Surgical considerations for tremor and dystonia

Deep brain stimulation (DBS) is among the most effective approaches for the treatment of patients with advanced movement disorders. In patients with essential tremor, stimulation typically targets the ventral intermediate nucleus of the thalamus. Results of several studies have shown that over a follow-up period of 1 to 5 years, the severity of tremor decreases by an average of approximately 50% from baseline. Ongoing research continues to define the optimal stimulation parameters for patients with tremor, including frequency, voltage, and pulse width. In patients with dystonia, DBS typically targets the globus pallidus internus or the subthalamic nucleus. Long-term prospective clinical trials demonstrated reductions in motor severity rating scale scores of approximately 50% to 80% over follow-up periods of 2 to 3 years. Serious adverse events were uncommon, and included lead failures and infections. Appropriate candidates for DBS treatment of dystonia include patients with an unequivocal diagnosis of dystonia and significant disability. Several issues in the use of DBS for movement disorders remain unresolved, including the intensity of appropriate medical management before undergoing DBS, the importance of intraoperative mapping, optimal stimulator programming, and the time course of the beneficial effects of treatment.     

Combined therapy of orthopedic surgery after deep brain stimulation in cerebral palsy mixed type - a case report -

Dystonia is a symptom defined by involuntary and irregular contractions of the muscles, which cause movement disorders and postural problems. Deep brain stimulation (DBS) in globus pallidus interna (GPi) is a good option for controlling dystonia. DBS has already been shown to have significant effects on primary dystonia as well as Parkinson's disease. Dystonia is very difficult to manage, as seen in cerebral palsy (CP) mixed with spasticity. As CP patients grow, their musculoskeletal problems may require orthopedic surgery. However, the outcome of orthopedic surgery is not usually suitable due to dystonia. Therefore, we attempted to control dystonia through DBS initially and perform orthopedic surgery to correct musculoskeletal deformities after treatment of dystonia. Herein, we report a case that showed remarkable improvement in terms of the dystonia rating scale and gait pattern after combined therapy of DBS and orthopedic surgery.     

Neurosurgery for movement disorders.

Movement disorders have been treated neurosurgically since the 1930s. Current diagnoses for neurosurgical interventions are Parkinson's disease, essential tremor, multiple sclerosis, and some dystonic disorders such as idiopathic torsions dystonia. By using stereotactic image-guided techniques, targets can be chosen to treat different symptoms: the ventrointermediate nucleus of thalamus for tremor; the internal globus pallidus for dyskinesia, dystonia, rigidity, akinesia, and tremor; and the subthalamic nucleus for all cardinal symptoms in advanced Parkinson's disease, including drug-induced hyperkinesia (secondary to reduced drugs). The surgical approaches can be divided into three main groups: destructive (e.g., lesional surgery), reversible and adjustable (e.g., permanent electro-inhibition/stimulation), and reconstructive (e.g., fetal nerve cell transplantation). Reconstructive procedures, which are not discussed here, are still in the early developmental phase. All the methods have advantages and disadvantages; therefore, it is important that the right target and technique be chosen for each patient.     

Deep brain stimulation for movement disorders: patient selection and technical options

Deep brain stimulation (DBS) is used as a treatment for movement disorders. Unlike ablative procedures, DBS is reversible and adjustable. It is approved in the United States for treatment of Parkinson disease (PD), dystonia, and tremor. This surgical procedure is considered safe and effective for the management of the motor symptoms of these disorders, although it does not cure the underlying conditions. Potential complications of DBS surgery include intracranial hemorrhage, infections, and complications related to the hardware. There may also be complications related to stimulation or programming, although these are usually associated with dosages of dopaminergic medications and are reversible. DBS is usually performed under conscious sedation with awake evaluation during intraoperative physiologic testing. Typically, the procedure is performed with stereotactic image guidance, using computed tomography or magnetic resonance imaging (MRI) for targeting. Surgery can be accomplished with stereotactic frames or frameless systems. Recently, intraoperative MRI guidance has become available and is an alternative to the traditional surgical procedure, allowing for implantation of the DBS device under general anesthesia.     

Deep brain stimulation for advanced Parkinson's disease

Deep brain stimulation (DBS) is a new and promising technique for the treatment of movement disorders. Medically intractable Parkinson's disease (PD) is one of the most common indications for DBS. There are three possible subcortical targets for PD, depending on the symptomatology (i.e., the motor subdivision of the thalamus, the globus pallidus internus, the subthalamic nucleus [STN]). Thalamic stimulation has been well established as a safe and effective treatment for essential tremor and the tremor associated with PD. Globus pallidus internus and STN DBS are being investigated for the treatment of all the cardinal signs of PD. This article describes the pathophysiology of PD, the surgical treatment history of PD, surgical techniques used for DBS implants, and the role the perioperative nurse has in the care of the patients undergoing these procedures.     

