBS off 32	DBS on 17
SETX	UDRS	34	DBS on: 34	DBS on: 38
SETX	UDRS	34	DBS off: 35	DBS on: 38

[i] Ataxia NOS, Ataxia Not Otherwise Specified; BFMDRS, Burke–Fahn–Marsden Dystonia Rating Scale; DBS, Deep Brain Stimulation; FXTAS, Fragile X Ataxia Syndrome; SCA2, Spinocerebellar Ataxia Type 2; SCA17, Spinocerebellar Ataxia Type 17; SETX, Senataxin Mutation-associated Ataxia; TRS, Tremor Rating Scale; UDRS, Unified Dystonia Rating Scale.

Table 2

Postoperative Lead Locations for Ataxia DBS Patients

Subject	Target	Right	Left
SCA2	Vim		X 11.2, Y –6.4, Z –1.9
FXTAS	Vim		X –12.9, Y –9.9, Z –0.79
FXTAS	VOA		X –13.4, Y –7.89, Z –1.7
Ataxia NOS	Vim		X –13, Y –6.91, Z –3.5
SCA17	GPi	X 18, Y 1.8, Z –4.1	X –20.5, Y 1.8, Z –6.6
SETX	GPi	X 19.5, Y 0.71, Z –4.57	X –22, Y –0.3, Z –4.2

[i] Lead locations were derived from computed tomography–magnetic resonance imaging fusion.

[ii] Measurements were made in reference to the mid-commissural point: Y, anteroposterior; X, mediolateral; Z, axial; Vim, Thalamic Ventralis Intermedius Nucleus; GPi, Posteroventral Globus Pallidus Internus; VOA–VOP, Thalamic Ventralis Oralis Anterior and Ventralis Oralis Posterior.

[iii] Ataxia NOS, Ataxia Not Otherwise Specified; FXTAS, Fragile X Ataxia Syndrome; SCA2, Spinocerebellar Ataxia Type 2; SCA17, Spinocerebellar Ataxia Type 17; SETX, Senataxin Mutation-associated Ataxia.

Table 3

Deep Brain Stimulation Programming Settings for Ataxia Cohort

Subject	Target	Cathode(s) (−)	Anode (+)	Voltage (V)	Pulse Width (µs)	Frequency (Hz)	Postop Month
SCA2	Left Vim	2	C	1.8	90	135	12
FXTAS	Left VOA	2	C	3.3	120	135	12
FXTAS	Left Vim	6	C	3.3	150	135	12
Ataxia NOS	Left Vim	0	2	3.2	180	135	6
SCA17	Left GPi	1	3	3.2	450	185	12
SCA17	Right GPi	1	3	3.2	450	185	12
SETX	Left GPi	1	C	4.6	180	100	12
SETX	right GPi	1, 2	C	3.6	150	100	12

[i] Ataxia NOS, Ataxia Not Otherwise Specified; FXTAS, Fragile X Ataxia Syndrome; GPi, Globus Pallidus Interna; SCA2, Spinocerebellar Ataxia Type 2; SCA17, Spinocerebellar Ataxia Type 17; SETX, Senataxin Mutation-associated Ataxia; Vim, Ventralis Intermedius Nucleus; VOA, Ventralis Oralis Anterior.