Table 1
Demographics, clinical profile, surgical interventions and comparison between DBS and lesioning surgery.
| VARIABLES(N,% OR MEAN ± S.D) | TOTAL | LESIONING | DBS | REMARKS |
|---|---|---|---|---|
| Number of patients | 17 | 8 | 9 | |
| Mean age at onset (y) | 13.7 ± 8.9 | 13.5 ± 7.2 | 18.8 ± 10.9 | |
| Mean age at surgery (y) | 19.8 ± 9.7 | 21.0 ± 8.7 | 19.2 ± 11.6 | |
| Mean duration of illness before surgery (y) | 5.9 ± 3.7 | 6.5 ± 5.2 | 4.8 ± 1.8 | |
| Underlying diagnosis | ||||
| Wilson’s disease | 8 (47.1%) | 6 (75%) | 2 (22.2%) | |
| NBIA spectrum disorder | 5 (29.4%) | 2 (25%) | 3 (33.3%) | |
| DYT-TOR1A | 1 (5.9%) | 0 | 1 (11.1%) | |
| Neuroacanthocytosis | 1 (5.9%) | 0 | 1 (11.1%) | |
| Niemann-Pick disease type C | 1 (5.9%) | 0 | 1 (11.1%) | |
| Giles de la Tourette syndrome | 1 (5.9%) | 0 | 1 (11.1%) | |
| Indication for surgery@ | ||||
| Generalized dystonia | 11 (64.7%) | 4(50%) | 7 (77.8%) | |
| Tremors | 5 (29.4%) | 5(62.5%) | 0 | |
| Generalized chorea | 1 (5.9%) | 0 | 1 (11.1%) | |
| Complex motor tics | 1 (5.9%) | 0 | 1 (11.1%) | |
| Type surgery | ||||
| Unilateral ViM thalamotomy | 4 (23.5%) | 4 (50%) | NA | |
| (Rt-1, Lt-3) | ||||
| Bilateral ViM thalamotomy | 1 (5.9%) | 1 (12.5%) | NA | |
| Bilateral pallidotomy | 3 (17.7%) | 3 (37.5%) | NA | |
| Bilateral GPi DBS | 9 (52.9%) | NA | 9 (100%) | |
| Complications | ||||
| Speech impairment | 7 (41.2%) | 4 (44.4%) | 1 (12.5%) | |
| Swallowing difficulty | 3 (17.7%) | 3 (33.3%) | 0 | |
| Movement disorder | ||||
| – Blepharospasm | 3 (17.7%) | 1 (11.1%) | 2 (25.0%) | |
| – Status dystonicus | 1 (5.9%) | 1 (11.1%) | 0 | |
| – Persistent dystonia | 5 (29.4%) | 2 (22.2%) | 3 (37.5%) | |
| – Persistent choreiform movements | 1 (5.9%) | 1 (11.1%) | 0 | |
| – Persistent tremor | 1 (5.9%) | 0 | 1 (12.5%) | |
| – Persistent tongue dystonia | 2 (11.8%) | 0 | 2 (25.0%) | |
| – Perioral tightness | 1 (5.9%) | 1 (11.1%) | 0 | |
| – Bradykinesia | 2 (11.8%) | 1 (11.1%) | 1 (12.5%) | |
| – Parkinsonism | 1 (5.9%) | 1 (11.1%) | 0 | |
| Gait impairment | 2 (11.8%) | 1 (11.1%) | 0 | |
| Surgical Site infection | 1 (5.9%) | 1 (11.1%) | 0 | |
| Dystonia subgroup | 11 | 4 | 7 | |
| – Pre-operative baseline BFMDRS score | 80.9 ± 20.0 | 78.1 ± 26.3 | 82.4 ± 17.6 | p value 0.75 |
| – BFMDRS score at 6 months post-surgery | 57.8 ± 22.8 | 58.3 ± 31.6 | 57.4 ± 19.1 | p value 0.95 |
| – Percentage reduction of BFDRS score at 6 m | 29.6 ± 16.6 | 26.9 ± 19.5 % | 31.6 ± 16.2 % | |
| – BFMDRS mean score difference at baseline and 6 m | p value < 0.001 | p value 0.11 | p value 0.001 | |
| – BFMDRS score at 12 months post-surgery | 60.9 ± 11.1 | 57.3 ± 11.2 (n = 3) | 62.7 ± 5.8 (n = 6) | p value 0.53 |
| – Percentage reduction of BFDRS score at 12 m compared to baseline | 22.3 ± 10.4 | 17.4 ± 3.1 % | 24.8 ± 12.1 % | |
| – BFMDRS mean score difference at baseline and 12 m | p value 0.02 | p value 0.06 | p value 0.010 | |
| – BFMDRS mean score difference between 6 m and 12 m | p value 0.28 | p value 0.13 | p value 0.92 |
[i] @-In one patient, the indication of surgery was tremor and dystonia.
