Deep brain stimulation of the internal pallidum in multiple system atrophy

Deep Brain Stimulation of the Globus Pallidus Internus and Externus in Multiple System Atrophy

BACKGROUND

Multiple system atrophy with parkinsonism (MSA-P) is a progressive condition with no effective treatment.

OBJECTIVE

The aim of this study was to describe the safety and efficacy of deep brain stimulation (DBS) of globus pallidus pars interna and externa in a cohort of patients with MSA-P.

METHODS

Six patients were included. Changes in Movement Disorders Society Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS III), Parkinson's Disease Questionnaire (PDQ-39) scores, and levodopa equivalent daily dose were compared before and after DBS. Electrode localization and volume tissue activation were calculated.

RESULTS

DBS surgery did not result in any major adverse events or intraoperative complications. Overall, no differences in MDS-UPDRS III scores were demonstrated (55.2 ± 17.6 preoperatively compared with 67.3 ± 19.2 at 1 year after surgery), although transient improvement in mobility and dyskinesia was reported in some subjects.

CONCLUSIONS

Globus pallidus pars interna and externa DBS for patients with MSA-P did not result in major complications, although it did not provide significant clinical benefit as measured by MDS-UPDRS III. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Deep brain stimulation for atypical parkinsonism: A systematic review on efficacy and safety

BACKGROUND

Atypical Parkinsonisms (APs) -including progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and dementia with Lewy bodies (DLB)- are neurodegenerative diseases lacking satisfying symptomatic therapies. Deep Brain Stimulation (DBS) is an established neurosurgical option for advanced Parkinson disease (PD). Although DBS effectiveness in PD fed expectations for the treatment of APs, DBS is still not recommended for APs on the basis of expert consensus and lack of clinical trials.

OBJECTIVE

In this systematic review, we sought to analyze current evidence on the safety and efficacy of DBS in APs, discussing clinical indications, anatomical targets, and ethical issues.

METHODS

Following the PRISMA guidelines, we systematically searched PubMed for studies reporting the outcome of patients with APs treated with DBS.

RESULTS

We identified 25 eligible studies for a total of 66 patients with APs treated with DBS: 31 PSP, 22 MSA, 12 DLB, 1 unspecified parkinsonism with tongue tremor. Targeted nuclei were subthalamic nucleus (STN), globus pallidus pars-interna (GPi), pedunculopontine nucleus (PPN), and nucleus basalis of Meynert (nbM). Only 3/25 studies were randomized controlled trials, and most studies showed a high risk of bias.

CONCLUSION

Taking into account study biases and confounding factors, current evidence does not support the use of DBS in APs. However, some interesting insights arise from the literature, such as the high frequency of cognitive/neurobehavioral issues in MSA patients treated with STN-DBS, the low frequency of complications in trials of nbM-DBS for DLB, and the possible good response of dystonic symptoms in PSP with GPi DBS.

Dystonia in atypical parkinsonian disorders

Dystonia is common in the classic atypical parkinsonian disorders such as multiple system atrophy, progressive supranuclear palsy and corticobasal degeneration, and to a lesser extent in dementia with Lewy bodies. Its clinical phenomenology, including body distribution, timing of appearance, severity, and relationship to dopaminergic and other medications may vary considerably within and between atypical parkinsonian disorders. From a pathophysiological standpoint, the coexistence of dystonia with parkinsonism challenges the functional model of the basal ganglia. Clinical recognition of specific dystonic features may assist in the differential diagnosis of atypical parkinsonian disorders and in distinguishing them from Parkinson's disease. The presence of dystonia in atypical parkinsonian disorders informs management decisions. Reduction or withdrawal of levodopa should be considered if there is a close relationship between the onset of dystonia with periods of high dopaminergic tone. Botulinum neurotoxin may be considered in focal presentations. We here provide an updated overview of dystonia arising in the setting of atypical parkinsonian disorders, summarizing relevant clinical and clinicopathological studies, underlying pathophysiological mechanisms, diagnostic clues and potential pitfalls in the diagnosis. Finally, we suggest a tailored therapeutic approach for the management of these patients.

Current Concepts in the Treatment of Multiple System Atrophy

MSA is a progressive neurodegenerative disorder characterized by autonomic failure and a variable combination of poor levodopa-responsive parkinsonism and cerebellar ataxia (CA). Current therapeutic management is based on symptomatic treatment. Almost one third of MSA patients may benefit from l-dopa for the symptomatic treatment of parkinsonism, whereas physiotherapy remains the best therapeutic option for CA. Only midodrine and droxidopa were found to be efficient for neurogenic hypotension in double-blind, controlled studies, whereas other symptoms of autonomic failure may be managed with off-label treatments. To date, no curative treatment is available for MSA. Recent results of neuroprotective and -restorative trials have provided some hope for future advances. Considerations for future clinical trials are also discussed in this review.

