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Larsson G, Julu POO, Witt Engerström I, Sandlund M, Lindström B. Walking on treadmill with Rett syndrome-Effects on the autonomic nervous system. Res Dev Disabil 2018; 83:99-107. [PMID: 30193160 DOI: 10.1016/j.ridd.2018.08.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 08/01/2018] [Accepted: 08/20/2018] [Indexed: 06/08/2023]
Abstract
People with Rett syndrome have deficient central autonomic control, which may interfere with walking. We have limited knowledge regarding the effects of exertion during physical activity in Rett syndrome. The aim was to investigate the autonomic responses during walking on a treadmill in Rett syndrome. Twenty-six females, 12 with Rett syndrome and 14 healthy females were included. All individuals started on the treadmill by standing still, followed by walking slowly with progressive speed until reaching maximum individual speed, which they kept for 6 min. Heart rate (HR), systolic (SBP), diastolic (DBP), mean arterial blood pressures (MAP), cardiac vagal tone (CVT), cardiac sensitivity to baroreflex (CSB), transcutaneous partial pressures of oxygen (pO2), carbon dioxide (pCO2), and breathing movements were recorded simultaneously and continuously. Autonomic responses were assessed by MAP, CSB and CVT during walking at 3 and 6 min. The changes in CSB and CVT in people with Rett syndrome compared to controls indicated more arousal, but only when the treadmill was started; as they continued walking, the arousal dropped to control level. People with Rett syndrome exhibited little changes in pCO2 whereas the controls showed increased values during walking. This suggests poor aerobic respiration in people with Rett syndrome during walking. Five people with Rett syndrome had Valsalva type of breathing at rest, three of those had normal breathing while walking on the treadmill while the remaining two started but soon stopped the Valsalva breathing during the walk. Our results show that individuals with Rett syndrome can walk for up to 6 min at their own maximum sustainable speed on a treadmill. Energy production may be low during walking in Rett syndrome, which could cause early tiredness. A treadmill can be used in people with Rett syndrome, but must be introduced slowly and should be individually tailored. We propose that walking promotes regular breathing in Rett syndrome.
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Affiliation(s)
- Gunilla Larsson
- Department of Community Medicine and Rehabilitation, Umeå University, S-90187 Umeå, Sweden; Swedish National Rett Center, PO Box 601, SE-83223 Frösön, Sweden(1).
| | - Peter O O Julu
- Swedish National Rett Center, PO Box 601, SE-83223 Frösön, Sweden(1); Breakspear Medical, Hertfordshire, United Kingdom.
| | | | - Marlene Sandlund
- Department of Community Medicine and Rehabilitation, Umeå University, S-90187 Umeå, Sweden.
| | - Britta Lindström
- Department of Community Medicine and Rehabilitation, Umeå University, S-90187 Umeå, Sweden.
