Outcomes of Unilateral Pallidotomy in Focal and Hemidystonia Cases: A Single-Blind Cohort Study

BACKGROUND

The role of deep brain stimulation in the treatment of dystonia has been widely documented. However, there is limited literature on the outcome of lesioning surgery in unilateral dystonia.

OBJECTIVE

We restrospectively reviewed our cases of focal and hemidystonia undergoing unilateral Pallidotomy at our institute to evaluate the short-term and long-term outcome.

METHODS

Patients who underwent radiofrequency lesioning of GPi for unilateral dystonia between 1999 and 2019 were retrospectively reviewed. All patients were evaluated using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) and Dystonia Disability Scale (DDS) preoperatively at the short term follow-up (<1 year) and at long-term follow-up (2-7.5 years). Video recordings performed at these time points were independently reviewed by a blinded movement disorders specialist.

RESULTS

Eleven patients were included for analysis. The preoperative, short-term, and long-term follow-up motor BFMDRS and DDS scores were 15.5 (IQR [interquartile range]: 10.5, 23.75) and 10.5 (IQR: 6.0, 14.5); 3.0 (IQR: 1.0, 6.0, P = 0.02) and 3.0 (IQR: 3.0, 8.0, P = 0.016); and 14.25 (IQR: 4.0, 20.0, P = 0.20) and 10.5 (IQR: 2.0, 15.0, P = 0.71) respectively. For observers B, the BFMDRS scores at the same time points were 19 (IQR: 12.5, 27.0), 7.5 (IQR: 6.0, 15.0, P = 0.002), and 21 (IQR: 7.0, 22.0, P = 0.65) respectively. The improvement was statistically significant for all observations at short-term follow-up but not at long-term follow-up.

CONCLUSION

Pallidotomy is effective for hemidystonia or focal dystonia in the short term. Continued benefit was seen in the longer term in some patients, whereas others worsened. Larger studies may be able to explain this in future.

Neurosurgical management of non-spastic movement disorders

BACKGROUND

Non-spastic movement disorders in children are common, although true epidemiologic data is difficult to ascertain. Children are more likely than adults to have hyperkinetic movement disorders defined as tics, dystonia, chorea/athetosis, or tremor. These conditions manifest from acquired or heredodegenerative etiologies and often severely limit function despite medical and surgical management paradigms. Neurosurgical management for these conditions is highlighted.

METHODS

We performed a focused review of the literature by searching PubMed on 16 May 2023 using key terms related to our review. No temporal filter was applied, but only English articles were considered. We searched for the terms (("Pallidotomy"[Mesh]) OR "Rhizotomy"[Mesh]) OR "Deep Brain Stimulation"[Mesh], dystonia, children, adolescent, pediatric, globus pallidus, in combination. All articles were reviewed for inclusion in the final reference list.

RESULTS

Our search terms returned 37 articles from 2004 to 2023. Articles covering deep brain stimulation were the most common (n = 34) followed by pallidotomy (n = 3); there were no articles on rhizotomy.

DISCUSSION

Non-spastic movement disorders are common in children and difficult to treat. Most of these patients are referred to neurosurgery for the management of dystonia, with modern neurosurgical management including pallidotomy, rhizotomy, and deep brain stimulation. Historically, pallidotomy has been effective and may still be preferred in subpopulations presenting either in status dystonicus or with high risk for hardware complications. Superiority of DBS over pallidotomy for secondary dystonia has not been determined. Rhizotomy is an underutilized surgical tool and more study characterizing efficacy and risk profile is indicated.

Neurosurgical management of elevated tone in childhood: interventions, indications and uncertainties

Elevated tone (hypertonia) is a common problem in children with physical disabilities. Medications intended to reduce tone often have limited efficacy, with use further limited by a significant side effect profile. Consequently, there has been growing interest in the application of Neurosurgical Interventions for the Management of Posture and Tone (NIMPTs). Three main procedures are now commonly used: selective dorsal rhizotomy (SDR), intrathecal baclofen (ITB) and deep brain stimulation (DBS). This review compares these interventions, along with discussion on the potential role of lesioning surgery. These interventions variably target spasticity and dystonia, acting at different points in the distributed motor network. SDR, an intervention for reducing spasticity, is most widely used in carefully selected ambulant children with cerebral palsy. ITB is more commonly used for children with more severe disability, typically non-ambulant, and can improve both dystonia and spasticity. DBS is an intervention which may improve dystonia. In children with certain forms of genetic dystonia DBS may dramatically improve dystonia. For other causes of dystonia, and in particular dystonia due to acquired brain injury, improvements following surgery are more modest and variable. These three interventions vary in terms of their side-effect profile and reversibility. There are currently populations of children for who it is unclear which intervention should be considered (SDR vs ITB, or ITB vs DBS). Concerns have been raised as to the equity of access to NIMPTs for children across the UK, and whether the number of surgeries performed each year meets the clinical need.

[Efficacy of CT-guided partial radiofrequency ablation of bilateral responsible cranial nerves in the treatment of Meige syndrome]

Objective: To evaluate the efficacy of CT-guided partial radiofrequency ablation of bilateral responsible cranial nerves in the treatment of Meige syndrome. Methods: The Clinical data of 56 patients with Meige syndrome in the Department of Pain Medicine, Affiliated Hospital of Jiaxing University from June 2019 to January 2023 were retrospectively analyzed [19 males and 37 females, aged 42-76 (58.6±8.3) years], including 51 cases of blepharospasm, 3 cases of oromandibular dystonia and 2 cases of blepharospasm concomitant with oromandibular dystonia. CT-guided partial radiofrequency ablation of bilateral responsible cranial nerves was performed on different types of Meige syndrome. And the efficacy and complications of the technique were observed. Results: Fifty-one patients with blepharospasm Meige syndrome underwent CT-guided radiofrequency of facial nerve through bilateral stylomastoid foramen punctures, the symptoms of blepharospasm disappeared completely, leaving bilateral mild and moderate facial paralysis symptoms. Three patients with oral-mandibular dystonia underwent CT-guided radiofrequency therapy by bilateral foramen ovale puncture of mandibular branches of trigeminal nerve, masticatory muscle spasm disappeared, the patients had no difficulty opening the mouth, and the skin numbness in bilateral mandibular nerve innervation area was left. Two cases of Meige syndrome with blepharospasm concomitant with oromandibular dystonia were treated by radiofrequency of facial nerve and mandibular branch of trigeminal nerve, and all symptoms disappeared. The patients were followed up for 1-44 months after the operation, and the symptoms of mild and moderate facial paralysis disappeared at (3.2±0.8) months after the operation, but the numbness did not disappear. Three patients with blepharospasm recurred at the 14, 18 and 22 months after the operation, respectively, while the rest cases did not recur. Conclusions: According to different types of Meige syndrome, CT-guided partial radiofrequency ablation of responsible cranial nerves can effectively treat the corresponding type of Meige syndrome. The complications are only mild and moderate facial paralysis which can be recovered, and/or skin numbness in the mandibular region.

