Diagnostic criteria for camptocormia in Parkinson's disease: A consensus-based proposal

INTRODUCTION

Camptocormia is defined as an involuntary, marked flexion of the thoracolumbar spine appearing during standing or walking and resolving in the supine position or when leaning against a wall. However, there is no established agreement on the minimum degree of forward flexion needed to diagnose camptocormia. Likewise, the current definition does not categorize camptocormia on the basis of the bending fulcrum.

METHODS

We performed a survey among movement disorders experts to identify camptocormia using images of patients with variable degrees and types of forward trunk flexion by fulcrum (upper and lower fulcra). We tested the subsequently generated diagnostic criteria in a sample of 131 consecutive patients referred for evaluation of postural abnormalities.

RESULTS

Experts reached full consensus on lower camptocormia (L1-Sacrum, hip flexion) with a bending angle ≥30° and upper camptocormia (C7 to T12-L1) with a bending angle ≥45°. This definition detected camptocormia in 9/131 consecutive PD patients (2 upper/7 lower) but excluded camptocormia in 71 patients considered to have camptocormia by the referring neurologist.

CONCLUSIONS

Camptocormia can be defined as "an involuntary flexion of the spine appearing during standing or walking and resolving in the supine position of at least 30° at the lumbar fulcrum (L1-Sacrum, hip flexion, i.e. lower camptocormia) and/or at least 45° at the thoracic fulcrum (C7 to T12-L1, i.e. upper camptocormia)". Strict criteria for camptocormia are met by 7% of patients with abnormal posture. The ascertainment of upper and lower camptocormia subtypes could improve the validity of epidemiological studies and assist future therapeutic trials.

Postural abnormalities in Asian and Caucasian Parkinson's disease patients: A multicenter study

INTRODUCTION

Postural abnormalities (PA) are disabling features of Parkinson's disease (PD). Indirect analyses suggested a higher prevalence of PA among Asian patients compared to Caucasian ones, but no direct comparisons have been performed so far.

METHODS

An international, multicenter, cross-sectional study was performed in 6 European and Asian movement disorders centers with the aim to clarify differences and similarities of prevalence and characteristics of PA in Asian vs. Caucasian PD patients. Axial PA, encompassing antecollis (AC), camptocormia (CC), and Pisa syndrome (PS), and appendicular PA (appPA) were systematically searched and analysed in consecutive patients.

RESULTS

88 (27%) of 326 PD patients had PA (29.1% in Asians and 24.3% in Caucasians, p: 0.331). Prevalence of axial PA was 23.6% in Asians and 24.3% in Caucasians (p = 0.886), in spite of a longer disease duration among Caucasians, but a longer PA duration among Asians. No differences in prevalence between AC, CC, and PS were found between the two ethnicities. The prevalence of appPA was higher in Asians (p = 0.036), but the regression analysis did not confirm a significant difference related to ethnicity. Considering the whole population, male gender (OR, 4.036; 95% CI, 1.926-8.456; p < 0.005), a longer disease duration (OR, 2.61; 95% CI, 1.024-6.653; p = 0.044), and a higher axial score (OR, 1.242; 95% CI, 1.122-1.375; p < 0.0005) were the factors associated with axial PA.

CONCLUSION

The prevalence of axial PA in PD patients is not influenced by ethnicity. However, Asian PD patients tend to develop PA earlier in the disease course, particularly AC.

Automated and accurate assessment for postural abnormalities in patients with Parkinson's disease based on Kinect and machine learning

Background

Automated and accurate assessment for postural abnormalities is necessary to monitor the clinical progress of Parkinson’s disease (PD). The combination of depth camera and machine learning makes this purpose possible.

Methods

Kinect was used to collect the postural images from 70 PD patients. The collected images were processed to extract three-dimensional body joints, which were then converted to two-dimensional body joints to obtain eight quantified coronal and sagittal features (F1-F8) of the trunk. The decision tree classifier was carried out over a data set established by the collected features and the corresponding doctors’ MDS-UPDRS-III 3.13 (the 13th item of the third part of Movement Disorder Society-Sponsored Revision of the Unified Parkinson’s Disease Rating Scale) scores. An objective function was implanted to further improve the human–machine consistency.

Results

The automated grading of postural abnormalities for PD patients was realized with only six selected features. The intraclass correlation coefficient (ICC) between the machine’s and doctors’ score was 0.940 (95%CI, 0.905–0.962), meaning the machine was highly consistent with the doctors’ judgement. Besides, the decision tree classifier performed outstandingly, reaching 90.0% of accuracy, 95.7% of specificity and 89.1% of sensitivity in rating postural severity.

