The Degree of Cardiovascular Autonomic Dysfunction is not Different in GBA-Related and Idiopathic Parkinson's Disease Patients: A Case-Control Instrumental Evaluation.

Background: Increased prevalence of cardiovascular autonomic failure might play a key role on Parkinson's disease (PD) progression of glucocerebrosidase gene (GBA)-mutated patients, determining a malignant phenotype of disease in these patients. Objective: To objectively characterize, for the first time, the cardiovascular autonomic profile of GBA-mutated patients compared to idiopathic PD patients by means of cardiovascular reflex tests (CRTs). Methods: This is a case-control (1 : 2) study on PD patients belonging to well-characterized prospective cohorts. For each PD patient carrying GBA variants, two idiopathic PD patients, matched for sex and disease duration at CRTs, were selected. Patients recruited in these cohorts underwent a complete clinical and instrumental evaluation including specific autonomic questionnaires, CRTs and extensive genetic analysis. Results: A total of 23 GBA-PD patients (19 males, disease duration 7.7 years) were included and matched with 46 non-mutated PD controls. GBA-mutated patients were younger than controls (59.9±8.1 vs. 64.3±7.2 years, p = 0.0257) and showed a more severe phenotype. Despite GBA-mutated patients reported more frequently symptoms suggestive of orthostatic hypotension (OH) than non-mutated patients (39.1% vs 6.5%, p = 0.001), the degree of cardiovascular autonomic dysfunction, when instrumentally assessed, did not differ between the two groups, showing the same prevalence of neurogenic OH, delayed OH and cardiovascular reflex impairment (pathological Valsalva maneuver). Conclusion: GBA-PD patients did not show different instrumental cardiovascular autonomic pattern than non-mutated PD. Our findings suggested that symptoms suggestive of OH should be promptly investigated by clinicians to confirm their nature and improve patient care and management.

Levodopa-induced orthostatic hypotension in parkinsonism: A red flag of autonomic failure.

BACKGROUND AND PURPOSE: Levodopa (LD) is the main treatment for parkinsonism, but its use may be limited by a potential hypotensive effect. METHODS: We evaluated the cardiovascular effect of LD performing head-up tilt test (HUTT) before and 60 min after 100/25 mg LD/dopa-decarboxylase inhibitor (pre-LD vs. post-LD HUTT) in 164 patients with parkinsonism on chronic LD treatment. Features predictive of LD-induced orthostatic hypotension (OH) were assessed by logistic regression analysis. RESULTS: Basal supine blood pressure (BP) and heart rate (HR) decreased after LD. During post-LD HUTT, BP drop and HR increase were significantly greater than at pre-LD HUTT. Thirty-eight percent of patients had OH at post-LD HUTT compared to 22% of patients presenting OH at pre-LD HUTT (p < 0.001). Risk factors for LD-induced/worsened OH were pre-LD OH (odds ratio [OR] = 36, 95% confidence interval [CI] = 10-131), absence of overshoot at Valsalva maneuver (OR = 9, 95% CI = 4-20), and pathological Valsalva ratio (OR = 6, 95% CI = 2-15). CONCLUSIONS: LD administration caused/worsened hypotension in both supine and orthostatic conditions. Patients with cardiovascular autonomic failure had a higher risk of developing LD-induced OH. In clinical practice, LD-induced OH could represent a red flag for cardiovascular autonomic failure.

Effects of Spinal Cord Injury Site on Cardiac Autonomic Regulation: Insight from Analysis of Cardiovascular Beat by Beat Variability during Sleep and Orthostatic Challenge.