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2
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Saxena M, Shour T, Shah M, Wolff CB, Julu POO, Kapil V, Collier DJ, Ng FL, Gupta A, Balawon A, Pheby J, Zak A, Rull G, O'Brien B, Schmieder RE, Lobo MD. Attenuation of Splanchnic Autotransfusion Following Noninvasive Ultrasound Renal Denervation: A Novel Marker of Procedural Success. J Am Heart Assoc 2018; 7:JAHA.118.009151. [PMID: 29895590 PMCID: PMC6220552 DOI: 10.1161/jaha.118.009151] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Renal denervation has no validated marker of procedural success. We hypothesized that successful renal denervation would reduce renal sympathetic nerve signaling demonstrated by attenuation of α-1-adrenoceptor-mediated autotransfusion during the Valsalva maneuver. METHODS AND RESULTS In this substudy of the Wave IV Study: Phase II Randomized Sham Controlled Study of Renal Denervation for Subjects With Uncontrolled Hypertension, we enrolled 23 subjects with resistant hypertension. They were randomized either to bilateral renal denervation using therapeutic levels of ultrasound energy (n=12) or sham application of diagnostic ultrasound (n=11). Within-group changes in autonomic parameters, office and ambulatory blood pressure were compared between baseline and 6 months in a double-blind manner. There was significant office blood pressure reduction in both treatment (16.1±27.3 mm Hg, P<0.05) and sham groups (27.9±15.0 mm Hg, P<0.01) because of which the study was discontinued prematurely. However, during the late phase II (Iii) of Valsalva maneuver, renal denervation resulted in substantial and significant reduction in mean arterial pressure (21.8±25.2 mm Hg, P<0.05) with no significant changes in the sham group. Moreover, there were significant reductions in heart rate in the actively treated group at rest (6.0±11.5 beats per minute, P<0.05) and during postural changes (supine 7.2±8.4 beats per minute, P<0.05, sit up 12.7±16.7 beats per minute, P<0.05), which were not observed in the sham group. CONCLUSIONS Blood pressure reduction per se is not necessarily a marker of successful renal nerve ablation. Reduction in splanchnic autotransfusion following renal denervation has not been previously demonstrated and denotes attenuation of (renal) sympathetic efferent activity and could serve as a marker of procedural success. CLINICAL TRIAL REGISTRATION URL: https://www.clinicaltrials.gov. Unique identifier: NCT02029885.
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Affiliation(s)
- Manish Saxena
- Barts BP Centre of Excellence, Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom .,William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Tariq Shour
- Barts BP Centre of Excellence, Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom.,William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Mussadiq Shah
- William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Christopher B Wolff
- William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Peter O O Julu
- William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Vikas Kapil
- Barts BP Centre of Excellence, Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom.,William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - David J Collier
- William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Fu Liang Ng
- Barts BP Centre of Excellence, Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom.,William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Ajay Gupta
- Barts BP Centre of Excellence, Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom.,William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Armida Balawon
- William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Jane Pheby
- William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Anne Zak
- William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Gurvinder Rull
- Barts BP Centre of Excellence, Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom
| | - Benjamin O'Brien
- William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
| | - Roland E Schmieder
- Department of Nephrology and Hypertension, University Hospital, University of Erlangen/Nuremberg, Erlangen, Germany
| | - Melvin D Lobo
- Barts BP Centre of Excellence, Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom.,William Harvey Research Institute, Centre for Clinical Pharmacology, Barts NIHR Cardiovascular Biomedical Research Unit, Queen Mary University London, London, United Kingdom
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3
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Julu POO, Shah M, Monro JA, Puri BK. Carbon dioxide therapy in hypocapnic respiratory failure. Med Hypotheses 2018; 110:101-104. [PMID: 29317050 DOI: 10.1016/j.mehy.2017.11.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 11/30/2017] [Indexed: 10/18/2022]
Abstract
Oxygen therapy, usually administered by a facemask or nasal cannulae, is the current default treatment of respiratory failure. Since respiration entails intake of oxygen and release of carbon dioxide from tissues as waste product, the notion of administering carbon dioxide in respiratory failure appears counter-intuitive. However, carbon dioxide stimulates the chemosensitive area of the medulla, known as the central respiratory chemoreceptor, which activates the respiratory groups of neurones in the brainstem and stimulates inspiration thereby initiating oxygen intake during normal breathing. This vital initiation of normal breathing is via a reduction in the pH of the cerebrospinal fluid and the medullary interstitial fluid. We hypothesise that in cases of type I respiratory failure in which the PaCO2 is low, administration of carbon dioxide by inhalation would stimulate the respiratory groups of brainstem neurones and facilitate breathing, which would be of therapeutic value. Preliminary clinical evidence in favour of this hypothesis is presented and we recommend that a formal randomised study be carried out.
