Faculty Bibliography

Objective: We investigated whether activation of afferent and central baroreceptor pathways could differentiate between Lewy body disorders and MSA. Background: Clinical distinction between multiple system atrophy (MSA) and Lewy body disorders with motor involvement (Parkinson disease [PD] and dementia with Lewy bodies [DLB]) is sometimes challenging. Methods: Cross-sectional study including 35 patients with probable or possible MSA and 24 patients with Lewy body disorders (20 with PD and 4 with DLB). All subjects had neurogenic orthostatic hypotension. Subjects underwent complete autonomic testing with measurement of plasma levels of catecholamines and vasopressin after 10-min in the resting supine position and after 10-min of passive head-up tilt. Results: Thirty-five patients with probable MSA (22 MSA-C, 13 MSA-P) and 24 patients with Lewy body disorders (20 with PD, 4 with DLB) were included. All patients had documented neurogenic orthostatic hypotension. In patients with PD and DLB upright tilt induced marked hypotension and a significant increase in plasma vasopressin (from 0.82 +/- 0.77 to 4.85 +/- 13.9 pmol/l in PD (p = 0.0027); from 1.18 +/- 0.81 to 5.1 +/- 3.76 pmol/l in DLB (p = 0.11). In patients with MSA, upright tilt also elicited profound hypotension but circulating levels of vasopressin did not increase significantly (from 0.51 +/- 0.08 to 0.70 +/- 0.71 pmol/l, p = 0.092). Plasma norepinephrine did not increase significantly on head-up tilt in any of the subjects. A plasma vasopressin concentration during upright tilt of<=0.8 pmol/l in a patient with neurogenic orthostatic hypotension had a sensitivity of 91%, a specificity of 64%, and a negative predictive value of 83.3% for a diagnosis of MSA. Conclusions: Our results indicate that afferent and central baroreceptor pathways involved in vasopressin release are preserved in Lewy body disorders but impaired in MSA. Thus a patient with a vasopressin when standing of[0.8 pg/ml makes a diagnosis of MSA unlikely

Objectives: To report the preliminary results of the GLOMSAR survey for MSA. Background: Multiple system atrophy (MSA) is a rare fatal synucleinopathy characterized by Parkinsonian, pyramidal, cerebellar, and autonomic features in any combination. The GLObal MSA Registry (GLOMSAR) was established as an online contact registry for patients with MSA. Methods: Members of the Autonomic Disorders Consortium developed a web-based questionnaire comprising of 40-item with yes/no questions to evaluate the chronology and full spectrum of symptoms of MSA. GLOMSAR registrants were contacted by email on April 26 2017 and the survey was administered by the NIH's Rare Diseases Clinical Research Network (RDCRN). Results: Within 7 days, 155 registrants with MSA completed all 40 questions. Mean age was 62 years (range 30-92) and 58% were male. Frequent presenting symptoms were difficultly moving (28%), trouble with blood pressure or urination (23%), REM sleep behavior disorder (i.e., dream reenactment 23%) and falls (14%). Sixty-eight percent had been treated with levodopa and 30% experienced some benefit from it. Fifty-five percent reported using a wheelchair. Urinary incontinence was present in 65 and 30% required intermittent or indwelling urinary catheterization. Constipation occurred in 78%. Visual problems were reported in 65%. Of men, 91% reported erectile dysfunction; of women, 65% reported decreased genital sensation. Other findings included a high prevalence of depression (59%), hallucinations (21%) and a history of head trauma/concussion (22%). Conclusion: The GLOMSAR contact registry and web-based MSA survey are feasible ways to reach patients with MSA. This may be useful to support clinical research in this rare disease