[Methods and results of neurosurgical treatment of cerebral palsy]

Treatment of spastic syndrome and muscular dystonia in patients with cerebral palsy is a complex clinical problem. Effectiveness of conservative treatment is not high enough. Modern neurosurgical techniques for spastic syndrome and dystonia are divided into destructive interventions and surgical neuromodulation. Their effectiveness is different and depends on the form of disease, severity of motor disorders and age of patients.

OBJECTIVE

To evaluate the effectiveness of various methods of neurosurgical treatment of spasticity and muscular dystonia in patients with cerebral palsy.

MATERIAL AND METHODS

We To evaluate the effectiveness of various methods of neurosurgical treatment of spasticity and muscular dystonia in patients with cerebral palsy.analyzed literature data in the PubMed database using the keywords «cerebral palsy», «spasticity», «dystonia», «selective dorsal rhizotomy», «selective neurotomy», «intrathecal baclofen therapy», «spinal cord stimulation», «deep brain stimulation».

RESULTS

Effectiveness of neurosurgery was higher for spastic forms of cerebral palsy compared to secondary muscular dystonia. Destructive procedures were the most effective among neurosurgical operations for spastic forms. Effectiveness of chronic intrathecal baclofen therapy decreases in follow-up due to secondary drug resistance. Destructive stereotaxic interventions and deep brain stimulation are used for secondary muscular dystonia. Effectiveness of these procedures is low.

CONCLUSION

Neurosurgical methods can partially reduce severity of motor disorders and expand the possibilities of rehabilitation in patients with cerebral palsy.

Combined Unilateral Radiofrequency Lesioning of the Motor Thalamus, Field of Forel, and Zona Incerta: A Series of Cases With Dystonia

BACKGROUND

Dystonia is a group of disorders characterized by involuntary slow repetitive twisting movements and/or abnormal posture. Surgical options such as neuromodulation through deep brain stimulation and neuroablative procedures are available for patients who do not respond to conservative treatment.

OBJECTIVE

To present our series of patients with dystonia who were treated with stereotactic combined unilateral radiofrequency lesioning of the motor thalamus, field of Forel, and zona incerta.

METHODS

Medical records of 50 patients with dystonia who were treated with unilateral combined lesions were reviewed. Outcomes of the surgical procedure were evaluated using the Burke-Fahn-Marsden Dystonia Rating Scale (with movement and disability subscales) and Unified Parkinson's Disease Rating Scale-tremor items.

RESULTS

Based on the symptoms, patients were categorized as having generalized dystonia (34%), hemidystonia (30%), and dystonic tremor (DT) (36%). Primary/idiopathic dystonia, primary genetic/hereditary dystonia, and secondary dystonia accounted for 16%, 4%, and 80% of patients, respectively. The mean follow-up duration was 156.2 ± 88.9 mo. The overall improvement in the Burke-Fahn-Marsden Dystonia Rating Scale scores (movement and disability, respectively) was 57.8% and 36.4% in generalized dystonia, 60.0% and 45.8% in hemidystonia, and 65.6% and 56.8% in DT. Patients with DT showed an 83.3% improvement in mean Unified Parkinson's Disease Rating Scale tremor score. Patients with cerebral palsy showed mean improvements of 66.7% in movement scores and 50.8% in disability scores. No mortality or major morbidity was observed postoperatively.

CONCLUSION

Stereotactic radiofrequency unilateral combined thalamotomy, campotomy, and zona incerta lesions may be an effective surgical alternative for patients with dystonia, especially those with secondary dystonia resistant to deep brain stimulation.

The minimal clinically important change in the motor section of the Burke-Fahn-Marsden Dystonia Rating Scale for generalized dystonia: Results from deep brain stimulation

BACKGROUND

The minimal clinically important difference (MCID) describes the smallest change in an outcome that is considered clinically meaningful. The Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) is the most frequently rating scale assessing the efficacy of deep brain stimulation therapy (DBS) for dystonia. To expand our understanding, we evaluated the MCID thresholds for the BFMDRS motor subscale (MS) using physician-reported outcomes.

METHODS

We assessed the MCID thresholds for the BFMDRS using movement disorder specialist ratings of videotapes from patients with genetically determined dystonia (Tor1A and THAP1) who underwent bilateral globus pallidum internum (GPi) DBS. We calculated the effect size of the BFMDRS-MS change and determined the MCID thresholds using the Clinical Global Impression of Change (CGIC).

RESULTS

Twelve participants with a median age at DBS of 44.5 (range:27-68) had baseline and follow-up BFMDRS-MS with a median post-DBS follow-up of 5.5 years. Based on descriptive analysis, patients with good improvement after DBS according to the CGIC [8/12 (67%)] had a median BFMDRS-MS score reduction of 77% [Interquartile range (IQR):66.2;91.0) with an effect size of 0.39, and those with non-improvement [4/12 (33%)], had a median BFMDRS-MS score reduction of 62% (IQR:36.6;83.6).

CONCLUSIONS

Our MCID estimates can be utilized in clinical practice in judging clinical relevance. However, further larger, powered studies are needed to simultaneously determine and compare MCID using patient and physician-reported outcomes in segmental and generalized dystonia in genetic and non-genetic populations.

Comorbid seizure reduction after pallidothalamic tractotomy for movement disorders: Revival of Jinnai's Forel-H-tomy

Forel-H-tomy for intractable epilepsy was introduced by Dennosuke Jinnai in the 1960s. Recently, Forel-H-tomy was renamed to "pallidothalamic tractotomy" and revived for the treatment of Parkinson's disease and dystonia. Two of our patients with movement disorders and comorbid epilepsy experienced significant seizure reduction after pallidothalamic tractotomy, demonstrating the efficacy of this method. The first was a 29-year-old woman who had temporal lobe epilepsy with focal impaired awareness seizure once every three months and an aura 10-20 times daily, even with four antiseizure medicines. For the treatment of hand dyskinesia, she underwent left pallidothalamic tractotomy and her right-hand dyskinesia significantly improved. Fourteen months later, she had experienced no focal impaired awareness seizure and the aura decreased to one to three times per month. The second case was that of a 15-year-old boy diagnosed with progressive myoclonic epilepsy, who developed generalized tonic-clonic seizure, which manifested once every month, despite treatment with five antiseizure medicines. After surgery, myoclonic movements in his right hand slightly improved. A one-year follow-up revealed that he had not experienced a generalized tonic-clonic seizure. The lesion locations in the two cases were close to the vicinity of Jinnai's Forel-H-tomy. Forel's field H deserves reconsideration as a treatment target for intractable epilepsy.