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Affiliation(s)
- P O O Julu
- Breakspear Medical Group, Hemel Hempstead, Hertfordshire, UK; Queen Mary University of London and the William Harvey Research Institute, Barts and the London School of Medicine, UK
| | - M Shah
- Breakspear Medical Group, Hemel Hempstead, Hertfordshire, UK; Queen Mary University of London and the William Harvey Research Institute, Barts and the London School of Medicine, UK
| | - J A Monro
- Breakspear Medical Group, Hemel Hempstead, Hertfordshire, UK
| | - B K Puri
- Department of Medicine, Imperial College London, UK.
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4
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Puri BK, Monro JA, Julu POO, Kingston MC, Shah M. Hyperosmia in Lyme disease. Arq Neuro-Psiquiatr 2014; 72:596-7. [DOI: 10.1590/0004-282x20140109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 06/05/2014] [Indexed: 11/21/2022]
Abstract
Neurological involvement in Lyme disease has been reported to include meningitis, cranial neuropathy and radiculoneuritis. While it is known that in some cases of asceptic meningitis patients may develop hyperosmia, the association between hyperosmia and Lyme disease has not previously been studied. Objective To carry out the first systematic study to ascertain whether hyperosmia is also a feature of Lyme disease. Method A questionnaire regarding abnormal sensory sensitivity in respect of the sense of smell was administered to 16 serologically positive Lyme disease patients and to 18 control subjects. Results The two groups were matched in respect of age, sex and body mass. None of the 34 subjects was suffering from migraine. Eight (50%) of the Lyme patients and none (0%) of the controls suffered from hyperosmia (p=0.0007). Conclusion This first systematic controlled study showed that Lyme disease is associated with hyperosmia.
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Affiliation(s)
| | | | - Peter O. O. Julu
- Imperial College London, UK; Hemel Hempstead, UK; Queen Mary University of London, UK; The William Harvey Research Institute, UK; London School of Medicine, UK; National Rett Center, Sweden
| | | | - Mussadiq Shah
- Hemel Hempstead, UK; Queen Mary University of London, UK; The William Harvey Research Institute, UK; London School of Medicine, UK
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5
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Larsson G, Julu POO, Witt Engerström I, Sandlund M, Lindström B. Normal reactions to orthostatic stress in Rett syndrome. Res Dev Disabil 2013; 34:1897-1905. [PMID: 23584170 DOI: 10.1016/j.ridd.2013.02.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 02/23/2013] [Accepted: 02/24/2013] [Indexed: 06/02/2023]
Abstract
The aim of this study was to investigate orthostatic reactions in females with Rett syndrome (RTT), and also whether the severity of the syndrome had an impact on autonomic reactions. Based on signs of impaired function of the central autonomic system found in RTT, it could be suspected that orthostatic reactions were affected. The orthostatic reactions in 21 females with RTT and 14 normally developed females matched by age were investigated when they rose from a sitting position, and during standing for 3 min. Reactions of the heart, the blood pressure and the time for recovery of systolic blood pressure, were studied in real time, heartbeat by heartbeat, simultaneously. There was no difference between participants with RTT and the normally developed controls regarding general orthostatic reactions (heart rate, systolic and diastolic blood pressure, and mean arterial pressure) when getting up from a sitting position, and when standing erect for 3 min. In the specific immediate response by the heart to standing up, the 30:15 ratio, significantly lower values were found for females with RTT. In the RTT group, the maximum fall of systolic blood pressure showed a tendency to a larger decrease, and the initial decrease in systolic blood pressure was significantly faster. The time for recovery of systolic blood pressure from standing erect did not differ between groups. At baseline the females with RTT had significantly lower systolic blood pressure and a tendency to a higher heart rate. The results do not indicate any autonomic limitations for people with RTT in getting up from a sitting position and standing. The participants with RTT had normal orthostatic reactions indicated by the heart and blood pressure responses when standing erect for 3min. A faster initial drop in systolic blood pressure in people with RTT was notable.
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Affiliation(s)
- Gunilla Larsson
- Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden.
