Faculty Bibliography

Background: In neurogenic orthostatic hypotension (nOH), blood pressure (BP) falls due to inadequate norepinephrine (NE) release when upright. Ampreloxetine, a novel, long-acting NE reuptake inhibitor, potentiates effects of endogenous NE and has shown durable symptom improvement in subjects with nOH associated with synucleinopathies. The objective of this study was to evaluate measures of BP regulation in subjects with symptomatic nOH treated with open-label ampreloxetine.
Method(s): In a phase 2, multicenter, exploratory study, subjects received ampreloxetine once-daily (3-20 mg) for up to 20 weeks, with 4-week follow-up after ampreloxetine withdrawal and restarting other pressor agents. Assessments included Orthostatic Hypotension Symptom Assessment Item 1 score (OHSA#1; dizziness, lightheadedness, feeling faint); standing, sitting, and supine systolic BP (SBP); standing duration; and plasma NE.
Result(s): Seventeen symptomatic subjects (baseline OHSA#1 score >4) were enrolled (mean age, 65 years). Standing and sitting SBP, standing duration, plasma NE, and symptoms improved from Weeks 1 to 20. Mean increase in 3-minute standing SBP from baseline was 9.0 mmHg at Week 4 and 10.8 mmHg at Week 20; >50% of subjects maintained SBP >80 mmHg. Sitting SBP changes were less, with little change in supine SBP. At Week 4, 67% of subjects could stand for >5 mins, 31% improvement from baseline. NE plasma levels rose from pre-dose to Week 4 (1664.93-2231.67 pmol/l). After ampreloxetine withdrawal and restarting other pressor agents, standing SBP remained increased; however, nOH symptoms deteriorated to baseline. Ampreloxetine was well tolerated.
Conclusion(s): Ampreloxetine has previously demonstrated durable symptom improvement in nOH. Symptom improvement was accompanied by increase in standing and sitting SBP, standing duration, and NE plasma levels, with little effect on supine SBP. These encouraging findings are being evaluated further in ongoing Phase 3, double-blind, confirmatory studies in subjects with nOH and synucleinopathies.
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Acute-onset and severe sensory and autonomic deficits with no motor dysfunction, typically preceded by a febrile illness, with poor recovery, and often fatal outcome are the hallmark features of acute sensory and autonomic neuronopathy (ASANN). Pathologically and electrophysiologically, ASANN is characterized by an extensive ganglionopathy affecting sensory and autonomic ganglia with preservation of motor neurons. Consequently, patients, usually children or young adult, develop acute-onset profound widespread loss of all sensory modalities resulting in automutilations, as well as autonomic failure causing neurogenic orthostatic hypotension, neurogenic underactive bladder, and gastroparesis and constipation. The diagnosis is clinical with support of nerve conduction studies and autonomic testing, as well as spinal cord magnetic resonance imaging showing characteristic posterior cord hyperintensities. Although the presumed etiology is immune-mediated, further studies are required to clarify the physiopathology of the disease. We here performed a systematic review of the epidemiology, pathophysiology, diagnosis, and management of ASANN, with three representative cases that recently presented at our clinic. All three patients had the typical clinical manifestations of ASANN but in different combinations, illustrating the variable phenotype of the disorder. Immunosuppression is seldom effective. Management options are limited to supportive and symptomatic care with the goal of minimizing complications and preventing death.

Neurogenic orthostatic hypotension (nOH) is among the most debilitating nonmotor features of patients with Parkinson's disease (PD) and other synucleinopathies. Patients with PD and nOH generate more hospitalizations, make more emergency room visits, create more telephone calls/mails to doctors, and have earlier mortality than those with PD but without nOH. Overall, the health-related cost in patients with PD and OH is 2.5-fold higher compared with patients with PD without OH. Hence, developing effective therapies for nOH should be a research priority. In the last few decades, improved understanding of the pathophysiology of nOH has led to the identification of therapeutic targets and the development and approval of two drugs, midodrine and droxidopa. More effective and safer therapies, however, are still needed, particularly agents that could selectively increase blood pressure only in the standing position because supine hypertension is the main limitation of available drugs. Here we review the design and conduct of nOH clinical trials in patients with PD and other synucleinopathies, summarize the results of the most recently completed and ongoing trials, and discuss challenges, bottlenecks, and potential remedies.