Surgical Tone Reduction in Cerebral Palsy

This article overviews the surgical options for hypertonia management in cerebral palsy, both spasticity and dystonia. We review the history and use of intrathecal baclofen. We contrast its use with the indications for selective dorsal rhizotomy and review how it is the optimal technique to lower tone in the ambulatory spastic diplegic patient with cerebral palsy. This article reviews the advent of deep brain stimulation, with an emphasis on selection criteria and expected outcomes in this population. The article reviews the principles and use of selective peripheral neurotomy as it is applied to focal spasticity not requiring systemic tone reduction.

[Neurosurgical treatment of dystonia]

In this review, we present evidence of treatment effect with deep brain stimulation (DBS) in patients with isolated forms of dystonia with generalised-, segmental- and focal phenotypes as well as tardive dystonia and dyskinetic cerebral palsy. Dystonia is a heterogeneous movement disorder, which can be disabling and difficult to treat. Patients with dystonia, who do not experience relief with medication and botulinum toxin, may be candidates for DBS.

Update on treatments for dystonia

Oral medication, botulinum toxin injections, and deep brain stimulation are the current mainstays of treatment for dystonia. In addition, physical and other supportive therapies may help prevent further complications (eg, contractures) and improve function. This review discusses evidence-based medical treatment of dystonia with an emphasis on recent advances in treatment. We will also review the current treatment approaches and suggest ways in which these therapies can be applied to individuals with dystonia.

Dystonia

INTRODUCTION

Dystonia is usually a lifelong condition with persistent pain and disability. Focal dystonia affects a single part of the body; generalised dystonia can affect most or all of the body. It is more common in women, and some types of dystonia are more common in people of Ashkenazi descent.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments, surgical treatments, and physical treatments for focal and generalised dystonia? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2013 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 19 studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review, we present information relating to the effectiveness and safety of the following interventions: acupuncture, amantadine, baclofen, benzatropine, biofeedback, botulinum toxins, bromocriptine, carbamazepine, carbidopa/levodopa, clonazepam, clozapine, deep brain stimulation of thalamus and globus pallidus, diazepam, gabapentin, haloperidol, lorazepam, myectomy (for focal dystonia), occupational therapy, ondansetron, physiotherapy, pregabalin, procyclidine, selective peripheral denervation (for focal dystonia), speech therapy, tizanidine, trazodone hydrochloride, and trihexyphenidyl.

Functional neurosurgery for secondary dystonia: indications and long-term results

Dystonia is a movement disorder characterized by patterned, repetitive, phasic, or tonic sustained muscle contractions that produce abnormal, often twisting, postures or repetitive movements. When the disorder is genetic or the cause is unknown and dystonia is the sole feature, the disease is called primary or idiopathic, conversely secondary dystonia (SD) may be caused by various brain insults. Both primary dystonia and SD have been notorious for their poor response to medical treatment. Today, stereotactic neurosurgical procedures are offered to improve the disability and quality of life of patients who do not respond to medical therapy. However, SD shows less and more variable results than primary dystonia to neurosurgical procedures, the benefits of ablative or deep brain stimulation (DBS) procedures in basal structures being still subject to debate and much harder to fully appreciate. In this work, the authors show a 33-patient series with secondary dystonia, separating the statistic and clinical analysis into several etiology groups: perinatal insults, tardive syndromes, genetic syndromes, and posttraumatic. In these groups, we show the mean BFM score improvement in the different patient series, comparing our results with world literature, and finally propose a classification system for bettering the clinical approach in surgery decision when this is indicated.

[Update on multimodal neurosurgical management of dystonias]

The neurosurgical treatment of dystonia has progressed markedly since the introduction of deep brain stimulation of the globus pallidum interna. However, dystonia is not a single disorder but comprises various types and causes, and it is true that deep brain stimulation cannot cover the complex nature of dystonia. Depending on the distribution of symptoms and causes, we have to consider other surgical managements such as thalamotomy, peripheral denervation, and intrathecal baclofen. Such a multi-modal strategy has enabled us to treat and even cure many patients with dystonias. No treatment other than various neurosurgical approaches yields better results in the management of dystonias. In this sense, we are now at a stage where we should regard dystonia as a neurosurgical disorder in terms of treatment.

What happened to posteroventral pallidotomy for Parkinson's disease and dystonia?

Fifteen years after its resurrection, pallidotomy for Parkinson's disease (PD) and dystonia has once again been supplanted, this time by deep brain stimulation (DBS). Did this occur because pallidotomy was not effective or safe, or because DBS was found to be more effective and safer? This review focuses on the evidence-and its quality-supporting the effectiveness and safety of pallidotomy for PD and dystonia, and the comparative effectiveness and safety of DBS of the subthalamic nucleus (STN) and globus pallidus pars interna (GPi). Discussed first are the determinants of "level 1" recommendations, including the confounding effects on interpretation of randomized clinical trials (RCTs) that fail to control for patient bias (i.e., placebo effects). Although several RCTs have been performed comparing unilateral pallidotomy to medical therapy, GPi DBS, or STN DBS for PD, none controlled for patient bias. Comparison of these trials to estimate the placebo effect, and examination of retrospective case series, suggests that the true effectiveness of unilateral pallidotomy is 20% to 30% reduction of 'off' total motor UPDRS scores, which is similar to the effects of unilateral GPi DBS or STN DBS, but less than bilateral STN DBS. At experienced centers, safety of unilateral pallidotomy appears equivalent to unilateral DBS, but bilateral DBS is likely safer than bilateral pallidotomy. Whereas there have been no RCTs of pallidotomy for dystonia, two double-blind, sham-controlled RCTs of bilateral GPi DBS were performed. Nevertheless, limited uncontrolled series suggest that bilateral pallidotomy is similar to GPi DBS in effectiveness and safety for dystonia. Thus, pallidotomy was not rejected because of lack of effectiveness or safety, and it remains a viable alternative in situations where DBS is not available or not feasible.

Chronic bilateral pallidal stimulation in a patient with DYT-1 positive primary generalized dystonia. A long-term follow-up study

Primary generalized dystonia is a medically refractory progressive disease of the brain causing near total functional handicap of affected patients. The authors present the effectiveness of bilateral globus pallidus internus (GPi) stimulation in one patient with primary DYT-1 positive dystonia. Pharmacotherapy completely failed to control generalized dystonic movements. The patient was referred for surgical treatment and underwent bilateral implantation of DBS leads in the GPi. The formal objective assessment included the Burke-Fahn-Marsden dystonia rating scale (BFMDRS). Clinical and functional BFMDRS assessments were performed before and after surgery till 5 years postoperatively. All stimulation-induced side effects were reversible. Chronic bilateral pallidal stimulation is an effective and safe treatment in patients with primary generalized DYT-1 positive dystonia. The effectiveness of pallidal stimulation was proved by the objective validated BFMDRS assessment at 5 years follow-up examination.

