The novelty of this pilot study is the preliminary-assessed utility of the proposed comprehensive telemedicine solution for real-time home monitoring of vital signs in patients with Parkinson’s disease and orthostatic hypotension. Compared to other studies [20, 23], using home BP holter recordings, a remote real-time monitoring system, could increase patient’s safety and compliance, as well as data reliability.
According to the results of this pilot study, the application of the proposed telemonitoring system in this particular subset of patients reveals relevant information with crucial clinical and health care management implications. e-Health solutions for PD patients so far have been mostly applied to investigate PD motor aspects [19, 24, 25], such as ON-OFF fluctuation, postural stability, and gait disturbances, but only few studies have focused on real-time monitoring of autonomic impairment .
COVID-19 pandemic increased dramatically the need for telemonitoring systems in order to manage chronically ill patients during lockdown period  and created the opportunity to extend the fields of applications of already available devices on different pathologic conditions, as we performed in our experience.
OH represents a major source of disability and an independent risk factor for mortality in elderly and in the PD population, leading to postural instability, gait impairment, and repetitive falls with consequent increase of accesses to Emergency Room (ER) for head trauma and fractures . An early detection and a correct management of this dysautonomic complication are thus of paramount importance in reducing the need for access to hospital facilities. Noteworthy, 2 out of 8 patients in our study were reporting symptoms suggestive of OH, without a formal diagnosis; in these patients, the telemonitoring system allowed the clinician to detect OH episodes and associated symptoms and to perform further ANS testing to confirm the OH diagnosis. The management of OH in PD population is sometimes very challenging, considering also the associated hypotensive effect of dopaminergic drugs, increasing the overall autonomic symptoms burden . OH can occur with or without symptoms, so despite its frequency, this phenomenon is frequently under-recognized. We found that thirty-five out of 65 (53.8%) OH episodes were reported as asymptomatic, with a higher rate in the postprandial (60%) and in the afternoon (63.2%) recordings compared to morning measurements (38.1%) that were mostly accompanied by symptoms. Moreover, the lower absolute SBP and DBP mean values (both in supine and standing positions) were recorded during postprandial and afternoon measurements, while higher absolute values of both SBP and DBP were found in the morning after awakening. These findings may be due to the physiological circadian rhythm involving the activation of sympathetic nervous system and to a not negligible impact of morning hypertension in 3 of our patients.
As a main finding, our analysis comparing symptomatic versus asymptomatic episodes showed lower SBP and DBP mean values (in standing position) together with higher SBP and DBP drops when symptoms were present.
These data are in agreement with literature sustaining that the presence of symptoms seems to depend mostly on absolute BP value in the standing position rather than on the magnitude of BP drop [29, 30].
Supporting this notion, a study with 210 patients with PD reported that standing mean BP < 75 mmHg predicted presence of OH symptoms with a sensitivity of 97% and a specificity of 98%. On the other hand, only 31% of patients with OH reported OH symptoms and these diagnostic criteria predicted presence of symptoms with a sensitivity of 92% and a specificity of 58% .
Moreover, another study with 205 patients with exaggerated SBP reduction (> 60 mmHg) during head up tilt test suggested that 33% of patients were asymptomatic, whereas the magnitude of SBP drop was similar in symptomatic and asymptomatic patients . On the contrary, our results showed the presence of a significant difference of both systolic and diastolic blood pressure drops in symptomatic versus asymptomatic OH episodes, suggesting that also the magnitude of BP drop could affect the presence of orthostatic symptoms. These data highlights the crucial clinical implications of using a home telemonitoring system in PD patients with dysautonomia to improve OH detection and management, especially taking into account the high rate of totally asymptomatic episodes and their potential clinical complications.
Patients with PD represent a higher risk category for OH, considering all the other possible concomitant risk factors such as medication use, comorbidities, reduced physical activity, and dehydration. This scenario is mandatory to consider the prognostic role of OH: about this topic, numerous large prospective studies have demonstrated a relationship between OH and adverse cardiovascular (CV) and non-CV outcomes such as cognitive decline, decreased physical functioning, risk of falls, and late-life depression, confirming the importance of an early detection of this phenomena, even when asymptomatic, in this at risk population .
In our study, 65 total episodes of OH were recorded during the whole monitoring. OH episodes occurred in a higher rate after meal (38.5%) and in the morning (32.3%), followed by afternoon recordings (29.2%).
Orthostatic hypotension is believed to occur more frequently in the morning after awakening and after large meals (postprandial OH). From a pathophysiological point of view, volume depletion due to increased nocturnal diuresis induced by supine hypertension is the proposed mechanism at the bases of morning OH episodes . On the other hand, the venous pooling occurring after large meals is probably responsible of postprandial OH, together with a possible contribution of insulin-mediated vasodilatation . According to our findings, a BP monitoring focusing on potential situations of orthostatic stress (such as early hours in the morning after awakening) or possible triggers (meals, physical activity) is crucial to increase the possibility to capture OH episodes which may remain otherwise silent and unrecognized, providing an accurate assessment and management of nOH phenomena.
