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Lenka A, Lamotte G, Beach P. Asymptomatic orthostatic hypotension in synucleinopathies: to treat or not to treat? Clin Auton Res 2024; 34:25-29. [PMID: 38079008 DOI: 10.1007/s10286-023-01006-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Accepted: 10/21/2023] [Indexed: 03/17/2024]
Affiliation(s)
- Abhishek Lenka
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Guillaume Lamotte
- Department of Neurology, University of Utah, Salt Lake City, UT, USA.
- Department of Neurology, George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT, USA.
| | - Paul Beach
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA
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Brassard P, Roy MA, Burma JS, Labrecque L, Smirl JD. Quantification of dynamic cerebral autoregulation: welcome to the jungle! Clin Auton Res 2023; 33:791-810. [PMID: 37758907 DOI: 10.1007/s10286-023-00986-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023]
Abstract
PURPOSE Patients with dysautonomia often experience symptoms such as dizziness, syncope, blurred vision and brain fog. Dynamic cerebral autoregulation, or the ability of the cerebrovasculature to react to transient changes in arterial blood pressure, could be associated with these symptoms. METHODS In this narrative review, we go beyond the classical view of cerebral autoregulation to discuss dynamic cerebral autoregulation, focusing on recent advances pitfalls and future directions. RESULTS Following some historical background, this narrative review provides a brief overview of the concept of cerebral autoregulation, with a focus on the quantification of dynamic cerebral autoregulation. We then discuss the main protocols and analytical approaches to assess dynamic cerebral autoregulation, including recent advances and important issues which need to be tackled. CONCLUSION The researcher or clinician new to this field needs an adequate comprehension of the toolbox they have to adequately assess, and interpret, the complex relationship between arterial blood pressure and cerebral blood flow in healthy individuals and clinical populations, including patients with autonomic disorders.
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Affiliation(s)
- Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada.
- Research center of the Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada.
| | - Marc-Antoine Roy
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
- Research center of the Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada
| | - Joel S Burma
- Cerebrovascular Concussion Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Lawrence Labrecque
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
- Research center of the Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Canada
| | - Jonathan D Smirl
- Cerebrovascular Concussion Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
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Zhou G, Zhao X, Lou Z, Zhou S, Shan P, Zheng N, Yu X, Ma L. Impaired Cerebral Autoregulation in Alzheimer's Disease: A Transcranial Doppler Study. J Alzheimers Dis 2020; 72:623-631. [PMID: 31594219 DOI: 10.3233/jad-190296] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Vasculature changes have been observed in Alzheimer's disease (AD). AD-related vascular pathology might impair cerebral autoregulation (CA). OBJECTIVE This study was designed to evaluate CA of AD patients by using transcranial doppler (TCD). METHODS A total of 61 participants were included in the study, including 31 AD patients and 30 controls. The trend curves of cerebral blood flow velocities (CBFV), pulsatility index, and resistance index were obtained using TCD during supine-to-standing posture changes. CA was measured by the changes of CBFV curves during supine-to-standing test. RESULTS There were two spikes named X spike and W spike that appeared in the CBFV curve when the subjects stood abruptly. The slope of the X spike descending branch, the slope of the W spike ascending branch, and the angle between X and W spikes (α angle), showed significant differences between the experimental and control groups (2.34±0.99 versus 3.15±1.61 cm/s2, p = 0.021; 2.31±0.81 versus 3.38±1.18 cm/s2, p < 0.001; and 52.71±20.26 versus 41.4±12.87 degrees, p = 0.012, respectively). ROC analysis showed that AUCαangle is 0.664 (p = 0.028) and that AUCSAB and AUCadjustedSAB are 0.775 and 0.738, respectively (both p < 0.001). CONCLUSIONS Our study demonstrated that supine-to-standing TCD test is a valuable tool for the evaluation of CA in AD patients. Impaired CA in AD patients manifested as decreased efficiency of changes in the CBFV curve. Neurovascular units were involved in the pathogenesis of AD.