Background: Inadequate norepinephrine (NE) release in neurogenic orthostatic hypotension (nOH) causes blood pressure to fall on standing and debilitating symptoms of cerebral hypoperfusion. Ampreloxetine, a novel, long-acting NE reuptake inhibitor, potentiates the effects of endogenous NE, and may improve symptoms of nOH. The objective of the study was to explore the durability of effect and safety of once-daily oral ampreloxetine for the symptomatic treatment of nOH in subjects with synucleinopathies.
Method(s): In an open-label, phase 2, exploratory, multicenter study, subjects received open-label ampreloxetine (3-20 mg) once-daily for up to 20 weeks, with 4-week follow-up after ampreloxetine withdrawal and restarting alternative pressor agents. Assessments included Orthostatic Hypotension Symptom Assessment Item 1 (OHSA#1; dizziness, lightheadedness, feeling faint), OHSA and Orthostatic Hypotension Daily Activities Scale (OHDAS) composite scores, and Patient Global Impression of Severity (PGI-S).
Result(s): Seventeen symptomatic subjects (baseline OHSA#1 score >4) were enrolled (mean age, 65 years). At Week 4, mean (SD) improvement on OHSA#1 was -3.8 (3.1) points; approximately 77% of subjects reported >=1-point improvement (minimal clinically important difference). At Week 20, mean improvement was -3.1 (3.0) points; approximately 86% reported >=1-point improvement. Symptom improvement was observed as early as Week 1 and was sustained throughout the study. Deterioration to baseline symptom severity was after ampreloxetine withdrawal. Similar trends were seen in OHSA and OHDAS composite scores, and PGI-S. Most common adverse events were urinary tract infection (24%), hypertension (19%), and headache (14%), with no study-drug related serious adverse events.
Conclusion(s): Ampreloxetine showed durable symptom improvement in symptomatic subjects with nOH over 20 weeks, with return to baseline symptom severity after ampreloxetine withdrawal. Ampreloxetine was well tolerated with a favorable safety profile. These encouraging open-label findings are being evaluated further in ongoing Phase 3, double-blind, confirmatory studies in subjects with nOH and synucleinopathies.
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Head and neck tumors can affect afferent baroreceptor neurons and either interrupt or intermittently increase their signaling, causing blood pressure to become erratic. When the afferent fibers of the baroreflex are injured by surgery or radiotherapy or fail to develop as in familial dysautonomia, their sensory information is no longer present to regulate arterial blood pressure, resulting in afferent baroreflex failure. When the baroreflex afferents are abnormally activated, such as by paragangliomas in the neck, presumably by direct compression, they trigger acute hypotension and bradycardia and frequently syncope, by a mechanism similar to the carotid sinus syndrome. We describe our observations in a large series of 23 patients with afferent baroreflex dysfunction and the cardiovascular autonomic features that arise when the sensory baroreceptor neurons are injured or compressed. The management of afferent baroreceptor dysfunction is limited, but pharmacological strategies can mitigate blood pressure swings, improve symptoms, and may reduce hypertensive organ damage. Although rare, the prevalence of afferent baroreflex dysfunction appears to be increasing in middle-aged men due to human papillomavirus related oropharyngeal cancer.

