Camptocormia, head drop and other bent spine syndromes: heterogeneous etiology and pathogenesis of Parkinsonian deformities

Botulinum Toxin for Axial Postural Abnormalities in Parkinson's Disease: A Systematic Review

Axial postural abnormalities (APAs), characterized by their frequency, disabling nature, and resistance to pharmacological treatments, significantly impact Parkinson's disease and atypical Parkinsonism patients. Despite advancements in diagnosing, assessing, and understanding their pathophysiology, managing these complications remains a significant challenge. Often underestimated by healthcare professionals, these disturbances can exacerbate disability. This systematic review assesses botulinum toxin treatments' effectiveness, alone and with rehabilitation, in addressing APAs in Parkinson's disease, utilizing MEDLINE (PubMed), Web of Science, and SCOPUS databases for source material. Of the 1087 records retrieved, 16 met the selection criteria. Most research has focused on botulinum toxin (BoNT) as the primary treatment for camptocormia and Pisa syndrome, utilizing mostly observational methods. Despite dose and injection site variations, a common strategy was using electromyography-guided injections, occasionally enhanced with ultrasound. Patients with Pisa syndrome notably saw consistent improvements in APAs and pain. However, studies on the combined effects of botulinum toxin and rehabilitation are limited, and antecollis is significantly under-researched. These findings recommend precise BoNT injections into hyperactive muscles in well-selected patients by skilled clinicians, avoiding compensatory muscles, and underscore the necessity of early rehabilitation. Rehabilitation is crucial in a multidisciplinary approach to managing APAs, highlighting the importance of a multidisciplinary team of experts.

A systematic review and meta-analysis of respiratory dysfunction in Parkinson's disease

INTRODUCTION

Respiratory dysfunction in Parkinson's disease (PD) is common and associated with increased hospital admission and mortality rates. Central and peripheral mechanisms have been proposed in PD. To date no systematic review identifies the extent and type of respiratory impairments in PD compared with healthy controls.

METHODS

PubMed, EMBASE, CINAHL, Web of Science, Pedro, MEDLINE, Cochrane Library and OpenGrey were searched from inception to December 2021 to identify case-control studies reporting respiratory measures in PD and matched controls.

RESULTS

Thirty-nine studies met inclusion criteria, the majority with low risk of bias across Risk of Bias Assessment tool for Non-randomized Studies (RoBANS) domains. Data permitted pooled analysis for 26 distinct respiratory measures. High-to-moderate certainty evidence of impairment in PD was identified for vital capacity (standardised mean difference [SMD] 0.75; 95% CI 0.45-1.05; p < 0.00001; I2  = 10%), total chest wall volume (SMD 0.38; 95% CI 0.09-0.68; p = 0.01; I2  = 0%), maximum inspiratory pressure (SMD 0.91; 95% CI 0.64-1.19; p < 0.00001; I2  = 43%) and sniff nasal inspiratory pressure (SMD 0.58; 95% CI 0.30-0.87; p < 0.00001; I2  = 0%). Sensitivity analysis provided high-moderate certainty evidence of impairment for forced vital capacity and forced expiratory volume in 1 s during medication ON phases and increased respiratory rate during OFF phases. Lower certainty evidence identified impairments in PD for maximum expiratory pressure, tidal volume, maximum voluntary ventilation and peak cough flow.

CONCLUSIONS

Strong evidence supports a restrictive pattern with inspiratory muscle weakness in PD compared with healthy controls. Limited data for central impairment were identified with inconclusive findings.

Axial posture disorders in Parkinson's disease: Clinical correlates and future treatment directions1

BACKGROUND

Postural disorders are frequently observed in Parkinson's disease (PD). The underlying mechanisms that cause postural disorders are not fully understood and the majority of these disorders have no response to antiparkinsonian treatments. These disabling conditions require further investigation to better understand the underlying mechanisms in order to develop effective treatments.

OBJECTIVE

The aim of this study was to investigate the frequency of axial postural disorders in PD and to determine the associated clinical risk factors.

METHODS

In this single-center clinical trial, the data of PD patients were reviewed retrospectively. The frequencies of postural disorders were determined, and the demographic clinical characteristics of the patients were compared.

RESULTS

The records of 127 patients with idiopathic PD were analyzed. Axial posture disorders were found in 42.6% of patients. Patients with axial posture disorders were older when the disease onset was detected, amongst these patients the condition was also longer lasting. The mean levodopa dose was higher in the patients with posture disorders. The initial symptom was bradykinesia and the Hoehn and Yahr's score was ⩾ 3 in the majority of the patients with posture disorder. Additionally, constipation, hallucinations, postural instability, and falls were significantly more common in patients with posture disorders.