Objective: The Multiple System Atrophy (MSA) Criteria Revision Steering Group identified the weaknesses of current set of diagnostic criteria for MSA and discussed a need for its revision. Background: Typically MSA is diagnosed half way through its clinical disease course. However, early diagnosis is critical if any diseasemodifying treatment is to be applied. Methods: The Steering Group includes investigators experienced in Parkinsonian, cerebellar, autonomic, neuroimaging, sleep, genetic and postmortem aspects of MSA. Shortcomings of the current diagnostic criteria for MSA were addressed through the personal communication. Results: The first criteria for MSA diagnosis were published in 1989, the first Consensus Criteria in 1998, and the second Consensus Criteria in 2008. A study of "red flags" was also published in 2008 but the results not incorporated into the criteria. In a recent large autopsy study by Koga et al., 2015 38% of cases diagnosed in life with MSA did not have it, the largest misdiagnosed group having dementia with Lewy bodies. In a study examining validity of Consensus Criteria (Osaki et al., 2009), sensitivity for MSA diagnosis was 41% for possible and 18% for probable at first visit, whereas at last visit these figures were 92 and 63% respectively. There is clearly a need for improved sensitivity and specificity of diagnosis of MSA, especially at its earliest stages. Conclusions: It is time in 2018 to revisit and revise the Consensus Criteria for the diagnosis of MSA

Objective: To define which factors predict the pressor response to droxidopa in patients with neurogenic orthostatic hypotension (nOH). Background: Droxidopa, a synthetic norepinephrine precursor, was recently approved to treat symptomatic nOH. The pressor response is variable with some patients responding to doses of 100 mg while others requiring up to 600 mg three times/day. It is not known which factors predict the magnitude of the pressor response to droxidopa. Methods: We prospectively evaluated the BP response to increasing doses of droxidopa in patients with nOH in an outpatient setting. BP supine and after 3-min standing was measured before and 1-h after oral administration of 100 mg of droxidopa. Droxidopa was progressively increased until (1) complete relief of symptoms, (2) supine systolic BP[180 mmHg, (3) occurrence of side effects, or (4) the maximum dose of 600 mg was reached. Results: Sixteen subjects with nOH (6 with Parkinson disease, 5 with pure autonomic failure-PAF-, 3 with autoimmune autonomic ganglionopathy-AAG-, and 2 with multiple system atrophy) were evaluated. Mean BP was 126 +/- 28/72 +/- 11 mmHg supine, and 89 +/- 19/53 +/- 15 mmHg after 3-min standing (fall of 37/18 mmHg). Mean plasma norepinephrine while supine was 192 +/- 216 pg/ml. Maximum droxidopa dose during the titration was 212 +/- 102 mg (range 100-400 mg). Droxidopa increased BP to an average of 148 +/- 53/90 +/- 13 mmHg supine and 135 +/- 38/66 +/- 16 mmHg after 3-min standing (p<=0.001). Plasma norepinephrine levels were inversely correlated with higher systolic BP after-3 min standing following droxidopa treatment (R2 = 0.42; p = 0.023). Four patients (3 with AAG and 1 with PAF) with very low plasma norepinephrine levels (<=90 pg/ml) experienced transient nausea, vomiting, and abdominal pain during titration with dosages of 200 mg. In these patients, treatment with 100 mg/day was effective and well tolerated. Diagnostic categories did not predict response to droxidopa. Conclusions: In patients with nOH, lower plasma norepinephrine levels are associated with a greater pressor response to droxidopa. This response is probably related to the degree of denervation supersensitivity. Supine norepinephrine levels may be useful to predict appropriate dosing of droxidopa in the clinical setting

Objective: To evaluate the efficacy of droxidopa on symptoms of neurogenic orthostatic hypotension (nOH) and activities of daily living using the Orthostatic Hypotension Questionnaire (OHQ) in patients with multiple system atrophy (MSA). Background: Droxidopa is an oral prodrug of norepinephrine with demonstrated efficacy in patients with primary autonomic failure (pure autonomic failure, MSA, and Parkinson disease) who have nOH. Design/Methods: We conducted a subset analysis of data from three droxidopa (Studies NOH301, NOH302, NOH303) clinical trials which enrolled over 400 patients with primary autonomic failure, including 95 patients with MSA, 56 of which were randomized into double-blind treatment periods of the studies. Changes in symptoms of nOH and in symptom impact on activities of daily living were measured via the OHQ. Safety was measured via the incidence and severity of adverse events. Results: There were statistically significant (P<=0.05) improvements in OHQ composite score after droxidopa treatment versus placebo in the combined analysis of Studies NOH301 and NOH302, although the total number of MSA patients was relatively small. Patients treated with droxidopa demonstrated numerically greater improvements than placebo-treated patients in nine of ten OHQ items. Standing systolic blood pressure improved with droxidopa treatment. Data suggests that 4-6 weeks of treatment may be required to reach full symptomatic benefit with the drug. Importantly, despite the progressive nature of MSA, the symptomatic and blood pressure benefits were maintained through 3 months of open label extension treatment. Droxidopa was well tolerated and safe in MSA patients and the overall population. Conclusions: Droxidopa was shown in this post hoc, subset analysis to be a useful therapy for the treatment and management of nOH in MSA patients, providing symptomatic relief associated with improvement in standing blood pressure and an excellent safety profile