Background: To assess acute clinical effects and safety of single-dose oral ampreloxetine, a novel, long-acting, selective norepinephrine reuptake inhibitor in subjects with neurogenic orthostatic hypotension (nOH).
Method(s): In a 5-day dosing study, subjects received placebo on Day 1, followed by ascending doses of ampreloxetine (range:1-20 mg). A subset of subjects were randomized to placebo or ampreloxetine in a 1-day double-blind study. Assessments included change in seated and standing systolic blood pressure (SBP), and Orthostatic Hypotension Symptom Assessment-Item 1 (OHSA#1; dizziness, lightheadedness, feeling faint).
Result(s): Of 34 subjects (mean age, 66 years), 15 and 13 subjects received ampreloxetine 10 and 20 mg, respectively, as maximum tolerated dose. Ampreloxetine 10 mg showed the most consistent response for increase in seated SBP relative to placebo (mean [SD] change in seated SBP 4.9 [20.1] mmHg more than placebo 4 hours post-dose). In the double-blind study (ampreloxetine, n=5 [median dose, 10 mg]; placebo, n=5), relative to placebo, for the ampreloxetine treatment group, increase in seated (mean difference from placebo, 29.9 mmHg at 4 hours post-dose; p < 0.05) and 3-minute standing SBP (mean difference, 35.0 mmHg at 4 hours post-dose) was more pronounced for the ampreloxetine treatment group to 9 hours and 10 hours post-dose, respectively, and 3-minute standing SBP was more pronounced for subjects randomized to ampreloxetine up to 10 hours post-dose. Twice as many subjects in the ampreloxetine treatment arm reported symptom improvement on OHSA#1. Most common adverse events were headache and urinary tract infection, with no serious events.
Conclusion(s): In subjects with nOH, 10 mg ampreloxetine produced a consistent increase in seated SBP relative to placebo. Compared to placebo, ampreloxetine showed greater increase in seated and standing SBP up to 10 hours post-dose, and greater symptom improvement. Ampreloxetine was well tolerated. These results support assessment of longer-term effects of ampreloxetine in nOH.
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Objective: To develop a clinical score to distinguish between the parkinsonian variant of multiple system atrophy (MSA-P) and Parkinson's disease (PD).
Background(s): The differential diagnosis between MSA-P and PD is often difficult, particularly early in the disease course.
Method(s): We compared patients with probable MSA-P and with PD with a disease duration of <3 years, selected from those who were enrolled in the Natural History Study of the Synucleinopathies, an international prospective observational study. Detailed clinical neurological, and autonomic parameters were assessed at enrollment using UMSARS part I, II and IV; Schrag quality of life (QoL) scale; burden of autonomic dysfunction by COMPASS-31 scale; smell function using the UPSIT; cardiovascular autonomic function using heart rate variability during deep-breathing, analysis of the Valsalva maneuver, orthostatic stress test, plasma catecholamine levels during supine rest and after head-up tilt; and cognitive evaluation using MoCA. Positive and negative likelihood ratios (LR) were obtained for each variable assessed. Multiple iterations of a composite score based on sequential addition of variables with the highest diagnostic accuracy were created by multiplying each variable's LR and applying a logarithmic function.
Result(s): Fifty-eight MSA-P and 53 PD patients had a disease duration of less than 3 years. The vast majority of patients had been diagnosed within the last 12 months (81% MSA-P and 66% PD patients). MSA-P patients were more frequently female (53% vs. 30% p<0.05) and younger at diagnosis (63+/-8 years vs. 71+/-8 years, p<0.001). A 7-item score comprising the bladder weighted subscore of the COMPASS-31, UMSARS's part 1, UPSIT, hyperreflexia, the motor subscore of Schrag's MSA quality of life scale, falls within 3 years of diagnosis, and new or increased snoring resulted in a ROC curve AUC of 0.983, with excellent 93% sensitivity and 98% specificity to distinguish early MSA-P from PD.
Conclusion(s): We propose a scale of 7 clinical items to distinguish early stage MSA-P from PD. It considers urinary function, olfactory function, corticospinal signs, performance of activities of daily living, motor symptoms burden on quality of life, frequent early falls and sleep disordered breathing. We are now prospectively validating the scale to determine its predictive value in our prodromal cohort. (Figure Presented)

Objective: To study the rate of progression of multiple system atrophy (MSA) and assess for a potential ceiling effect of the Unified Multiple System Atrophy Rating Scale (UMSARS).
Background(s): Disease progression of MSA as measured by UMSARS varied significantly in natural history studies. Reported 1-year UMSARS-1 and UMSARS-2 progression rates ranged from 3.9 to 6.5 and 3.5 to 8.2 respectively. We hypothesize that this variability is due, at least in part, to differences in severity at enrollment and a potential ceiling effect in the scale, so that patients in more advanced stages may appear to worsen less, which would have important implications for clinical trial design.
Method(s): We analyzed the rate of change in the UMSARS in a large international cohort of well-characterized patients with a clinical diagnosis of possible or probable MSA enrolled in the Natural History Study of Synucleinopathies. Annualized progression rates were obtained using 2-year follow-up data.
Result(s): Three hundred and forty nine patients (61.4+/-7.9 years old) with MSA were enrolled. Disease duration was 4.5+/-5.1 years. 143 patients completed 1-year evaluations and 61 completed the 2-year evaluation. The 12-month progression rates were 5.4+/-5.1 for the UMSARS-I, 5.9+/-5.3 for the UMSARS-II, and 11.8+/-9.6 for the total score. The 24-month progression rates were 10.8+/-7.3 for the UMSARS-I, 12.2+/-7.9 for the UMSARSII, and 22.6+/-13.7 for the total score. Annualized progression rates were divided according to their baseline UMSARS-I and UMSARS II. There was a significant (p = 0.0153) inverse relationship between rate of progression and UMSARS-I at baseline. A similar, but not significant trend was observed with UMSARS-II at baseline.
Conclusion(s): The rate of progression as measured by UMSARS is influenced by the baseline disease severity. A possible ceiling effect should be considered when planning enrollment, power calculations, and outcome measures in clinical trials

Objective: To confirm: 1) clinical efficacy and safety of once-daily oral ampreloxetine in a 4-week double-blind (