PURPOSE: The goal of this study on Spinal Cord Injury (SCI) patients with cervical or thoracic lesion was to assess whether disturbances of ANS control, according to location, might differently affect vagal and sympatho-vagal markers during sleep and orthostatic challenge. We analyzed with linear and nonlinear techniques beat-by-beat RR and arterial pressure (and respiration) variability signals, extracted from a polysomnographic study and a rest-tilt test. We considered spontaneous or induced sympathetic excitation, as obtained shifting from non-REM to REM sleep or from rest to passive tilt. We obtained evidence of ANS cardiac (dys)regulation, of greater importance for gradually proximal location (i.e., cervical) SCI, compatible with a progressive loss of modulatory role of sympathetic afferents to the spinal cord. Furthermore, in accordance with the dual, vagal and sympathetic bidirectional innervation, the results suggest that vagally mediated negative feedback baroreflexes were substantially maintained in all cases. Conversely, the LF and HF balance (expressed specifically by normalized units) appeared to be negatively affected by SCI, particularly in the case of cervical lesion (group p = 0.006, interaction p = 0.011). Multivariate analysis of cardiovascular variability may be a convenient technique to assess autonomic responsiveness and alteration of functionality in patients with SCI addressing selectively vagal or sympathetic alterations and injury location. This contention requires confirmatory studies with a larger population.

Neurogenic orthostatic hypotension in early stage Parkinson's disease: New insights from the first 105 patients of the BoProPark study.

OBJECTIVES: The prevalence of neurogenic orthostatic hypotension (NOH, due to cardiovascular autonomic failure) at early stage of Parkinson's disease (PD) is unknown. The aims of this study are to prospectively evaluate in a cohort of PD patients recruited within 3 years from motor onset (1) cardiovascular autonomic functions by means of cardiovascular reflex tests (CRTs) and the occurrence of NOH; (2) the frequency of orthostatic symptoms with a validated questionnaire. METHODS: We included the first 105 PD patients of the prospective "BoProPark" study. Each patient underwent CRTs (head up tilt test; Valsalva manoeuvre; deep breathing; cold face test and handgrip test) under continuous blood pressure monitoring according to standardized procedures and SCOPA-Aut questionnaire at baseline (T0) and after 16 months (T1). A group of 50 age- and sex-matched controls was used for comparison. RESULTS: At T0 (mean age 61 ± 9 years, disease duration 19 ± 9 months) NOH was detected in 4/105 (3.8%) patients, whereas at T1 in 8/105 (7.6%). CRTs responses assessing sympathetic function were impaired at T0 in PD patients compared to controls and progressively worsened at T1. Only 1 patient at T0 and 3 at T1 with NOH reported orthostatic symptoms with low frequency, while the majority of patients reporting these symptoms did not have OH at testing. CONCLUSIONS: Our prospective study shows that NOH is not common at early PD stage. Asymptomatic mild sympathetic impairment was observed at first evaluation and progressed with disease evolution. Secondary OH may account for the higher prevalence of OH in PD reported so far.

Circadian and state-dependent core body temperature in people with spinal cord injury.

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To analyze the circadian rhythm and state-dependent modulation of core body temperature (Tcore) in individuals with spinal cord injury (SCI) under controlled environmental conditions. SETTING: Institute of the Neurological Sciences of Bologna, Italy. METHODS: We assessed 48-h rectal Tcore and sleep-wake cycle by means of video-polygraphic recording in five cervical SCI (cSCI), seven thoracic SCI (tSCI), and seven healthy controls under controlled environmental conditions. RESULTS: cSCI showed higher night-time Tcore values with reduced nocturnal decrease, higher MESOR and earlier acrophase compared with tSCI and controls (p < 0.05 in all comparisons). The mean Tcore values during wake and non-rapid eye movement (NREM) and rapid eye movement (REM) sleep stages were higher in cSCI compared with tSCI and controls (p < 0.05). Tcore variability throughout the 24 h differed significantly between cSCI, tSCI, and controls. CONCLUSIONS: cSCI had higher Tcore values without physiological night-time fall compared with controls and tSCI, and a disrupted Tcore circadian rhythm. Furthermore, SCI individuals did not display the physiological state-dependent Tcore modulation. The disconnection of the sympathetic nervous system from its central control caused by the SCI could affect thermoregulation including Tcore modulation during sleep. It is also possible that the reduced representation of deep sleep in people with SCI impairs such ability. Further studies are necessary to evaluate whether improvement of sleep could ameliorate thermoregulation and vice versa.

