Dystonia in Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy

Radiological features of cervical spine in dropped head syndrome: a matched case-control study

PURPOSE

Dropped head syndrome (DHS) is presumably caused by focal myopathy in the cervical posterior muscles; however, distinguishable radiological features of the cervical spine in DHS remain unidentified. This study investigated the radiological features of the cervical spine in dropped head syndrome.

METHODS

The records of DHS patients and age- and sex-matched cervical spondylotic myelopathy (CSM) patients were reviewed. Cervical spinal parameters (C2-7, C2-4, and C5-7 angles) were assessed on lateral cervical spine radiographs. Quantitative radiographic evaluation of cervical spine degeneration was performed using the cervical degenerative index (CDI), which consists of four elements: disk space narrowing (DSN), endplate sclerosis, osteophyte formation, and listhesis.

RESULTS

Forty-one DHS patients were included. Statistically significant differences were noted between the upper and lower cervical spine in the sagittal angle parameters on the neutral, flexion, and extension radiographs in DHS group, whereas no significant differences were observed in CSM group. CDI comparison showed significantly higher scores of DSN in C3/4, C4/5, C5/6, and C6/7; sclerosis in C5/6 and C6/7; and osteophyte formation in C4/5, C5/6, and C6/7 in DHS group than in CSM group. Comparison of listhesis scores revealed significant differences in the upper levels of the cervical spine (C2/3, C3/4, and C4/5) between two groups.

CONCLUSION

Our results demonstrated that the characteristic radiological features in the cervical spine of DHS include lower-level dominant severe degenerative change and upper-level dominant spondylolisthesis. These findings suggest that degenerative changes in the cervical spine may also play a role in the onset and progression of DHS.

Development of parkinsonism after long-standing cervical dystonia - A cohort

INTRODUCTION

Dystonia occurring in the context of parkinsonism is well-known, e.g. as foot dystonia in young-onset Parkinson's disease (PD), anterocollis in multisystem atrophy (MSA) or blepharospasm (levator inhibition) in progressive supranuclear palsy. We have, however, encountered a series of patients whose phenotype differed from the above described entities.

METHODS

We describe a cohort of patients in whom typical idiopathic isolated (primary) late-onset focal or segmental (predominantly cervical) dystonia preceded the development of parkinsonism by several years, sometimes decades.

RESULTS

In a cohort of 450 patients followed in our botulinum toxin injections clinic, we identified 11 (2.4%; 7 women) who developed parkinsonism at a median of 14 years after the onset of dystonia. Median age at onset of parkinsonism was 70 years (range 59-87), usually manifesting with a new tremor or a change of tremor pattern, complaints of 'slowing down' or new walking difficulties. Parkinsonism resembled PD in 5 (one pathologically confirmed); the remainder had atypical parkinsonism of MSA (n = 3) or indeterminate phenotype (n = 3).

CONCLUSION

The relatively frequent occurrence of parkinsonism after long-standing dystonia would suggest a link between the two, in line with evidence from other clinical reports, imaging studies, animal models and genetics. It appears that in some cases of dystonia this could be an antecedent manifestation of a syndrome with parkinsonism developing later, or be a risk factor for parkinsonism. In practice, it is important for clinicians to be alert to new symptoms/signs in patients with long-standing dystonia. From a research point of view, longitudinal case-control studies would be required to further investigate the link between long-standing dystonia and subsequent parkinsonism.

Acute Postoperative Bilateral Vocal Fold Paralysis After Posterior Spinal Correction for Dropped Head Syndrome

BACKGROUND

Acute bilateral vocal fold paralysis is a life-threatening complication that can occur during spinal surgery but has almost exclusively occurred with anterior approaches. Bilateral vocal fold paralysis after posterior spinal surgery has been exceedingly rare.

CASE DESCRIPTION

We present a case of acute postoperative dyspnea due to vocal fold paralysis requiring intubation and surgical intervention after posterior spinal correction for the treatment of dropped head syndrome. The patient had had a previous diagnosis of atypical Parkinson disease but was later diagnosed with multiple system atrophy.

CONCLUSIONS

We suggest that multiple system atrophy can result in an increased risk of bilateral vocal fold paralysis during surgical intervention of dropped head syndrome. Thus, our report could be of interest for those who perform spinal surgery in patients with neurological conditions.

Impact of Spinopelvic sagittal alignment on the surgical outcomes of dropped head syndrome: a multi-center study

Background

Most of the previous studies about the surgical treatment of dropped head syndrome (DHS) are small case series, and their primary outcome measures were cervical alignment parameters. Therefore, little is known about the associations between pre- and postoperative global sagittal alignment in the whole spine and the clinical outcomes of the surgical treatment of DHS. In this study, we investigated the surgical outcomes of DHS, including correction of cervical and global spinal sagittal alignment.

Methods

This study was a retrospective observational study. Fifteen patients with DHS who had undergone correction surgery were enrolled. Surgical outcomes, including complications and implant failures, were investigated. We assessed cervical alignment parameters as well as spinopelvic global alignment parameters, including pelvic incidence (PI), lumbar lordosis (LL), and C7-sacral sagittal vertical axis (SVA). We examined the changes in these parameters using pre- and posoperative whole spine lateral radiographs. The parameters were compared between the failure and nonfailure groups.

Results

Recurrence of sagittal imbalance and horizontal gaze difficulty was observed in 6 cases (40%). In all, 3 cases (20%) exhibited a distal junctional failure and required multiple surgeries with extension of fusion. Of all the radiographic parameters compared between the failure and nonfailure groups, significant differences were only observed in pre and postoperative SVA and PI-LL.