Conclusions

We developed an intelligent evaluation system to provide accurate and automated assessment of trunk postural abnormalities in PD patients. This study demonstrates the practicability of our proposed method in the clinical scenario to help making the medical decision about PD.

Quantitative assessment of posture in healthy controls and patients with Parkinson's disease

INTRODUCTION

A stooped posture is a main clinical feature of Parkinson's disease (PD). The assessment of posture is important to measure treatment effects. The aim of this study was to investigate the reliability of a standardized postural rating tool, to calculate minimal detectable change scores and to assess the role of gender and age.

METHODS

Two independent raters assessed total camptocormia (TCC), upper camptocormia (UCC) and Pisa angles of 192 PD patients and 78 healthy controls (HC) with the free NeuroPostureApp©(http://www.neuroimaging.uni-kiel.de/NeuroPostureApp). Reliabilities and linear models were calculated for different effects. Three subgroups were defined based on two thresholds (mean+2SD of HC and PD): A) normal, B) presumed stooped/lateral bended posture and C) postural disorder.

RESULTS

Intraclass correlation coefficients ranged between 0.71 and 0.95 for the interrater and test-retest reliability of the three angles. The minimal detectable change values in the PD patients were 3.7°, 6.7° and 2.1° for the TCC, UCC and Pisa angles, respectively. Men had a more stooped posture than women (p < 0.05). Patients with PD had a worse posture than HC (p < 0.001) in all three angles. For the TCC angle, 39.1% of the patients had a normal posture (<17.4°), 47.9% a presumed stooped posture (>17.4°, <30.2°) and 6.3° had camptocormia (>30.2°).

CONCLUSIONS

The NeuroPostureApp© is reliable. Our results confirmed gender differences and the progression of postural deviation in PD patients with age and empirically support the ≥30° TCC angle as a defining criterium for camptocormia. Diagnostic criteria for UCC and Pisa syndrome should be further explored in future studies.

Gait and axial postural abnormalities correlations in Parkinson's disease: A multicenter quantitative study

INTRODUCTION

Gait and axial postural abnormalities (PA) are common and disabling symptoms of Parkinson's disease (PD). The interplay between them has been poorly explored.

METHODS

A standardized protocol encompassing videos and photos for posture and gait analysis of PD patients with a clinically defined PA (MDS-UPDRS-III item 3.13 > 0) was used in 6 movement disorder centers. A comprehensive evaluation was performed to clarify the association between gait performance and the presence and severity of PA.

RESULTS

225 PD patients were enrolled: 57 had severe PA, 149 mild PA, and 19 did not meet criteria for PA, according to a recent consensus agreement on PA definition. PD patients with severe PA were significantly older (p:0.001), with longer disease duration (p:0.007), worse MDS-UPDRS-II and -III scores and axial sub-scores (p < 0.0005), higher LEDD (p:0.002) and HY stage (p < 0.0005), and a significantly lower velocity (p < 0.001) and cadence (p:0.021), if compared to mild PA patients. The multiple regression analysis evaluating gait parameters and degrees of trunk/neck flexion showed that higher degrees of lumbar anterior trunk flexion were correlated with lower step length (OR -0.244; p:0.014) and lower velocity (OR -0.005; p:0.028).

CONCLUSIONS

Our results highlight the possible impact of severe anterior trunk flection on PD patients' gait, with a specific detrimental effect on gait velocity and step length. Personalized rehabilitation strategies should be elaborated based on the different features of PA, aiming to target a combined treatment of postural and specifically related gait pattern alterations.

The frequency and diagnostic accuracy of hand deformities in Parkinson's disease

Hand deformities are well-known abnormalities observed in patients with Parkinson's disease (PD). We determined the frequency and diagnostic accuracy of hand deformities in PD. We studied 44 consecutive patients with PD, 44 age- and gender-matched normal controls and 22 patients with essential tremor (ET). By means of photographs taken in both hands of all participants, the degree of metacarpophalangeal (MCP) joint flexion was quantified by software and by blinded evaluations using a semiquantitative scale from the radial aspect, we grouped hands into four grades. The presence of classical striatal hand deformity (CSHD), defined as MCP joint flexion, proximal interphalangeal joint extension and distal interphalangeal joint flexion was also evaluated. Patients with PD had a higher frequency of MCP joint flexion and CSHD compared to normal controls and patients with ET. Mean MCP joint flexion was higher in both hands in patients with PD: 20.8° vs. normal controls (3.3°-3.9°) and patients with ET (2.8°-6.3°), P = 0.001. Concordance between evaluators for MCP joint flexion was fair: κ = 0.34 (P < 0.001), but poor for CSHD: κ = 0.142-0.235 (P < 0.05). A right hand MCP joint flexion of 12.5° and left hand of 10.5°, showed similar sensitivity (0.70) and specificity (between 0.75 and 0.80) than any degree of MCP joint flexion for the diagnosis of PD. CSHD had a sensitivity (0.60-0.80) and specificity (0.78-0.98) for the diagnosis of PD. Hand deformities are commonly observed in patients with PD, they may aid in the diagnosis of PD when compared to normal controls and patients with ET.