CONCLUSION

Posture disorders were observed in nearly half of PD patients and were more frequently observed in patients with an advanced condition. In addition, our investigation has found that it is crucial to follow up with patients who present with bradykinesia for the development of postural disorder.

Chronic Respiratory Diseases and Neurodegenerative Disorders: A Primer for the Practicing Clinician

Chronic respiratory disorders represent a world epidemic. Their incidence and prevalence in the world population is increasing, and especially among elderly subjects, they are commonly associated with other pathologies, often generating a status of high clinical complexity. Neurology, internal medicine, and pneumology specialists should be aware of the common background of these disorders in order to treat correctly the patient's comorbid state and optimize the treatment considering potential overlaps. In this review, we aimed to focus on the relationships between chronic respiratory disorders and chronic neurodegenerative diseases at different levels; we review the shared risk factors and the interactions between disorders, the indications to explore respiratory function in neurodegenerative diseases, pathology-pathology and drug-pathology interactions in patients affected by both chronic neurologic and respiratory diseases.

Dystonia and Parkinson's disease: What is the relationship?

Dystonia and Parkinson's disease are closely linked disorders sharing many pathophysiological overlaps. Dystonia can be seen in 30% or more of the patients suffering with PD and sometimes can precede the overt parkinsonism. The response of early dystonia to the introduction of dopamine replacement therapy (levodopa, dopamine agonists) is variable; dystonia commonly occurs in PD patients following levodopa initiation. Similarly, parkinsonism is commonly seen in patients with mutations in various DYT genes including those involved in the dopamine synthesis pathway. Pharmacological blockade of dopamine receptors can cause both tardive dystonia and parkinsonism and these movement disorders syndromes can occur in many other neurodegenerative, genetic, toxic and metabolic diseases. Pallidotomy in the past and currently deep brain stimulation largely involving the GPi are effective treatment options for both dystonia and parkinsonism. However, the physiological mechanisms underlying the response of these two different movement disorder syndromes are poorly understood. Interestingly, DBS for PD can cause dystonia such as blepharospasm and bilateral pallidal DBS for dystonia can result in features of parkinsonism. Advances in our understanding of these responses may provide better explanations for the relationship between dystonia and Parkinson's disease.

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.

The effect of comprehensive physiotherapy-based rehabilitation on stooped posture in Parkinson's disease

[Purpose] The effect of physiotherapy on stooped posture in Parkinson's disease patients remains to be clarified. Therefore, the purpose of this study was to investigate whether comprehensive physiotherapy-based rehabilitation can improve stooped posture in Parkinson's disease patients. [Participants and Methods] The participants were Parkinson's disease patients with stooped posture. Outpatients were assigned to the control group and inpatients to the postural rehabilitation group. The outcomes measured were trunk bending angle, lumbar lordosis, and thoracic kyphosis. Each group was assessed at baseline and 1 month later. [Results] Of 22 participants identified, 20 were included, with 10 participants in the postural rehabilitation group and 10 in the control group. The age in the postural rehabilitation group was significantly greater than that in the control group, while other parameters were comparable in both groups. After the month-long intervention, the trunk bending angle and lumbar lordosis were significantly improved in the postural rehabilitation group compared to the control group. [Conclusion] The results showed improvement in stooped posture in the postural rehabilitation group as compared to the control group. Furthermore, improvement of lumbar lordosis accompanied improvement of stooped posture. These findings suggest that comprehensive physiotherapy-based rehabilitation may improve stooped posture in Parkinson's disease patients.

An update on new and unique uses of botulinum toxin in movement disorders

The therapeutic applications of botulinum toxin (BoNT) have grown manifold since its initial approval in 1989 by the US Food and Drug Administration (FDA) for the treatment of strabismus, blepharospasm, and other facial spasms. Although it is the most potent biologic toxin known to man, long-term studies have established its safety in the treatment of a variety of neurologic and non-neurologic disorders. This review focuses on some novel and uncommon uses of BoNT in the treatment of movement disorders, such as oromandibular dystonia, including bruxism, anterocollis, camptocormia, tremor, tics, tardive and levodopa-induced dyskinesia, and restless legs syndrome. Despite a paucity of randomized controlled trials and lack of FDA approval for these movement disorders, there is growing body of evidence that BoNT provides benefit to patients with these hyperkinetic movement disorders and that BoNT is a safe treatment when used by clinicians skilled in the administration of the drug for these conditions.