Conclusions

Our results suggest that the global sagittal alignment parameters, including PI-LL and SVA, were different between the patients with failure and non failure, and these parameters might have notable impacts on surgical outcomes. Surgeons should consider PI-LL and SVA while determining the surgical course for patients with DHS.

Overview of dropped head syndrome (Combined survey report of three facilities)

BACKGROUND

Dropped head syndrome (DHS) is a low prevalence and the clinical features remain unclear. The purpose of the present study was to clarify the general overview of DHS.

METHODS

The subjects were 67 consecutive DHS patients (17 men and 50 women; average age 72.9 ± 10.2 years) presenting difficulty of horizontal gaze in up-right position. The patients' background, global spinal alignment, clinical findings and treatment were analyzed.

RESULTS

The peak population of DHS was 75-79-year-old females. The comorbidities included Parkinson's disease in 9 cases, minor trauma in 9 cases, post-cervical operation in 3 cases, mental depression in 3 cases, malignant tumor in 3 cases, diabetes mellitus in 2 cases and rheumatoid arthritis in 2 cases. The C2-C7 cervical coronal vertical axis was distributed more to the right side (2.6 ± 12.8 mm). Regarding sagittal alignment, 24 cases (35.8%) showed negative balanced DHS (N-DHS) and 43 cases (64.2%) showed positive balanced DHS (P-DHS). There were significant differences in C2-C7 angle, T1S, LL and PI-LL between the two groups. Cervical or back pain was present in 62 cases (92.5%), and average numerical rating scale was 3.0 ± 2.6. Fourteen cases (20.9%) recovered (average 11.3 months), but 29 cases (43.3%) did not recover without surgery. Twenty-four cases (35.8%) underwent surgery, 20 for cervical spine and 4 for thoraco-lumbar spine, and horizontal gaze difficulty was improved in all patients post-surgery.

CONCLUSION

DHS was mainly observed in elderly women. About 20% of DHS patients recovered without surgical treatment. DHS was accompanied by scoliosis in 37.3% of the cases.

Maladaptive striatal plasticity and abnormal reward-learning in cervical dystonia

In monogenetic generalized forms of dystonia, in vitro neurophysiological recordings have demonstrated direct evidence for abnormal plasticity at the level of the cortico-striatal synapse. It is unclear whether similar abnormalities contribute to the pathophysiology of cervical dystonia, the most common type of focal dystonia. We investigated whether abnormal cortico-striatal synaptic plasticity contributes to abnormal reward-learning behavior in patients with focal dystonia. Forty patients and 40 controls performed a reward gain and loss avoidance reversal learning task. Participant's behavior was fitted to a computational model of the basal ganglia incorporating detailed cortico-striatal synaptic learning rules. Model comparisons were performed to assess the ability of four hypothesized receptor specific abnormalities of cortico-striatal long-term potentiation (LTP) and long-term depression (LTD): increased or decreased D1:LTP/LTD and increased or decreased D2: LTP/LTD to explain abnormal behavior in patients. Patients were selectively impaired in the post-reversal phase of the reward task. Individual learning rates in the reward reversal task correlated with the severity of the patient's motor symptoms. A model of the striatum with decreased D2:LTP/ LTD best explained the patient's behavior, suggesting excessive D2 cortico-striatal synaptic depotentiation could underpin biased reward-learning in patients with cervical dystonia. Reversal learning impairment in cervical dystonia may be a behavioral correlate of D2-specific abnormalities in cortico-striatal synaptic plasticity. Reinforcement learning tasks with computational modeling could allow the identification of molecular targets for novel treatments based on their ability to restore normal reward-learning behavior in these patients.

Dystonia and dopamine: From phenomenology to pathophysiology

A line of evidence suggests that the pathophysiology of dystonia involves the striatum, whose activity is modulated among other neurotransmitters, by the dopaminergic system. However, the link between dystonia and dopamine appears complex and remains unclear. Here, we propose a physiological approach to investigate the clinical and experimental data supporting a role of the dopaminergic system in the pathophysiology of dystonic syndromes. Because dystonia is a disorder of motor routines, we first focus on the role of dopamine and striatum in procedural learning. Second, we consider the phenomenology of dystonia from every angle in order to search for features giving food for thought regarding the pathophysiology of the disorder. Then, for each dystonic phenotype, we review, when available, the experimental and imaging data supporting a connection with the dopaminergic system. Finally, we propose a putative model in which the different phenotypes could be explained by changes in the balance between the direct and indirect striato-pallidal pathways, a process critically controlled by the level of dopamine within the striatum. Search strategy and selection criteria References for this article were identified through searches in PubMed with the search terms « dystonia », « dopamine", « striatum », « basal ganglia », « imaging data », « animal model », « procedural learning », « pathophysiology », and « plasticity » from 1998 until 2018. Articles were also identified through searches of the authors' own files. Only selected papers published in English were reviewed. The final reference list was generated on the basis of originality and relevance to the broad scope of this review.

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.

Roles of the M4 acetylcholine receptor in the basal ganglia and the treatment of movement disorders

Acetylcholine (ACh) released from cholinergic interneurons acting through nicotinic and muscarinic acetylcholine receptors (mAChRs) in the striatum have been thought to be central for the potent cholinergic regulation of basal ganglia activity and motor behaviors. ACh activation of mAChRs has multiple actions to oppose dopamine (DA) release, signaling, and related motor behaviors and has led to the idea that a delicate balance of DA and mAChR signaling in the striatum is critical for maintaining normal motor function. Consistent with this, mAChR antagonists have efficacy in reducing motor symptoms in diseases where DA release or signaling is diminished, such as in Parkinson's disease and dystonia, but are limited in their utility because of severe adverse effects. Recent breakthroughs in understanding both the anatomical sites of action of ACh and the mAChR subtypes involved in regulating basal ganglia function reveal that the M₄ subtype plays a central role in regulating DA signaling and release in the basal ganglia. These findings have raised the possibility that sources of ACh outside of the striatum can regulate motor activity and that M₄ activity is a potent regulator of motor dysfunction. We discuss how M₄ activity regulates DA release and signaling, the potential sources of ACh that can regulate M₄ activity, and the implications of targeting M₄ activity for the treatment of the motor symptoms in movement disorders. © 2019 International Parkinson and Movement Disorder Society.