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Affiliation(s)
- Guoyu Zhou
- Department of Geriatric Neurology, Qilu Hospital of Shandong University, Jinan, China
| | - Xinjing Zhao
- Department of Geriatric Neurology, Qilu Hospital of Shandong University, Jinan, China
| | - Zhiyin Lou
- Department of Neurology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Shengnian Zhou
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, China
| | - Peiyan Shan
- Department of Geriatric Neurology, Qilu Hospital of Shandong University, Jinan, China
| | - Ning Zheng
- School of Physics, Beijing Institute of Technology, Beijing, China
| | - Xiaolin Yu
- Department of Geriatric Neurology, Qilu Hospital of Shandong University, Jinan, China
| | - Lin Ma
- Department of Geriatric Neurology, Qilu Hospital of Shandong University, Jinan, China
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Indelicato E, Fanciulli A, Poewe W, Antonini A, Pontieri FE, Wenning GK. Cerebral autoregulation and white matter lesions in Parkinson's disease and multiple system atrophy. Parkinsonism Relat Disord 2015; 21:1393-7. [PMID: 26578037 DOI: 10.1016/j.parkreldis.2015.10.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 09/23/2015] [Accepted: 10/29/2015] [Indexed: 11/28/2022]
Abstract
Cerebral autoregulation is a complex homeostatic process which ensures constant brain blood supply, despite continuous blood pressure fluctuations. Recent evidence suggests that in Parkinson's disease (PD) and multiple system atrophy (MSA) this process is maintained in a broadened range of blood pressure values, consistent with an adaptive mechanism to increase tolerance to orthostatic hypotension. In PD and MSA orthostatic hypotension may be accompanied by supine hypertension which has been recently linked with cerebral white matter lesions in these conditions. We hypothesize that cerebral autoregulation adaptation to chronic orthostatic hypotension may be directly related with an increase susceptibility to hypertensive peaks. Evaluation of cerebral autoregulatory behavior may thus represent a novel approach to simultaneously target orthostatic symptoms and silent end-organ damage in alpha-synucleinopathies, with a beneficial impact on cerebrovascular and cognitive outcome.
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Affiliation(s)
- Elisabetta Indelicato
- Department of Neuroscience, Mental Health and Sensory Organs, "Sapienza" University of Rome, Via di Grottarossa 1035, 00189 Rome, Italy; IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179 Rome, Italy.
| | - Alessandra Fanciulli
- Department of Neuroscience, Mental Health and Sensory Organs, "Sapienza" University of Rome, Via di Grottarossa 1035, 00189 Rome, Italy; Department of Neurology, Innsbruck Medical University, Anichstraße 35, 6020 Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Innsbruck Medical University, Anichstraße 35, 6020 Innsbruck, Austria
| | - Angelo Antonini
- IRCCS Ospedale San Camillo, Via Alberoni 70, 30126 Venice, Italy
| | - Francesco E Pontieri
- Department of Neuroscience, Mental Health and Sensory Organs, "Sapienza" University of Rome, Via di Grottarossa 1035, 00189 Rome, Italy; IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179 Rome, Italy
| | - Gregor K Wenning
- Department of Neurology, Innsbruck Medical University, Anichstraße 35, 6020 Innsbruck, Austria
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Fanciulli A, Strano S, Colosimo C, Caltagirone C, Spalletta G, Pontieri FE. The potential prognostic role of cardiovascular autonomic failure in α-synucleinopathies. Eur J Neurol 2012; 20:231-5. [PMID: 22834919 DOI: 10.1111/j.1468-1331.2012.03819.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Accepted: 06/12/2012] [Indexed: 11/29/2022]
Abstract
Cardiovascular autonomic failure is the second most common dysautonomic feature of α-synucleinopathies and has significant impact on daily activities and quality of life. Here we provide a systematic review of cardiovascular autonomic failure in α-synucleinopathies, emphasizing its impact on cognitive functions and disease outcomes. Articles spanning the period between January 1985 and April 2012 were identified from the PubMed database using a keyword-based search. Epidemiological studies highlight the negative prognostic effect of cardiovascular autonomic failure on cardiovascular and cerebrovascular outcomes and overall mortality in all α-synucleinopathies. Altered cerebral perfusion, vascular pressure stress, and related disruption of the blood-brain barrier may also contribute to the white matter hyperintensities and cognitive dysfunction frequently found in patients affected by neurocardiovascular instability. These findings support the hypothesis that cardiovascular autonomic failure may play a negative prognostic role in α-synucleinopathies and suggest that precocious screening and therapeutic management of cardiovascular autonomic failure may positively impact disease course.