[What would you do with an adult patient who consults due to head muscle weakness and has dropped head?]

The dropped head syndrome, whether due to muscle weakness, rigidity, or ankylosis, is not uncommon in the elderly. It is characterised by a "chin-on-chest" reducible kyphosis, which is secondary to head muscle debility. It may be associated with a neuromuscular group of diseases such as polymyositis, chronic Inflammatory demyelinating polyneuropathy, myasthenia gravis, amyotrophic lateral sclerosis, and inclusion-body myositis. Some cases associated with hypothyroidism and hyperparathyroidism have also been described. Prognosis without treatment is poor. Therefore, familiarity with this condition, together with a complete anamnesis and physical examination, should lead us to the clinical suspicion and selection of the appropriate complementary tests. In this article, a case of dropped head syndrome is reported, as well as an algorithm for its diagnosis.

Drug-Induced Dyskinesia, Part 1: Treatment of Levodopa-Induced Dyskinesia

Dyskinesias encompass a variety of different hyperkinetic phenomenologies, particularly chorea, dystonia, stereotypies, and akathisia. Levodopa-induced dyskinesia (LID) is one of the main types of drug-induced dyskinesia, occurring in patients with Parkinson's disease (PD) who have been treated with levodopa for long time, but this side effect may be encountered even within a few weeks or months after initiation of levodopa therapy. Based on the temporal pattern in relationship to levodopa dosing, LIDs are divided into "peak-dose dyskinesia," "diphasic dyskinesia," and "wearing off" or "off-period" dyskinesia, of which peak-dose dyskinesia is the most common, followed by off-period, and then diphasic dyskinesia. Treatment strategy includes identifying the kind of dyskinesia and tailoring treatment accordingly. Peak-dose dyskinesia is treated mainly by reducing individual doses of levodopa and adding amantadine and dopamine agonists, whereas off-period dystonia often responds to baclofen and botulinum toxin injections. Diphasic dyskinesias, occurring particularly in patients with young-onset PD, are the most difficult to treat. While fractionation of levodopa dosage is the most frequently utilized strategy, many patients require deep brain stimulation to control their troublesome motor fluctuations and LIDs. A variety of emerging (experimental) drugs currently in development promise to provide better control of LIDs and other levodopa-related complications in the near future.

Subthalamic nucleus stimulation improves Parkinson's disease-associated camptocormia in parallel to its preoperative levodopa responsiveness

OBJECTIVE

The aim of this work was to identify factors predictive of postoperative improvement of camptocormia in patients with Parkinson's disease (PD) treated by subthalamic nucleus (STN) stimulation.

BACKGROUND

Camptocormia, one of the most disabling features of PD, often responds poorly to medical therapies. The reported effects of deep brain stimulation on PD-associated camptocormia vary, and preoperative characteristics affecting the surgical outcome remain unclear.

METHODS

We evaluated 17 patients with camptocormia whose preoperative off-medication thoracolumbar angle exceeded 45°. We used photographs to measure their thoracolumbar angle preoperatively, 3 months after surgery, and at the last follow-up (mean 36.5 months postoperatively) in status on-medication and off-medication. The patient age, duration of PD and camptocormia, daily medications, Unified Parkinson's Disease Rating Scale (UPDRS) subscores and the Schwab-England activity of daily living scale (S-E) were also recorded. Univariate analysis was performed to identify factors predictive of the postoperative improvement of camptocormia.

RESULTS

STN stimulation significantly improved the UPDRS subscores and S-E, and resulted in a reduction of daily medications 3 months post-treatment. The preoperative thoracolumbar angle (mean±SD) in status off-medication (84.0±29.5°) was significantly ameliorated 3 months postoperatively (49.8±29.3°) and at the last follow-up (54.8±28.3°). There was no correlation between the postoperative camptocormia improvement rate and preoperative parameters other than the duration and severity of camptocormia and the levodopa responsiveness of the thoracolumbar angle. Symptom duration negatively affected levodopa responsiveness.

CONCLUSIONS

STN stimulation improves PD-associated camptocormia in parallel with preoperative levodopa responsiveness. Long symptom duration interferes with levodopa responsiveness.

Neck Pain and Cervical Dystonia: Treatment Outcomes from CD PROBE (Cervical Dystonia Patient Registry for Observation of OnabotulinumtoxinA Efficacy)

BACKGROUND

Pain is a prevailing feature of cervical dystonia (CD), the most common form of focal dystonia. This analysis examined pain relief after onabotulinumtoxinA treatment in CD subjects with moderate/severe pain from the Cervical Dystonia Patient Registry for Observation of OnabotulinumtoxinA Efficacy (CD PROBE).