Hand, foot, and spine deformities in parkinsonian disorders

Hand and foot deformities, known as "striatal deformities", and other musculoskeletal abnormalities such as dropped head, bent spine, camptocormia, scoliosis and Pisa syndrome, are poorly understood and often misdiagnosed features of Parkinson's disease and other parkinsonian syndromes. These deformities share some similarities with known rheumatologic conditions and can be wrongly diagnosed as rheumatoid arthritis, osteoarthritis, psoriatic arthritis, Dupuytren's contracture, trigger finger, or other rheumatologic or orthopedic conditions. Neurologists, rheumatologists, and other physicians must be familiar with these deformities to prevent misdiagnosis and unnecessary diagnostic tests, and to recommend appropriate treatment options.

Exploring bedside clinical features of parkinsonism: A focus on differential diagnosis

The proper diagnosis of parkinsonian disorders usually involves three steps: identifying core features of parkinsonism; excluding other causes; and collating supportive evidence based on clinical signs or investigations. While the recognition of cardinal parkinsonian features is usually straightforward, the appreciation of clinical features suggestive of specific parkinsonian disorders can be challenging, and often requires greater experience and skills. In this review, we outline the clinical features that are relevant to the differential diagnosis of common neurodegenerative parkinsonian disorders, including Parkinson's disease, multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration. We aim to make this process relatable to clinicians-in-practice, therefore, have categorised the list of clinical features into groups according to the typical sequence on how clinicians would elicit them during the examination, starting with observation of facial expression and clinical signs of the face, spotting eye movement abnormalities, examination of tremors and jerky limb movements, and finally, examination of posture and gait dysfunction. This review is not intended to be comprehensive. Rather, we have focused on the most common clinical signs that are potentially key to making the correct diagnosis and those that do not require special skills or training for interpretation. Evidence is also provided, where available, such as diagnostic criteria, consensus statements, clinicopathological studies or large multi-centre registries. Pitfalls are also discussed when relevant to the diagnosis. While no clinical signs are pathognomonic for certain parkinsonian disorders, certain clinical clues may assist in narrowing a differential diagnosis and tailoring focused investigations for the individual patient.

Red flags phenotyping: A systematic review on clinical features in atypical parkinsonian disorders

To establish a clinical diagnosis of a parkinsonian disorder, physicians rely on their ability to identify relevant red flags, in addition to cardinal features, to support or refute their working diagnosis in an individual patient. The term 'red flag', was originally coined in 1989 to define the presence of non-cardinal features that may raise a suspicion of multiple system atrophy (MSA), or at least suggest alternative diagnosis to Parkinson's disease (PD). Since then, the term 'red flag', has been consistently used in the literature to denote the clinical history or signs that may signal to physicians the possibility of an atypical parkinsonian disorder (APD). While most red flags were originally based on expert opinion, many have gained acceptance and are now included in validated clinical diagnostic criteria of PD and APDs. The clinical appreciation of red flags, in conjunction with standard criteria, may result in a more accurate and earlier diagnosis compared to standard criteria alone. However, red flags can be clinical signs that are non-neurological, making the systematic assessment for them a real challenge in clinical practice. Here, we have conducted a systematic review to identify red flags and their clinical evidence in the differential diagnosis of common degenerative parkinsonism, including PD, MSA, progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and dementia with Lewy body (DLB). Increasing awareness and appropriate use of red flags in clinical practice may benefit physicians in the diagnosis and management of their patients with parkinsonism.

Comparison of dystonia between Parkinson's disease and atypical parkinsonism: The clinical usefulness of dystonia distribution and characteristics in the differential diagnosis of parkinsonism

OBJECTIVE

Dystonia is occasionally found in patients with Parkinson's disease (PD) and atypical parkinsonisms. However, systematic comparative analysis of the association between dystonia and parkinsonism have seldom been reported. The goals of this study are to compare the clinical characteristics and distributions of dystonia between PD, multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD).

METHODS

We prospectively enrolled 176 patients who presented with dystonia and parkinsonism out of 1278 patients with parkinsonism. We analyzed the clinical features of dystonia and parkinsonism.

RESULTS

The frequencies of dystonia were 11.0% in PD, 20.9% in MSA, 40.7% in PSP and 66.7% in CBD. Dystonia symptoms were most frequent in CBD and relatively more frequent in PSP and MSA (p<0.001). Moreover, multiple types of dystonia occurred most frequently in MSA (p=0.034). According to the distribution of dystonia, cranio-facial dystonia (CFD) and cervical dystonia (CD) were more frequently observed in atypical parkinsonism (p=0.001). In contrast, limb dystonia (LD) was more frequently observed in both PD and CBD, and truncal dystonia (TD) was more frequently detected in PD (p<0.001). Levodopa medication related dystonia was markedly more frequent in PD than in atypical parkinsonism (p=0.030).

CONCLUSIONS

In this long-term, observational, prospective study, we concluded that levodopa medication related LD and TD were more frequently observed in PD than in atypical parkinsonism. Conversely, levodopa medication non-related CFD and CD were more frequently observed in atypical parkinsonism, and coexisting of some types of multiple dystonia may be unique features of atypical parkinsonism. TD or multiple types of LD, might be representative of PD rather than atypical parkinsonism.