BFMDRS: Burke-Fahn-Marsden-Dystonia-Rating scale, DBS-deep brain stimulation, GPi-globus pallidus interna, Lt-left, m-month, NA-not applicable, Rt-right, ViM-ventralis intermediate nucleus, y-years.
Figure 1
BMFDRS motor scores at baseline, 6-months and 12-months post operatively in patients with dystonia.
Video e1
Video of the patient-NBIA4. Segment-1: pre-operative video showing severe generalized dystonia with opisthotonus and Ryle’s tube in situ due to dysphagia. Segment-2: Video of the patient 6-months after bilateral GPi-DBS showing improvement in dystonia, opisthotonus and dysphagia. The video was taken after written informed consent for online publication and dissemination.
Video e2
Video of the patient-WD8. Segment-1: pre-operative video showing significant disabling rubral tremor in right upper limb with conducted tremor in left upper limb as well. Segment-2: 6-months after left ViM thalamotomy showing significant improvement of the tremor and the functional ability. The video was taken after written informed consent for online publication and dissemination.
Video e3
Video of the patient-DYT1. Segment-1: pre-operative video showing significant generalized dystonia. Segment-2: 3-months post bilateral GPi-DBS with significant improvement in generalized dystonia as well as gait. The video was taken after written informed consent for online publication and dissemination.
Table 2
Individual patient characteristics.
| ID | INDICATION | AAO (YRS) | AAP (YRS) | AAS (YRS) | DOI (YRS) | SEX | MEDICAL MANAGEMENT | SX TYPE | OUTCOME | COMPLICATIONS | STIMULATION PARAMETERS | MANAGEMENT IN FOLLOW UP | OUTCOME |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| WD1 | Dystonia | 8 | 8 | 11 | 3 | F | Penicillamine 1 gm THP 6 mg Zinc sulfate 220 mg Baclofen 20 mg | BL GPi Px | No improvement (BFMDRS scores 104, which remained unchanged at 6 months) | Expired from hepatic failure | NA | ----- | ----- |
| WD2 | Dystonia | 15.5 | 16 | 17 | 1.5 | M | Penicillamine 1 gm THP 18 mg Zinc sulfate 660 mg TBZ 100 mg CBZ 400 mg Baclofen 20 mg | BL GPi Px | Improvement of BFMDRS scores by 40.9% at 6 months and 13.9% at 12 months | Persistent disabling dystonia, blepharospasm, tongue dystonia | NA | Redo bilateral pallidotomy at 14 months post-surgery. Medical management with Penicillamine 1 gm, THP 18 mg, Zinc sulphate 660 mg, TBZ 75 mg, Baclofen 10 mg and CBZ 400 mg | Blepharospasm improved; Dystonia- not improved |
| WD3 | Dystonia | 11.5 | 12 | 15 | 3.5 | M | Penicillamine 1.25 gm THP 18 mg Zinc sulfate 220 mg Baclofen 20 mg Clonazepam 1 mg Levodopa 250 mg | BL GPi DBS | Improvement of BFMDRS scores by 16.6 % at 6 months and 12.5% at 12 months. | Persistent swallowing difficulty at 1 month. Perioral tightness | At 2 months C+1-/2.1 V/150 µS/180 Hz C+9/2.1 V/150 µS/180 Hz | Reprogramming Penicillamine 1.25 gm THP 18 mg Zinc sulfate 220 mg Baclofen 20 mg Clonazepam 1 mg Levodopa 250 mg | Perioral tightness improved. dystonia persisted of lesser severity |
| WD4 | Dystonia | 11 | 12 | 15 | 4 | M | Penicillamine 1 gm Zinc sulfate 660 mg THP 12 mg TBZ 75 mg Levodopa 300 mg Baclofen 20 mg Diazepam 7.5 mg | BL GPi DBS | Improvement of BFMDRS scores by 20% at 6 months and 10% at 12 months | Dystonic spasms | At 3 months C+2-/2 V/150 µS/180 Hz C+10/2 V/150 µS/180 Hz | At 1 year follow up, reprogramming to C+2-/3 V/150 µS/180 Hz C+10-11/2 V/150 µS/180 Hz Penicillamine 1 gm Zinc sulfate 660 mg THP 12 mg TBZ 75 mg Levodopa 300 mg Baclofen 15 mg Diazepam 5 mg | Improvement in frequency of dystonic spasms, dystonia persistent |