METHODS

CD PROBE was a prospective, multicenter, observational registry of CD subjects who were naïve to botulinum toxin (BoNT), new to physician, or had not received BoNT within ≥ 16 weeks if in a clinical trial. Subjects were eligible for 3 treatments, with variable session intervals. Descriptive and inferential statistics were utilized to evaluate the change in pain scores in the population with moderate/severe neck pain at baseline (Pain Numeric Rating Scale [PNRS] score 4 to 10).

RESULTS

Of 1046 enrolled, 733 (70.7%) had moderate/severe neck pain at baseline. Postinjection pain questionnaire responses 4 to 6 weeks after each of the 3 treatments revealed that a majority of subjects (67.1%, 72.4%, and 76.4%) reported pain relief; mean time to pain relief was 7.1, 7.4, and 7.6 days. All pain scales showed significant improvements from baseline to final visit (all P < 0.0001): PNRS, mean 6.6 to 3.8; CD Impact Profile-58 Pain and Discomfort subscale, mean 78.7 to 56.5; and Toronto Western Spasmodic Torticollis Rating Scale Pain subscale, mean 12.6 to 8.5. Multivariable regression models showed that initial pain score significantly contributed to the final pain score for all scales.

CONCLUSION

Results from this real-world clinical registry indicate that a majority of CD subjects with moderate/severe neck pain experience significant relief following onabotulinumtoxinA treatment.

Camptocormia in Parkinson's disease: definition, epidemiology, pathogenesis and treatment modalities

Camptocormia is an axial postural deformity characterised by abnormal thoracolumbar spinal flexion. The symptom usually presents while standing, walking or exercising and is alleviated while sitting, lying in a recumbent position, standing against a wall or using walking support. There is no consensus on the degree of thoracolumbar flexion to define camptocormia. However, most authors usually use an arbitrary number of at least 45° flexion of the thoracolumbar spine when the individual is standing or walking. Aetiologies of camptocormia are heterogeneous, and Parkinson's disease (PD) is one of its many causes. The prevalence of camptocormia in PD ranges from 3% to 18%. Central and peripheral mechanisms might both contribute to its pathogenesis. Although there is no established consensus for treatment of camptocormia in PD, there are non-pharmacological, pharmacological and surgical approaches that can be used.

An ¹⁸F-FDG PET study of cervical muscle in parkinsonian anterocollis

The underlying etiology of parkinsonian anterocollis has been the subject of recent debate. The purpose of this study is to test the hypothesis that anterocollis in parkinsonian syndromes is associated with dystonia of the deep cervical flexors (longus colli and capitis). Eight patients with anterocollis, six in the setting of parkinsonism and two primary cervical dystonia control subjects with anterocollis underwent prospective structured clinical evaluations (interview, examination and rating scales), systematic electromyography of the cervical extensor musculature and (18)F-FDG PET/CT studies of cervical muscles to examine evidence of hypermetabolism or overactivity of deep cervical flexors. Subjects with parkinsonian anterocollis were found to have hypermetabolism of the extensor and sub-occipital muscles but not in the cervical flexors (superficial or deep). EMG abnormalities were observed in all evaluated patients, but only one patient was definitely myopathic. Meanwhile, both dystonia controls exhibited hypermetabolism of cervical flexors (including the longus colli). In conclusion, we were able to demonstrate hypermetabolism of superficial and deep cervical flexors with muscle (18)F-FDG PET/CT in dystonic anterocollis patients, but not in parkinsonian anterocollis patients. The hypermetabolic changes seen in parkinsonian anterocollis patients in posterior muscles may be compensatory. Alternative explanations for anterocollis include myopathy of the cervical extensors, or unbalanced rigidity of the cervical flexors, but this remains to be proven.

Subthalamotomy in the treatment of Parkinson's disease: clinical aspects and mechanisms of action

Parkinson's disease (PD) is a neurodegenerative condition that can be pharmacologically treated with levodopa. However, important motor and nonmotor symptoms appear with its long-term use. The subthalamic nucleus (STN) is known to be involved in the pathophysiology of PD and to contribute to levodopa-induced complications. Surgery is considered in patients who have advanced PD that is refractory to pharmacotherapy and who display disabling dyskinesia. Deep brain stimulation of the STN is currently the main surgical procedure for PD, but lesioning is still performed. This review covers the clinical aspects and complications of subthalamotomy as one of the lesion-based options for PD patients with levodopa-induced dyskinesias. Moreover, the authors discuss the possible effects of subthalamic lesioning.