Investigation of passive tone and viscoelasticity in neck muscles in pre-symptomatic neck flexion abnormality in Parkinson's disease: Observational study

BACKGROUND

Forward neck flexion (FNF) is a common postural abnormality in Parkinson's disease (PD), which disturbs the overall body alignment and can lead to more severe deformities through both central nervous system control and biomechanical compensation. The purpose of the current study was to investigate the biomechanical and viscoelastic properties of forward neck muscles related to FNF in individuals with PD, both with and without FNF, in comparison to age-matched individuals with normal posture.

METHODS

Hand-held myotonometry (Myoton Pro®) was conducted to determine the biomechanical and viscoelastic properties of the sternocleidomastoid and anterior scalene muscles of all thirty participants: individuals with PD and FNF (n = 10), individuals with PD without FNF (n = 10), and normal controls (n = 10).

RESULT

Individuals with PD, both with and without FNF, exhibited higher passive tone and muscle stiffness and lower elasticity, relaxation time, and creep in both muscles, particularly in the sternocleidomastoid, compared to age-matched normal controls. No significant differences in any muscle variables were found between the two PD groups.

CONCLUSION

These findings indicate that the biomechanical and viscoelastic properties of neck muscles are altered even in the presymptomatic stage of postural abnormalities in PD. This may provide potential evidence of underlying peripheral factors that involve postural deformities via proprioceptive disturbances and exacerbate rigidity in PD.

Two-minute standing endurance test for axial postural abnormalities in patients with Parkinson's disease

BACKGROUND

Photo-based measurement methods are used to assess axial postural abnormalities (PA) in Parkinson's disease (PD). However, they capture only moments in time. We developed the 2-minute standing endurance test (2 M-SET), which specifically captures temporal changes in posture, as a novel dynamic method for measuring axial PA in patients with PD.

RESEARCH QUESTION

This study aimed to verify the effectiveness and validity of the 2 M-SET for capturing temporal changes in axial PA in patients with PD.

METHODS

Twenty-eight patients with PD participated. The participants attempted to maintain an upright posture for 2 minutes during three tasks: standing, stepping in place, and walking. The rate of change in postural angle was recorded at 10-second intervals. Based on the results, the 2 M-SET was developed. Therapists evaluated the 2 M-SET using the NeuroPostureApp© to measure anterior trunk flexion (ATF) angles and lateral trunk flexion (LTF) angles at 0, 10, 30, 60, and 120 seconds. To assess reliability, the congruence between the measurements obtained by the therapists and those obtained using a three-dimensional motion-analysis system was examined. For validity, we assessed whether the ATF and LTF angles measured by the therapists could accurately capture postural changes at regular intervals over time.

RESULTS

The average postural changes over 2 minutes for the standing, stepping in place, and gait tasks were 59.2±83.5%, 37.6±30.7%, and 45.4±50.6%, respectively. The intraclass correlation coefficients showed high reliability, with values of 0.985 and 0.970 for the ATF and LTF angles, respectively.

SIGNIFICANCE

The results of our proposed 2 M-SET method, which uses temporal photo-based measurements to assess the patient's ability to maintain an upright standing position for 2 minutes, demonstrate the potential to capture temporal changes in axial PA.

DATA AVAILABILITY STATEMENT

The data supporting the findings of this study are available upon reasonable request and approval from the local ethics committee.

Effect of istradefylline on postural abnormalities in patients with Parkinson's disease: An association study of baseline postural angle measurements with changes in Unified Dystonia Rating Scale total score