Deep brain stimulation: current and future clinical applications

Deep brain stimulation (DBS) has developed during the past 20 years as a remarkable treatment option for several different disorders. Advances in technology and surgical techniques have essentially replaced ablative procedures for most of these conditions. Stimulation of the ventralis intermedius nucleus of the thalamus has clearly been shown to markedly improve tremor control in patients with essential tremor and tremor related to Parkinson disease. Symptoms of bradykinesia, tremor, gait disturbance, and rigidity can be significantly improved in patients with Parkinson disease. Because of these improvements, a decrease in medication can be instrumental in reducing the disabling features of dyskinesias in such patients. Primary dystonia has been shown to respond well to DBS of the globus pallidus internus. The success of these procedures has led to application of these techniques to multiple other debilitating conditions such as neuropsychiatric disorders, intractable pain, epilepsy, camptocormia, headache, restless legs syndrome, and Alzheimer disease. The literature analysis was performed using a MEDLINE search from 1980 through 2010 with the term deep brain stimulation, and several double-blind and larger case series were chosen for inclusion in this review. The exact mechanism of DBS is not fully understood. This review summarizes many of the current and potential future clinical applications of this technology.     

Functional brain networks and abnormal connectivity in the movement disorders

Clinical manifestations of movement disorders, such as Parkinson's disease (PD) and dystonia, arise from neurophysiological changes within the cortico-striato-pallidothalamocortical (CSPTC) and cerebello-thalamo-cortical (CbTC) circuits. Neuroimaging techniques that probe connectivity within these circuits can be used to understand how these disorders develop as well as identify potential targets for medical and surgical therapies. Indeed, network analysis of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has identified abnormal metabolic networks associated with the cardinal motor symptoms of PD, such as akinesia and tremor, as well as PD-related cognitive dysfunction. More recent task-based and resting state functional magnetic resonance imaging studies have reproduced several of the altered connectivity patterns identified in these abnormal PD-related networks. A similar network analysis approach in dystonia revealed abnormal disease related metabolic patterns in both manifesting and non-manifesting carriers of dystonia mutations. Other multimodal imaging approaches using magnetic resonance diffusion tensor imaging in patients with primary genetic dystonia suggest abnormal connectivity within the CbTC circuits mediate the clinical manifestations of this inherited neurodevelopmental disorder. Ongoing developments in functional imaging and future studies in early patients are likely to enhance our understanding of these movement disorders and guide novel targets for future therapies.     

Fast-track programming and rehabilitation model: a novel approach to postoperative deep brain stimulation patient care

OBJECTIVE: To propose a new model of integrated, multidisciplinary postoperative care of the patients with deep brain stimulation (DBS). DESIGN: Observational cohort study with follow-up at 3 months and 1 year. SETTING: Academic medical center movement disorder clinic. PARTICIPANTS: Seventy-three consecutive patients with medically refractory Parkinson's disease underwent bilateral DBS. Patients were then transferred directly to an inpatient rehabilitation facility. INTERVENTION: DBS and inpatient programming and rehabilitation. Simultaneous programming and rehabilitation was carried out by a multidisciplinary team. MAIN OUTCOME MEASURES: The FIM instrument, Unified Parkinson Disease Rating Scale (UPDRS), and levodopa dosage. RESULTS: The average rehabilitation stay was 17.3 days, with a mean of 6.2 stimulator adjustments during that time. FIM scores improved from 62.1 (admission) to 98.5 (discharge), an average improvement of 36.4 (58.6%). Average UPDRS scores improved from 52.5 (preoperative off) and 30.1 (preoperative on) to 20.4 (3mo postoperative on-medication, on-stimulation), a 32.2% improvement from the preoperative on score. Levodopa dosages decreased by an average of 48.3% (all P<.001). CONCLUSIONS: We describe our fast-track protocol, which allows for rapid DBS programming and tapering of Parkinson's medications. It also provides for treatment of concomitant medical and psychologic problems and optimized physical performance.     

Understanding essential tremor. Differential diagnosis and options for treatment

Although essential tremor is common, its various presentations may be confused with other movement disorders, such as Parkinson's disease and dystonic tremor. In this article, Dr Evidente describes classification of tremor, the clinical features of essential tremor, and the differential diagnostic considerations. He also discusses the extensive list of medications used to treat the disorder and the surgical options for severe, drug-resistant cases.     