Performing sleep studies after the COVID-19 outbreak: practical suggestions from Bologna's sleep unit.

The Coronavirus Disease 2019 (COVID-19) pandemic required a thorough re-organization of every sector of the healthcare system. Sleep laboratories need to renew protocols in order to guarantee the safety of patients and healthcare staff while providing exams. Polysomnography (PSG) examinations are essential for the diagnosis and treatment management of several sleep disorders, which may constitute a public or personal safety issue such as obstructive sleep apnea syndrome. Here we provide some practical advice on how to perform sleep studies after the COVID-19 outbreak based on our experience, the review of the existing literature and current national and international recommendations by Health Authorities. We believe that with appropriate precautions it is possible to guarantee a safe restart of PSG and other sleep studies.

Validation of the new index of baroreflex function to identify neurogenic orthostatic hypotension.

BACKGROUND: According to expert opinion, orthostatic hypotension (OH) associated to a change in heart rate (ΔHR) less than 15 bpm suggests neurogenic OH (NOH). Recently, the ratio between HR and systolic blood pressure changes at 3 min of tilt test (ΔHR/ΔSBP) has been proposed as a better index than the ΔHR cut-off of 17 bpm. Our aim was to validate these indexes based on HR in an independent cohort of patients who performed cardiovascular reflex tests according to standardized procedures at our Institution. METHODS: We applied the HR indexes to all cardiovascular reflex tests that fulfilled the following criteria: (1) presence of classical OH at tilt test, (2) reliable Valsalva manoeuvre (VM), (3) absence of heart disease. We classified OH according to VM (absence of overshoot = NOH), and verified how many were correctly identified by ΔHR/ΔSBP (≤0.49 neurogenic) and ΔHR (≤17 and ≤15 neurogenic). RESULTS: We identified 369 tests with OH. Based on VM, 335 were NOH. The ΔHR/ΔSBP ≤ 0.49 identified NOH with a sensitivity of 91% and a specificity of 59%, the ΔHR ≤ 17 bpm with 88% sensitivity and 38% specificity, and the ΔHR ≤ 15 bpm with 84% sensitivity and 50% specificity. CONCLUSION: In our cohort, the ΔHR/ΔSBP ratio had a good sensitivity but a limited specificity to identify NOH. This easily applicable test may represent a valuable screening tool in a clinical setting to identify patients who need further detailed autonomic testing to confirm the neurogenic origin of OH.

Testing cardiovascular autonomic function in the COVID-19 era: lessons from Bologna's Autonomic Unit.

The coronavirus disease 2019 (COVID-19) pandemic has changed the way most medical procedures are performed. Autonomic units, as well as other healthcare sectors, are required to undergo a thorough reorganization of the protocols in order to guarantee the safety of patients and healthcare staff. Cardiovascular autonomic function testing (CAFT) is necessary in certain situations; however, it poses several concerns which need to be addressed. Here, we provide some practical advice based on current national and international health authorities' recommendations and our experience about how to perform CAFT during the COVID-19 emergency. We examine aspects regarding patients, healthcare staff, laboratory preparation, and test performance.

Progression and prognosis in multiple system atrophy presenting with REM behavior disorder.