Intracerebral Microvascular Measurements during Deep Brain Stimulation Implantation using Laser Doppler Perfusion Monitoring

The aim of the study was to investigate if laser Doppler perfusion monitoring (LDPM) can be used in order to differentiate between gray and white matter and to what extent microvascular perfusion can be recorded in the deep brain structures during stereotactic neurosurgery. An optical probe constructed to fit in the Leksell Stereotactic System was used for measurements along the trajectory and in the targets (globus pallidus internus, subthalamic nucleus, zona incerta, thalamus) during the implantation of deep brain stimulation leads (n = 22). The total backscattered light intensity (TLI) reflecting the grayness of the tissue, and the microvascular perfusion were captured at 128 sites. Heartbeat-synchronized pulsations were found at all perfusion recordings. In 6 sites the perfusion was more than 6 times higher than the closest neighbor indicating a possible small vessel structure. TLI was significantly higher (p < 0.005) and the perfusion significantly lower (p < 0.005) in positions identified as white matter in the respective MRI batch. The measurements imply that LDPM has the potential to be used as an intracerebral guidance tool.

Surgery for other movement disorders: dystonia, tics

PURPOSE OF REVIEW

Various movement disorders are now treated with stereotactic procedures, particularly deep brain stimulation. We review the neurosurgical treatment of dystonias and tics, focusing mainly on the surgical aspects and outcome of deep brain stimulation.

RECENT FINDINGS

Pallidal stimulation is nowadays the mainstay surgical treatment for patients with dystonia, particularly generalized dystonia. Various well designed recent clinical trials support the efficacy of the procedure. Improvements of 40-80% have been reported in primary generalized, segmental and cervical dystonia. For secondary dystonia, a similar outcome has been described in patients with tardive dystonia and pantothenate kinase-associated neurodegeneration. In patients with Tourette's syndrome, the results of the first trials with thalamic and pallidal deep brain stimulation have been very promising. Improvements of 70-90% in the frequency of tics have been reported with surgery in both targets.

SUMMARY

Deep brain stimulation has become an established therapy for dystonia and is currently being used to treat Tourette's syndrome. With accumulation of experience, clinical features that are more responsive to surgery and the best surgical candidates will be revealed. This will likely improve even further the outcome of surgery for the treatment of these disorders.

Thirty days complication rate following surgery performed for deep‐brain‐stimulation

Serious adverse events (SAEs) during the first 30 postoperative days after stereotactic surgery for Deep-Brain-Stimulation performed in 1,183 patients were retrospectively collected from five German stereotactic centers. The mortality rate was 0.4% and causes for death were pneumonia, pulmonary embolism, hepatopathy, and a case of complicated multiple sclerosis. The permanent surgical morbidity rate was 1%. The most frequently observed SAEs were intracranial hemorrhage (2.2%) and pneumonia (0.6%). Skin infection occurred in 5 of 1,183 patients (0.4%). Surgical complications caused secondary AEs (e.g. pneumonia) preferentially in older patients and in patients treated for Parkinson's disease (PD). Complication rates did not differ among the five centers.

Unilateral pallidotomy for hemidystonia

Hemidystonia is a clinical presentation of many pathological conditions that can affect the basal ganglia. It is usually a refractory condition to current medical treatment. Recently, stereotactic procedures such as radiofrequency lesioning or deep brain stimulation provided hope for patients with dystonia; we are reporting the clinical outcome of a patient with hemidystonia treated with unilateral pallidotomy. A 15-year-old boy with no family history of movement disorders and normal perinatal history is presented. He started to have progressive dystonic contractions in the right hand and extended to involve both the upper and lower extremities in the right side over a period of 3 years. He was subjected to a left-sided posteroventral pallidotomy. Postoperatively, his hemidystonia improved over a period of a few weeks. The Unified Dystonia Rating Scale improved by 84%. He maintained the improvements for the 2-year postoperative follow-up period. No complications were encountered. Clinical presentation, surgical techniques, and surgical results are presented. In conclusion, hemidystonia may significantly respond to a contralateral posteroventral pallidotomy.

[Early postoperative assessment of cognitive functions after stereotactic pallidotomy in patients with primary dystonia - preliminary results]

BACKGROUND AND PURPOSE

The newest studies notify that globus pallidus, besides the motor control, plays an important role in cognitive functioning of: memory, attention, linguistic skills, visuospatial ability, and executive functions. Stereotactic pallidotomy (the lesion of the motor region of the globus pallidus) is one of the surgery options that is used in the treatment of the primary dystonia. Motor region is located in the postero-ventral part of the internal globus pallidus. The goal of the study was to assess of the influence of pallidotomy on cognitive functioning in the group of patients suffering from the primary dystonia.

MATERIAL AND METHODS

Eighteen patients diagnosed with primary dystonia were treated by stereotactic pallidotomy and they were investigated neuropsychologically. The study was performed between March 2004 and February 2005. Neuropsychological assessment was conducted 1-2 days prior to operation and 2 days following the surgery. The clinical course of the cognitive functions and emotional status were assessed by the following neuropsychological tests: Mini Mental State Examination (MMSE), Trail Making Test A and B (TMT A and B), Stroop Color-Word Interference Test, N-back Test, Auditory Verbal Learning Test (AVLT), Benton Visual Retention Test (BVRT), Wisconsin Card Sorting Test (WCST), Beck Depression Inventory (BDI), Montgomery-Asberg Depression Rating Scale (MADRS).

RESULTS

The statistically significant differences have been obtained between the results before and after the surgery in the depression scales: BDI (p<0.02) and in MADRS (p<0.01). None of the neuropsychological tests revealed significant differences between the results before and after the surgery. The only trend (p=0.06-0.07) was noted between results of AVLT before and after the surgery. The average results were worse after the surgery in the first, fifth and sixth attempt of the reply.

CONCLUSIONS

Stereotactic pallidotomy has not significantly changed cognitive functions in the patients suffering from primary dystonia. Whereas, the emotional state has significantly improved in consequence of the applying surgery. Stereotactic pallidotomy in primary dystonia seems to be a treatment option safe for the patients' cognitive functions.

[Neurosurgical management of dystonias]

Dystonia is not a rare condition and there are more than 10 patients per 100,000 general population. In recent years various neurosurgical interventions have been proven to be effective for various types of dystonias. For example, generalized dystonia involving whole the body and resulting in bed-ridden state can be dramatically improved with stereotactic chronic deep brain stimulation of the globus pallidum interna. Cervical dystonia is the most common among dystonias and exhibits symptoms of spasmodic torticollis. The first treatment of choice is local injection of botulinum toxin. But if the symptoms are refractory to the conservative treatment, selective peripheral denervation of the involved muscles is a well-established safe and effective surgical method. Task-specific focal hand dystonia, often called as writer's cramp, is no longer a psychogenic condition. Ventrooralis thalamotomy interrupting the oscillatory hyperactive cortico-pallido-thalamic circuit results in excellent relief of the symptom. of writer's cramp. Thus, in the modern era of functional neurosurgery, we neurosurgeons should regard most dystonias as a definite neurosurgical condition. In this review, we describe the current state of neurosurgical treatment for dystonias.