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Affiliation(s)
- A Fanciulli
- Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy
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Périard D, Rey MA, Casagrande D, Vesin JM, Carrera E, Hayoz D. The effect of valsartan versus non-RAAS treatment on autoregulation of cerebral blood flow. Cerebrovasc Dis 2012; 34:78-85. [PMID: 22814178 DOI: 10.1159/000338777] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 04/12/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Cerebral autoregulation (CA) is a protective mechanism which maintains the steadiness of the cerebral blood flow (CBF) through a broad range of systemic blood pressure (BP). Acute hypertension has been shown to reduce the cerebrovascular adaptation to BP variations. However, it is still unknown whether CA is impaired in chronic hypertension. This study evaluated whether a strict control of BP affects the CA in patients with chronic hypertension, and compared a valsartan-based regimen to a regimen not inhibiting the renin-angiotensin-aldosterone system (non-RAAS). METHODS Eighty untreated patients with isolated systolic hypertension were randomized to valsartan 320 mg or to a non-RAAS regimen during 6 months. The medication was upgraded to obtain BP <140/90 mm Hg. Continuous recordings of arterial BP and CBF velocity (transcranial Doppler) were performed during periods of 5 minutes, at rest, and at different levels of alveolar CO(2) pressure provided by respiratory maneuvers. The dominant frequency of CBF oscillations was determined for each patient. Dynamic CA was measured as the mean phase shift between BP and CBF by cross-spectral analysis in the medium frequency and in the dominant CBF frequency. RESULTS Mean ambulatory 24-hour BP fell from 144/87 to 127/79 mm Hg in the valsartan group and from 144/87 to 134/81 mm Hg in the non-RAAS group (p = 0.13). Both groups had a similar reduction in the central BP and in the carotido-femoral pulse wave velocity. The average phase shift between BP fluctuations and CBF response at rest was normal at randomization (1.82 ± 0.08 s), which is considered a preserved autoregulation and increased to 1.91 ± 0.12 s at the end of study (p = 0.45). The comparison of both treatments showed no significant difference (-0.01 ± 0.17 s vs. 0.16 ± 0.16 s, p = 0.45) for valsartan versus non-RAAS groups. The plasmatic level of glycosylated hemoglobin decreased in the valsartan arm compared to the non-RAAS arm (-0.23 ± 0.06 vs. -0.08 ± 0.07%, p = 0.07). CONCLUSIONS In elderly hypertensive men with isolated chronic systolic hypertension, CA seems efficient at baseline and is not significantly affected by 6 months of BP-lowering treatment. This suggests that the preventive effects of BP medication against stroke are not mediated through a restoration of the CA.
