Faculty Bibliography

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.
Copyright

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.

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.

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.

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 (

KEY POINTS/CONCLUSIONS:Individuals with Hereditary Sensory & Autonomic Neuropathy type III (HSAN III), also known as Riley-Day syndrome or Familial Dysautonomia, do not have functional muscle spindle afferents but do have essentially normal cutaneous mechanoreceptors Lack of muscle spindle feedback from the legs may account for the poor proprioception at the knee and the ataxic gait typical of HSAN III Given that functional muscle spindle afferents are also absent in the upper limb, we assessed whether proprioception at the elbow was likewise compromised Passive joint angle matching showed that proprioception was normal at the elbow, suggesting that individuals with HSAN III rely more on cutaneous afferents around the elbow ABSTRACT: Hereditary Sensory & Autonomic Neuropathy type III (HSAN III) is a rare neurological condition that features a marked ataxic gait that progressively worsens over time. We have shown that functional muscle spindle afferents are absent in the upper and lower limbs in HSAN III, and we have argued that this may account for the ataxia. We recently used passive joint angle matching to demonstrate that proprioception of the knee joint is very poor in HSAN III but can be improved towards normal by application of elastic kinesiology tape across the knee joints, which we attribute to the presence of intact cutaneous mechanoreceptors. Here we assessed whether proprioception was equally compromised at the elbow joint, and whether it could be improved through taping. Proprioception at the elbow joint was assessed using passive joint angle matching in 12 HSAN III patients and 12 age-matched controls. There was no difference in absolute error, gradient or correlation coefficient of the relationship between joint angles of the reference and indicator arms. Unlike at the knee, taping did not improve elbow proprioception in either group. Clearly, the lack of muscle spindles compromised proprioception at the knee but not at the elbow, and we suggest that the HSAN III patients rely more on proprioceptive signals from the skin around the elbow. This article is protected by copyright. All rights reserved.