1
|
Soh JH, Kang YJ, Yoon WH, Park CS, Shin HW. Positional Obstructive Sleep Apnea and Periodic Limb Movements During Sleep: A Large Multicenter Study. Clin Exp Otorhinolaryngol 2024; 17:217-225. [PMID: 38693650 PMCID: PMC11375175 DOI: 10.21053/ceo.2024.00034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 04/29/2024] [Indexed: 05/03/2024] Open
Abstract
OBJECTIVES The relationships among positional obstructive sleep apnea (POSA), obstructive sleep apnea (OSA), and periodic limb movements during sleep (PLMS) remain unclear. We investigated these relationships with respect to the severity of OSA and explored the underlying mechanisms. METHODS We retrospectively reviewed 6,140 eligible participants who underwent full-night diagnostic polysomnography at four clinical centers over a 5-year period, utilizing event-synchronized analysis. We evaluated the periodic limb movement index (PLMI) and the periodic limb movement with arousal index (PLMAI). The impacts of POSA on the PLMI, PLMAI, and PLMS were analyzed in relation to the severity of OSA. RESULTS The mean PLMI, the mean PLMAI, and the prevalence of PLMS were significantly lower in participants with severe OSA compared to the mild and moderate OSA groups. The mean PLMI among those with mild OSA exceeded that of control participants. Furthermore, the mean PLMI (4.8±12.7 vs. 2.6±9.8 events/hr, P<0.001), the mean PLMAI (0.9±3.7 vs. 0.5±3.3 events/hr, P<0.001), and the prevalence of PLMS (11% vs. 5.3%, P<0.001) were higher in patients with POSA than in those with non-positional OSA. This PLMS finding was particularly pronounced among those with severe OSA (odds ratio [OR], 1.554; 95% confidence interval [CI], 1.065-2.267) and was less evident in the mild (OR, 0.559; 95% CI, 0.303-1.030) and moderate (OR, 1.822; 95% CI, 0.995-3.339) groups. CONCLUSION Patients with POSA, especially those with severe OSA, exhibit a comparatively high prevalence of PLMS. In cases involving prominent PLMS, the diagnosis and treatment of POSA and OSA should be considered.
Collapse
Affiliation(s)
- Jae Hyun Soh
- Seoul National University College of Medicine, Seoul, Korea
| | - Yun Jin Kang
- Department of Otorhinolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Cheonan, Korea
| | | | - Chan-Soon Park
- Department of Otorhinolaryngology-Head and Neck Surgery, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Korea
| | - Hyun-Woo Shin
- OUaR LaB Inc., Seoul, Korea
- Department of Pharmacology, Seoul National University College of Medicine, Seoul, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul, Korea
- Sensory Organ Research Institute, Seoul National University College of Medicine, Seoul, Korea
| |
Collapse
|
2
|
Riccardi S, Ferri R, Garbazza C, Miano S, Manconi M. Pharmacological responsiveness of periodic limb movements in patients with restless legs syndrome: a systematic review and meta-analysis. J Clin Sleep Med 2023; 19:811-822. [PMID: 36692194 PMCID: PMC10071388 DOI: 10.5664/jcsm.10440] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 12/06/2022] [Accepted: 12/06/2022] [Indexed: 01/25/2023]
Abstract
STUDY OBJECTIVES Periodic limb movements during sleep (PLMS) are a frequent finding in restless legs syndrome, but their impact on sleep is still debated, as well the indication for treatment. We systematically reviewed the available literature to describe which drug categories are effective in suppressing PLMS, assessing their efficacy through a meta-analysis, when this was possible. METHODS The review protocol was preregistered on PROSPERO (CRD42021175848), and the systematic search was conducted on and EMBASE (last searched on March 2020). We included original human studies, which assessed PLMS modification on drug treatment with a full-night polysomnography, through surface electrodes on each tibialis anterior muscle. When at least 4 studies were available on the same drug or drug category, we performed a random-effect model meta-analysis. RESULTS Dopamine agonists like pramipexole and ropinirole resulted the most effective, followed by l-dopa and other dopamine agonists. Alpha2delta ligands are moderately effective as well opioids, despite available data on these drugs are much more limited than those on dopaminergic agents. Valproate and carbamazepine did not show a significant effect on PLMS. Clonazepam showed contradictory results. Perampanel and dypiridamole showed promising but still insufficient data. The same applies to iron supplementation. CONCLUSIONS Dopaminergic agents are the most powerful suppressors of PLMS. However, most therapeutic trials in restless legs syndrome do not report objective polysomnographic findings, there is a lack of uniformity in presenting results on PLMS. Longitudinal polysomnographic interventional studies, using well-defined and unanimous scoring criteria and endpoints on PLMS are needed. CITATION Riccardi S, Ferri R, Garbazza C, Miano S, Manconi M. Pharmacological responsiveness of periodic limb movements in patients with restless legs syndrome: a systematic review and meta-analysis. J Clin Sleep Med. 2023;19(4):811-822.
Collapse
Affiliation(s)
- Silvia Riccardi
- Sleep Medicine Unit, Regional Hospital of Lugano, Neurocenter of Southern Switzerland, Lugano, Switzerland
| | - Raffaele Ferri
- Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy
| | - Corrado Garbazza
- Sleep Medicine Unit, Regional Hospital of Lugano, Neurocenter of Southern Switzerland, Lugano, Switzerland
| | - Silvia Miano
- Sleep Medicine Unit, Regional Hospital of Lugano, Neurocenter of Southern Switzerland, Lugano, Switzerland
| | - Mauro Manconi
- Sleep Medicine Unit, Regional Hospital of Lugano, Neurocenter of Southern Switzerland, Lugano, Switzerland
| |
Collapse
|
3
|
DelRosso LM, Mogavero MP, Bruni O, Schenck CH, Fickenscher A, Ferri R. Trazodone affects periodic leg movements and chin muscle tone during sleep less than selective serotonin reuptake inhibitor antidepressants in children. J Clin Sleep Med 2022; 18:2829-2836. [PMID: 35975551 PMCID: PMC9713918 DOI: 10.5664/jcsm.10242] [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: 03/04/2022] [Revised: 08/09/2022] [Accepted: 08/10/2022] [Indexed: 12/14/2022]
Abstract
STUDY OBJECTIVES To test the hypothesis that children taking trazodone have less leg movements during sleep (LMS) and higher rapid eye movement (REM) sleep atonia than children taking selective serotonin reuptake inhibitors (SSRIs) but more than normal controls. METHODS Fifteen children (9 girls and 6 boys, mean age 11.7 years, standard deviation [SD] 3.42) taking trazodone (median dosage 50 mg/d, range 25-200 mg) for insomnia and 19 children (11 girls and 8 boys, mean age 13.7 years, SD 3.07) taking SSRIs for depression, anxiety, or both were consecutively recruited, as well as an age- and sex-matched group of 25 control children (17 girls and 8 boys, mean age 13.7 years, SD 3.11). LMS were scored and a series of parameters was calculated, along with the analysis of their time structure. The Atonia Index was then computed for each non-REM sleep stage and for REM sleep. RESULTS Children taking trazodone exhibited slightly higher leg movement indices than controls but lower than those found in children taking SSRIs and their time structure was different. Chin electromyogram atonia in all sleep stages was not significantly altered in children taking trazodone but was decreased in children taking SSRIs, especially during non-REM sleep. CONCLUSIONS In children, SSRIs but not trazodone are associated with a significantly increased number of LMS, including periodic LMS, and increased chin tone in all sleep stages. The assessment of periodic limb movement disorder and REM sleep without atonia might not be accurate when children are taking SSRIs because of their significant impact. CITATION DelRosso LM, Mogavero MP, Bruni O, Schenck CH, Fickenscher A, Ferri R. Trazodone affects periodic leg movements and chin muscle tone during sleep less than selective serotonin reuptake inhibitor antidepressants in children. J Clin Sleep Med. 2022;18(12):2829-2836.
