Faculty Bibliography

Background: Disease progression of multiple system atrophy (MSA) as measured by the Unified Multiple System Atrophy Rating Scale (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): 293 patients (62.0+/-7.8 years old) with MSA were enrolled. Disease duration was 4.5+/-3.6 years. 98 patients completed 1-year evaluations and 48 completed the 2-year evaluation. The 12-month progression rates were 5.5+/-5.3 for the UMSARS-I, 6.6+/-5.2 for the UMSARS-II, and 11.9+/-9.8 for the total score. The 24-month progression rates were 10.8+/-7.1 for the UMSARS-I, 12.5+/-7.9 for the UMSARS-II, 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=0.0461) 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 ceiling effect should be considered when planning enrollment, power calculations, and outcome measures in clinical trials

Background: Multiple system atrophy (MSA) is a fatal and poorly understood rare neurodegenerative disorder. Here we describe the baseline characteristics of patients with MSA enrolled in a prospective multicenter and multinational NIH-sponsored Natural History Study of the Synucleinopathies.
Method(s): Patients with a clinical diagnosis of probable or possible MSA were prospectively enrolled at 11 participating centers. Demographic data, clinical variables, and autonomic testing results were included.
Result(s): 293 patients with MSA (125 women) have been enrolled. MSA-C was predominant (154 patients, 52.6%). Mean age at symptom onset was 57.6+/-8.4 (mean+/-SD) and at enrollment was 62.0+/-7.8 years old. UMSARS-1 was 21.1+/-7.6 and UMSARS-2 was 21.2+/-9.1. MoCA score was 26.3+/-4.4 indicating normal cognition. In the supine position, blood pressure (systolic BP/diastolic BP) was 143.0+/-25.2/84.0+/-14.5 mmHg, and heart rate was 75.0+/-11.5 bpm. After 3-min head-up tilt, BP fell to 113.1+/-25.5/69.6+/-15.9 mmHg and HR increased to 82.9+/-12.7 bpm. Supine plasma norepinephrine levels were 365.4+/-408.5 pg/ml and increased only to 449.8+/-277.2 pg/ml upon head-up tilt indicating impaired baroreflex-mediated sympathetic activation. The University of Pennsylvania Smell Identification Test (UPSIT) score was 28.5+/-8.1 indicating preserved olfaction. Probable rapid eye movement (REM) sleep behavior disorder was reported by 85%.
Conclusion(s): This is the largest cross-sectional sample of patients with MSA recruited consecutively reported so far. Our results confirm that: i) symptom onset in MSA is remarkable consistent at 57 years; ii) overt cognitive impairment is not a typical feature; iii) sympathetic and cardiovagal deficits are present; iv) olfaction is preserved, and; v) probable REM behavior disorder is very frequent. The prospective follow-up of these patients will provide additional information on the natural history of the disease

Patients with Hereditary Sensory & Autonomic Neuropathy type III exhibit marked ataxia, including gait disturbances. We recently showed that functional muscle spindle afferents in the leg, recorded via intraneural microelectrodes inserted into the peroneal nerve, are absent in HSAN III, although large-diameter cutaneous afferents are intact. Moreover, there is a tight correlation between loss of proprioceptive acuity at the knee and the severity of gait impairment. We tested the hypothesis that manual motor performance is also compromised in HSAN III, attributed to the predicted absence of muscle spindles in the intrinsic muscles of the hand. Manual performance in the Purdue pegboard task was assessed in 12 individuals with HSAN III and 11 age-matched healthy controls. The mean (SD) pegboard score (number of pins inserted in 30 s) was 8.11.9 and 8.61.8 for the left and right hand respectively, significantly lower than the scores for the controls (15.01.3 and 16.01.1; p<0.0001). Performance was not improved after applying kinesiology tape over the joints of the hand. In five patients we inserted a tungsten microelectrode into the ulnar nerve at the wrist. No spontaneous or stretch-evoked muscle afferent activity could be identified in any of the 11 fascicles supplying intrinsic muscles of the hand, whereas rich tactile afferent activity could be recorded from four cutaneous fascicles. We conclude that functional muscle spindles are absent in the hand, and most likely absent in the long finger flexors and extensors, and that this largely accounts for the poor manual motor performance in HSAN III.

OBJECTIVE:To test whether the plasma levels of norepinephrine (NE) in patients with neurogenic orthostatic hypotension (nOH) predict their pressor response to droxidopa. METHODS:This was an observational study, which included patients with nOH. All patients had standardized autonomic function testing including determination of venous plasma catecholamine levels drawn through an indwelling catheter while resting supine. This was followed by a droxidopa titration with 100 mg increments in successive days until relief of symptoms, side effects, or the maximum dose of 600 mg was reached. No response was defined as an increase of <10 mm Hg in systolic blood pressure (BP) after 3-minute standing 1 hour after droxidopa administration. Nonlinear regression models were used to determine the relationship between BP response and plasma NE levels. RESULTS:= 0.0023). CONCLUSIONS:In patients with nOH, lower supine resting plasma NE levels are associated with a greater pressor effect of droxidopa treatment. This finding should help identify patients with nOH most likely to respond to standard doses of droxidopa. CLASSIFICATION OF EVIDENCE/METHODS:This study provides Class I evidence that lower supine plasma NE levels accurately identify patients with nOH more likely to have a greater pressor effect from droxidopa.