OBJECTIVES: To investigate (1) the prevalence of REM sleep behavior disorder (RBD) as mode of disease onset in a cohort of patients with multiple system atrophy (MSA) and (2) disease progression and prognosis in patients with MSA with RBD predating (pre-RBD) and following (post-RBD) disease onset. METHODS: We retrospectively identified all patients with a clinical diagnosis of MSA evaluated at least once a year during the disease course. Type of onset was defined by the first reported motor or autonomic symptom/sign related to MSA. The occurrence of symptoms/signs and milestone of disease progression, and their latency from disease onset, were collected. Survival data were calculated. RBD was confirmed by video-polysomnography. RESULTS: Of a total of 158 patients, pre-RBD represented the mode of disease onset in 27% of patients, preceding disease onset according to the international criteria with a median of 3 (2-5) years. Comparing pre-RBD and post-RBD patients, the first group showed an increased prevalence of autonomic onset of disease, a reduced prevalence of parkinsonism, an earlier onset of stridor, pyramidal signs, symptomatic orthostatic hypotension, urinary dysfunction, severe dysphagia, and wheelchair dependency. The risk of death was higher in patients with pre-RBD. CONCLUSIONS: In our MSA cohort, RBD represented the most frequent mode of disease presentation. A more rapid progression of disease was observed in the pre-RBD group. These findings suggested a careful assessment of sleep disorders to early recognize RBD and a closer follow-up of autonomic dysfunction and stridor in patients with pre-RBD.

The natural history of idiopathic autonomic failure: The IAF-BO cohort study.

OBJECTIVE: To retrospectively describe clinical and instrumental features of a cohort of patients with at least a 5-year history of idiopathic autonomic failure (IAF) longitudinally evaluated at the Autonomic Unit of the University of Bologna (IAF-Bo cohort). METHODS: We identified patients with at least a 5-year history of IAF who were referred to our department from 1989 to 2016 and evaluated at least once a year during the disease course. Clinical and instrumental data were collected from medical records. Clinical variables were categorized as early if presenting within 3 years from disease onset. Predictors associated with conversion to other synucleinopathies were identified in a Cox regression analysis. RESULTS: The IAF-Bo cohort included 50 patients (39 male, 19 deceased at the last follow-up). At the last follow-up visit, 34 patients retained IAF phenotype (ncIAF group), while 16 developed a CNS synucleinopathy (converters group). Specific clinical and instrumental features were represented differently in the converters and ncIAF groups. The converters group showed a higher risk of death than the ncIAF group. Early onset of urinary dysfunction, early onset of REM sleep behavior disorder, and a Valsalva ratio ≥1.25 were identified as variables associated with phenoconversion. CONCLUSIONS: This is one of the largest studies on the natural history of a cohort of patients with at least a 5-year history of IAF, showing a percentage of phenoconversion of 32%. We demonstrated that specific clinical and instrumental features entail an increased probability of phenoconversion. These findings could contribute to a better definition of the nature of IAF and to the identification of early markers of phenoconversion.

Iodine-123-meta-iodobenzylguanidine Myocardial Scintigraphy in Isolated Autonomic Failure: Potential Red Flag for Future Multiple System Atrophy.

Pure autonomic failure is challenging as it can be the presenting feature of a central nervous system syncleinopathy such as Parkinson's disease (PD) or multiple system atrophy (MSA). Because the prognosis of MSA and PD is so different, predictive features for a possible conversion can be extremely valuable. In this paper, we report three cases (two with autopsy-proven diagnosis) that had isolated AF for many years before converting to MSA or PD. Of all the tests that were performed during the premotor stage, Iodine-123-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy was predictive of the conversion to MSA. We suggest that MIBG myocardial scintigraphy, when performed in patients with isolated AF, may be a valuable predictor of conversion to MSA. On the contrary, the role of such test in parkinsonian patients irrespective of the presence of AF is still to be clarified.

Physiological Mechanisms Mediating the Coupling between Heart Period and Arterial Pressure in Response to Postural Changes in Humans.