Collapse
Affiliation(s)
- Lourdes M. DelRosso
- Seattle Children’s Hospital and University of Washington, Seattle, Washington
| | - Maria P. Mogavero
- Institute of Molecular Bioimaging and Physiology, National Research Council, Milan, Italy
- Sleep Disorders Center, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Oliviero Bruni
- Department of Social and Developmental Psychology, Sapienza University, Rome, Italy
| | - Carlos H. Schenck
- Minnesota Regional Sleep Disorders Center, Department of Psychiatry, Hennepin County Medical Center, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Amy Fickenscher
- Seattle Children’s Hospital and University of Washington, Seattle, Washington
| | - Raffaele Ferri
- Sleep Research Centre, Oasi Research Institute–IRCCS, Troina, Italy
| |
Collapse
|
4
|
Parrino L, Halasz P, Szucs A, Thomas RJ, Azzi N, Rausa F, Pizzarotti S, Zilioli A, Misirocchi F, Mutti C. Sleep medicine: Practice, challenges and new frontiers. Front Neurol 2022; 13:966659. [PMID: 36313516 PMCID: PMC9616008 DOI: 10.3389/fneur.2022.966659] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Sleep medicine is an ambitious cross-disciplinary challenge, requiring the mutual integration between complementary specialists in order to build a solid framework. Although knowledge in the sleep field is growing impressively thanks to technical and brain imaging support and through detailed clinic-epidemiologic observations, several topics are still dominated by outdated paradigms. In this review we explore the main novelties and gaps in the field of sleep medicine, assess the commonest sleep disturbances, provide advices for routine clinical practice and offer alternative insights and perspectives on the future of sleep research.
Collapse
Affiliation(s)
- Liborio Parrino
- Department of General and Specialized Medicine, Sleep Disorders Center, University Hospital of Parma, Parma, Italy
- *Correspondence: Liborio Parrino
| | - Peter Halasz
- Szentagothai János School of Ph.D Studies, Clinical Neurosciences, Semmelweis University, Budapest, Hungary
| | - Anna Szucs
- Department of Behavioral Sciences, National Institute of Clinical Neurosciences, Semmelweis University, Budapest, Hungary
| | - Robert J. Thomas
- Division of Pulmonary, Critical Care and Sleep, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Nicoletta Azzi
- Department of General and Specialized Medicine, Sleep Disorders Center, University Hospital of Parma, Parma, Italy
| | - Francesco Rausa
- Department of General and Specialized Medicine, Sleep Disorders Center, University Hospital of Parma, Parma, Italy
- Department of Medicine and Surgery, Unit of Neurology, University of Parma, Parma, Italy
| | - Silvia Pizzarotti
- Department of General and Specialized Medicine, Sleep Disorders Center, University Hospital of Parma, Parma, Italy
| | - Alessandro Zilioli
- Department of Medicine and Surgery, Unit of Neurology, University of Parma, Parma, Italy
| | - Francesco Misirocchi
- Department of Medicine and Surgery, Unit of Neurology, University of Parma, Parma, Italy
| | - Carlotta Mutti
- Department of General and Specialized Medicine, Sleep Disorders Center, University Hospital of Parma, Parma, Italy
- Department of Medicine and Surgery, Unit of Neurology, University of Parma, Parma, Italy
| |
Collapse
|
5
|
Ouyang F, Wang M, Liao M, Lan L, Liu X, Li H, Mo R, Shi L, Fan Y. Association between periodic limb movements during sleep and neuroimaging features of cerebral small vessel disease: A preliminary cross‐sectional study. J Sleep Res 2022; 31:e13573. [DOI: 10.1111/jsr.13573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/11/2022] [Accepted: 02/13/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Fubing Ouyang
- Department of Neurology National Key Clinical Department and Key Discipline of Neurology The First Affiliated Hospital Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases Sun Yat‐sen University Guangzhou China
| | - Meng Wang
- Department of Radiology The First Affiliated Hospital Sun Yat‐sen University Guangzhou China
| | - Mengshi Liao
- Department of Neurology National Key Clinical Department and Key Discipline of Neurology The First Affiliated Hospital Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases Sun Yat‐sen University Guangzhou China
| | - Linfan Lan
- Department of Neurology National Key Clinical Department and Key Discipline of Neurology The First Affiliated Hospital Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases Sun Yat‐sen University Guangzhou China
| | - Xiaolu Liu
- Department of Neurology National Key Clinical Department and Key Discipline of Neurology The First Affiliated Hospital Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases Sun Yat‐sen University Guangzhou China
| | - Hao Li
- Department of Neurology National Key Clinical Department and Key Discipline of Neurology The First Affiliated Hospital Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases Sun Yat‐sen University Guangzhou China
| | - Rong Mo
- Department of Neurology National Key Clinical Department and Key Discipline of Neurology The First Affiliated Hospital Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases Sun Yat‐sen University Guangzhou China
| | - Lin Shi
- Department of Imaging and Interventional Radiology The Chinese University of Hong Kong Hong Kong China
| | - Yuhua Fan
- Department of Neurology National Key Clinical Department and Key Discipline of Neurology The First Affiliated Hospital Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases Sun Yat‐sen University Guangzhou China
| |
Collapse
|
6
|
Drakatos P, Olaithe M, Verma D, Ilic K, Cash D, Fatima Y, Higgins S, Young AH, Chaudhuri KR, Steier J, Skinner T, Bucks R, Rosenzweig I. Periodic limb movements during sleep: a narrative review. J Thorac Dis 2022; 13:6476-6494. [PMID: 34992826 PMCID: PMC8662505 DOI: 10.21037/jtd-21-1353] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 10/20/2021] [Indexed: 01/02/2023]
Abstract
Objective Using narrative review techniques, this paper evaluates the evidence for separable underlying patho-mechanisms of periodic limb movements (PLMs) to separable PLM motor patterns and phenotypes, in order to elucidate potential new treatment modalities. Background Periodic limb movement disorder (PLMD) is estimated to occur in 5–8% of the paediatric population and 4–11% of the general adult population. Due to significant sleep fragmentation, PLMD can lead to functional impairment, including hyperactivity and delayed language development in children, and poor concentration and work performance in adults. Longitudinal data demonstrate that those with PLMD are at greater risk of depression and anxiety, and a 4-fold greater risk of developing dementia. PLMD has been extensively studied over the past two decades, and several key insights into the genetic, pathophysiological, and neural correlates have been proposed. Amongst these proposals is the concept of separable PLM phenotypes, proposed on the basis of nocturnal features such as the ratio of limb movements and distribution throughout the night. PLM phenotype and presentation, however, varies significantly depending on the scoring utilized and the nocturnal features examined, across age, and co-morbid clinical conditions. Furthermore, associations between these phenotypes with major neurologic and psychiatric disorders remain controversial. Methods In order to elucidate potential divergent biological pathways that may help clarify important new treatment modalities, this paper utilizes narrative review and evaluates the evidence linking PLM motor patterns and phenotypes with hypothesised underlying patho-mechanisms. Distinctive, underlying patho-mechanisms include: a pure motor mechanism originating in the spinal cord, iron deficiency, dopamine system dysfunction, thalamic glutamatergic hyperactivity, and a more cortical-subcortical interplay. In support of the latter hypothesis, PLM rhythmicity appears tightly linked to the microarchitecture of sleep, not dissimilarly to the apnoeic/hypopneic events seen in obstructive sleep apnea (OSA). Conclusions This review closes with a proposal for greater investigation into the identification of potential, divergent biological pathways. To do so would require prospective, multimodal imaging clinical studies which may delineate differential responses to treatment in restless legs syndrome (RLS) without PLMS and PLMS without RLS. This could pave the way toward important new treatment modalities.