| WD5 | Tremor | 15 | 17 | 23 | 8 | M | Penicillamine 1.25 gm THP 18 mg Zinc sulfate 660 mg Baclofen 20 mg | BL ViM Tx | Tremor scores (FTMRS) improved by 87.5% at 5 years and 90.6% at last follow up (10 years) compared to baseline | Dysarthria, postural tremors, bradykinesia persisted. Worsening of tremors to baseline scores | NA | Bilateral redo thalamotomy after 6 months At 1 year follow up, Penicillamine 1 gm THP 12 mg Zinc sulfate 660 mg Baclofen 20 mg | Sustained improvement with mild dysarthria and tremors. Functionally independent |
| WD6 | Tremor | 11 | 8# | 28 | 17 | F | Zinc 1320 mg Penicillamine 250 mg Pimozide 250 mg | UL ViM Tx | Tremor scores (FTMRS) improved by 75.9% at 2 months | Mild gait ataxia | NA | At 2 years follow up, Amantadine 100 mg Zinc 660 mg Penicillamine 250 mg | Mild ataxia persisted. Tremors improved. |
| WD7 | Tremor | 27 | 30 | 30 | 3 | M | Penicillamine 750 mg Zinc sulfate 660 mg THP 6 mg TBZ 75 mg Pimozide 250 mg | UL ViM Tx | FTMRS improved by 82.2% at 5 years and 86.7% at 10 years and 84.4% at 16 years follow-up compared to baseline | Transient gait imbalance, post-operative transient pneumocephalus | NA | At 16 years follow up, Penicillamine 750 mg THP 12 mg Zinc sulphate 660 mg | Tremors improved satisfactorily. Mild dysarthria has persisted |
| WD8 | Tremor | 16 | 20 | 22 | 6 | F | Penicillamine 1 gm Zinc sulfate 660 mg | UL ViM Tx | FTMRS reduction by 94% at 1 year follow-up | No adverse events reported | NA | At 1 year follow up, Penicillamine 500 mg Zinc sulfate 660 mg Clonazepam 0.75 mg | Significant improvement in tremors |
| NBIA1 | Dystonia | 3.5 | 5 | 7 | 3.5 | F | TBZ 75 mg Baclofen 30 mg THP 18 mg | BL GPi Px | Improvement of BFMDRS scores by 25% at 6 months and 18.2% at 12 months | Abnormal tongue protrusions | NA | At 1 year follow up, TBZ 37.5 mg, THP 18 mg, Clonazepam 0.5 mg, Baclofen 30 mg and Haloperidol 5 mg and Inj Botulinum toxin therapy in the tongue | Improvement in severity of dystonia |
| NBIA2 | Tremor+ Dystonia | 13 | 30 | 30 | 17 | M | Baclofen 30 mg THP 18 mg | UL ViM Tx | Improvement of BFMDRS scores by 41.6% at 6 months and 20% at 12 months. FTMRS improvement by 77.8 % at 3 years follow-up. | Febrile illness due to chest infection. Worsening of dystonia after stopping haloperidol | NA | At 3 years follow up, Botox for lingual dystonia Baclofen 20 mg THP 12 mg | Required ICU care and tracheostomy. Dystonia persisted with significant disability. Tremors improved. |
| NBIA3 | Dystonia | 7 | 9 | 12 | 5 | M | Baclofen 60 mg Levodopa 400 mg TBZ 112.5 mg THP 12 mg Diazepam 10 mg | BL GPi DBS | Improvement of BFMDRS scores by 27.3% at 6 months and 20.5% at 12 months | Improvement in dystonia score | At 3 months C+1- /1.0 V/150 µsec/130 Hz C+9-/1.0 V/150 µsec/130 Hz | At 2 years follow up, reprogramming C+1-/2.0 V/150 µsec/130 Hz C+9-/1.0 V/150 µsec/130 Hz Baclofen 30 mg Levodopa 400 mg TBZ 75 mg THP 12 mg | Persistent dystonia of reduced severity |