Deep brain stimulation in multiple system atrophy mimicking idiopathic Parkinson's disease

Deep brain stimulation (DBS) is approved for idiopathic Parkinson's disease (IPD) but has a poor evidence base in Parkinson-plus syndromes such as multiple system atrophy (MSA). We describe the clinical and neuropathological findings in a man who was initially diagnosed with IPD, in whom DBS was unsuccessful, and in whom MSA was unexpectedly diagnosed at a subsequent autopsy. This case report highlights that DBS is often unsuccessful in MSA and also demonstrates that MSA can masquerade as IPD, which may explain treatment failure in a small group of patients apparently suffering from Parkinson's disease. Additionally, it also presents a case with an unusually long duration of disease prior to death, comparable only to a handful of other cases in the literature.

Tremor in Multiple System Atrophy - a review

BACKGROUND

Multiple system atrophy (MSA) is a rare neurodegenerative movement disorder characterized by a rapidly progressive course. The clinical presentation can include autonomic failure, parkinsonism, and cerebellar signs. Differentiation from Parkinson's disease (PD) is difficult if there is levodopa-responsive parkinsonism, rest tremor, lack of cerebellar ataxia, or mild/delayed autonomic failure. Little is known about tremor prevalence and features in MSA.

METHODS

We performed a PubMed search to collect the literature on tremor in MSA and considered reports published between 1900 and 2013.

RESULTS

Tremor is a common feature among MSA patients. Up to 80% of MSA patients show tremor, and patients with the parkinsonian variant of MSA are more commonly affected. Postural tremor has been documented in about half of the MSA population and is frequently referred to as jerky postural tremor with evidence of minipolymyoclonus on neurophysiological examination. Resting tremor has been reported in about one-third of patients but, in contrast to PD, only 10% show typical parkinsonian "pill-rolling" rest tremor. Some patients exhibit intention tremor associated with cerebellar dysmetria. In general, MSA patients can have more than one tremor type owing to a complex neuropathology that includes both the basal ganglia and pontocerebellar circuits.

DISCUSSION

Tremor is not rare in MSA and might be underrecognized. Rest, postural, action and intention tremor can all be present, with jerky tremulous movements of the outstretched hands being the most characteristic. However, reviewing the data on tremor in MSA suggests that not every shaky movement satisfies tremor criteria; therefore, further studies are needed.

Deep brain stimulation response in pathologically confirmed cases of multiple system atrophy

Deep brain stimulation is a treatment for select cases of medication refractory movement disorders including Parkinson's disease. Deep brain stimulation has not been recommended for treatment in multiple system atrophy patients. However, the paucity of literature documenting the effects of deep brain stimulation in multiple system atrophy patients and the revelation of a levodopa responsive subtype of multiple system atrophy suggests further investigation is necessary. This study summarizes the positive and negative effects of deep brain stimulation treatment in two pathologically confirmed multiple system atrophy patients from the University of Florida Deep Brain Stimulation-Brain Tissue Network. Clinical diagnosis for the two patient cases did not match the neuropathological diagnosis. We noted that in both pathologically confirmed multiple system atrophy patients, death occurred as a result of myocardial infarction. Importantly, there was reported transient benefit in levodopa responsive features that indicate deep brain stimulation may be an option for select multiple system atrophy patients.

Multiple system atrophy: current and future approaches to management

Multiple system atrophy (MSA) is a rare neurodegenerative disorder without any effective treatment in slowing or stopping disease progression. It is characterized by poor levodopa responsive Parkinsonism, cerebellar ataxia, pyramidal signs and autonomic failure in any combination. Current therapeutic strategies are primarily based on dopamine replacement and improvement of autonomic failure. However, symptomatic management remains disappointing and no curative treatment is yet available. Recent experimental evidence has confirmed the key role of alpha-synuclein aggregation in the pathogenesis of MSA. Referring to this hypothesis, transgenic and toxic animal models have been developed to assess candidate drugs for MSA. The standardization of diagnosis criteria and assessment procedures will allow large multicentre clinical trials to be conducted. In this article we review the available symptomatic treatment, recent results of studies investigating potential neuroprotective drugs, and future approaches for the management in MSA.

Deep brain stimulation of the pedunculopontine nucleus in a patient with freezing of gait

CASE PRESENTATION

A 54-year-old male patient presenting probable multiple system atrophy with predominant parkinsonism who underwent bilateral deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) is presented. The patient had dominant freezing of gait (FOG), levodopa-resistant bradykinesia, and autonomic disturbances, but with a good cognitive condition.