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6
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Julu POO, Witt Engerström I, Hansen S, Apartopoulos F, Engerström B. Treating hypoxia in a feeble breather with Rett syndrome. Brain Dev 2013; 35:270-3. [PMID: 22617859 DOI: 10.1016/j.braindev.2012.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 04/23/2012] [Accepted: 04/25/2012] [Indexed: 02/04/2023]
Abstract
Rett syndrome (RS) is a unique X-linked dominant neurodevelopmental disorder affecting 1 in 10,000 females. Mutations in the MECP2 gene located on Xq28 have been identified. Many of the characteristic features evolve due to immaturity of the brain in RS. Cardiorespiratory function should be investigated early to characterise the clinical phenotype of the person with RS because each of the three cardiorespiratory phenotypes; apneustic, feeble and forceful breathers have unique and different management strategies. We report a case of a feeble breather showing a correlation between cortical function and tissue pO(2) and pCO(2). We conclude that subtle changes in the levels of blood gases significantly affect cortical function in RS.
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Affiliation(s)
- Peter O O Julu
- Breakspear Medical Group, Hertfordshire, United Kingdom.
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7
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Pini G, Bigoni S, Engerström IW, Calabrese O, Felloni B, Scusa MF, Di Marco P, Borelli P, Bonuccelli U, Julu POO, Nielsen JB, Morin B, Hansen S, Gobbi G, Visconti P, Pintaudi M, Edvige V, Romanelli A, Bianchi F, Casarano M, Battini R, Cioni G, Ariani F, Renieri A, Benincasa A, Delamont RS, Zappella M. Variant of Rett syndrome and CDKL5 gene: clinical and autonomic description of 10 cases. Neuropediatrics 2012; 43:37-43. [PMID: 22430159 DOI: 10.1055/s-0032-1308856] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
UNLABELLED Rett syndrome (RTT) is a severe neurodevelopmental disorder affecting almost exclusively females. The Hanefeld variant, or early-onset seizure variant, has been associated with mutations in CDKL5 gene. AIMS In recent years more than 60 patients with mutations in the CDKL5 gene have been described in the literature, but the cardiorespiratory phenotype has not been reported. Our aim is to describe clinical and autonomic features of these girls. METHODS 10 girls with CDKL5 mutations and a diagnosis of Hanefeld variant have been evaluated on axiological and clinical aspects. In all subjects an evaluation of the autonomic system was performed using the Neuroscope. RESULTS Common features were gaze avoidance, repetitive head movements and hand stereotypies. The autonomic evaluation disclosed eight cases with the Forceful breather cardiorespiratory phenotype and two cases with the Apneustic breather phenotype. CONCLUSIONS The clinical picture remains within the RTT spectrum but some symptoms are more pronounced in addition to the very early onset of seizures. The cardiorespiratory phenotype was dominated by Forceful breathers, while Feeble breathers were not found, differently from the general Rett population, suggesting a specific behavioral and cardiorespiratory phenotype of the RTT the Hanefeld variant.
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Affiliation(s)
- Giorgio Pini
- Tuscany Rett Centre Versilia Hospital, Lido di Camaiore, Italy.