Treatment of dystonia

Dystonia, defined as a neurological syndrome characterised by involuntary, patterned, sustained, or repetitive muscle contractions of opposing muscles, causing twisting movements and abnormal postures, is one of the most disabling movement disorders. Although gene mutations and other causes are increasingly recognised, most patients have primary dystonia without a specific cause. Although pathogenesis-targeted treatment is still elusive, the currently available symptomatic treatment strategies are quite effective for some types of dystonia in relieving involuntary movements, correcting abnormal posture, preventing contractures, reducing pain, and improving function and quality of life. A small portion of patients have a known cause and respond to specific treatments, such as levodopa in dopa-responsive dystonia or drugs that prevent copper accumulation in Wilson's disease. Therapeutic options must be tailored to the needs of individual patients and include chemodenervation with botulinum toxin injections for patients with focal or segmental dystonia, and medical treatments or deep brain stimulation for patients with generalised dystonia.

Outcome of patients after Achilles tendon lengthening for treatment of idiopathic toe walking

Fifteen children who were diagnosed with idiopathic toe walking that cannot be corrected by nonoperative treatment were assessed by clinical examination and computer-based gait analysis preoperatively and approximately 1 year after Achilles tendon lengthening. Passive dorsiflexion improved from a mean plantarflexion contracture of 8 degrees to dorsiflexion of 12 degrees after surgery. Ankle kinematics normalized, with mean ankle dorsiflexion in stance improving from -8 to 12 degrees and maximum swing phase dorsiflexion improving from -20 to 2 degrees. Peak ankle power generation increased from 2.05 to 2.37 W/kg but did not reach values of population norms. No patient demonstrated clinically relevant triceps surae weakness or a calcaneal gait pattern. Seven patients had a stance phase knee hyperextension preoperatively, and 6 of these corrected after surgery. Achilles tendon lengthening improves ankle kinematics without compromising triceps surae strength; however, plantarflexion power does not reach normal levels at 1 year after surgery.

An update on functional neuroimaging of parkinsonism and dystonia

PURPOSE OF REVIEW

The aim of this article is to review current advances in functional magnetic resonance imaging and positron emission tomography of the motor system in parkinsonism and dystonia.

RECENT FINDINGS

In Parkinson's disease, recent functional magnetic resonance imaging studies have shown that the pattern of regional activity changes in the motor system are strongly modulated by the amount of attention patients pay to task performance. In focal hand dystonia, functional magnetic resonance imaging has disclosed several functional alterations in the basal ganglia in addition to the well-known cortical abnormalities. Neuroimaging has also been successfully used to assess the impact of pharmacological or surgical interventions. In patients with monogenetically inherited parkinsonism or dystonia, positron emission tomography and functional magnetic resonance imaging have opened up exciting possibilities to link molecular biology with functional changes at a systems level. Neuroimaging of genetically defined at-risk populations has shown great potential to study motor reorganization at the preclinical stage and to identify adaptive mechanisms that prevent or delay clinical manifestation.

SUMMARY

Functional neuroimaging plays a key role in understanding the pathophysiology of parkinsonism and dystonia. A future challenge will be to clarify how these disorders impair the functional integration within the motor system and how these changes in connectivity are influenced by therapeutic interventions.

Treatment of dystonia

Dystonia may be a sign or symptom, that is comprised of complex abnormal and dynamic movements of different etiologies. A specific cause is identified in approximately 28% of patients, which only occasionally results in specific treatment. In most cases, treatment is symptomatic and designed to relieve involuntary movements, improve posture and function and reduce associated pain. Therapeutic options are dictated by clinical assessment of the topography of dystonia, severity of abnormal movements, functional impairment and progression of disease and consists of pharmacological, surgical and supportive approaches. Several advances have been made in treatment with newer medications, availability of different forms of botulinum toxin and globus pallidus deep brain stimulation (DBS). For patients with childhood-onset dystonia, the majority of whom later develop generalized dystonia, oral medication is the mainstay of therapy. Recently, DBS has emerged as an effective alternative therapy. Botulinum toxin is usually the treatment of choice for those with adult-onset primary dystonia in which dystonia usually remains focal. In patients with secondary dystonia, treatment is challenging and efficacy is typically incomplete and partially limited by side effects. Despite these treatment options, many patients with dystonia experience only partial benefit and continue to suffer significant disability. Therefore, more research is needed to better understand the underlying cause and pathophysiology of dystonia and to explore newer medications and surgical techniques for its treatment.

[A study on outcome of surgical treatment for focal dystonia]

OBJECTIVE

To analysis the outcome of stereotactic nucleus lesioning for focal dystonia patients.

METHODS

Twenty-three focal dystonia patients were divided into 2 groups according to etiological factor. Stereotactic nucleus lesioning was performed for 10 primary dystonia patients of group A and 13 secondary patients of group B. The change of motor function was investigated and matched between 2 groups after 6 months follow-up.

RESULTS

Significant improvement of motor abilities was observed in patients of group A. The mean improvement of patients of group B was 43.8%. And the individual difference of improvement was obvious in patients of group B.

CONCLUSIONS

Stereotactic nucleus lesioning displays a satisfactory therapeutic effect for patients of writer's cramp. The efficacy of nucleus lesioning for secondary focal dystonia patients depends on the extensive of brain functional lesion. A structurally normal brain is not certainly a predictor of good response to surgical treatment.

Dystonia

BACKGROUND

Dystonia refers to a syndrome of sustained muscle contractions, frequently causing twisting and repetitive movements or abnormal postures. Although age at onset, anatomic distribution, and family history are essential elements in the evaluation of dystonia, new classification increasingly relies on etiologic and genetic data. In recent years, much progress has been made on the genetics of various forms of dystonia and its pathophysiology underlying the clinical signs. The treatment of dystonia has continued to evolve to include newer medications, different forms of botulinum toxin, and various surgical procedures.

REVIEW SUMMARY

In this article, the author reviewed and summarized the history of dystonia, its evolving classification, and recent genetic data, as well as its clinical investigation and treatment.

CONCLUSIONS

Recent advances in molecular biology have led to the discovery of novel dystonia genes and loci, updating classification schemes, and better understanding of underlying pathophysiology. Treatment strategies for dystonia have significantly been updated with the introduction of different forms of botulinum toxin therapy, new pharmacologic agents, and most recently pallidal deep brain stimulation. A systematic approach to the diagnosis and treatment evaluation of dystonic patients provides optimal care for long-term management.