METHODS

The patient underwent bilateral DBS of the PPN, which ended with modest benefits.

RESULTS AND CONCLUSION

Although he had a short postoperative follow-up (6 months), his neurological status remained stable and PPN DBS provided modest improvements in the gait disorder and freezing episodes. This unusual case suggests that the mesencephalic pedunculopontine region may have a role in locomotor symptoms and the potential to provide a limited improvement in FOG.

Event-related desynchronization of motor cortical oscillations in patients with multiple system atrophy

Multiple system atrophy (MSA) is a progressive neurodegenerative disease characterized by parkinsonism (MSA-P), cerebellar and autonomic deficits. In Parkinson's disease (PD), an impaired modulation of motor cortical mu and beta range oscillations may be related to the pathophysiology of bradykinesia. Event-related desynchronization (ERD) of these oscillations occur for 1-2 s preceding a voluntary movement in normal subjects and patients with PD treated with levodopa while only lasting around 0.5 s in untreated patients. Motor cortical rhythms were recorded from subdural strip electrodes in three patients with MSA-P while taking their regular dopaminergic medications. Following a ready cue, patients performed an externally cued wrist extension movement to a go cue. In addition, recordings were obtained during imagined wrist extension movements to the same cues and during self-paced wrist extensions. ERD and event-related synchronization were examined in subject-specific frequency bands. All patients showed movement-related ERD in subject-specific frequency bands below ~40 Hz in both externally cued and self-paced conditions. Preparatory ERD latency preceding self-cued movement was 900 ms in one patient and at or after movement onset in the other two patients. In the externally cued task, a short lasting (<1.3 s) ready cue-related ERD that was not sustained to movement onset was observed in two patients. Imagined movements resulted in go cue-related ERD with a smaller magnitude in the same two patients. These results indicate that the modulation of motor cortical oscillations in patients with MSA that are treated with levodopa is similar to that occurring in untreated patients with PD. The findings suggest that cortical activation in patients with MSA is diminished, may be related to pathophysiological changes occurring in the basal ganglia and correlates with the poor clinical response that these patients typically obtain with dopaminergic therapy.

Multiple system atrophy

BACKGROUND

It has been almost 4 decades since the descriptions of the 3 parts of multiple system atrophy (MSA) have taken place, characterized clinically by dysautonomia, parkinsonism, and cerebellar dysfunction. The discovery of a distinctive pathologic maker has finally provided the conceptual synthesis of these 3 entities into the universal designation of MSA as a distinct disease process with a complex combination of clinical presentations. Although advances have been made in terms of awareness and knowledge concerning the clinical features and pathophysiology of MSA, it remains challenging for neurologists who treat these patients to differentiate MSA from its mimics as well as providing them with effective treatment.

REVIEW SUMMARY

The aim of this review is to provide an overview of the advances in the knowledge of the disease, to highlight typical features useful for the recognition of its entity, and to enlist different treatment options.

CONCLUSION

Despite the fact that there is still no treatment modality that can alter the disease progression, a number of useful symptomatic treatment measures are available and should be offered to patients to ameliorate the nonmotor features of MSA and even the motor features that may at least transiently respond to treatment.

[Deep-brain stimulation of the internal pallidum in multiple system atrophy]

INTRODUCTION

The experience with deep-brain stimulation (DBS) in multiple-system atrophy (MSA) is sparse and generally disappointing. DBS is currently not recommended in MSA and its use is often related to a misdiagnosis.

OBSERVATION

We describe the outcome of bilateral DBS of the internal pallidum in a 46-year-old woman suffering from MSA that initially resembled Parkinson's disease with prominent levodopa-induced dyskinesias. DBS of the left internal pallidum was performed in 1998 after a ten-year clinical course and improved dyskinesias. Six months later, the right side was implanted. A few months after the second surgery, the patient progressively developed signs of cerebellar and dysautonomic impairment and MSA was diagnosed.

CONCLUSION

Our observation confirms the ineffectiveness of DBS of the internal pallidum in MSA and even suggests a harmful effect. DBS remains contra-indicated in atypical parkinsonism.

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.

Deep brain stimulation for the treatment of atypical parkinsonism

Deep brain stimulation (DBS) has gained widespread acceptance for improving motor function and disability in Parkinson's disease (PD). Patients with features suggestive of atypical parkinsonism (AP) usually have a poorer and less sustained response to levodopa and a poorer prognosis overall when compared with patients with PD. However, experience in the use of DBS with this group of patients is limited and evidence is lacking with regards to its efficacy and adverse effects. We review in detail the experience of DBS surgery in patients with several forms of AP including multiple system atrophy. On the basis of the limited available data reviewed here, DBS for patients with AP is not recommended.