脑慢性深部电刺激治疗难治性帕金森病及特发性震颤

目的 应用脑慢性深部电刺激 (DBS)治疗难治性帕金森病 (PD)及特发性震颤 (ET),并对其疗效作出评价。方法 对 6例 PD患者及 2例 ET患者采用磁共振导向立体定向及术中电生理验证方法。将刺激电极分别植入丘脑腹中间核及丘脑底核,并同期植入刺激发生器。结果 6例患者术后获得了显著的疗效,震颤完全消失,肌张力恢复正常,步态、姿势明显改善,未出现任何并发症。结论 DBS作为目前最理想的手术方法治疗药物难治性 PD、 ET,具有极少副作用、可逆转性的优点,能完全控制震颤,明显改善肌张力障碍、步态、姿势等运动障碍。     

What is new in movement disorders?

Movement disorders is a term applied for a heterogeneous group of diseases and syndromes sharing deficits of voluntary motor function or movement patterns. In clinical practice, the term movement disorders is usually employed to designate those syndromes and diseases that are linked to a pathology or dysfunction of cortico-basal ganglia circuits. The last years have witnessed a rapid expansion in our understanding of the etiological and pathophysiological factors underlying movement disorders such as Parkinson's disease or dystonia. The discovery of new gene mutations is bound to give rise to new insights into the molecular pathogenesis of movement disorders related to neurodegenerative processes. It is already becoming apparent that pathological protein aggregation may be a common link in the neuronal degeneration underlying such diverse entities as spinocerebellar ataxia, idiopathic torsion dystonia and Parkinson's disease. So far, these new findings have not been translated into new forms of symptomatic or preventive therapies. Nevertheless, symptomatic treatment of movement disorders, as evident in the field of Parkinson's disease, is one of the most rewarding and innovative areas of neurological therapy.     

Proposed guidelines for videotaping individuals with movement disorders.

Standardized rating scales for Parkinson's disease and dystonia have been validated and are now widely accepted as useful clinical assessment tools. However, the other movement disorders have been more difficult to quantify. The use of a standardized videotape protocol can provide a more precise audiovisual record of the movement disorder patient. With broader use by others and further revisions, these guidelines can be improved in order to provide an accurate assessment and teaching tool. The authors welcome comments.     

Drug-induced and tardive movement disorders.

Drug-induced and tardive movement disorders represent a large number of extrapyramidal disorders seen in neurologic practice. Iatrogenically induced, most commonly by neuroleptics, these disorders can be characterized by any abnormal body movement including tremor, chorea, athetosis, dyskinesias, dystonia, myoclonus, tics, ballismus or akathisia. Parkinsonism, dyskinesias and dystonia tend to be the most common. Management of patients with drug-induced or tardive syndromes is complex. Prognosis is frequently poor as patients usually need the offending agent to manage their underlying psychiatric or medical problem. Neuroleptics and other drugs known commonly to cause movement disorders should be used cautiously and significant consideration of all risks and benefits measured before initiating therapy.     

Indication of surgical therapy for Parkinson's disease

We review the current status of surgical treatment of Parkinson's disease (PD). The advantages of deep brain stimulation (DBS) over ablative surgery include reversibility and controllability of stimulation. In addition, DBS carries a smaller risk of side effects, especially when employed bilaterally. DBS of the thalamus is useful to control tremor which is unresponsive to medication. DBS of the globus pallidus internus (GPi) or the subthalamic nucleus (STN) is useful to control wearing off of motor symptoms which is difficult to manage with medication alone. DBS of STN and GPi improves motor function mainly during the off-period. DBS of STN attenuates levodopa-induced dyskinesia through reduction of dopa requirement, whereas DBS of GPi attenuates dopa-induced dyskinesia directly. DBS of STN is also useful to control symptoms of PD in patients who are intolerant to dopa. However, DBS of either STN or GPi cannot reverse advanced symptoms of PD, which are unresponsive to dopa.     

CLUSTER

The authors observed a high rate of suicide (6/140 patients, 4.3%) in a large cohort of patients with movement disorders treated with deep brain stimulation (DBS). Apparent risk factors included a previous history of severe depression and multiple successive DBS surgeries, whereas there was no relationship with the underlying condition, DBS target, electrical parameters, or modifications of treatment. Paradoxically, all patients experienced an excellent motor outcome following the procedure. The authors propose that patients at high risk for suicide should be excluded from DBS surgery.
Comment: I included this abstract because of the patients treated with DBS for cluster in Italy and Belgium. The Italian experience has been "five patients operated on … for chronic intractable cluster with the stimulator in the cluster hypothalamic generator with good results and "no relevant side effects" (Leone M, May A, Franzini A, Broggi G, Dodick D, Rapoport A, Goadsby PJ, Schoenen J, Bonavita V, and Bussone G. Deep brain stimulation for intractable chronic cluster headache: proposals for patient selection. Cephalalgia. 2004;24: 934-937) . The Belgian experience " was uneventful in 4 of 5 patients … Unfortunately, one patient developed massive brainstem and basal ganglia hemorrhage 4 hours after surgery and died after 2 days … " (Vendenheede M, Maertens de Noordhout AS, Remacle JM, Mouchamps M, Schoenen J. Deep Brain Stimulation of Posterior Hypothalamus in Chronic Cluster Headache. Neurology. 2004; 62(Suppl5):A356). Add to that death the above concern on suicide, and it is clear that patient selection will be crucial in deciding whether to do this surgery, should it become available in North America, and even then, the hemorrhage and death risk must be confronted.—Stewart J. Tepper, MD     