Research Priorities in Limb and Task-Specific Dystonias

Dystonia, which causes intermittent or sustained abnormal postures and movements, can present in a focal or a generalized manner. In the limbs, focal dystonia can occur in either the upper or lower limbs and may be task-specific causing abnormal motor performance for only a specific task, such as in writer’s cramp, runner’s dystonia, or musician’s dystonia. Focal limb dystonia can be non-task-specific and may, in some circumstances, be associated with parkinsonian disorders. The true prevalence of focal limb dystonia is not known and is likely currently underestimated, leaving a knowledge gap and an opportunity for future research. The pathophysiology of focal limb dystonia shares some commonalities with other dystonias with a loss of inhibition in the central nervous system and a loss of the normal regulation of plasticity, called homeostatic plasticity. Functional imaging studies revealed abnormalities in several anatomical networks that involve the cortex, basal ganglia, and cerebellum. Further studies should focus on distinguishing cause from effect in both physiology and imaging studies to permit focus on most relevant biological correlates of dystonia. There is no specific therapy for the treatment of limb dystonia given the variability in presentation, but off-label botulinum toxin therapy is often applied to focal limb and task-specific dystonia. Various rehabilitation techniques have been applied and rehabilitation interventions may improve outcomes, but small sample size and lack of direct comparisons between methods to evaluate comparative efficacy limit conclusions. Finally, non-invasive and invasive therapeutic modalities have been explored in small studies with design limitations that do not yet clearly provide direction for larger clinical trials that could support new clinical therapies. Given these gaps in our clinical, pathophysiologic, and therapeutic knowledge, we have identified priorities for future research including: the development of diagnostic criteria for limb dystonia, more precise phenotypic characterization and innovative clinical trial design that considers clinical heterogeneity, and limited available number of participants.

Comparison of clinical features in pathologically confirmed PSP and MSA patients followed at a tertiary center

BACKGROUND/OBJECTIVES

The clinical diagnosis of progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) remains challenging due to heterogeneity of the diseases.

AIMS

Here we compared the clinical features of PSP and MSA to gain insight into their diagnosis and prognosis, particularly the prognostic value of down-gaze palsy latency in PSP progression.

METHODS

We reviewed clinical features of pathologically confirmed 10 PSP and 13 MSA patients, incidentally matched in age-at-onset, gender, and disease duration, followed at Columbia University Medical Center during 1994-2009.

RESULTS

The final antemortem diagnosis was incorrect in 30% of PSP (all lacking down-gaze palsy) and 23% of MSA patients. Falls in the first year of the disease, pyramidal involvement and freezing of gait during the course were similar between PSP and MSA. Ataxia and apraxia were in 50% of the PSP patients. Parkinsonism responsive to levodopa treatment was in 30% of the PSP (all with resting tremor) and 50% of the MSA patients. Dysautonomia in MSA could occur as early as 3 years preceding the motor symptoms, with 46% within the first year of the motor onset, but 15% did not have dysautonomia in life. The latency of down-gaze palsy and urogenital dysfunction and MMSE scores at first visit in PSP, and the latency of falls and wheelchair confinement in MSA were all associated with the disease progression.

CONCLUSIONS

We confirmed most of the previously published characterizations, and identified for the first time the prognostic value of down-gaze palsy latency in PSP progression.

Dropped head syndrome preceding the onset of dementia with Lewy bodies

A 67-year-old woman developed dropped head. Her neck was severely flexed, with prominent cervical paraspinal muscles, although no parkinsonism was observed. Brain MRI showed no significant findings. We considered dystonia as the cause of the dropped head and administered trihexyphenidyl, an anticholinergic. After 10 years of follow-up, remarkable psychotic symptoms, including hallucinations regarding insects, appeared. Following the discontinuation of trihexyphenidyl, the psychotic symptoms decreased but still remained. (123)I-N-isopropyl-p-iodoamphetamine single-photon emission computed tomography ((123)I-IMP SPECT) revealed hypoperfusion in the bilateral occipital lobes. We diagnosed the patient with dementia with Lewy bodies (DLB). This case suggests that dropped head syndrome may precede the onset of DLB.

The focal dystonias: current views and challenges for future research

The most common forms of dystonia are those that develop in adults and affect a relatively isolated region of the body. Although these adult-onset focal dystonias are most prevalent, knowledge of their etiologies and pathogenesis has lagged behind some of the rarer generalized dystonias, in which the identification of genetic defects has facilitated both basic and clinical research. This summary provides a brief review of the clinical manifestations of the adult-onset focal dystonias, focusing attention on less well understood clinical manifestations that need further study. It also provides a simple conceptual model for the similarities and differences among the different adult-onset focal dystonias as a rationale for lumping them together as a class of disorders while at the same time splitting them into subtypes. The concluding section outlines some of the most important research questions for the future. Answers to these questions are critical for advancing our understanding of this group of disorders and for developing novel therapeutics.

Postural disorders in Parkinson’s disease: clinical characteristics, frequency, pathophysiology and management

SUMMARY Postural disorders are frequently observed in Parkinson’s disease patients and significantly affect patients’ quality of life. They may develop because of increased muscle tonus, which results in shortened muscle fibers and induces contracted postures and subsequent changes in muscles, connective tissue, bones and peripheral nerves. Enhanced muscle tonus may induce forward and/or lateral flexion of the spine. Abnormal postures usually occur in the middle or later stages of the disease, and are often reversible in the supine position. Forward flexion, lateral flexion and, less frequently, antecollis are the common axial postural disorders in Parkinson’s disease patients. While antiparkinsonian drugs may improve these symptoms, they may also induce or worsen them. As postural disorders become irreversible after the development of secondary changes, such as muscle atrophy and bone fracture, physicians should recognize postural disorders at early stages.