The upright posture strengthens the coupling between heart period (HP) and systolic arterial pressure (SAP) consistently with a greater contribution of the arterial baroreflex to cardiac control, while paradoxically decreasing cardiac baroreflex sensitivity (cBRS). To investigate the physiological mechanisms that mediate the coupling between HP and SAP in response to different postures, we analyzed the cross-correlation functions between low-frequency HP and SAP fluctuations and estimated cBRS with the sequence technique in healthy male subjects during passive head-up tilt test (HUTT, n = 58), during supine wakefulness, supine slow-wave sleep (SWS), and in the seated and active standing positions (n = 8), and during progressive loss of 1 L blood (n = 8) to decrease central venous pressure in the supine position. HUTT, SWS, the seated, and the standing positions, but not blood loss, entailed significant increases in the positive correlation between HP and the previous SAP values, which is the expected result of arterial baroreflex control, compared with baseline recordings in the supine position during wakefulness. These increases were mirrored by increases in the low-frequency variability of SAP in each condition but SWS. cBRS decreased significantly during HUTT, in the seated and standing positions, and after blood loss compared with baseline during wakefulness. These decreases were mirrored by decreases in the RMSSD index, which reflects cardiac vagal modulation. These results support the view that the cBRS decrease associated with the upright posture is a byproduct of decreased cardiac vagal modulation, triggered by the arterial baroreflex in response to central hypovolemia. Conversely, the greater baroreflex contribution to cardiac control associated with upright posture may be explained, at least in part, by enhanced fluctuations of SAP, which elicit a more effective entrainment of HP fluctuations by the arterial baroreflex. These SAP fluctuations may result from enhanced fluctuations of vascular resistance specific to the upright posture, and not be driven by the accompanying central hypovolemia.

Early stridor onset and stridor treatment predict survival in 136 patients with MSA.

OBJECTIVE: To evaluate the predictive value of stridor and its latency of onset and to investigate the role of stridor treatment in a cohort of patients with multiple system atrophy (MSA) referred to a tertiary center. METHODS: We retrospectively identified patients diagnosed with MSA referred to our department beginning in 1991 and evaluated at least yearly during the disease course. Stridor was defined as present when confirmed by a whole night video-polysomnography and as early if presenting within 3 years of disease onset. Survival data, from disease onset to time of death, were calculated with Kaplan-Meier curves. Predictors were identified in univariate and multivariable Cox regression analyses. RESULTS: We included 136 patients with MSA; 113 were deceased at the time of study. Stridor was diagnosed in 42 patients, and 22 presented early stridor onset. Twelve of the 31 patients treated for stridor received tracheostomy, and 19 received continuous positive airway pressure. Overall survival did not differ between patients with and without stridor, while patients with early stridor onset had a worse prognosis than those developing this symptom later. In the stridor subgroup, early stridor onset was an unfavorable survival predictor. Stridor treatment was significantly associated with survival in our population. The Kaplan-Meier curve did not reveal significant differences in survival between the 2 treatments even though there was a trend toward longer disease duration in patients receiving tracheostomy. CONCLUSIONS: Our results demonstrated that early stridor onset is an independent predictor for shorter survival and that tracheostomy could control stridor, influencing disease duration.

A longitudinal study of a family with adult-onset autosomal dominant leukodystrophy: Clinical, autonomic and neuropsychological findings.

BACKGROUND AND PURPOSE: Adult-onset autosomal dominant leukodystrophy (ADLD) is a rare progressive neurological disorder caused by Lamin B1 duplication (LMNB1). Our aim was to investigate longitudinally the pattern of the autonomic dysfunction and the degree of neuropsychological involvement. METHODS: Three related ADLD patients and one asymptomatic carrier of LMNB1 duplication underwent a standardized evaluation of autonomic nervous system, including cardiovascular reflexes, pharmacological testing, microneurography, skin biopsy, Metaiodobenzylguanidine scintigraphy and a complete neuropsychological battery. RESULTS: An early neurogenic orthostatic hypotension was detected in all patients and confirmed by a low rise in noradrenaline levels on Tilt Test. However infusion of noradrenaline resulted in normal blood pressure rise as well as the infusion of clonidine. At the insulin tolerance test the increase in adrenaline resulted pathological in two out three patients. Microneurography failed to detect muscle sympathetic nerve activity bursts. Skin biopsy revealed a poor adrenergic innervation, while cardiac sympathetic nerves were normal. None of ADLD patients showed a global cognitive deficit but a selective impairment in the executive functions. CONCLUSION: Autonomic disorder in ADLD involves selectively the postganglionic sympathetic system including the sympatho-adrenal response. Cognitive involvement consisting in an early impairment of executive tasks that might precede brain MR abnormalities.