| NBIA4 | Dystonia | 3 | 4 | 6 | 3 | F | THP 19.5 mg Clonazepam 0.75 mg Pimozide 4 mg TBZ 75 mg Baclofen 15 mg | BL GPi DBS | Improvement of BFMDRS scores by 30.4% at 6 months and 35.9% at 12 months | Surgical site infection of cranial and abdominal wound (MRSA). Persistence of morning and nocturnal dystonic spasms | At 3 months, C+1-/3 V/120 µS/160 Hz C+9-/3 V/120 µS/160 Hz | Removal of leads | Improvement of dystonia for next 2 years, re-implantation of DBS leads for worsened dystonia, later expired from chest infection |
| NBIA5 | Dystonia | 26 | 28 | 32 | 6 | M | Baclofen 20 mg TBZ 75 mg Clonazepam 1 mg Levodopa 300 mg | BL GPi DBS | Improvement of BFMDRS scores by 38.0% at 6 months and 32.1% at 12 months | Blepharospasm, Parkinsonism | At 3 months C+1-/2.5 V/210 µS/60 Hz C+5-/2.5 V/210 µS/60 Hz | At 2 years follow up, reprogramming to C+1-/3.5 V/210 µS//130 Hz C+5-/3.4 V/210 µS/130 Hz,, Inj. Botulinum Toxin and medical management with Baclofen 20 mg TBZ 75 mg Clonazepam 0.75 mg, Levodopa 300 mg | Blepharospasm improved, dystonia persistent of reduced severity |
| NPC | Dystonia | 11 | 14 | 20 | 9 | F | THP 12 mg Baclofen 40 mg TBZ 100 mg Clonazepam 1.5 mg | BL GPi DBS | Improvement of BFMDRS scores by 21.1% at 6 months and 37.6% at 12 months | Dystonia persistent, speech abnormality, swallowing difficulty | At 3 months, C+1-/1.5 V/90 µS/180 Hz C+9-/1.5 V/90 µS/180 Hz | At 2 years follow up, reprogramming to C+1-/3.5 V/120 µS/180 Hz C+9-/3.5 V/120 µS/180 Hz THP 12 mg Baclofen 40 mg TBZ 50 mg Clonazepam 1.5 mg | Dystonia severity reduced but persistent |
| DYT | Dystonia | 9 | 11 | 13 | 4 | M | THP 12 mg TBZ 75 mg Levodopa 400 mg | BL GPi DBS | Improvement of BFMDRS scores by 64.1% at 6 months | Persistence of dystonia | At 3 months C+1-/1.3 V/150 µS/150 Hz C+9-/1.3 V/150 µS/150 Hz | At 9 months follow up, THP 12 mg TBZ, Levodopa tapered and stopped | Improvement in severity of dystonia |
| NAC | Chorea | 37 | 38 | 41 | 4 | M | TBZ 125 mg CBZ 600 mg Clonazepam 0.5 mg Baclofen 20 mg | BL GPi DBS | Improvement in UHDRS scores by 9.1 % at 6 months and 20% at 12 months | Head nodding and persistent choreiform movements | At 3 months C+2-/2.4 V/150 µS/180 Hz C+10-/1.9 V/150 µS/180 Hz | At 4 years follow up, reprogramming to C+2-/2.7 V/90 µS/130 Hz C+10-/2.2 V/90 µS/130 Hz TBZ 50 mg, CBZ 600 mg, Clonazepam 0.75 mg and Baclofen 20 mg | Improvement of head nodding movements but persistence of choreiform movements and dysarthria |
| TS | Complex motor tics | 10 | 11 | 15 | 5 | M | Haloperidol 15 mg Risperidone 6 mg Aripiprazole 20 mg Clonidine 0.4 mg Clonazepam 4 mg Valproate 800 mg Fluoxetine 20 mg Tetrabenazine 25 mg rTMS | BL GPi DBS | Improvement in tic severity scores (YGTSS scores) by 72% | Slight worsening of motor and vocal tics (YGTSS 30/100) at 1 year with psychiatric manifestations like defiant and demanding behaviours | C+1-/3.5 V/60 µS/130 Hz C+9-/3.5 V/60 µS/130 Hz C+1-/3.5 V/60 µS/130 Hz | At 3 years follow up, Amisulpiride 300 mg and Clonazepam 1 mg and behavioural therapy | Mild improvement in behavioural symptoms |
[i] # Patient presented at 8 years of age when she only had hepatic manifestations without neurological involvement.