Clinical subtypes of anterocollis in parkinsonian syndromes

BACKGROUND

Disproportionate anterocollis is a debilitating condition which occurs in the later stages of parkinsonian syndromes and for which there is no effective therapy. Multiple hypotheses have been proposed to explain its underlying etiology, including myopathy of the cervical extensors, and dystonia of the cervical flexors.

METHODS

We examined the records of 39 patients (8 prospectively) with anterocollis and parkinsonian syndromes to explore demographics, historical and clinical data, findings from electromyography and response to therapies. We classified our patients based on whether or not they were weak on neck extension and also based on primary diagnosis (PD vs atypical parkinsonian syndrome). Demographic, clinical, historical and EMG features are reported for each group.

RESULTS

There were no significant demographic differences between clinical subtypes, or primary diagnosis. Electromyographic (EMG) findings demonstrated myopathic changes in both groups, although they were more prominent in the group which was weak in extension. Historical features were similar between groups except for dopamine agonist use, which was more common in the myopathic subgroup (p=0.02). There were no other significant clinical differences between clinical subtypes or primary diagnosis with the exception that patients with atypical parkinsonian syndromes had more advanced motor symptoms.

CONCLUSIONS

We conclude that anterocollis is a heterogeneous condition in which at least two distinct subtypes exist. Recognizing these subtypes may help guide therapy and future research.

Update on the pathology of dystonia

Dystonia is a clinical syndrome with sustained muscle contraction, twisting, and abnormal postures. A number of different genetic forms have been defined, but most cases are sporadic in nature and of uncertain cause. Relatively few cases of dystonia have been studied pathologically. In primary dystonias, where dystonia is the main symptom, most reports describe little or no detectable neuropathology, although changes in brainstem neurons have been described in some cases. Secondary dystonias are associated with degenerative or destructive diseases of the nervous system; the pathology may be located in the basal ganglia, but in some cases the primary pathological changes are found in the cerebellum or cerebellar outflow pathways, suggesting that both regions may be involved in the pathogenesis of dystonic symptoms. Overall the number of well-documented pathological cases available for study is few, and there is an urgent need for additional postmortem studies. This article is part of a Special Issue entitled "Advances in dystonia".

The functional neuroanatomy of dystonia

Dystonia is a neurological disorder characterized by involuntary twisting movements and postures. There are many different clinical manifestations, and many different causes. The neuroanatomical substrates for dystonia are only partly understood. Although the traditional view localizes dystonia to basal ganglia circuits, there is increasing recognition that this view is inadequate for accommodating a substantial portion of available clinical and experimental evidence. A model in which several brain regions play a role in a network better accommodates the evidence. This network model accommodates neuropathological and neuroimaging evidence that dystonia may be associated with abnormalities in multiple different brain regions. It also accommodates animal studies showing that dystonic movements arise with manipulations of different brain regions. It is consistent with neurophysiological evidence suggesting defects in neural inhibitory processes, sensorimotor integration, and maladaptive plasticity. Finally, it may explain neurosurgical experience showing that targeting the basal ganglia is effective only for certain subpopulations of dystonia. Most importantly, the network model provides many new and testable hypotheses with direct relevance for new treatment strategies that go beyond the basal ganglia. This article is part of a Special Issue entitled "Advances in dystonia".

Focal limb dystonia

Limb dystonia (LD) refers to dystonia affecting one arm or leg. Depending on the site of onset, age at onset, and the etiology, progression and prognosis will be different. Usually young-onset primary dystonia affects the lower limbs and tends to generalize, while in adult-onset, it appears in the arm and remains focal. Lower limb dystonia in adults is rare as a primary cause, and parkinsonism or other neurological diseases must always be ruled out. In the text that follows, we review the main clinical features of the primary and secondary limb dystonias considering the age at onset and etiology.

Dopamine agonist-induced antecollis in Parkinson's disease

Few cases of dopamine agonist-induced antecollis in Parkinson's disease (PD) have been reported. Literature review of 16 PD patients including our 3 cases with dopamine agonist-induced antecollis showed predominance of (1) Japanese, (2) women, and (3) Hoehn-Yahr stage of >or=3. We experienced three Japanese PD patients who subacutely exhibited antecollis following increased dopamine agonist dose that improved just after withdrawal of the agonist. One patient developed antecollis during increasing pramipexole dose in combination with cabergoline. Antecollis in another patient appeared during increasing pramipexole dose; it worsened after substituting pergolide for pramipexole, but improved after withdrawal of pergolide. Our cases indicate that there is no specific dopamine agonist causing antecollis, and it is possibly caused by a number of single dopamine agonists or a combination of them. Dopamine agonist-induced antecollis should be considered when encountering antecollis in PD patients being treated with dopamine agonists and withdrawal of the agonist can improve symptoms.