In our previous study, istradefylline treatment in patients with Parkinson's disease (PD) improved postural abnormalities (PAs), as seen from a decrease in the mean Unified Dystonia Rating Scale (UDRS) total score from week 0 to week 24. A subgroup analysis based on baseline clinical characteristics investigated the association between improvement in the UDRS total score and istradefylline treatment. However, the association between an objective assessment of PAs and improvement in the UDRS total score is unclear. This ad hoc analysis investigated the association between improvement in the UDRS total score after istradefylline treatment and baseline trunk and neck angles, objective assessments of PAs, measured from patients' photographs taken in the previous study. The patients (n = 31) were stratified into groups based on the trunk forward flexion angle (TFFA), trunk lateral flexion angle (TLFA), and neck flexion angle (NFA) values at baseline. From week 0 to week 24, significant improvements in the UDRS total score were found in median percent change (-8.33% [interquartile range: -43.97, 0.00], P = 0.039) in patients with equal to or above the median TFFA values, and in median change (-‍1.50 [-9.25, 0.00], P = 0.015) and median percent change (-13.33% [-50.47, 0.00], P = 0.009) in patients with equal to or above the median TLFA values. Patients with more advanced PAs showed more consistent improvements in the UDRS total score with istradefylline. Baseline TFFA and TLFA values, which are objective values, may be useful to assess the istradefylline effectiveness in patients with PD and PAs.

Current status of pelvic lateral shift in patients with Parkinson's disease and its relation to lateral trunk flexion

Objectives

A lack of standardized methods for evaluating postural abnormalities hinders treatment progress. The role of pelvic lateral shift (PLS) in patients with Parkinson's disease (PwP) exhibiting lateral trunk flexion (LTF) remains unclear. We hypothesized that PLS is related to LTF and investigated its characteristics and relationship to LTF angle.

Methods

PwP attending outpatient rehabilitation (March 2018-March 2023) were assessed using still images. PLS direction, its relationship with LTF angle, and LTF angle by PLS side were analysed.

Results

Among 158 patients, PLS was contralateral in 80 (50.6%), ipsilateral in 43 (27.2%), and absent in 35 (22.2%). In contralateral PLS, but not ipsilateral, PLS angle correlated with LTF angle (r=0.48, p<0.001). LTF angle was greater in contralateral (8.5±9.6°) than ipsilateral shift (2.8±4.2°, p<0.001).

Conclusions

Because of the positive relationship between LTF angle and contralateral shift angle, evaluation criteria that include PLS are needed for PwP with LTF.

Spinal cord stimulation for postural abnormalities in Parkinson's disease: 1-year prospective pilot study

BACKGROUND

Postural abnormalities (PA) are common in the advanced stages of Parkinson's disease (PD), but effective therapies are lacking. A few studies suggested that spinal cord stimulation (SCS) could be a potential therapy whereas its effect is still uncertain. We aimed to investigate whether SCS had potential for benefiting PD patients with PA.

METHODS

T8-12 SCS was operated on six PD patients with PA and all patients were followed for one year. Evaluations were made before and after SCS. Moreover, three patients were tested separately with SCS on-state and off-state to confirm the efficacy of SCS.

RESULTS

Improvements in lateral trunk flexion degree, anterior thoracolumbar flexion degree and motor function were found after SCS. The improvements diminished while SCS was turned off.

CONCLUSIONS

Lower thoracic SCS may be effective for improving PA in PD patients, but further studies are needed to confirm this conclusion.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1900024326, Registered on 6th July 2019; https://www.chictr.org.cn/showproj.aspx?proj=40835 .

Gait Instability and Compensatory Mechanisms in Parkinson's Disease Patients With Camptocormia: An Exploratory Study

OBJECTIVE

Camptocormia contributes to vertical gait instability and, at times, may also lead to forward instability in experimental settings in Parkinson's disease (PD) patients. However, these aspects, along with compensatory mechanisms, remain largely unexplored. This study comprehensively investigated gait instability and compensatory strategies in PD patients with camptocormia (PD+CC).

METHODS

Ten PD+CC patients, 30 without camptocormia (PD-CC), and 27 healthy controls (HCs) participated. Self-paced gait tasks were analyzed using three-dimensional motion capture systems to assess gait stability as well as spatiotemporal and kinematic parameters. Unique cases with pronounced forward gait stability or instability were first identified, followed by group comparisons. Correlation analysis was performed to examine associations between trunk flexion angles (lower/upper) and gait parameters. The significance level was set at 0.05.

RESULTS

Excluding one unique case, the PD+CC group presented a significantly lower vertical center of mass (COM) position (p=0.019) increased mediolateral COM velocity (p=0.004) and step width (p=0.013), compared to the PD-CC group. Both PD groups presented greater anterior‒posterior margins of stability than did the HCs (p<0.001). Significant correlations were found between lower/upper trunk flexion angles and a lower vertical COM position (r=-0.690/-0.332), as well as increased mediolateral COM velocity (r=0.374/0.446) and step width (r=0.580/0.474).

CONCLUSION

Most PD+CC patients presented vertical gait instability, increased fall risk, and adopted compensatory strategies involving greater lateral COM shift and a wider base of support, with these trends intensifying as trunk flexion angles increased. These findings may guide targeted interventions for gait instability in PD+CC patients.