AAO: age at onset, AAP: age at presentation, AAS: age at surgery, BFMDRS: Burke-Fahn-Marsden dystonia rating scale, BL: bilateral, CBZ: carbamazepine, DBS: deep brain stimulation, DOI: duration of illness before surgery, DYT: DYT-TOR1A, F: female, FTMRS: Fahn-Tolosa-Marin tremor rating scale, gm: gram, GPi: globus pallidus interna, M: male, mg: milligram, NA: Not applicable, NAC: Neuroacanthocytosis, NBIA: Neurodegeneration with brain iron accumulation, NPC: Niemann-Pick disease type-C, Px: pallidotomy, rTMS: repetitive Transcranial magnetic stimulation, Sx: surgery, TBZ: tetrabenazine, THP: trihexyphenidyl, TS: Tourette syndrome, Tx: thalamotomy, UL: unilateral, UHDRS: Unified Huntington disease rating scale, WD: Wilson’s disease, YGTSS: Yale global tic severity scale.
Figure 2
Outcome in patients with dystonia. A-Outcome after all surgical interventions combined, B-Outcome of DBS, C-Outcome after lesional surgery, D-Comparison of outcomes between DBS and lesional surgeries.
Table 3
Literature review on surgical management of RMDs.
| STUDY | STUDY DESIGN | SAMPLE SIZE | STUDY SUBJECT(S) | SURGERY | OUTCOMES | ADVERSE EVENT PROFILE |
|---|---|---|---|---|---|---|
| Wilson’s disease | ||||||
| Starikov et al. 2000 [20] | Case series | 27 | 16 patients with tremor form, 8 patients with tremor-rigidity form and a single patient with extrapyramidal-cortical form | Stereotaxic surgery of ViM and subthalamus | Significant decrement in hyperkinesia was reported in 17 patients | 5 deaths of which 2 had bleeding in the treatment zones, 1 brainstem bleed and extension of destruction into the internal capsule and hypothalamus |
| Sidiropoulos et al. 2013 [21] | Case report | 1 | Patient of Wilson’s disease with moderate to severe dystonic symptoms | Bilateral GPi DBS | At 20 weeks of stimulation, positive impact on caregiver’s burden, especially in regard to hand dexterity, and gait | No adverse events were reported |
| Low et al. 2019 [22] | Case report | 1 | Patient of Wilson’s disease with tremors and left sided choreo-athetosis. Tremors were dominant | Posterior subthalamic DBS | In view of dominant tremor and marked atrophy of lentiform nuclei, posterior subthalamic area was chosen. Early tremor suppression was achieved. Dystonia responded after 1 year | No adverse events were reported |
| Neurodegeneration with brain iron accumulation | ||||||
| Umemura et al.2004 [25] | Case report | 1 | 36-year-old patient of proven PKAN with generalized dystonia for 28 years | Bilateral GPi DBS | Improvement in motor score from 112 to 22.5 out of 120 with sustained benefit at 1 year follow-up | No adverse events were reported |
| Castelnau et al. 2005 [23] | Case series | 6 | Patients with genetically confirmed PKAN | Bilateral GPi DBS | Improvement in painful dystonic spasms and motor scores. Less significant improvement in BFMDRS disability scores. DBS of the subthalamic nucleus was less beneficial in 3 patients with PKAN compared to the pallidal or thalamic stimulation | No adverse events were reported |
| Krause et al. 2006 [19] | Case report | 1 | 13-year-old genetically proven patient of PKAN, intractable dystonia for 7 years | Bilateral GPi DBS | Improvement in motor scores by 70 % in 1 year. Over the next 5 years, there was gradual deterioration, but there was still functionally meaningful benefit | Fixed posturing and bradykinesia worsened |
| Shields et al. 2007 [26] | Case report | 1 | 18-year-old with genetically proven patient of PKAN with dystonia for 9 years | Bilateral GPi DBS | Improvement in motor scores on BFMDRS – 86 to 66 out of 120. Patient was able to ambulate post-surgery | No adverse events reported |