Clinical features of dystonia in atypical parkinsonism

BACKGROUND: The association between Dystonia and Parkinson's disease (PD) has been well described especially for foot and hand dystonia. There is however few data on dystonic postures in patients with atypical parkinsonism. OBJECTIVE: To evaluate the frequency and pattern of dystonia in a group of patients with atypical parkinsonism (multiple system atrophy - MSA, progressive supranuclear palsy - PSP, and corticobasal degeneration - CBD) and to investigate whether dystonia could be the first presenting symptom at disease onset in those patients. METHOD: A total of 38 medical charts were reviewed (n=23/MSA group; n=7/CBD group; n=8/PSP group) and data values were described as means/standard deviations. The variables evaluated were sex, age at onset, disease duration, first symptom, clinical features of dystonia and other neurological signs, response to levodopatherapy, Hoehn&Yahr scale >3 after three years of disease, and magnetic resonance imaging findings. RESULTS: The overall frequency of dystonia in our sample was 50% with 30.4% (n=7) in the MSA group, 62.5% (n=5) in the PSP group, and 100% (n=8) in the CBD group. In none of these patients, dystonia was the first complaint. Several types of dystonia were found: camptocormia, retrocollis, anterocollis, blepharoespasm, oromandibular, and foot/hand dystonia. CONCLUSION: In our series, dystonia was a common feature in atypical parkinsonism (overall frequency of 50%) and it was part of the natural history although not the first symptom at disease onset. Neuroimaging abnormalities are not necessarily related to focal dystonia, and levodopa therapy did not influence the pattern of dystonia in our group of patients.

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.

Voxel-based morphometry and voxel-based relaxometry in multiple system atrophy-a comparison between clinical subtypes and correlations with clinical parameters

Multiple system atrophy (MSA) is a neurodegenerative disease affecting basal ganglia, brainstem, cerebellum, and intermediolateral cell columns of the spinal cord. Clinically, a cerebellar (MSA-C) and a parkinsonian variant of MSA (MSA-P) are distinguished. We used voxel-based morphometry (VBM) and voxel-based relaxometry (VBR) in 48 MSA patients (32 MSA-C, 16 MSA-P) and 46 controls. In MSA-C, VBM revealed gray matter loss in cerebellum, right thalamus, both putamina and several cortical regions including insular cortex. Gray matter loss in the cerebellum and insular cortex was correlated with disease duration and severity. There was white matter loss in the brainstem, which was correlated with disease duration and severity. VBR analysis in MSA-C showed decreased relaxation rate R2 in cerebellum, pontine brainstem and cortical regions including insular cortex. In MSA-P, gray matter was reduced in cerebellum, dorsal midbrain, both putamina, and several cortical regions including insular cortex. A correlation with disease duration and severity was detected only for some small cortical areas. Direct comparison of MSA-C and MSA-P showed differences only in infratentorial brain regions where structural abnormalities were more pronounced in MSA-C than in MSA-P. In MSA-C, there was a stronger reduction of gray matter in the basal parts of the cerebellum, of white matter in the brainstem and of the relaxation rate R2 in the cerebellum and brainstem.

Joint and skeletal deformities in Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy

The objective of this study is to characterize clinical features of joint and skeletal deformities in Parkinson's disease (PD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Clinical information including age, gender, presence of deformity, initial symptom side, neuropsychological and motor features, family history, and treatment with levodopa/dopamine agonists was collected on consecutive patients with PD, MSA, and PSP evaluated at the Movement Disorders Clinic at Baylor College of Medicine. In this series of 202 patients, 36.1% had deformities of the limbs, neck, or trunk, including 33.5% of PD, 68.4% of MSA, and 26.3% of PSP patients. "Striatal" hand and foot deformities were present in 13.4%, involuntary trunk flexion in 12.9%, anterocollis in 9.4%, and scoliosis in 8.4% of all patients. Patients with these joint and skeletal deformities had higher mean Unified Parkinson's Disease Rating Scale scores (57.4 vs. 46.6; P < 0.01) and were more often treated with levodopa (69.9% vs. 50.4%; P < 0.01) than patients without deformity, independent of disease duration. Patients with striatal deformity were younger than patients without deformity (mean 60.4 vs. 68.6 years; P < 0.01), and they tended to have an earlier age of onset of initial parkinsonian symptoms (mean 54.7 vs. 62.5 years; P < 0.01). Furthermore, the side of striatal deformity correlated with the side of initial parkinsonian symptoms in all patients (100%) with striatal hand and in 83.3% of patients with striatal foot. Joint and skeletal deformities are common and frequently under-recognized features of PD, MSA, and PSP that often cause marked functional disability independent of other motor symptoms.

Dropped head syndrome in Parkinson's disease

We determined the frequency of dropped head syndrome in Parkinson's disease (PD) in Japan and evaluated its clinical correlates. A total of 252 consecutive patients with PD who visited our hospital were studied. Dropped head syndrome was found in 15 patients (6.0%) (3 men, 12 women; mean age at onset of PD, 62.8 +/- 11.5 years). The interval before emergence of dropped head after disease onset was 5.4 +/- 4.3 years (-0.5 to 15 years). The Hoehn-Yahr score at the on stage was 3.2 +/- 0.7; at the off stage 3.5 +/- 0.8. Of those 15 patients, 8 had major symptoms of rigidity and akinesia. In 2 patients, administration of a dopamine agonist appeared to evoke dropped head syndrome. An increase in and/or the addition of antiparkinsonian drugs alleviated head drop in 4 patients and reduced head drop in 7 patients. Any medication was not effective for 4 patients. Dropped head syndrome in PD is not rare in Japan. It is more often observed in women and is associated with patients who primarily suffer rigidity and akinesia. Dropped head syndrome in these patients appears to be produced by disproportionate tonus of the neck muscles. It is modulated by antiparkinsonian drugs and is considered to be a type of dystonia.

