Blood pressure and heart rate in parkinsonian patients with and without wearing-off

Age as a risk factor for orthostatic hypotension induced by the levodopa challenge test in patients with Parkinson's disease: Results from a single-center trial

BACKGROUND

Hypotension can occur in patients receiving levodopa (L-dopa) treatment for parkinsonism. However, only few studies have focused on the characteristics of orthostatic hypotension (OH) induced by the L-dopa challenge test (LCT). This study aimed to investigate the characteristics and influencing factors of LCT-induced OH in a relatively large sample of patients with Parkinson's disease (PD).

METHODS

Seventy-eight patients with PD without a previous diagnosis of OH underwent the LCT. Blood pressure (BP) in the supine and standing positions was measured before and 2 hours after the LCT. If diagnosed with OH, the patients' BP was monitored again 3 hours after the LCT. The clinical features and demographics of the patients were analyzed.

RESULTS

Eight patients were diagnosed with OH 2 hours after the LCT (median dose of 375 mg L-dopa/benserazide; incidence = 10.3%). One patient without symptoms had OH 3 hours after the LCT. Compared with patients without OH, patients with OH had lower 1- and 3-minutes standing systolic BP and 1-minute standing diastolic BP at baseline and 2 hours after the LCT. Patients in the OH group were of older age (65.31 ± 4.17 years vs 59.74 ± 5.55years) and had lower Montreal Cognitive Assessment scores (17.5 vs 24) and higher L-dopa/benserazide levels (375 [250, 500] mg vs 250 [125, 500] mg). Older age markedly increased the odds of having LCT-induced OH (odds ratio, 1.451; 95% confidence interval, 1.055-1.995; P = .022).

CONCLUSIONS

LCT increased the odds of OH in non-OH PD, causing symptomatic OH in 10.3% of patients in our study, thereby raising safety concerns. Increase in age was observed to be a risk factor for LCT-induced OH in PD patients. A study with a larger sample size is warranted to confirm our results.

TRIAL REGISTRATION NUMBER

Clinical Trials Registry under ChiCTR2200055707.

DATE OF REGISTRATION

January 16, 2022.

An Individualized Multi-Modal Approach for Detection of Medication "Off" Episodes in Parkinson's Disease via Wearable Sensors

The primary treatment for Parkinson's disease (PD) is supplementation of levodopa (L-dopa). With disease progression, people may experience motor and non-motor fluctuations, whereby the PD symptoms return before the next dose of medication. Paradoxically, in order to prevent wearing-off, one must take the next dose while still feeling well, as the upcoming off episodes can be unpredictable. Waiting until feeling wearing-off and then taking the next dose of medication is a sub-optimal strategy, as the medication can take up to an hour to be absorbed. Ultimately, early detection of wearing-off before people are consciously aware would be ideal. Towards this goal, we examined whether or not a wearable sensor recording autonomic nervous system (ANS) activity could be used to predict wearing-off in people on L-dopa. We had PD subjects on L-dopa record a diary of their on/off status over 24 hours while wearing a wearable sensor (E4 wristband^®) that recorded ANS dynamics, including electrodermal activity (EDA), heart rate (HR), blood volume pulse (BVP), and skin temperature (TEMP). A joint empirical mode decomposition (EMD) / regression analysis was used to predict wearing-off (WO) time. When we used individually specific models assessed with cross-validation, we obtained > 90% correlation between the original OFF state logged by the patients and the reconstructed signal. However, a pooled model using the same combination of ASR measures across subjects was not statistically significant. This proof-of-principle study suggests that ANS dynamics can be used to assess the on/off phenomenon in people with PD taking L-dopa, but must be individually calibrated. More work is required to determine if individual wearing-off detection can take place before people become consciously aware of it.