| Mikati et al. 2008 [28] | Case report | 1 | 11-year-old girl with early onset genetically proven PKAN | Bilateral GPi DBS | Marked improvement in motor and functional scores*. Device infection at 3 months led to its removal, following which her motor symptoms and functionality worsened. | Patient returned to pre-surgical state in 4 months |
| Sathe et al. 2013 [24] | Case report | 1 | 10-year-old girl with PKAN with severe generalized dystonia, with blepharospasm and in a wheel-chair bound state | Bilateral GPi DBS | Sustained improvement in BFMDRS score for 120/120 to 42.5/120 post-operatively at 15 months follow up | No improvement in speech |
| Choreacanthocytosis | ||||||
| Shin et a. 2011 [30] | Case report | 1 | 39-year-old lady of genetically proven ChAc with refractory hyperkinetic movement and truncal bending spasm for 4 years duration | Bilateral GPi DBS | Improvement in symptoms which sustained at 13 months | No adverse events reported |
| Li et al. 2012 [31] | Case report | 2 | 2 patients (39 and 30-years of age) with genetically proven ChAc of 22 and 12-years duration respectively | Bilateral GPi DBS | Chorea improved markedly 4 weeks post-stimulation. Dystonia showed only mild improvement | No adverse events reported |
| Ruiz et al. 2009 [32] | Case report | 1 | 35-year-old of proven ChAc with oromandibular dystonia, dysarthria with chorea | Bilateral GPi DBS | Improvement in chorea and dystonia | Worsening of truncal spasms |
| Wihl et al. 2001 [34] | Case report | 1 | 38-year-old male of proven ChAc with chorea, oromandibular dyskinesia and falls | Bilateral GPi DBS | No benefits on low or high frequency stimulation | No adverse events reported |
| Burbaud et al. 2002 [33] | Case report | 1 | 35-year, lady of proven ChAc with chorea, oromandibular dyskinesia, truncal spasm | Bilateral GPi DBS | Improvement in choreic movements on high frequency stimulation (130 Hz) | No adverse events reported |
| Rare inherited dystonia | ||||||
| Beaulieu-Boire et al. 2016 [17] | Prospective | 11 patients with genetically proven RMD with disabling dystonia | Patients with genetically proven RMDs of 1 case each of ataxia-telangiectasia, chorea-acanthocytosis, dopa- responsive dystonia, congenital nemalinemyopathy, methylmalonic aciduria, neuronal ceroid lipofuscinosis, spinocerebellar ataxia types 2 and 3, Wilson’s disease, Woodhouse–Sakati syndrome, methylmalonic aciduria, and X trisomy | Bilateral GPi DBS $ | DBS effects on dystonia se verity were marginally effective, with a mean improvement of 7.9% (p = 0.39) at 1-year follow-up and 16.7% (p = 0.46) at last follow-up (mean 47.3 ± 19.9 months after surgery). | Device- related infection occurred in 1 patient (X trisomy). Two patients required a second procedure: the patient with SCA 2 received bilateral STN DBS due to lack of benefit from GPi DBS, with no further improvement, and the patient with SCA 3 had repositioning of the electrodes within the GPi, with mild benefit. Deterioration of speech was reported by 2 patients. |
| Primary dystonia | ||||||
| Kupsch et al. 2006 [45] | Randomized, double-blind, sham- controlled trial | 40 patients of primary generalized or segmental dystonia | 40 to 75 years with disease duration of atleast 5 years, with marked disability despite optimal medical management | Bilateral GPi DBS | Improvement in mean movement score (p < 0.001). All movement symptoms showed significant improvement except speech and swallowing | Dysarthria was the most common. 22 adverse events in 19 patients. |