Collapse
Affiliation(s)
- Panagis Drakatos
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK.,Sleep Disorders Centre, Guy's and St Thomas' Hospital, GSTT NHS, London, UK.,Faculty of Life and Sciences Medicine, King's College London, London, UK
| | - Michelle Olaithe
- School of Psychological Science, University of Western Australia, Perth, Western Australia, Australia
| | - Dhun Verma
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK
| | - Katarina Ilic
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK.,BRAIN, Imaging Centre, CNS, King's College London, London, UK
| | - Diana Cash
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK.,BRAIN, Imaging Centre, CNS, King's College London, London, UK
| | - Yaqoot Fatima
- Institute for Social Science Research, University of Queensland, Brisbane, Australia.,Centre for Rural and Remote Health, James Cook University, Mount Isa, Australia
| | - Sean Higgins
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK.,Sleep Disorders Centre, Guy's and St Thomas' Hospital, GSTT NHS, London, UK
| | - Allan H Young
- School of Academic Psychiatry, King's College London, London, UK
| | - K Ray Chaudhuri
- King's College London and Parkinson's Foundation Centre of Excellence, King's College Hospital, London, UK
| | - Joerg Steier
- Sleep Disorders Centre, Guy's and St Thomas' Hospital, GSTT NHS, London, UK.,Faculty of Life and Sciences Medicine, King's College London, London, UK
| | - Timothy Skinner
- Institute of Psychology, University of Copenhagen, Copenhagen, Denmark.,La Trobe Rural Health School, La Trobe University, Bendigo, Victoria, Australia
| | - Romola Bucks
- School of Psychological Science, University of Western Australia, Perth, Western Australia, Australia.,The Raine Study, University of Western Australia, Perth, Australia
| | - Ivana Rosenzweig
- Sleep and Brain Plasticity Centre, CNS, IoPPN, King's College London, London, UK.,Sleep Disorders Centre, Guy's and St Thomas' Hospital, GSTT NHS, London, UK
| |
Collapse
|
7
|
Wang Q, Li Y, Li J, Wang J, Shen J, Wu H, Guo K, Chen R. Low Arousal Threshold: A Potential Bridge Between OSA and Periodic Limb Movements of Sleep. Nat Sci Sleep 2021; 13:229-238. [PMID: 33658878 PMCID: PMC7917361 DOI: 10.2147/nss.s292617] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/25/2021] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE Periodic Limb Movements of Sleep (PLMS) is a poorly understood comorbidity with close association to Obstructive Sleep Apnea (OSA). The mechanistic link between the two is unclear. Recent studies on the latter have uncovered low respiratory arousal threshold as an important non-anatomical cause of the disorder. This study sought to investigate whether periodic limb movements are associated with the low respiratory arousal threshold (ArTH) in OSA. METHODS Retrospective data on 720 OSA patients (mean age = 47.0) who underwent Polysomnography (PSG) were collected. Using PLMS diagnostic criteria of PLMS index ≥ 15, patients were divided into the OSA-PLMS group (n=95) and the OSA-only group (n=625). Binary logistic regression analysis was used to examine the correlation between PLMS and the presence of low ArTH, classified using a predicted tool (developed by Edward et al) requiring meeting at least two of the three criteria: apnea-hypopnea index (AHI) < 30/h, nadir oxygen saturation (SaO2) > 82.5%, and fraction of hypopneas > 58.3%. The resulting model was validated in the external MrOS database. RESULTS The patients in the OSA-PLMS group tend to be older, with a higher prevalence of hypertension, diabetes, and stroke. PLMS was associated with age, diabetes, oxygen desaturation index, and low respiratory arousal threshold (OR=8.78 (4.73-16.30), p<0.001). When validated against the MrOS database, low ArTH remained a significant predictor of PLMS with an odds ratio of 1.33 (1.08-1.64, p = 0.009). CONCLUSION This is the first study that demonstrated a strong correlation between PLMS and low respiratory arousal threshold. This suggests a possible mechanistic link between the physical manifestation of PLMS and the non-anatomical low arousal threshold phenotype in OSA.
Collapse
Affiliation(s)
- Qiaojun Wang
- Sleep Center, Respiratory Department, The Second Affiliated Hospital of the Soochow University, Suzhou, People's Republic of China.,Sleep Center, Neurology Department, The Second Affiliated Hospital of the Soochow University, Suzhou, People's Republic of China
| | - Yezhou Li
- School of Medicine, The University of Manchester, Manchester, UK
| | - Jie Li
- Sleep Center, Neurology Department, The Second Affiliated Hospital of the Soochow University, Suzhou, People's Republic of China
| | - Jing Wang
- Sleep Center, Respiratory Department, The Second Affiliated Hospital of the Soochow University, Suzhou, People's Republic of China
| | - Jiucheng Shen
- Sleep Center, Respiratory Department, The Second Affiliated Hospital of the Soochow University, Suzhou, People's Republic of China
| | - Huaman Wu
- Sleep Center, Respiratory Department, The Second Affiliated Hospital of the Soochow University, Suzhou, People's Republic of China
| | - Kaida Guo
- Sleep Center, Respiratory Department, The Second Affiliated Hospital of the Soochow University, Suzhou, People's Republic of China
| | - Rui Chen
- Sleep Center, Respiratory Department, The Second Affiliated Hospital of the Soochow University, Suzhou, People's Republic of China.,Sleep Center, Neurology Department, The Second Affiliated Hospital of the Soochow University, Suzhou, People's Republic of China
| |
Collapse
|
8
|
Jha A, Banerjee N, Feltch C, Robucci R, Earley CJ, Lam J, Allen R. Pilot study: can machine learning analyses of movement discriminate between leg movements in sleep (LMS) with vs. without cortical arousals? Sleep Breath 2020; 25:373-379. [DOI: 10.1007/s11325-020-02100-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/26/2020] [Accepted: 05/01/2020] [Indexed: 11/24/2022]
|
9
|
May AM, May RD, Bena J, Wang L, Monahan K, Stone KL, Barrett-Connor E, Koo BB, Winkelman JW, Redline S, Mittleman MA, Mehra R. Individual periodic limb movements with arousal are temporally associated with nonsustained ventricular tachycardia: a case-crossover analysis. Sleep 2020; 42:5533205. [PMID: 31585012 DOI: 10.1093/sleep/zsz165] [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] [Received: 03/19/2019] [Revised: 05/30/2019] [Indexed: 11/12/2022] Open
Abstract
STUDY OBJECTIVES Both periodic limb movements during sleep (PLMS) and arousals are associated with sympathetic nervous system activation and may be arrhythmogenic. We hypothesize a temporal relationship exists between individual PLMS, particularly with arousal, and nonsustained ventricular tachycardia (NSVT) events. METHODS A bidirectional time-stratified case-crossover design was used to assess temporal associations between PLMS and NSVT during sleep in 49 Osteoporotic Fractures in Men Sleep Study participants with NSVT in a community-based cohort (n = 2,911). Sleep time was divided into approximate 30-min segments. For each NSVT (n = 141), we selected a preceding 30-s hazard period and three randomly chosen 30-s control periods from sleep within the same segment and evaluated for PLMS, respiratory events, minimum saturation, and arousals. Odds ratios and 95% confidence intervals-OR (95% CI)-were determined by conditional logistic regression; covariates included EEG arousals, minimum saturation, and respiratory events in the same hazard/control period. RESULTS Participants with NSVT were 79.5 ± 6.2 years with a PLMS index of 32.1 (IQR: 10.1, 61.4) and apnea-hypopnea index of 17.1 (IQR: 9.4, 26.1). PLMS without arousal were not significantly associated with NSVT (OR = 0.80, 95% CI: 0.41-1.59). PLMS with arousal were associated with NSVT in unadjusted analyses (OR = 2.50, 95% CI: 1.11-5.65) and after adjustment (OR = 2.31, 95% CI: 1.02-5.25). Arousals associated with PLMS were associated with NSVT in unadjusted (OR = 2.84, 95% CI: 1.23-6.56) and adjusted analyses (OR = 2.61, 95% CI: 1.13-6.05). CONCLUSIONS PLMS with (but not without) arousals are temporally associated with a greater than twofold higher odds of subsequent NSVT episodes. PLMS-related arousals may be physiologically important ventricular arrhythmia triggers. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, NCT00070681.
