Table 4.
Studies on DBS for the treatment of tremor in MS
| Study | N* | patient characteristics | stimulation site | follow-up | tremor and disability assessment | patients with tremor reduction (%)§ | patients with improved functional status (%)§ | patients with permanent adverse effects (n) |
|---|---|---|---|---|---|---|---|---|
| Brice and McLellan, 1980 [17] | 2 | severe bilateral arm intention tremor | bilateral subthalamic | 5 mo 6 mo | clinical examination | 2 (100%) | 2 (100%) | ** |
| Nguyen and Degos, 1993 [71] | 1 | severe unilateral distal postural arm tremor | unilateral VIM | 17 mo | clinical tremor and functional rating scales | 1 (100%) | 1 (100%) | not reported |
| Siegfried and Lippitz, 1994 [88] | 9 | severe intention tremor | unilateral (n = 8) or bilateral (n = 1) VIM | not reported | not reported | 9 (100%) | not reported | not reported |
| Benabid et al. 1996 [13] | 4 | severe arm tremor† | VIM† | ≥ 6 mo | clinical tremor rating scale | 0 (0%)‡ | no detailed report† | intracerebral haemorrhage (1) |
| Geny et al. 1996 [41] | 13 | severe postural tremor (n = 12), moderate intention tremor (n = 1) | unilateral VIM | 8 to 26 mo mean: 13 mo | clinical tremor and functional rating scales | 9 (69%) | 12 (92%) | MS relapse (3) |
| Whittle et al. 1998 [99]*** | 5 | severe arm tremor | VL | not reported | not reported | not reported | not reported | not reported |
| Hay, 1999 [46] | 1 | head and limb tremor | unilateral thalamus | 2 mo | not reported | 1 (100%) | not reported | not reported |
| Montgomery et al, 1999 [66] | 14 | disabling arm tremor | unilateral VIM | variable | clinical tremor rating scale | 15 (100%) | not reported | MS relapse (1)# |
| Schulder et al. 1999 [83] | 5 | severe bilateral postural and intention arm tremor | unilateral VIM | >6 mo | clinical tremor rating scale, patient self assessment of functional improvement | 5 (100%) | 3 (60%) | Ms relapse (2) |
| Taha et al. 1999 [90] | 2 | bilateral limb, head or voice tremor† | bilateral VIM (bilateral DBS or unilateral DBS plus contralateral thalamotomy) | mean: 10 mo | clinical tremor rating scale | 2 (100%) | not reported | not reported separately for MS subgroup† |
| Schuurman et al. 2000 [85] | 5 | severe arm tremor | unilateral or bilateral VIM | 6 mo | clinical tremor and functional rating scales | 3–5 (60–100%)$ | 0 (0%) | dysarthria (2) severe gait or balance disturbance (1) arm ataxia (1) |
| Krauss et al. 2001 [53] Loher et al. 2003 [61]$$ | 2 | severe tremor | unilateral or bilateral VIM† | 3 to 24 mo, mean: 12 mo† | clinical tremor rating scales, assessment of video tapes | 2 (100%) | not reported | not reported separately for MS subgroup† |
| Matsumoto et al. 2001 [62] | 3 | severe tremor | unilateral VIM | 3 to 12 mo | clinical tremor and functional rating scales, novel movement analysis tool | 3 (100%) | 0 (0%) | none |
| Hooper et al. 2002 [49] | 10 | disabling arm tremor | unilateral thalamus | 12 mo | clinical tremor and functional rating scales | 10 (100%) | 0 (0%) | intracerebral haemorrhage (2) generalized seizure (2) |
| Nandi et al. 2002 [70] | 1 | severe bilateral postural and intention tremor | unilateral ZI | 12 mo | clinical examination | 1 (100%) | 1 (100%) | increased dystonic posturing of left foot impairing ambulation (1) |
| Berk et al. 2002 [14] | 12 | disabling arm tremor | unilateral VIM | 12 mo | clinical tremor and functional rating scales, patient self assessment questionnaire | significant tremor reduction, not individually reported | no significant improvement | wound infection (2) |
| Wishart et al. 2003 [102] | 4 | bilateral arm tremor | bilateral VL | 15 to 31 mo | clinical tremor rating scale | 4 (100%) | 4 (100%) | MS relapse (1) dysarthria (1) |
| Schulder et al. 2003 [84] | 9 | disabling arm tremor | unilateral thalamus | 9 to 48 mo, | clinical tremor and functional rating scales, patient self assessment | 8 (88%) | 3 (33%) | MS relapse (3) |
| Nandi et al. 2004 [69] | 10 | disabling arm tremor | unilateral (n = 6) or bilateral (n = 4) VOP and ZI | 3 to 23 mo | computer-aided tracking tasks | significant tremor reduction, not individually reported | not reported | seizure (1) dysarthria (1) wound infection (1) |
| Bittar et al. 2005 [15]y | 10 | disabling postural and intention arm tremor | unilateral VOP (distal tremor), unilateral ZI (proximal tremor) or unilateral VOP and ZI (mixed tremor) | 3 to 23 mo: | clinical tremor rating scale | not individually reported, overall improvement of mean tremor scores: postural: 64% intention: 36% | not reported | monoparesis (1) |
VIM = nucleus ventralis intermedius; ZI = zona incerta; VL = nucleus ventralis lateralis
* MS patients with completed surgical intervention and remaining in the study until the end of follow up
§ improvement as described in case reports or measured at the end of follow-up on any scale used in the study
** in this study two patients had complete surgery and in three, surgery was aborted. A worsening of dysarthria is reported in one patient, it is unclear whether this patients had completed surgery
*** This study mostly discusses difficulties in target localisation and patient selection
# in this study, one patient did not complete surgery due to an intraoperative VIM haemorrhage
† in this study, MS patients were grouped together with patients with other movement disorders, no details are given for the MS-subgroup
‡ For the whole group, tremor was “inconsistently, less significantly [than tremor of Parkinson’s Disease and essential tremor] or not improved. If improvement was achieved it lasted only a few months”
$ The exact number of patients with improved tremor cannot be ascertained the way the data is presented in this study
$$ Both studies are on one patient cohort, the relevant data on MS patients are derived from both studies