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Affiliation(s)
- Daniel Périard
- Department of Internal Medicine and Angiology, Hôpital Cantonal, Fribourg, Switzerland
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Ojha A, McNeeley K, Heller E, Alshekhlee A, Chelimsky G, Chelimsky TC. Orthostatic syndromes differ in syncope frequency. Am J Med 2010; 123:245-9. [PMID: 20193833 DOI: 10.1016/j.amjmed.2009.09.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Revised: 09/03/2009] [Accepted: 09/04/2009] [Indexed: 11/30/2022]
Abstract
BACKGROUND There are conflicting opinions on whether postural tachycardia syndrome predisposes to syncope. We investigated this relationship by comparing the frequency of syncope in postural tachycardia syndrome and orthostatic hypotension. METHODS We queried our autonomic laboratory database of 3700 patients. Orthostatic hypotension and postural tachycardia syndrome were defined in standard fashion, except that postural tachycardia syndrome required the presence of orthostatic symptoms and a further increase in heart rate beyond 10 minutes. Syncope was defined as an abrupt decrease in blood pressure and often, heart rate, requiring termination of the tilt study. Statistical analysis utilized Fisher's exact test and Student's t test, as appropriate. RESULTS Of 810 patients referred for postural tachycardia syndrome, 185 met criteria while another 328 patients had orthostatic hypotension. Of the postural tachycardia syndrome patients, 38% had syncope on head-up tilt, compared with only 22% of those with orthostatic hypotension (P<.0001). In the postural tachycardia group, syncope on head-up tilt was associated with a clinical history of syncope in 90%, whereas absence of syncope on head-up tilt was associated with a clinical history of syncope in 30% (P<.0001). In contrast, syncope on head-up tilt did not bear any relationship to clinical history of syncope in the orthostatic hypotension group (41% vs 36%; P=.49). CONCLUSION Our results demonstrate that syncope (both tilt table and clinical) occurs far more commonly in patients who have postural tachycardia syndrome than in patients with orthostatic hypotension. These findings suggest that one should be clinically aware of the high risk of syncope in patients with postural tachycardia syndrome, and the low-pressure baroreceptor system that is implicated in postural tachycardia syndrome might confer more sensitivity to syncope than the high pressure system implicated in orthostatic hypotension.
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Affiliation(s)
- Ajitesh Ojha
- Neurologic Institute, University Hospitals Case Medical Center, Cleveland, Ohio 44106, USA
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Arbogast SD, Alshekhlee A, Hussain Z, McNeeley K, Chelimsky TC. Hypotension unawareness in profound orthostatic hypotension. Am J Med 2009; 122:574-80. [PMID: 19486719 DOI: 10.1016/j.amjmed.2008.10.040] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 09/29/2008] [Accepted: 10/13/2008] [Indexed: 11/29/2022]
Abstract
BACKGROUND Clinicians depend on history given by the patients when considering the diagnosis of orthostatic hypotension. METHODS Patients with a decrease in systolic blood pressure more than 60 mm Hg from baseline during a head-up tilt table test were included. They were classified according to their symptoms during the head-up tilt table test. Localization of the cause of orthostatic hypotension was sought in each of these groups. RESULTS Eighty-eight (43%) patients had typical symptoms, 49 (24%) had atypical symptoms, and 68 (33%) were asymptomatic. The average decrease in systolic blood pressure was 88 mm Hg, 87.5 mm Hg, and 89.8 mm Hg in the typical, atypical, and asymptomatic groups, respectively (P=.81). Patients reported severe dizziness with a similar frequency as lower extremity discomfort. Backache and headache also were common atypical complaints. Patients with peripheral cause of dysautonomia were able to sustain the longest upright position during the head-up tilt table test (21 minutes, compared with central dysautonomia [15 minutes]) (P=.005). There was no correlation between the cause of dysautonomia and the occurrence of symptoms during the head-up tilt table test (P=.58). CONCLUSION A third of the patients with severe orthostatic hypotension are completely asymptomatic during the head-up tilt table test, and another quarter have atypical complaints that would not lead physicians toward the diagnosis of orthostatic hypotension. These findings suggest that they might not provide adequate information in diagnosing profound orthostatic hypotension in a subset of patients with this disorder.
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Affiliation(s)
- Steven D Arbogast
- Autonomic Laboratory, Neurologic Institute, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, Ohio 44106, USA.
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Xu WH, Wang H, Wang B, Niu FS, Gao S, Cui LY. Disparate cardio-cerebral vascular modulation during standing in multiple system atrophy and Parkinson disease. J Neurol Sci 2009; 276:84-7. [PMID: 18849054 DOI: 10.1016/j.jns.2008.09.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2008] [Revised: 09/02/2008] [Accepted: 09/03/2008] [Indexed: 11/17/2022]
Affiliation(s)
- Wei-Hai Xu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Shuaifuyuan 1, Beijing, China.