Collapse
Affiliation(s)
- Anna M May
- Sleep Medicine Section, Louis Stokes Cleveland VA Medical Center, Cleveland, OH
| | - Ryan D May
- Department of Engineering, Case Western Reserve University, Cleveland, OH
| | - James Bena
- Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, OH
| | - Lu Wang
- Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, OH
| | - Ken Monahan
- Division of Cardiology, Vanderbilt University Medical Center, Nashville, TN
| | - Katie L Stone
- California Pacific Medical Center Research Institute, San Francisco, CA
| | | | - Brian B Koo
- Department of Neurology, Yale School of Medicine, New Haven, CT
| | - John W Winkelman
- Departments of Psychiatry and Neurology, Massachusetts General Hospital, Boston, MA
| | - Susan Redline
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.,Department of medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Murray A Mittleman
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Reena Mehra
- Sleep Center, Neurologic Institute, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH
| | | |
Collapse
|
10
|
Brain regions associated with periodic leg movements during sleep in restless legs syndrome. Sci Rep 2020; 10:1615. [PMID: 32005856 PMCID: PMC6994717 DOI: 10.1038/s41598-020-58365-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 01/07/2020] [Indexed: 11/24/2022] Open
Abstract
The neural substrates related to periodic leg movements during sleep (PLMS) remain uncertain, and the specific brain regions involved in PLMS have not been evaluated. We investigated the brain regions associated with PLMS and their severity using the electroencephalographic (EEG) source localization method. Polysomnographic data, including electromyographic, electrocardiographic, and 19-channel EEG signals, of 15 patients with restless legs syndrome were analyzed. We first identified the source locations of delta-band (2–4 Hz) spectral power prior to the onset of PLMS using a standardized low-resolution brain electromagnetic tomography method. Next, correlation analysis was conducted between current densities and PLMS index. Delta power initially and most prominently increased before leg movement (LM) onset in the PLMS series. Sources of delta power at −4~−3 seconds were located in the right pericentral, bilateral dorsolateral prefrontal, and cingulate regions. PLMS index was correlated with current densities at the right inferior parietal, temporoparietal junction, and middle frontal regions. In conclusion, our results suggest that the brain regions activated before periodic LM onset or associated with their severity are the large-scale motor network and provide insight into the cortical contribution of PLMS pathomechanism.
Collapse
|
11
|
Budhiraja R, Javaheri S, Pavlova MK, Epstein LJ, Omobomi O, Quan SF. Prevalence and correlates of periodic limb movements in OSA and the effect of CPAP therapy. Neurology 2019; 94:e1820-e1827. [PMID: 31882530 DOI: 10.1212/wnl.0000000000008844] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 11/11/2019] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE We sought to assess the prevalence, correlates, and consequences of periodic limb movements of sleep (PLMS) in persons with obstructive sleep apnea (OSA) and the effect (worsening or improvement) of continuous positive airway pressure (CPAP) therapy on PLMS in a large prospective multicenter randomized controlled trial. METHODS We performed retrospective analyses of data from the Apnea Positive Pressure Long-term Efficacy Study, a prospective multicenter randomized controlled trial. A total of 1,105 persons with OSA enrolled in this study underwent a polysomnographic investigation at baseline, another one for CPAP titration, and another study 6 months after randomization to either active CPAP or sham CPAP. RESULTS Of all participants, 19.7% had PLM index (PLMI) ≥10/hour, 14.8% had PLMI ≥15/hour, 12.1% had PLMI ≥20/hour, 9.3% had PLMI ≥25/hour, and 7.5% had PLMI ≥30/hour. The odds of having a PLMI ≥10 were higher in older participants (odds ratio [OR] 1.03, p < 0.001), men (OR 1.63. p = 0.007), those using antidepressants (OR 1.48. p = 0.048), and those with higher caffeine use (OR 1.01, p = 0.04). After controlling for OSA and depression, PLMS were associated with increased sleep latency, reduced sleep efficiency, and reduced total sleep time. No significant relationships were noted between PLMS frequency and subjective sleepiness (Epworth Sleepiness Scale score) or objective sleepiness (Maintenance of Wakefulness Test). There was no differential effect of CPAP in comparison to sham CPAP on PLMS after 6 months of therapy. CONCLUSIONS PLMS are common in patients with OSA and are associated with a significant reduction in sleep quality over and above that conferred by OSA. Treatment with CPAP does not affect the severity of PLMS.
Collapse
Affiliation(s)
- Rohit Budhiraja
- From the Divisions of Sleep and Circadian Disorders (R.B., S.J., L.J.E., O.O., S.F.Q.) and Pulmonary and Critical Care Medicine (R.B.), Department of Medicine, and Division of Sleep and Circadian Disorders (M.K.P.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Arizona Respiratory Center (S.F.Q.), University of Arizona, Tucson.
| | - Sogol Javaheri
- From the Divisions of Sleep and Circadian Disorders (R.B., S.J., L.J.E., O.O., S.F.Q.) and Pulmonary and Critical Care Medicine (R.B.), Department of Medicine, and Division of Sleep and Circadian Disorders (M.K.P.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Arizona Respiratory Center (S.F.Q.), University of Arizona, Tucson
| | - Milena K Pavlova
- From the Divisions of Sleep and Circadian Disorders (R.B., S.J., L.J.E., O.O., S.F.Q.) and Pulmonary and Critical Care Medicine (R.B.), Department of Medicine, and Division of Sleep and Circadian Disorders (M.K.P.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Arizona Respiratory Center (S.F.Q.), University of Arizona, Tucson
| | - Lawrence J Epstein
- From the Divisions of Sleep and Circadian Disorders (R.B., S.J., L.J.E., O.O., S.F.Q.) and Pulmonary and Critical Care Medicine (R.B.), Department of Medicine, and Division of Sleep and Circadian Disorders (M.K.P.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Arizona Respiratory Center (S.F.Q.), University of Arizona, Tucson
| | - Olabimpe Omobomi
- From the Divisions of Sleep and Circadian Disorders (R.B., S.J., L.J.E., O.O., S.F.Q.) and Pulmonary and Critical Care Medicine (R.B.), Department of Medicine, and Division of Sleep and Circadian Disorders (M.K.P.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Arizona Respiratory Center (S.F.Q.), University of Arizona, Tucson
| | - Stuart F Quan
- From the Divisions of Sleep and Circadian Disorders (R.B., S.J., L.J.E., O.O., S.F.Q.) and Pulmonary and Critical Care Medicine (R.B.), Department of Medicine, and Division of Sleep and Circadian Disorders (M.K.P.), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Arizona Respiratory Center (S.F.Q.), University of Arizona, Tucson
| |
Collapse
|
12
|
Ferré S, Ciruela F. Functional and Neuroprotective Role of Striatal Adenosine A 2A Receptor Heterotetramers. J Caffeine Adenosine Res 2019; 9:89-97. [PMID: 31559390 PMCID: PMC6761580 DOI: 10.1089/caff.2019.0008] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In the striatum, adenosine A2A receptors (A2AR) are mainly expressed within the soma and dendrites of the striatopallidal neuron. A predominant proportion of these striatal postsynaptic A2AR form part of the macromolecular complexes that include A2AR-dopamine D2 receptor (D2R) heteromers, Golf and Gi/o proteins, and the effector adenylyl cyclase (AC), subtype AC5. The A2AR-D2R heteromers have a tetrameric structure, constituted by A2AR and D2R homomers. By means of reciprocal antagonistic allosteric interactions and antagonistic interactions at the effector level between adenosine and dopamine, the A2AR-D2R heterotetramer-AC5 complex acts an integrative molecular device, which determines a switch between the adenosine-facilitated activation and the dopamine-facilitated inhibition of the striatopallidal neuron. Striatal adenosine also plays an important presynaptic modulatory role, driving the function of corticostriatal terminals. This control is mediated by adenosine A1 receptors (A1R) and A2AR, which establish intermolecular interactions forming A1R-A2AR heterotetramers. Here, we review the functional role of both presynaptic and postsynaptic striatal A2AR heterotetramers as well as their possible neuroprotective role. We hypothesize that alterations in the homomer/heteromer stoichiometry (i.e., increase or decrease in the proportion of A2AR forming homomers or heteromers) are pathogenetically involved in neurological disorders, specifically in Parkinson's disease and restless legs syndrome.