A Digital Architecture for the Real-Time Tracking of Wearing off Phenomenon in Parkinson's Disease

Levodopa administration is currently the most common treatment to alleviate Parkinson's Disease (PD) symptoms. Nevertheless, prolonged use of Levodopa leads to a wearing-off (WO) phenomenon, causing symptoms to reappear. To build a personalized treatment plan aiming to manage PD and its symptoms effectively, there is a need for a technological system able to continuously and objectively assess the WO phenomenon during daily life. In this context, this paper proposes a WO tracker able to exploit neuromuscular data acquired by a dedicated wireless sensor network to discriminate between a Levodopa benefit phase and the reappearance of symptoms. The proposed architecture has been implemented on a heterogeneous computing platform, that statistically analyzes neural and muscular features to identify the best set of features to train the classifier model. Eight models among shallow and deep learning approaches are analyzed in terms of performance, timing and complexity metrics to identify the best inference engine. Experimental results on five subjects experiencing WO, showed that, in the best case, the proposed WO tracker can achieve an accuracy of ~84%, providing the inference in less than 41 ms. It is possible by employing a simple fully-connected neural network with 1 hidden layer and 32 units.

The hidden sister of motor fluctuations in Parkinson's disease: A review on nonmotor fluctuations

Only a few years after the introduction of levodopa, the first descriptions of motor fluctuations and dyskinesia related to dopaminergic therapy appeared. In PD, attention turned to their management, that had dampened the euphoria of the "levodopa miracle." It soon became clear that neuropsychiatric, autonomic, and sensory features also tend to develop fluctuations after chronic exposure to l-dopa. The diversity of fluctuating nonmotor symptoms, their largely subjective nature, coupled with a frequent lack of insight led to difficulties in identification and quantification. This may explain why, despite the high impact of nonmotor symptoms on patient autonomy and quality of life, evaluation of nonmotor fluctuations is not part of clinical routine. In view of the lack of specific validated assessment tools, detailed anamnesis should ideally be coupled with an evaluation in both ON and OFF drug conditions. The mechanisms of nonmotor fluctuations are not well understood. It is thought that they share dopaminergic presynaptic pharmacokinetic and postsynaptic pharmacodynamic mechanisms with the classical motor complications, but involve different neural pathways. Although symptoms fluctuate with dopaminergic treatment, serotonine and norepinephrine denervation, as well as interactions between neurotransmitter systems, probably contribute to their diversity. The lack of validated tools for assessment of these phenomena explains the almost complete absence of treatment studies. Management, largely resulting from expert opinion, includes psychiatric follow-up, nondopaminergic drugs, and advanced dopaminergic treatment, including drug delivery pumps and DBS. This review aims to provide a starting point for the understanding, diagnosis, and management of nonmotor fluctuations. © 2016 International Parkinson and Movement Disorder Society.

The Effect of Parkinson Drug Timing on Cardiovascular Response during Treadmill Exercise in a Person with Parkinson Disease and Freezing of Gait

PURPOSE

To examine the response of cerebral oxygenation during treadmill walking in a person with Parkinson disease (PD) who experiences freezing of gait (FOG) and to determine whether the oxygen response was related to the timing of his PD medication. Client Description: A 61-year-old man with PD performed two bouts of treadmill testing on the same day, during the on- and off-phases of his PD medication. Measures and Outcome: The client experienced two FOG episodes during the first testing session (on-phase with hypokinetic movement session). Cerebral oxygen response (measured by near-infrared spectroscopy) was stable until the FOG episodes occurred, at which point it decreased until the FOG episode was over. No electrocardiogram (ECG) changes or lightheadedness were noted; blood pressure (BP) remained stable. During the second exercise testing session (off-phase with dyskinetic movement session), the client did not experience any FOG episodes, and his cerebral oxygen response remained stable. Toward the end of the second testing session, he experienced lightheadedness and a drop in BP of approximately 30 mmHg, along with significant ST segment depression on his ECG.

IMPLICATIONS

Haemodynamic and cerebral oxygen changes occurred that were specific to the timing of the client's PD medication and to his FOG episodes. This case study shows a person with PD demonstrating decreased cerebral oxygenation during FOG, which may be based on his variable response to levodopa medication or may be attributable to as yet unidentified physiologic mechanisms.