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Abstract
BACKGROUND It has been almost 4 decades since the descriptions of the 3 parts of multiple system atrophy (MSA) have taken place, characterized clinically by dysautonomia, parkinsonism, and cerebellar dysfunction. The discovery of a distinctive pathologic maker has finally provided the conceptual synthesis of these 3 entities into the universal designation of MSA as a distinct disease process with a complex combination of clinical presentations. Although advances have been made in terms of awareness and knowledge concerning the clinical features and pathophysiology of MSA, it remains challenging for neurologists who treat these patients to differentiate MSA from its mimics as well as providing them with effective treatment. REVIEW SUMMARY The aim of this review is to provide an overview of the advances in the knowledge of the disease, to highlight typical features useful for the recognition of its entity, and to enlist different treatment options. CONCLUSION Despite the fact that there is still no treatment modality that can alter the disease progression, a number of useful symptomatic treatment measures are available and should be offered to patients to ameliorate the nonmotor features of MSA and even the motor features that may at least transiently respond to treatment.
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Suzuki K, Asahina M, Suzuki A, Hattori T. Cerebral oxygenation monitoring for detecting critical cerebral hypoperfusion in patients with multiple system atrophy during the head-up tilt test. Intern Med 2008; 47:1681-7. [PMID: 18827416 DOI: 10.2169/internalmedicine.47.1094] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE Near infrared spectroscopy (NIRS) is a non-invasive optical technique to monitor cerebral tissue oxygen saturation (ScO(2)). The purpose of this study was to reveal the usefulness of ScO(2) monitoring in evaluating cerebral circulation in patients with autonomic failure. METHODS Nineteen patients with multiple system atrophy (MSA), who had autonomic failure, and 10 age-matched normal control subjects participated. In addition to blood pressure monitoring, ScO(2) was recorded by a near-infrared spectroscopy instrument during head-up tilt (HUT) test. RESULTS HUT tests induced postural symptoms in 9 MSA patients (presyncopal group), but not in 10 MSA patients (non-presyncopal group) or in any of the controls. ScO(2), which decreased slightly in the controls and MSA patients, did not differ significantly between the MSA and control groups. With regard to MSA subgroups, the ScO(2) reduction in the presyncopal group (-3.1+/-1.7%) was significantly larger than in the non-presyncopal group (-0.9+/-0.5%, P<0.005) and controls (-1.1+/-1.0%, P<0.05). The systolic blood pressure decreases during HUT in the non-presyncopal (-35.2+/-16.1 mmHg, P<0.01) and presyncopal (-54.3+/-27.5 mmHg, P<0.0005) groups were significantly greater than that in the control group (4.0+/-10.7 mmHg), but the difference between presyncopal and non-presyncopal groups was not significant. CONCLUSION In our study, ScO(2) reduction seemed to be associated with presyncopal symptoms. ScO(2) monitoring may be useful to detect cerebral hypoperfusion in MSA patients with autonomic failure.
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Affiliation(s)
- Koji Suzuki
- Department of Neurology, Chiba University Graduate School of Medicine
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Ozawa T. Morphological substrate of autonomic failure and neurohormonal dysfunction in multiple system atrophy: impact on determining phenotype spectrum. Acta Neuropathol 2007; 114:201-11. [PMID: 17593377 DOI: 10.1007/s00401-007-0254-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 06/06/2007] [Accepted: 06/07/2007] [Indexed: 01/25/2023]
Abstract
Autonomic failure is a prominent clinical feature of patients with multiple system atrophy (MSA). Neurohormonal dysfunction is also a frequent accompaniment in patients with MSA. The determination of the pathological involvement of the autonomic neurons, which are responsible for circadian rhythms and responses to stress, provides new insight into autonomic failure and neurohormonal dysfunction in MSA. The disruptions of circadian rhythms and responses to stress may underlie the impairment of homeostatic integration responsible for cardiovascular and respiratory failures. These notions lead to the hypothesis that a pathological involvement of autonomic neurons is a significant factor of the poor prognosis of MSA. Beyond this perspective, endeavors to find the morphological phenotype that represents a predominant loss of autonomic neurons may elucidate the full spectrum of pathological involvements in MSA.
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Affiliation(s)
- Tetsutaro Ozawa
- Department of Neurology, Niigata University Brain Research Institute, 1 Asahimachi, Niigata, 951-8585, Japan.
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