Collapse
Affiliation(s)
- Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, Maryland
| | - Francisco Ciruela
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, School of Medicine, IDIBELL, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.,Institute of Neurosciences, University of Barcelona, Barcelona, Spain
| |
Collapse
|
13
|
Affiliation(s)
- Sergi Ferré
- Editor in Chief of the Journal of Caffeine and Adenosine Research
- Integrative Neurobiology Section, National Institute on Drug Abuse, IRP, NIH, DHHS, Baltimore, Maryland
| |
Collapse
|
14
|
Rosales-Lagarde A, Rodriguez-Torres EE, Itzá-Ortiz BA, Miramontes P, Vázquez-Tagle G, Enciso-Alva JC, García-Muñoz V, Cubero-Rego L, Pineda-Sánchez JE, Martínez-Alcalá CI, Lopez-Noguerola JS. The Color of Noise and Weak Stationarity at the NREM to REM Sleep Transition in Mild Cognitive Impaired Subjects. Front Psychol 2018; 9:1205. [PMID: 30065684 PMCID: PMC6056768 DOI: 10.3389/fpsyg.2018.01205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 06/22/2018] [Indexed: 11/21/2022] Open
Abstract
In Older Adults (OAs), Electroencephalogram (EEG) slowing in frontal lobes and a diminished muscle atonia during Rapid Eye Movement sleep (REM) have each been effective tracers of Mild Cognitive Impairment (MCI), but this relationship remains to be explored by non-linear analysis. Likewise, data provided by EEG, EMG (Electromyogram) and EOG (Electrooculogram)—the three required sleep indicators—during the transition from REM to Non-REM (NREM) sleep have not been related jointly to MCI. Therefore, the main aim of the study was to explore, with results for Detrended Fluctuation Analysis (DFA) and multichannel DFA (mDFA), the Color of Noise (CN) at the NREM to REM transition in OAs with MCI vs. subjects with good performances. The comparisons for the transition from NREM to REM were made for each group at each cerebral area, taking bilateral derivations to evaluate interhemispheric coupling and anteroposterior and posterior networks. In addition, stationarity analysis was carried out to explore if the three markers distinguished between the groups. Neuropsi and the Mini-Mental State Examination (MMSE) were administered, as well as other geriatric tests. One night polysomnography was applied to 6 OAs with MCI (68.1 ± 3) and to 7 subjects without it (CTRL) (64.5 ± 9), and pre-REM and REM epochs were analyzed for each subject. Lower scores for attention, memory and executive funcions and a greater index of arousals during sleep were found for the MCI group. Results confirmed that EOGs constituted significant markers of MCI, increasing the CN for the MCI group in REM sleep. The CN of the EEG from the pre-REM to REM was higher for the MCI group vs. the opposite for the CTRL group at frontotemporal areas. Frontopolar interhemispheric scaling values also followed this trend as well as right anteroposterior networks. EMG Hurst values for both groups were lower than those for EEG and EOG. Stationarity analyses showed differences between stages in frontal areas and right and left EOGs for both groups. These results may demonstrate the breakdown of fractality of areas especially involved in executive functioning and the way weak stationarity analyses may help to distinguish between sleep stages in OAs.
Collapse
Affiliation(s)
- Alejandra Rosales-Lagarde
- Consejo Nacional de Ciencia y Tecnología, Mexico City, Mexico.,Área Académica de Gerontología, San Agustín Tlaxiaca, Mexico
| | | | | | - Pedro Miramontes
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | | | | | | | | | - José E Pineda-Sánchez
- Área Académica de Psicología, Universidad Autónoma del Estado de Hidalgo, San Agustín Tlaxiaca, Mexico
| | - Claudia I Martínez-Alcalá
- Consejo Nacional de Ciencia y Tecnología, Mexico City, Mexico.,Área Académica de Gerontología, San Agustín Tlaxiaca, Mexico
| | - Jose S Lopez-Noguerola
- Área Académica de Gerontología, San Agustín Tlaxiaca, Mexico.,Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University of Medicine, Goettingen, Germany
| |
Collapse
|
15
|
Congiu P, Puligheddu M, Figorilli M, Ferri R. Periodic Leg Movements During Sleep and Cardiovascular and/or Cerebrovascular Morbidity. CURRENT SLEEP MEDICINE REPORTS 2018. [DOI: 10.1007/s40675-018-0101-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
16
|
Ferré S, Quiroz C, Guitart X, Rea W, Seyedian A, Moreno E, Casadó-Anguera V, Díaz-Ríos M, Casadó V, Clemens S, Allen RP, Earley CJ, García-Borreguero D. Pivotal Role of Adenosine Neurotransmission in Restless Legs Syndrome. Front Neurosci 2018; 11:722. [PMID: 29358902 PMCID: PMC5766678 DOI: 10.3389/fnins.2017.00722] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 12/11/2017] [Indexed: 11/13/2022] Open
Abstract
The symptomatology of Restless Legs Syndrome (RLS) includes periodic leg movements during sleep (PLMS), dysesthesias, and hyperarousal. Alterations in the dopaminergic system, a presynaptic hyperdopaminergic state, seem to be involved in PLMS, while alterations in glutamatergic neurotransmission, a presynaptic hyperglutamatergic state, seem to be involved in hyperarousal and also PLMS. Brain iron deficiency (BID) is well-recognized as a main initial pathophysiological mechanism of RLS. BID in rodents have provided a pathogenetic model of RLS that recapitulates the biochemical alterations of the dopaminergic system of RLS, although without PLMS-like motor abnormalities. On the other hand, BID in rodents reproduces the circadian sleep architecture of RLS, indicating the model could provide clues for the hyperglutamatergic state in RLS. We recently showed that BID in rodents is associated with changes in adenosinergic transmission, with downregulation of adenosine A1 receptors (A1R) as the most sensitive biochemical finding. It was hypothesized that A1R downregulation leads to hypersensitive striatal glutamatergic terminals and facilitation of striatal dopamine release. Hypersensitivity of striatal glutamatergic terminals was demonstrated by an optogenetic-microdialysis approach in the rodent with BID, indicating that it could represent a main pathogenetic factor that leads to PLMS in RLS. In fact, the dopaminergic agonists pramipexole and ropinirole and the α2δ ligand gabapentin, used in the initial symptomatic treatment of RLS, completely counteracted optogenetically-induced glutamate release from both normal and BID-induced hypersensitive corticostriatal glutamatergic terminals. It is a main tenet of this essay that, in RLS, a single alteration in the adenosinergic system, downregulation of A1R, disrupts the adenosine-dopamine-glutamate balance uniquely controlled by adenosine and dopamine receptor heteromers in the striatum and also the A1R-mediated inhibitory control of glutamatergic neurotransmission in the cortex and other non-striatal brain areas, which altogether determine both PLMS and hyperarousal. Since A1R agonists would be associated with severe cardiovascular effects, it was hypothesized that inhibitors of nucleoside equilibrative transporters, such as dipyridamole, by increasing the tonic A1R activation mediated by endogenous adenosine, could represent a new alternative therapeutic strategy for RLS. In fact, preliminary clinical data indicate that dipyridamole can significantly improve the symptomatology of RLS.