A patient with PMP22-related hereditary neuropathy and DBH-gene-related dysautonomia.

Recurrent focal neuropathy with liability to pressure palsies is a relatively frequent autosomal-dominant demyelinating neuropathy linked to peripheral myelin protein 22 (PMP22) gene deletions. The combination of PMP22 gene mutations with other genetic variants is known to cause a more severe phenotype than expected. We present the case of a patient with severe orthostatic hypotension since 12 years of age, who inherited a PMP22 gene deletion from his father. Genetic double trouble was suspected because of selective sympathetic autonomic disturbances. Through exome-sequencing analysis, we identified two novel mutations in the dopamine beta hydroxylase gene. Moreover, with interactome analysis, we excluded a further influence on the origin of the disease by variants in other genes. This case increases the number of unique patients presenting with dopamine-ß-hydroxylase deficiency and of cases with genetically proven double trouble. Finding the right, complete diagnosis is crucial to obtain adequate medical care and appropriate genetic counseling.

Cardiovascular autonomic testing performed with a new integrated instrumental approach is useful in differentiating MSA-P from PD at an early stage.

OBJECTIVE: To evaluate whether a battery of cardiovascular autonomic tests (Ewing's battery, EB) performed with a new integrated instrumental approach is useful in differentiating multiple system atrophy with predominant parkinsonism (MSA-P) from Parkinson's disease (PD) at an early stage. METHODS: We retrospectively analyzed EB tests of all the patients (n = 99) with a parkinsonian syndrome referred to our clinic who performed EB during the first diagnostic workup and were subsequently evaluated at least once a year until a final diagnosis of MSA-P (n = 34) or PD (n = 65). Thirty-eight controls matched for age and sex were included. EB consisted of head-up tilt test (HUTT), Valsalva manoeuvre (VM), deep breathing, and sustained handgrip whose correct execution and results were checked and obtained automatically. Results were compared between groups. Discriminant analysis was performed to identify MSA-P or PD patients. RESULTS: Orthostatic hypotension was found in 22 MSA-P and 3 PD patients. Cardiovascular reflexes indices were significantly more affected in MSA-P compared to PD and controls. EB presented a 91% sensitivity and 94% specificity in the differentiation of MSA-P and PD. HUTT + VM presented a 91% sensitivity and 92% specificity. CONCLUSIONS: Our results suggest that EB or HUTT + VM performed with an integrated instrumental approach and analyzed with the discriminant procedure may distinguish MSA-P from PD at an early stage and might improve the accuracy of current diagnostic criteria. However, a validation in separate samples and prospective studies is needed.

Multiple system atrophy with prolonged survival: is late onset of dysautonomia the clue?

Multiple system atrophy (MSA) is a neurodegenerative disease characterised by cardiovascular autonomic failure and/or urinary dysfunctions, associated with parkinsonism, cerebellar and/or corticospinal signs, usually leading to death after an average of 7 years. We describe the disease course of five patients diagnosed with probable MSA (4 with predominant parkinsonism and 1 with predominant cerebellar ataxia) who survived for more than 15 years and were followed throughout the disease course at our department. Cardiovascular autonomic dysfunction of any severity occurred late (mean latency from disease onset 9.4 ± 5 years) in this subgroup of MSA patients. The time of involvement of the urogenital system was more variable (from 0 to 14 years after disease onset) and manifested with symptoms of storage disorders (urinary urgency, frequency and incontinence) and erectile dysfunction in men. Conversely complains suggestive of urinary voiding dysfunction (incomplete bladder emptying and urinary retention) were not recorded and patients required catheterization only late in the disease course. In conclusion, our study showed that late onset of both cardiovascular autonomic failure and urinary voiding disorders may be positive prognostic factors in MSA irrespective of the MSA subtype.