Multimodal neurosurgical strategies for the management of dystonias

Dystonia have many subtypes, and is classified as focal, segmental and generalized. As for focal dystonia, spasmodic torticollis (cervical dystonia) and writer's cramp are most common. Cervical dystonia is mainly treated effectively with selective peripheral denervation, and task specific focal dystonia of the hand (writer's cramp) is effectively alleviated by stereotactic ventro-oral thalamotomy. Generalized dystonia is dramatically improved with deep brain stimulation of the globus pallidus interna. Because the majority of dystonia is medically refractory and surgical treatment results in marked improvement, the authors strongly believe that dystonia should be regarded as a definite neurosurgical indication. Based on personal experience of nearly 200 cases of dystonia surgery, the authors describe a multimodal approach to various types of dystonias. Also we discuss possible relation between dystonias and psychiatric conditions, and future new indication of dystonia surgery.

Destructive stereotactic surgery for treatment of dystonia

BACKGROUND

This study is a retrospective review of the results of stereotactic destructive surgery in selected cases of drug-resistant dystonia.

METHODS

Fifty-eight patients with drug-resistant dystonia were treated with stereotactic surgery between 1991 and 1999 in our institution. These patients' charts were retrospectively analyzed. The timing of the conducted evaluations was as follows: preoperatively, postoperatively, in the postoperative 1st week, 6th month, 12th month, and also thereafter every year.

RESULTS

Symptoms of dystonia occurred before the age of 10 years in 30 patients (51.8%) and after the age of 10 years in 28 patients (48.2%). Generalized dystonia was detected in 41 patients, whereas 11 patients had hemidystonia, 5 patients had focal dystonia, and 1 patient had segmental dystonia. The most common etiologic factor was CP (n = 34). A total of 103 ablative lesions were created in 86 surgical sessions. Thalamotomy, pallidotomy, subthalamotomy, and the region of Forel lesions were performed either separately or in combination. In this series, the mean follow-up time was 102.2 months. Except for 2 cases of temporary hemiparesis, no other complications were observed. Minor improvement was obtained in 17 patients (19.7%), improvement of a medium degree was obtained in 17 patients (19.7%), high-degree improvement was obtained in 11 (12.8%), and very high degree improvement was obtained in 16 (18.6%) patients. A final evaluation revealed permanent improvement in 32 patients (55.2%).

CONCLUSION

Production of stereotactic destructive lesions in certain specified targets is a safe method that improves quality of life and aids ambulation in patients with dystonia resistant to medical therapy.

[Therapy of dystonia in Japan]

A questionnaire about the treatment of dystonia was sent out to 585 councilors of Societas Neurologica Japonica. One hundred and sixty-eight replies (28.7%) were collected, although some of them were excluded from the analysis because of inappropriateness. 1) The number of patients previously experienced was < 10; 37 respondents (22.7%), 10-50; 83 (50.9%), 50-100; 26 (16.0%), and > 100; 17 (10.4%). 2) Oral medication was most often the first line treatment in either of generalized dystonia, blapharospasm, cervical dystonia, and writer's cramp. Botulinum toxin injection was the first or the second line treatment in 147 (87.5%) and 116 (69.0%) respondents for blepharospasm and cervical dystonia, respectively. In these two conditions, the more experienced doctors tended to prefer botulinum toxin injection to the other treatments as the first choice (Cochran-Armitage analysis; p = 0.003 for blepharospasm and p = 0.002 for cervical dystonia). 3) Among the oral drugs, anticholinergics, especially trihexyphenidyl, were the most frequent choice in generalized dystonia, cervical dystonia, and writer's cramp. For blepharospasm, clonazepam was most favored. Sedatives, especially diazepam, were also often the drug of choice in either of these disorders. The favored drugs were not related to the respondent's experience. 4) The success rate of treatment, designated as the percentage of patients who improved through any treatment so much that the respondent was satisfied with it, was the highest in blepharospasm (65.4 +/- 24.1; mean +/- SD), followed by cervical dystonia (41.2 +/- 23.4), writer's cramp (32.9 +/- 22.5), and generalized dystonia (20.4 +/- 19.8). Only in cervical dystonia, the rate was significantly higher in more experienced respondents (regression analysis; p = 0.008). In blepharospasm (p < 0.001) and cervical dystonia (p = 0.002), regression analysis indicated that the success rate was higher in the group who preferred botulinum toxin injection to oral medication as the first line treatment. These results indicate that in Japan the treatment of choice for dystonia does not always follow the therapeutic guidelines for dystonia proposed in some foreign countries. Adopting more evidence-based rationale of treatment is encouraged, because the recent progress about the treatment of dystonia, e.g. botulinum toxin injection or the stereotaxic surgery, is reshaping dystonia from a devastating to a treatable disorder.

Pallidal stimulation for dystonia

OBJECTIVE

High-frequency deep brain stimulation (DBS) of the globus pallidus internus (GPi) is a new and promising treatment option for severe dystonia. Yet only few studies have been published to date regarding this treatment. We present the results of DBS of the GPi in 17 patients with severe dystonia of different causes.

METHODS

In our study, we included 10 patients with primary generalized dystonia, six patients with secondary generalized dystonia, and one patient with a severe dystonic cervical tremor. In all patients, DBS electrodes were implanted bilaterally within the GPi. Mean follow-up time was 36 months (range, 12-66 mo). Preoperative and postoperative evaluations (at least annually) were performed using the Burk-Fahn-Marsden scale.

RESULTS

The best improvement was achieved in patients with DYT1-positive dystonia. Patients with DYT1-negative generalized dystonia showed inhomogeneous results. There was no significant change in patients with tardive dystonia. One case of Hallervorden-Spatz disease improved dramatically within the first 2 years. The improvement in the cervical dystonic tremor was disappointing, however. Three years after DBS implantation, we found a secondary worsening of symptoms in one patient with a DYT1-positive dystonia and in the patient with Hallervorden-Spatz disease.

CONCLUSION

DBS of the GPi is a new and promising treatment option for dystonia. Secondary worsening may limit this therapy.

Clinical neurophysiology of dystonia

It took decades to accept that dystonia, a bizarre condition which often produces abnormal movements exclusively during specific activities like writing, was due to brain disease. Clinical neurophysiology certainly added to this evolution of thinking. Recent neurophysiological observations demonstrate that dystonia is not only due to an isolated brain motor dysfunction, but also to sensory and sensorimotor integration disturbances. We hope that new treatment strategies will arise thanks to our better understanding of dystonia pathophysiology.

Neuronal activity in the basal ganglia and thalamus in patients with dystonia

OBJECTIVE

To explore the role of abnormal neuronal activity in the basal ganglia and thalamus in the generation of dystonia.