Collapse
Affiliation(s)
- Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - César Quiroz
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - Xavier Guitart
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - William Rea
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - Arta Seyedian
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - Estefanía Moreno
- Center for Biomedical Research in Neurodegenerative Diseases Network and Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Institute of Biomedicine of the University of Barcelona, University of Barcelona, Barcelona, Spain
| | - Verònica Casadó-Anguera
- Center for Biomedical Research in Neurodegenerative Diseases Network and Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Institute of Biomedicine of the University of Barcelona, University of Barcelona, Barcelona, Spain
| | - Manuel Díaz-Ríos
- Department of Anatomy and Neurobiology and Institute of Neurobiology, University of Puerto Rico, San Juan, PR, United States
| | - Vicent Casadó
- Center for Biomedical Research in Neurodegenerative Diseases Network and Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Institute of Biomedicine of the University of Barcelona, University of Barcelona, Barcelona, Spain
| | - Stefan Clemens
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, United States
| | - Richard P Allen
- Center for Restless Legs Study, Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
| | - Christopher J Earley
- Center for Restless Legs Study, Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
| | | |
Collapse
|
17
|
Yepes G, Guitart X, Rea W, Newman AH, Allen RP, Earley CJ, Quiroz C, Ferré S. Targeting hypersensitive corticostriatal terminals in restless legs syndrome. Ann Neurol 2017; 82:951-960. [PMID: 29171915 DOI: 10.1002/ana.25104] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 11/16/2017] [Accepted: 11/16/2017] [Indexed: 12/22/2022]
Abstract
OBJECTIVE The first aim was to demonstrate a previously hypothesized increased sensitivity of corticostriatal glutamatergic terminals in the rodent with brain iron deficiency (BID), a pathogenetic model of restless legs syndrome (RLS). The second aim was to determine whether these putative hypersensitive terminals could constitute a significant target for drugs effective in RLS, including dopamine agonists (pramipexole and ropinirole) and α2 δ ligands (gabapentin). METHODS A recently introduced in vivo optogenetic-microdialysis approach was used, which allows the measurement of the extracellular concentration of glutamate upon local light-induced stimulation of corticostriatal glutamatergic terminals. The method also allows analysis of the effect of local perfusion of compounds within the same area being sampled for glutamate. RESULTS BID rats showed hypersensitivity of corticostriatal glutamatergic terminals (lower frequency of optogenetic stimulation to induce glutamate release). Both hypersensitive and control glutamatergic terminals were significant targets for locally perfused pramipexole, ropinirole, and gabapentin, which significantly counteracted optogenetically induced glutamate release. The use of selective antagonists demonstrated the involvement of dopamine D4 and D2 receptor subtypes in the effects of pramipexole. INTERPRETATION Hypersensitivity of corticostriatal glutamatergic terminals can constitute a main pathogenetic mechanism of RLS symptoms. Selective D4 receptor agonists, by specifically targeting these terminals, should provide a new efficient treatment with fewer secondary effects. Ann Neurol 2017;82:951-960.
Collapse
Affiliation(s)
- Gabriel Yepes
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - Xavier Guitart
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - William Rea
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - Amy H Newman
- Medicinal Chemistry Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - Richard P Allen
- Center for Restless Legs Study, Department of Neurology, Johns Hopkins University, Baltimore, MD
| | - Christopher J Earley
- Center for Restless Legs Study, Department of Neurology, Johns Hopkins University, Baltimore, MD
| | - César Quiroz
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD
| | - Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD
| |
Collapse
|
18
|
Chiaro G, Maestri M, Riccardi S, Haba-Rubio J, Miano S, Bassetti CL, Heinzer RC, Manconi M. Sleep-Related Rhythmic Movement Disorder and Obstructive Sleep Apnea in Five Adult Patients. J Clin Sleep Med 2017; 13:1213-1217. [PMID: 28859719 DOI: 10.5664/jcsm.6778] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/06/2017] [Indexed: 01/06/2023]
Abstract
ABSTRACT Sleep-related rhythmic movements (SRRMs) are typical in infancy and childhood, where they usually occur at the wake-to-sleep transition. However, they have rarely been observed in adults, where they can be idiopathic or associated with other sleep disorders including sleep apnea. We report a case series of 5 adults with sleep-related rhythmic movement disorder, 4 of whom had a previous history of SRRMs in childhood. SRRMs mostly occurred in consolidated sleep, in association with pathological respiratory events, predominantly longer ones, especially during stage R sleep, and recovered in 1 patient with continuous positive airway pressure therapy. We hypothesize that sleep apneas may act as a trigger of rhythmic motor events through a respiratory-related arousal mechanism in genetically predisposed subjects.
Collapse
Affiliation(s)
- Giacomo Chiaro
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital of Lugano, Lugano, Switzerland
| | - Michelangelo Maestri
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital of Lugano, Lugano, Switzerland
| | - Silvia Riccardi
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital of Lugano, Lugano, Switzerland
| | - José Haba-Rubio
- Center for Investigation and Research in Sleep (CIRS), University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Silvia Miano
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital of Lugano, Lugano, Switzerland
| | | | - Raphaël C Heinzer
- Center for Investigation and Research in Sleep (CIRS), University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Mauro Manconi
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital of Lugano, Lugano, Switzerland.,University Department of Neurology, Inselspital, Bern, Switzerland
| |
Collapse
|
19
|
Abstract
Sleep plays a vital role in brain function and systemic physiology across many body systems. Problems with sleep are widely prevalent and include deficits in quantity and quality of sleep; sleep problems that impact the continuity of sleep are collectively referred to as sleep disruptions. Numerous factors contribute to sleep disruption, ranging from lifestyle and environmental factors to sleep disorders and other medical conditions. Sleep disruptions have substantial adverse short- and long-term health consequences. A literature search was conducted to provide a nonsystematic review of these health consequences (this review was designed to be nonsystematic to better focus on the topics of interest due to the myriad parameters affected by sleep). Sleep disruption is associated with increased activity of the sympathetic nervous system and hypothalamic-pituitary-adrenal axis, metabolic effects, changes in circadian rhythms, and proinflammatory responses. In otherwise healthy adults, short-term consequences of sleep disruption include increased stress responsivity, somatic pain, reduced quality of life, emotional distress and mood disorders, and cognitive, memory, and performance deficits. For adolescents, psychosocial health, school performance, and risk-taking behaviors are impacted by sleep disruption. Behavioral problems and cognitive functioning are associated with sleep disruption in children. Long-term consequences of sleep disruption in otherwise healthy individuals include hypertension, dyslipidemia, cardiovascular disease, weight-related issues, metabolic syndrome, type 2 diabetes mellitus, and colorectal cancer. All-cause mortality is also increased in men with sleep disturbances. For those with underlying medical conditions, sleep disruption may diminish the health-related quality of life of children and adolescents and may worsen the severity of common gastrointestinal disorders. As a result of the potential consequences of sleep disruption, health care professionals should be cognizant of how managing underlying medical conditions may help to optimize sleep continuity and consider prescribing interventions that minimize sleep disruption.