Descriptive epidemiology of cervical dystonia

Background

Cervical dystonia (CD), the most common form of adult-onset focal dystonia, has a heterogeneous clinical presentation with variable clinical features, leading to difficulties and delays in diagnosis. Owing to the lack of reviews specifically focusing on the frequency of primary CD in the general population, we performed a systematic literature search to examine its prevalence/incidence and analyze methodological differences among studies.

Methods

We performed a systematic literature search to examine the prevalence data of primary focal CD. Sixteen articles met our methodological criteria. Because the reported prevalence estimates were found to vary widely across studies, we analyzed methodological differences and other factors to determine whether true differences exist in prevalence rates among geographic areas (and by gender and age distributions), as well as to facilitate recommendations for future studies.

Results

Prevalence estimates ranged from 20–4,100 cases/million. Generally, studies that relied on service-based and record-linkage system data likely underestimated the prevalence of CD, whereas population-based studies suffered from over-ascertainment. The more methodologically robust studies yielded a range of estimates of 28–183 cases/million. Despite the varying prevalence estimates, an approximate 2:1 female:male ratio was consistent among many studies. Three studies estimated incidence, ranging from 8–12 cases/million person-years.

Discussion

Although several studies have attempted to estimate the prevalence and incidence of CD, there is a need for additional well-designed epidemiological studies on primary CD that include large populations; use defined CD diagnostic criteria; and stratify for factors such as age, gender, and ethnicity.

Review: management of Parkinson's disease

Parkinson's disease (PD) is one of the most frequent neurological diseases. Despite the modern imaging and nuclear techniques which help to diagnose it in a very early stage and lead to a better discrimination of similar diseases, PD has remained a clinical diagnosis. The increasing number of available treatment options makes the disease management often complicated even when the presence of PD seems undoubted. In addition, nonmotor symptoms and side effects of some therapies constitute some pitfalls already in the preclinical state or at the beginnings of the disease, especially with the progressive effect on patients. Therefore, this review aimed to summarize study results and depict recommended medical treatments for the most common motor and nonmotor symptoms in PD. Additionally, emerging new therapeutic options such as continuous pump therapies, eg, with apomorphine or parenteral levodopa, or the implantation of electrodes for deep brain stimulation were also considered.

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.

Anterocollis and camptocormia in parkinsonism: a current assessment

Postural deformities in parkinsonian syndromes are well recognized, but poorly understood and largely refractory to available therapies. In recent times a number of hypotheses have been proposed to explain the underlying etiology of anterocollis and camptocormia, but currently there is no consensus. As these conditions are more precisely characterized we begin to uncover that this is a heterogeneous and evolving phenomenon. These conditions bring to light the inadequacies of our current tools to study biomechanics of posture, neuromuscular disorders, and dystonic muscular contractions. The development of objective, accurate tools to directly study and measure the severity of these postural disorders will allow for further understanding of the pathophysiology, the development of novel therapeutics, and adequate clinical trial design.

Myofibrillar disorganization characterizes myopathy of camptocormia in Parkinson's disease

Camptocormia is a highly disabling syndrome that occurs in various diseases but is particularly associated with Parkinson's disease (PD). Although first described nearly 200 years ago, the morphological changes associated with camptocormia are still under debate and the pathophysiology is unknown. We analyzed paraspinal muscle biopsies of 14 PD patients with camptocormia and compared the findings to sex-matched postmortem controls of comparable age to exclude biopsy site-specific changes. Camptocormia in PD showed a consistent lesion pattern composed of myopathic changes with type-1 fiber hypertrophy, loss of type-2 fibers, loss of oxidative enzyme activity, and acid phosphatase reactivity of lesions. Ultrastructurally, myofibrillar disorganization and Z-band streaming up to electron-dense patches/plaques were seen in the lesions. No aberrant protein aggregation, signs of myositis or mitochondriopathy were found, but the mitochondrial content of paraspinal muscles in patients and controls was markedly higher than known from limb biopsies. Additionally, we were able to demonstrate a link between the severity of the clinical syndrome and the degree of the myopathic changes. Because of the consistent lesion pattern, we propose criteria for the diagnosis of camptocormia in PD from muscle biopsies. The morphological changes show obvious parallels to the muscle pathology of experimental tenotomy reported in the 1970s, which depend on an intact innervation and do not occur after interruption of the myotactic reflexes. A dysregulation of the proprioception could be part of the pathogenesis of camptocormia in Parkinson's disease, particularly in view of the clinical symptoms of rigidity and loss of muscle strength.

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.