METHODS

Microelectrode recording was performed in the globus pallidus internus (GPi), ventral thalamic nuclear group ventral oral posterior/ventral intermediate, Vop/Vim) and subthalamic nucleus (STN) in patients with primary dystonia (n=11) or secondary dystonia (n=9) during surgery. Electromyogram (EMG) was simultaneously recorded in selected muscle groups. Single unit analysis and cross-correlations were carried out.

RESULTS

Three hundred and sixty-seven neurons were obtained from 29 trajectories (GPi: 13; Vop/Vim: 12; STN: 4), 87% exhibited altered neuronal activity including grouped discharges in GPi (n=79) and STN (n=37), long-lasting neuronal activity (n=70) and rapid neuronal discharge (n=86) in Vop/Vim. There were neurons in Vop, GPi and STN firing at the same frequency as EMG during dystonia (mean: 0.39 Hz, range 0.12-0.84 Hz). Significant correlations between neuronal activity and EMG at the frequency of dystonia were obtained (GPi: r2=0.7 (n=31), Vop/Vim: r2=0.64 (n=18) and STN: r2=0.86 (n=17)).

CONCLUSIONS

Consistent with previous findings of abnormalities observed in Vop/VIM and GPi in relation to dystonia, the present data further show that the altered activity in GPi, specifically in dorsal subregions of GPi, Vop/Vim and STN is likely to be directly involved in the production of dystonic movement. Dystonia-related neuronal activity observed in motor thalamus and basal ganglia nuclei of GPi and STN indicates a critical role of their interactions affecting both indirect and direct pathways in the development of either generalized or focal dystonia.

SIGNIFICANCE

These data support a central role of the basal ganglia in producing dystonic movements.

Long term motor complications of levodopa: clinical features, mechanisms, and management strategies

Levodopa is the most effective symptomatic treatment of Parkinson's disease. However, after an initial period of dramatic benefit, several limitations become apparent including, "dopa resistant" motor symptoms (postural abnormalities, freezing episodes, speech impairment), "dopa resistant" non-motor signs (autonomic dysfunction, mood and cognitive impairment, etc), and/or drug related side effects (especially psychosis, motor fluctuations, and dyskinesias). Motor complications include fluctuations, dyskinesias, and dystonias. They can be very disabling and difficult to treat. Therefore, strategies should ideally be developed to prevent them. Though mechanisms underlying motor complications are only partially understood, recent work has revealed the importance of pulsatile stimulation of postsynaptic dopamine receptors and the disease severity. As a result of intermittent stimulation there occurs a cascade of changes in cell signalling leading to upregulation of the N-methyl-D-aspartate subtype of gamma-aminobutryric acid-ergic neurones. Modified preparations of levodopa (controlled release preparations, liquid levodopa), catecholamine-o-methyltransferase inhibitors, dopamine agonists, amantidine, and various neurosurgical approaches have been used in the prevention and/or treatment of motor complications. Current management of motor complications is less than satisfactory. With better understanding of the pathogenetic mechanisms, it is hoped that future therapeutic strategies will provide a safer and targeted treatment.

Neuronal globus pallidus activity in patients with generalised dystonia

We studied 516 globus pallidus neurons in dystonic patients. The firing rate was analysed. We classified the burst activity into tonic, burst, and pause patterns. Mean +/- SD firing rates and tonicity score for internal globus pallidus (GPi) and external globus pallidus (GPe) were 54.6 +/- 28.6; 58.01 +/- 39.1 and 1.18 +/- 0.55; 0.95 +/- 0.43, respectively. Differences in percentage appearance of tonic, burst, or paused neurons were not statistically significant for GPi versus GPe. GPi firing features in dystonic patients were closely similar to those of GPe. This could suggest that the abnormally patterned output from GPi would not result from increased differential inhibitory/excitatory input arising from the direct/indirect pathway but rather be transmitted from GPe, striatum, or either centromedian nucleus.

Deep brain stimulation for dystonia confirming a somatotopic organization in the globus pallidus internus

Object. In patients with dystonia, symptoms vary greatly in their extent and severity. The efficacy of pallidal stimulation is now established, but an interindividual variability in the responses to this treatment exists. A retrospective analysis of postoperative magnetic resonance (MR) images demonstrated millimetric variations in the positions of electrode contacts inside the posterolateroventral portion of the globus pallidus internus (GPi). It therefore seemed very likely that there is a somatotopic organization within the GPi. The goal of this study was to examine the positions of specific electrode contacts according to patients' clinical evolution, so that a somatotopic organization within the GPi could be defined.

Methods. This study included 19 patients (17 of whom were right handed) with generalized dystonia who were treated by bilateral stimulation of the GPi. Patients were examined pre- and postoperatively by using the Burke-Fahn-Marsden Dystonia Rating Scale. Dividing the patient's body into three parts—cervicoaxial area, superior limb, and inferior limb—we determined the following: 1) where the dystonic symptoms started; 2) where symptoms predominated at the time of surgery; and 3) where the highest postoperative improvement was observed.

Variations in clinical response were correlated to the positions of the electrode contacts. All activated electrode contacts were in the posterolateroventral portion of the GPi (Laitinen target). A correlation between the contact location measured longitudinally and the part of the body in which the highest improvement was observed (three different areas; p = 0.004) showed that a location more anterior for the inferior limb and one more posterior for the superior limb were delineated for the right side, but not for the left side.

Conclusions. Inside the posterolateroventral subvolume of the GPi on the right side, three statistically different locations of electrode contacts were determined to be primary deep brain stimulation treatment sites for particular body parts in cases of dystonia.

Neurosurgical management of abnormal muscle tone in childhood

No longer are only a limited number of treatments available to help children and their families deal with childhood hypertonia. It is now possible to provide a child with a treatment specific to his or her muscle tone problems and consequently meet the family's functional goals. The prospects can only improve over the next few years, given the level of interest exhibited by pediatric neuro- and orthopedic surgeons supported by pediatricians, pediatric physical and occupational therapists, pediatric neurologists, and pediatric physiatrists.

Patterning of globus pallidus local field potentials differs between Parkinson's disease and dystonia

Here we test the hypothesis that there are distinct temporal patterns of synchronized neuronal activity in the pallidum that characterize untreated and treated parkinsonism and dystonia. To this end we recorded local field potentials (LFPs) from the caudal and rostral contact pairs of macroelectrodes implanted into the pallidum of patients for the treatment of Parkinson's disease (12 cases recorded on and off medication, 17 macroelectrodes) and dystonia (10 cases, 19 macroelectrodes). Percentage LFP power in the 11-30 Hz band was decreased and that in the 4-10 Hz band increased across both contact pairs in treated Parkinson's disease compared with untreated Parkinson's disease. Dystonic patients had even less 11-30 Hz power and greater 4-10 Hz power compared with untreated or treated Parkinson's disease patients. The change in the 4-10 Hz band in patients with dystonia was particularly manifest in the more rostral contact pair, presumed to be within or bridging the globus pallidus externus. We conclude that untreated and treated Parkinson's disease and dystonia are characterized by different spatiotemporal patterns of activity in the human pallidum.