Collapse
Affiliation(s)
- Goran Medic
- Market Access, Horizon Pharma B.V., Utrecht
- Unit of Pharmacoepidemiology & Pharmacoeconomics, Department of Pharmacy, University of Groningen, Groningen, The Netherlands
| | | | | |
Collapse
|
20
|
Quiroz C, Gulyani S, Ruiqian W, Bonaventura J, Cutler R, Pearson V, Allen RP, Earley CJ, Mattson MP, Ferré S. Adenosine receptors as markers of brain iron deficiency: Implications for Restless Legs Syndrome. Neuropharmacology 2016; 111:160-168. [PMID: 27600688 DOI: 10.1016/j.neuropharm.2016.09.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/20/2016] [Accepted: 09/02/2016] [Indexed: 01/01/2023]
Abstract
Deficits of sensorimotor integration with periodic limb movements during sleep (PLMS) and hyperarousal and sleep disturbances in Restless Legs Syndrome (RLS) constitute two pathophysiologically distinct but interrelated clinical phenomena, which seem to depend mostly on alterations in dopaminergic and glutamatergic neurotransmission, respectively. Brain iron deficiency is considered as a main pathogenetic mechanism in RLS. Rodents with brain iron deficiency represent a valuable pathophysiological model of RLS, although they do not display motor disturbances. Nevertheless, they develop the main neurochemical dopaminergic changes found in RLS, such as decrease in striatal dopamine D2 receptor density. On the other hand, brain iron deficient mice exhibit the characteristic pattern of hyperarousal in RLS, providing a tool to find the link between brain iron deficiency and sleep disturbances in RLS. The present study provides evidence for a role of the endogenous sleep-promoting factor adenosine. Three different experimental preparations, long-term (22 weeks) severe or moderate iron-deficient (ID) diets (3- or 7-ppm iron diet) in mice and short-term (3 weeks) severe ID diet (3-ppm iron diet) in rats, demonstrated a significant downregulation (Western blotting in mouse and radioligand binding saturation experiments in rat brain tissue) of adenosine A1 receptors (A1R) in the cortex and striatum, concomitant to striatal D2R downregulation. On the other hand, the previously reported upregulation of adenosine A2A receptors (A2AR) was only observed with severe ID in both mice and rats. The results suggest a key role for A1R downregulation in the PLMS and hyperarousal in RLS.
Collapse
Affiliation(s)
- César Quiroz
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Seema Gulyani
- Laboratory of Neurosciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Wan Ruiqian
- Laboratory of Neurosciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Jordi Bonaventura
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Roy Cutler
- Laboratory of Neurosciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Virginia Pearson
- Center for Restless Legs Study, Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA
| | - Richard P Allen
- Center for Restless Legs Study, Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA
| | - Christopher J Earley
- Center for Restless Legs Study, Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21224, USA
| | - Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Sergi Ferré
- Integrative Neurobiology Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA.
| |
Collapse
|
21
|
Zhang Z, Schneider M, Laures M, Qi M, Khatami R. The Comparisons of Cerebral Hemodynamics Induced by Obstructive Sleep Apnea with Arousal and Periodic Limb Movement with Arousal: A Pilot NIRS Study. Front Neurosci 2016; 10:403. [PMID: 27630539 PMCID: PMC5005379 DOI: 10.3389/fnins.2016.00403] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/18/2016] [Indexed: 11/13/2022] Open
Abstract
Obstructive sleep apnea syndrome (OSA) and restless legs syndrome (RLS) with periodic limb movement during sleep (PLMS) are two sleep disorders characterized by repetitive respiratory or movement events associated with cortical arousals. We compared the cerebral hemodynamic changes linked to periodic apneas/hypopneas with arousals (AHA) in four OSA-patients with periodic limb movements (PLMA) with arousals in four patients with RLS-PLMS using near-infrared spectroscopy (NIRS). AHA induced homogenous pattern of periodic fluctuations in oxygenated (HbO2) and deoxygenated (HHb) hemoglobin, i.e., the decrease of HbO2 was accompanied by an increase of HHb during the respiratory event and resolved to reverse pattern when cortical arousal started. Blood volume (BV) showed the same pattern as HHb but with relative smaller amplitude in most of the AHA events.These changing patterns were significant as Wilcoxon signed-rank tests gave p < 0.001 when comparing the area under the curve of these hemodynamic parameters to zero. By contrast, in PLMA limb movements induced periodic increments in HbO2 and BV (Wilcoxon signed-rank tests, p < 0.001), but HHb changed more heterogeneously even during the events coming from the same patient. Heart rate (HR) also showed different patterns between AHA and PLMA. It significantly decreased during the respiratory event (Wilcoxon signed-rank test, p < 0.001) and then increased after the occurrence of cortical arousal (Wilcoxon signed-rank test, p < 0.001); while in PLMA HR first increased preceding the occurrence of cortical arousal (Wilcoxon signed-rank test, p < 0.001) and then decreased. The results of this preliminary study show that both AHA and PLMA induce changes in cerebral hemodynamics. The occurrence of cortical arousal is accompanied by increased HR in both events, but by different BV changes (i.e., decreased/increased BV in AHA/PLMA, respectively). HR changes may partially account for the increased cerebral hemodynamics during PLMA; whereas in AHA probable vasodilatation mediated by hypoxia/hypercapnia is more crucial for the post-arousal hemodynamics. The differences between changes of cerebral hemodynamics and HR may indicate different pathological mechanisms behind these two sleep disorder events.
Collapse
Affiliation(s)
- Zhongxing Zhang
- Center for Sleep Medicine and Sleep Research, Clinic BarmelweidBarmelweid, Switzerland
- Bern Network for Epilepsy, Sleep and Consciousness (BENESCO), Department of Neurology, University Hospital Bern, University of BernBern, Switzerland
| | - Maja Schneider
- Center for Sleep Medicine and Sleep Research, Clinic BarmelweidBarmelweid, Switzerland
| | - Marco Laures
- Center for Sleep Medicine and Sleep Research, Clinic BarmelweidBarmelweid, Switzerland
| | - Ming Qi
- Center for Sleep Medicine and Sleep Research, Clinic BarmelweidBarmelweid, Switzerland
| | - Ramin Khatami
- Center for Sleep Medicine and Sleep Research, Clinic BarmelweidBarmelweid, Switzerland
- Bern Network for Epilepsy, Sleep and Consciousness (BENESCO), Department of Neurology, University Hospital Bern, University of BernBern, Switzerland
| |
Collapse
|
22
|
Koo BB, Bagai K, Walters AS. Restless Legs Syndrome: Current Concepts about Disease Pathophysiology. TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2016; 6:401. [PMID: 27536462 PMCID: PMC4961894 DOI: 10.7916/d83j3d2g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 06/07/2016] [Indexed: 01/31/2023]
Abstract
Background In the past few decades, much has been learned about the pathophysiology of restless legs syndrome (RLS). Investigators have studied neuropathology, imaging, electrophysiology, and genetics of RLS, identifying brain regions and biological systems affected in RLS. This manuscript will review RLS pathophysiology literature, examining the RLS state through consideration of the neuroanatomy, then the biological, organ, and genetic systems. Methods Pubmed (1966 to April 2016) was searched for the term “restless legs syndrome” cross-referenced with “pathophysiology,” “pathogenesis,” “pathology,” or “imaging.” English language papers were reviewed. Studies that focused on RLS in relation to another disease were not reviewed. Results Although there are no gross structural brain abnormalities in RLS, widespread brain areas are activated, including the pre- and post-central gyri, cingulate cortex, thalamus, and cerebellum. Pathologically, the most consistent finding is striatal iron deficiency in RLS patients. A host of other biological systems are also altered in RLS, including the dopaminergic, oxygen-sensing, opioid, glutamatergic, and serotonergic systems. Polymorphisms in genes including BTBD9 and MEIS1 are associated with RLS. Discussion RLS is a neurologic sensorimotor disorder that involves pathology, most notably iron deficiency, in motor and sensory brain areas. Brain areas not subserving movement or sensation such as the cingulate cortex and cerebellum are also involved. Other biological systems including the dopaminergic, oxygen-sensing, opioid, glutamatergic, and serotonergic systems are involved. Further research is needed to determine which of these anatomic locations or biological systems are affected primarily, and which are affected in a secondary response.