Dystonia in Parkinson’s disease

Dystonia can occasionally be found in idiopathic Parkinson's disease. It is very uncommon in untreated patients and is more frequently seen as a complication of its treatment. In this review, the various types of dystonia occurring in PD, the differential diagnosis with other parkinsonian syndromes associated with dystonia and treatments available are revised. Dystonia unrelated to treatment can be typical (blepharospasm, torticollis), atypical (parkinsonian writer's cramp, camptocormia, anismus), or occurring in earlyonset Parkinson disease (the so-called kinesigenic foot dystonia, considered a hallmark of early-onset Parkinson's disease). Early and prominent dystonia in untreated patients with parkinsonism should raise the suspicion of other entities other than Parkinson's disease, such as progressive supranuclear palsy, multiple system atrophy or corticobasal degeneration. In patients on chronic dopaminergic treatment, peak-dose dystonia, diphasic dystonia and off-dystonia can be seen. The later constitutes the major dystonic feature of chronic levodopa therapy, and a wide variety of strategies are available to manage this complication. Among them, deep brain stimulation of the subthalamic nucleus has proved to be the most effective one. Dystonic reactions (mainly involving oculomotor cranial nerves and limbs) in operated patients (especially carriers of deep brain stimulation (DBS) devices) are increasingly being reported, constituting a new type of dystonia in patients with Parkinson's disease: dystonia linked to surgical treatment.

Striatal deformities of the hand and foot in Parkinson's disease

Striatal deformities of the hand and foot are abnormal postures that are common in patients with advanced Parkinson's disease (PD); they can present in the early stages of PD and in other parkinsonian disorders. Over a century ago, Charcot and Purves-Stewart recognised these deformities, which cause substantial functional disability and discomfort. The term striatal is used because pathology in the neostriatum (putamen and caudate) has been suggested to cause the deformities, but the pathogenesis is unknown. Misdiagnosis of the deformities is common-particularly when they occur early and in the absence of cardinal parkinsonian signs, such as tremor, bradykinesia, and rigidity-because the hand deformities are similar to those in rheumatoid arthritis, equinovarus foot deformity typically suggests an orthopaedic problem, and toe extension may be thought to be the Babinski sign of upper-motor-neuron syndromes. Here we review the background and clinical features of these deformities to highlight these commonly unrecognised and poorly understood parkinsonian signs.

Marked asymmetry of putaminal pathology in an MSA-P patient with Pisa syndrome

We report on an autopsy case of a 62-year-old Japanese woman with a 2.5-year history of axial dystonia. She presented with a form of axial dystonia reminiscent of Pisa syndrome. The pathophysiological mechanism underlying forms of axial dystonia remains to be elucidated. We report here the histopathological findings of a multiple system atrophy of parkinsonian predominance (MSA-P) patient with Pisa syndrome.

Severe cervical dystonia in pathologically proven Parkinson's disease and dementia

We describe and present a videotape of a patient with parkinsonism and dementia who developed severe cervical dystonia, despite treatment with levodopa and botulinum toxin. The clinical diagnosis of Parkinson's disease and dementia (PDD) was confirmed at autopsy.

Blepharospasm associated with multiple system atrophy: a case report and review of the literature

Although blepharospasm has been occasionally associated with parkinsonism, it has rarely been reported in patients with multiple system atrophy (MSA). We report a 65-year-old woman with MSA who developed blepharospasm seven years after onset, rendering her functionally blind. Clinical course and the findings of magnetic resonance imaging indicated cerebellar type MSA. The blink reflex studies showed prolonged R2 response and enhanced recovery cycle, indicating an increased excitability of the brainstem interneurons. These results suggest that pathophysiology of blepharospasm in MSA is similar to that of essential blepharospasm. Recognition of blepharospasm in MSA patients is important, as blepharospasm is a treatable feature in this otherwise intractable disorder.

Asymmetrical awake bruxism associated with multiple system atrophy

We describe a 51-year-old man who developed awake bruxism during the course of multiple system atrophy. Electromyographic studies revealed side-to-side amplitude asymmetry of the bursts of motor activity. The bruxism responded favourably to low-dose levodopa-carbidopa therapy. Possible mechanisms of this rare association are discussed.

Diagnostic accuracy of progressive supranuclear palsy in the Society for Progressive Supranuclear Palsy Brain Bank

Diagnostic accuracy has been addressed previously for Parkinson's disease in a brain bank collection, but accuracy of progressive supranuclear palsy (PSP) has not been addressed in a similar setting. Clinical and genetic features of pathologically confirmed cases of PSP were compared with misdiagnosed cases to determine ways to improve diagnostic accuracy. Medical records were reviewed for 180 cases sent to the Society of Progressive Supranuclear Palsy Brain Bank that had standardized neuropathologic evaluations as well as determination of apolipoprotein E and tau genotypes. Of the 180 cases studied, 137 had PSP and 43 had other pathologic diagnoses. Corticobasal degeneration (CBD), multiple system atrophy (MSA), and diffuse Lewy body disease (DLBD) accounted for 70% of the misdiagnosed cases. History of tremor, psychosis, dementia, and asymmetric findings were more frequent in misdiagnosed cases. The frequency of H1 tau haplotype (93 vs. 80%) and H1H1 genotype (86 vs. 66%) were significantly greater and APOE epsilon4 carrier state was significantly less (17 vs. 41 %) in PSP compared with misdiagnosed cases. Pathologic evaluation of clinically diagnosed PSP remains important for definitive diagnosis, and CBD, MSA, and DLBD are the disorders most likely to be misdiagnosed as PSP. Tremor, psychosis, early dementia, asymmetric findings, absence of H1 haplotype, and presence of APOE epsilon4 should raise questions about a diagnosis of PSP.

Levodopa-induced oromandibular dystonia in progressive supranuclear palsy

Levodopa-induced dyskinesias have been reported in Parkinson's disease and multiple system atrophy. Cranial dystonias are rare in patients with progressive supranuclear palsy (PSP). In this report we describe an unusual case of reversible levodopa-induced Oromandibular dystonia (OMD) in a PSP patient to highlight the importance of recognizing this drug related complication in the management of PSP, and discuss the possible underlying pathophysiology.