Furthermore, HR has also been assessed in our patients, showing that in 87.7% of OH episodes was observed a concomitant increase of HR lower than 15 bpm. Our findings lead support to the concept that HR evaluation is important to perform in the context of nOH assessment, since a failure of the chronotropic compensatory response (< 10–15 bpm) is supportive of autonomic impairment and may represent a practical tool to detect nOH . As previously reported in the “Results” section, no alterations in temperature and oxygen saturation were recorded. The inclusion of these further parameters in the monitoring system might have important implications in the context of COVID-19 pandemic emergency, especially in a frailer population such as Parkinsonian patients and could also be useful to minimize confounding factors regarding OH clinical manifestation.
When symptoms were present, patients mostly reported a sensation of dizziness or lightheadedness and fatigue when standing followed by feeling faint, confusion, and difficulty walking. Symptoms presented as a constant complaint like in the case of fatigue or multiple times a day, triggered by positional changes from sit to standing or during longer periods of orthostatism.
The assessment and prompt management of symptoms are fundamental because symptomatic burden can lead to immobility and reduced level of functional independence, which in turn further worsen the severity of OH . The impact extent of symptoms on daily life activities has been also quantified with a self-rating scale of severity, confirming the striking negative effect of OH on daily life activities and functional independence in the majority of patients. Interestingly, falls caused by OH symptoms (at least one in the previous year) were reported by 3 out of 8 patients (37.5%) in our sample, with a mean of 2.7 falls. These data suggest that the implementation of an e-Health system in this population may have a great impact on reduction of hospital admissions due to falls and related traumas.
On the other hand, the presence of OH symptoms alone may not represent an accurate indicator of tissue hypoperfusion especially in patients with PD. Symptoms of OH are frequently non-specific or sometimes indistinguishable from a levodopa “off” state and syncope can also occur with little or no premonitory symptoms in PD. Consequently, PD patients suffering OH are often untreated/undertreated, leading to greater disability and healthcare assistance need than patients without dysautonomic symptoms .
In these complex situations, a telemedicine-based monitoring allowed to shorten distances between physicians and patients, providing a real-time window on patients’ clinical status necessary to establish prompt interventions.
Our data showed that a phone teleconsulting was necessary in 44 occasions during the whole monitoring and appropriate non-pharmacological measures to overcome OH episodes were suggested. During teleconsulting, patients were asked about their clinical status and their complaints in correspondence of the OH episode detection; moreover, their compliance to the recommended strategies was also monitored, showing an overall satisfactory adherence to the provided recommendations with in some cases subjective relief from symptoms.
Although consensus guidelines for the pharmacologic treatment of OH are lacking, randomized placebo-controlled clinical trials show that effective treatment of OH can help reduce symptomatic burden , increase physical activity levels , and improve motor functionality . This gives strength to the concept that a prompt recognition of OH and an adequate treatment may help prevent these negative consequences.
Finally, to assess the level of patient’s satisfaction about the proposed telemonitoring solution and service, the TUQ questionnaire was administered. The results obtained showed high average scores in all the explored items, even in the ease of use and learnability sub-item, pointing out a good usability of this telemedicine system also in the elderly. Interestingly, the higher average scores were recorded in the items of satisfaction and future use, reliability, and interaction quality, highlighting promising future perspectives and new potential fields of application of the proposed system.
In conclusion, this pilot study proposed a real-time remote home-monitoring system and protocol for patients with Parkinson’s disease and orthostatic hypotension and preliminary assessed its utility. The results highlighted the great usefulness of a PD–dedicated e-Health program able to monitor blood pressure, heart rate, SpO2, and temperature, in patients complicated with autonomic impairment manifesting OH, which might be further exacerbated by COVID-19 .
Despite some limitations due to the small sample size and the absence of a continuous monitoring, our data underline the clinical relevance of a prompt detection and management of OH phenomena in PD patients, in order to not underestimate this frequent complication and to reduce its consequences both on clinical status and on the need for health care assistance.
The proposed home-monitoring system and protocol have demonstrated to be feasible and to allow faster interventions in response to potential safety concerns in the PD population with OH, as well as in other pathologic conditions characterized by autonomic impairment. This could be particularly important in the PD population with OH, during the COVID-19 pandemic emergency period. Therefore, encouraging these alternative models of care based on the ICT technologies is of striking importance for the development of a patient-tailored care system with relevant implications on clinical management, research, and health care system organization. Moreover, the implemented video and phone teleconsulting has shown to be pivotal in this at risk population, especially during the emergency period, and may represent in synergy with vital signs smart-monitoring an effective and feasible strategy to provide the continuum of care and support health care system in the management of this potentially harmful PD complication.