Collapse
Affiliation(s)
- Brian B Koo
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA; Department of Neurology, Connecticut Veterans Affairs Health System, West Haven, CT, USA; Yale Center for Neuroepidemiology & Clinical Neurological Research, New Haven, CT, USA
| | - Kanika Bagai
- Department of Neurology, Vanderbilt University, Nashville, TN, USA
| | - Arthur S Walters
- Department of Neurology, Vanderbilt University, Nashville, TN, USA
| |
Collapse
|
23
|
Ferri R, Manconi M, Rundo F, Zucconi M, Aricò D, Bruni O, Ferini-Strambi L, Fulda S. A Data-Driven Analysis of the Rules Defining Bilateral Leg Movements during Sleep. Sleep 2016; 39:413-21. [PMID: 26414897 PMCID: PMC4712394 DOI: 10.5665/sleep.5454] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 08/28/2015] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES The aim of this study was to describe and analyze the association between bilateral leg movements (LMs) during sleep in subjects with restless legs syndrome (RLS), in order to eventually support or challenge the current scoring rules defining bilateral LMs. METHODS Polysomnographic recordings of 100 untreated patients with RLS (57 women and 43 males, mean age 57 y) were included. In each recording, we selected as reference all LMs that occurred during sleep and that were separated from another ipsilateral LM by at least 10 sec of EMG inactivity. For each reference LM and an evaluation interval from 5 sec before the onset to 5 sec after the offset of the reference LM, we evaluated (1) the presence or absence of contralateral leg movement activity and (2) the distribution of the onset-to-onset and (3) the offset-to-onset differences between bilateral LMs. RESULTS We selected a mean of 368 (± 222 standard deviation [SD]) reference LMs per subject. For 42% (± 22%) of the reference LMs no contralateral leg movement activity was observed within the evaluation interval. In 55% (± 22%) exactly one and in 3% (± 2%) more than one contralateral LM was observed. A further evaluation of events where exactly one contralateral LM was observed showed that in most (1) the two LMs were overlapping (93% ± 9% SD) and (2) were classified as bilateral according to the World Association of Sleep Medicine and the International Restless Legs Syndrome Study Group (WASM/ IRLSSG) (96% ± 6% SD) and (3) the American Academy of Sleep Medicine scoring rules (99% ± 2% SD). Although there was a systematic and statistically significant difference in standard LM indices during sleep based on the two different definitions of bilateral LMs, the size of the difference was not clinically meaningful (maximum individual, absolute difference in LM indices ± 2.5). In addition, we found that the duration of LMs within bilateral LM pairs was longer compared to monolateral LMs and that the duration of the single LMs in bilateral LM pairs tended to correlate. CONCLUSIONS The results of this study indicate that the two current standard scoring rules for the definition of bilateral LMs during sleep provide largely corresponding classifications in subjects with RLS and, in a clinical context, can be considered to be equivalent.
Collapse
Affiliation(s)
- Raffaele Ferri
- Sleep Research Centre, Department of Neurology IC, Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy
| | - Mauro Manconi
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital (EOC) of Lugano, Lugano, Switzerland
| | - Francesco Rundo
- Sleep Research Centre, Department of Neurology IC, Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy
| | - Marco Zucconi
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital (EOC) of Lugano, Lugano, Switzerland
| | - Debora Aricò
- Sleep Research Centre, Department of Neurology IC, Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy
| | - Oliviero Bruni
- Department of Social and Developmental Psychology, Sapienza University, Rome, Italy
| | - Luigi Ferini-Strambi
- Sleep Disorders Center, Department of Neurology, Scientific Institute and University Ospedale San Raffaele, Vita-Salute University, Milan, Italy
| | - Stephany Fulda
- Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital (EOC) of Lugano, Lugano, Switzerland
| |
Collapse
|
24
|
Sleep and Quality of Life Under Prolonged Release Oxycodone/Naloxone for Severe Restless Legs Syndrome: An Analysis of Secondary Efficacy Variables of a Double-Blind, Randomized, Placebo-Controlled Study with an Open-Label Extension. CNS Drugs 2016; 30:749-60. [PMID: 27401882 PMCID: PMC4982896 DOI: 10.1007/s40263-016-0372-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE The aim was to assess the effects of prolonged release oxycodone/naloxone (OXN PR) on sleep and quality of life (QoL) in patients with severe restless legs syndrome (RLS) refractory to first-line dopaminergic RLS treatment. METHODS Sleep and QoL data from a 12-week, randomized, double-blind, placebo-controlled study with subsequent 40-week, open-label extension were analyzed. Instruments included the Medical Outcomes Study (MOS) sleep scale, RLS-6 rating scale, and RLS-QoL questionnaire. RESULTS The full analysis population included 132 OXN PR and 144 placebo patients. After 12 treatment weeks, improvements in the MOS domains 'sleep disturbance' [-18.6; 95 % confidence interval (CI) -24.4 to -12.9; p < 0.0001], 'sleep adequacy' (14.9; 95 % CI 7.9-21.9; p < 0.0001), and 'sleep quantity' (0.77 h; 95 % CI 0.43-1.11; p < 0.0001) were significantly greater under OXN PR than under placebo. OXN PR also reduced symptom severity (when falling asleep and during the night) and daytime tiredness, and increased sleep satisfaction to a significantly greater extent than placebo (all p < 0.001; RLS-6). QoL improved in both treatment arms, with a significant difference of -9.02 (95 % CI -12.85 to -5.19; p < 0.001) in the mean sum score in favor of OXN PR. All sleep and QoL aspects also improved under 40 weeks of open-label OXN PR treatment. CONCLUSIONS OXN PR improved RLS symptom severity and sleep quantity and adequacy, resulting in greater sleep satisfaction, less daytime tiredness, and improved QoL. In appropriate patients, OXN PR should be considered as an alternative treatment option for severe RLS that cannot be controlled by first-line dopaminergic medications. TRIAL REGISTRATION ClinicalTrials.gov (NCT01112644) and EudraCT (2009-011107-23).
Collapse
|
25
|
Koo BB. Restless Legs Syndrome: Would You Like That with Movements or Without? Tremor Other Hyperkinet Mov (N Y) 2015; 5:316. [PMID: 26175956 PMCID: PMC4499805 DOI: 10.7916/d80p0z0h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 04/30/2015] [Indexed: 04/24/2023] Open
Abstract
The restless legs syndrome (RLS) is a common sensorimotor condition that often results in discomfort and sleep disturbance. Diagnosis of RLS is entirely clinical and based upon a patient's description of subjective symptoms, and thus when considering RLS diagnosis non-specificity is a real problem. RLS is associated with periodic limb movements during sleep (PLMS) in up to 90% of RLS sufferers; however, their presence is neither sufficient nor necessary for the diagnosis of RLS. The disease RLS and the motor phenomenon of PLMS share similarities in various areas, which include pathophysiology, pharmacology, genetics, and epidemiology. The purpose of this opinion piece is to outline the many similarities between RLS and PLMS in order to make an argument for the inclusion of PLMS as a supplementary diagnostic criterion of RLS, termed electro-clinical RLS, which would consist of the current clinical RLS diagnosis plus PLMS. This additional criterion could be used in cases where diagnosis is unclear to increase specificity or in research projects where proper diagnosis is desired at the investigational level.
Collapse
Affiliation(s)
- Brian B. Koo
- Department of Neurology, VA Connecticut Healthcare System, West Haven, Connecticut, USA
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|