Parkinsonism in multiple system atrophy: natural history, severity (UPDRS-III), and disability assessment compared with Parkinson's disease

We analyzed parkinsonian features in multiple system atrophy (MSA) compared with age- and disease duration-matched Parkinson's disease (PD) patients, and assessed the applicability of the Unified Parkinson's Disease Rating Scale (UPDRS) -III motor scale as a means of rating their severity. Cross-sectional analysis of parkinsonism was done using UPDRS-III, International Cerebellar Atatia Rating Scale, and disability scales (Hoehn and Yahr [H&A], Schwab and England, Katz and Lawton) in 50 unselected MSA patients and in 50 matched PD patients. At symptom onset, falls occurred 10 times more frequently in MSA, whereas limb tremor was 10 times more common in PD. At first visit (10.2 months), hemiparkinsonism and pill-rolling rest tremor were less common in MSA. Hypomimia, atypical rest, postural or action tremor, as well as postural instability were more frequent in MSA. At study examination (62.4 months), parkinsonian signs in MSA patients were more frequently symmetrical and associated with axial rigidity, antecollis and postural instability. A levodopa response of >50% was seen in <10% of MSA patients. Modified H&Y stages (3.2 +/- 1.3 vs. 2.2 +/- 0.78) and UPDRS-III scores (48.14 +/- 19.5 vs. 31.74 +/- 12.9) were significantly (P = 0.0001) higher in MSA. The internal consistency of the UPDRS-III was fair in MSA patients (Cronbach's alpha >0.90), and correlated well with marked dependency on the Schwab and England and Katz and Lawton scales. Factor structure analysis of UPDRS-III in MSA showed five clinically distinct subscores accounting for 74% of the variance, differing from PD by the dependency of the face-speech and limb bradykinesia items and independence of the postural-action tremor from the rest tremor items. There was a significant correlation (R(2) = 0.70, P = 0.001) between ICARS ataxia and UPDRS-III scores in MSA patients. Results confirm a distinct profile of parkinsonism in MSA and greater severity and disability compared with PD. It also indicates that the UPDRS-III provides a useful severity measure of parkinsonism in MSA, albeit contaminated by additional cerebellar dysfunction.

Dystonia in multiple system atrophy

OBJECTIVE

To delineate the frequency and nature of dystonia in multiple system atrophy (MSA).

METHODS

A cohort of 24 patients with clinically probable MSA over the past 10 years were prospectively followed up. Motor features were either dominated by parkinsonism (MSA-P subtype, n=18) or cerebellar ataxia (MSA-C, n=6). Classification of dystonic features and their changes with time was based on clinical observation during 6-12 monthly follow up visits. Parkinsonian features and complications of drug therapy were assessed. Most patients (22/24) died during the observation period. Neuropathological examination was confirmatory in all of the five necropsied patients.

RESULTS

At first neurological visit dystonia was present in 11 (46%) patients all of whom had been levodopa naive at this time point. Six patients (25%) exhibited cervical dystonia (antecollis) (MSA-P n=4, MSA-C n=2), five patients (21%) showed unilateral limb dystonia (MSA-P n=4; MSA-C n=1). A definite initial response to levodopa treatment was seen in 15/18 patients with MSA-P, but in none of the six patients with MSA-C. A subgroup of 12 patients with MSA-P developed levodopa induced dyskinesias 2.3 years (range 0.5-4) after initiation of levodopa therapy. Most patients had peak dose craniocervical dystonia; however, some patients experienced limb or generalised dystonia. Isolated peak dose limb chorea occurred in only one patient.

CONCLUSION

The prospective clinical study suggests that dystonia is common in untreated MSA-P. This finding may reflect younger age at disease onset and putaminal pathology in MSA-P. Levodopa induced dyskinesias were almost exclusively dystonic affecting predominantly craniocervical musculature. Future studies are required to elucidate the underlying pathophysiology of dystonia in MSA.

Dystonia and parkinsonism

Parkinsonism and dystonia may coexist in a number of neurodegenerative, genetic, toxic, and metabolic disorders and as a result of structural lesions in the basal ganglia. Parkinson's disease (PD) and the 'Parkinson-plus' syndromes (PPS) account for the majority of patients with the parkinsonism-dystonia combination. Dystonia, particularly when it involves the foot, may be the presenting sign of PD or PPS and these disorders should be suspected when adults present with isolated foot dystonia. Young age, female gender, and long disease duration are risk factors for PD-related dystonia, but dystonia in patients with PD is usually related to levodopa therapy. The mechanism of dystonia in PD is not well understood and the management is often challenging because levodopa and other dopaminergic agents may either improve or worsen dystonia. Other therapeutic strategies include oral medications (baclofen, anticholinergics and benzodiazepines), local injections of botulinum toxin, intrathecal baclofen, and surgical lesions or high frequency stimulation of the thalamus, globus pallidus, or subthalamus.

Treatment of dystonic clenched fist with botulinum toxin

Fourteen patients with "dystonic clenched fist" (three with Corticobasal Ganglionic Degeneration, seven with Parkinson's disease, and four with Dystonic-Complex Regional Pain Syndrome) were treated with botulinum toxin A (BTXA, Dysport). The muscles involved were identified by the hand posture and EMG activity recorded at rest and during active and passive flexion/extension movements of the finger and wrist. EMG was useful in distinguishing between muscle contraction and underlying contractures and to determine the dosage of BTX. All patients had some degree of flexion at the proximal metacarpophalangeal joints and required injections into the lumbricals. The response in patients depended on the severity of the deformity and the degree of contracture. All patients had significant benefit to pain, with accompanying muscle relaxation, and palmar infection, when present, was eradicated. Four patients with Parkinson's disease and one patient with Dystonia-Complex Regional Pain Syndrome obtained functional benefit.