Functional posterior rhizotomy for severely disabled children with mixed type cerebral palsy

The authors evaluated the impact of functional posterior rhizotomy (FPR) for children with severely disabled mixed type cerebral palsy (CP). Three quadriplegic children at the age of 3, 4, and 10 years underwent FPR. They were classified as mixed type CP based on the clinical presentation of marked spasticity with dystonic posture. Preoperative Ashworth score of the lower extremity was 3.5, 4.5, 4.8 respectively. Two children showed prominent opisthotonus and all showed severe subluxation of the hip joint. Advanced scoliosis was associated in two children. FPR was performed from L2 to S1 in one child, L2 to S2 in one and L2 to S1/S2 in one based on the result of pudendal mapping. Rootlet cutting rate ranged from 66 to 75%. Postoperatively, Ashworth score dropped to 1.4, 1.2, 1.3, respectively. Functional improvement of the upper extremity and urination were confirmed in two children. Hip subluxation was reduced in one child and remained stable in two. A one-year follow-up review confirmed no relapse of spasticity among them. FPR achieved highly satisfactory surgical effects in children with severe mixed type CP. Although long-term follow-up is mandatory since there was a report of relapsed spasticity after FPR in this particular population of CP, FPR could be a choice of surgery in severely disabled children with mixed type CP.

Placement of deep brain stimulators into the subthalamic nucleus or Globus pallidus internus: technical approach

Deep brain stimulation (DBS) represents a major advance in the treatment of Parkinson's disease (PD). As more neurosurgeons enter this field, technical descriptions of implantation techniques are needed. Here we present our technical approach to subthalamic nucleus (STN) and globus pallidus internus (GPi) DBS implantation, based on 180 STN implants and 75 GPi implants. The essential steps in DBS implantation are magnetic resonance imaging (MRI)-guided stereotactic localization, confirmation of the motor territory of the target nucleus with microelectrode mapping, and intra-operative test stimulation to determine voltage thresholds for stimulation-induced adverse effects. Lead locations are documented by postoperative MRI in all cases.

[Parkinsonian dystonia]

Dystonias are frequently observed in Parkinson's disease or other parkinsonian syndromes. They can occur during off-periods, either in the morning (early morning dystonia) or during daily off-periods, and during on-periods. Dystonia involves more frequently the upper and lower limbs, the neck or the face. Dystonia can be painful in particular off-period feet dystonia. The mechanisms underlying dystonia are not fully understood, basal ganglia activity and levodopa levels seems to play an important role. There are several medical options to try and improve those dystonias, adjustment of levodopa doses, adding a dopamine agonist drug, anticholinergics, lithium, baclofene or clonazepam. Those options are not always very effective. Botulinum toxin injections are an alternative treatment for focal dystonia. Muscles have to be selected by observation of the dystonia. Deep muscles in particular in the legs can be injected under EMG guidance. Botulinum toxin injections are particularly helpful and safe for lower limb dystonia. They can be used also for other forms of dystonia. Upper limb dystonia can be injected, allowing more comfort and easier hygiene but not necessarily better function, weakness is the main side effect. Cervical dystonia, blepharospam and oromandibular dystonia can be managed the same way as idiopathic dystonia. The dose might be lower since the muscles are usually not as hypertrophic. Side effects are as expected dysphagia and neck weakness in case of cervical dystonia, ptosis, inocclusion and diplopia in case of blepharospasm, jaw opening difficulty with oromandibular dystonia. Basal ganglia surgery can also help dystonia in a selected population of parkinsonian patients.

Neurosurgical treatment of spasticity and other pediatric movement disorders

For children whose spasticity and movement disorders are inadequately treated by oral medications and botulinum toxins, neurosurgical procedures are now available to effectively treat spasticity, tremor, and many cases of dystonia. Spastic diplegia can be treated with selective lumbar rhizotomies, which significantly decrease spasticity, increase range of motion, and improve Gross Motor Function Measure scores. Children with spastic quadriparesis and those with secondary dystonia can be treated with intrathecal baclofen, which diminishes both spasticity and dystonia and is associated with improved function and quality of life. Children with primary dystonia and those with tremor can be treated with deep brain stimulation of the internal globus pallidus and thalamus, respectively. Some children with chorea respond to deep brain stimulation. There are no effective neurosurgical treatments for athetosis or ataxia. The effectiveness of neurosurgical treatments of pediatric movement disorders has increased significantly in the past 15 years.

Fifty years of brain surgery for dystonia: revisiting the Irving S. Cooper's legacy, and looking forward

As dystonia may represent a severe disease with possible fatal outcome or physical or social incapacity, and considering the limited efficacy of drug treatments (excepted doparesponsive dystonia), efforts have been made since the 1950s to propose alternative treatment. In this paper, an overview of the works done by neurosurgeons over fifty years to treat severe dystonia is presented. In this area of therapeutical research, the pioneering contribution of Irving Cooper is presented and discussed, and the way his publications were evaluated emphasized. Undoubtedly, Cooper observed striking improvement after performing basal ganglia lesions in patients with generalized dystonia, even in the long term. It should be noted that he early made almost the same statements as today's preliminary observations regarding the clinical criteria for the selection of good responders to brain functional surgery. However, the message was lost, given the amount of critics Cooper received, and probably, the way he required to present them. This point emphasize the need we are today to carry out carefully designed, controlled, double-blind studies in this area.

Surgical therapy for dystonia

Surgical treatments for dystonia have been available since the early 20th century, but have improved in their efficacy to adversity ratio through a combination of technologic advances and better understanding of the role of the basal ganglia in dystonia. The word "dystonia" describes a phenotype of involuntary movement that may manifest from a variety of conditions. Dystonia may affect only certain regions of the body or may be generalized. It appears to be critical to determine whether the etiology underlying the dystonia is "primary" (ie, occurring from a genetic or idiopathic origin) or "secondary" (ie, occurring as a result of structural, metabolic, or neurodegenerative disorders). Secondary dystonias are far more common than primary dystonias. Primary dystonias respond well to pallidotomy or deep brain stimulation of the internal segment of the globus pallidum, whereas secondary dystonias appear to respond partially at best. Limited historic and current data suggest that the thalamus may be a promising target for the treatment of secondary dystonias, but more careful, prospective, randomized studies are needed. Combinations of bilateral targets are possible with the current technology of DBS, but not widely used due to surgical morbidity and expense. This article reviews the surgical treatment of dystonia from past to present, with a focus on separating the outcomes for primary versus secondary and generalized versus cervical dystonia.