Patients with hereditary sensory and autonomic neuropathy type III(HSAN III) exhibit marked gait disturbances. The cause of the gaitataxia is not known, but we recently showed that functional musclespindle afferents in the leg, recorded via intraneural microelectrodesinserted into the peroneal nerve, are absent in HSAN III, althoughlarge-diameter cutaneous afferents are intact. Moreover, there is atight correlation between loss of proprioceptive acuity at the knee andthe severity of gait impairment. Here we tested the hypothesis thatmanual motor performance is also compromised in HSAN III,attributed to the predicted absence of muscle spindles in the intrinsicmuscles of the hand. Manual performance in the Purdue pegboardtask was assessed in 12 individuals with HSAN III and 12 age-matched healthy controls. The mean (+/- SD) pegboard score (number ofpins inserted in 30 s) was 8.1 +/- 1.9 and 8.6 +/- 1.8 for the left andright hand respectively, significantly lower than the scores for thecontrols (14.3 +/- 2.9 and 15.5 +/- 2.0; P <0.0001). In five patients weinserted a tungsten microelectrode into the ulnar nerve at the wrist.No spontaneous or stretch-evoked muscle afferent activity could beidentified in any of the 11 fascicles supplying intrinsic muscles of thehand, whereas rich tactile afferent activity could be recorded from 4cutaneous fascicles. We conclude that functional muscle spindles areabsent in the hand, and likely absent in the long finger flexors andextensors, and that this largely accounts for the poor manual motorperformance in HSAN III

Hereditary sensory and autonomic neuropathy type III (HSAN III)features a marked ataxic gait that progressively worsens over time.We recently assessed whether proprioceptive disturbances can explainthe ataxia. Proprioception at the knee joint was assessed using passivejoint angle matching in 18 patients and 14 age-matched controls; fivepatients with cerebellar ataxia were also studied. Ataxia was quantified using the Brief Ataxia Rating Score, which ranged from 7 to26/30. Patients with HSAN III performed poorly in judging jointposition at the knee: mean (+/- SE) absolute error was 8.7 +/- 1.0 andthe range was very wide (2.8-18.1); conversely, absolute error wasonly 2.7 +/- 0.3 (1.6-5.5) in the controls and 3.0 +/- 0.2 (2.1-3.4) in the cerebellar patients. This error was positively correlated tothe degree of ataxia in patients with HSAN III but not in patients withcerebellar ataxia. However, using the same approach at the elbowrevealed no significant differences in mean error in 12 patients withHSAN III (4.8 +/- 1.2; 3.0-7.2) and 12 age-matched controls(4.1 +/- 1.1; 2.1-5.5). Interestingly, microelectrode recordingsfrom the peroneal nerve showed a complete absence of spontaneousor stretch-evoked muscle afferent activity, confirmed in the ulnarnerve. Clearly, the lack of muscle spindles compromised proprioception at the knee but not at the elbow, and we suggest that patientswith HSAN III have learned to rely more on proprioceptive signalsfrom the skin around the elbow. Indeed, applying longitudinal stripsof elastic tape around the joint to increase tensile strain in the skinimproved proprioception at the knee but not the elbow

PURPOSE/OBJECTIVE:Patients suffering from cardiovascular autonomic failure often develop neurogenic supine hypertension (nSH), i.e., high blood pressure (BP) in the supine position, which falls in the upright position owing to impaired autonomic regulation. A committee was formed to reach consensus among experts on the definition and diagnosis of nSH in the context of cardiovascular autonomic failure. METHODS:As a first and preparatory step, a systematic search of PubMed-indexed literature on nSH up to January 2017 was performed. Available evidence derived from this search was discussed in a consensus expert round table meeting in Innsbruck on February 16, 2017. Statements originating from this meeting were further discussed by representatives of the American Autonomic Society and the European Federation of Autonomic Societies and are summarized in the document presented here. The final version received the endorsement of the European Academy of Neurology and the European Society of Hypertension. RESULTS:In patients with neurogenic orthostatic hypotension, nSH is defined as systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg, measured after at least 5 min of rest in the supine position. Three severity degrees are recommended: mild, moderate and severe. nSH may also be present during nocturnal sleep, with reduced-dipping, non-dipping or rising nocturnal BP profiles with respect to mean daytime BP values. Home BP monitoring and 24-h-ambulatory BP monitoring provide relevant information for a customized clinical management. CONCLUSIONS:The establishment of expert-based criteria to define nSH should standardize diagnosis and allow a better understanding of its epidemiology, prognosis and, ultimately, treatment.