Are dysautonomic and sensory symptoms present in early Parkinson's disease?

Parkinson's disease (PD) occurs with an annual incidence of 13/100.000, is slightly more frequent in men and is characterized by the motor symptoms tremor, rigidity, bradykinesia and postural instability. In addition, non-motor symptoms have been increasingly connected to the disease although already described in James Parkinson's 'Essay on the shaking palsy' from 1817. The motor symptoms in PD are related to the degeneration of dopaminergic cells in the substantia nigra (SN). These symptoms respond well to dopaminergic substitution. It is much more unclear whether non-motor symptoms like dysautonomia, insomnia, day-time sleepiness, fatigue, pain and neuropsychiatric symptoms respond to levodopa. Autonomic symptoms include dizziness because of orthostatic hypotension, constipation, nausea, voiding symptoms and increased sweating. Such symptoms as well as sensory symptoms like hyposmia and pain are very frequently reported in PD and seem to occur early in the disease process. Braak proposed a sequential model of neuropathology in PD starting with affection of the olfactory bulb and the autonomic innervation of the heart and gut. Affection of SN is seen from Braak stage 3, and limbic and cortical structures are affected in the later stages of the disease. Currently, the evidence for sensory and autonomic involvement in PD is reviewed with special focus on the early phase of the disease.

Nonmotor symptoms in Parkinson’s disease: the dark side of the moon

Nonmotor symptoms may appear during the course of Parkinson’s disease, complicating the advanced phase in particular, but are also common in the premotor phase of Parkinson’s disease. The appearance of nonmotor manifestations represents a milestone, determining a worse prognosis and lower quality of life; however, they are often misdiagnosed and untreated. The spectrum of nonmotor symptoms encompasses mood disorders, psychosis, dementia, sleep disorders, impulse-control disorders and autonomic dysfunctions. This article describes these nonmotor symptoms and their management.

Cardiac denervation occurs independent of orthostatic hypotension and impaired heart rate variability in Parkinson's disease

Patients with idiopathic Parkinson's disease (PD) have impaired sympathetically mediated neurocirculatory innervation. Here we analyzed the correlation between cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake, orthostatic hypotension and heart rate variability in treated patients with PD. Orthostatic hypotension (OH) as a hallmark of sympathetic neurocirculatory failure was found with a high prevalence in PD. PD is known to affect cardiac innervation, resulting in a suppressed heart rate variability and a postganglionic noradrenergic lesion. We measured continuous arterial blood pressure in rest and 70 degrees head-up tilt for at least 20 min, heart rate variability in the supine position, standing, deep respiration and Valsalva manoeuvre in 58 patients with PD (27 male, 31 female; mean age 71 years, mean PD duration 5.1 years, Hoehn and Yahr 3.1+/-0.8). Sympathovagal balance was estimated by the low-frequency (LF: 0.04-0.15Hz) and high-frequency bands (HF: 0.15-0.4Hz) ratio in the analysis of heart rate variability in each condition. Myocardial adrenergic function was analyzed by imaging MIBG using the single-photon emission computed tomography technique. MIBG uptake expressed as heart-to-mediastinum ratio was reduced in all PD patients (H/M-ratio: 1.14+/-0.16). We found no correlation between myocardial MIBG uptake and sympathovagal balance, blood pressure or other autonomic findings. The LF/HF ratio in tilt-table testing was significantly more reduced in PD with OH than without OH (2.18 vs. 1.49, p=0.022). MIBG uptake did not differ. It is concluded that scintigraphy with MIBG appears to be a highly sensitive and useful tool to demonstrate sympathetic postganglionic cardiac nerve disturbances. Loss of sympathetic innervation of the heart seems to occur early and independent of orthostatic hypotension, baroreflex failure and impaired heart rate variability in PD.