Drug-induced tremor and acute movement disorders

The main clinical characteristics and aetiology of drug-induced tremor and acute movement disorders (myoclonus, chorea, athetosis, dyskinesia, dystonia, tics) are reviewed and discussed in this article. Tremor is the most frequent drug-induced acute movement disorder. Drug intake (and, initially, true or 'hidden' neuroleptic or psychoactive drugs) should be suspected as the cause of every abnormal movement. Drug-induced acute movement disorders usually disappear spontaneously after withdrawal of the suspected drug without any drug treatment. Drug-induced tremor and movement disorders are often poorly described in the Summary of Products Characteristics (SPC).     

Case study of a young man with tremor

PURPOSE: To provide the clinician with an opportunity to review the most common causes of tremor in young adults. DATA SOURCES: Extensive review of international scientific literature on tremors and other movement disorders, supplemented by a recent case study. CONCLUSIONS: Essential tremor (ET) is the most common tremor disorder in the world. In contrast to common expectations, the 2nd decade of life represents a period of peak incidence. The early presentation may be so mild that the tremor goes unnoticed by patients and clinicians for many years. The most important movement disorder to rule out in the workup of patients with tremors is Parkinson's disease. IMPLICATIONS FOR PRACTICE: The diagnosis of ET is generally made on clinical grounds. A comprehensive history and careful physical examination that rules out cerebellar or extrapyramidal disease is required. The clinician must distinguish between resting tremors and action tremors. If the appropriate diagnosis is unclear, a tremor recording (electromyogram) may assist in this distinction. Referral to a neurologist may be warranted.     

Movement disorders and botulinum toxin in neurology

Botulinum toxin has been a useful treatment in many movement disorders and more recently in other non-neurological motor dysfunctions for more than 15 years. Here, we review the various indications in neurology, mainly in the field of movement disorders. From 1973 to 2002, we searched the Medline database on this topic. We selected the most useful and relevant papers, with a special interest in dystonia. We summarized the results in the main indications (spasmodic torticollis, bleparospasm, hemifacial spasm) and in other manifestations such as writer's cramp, oromandibular dystonia, tremor, tics and myoclonus. We discuss the data of literature and compare them with the experience of the French movement disorders groups.     

Classification of tremor and update on treatment

Tremor is a symptom of many disorders, including Parkinson's disease, essential tremor, orthostatic tremor, cerebellar disease, peripheral neuropathy and alcohol withdrawal. Tremors may be classified as postural, rest or action tremors. Symptomatic treatment is tailored to the tremor type. Combination therapy with carbidopa and levodopa remains the first-line approach for parkinsonian tremor. Essential tremor may be amenable to propranolol or primidone. Propranolol may be useful in treating alcohol withdrawal tremor, and isoniazid may control the cerebellar tremor associated with multiple sclerosis. Clonazepam may relieve orthostatic tremor. Other agents are also available for the treatment of tremor. When medical therapy fails to control the tremor, surgical options such as thalamotomy, pallidotomy and thalamic stimulation should be considered in severe cases. Thalamic stimulation, the most recent of these surgical approaches, offers the advantage over ablative procedures of alleviating tremor without the creation of a permanent lesion.     

High-frequency stimulation of the subthalamic nucleus for the treatment of Parkinson's disease--a team perspective.

Parkinson's disease (PD) is a debilitating neurodegenerative disorder affecting more than 1.2 million people in the United States. Genetic and environmental toxins are believed to be risk factors in acquiring the disease. PD is characterized by tremors, rigidity, bradykinesia, poor gait, and postural instability. These cardinal symptoms improve with medication such a levo-dopa (L-dopa). However, over time, as the disease progresses, the patient becomes refractory to medication, or medication produces debilitating side effects. When this occurs or when there are worsening of symptoms, neurosurgical treatment is recommended, particularly deep brain stimulating (DBS) electrodes implanted in the subcortical subthalamic nucleus (STN). Over the last 5 years STN DBS has gained acceptance and become the neurosurgical treatment of choice for PD. To achieve maximum beneficial effects with minimum adverse effects from the surgery, the expertise of an integrated team of physicians and nurses is essential. A clear understanding of the different aspects of the procedure, including the risks and benefits of the treatment, assists neuroscience nurses in communicating with the PD patient, and providing the most appropriate, knowledge-based pre- and postoperative care.