| Vidailhet et al. 2005 [39] | Prospective, controlled, multi-centre | 22 patients with primary generalized dystonia | Primary generalized dystonia with a combination of segmental crural dystonia (involving one leg and the trunk) and the involvement of any other segment (the cranium, neck, or upper or lower limbs); no secondary cause, with normal neurological examination (except dystonia), MMSE score of at least 24 and normal MRI. | Bilateral GPi DBS | Significant improvement in mean motor (p < 0.001) and disability scores at 12 months (p < 0.001) | 5 transient adverse events in 3 patients |
| Eltahawy et al. 2003 [40] | Prospective study | 15 patients with primary dystonia | 9 patients with primary dystonia and 6 patients with secondary dystonia (2 post encephalitis cases and 1 case each of post stroke, Huntington disease, Tardive dyskinesia and Glutaric aciduria) | Bilateral GPi DBS except for 3 cases @ | Primary dystonia responded better to GPi procedures (DBS and lesioning). No difference in response between pallidotomy and DBS | 2/15 patients, both treated with bilateral pallidotomy, developed persistent speech impairment: hypophonia (n = 1) or dysphonia (n = 1). |
| Volkman et al. 2012 [44] | Randomised control trial | 40 patients with primary dystonia | 40 patients with severe generalised or segmental idiopathic dystonia | Bilateral GPi DBS | Significant improvements in dystonia severity at 3-years and 5-years compared with baseline were reported | Dysarthria and transient worsening of dystonia were the most common non-serious adverse events. 16/21 serious adverse events were device related. |
[i] $ One case underwent ViM Thalamotomy.
# Study by Eltahawy et al. had 6 cases of secondary dystonia
@ 2 unilateral lesional surgeries were done in 1 case each of post-encephalitis and post-stroke. 1 case of post-encephalitis dystonia underwent unilateral DBS
* Barry-Albright dystonia scale, functional independence measures in children (WeeFIM) were used
ChAc-chorea-acanthocytosis, DBS-deep brain stimulation, GPi-globus pallidus interna, MMSE-mini-mental status examination, MRI-magnetic resonance imaging, PKAN-pantothenate kinase-associated neurodegeneration, RMD-rare movement disorders, SCA-spinocerebellar ataxia, STN-subthalamic nucleus, ViM-ventrolateral intermedius nucleus of thalamus.
| BFMDRS | Burke-Fahn-Marsden-Dystonia-Rating Scale |
| DBS | Deep brain stimulation |
| ERN | European Reference Network |
| FTM | Fahn-Tolosa-Marin |
| GPi | Globus pallidus interna |
| HARS | Hamilton anxiety rating scale |
| HDRS | Hamilton depression rating scale |
| MRI | Magnetic resonance imaging |
| NBIA | Neurodegeneration with brain iron accumulation |
| NPC | Niemann-Pick type C |
| PKAN | Pantothenate kinase-associated neurode-generation |
| RD | Rare disease |
| RMDs | Rare movement disorders |
| RND | Rare neurologic disease |
| rTMS | Repetitive transcranial magnetic stimulation |
| S.D. | Standard deviation |
| UHDRS | Unified Huntington Disease Rating Scale |
| ViM | Ventralis intermediate nucleus |
| WD | Wilson’s disease |
| YBOCSS | Yale-Brown obsessive compulsive severity scale |
| YGTSS | Yale Global Tic Severity Scale |