Multiple system atrophy (MSA) is a rare neurodegenerative disorder with substantial knowledge gaps despite recent gains in basic and clinical research. In order to make further advances, concerted international collaboration is vital. In 2014, an international meeting involving leaders in the field and MSA advocacy groups was convened in Las Vegas, Nevada, to identify critical research areas where consensus and progress was needed to improve understanding, diagnosis, and treatment of the disease. Eight topic areas were defined: pathogenesis, preclinical modeling, target identification, endophenotyping, clinical measures, imaging biomarkers, nonimaging biomarkers, treatments/trial designs, and patient advocacy. For each topic area, an expert served as a working group chair and each working group developed priority-ranked research recommendations with associated timelines and pathways to reach the intended goals. In this report, each groups' recommendations are provided.

OBJECTIVE:To assess vestibular function in patients with familial dysautonomia (FD), a hereditary sensory and autonomic neuropathy - caused by a mutation in the IKBKAP gene (c.2204 + 6 T>C) - and characterized by marked gait ataxia. METHODS:Cervical and vestibular evoked myogenic potentials (cVEMPs and oVEMPs) were recorded from the sternocleidomastoid (SCM) and extraocular muscles in 14 homozygous patients, 2 heterozygous patients, and 15 healthy controls during percussion of the forehead. RESULTS:cVEMP and oVEMP amplitudes were significantly lower, and peak latencies significantly delayed, in the FD patients. There were no differences in overall EMG during attempted maximal voluntary contractions of the SCM muscle, suggesting intact efferent function. The two heterozygotes with a minor haplotype missense (R696P) mutation in exon 19 of the IKBKAP gene had cVEMP responses less affected than the homozygous. CONCLUSIONS:The founder mutation in the IKBKAP gene affects the development of vestibular afferent pathways, leading to attenuated cVEMPs. SIGNIFICANCE/CONCLUSIONS:Vestibular abnormalities may contribute to the gait ataxia in FD.

Cardiovascular autonomic dysfunctions, including neurogenic orthostatic hypotension, supine hypertension and post-prandial hypotension, are relatively common in patients with Parkinson disease. Recent evidence suggests that early autonomic impairment such as cardiac autonomic denervation and even neurogenic orthostatic hypotension occur prior to the appearance of the typical motor deficits associated with the disease. When neurogenic orthostatic hypotension develops, patients with Parkinson disease have an increased risk of mortality, falls, and trauma-related to falls. Neurogenic orthostatic hypotension reduces quality of life and contributes to cognitive decline and physical deconditioning. The co-existence of supine hypertension complicates the treatment of neurogenic orthostatic hypotension because it involves the use of drugs with opposing effects. Furthermore, treatment of neurogenic orthostatic hypotension is challenging because of few therapeutic options; in the past 20 years, the US Food and Drug Administration approved only two drugs for the treatment of this condition. Small, open-label or randomized studies using acute doses of different pharmacologic probes suggest benefit of other drugs as well, which could be used in individual patients under close monitoring. This review describes the pathophysiology of neurogenic orthostatic hypotension and supine hypertension in Parkinson disease. We discuss the mode of action and therapeutic efficacy of different pharmacologic agents used in the treatment of patients with cardiovascular autonomic failure.