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8
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Halbach NSJ, Smeets EEJ, Bierau J, Keularts IMLW, Plasqui G, Julu POO, Engerström IW, Bakker JA, Curfs LMG. Altered carbon dioxide metabolism and creatine abnormalities in rett syndrome. JIMD Rep 2011; 3:117-24. [PMID: 23430883 PMCID: PMC3509869 DOI: 10.1007/8904_2011_76] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 06/24/2011] [Accepted: 07/04/2011] [Indexed: 03/23/2024] Open
Abstract
Despite their good appetite, many females with Rett syndrome (RTT) meet the criteria for moderate to severe malnutrition. Although feeding difficulties may play a part in this, other constitutional factors such as altered metabolic processes are suspected. Irregular breathing is a common clinical feature, leading to chronic respiratory alkalosis or acidosis. We assumed that these changes in intracellular pH cause disturbances in the metabolic equilibrium, with important nutritional consequences. The study population consisted of a group of thirteen well-defined RTT girls with extended clinical, molecular and neurophysiological assessments. Despite normal levels of total dietary energy and protein intakes, malnutrition was confirmed based on significantly low fat-free mass index (FFMI) values. Biochemical screening of multiple metabolic pathways showed significantly elevated plasma creatine concentrations and increased urinary creatine/creatinine ratio in five RTT girls. Four girls, 10 years and older, were forceful breathers, one 13-year-old girl had an undetermined cardiorespiratory phenotype. An isolated increase of the urinary creatine/creatinine ratio was seen in two girls, a 9-year old forceful and a 4-year old feeble breather. Given that the young girls are feeble breathers and the older girls are forceful breathers, it is impossible to determine whether the elevated creatine concentrations are due to increasing age or cardiorespiratory phenotype. Furthermore, MeCP2 deficiency may cause epigenetic aberrations affecting the expression of the creatine-transporter gene, which is located at Xq28. Further studies are required to confirm these findings and to provide greater insight into the pathogenesis of the abnormal creatine metabolism in RTT.
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Affiliation(s)
- Nicky S J Halbach
- Department of Clinical Genetics, Maastricht University Medical Centre, P. Debeyelaan 25, 5800, 6202, AZ, Maastricht, The Netherlands,
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9
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Smeets EEJ, Julu POO, van Waardenburg D, Engerström IW, Hansen S, Apartopoulos F, Curfs LMG, Schrander-Stumpel CTRM. Management of a severe forceful breather with Rett syndrome using carbogen. Brain Dev 2006; 28:625-32. [PMID: 16765005 DOI: 10.1016/j.braindev.2006.04.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 08/20/2005] [Accepted: 04/13/2006] [Indexed: 10/24/2022]
Abstract
We have used a novel neurophysiological technique in the NeuroScope system in combination with conventional electroencephalography (EEG) to monitor both brainstem and cortical activity simultaneously in real-time in a girl with Rett syndrome. The presenting clinical features in our patient were severe sleep disturbances, irregular breathing in the awake state dominated by Valsalva's type of breathing followed by tachypnoea and very frequent attacks of seizures and vacant spells. Our novel neurophysiological data showed that the patient was a Forceful Breather according to the breathing categories in Rett syndrome. She had frequent abnormal spontaneous brainstem activation (ASBA) preceded by severe attacks of hypocapnoea, which was caused by a combination of Valsalva's type of breathing and tachypnoea and all these together were responsible for the seizures and non-epileptic vacant spells. The ASBA was not detectable in conventional EEG and there were no epileptiform changes in the EEG during the seizures and vacant spells caused by the hypocapnic attacks, therefore these were pseudo-seizures. The record of brainstem activity confirmed that these were autonomic events, a kind of "brainstem epilepsy". We successfully treated the sleep disturbance with Pipamperone, a 5-hydroxytryptophan antagonist of receptor type 2 and we prevented the severe hypocapnoea during Valsalva's type of breathing and during tachypnoea using carbogen (a mixture of 5% carbon dioxide and 95% oxygen), which we gave by inhalation. Our treatment drastically reduced the autonomic events, promoted whole night sleep and significantly improved the quality of life in our patient. She can now participate in normal family activity which was previously impossible before treatment.
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Affiliation(s)
- Eric E J Smeets
- Department of Clinical Genetics, Academic Hospital Maastricht, Maastricht, The Netherlands.
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10
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Julu POO, Witt Engerström I. Assessment of the maturity-related brainstem functions reveals the heterogeneous phenotypes and facilitates clinical management of Rett syndrome. Brain Dev 2005; 27 Suppl 1:S43-S53. [PMID: 16182494 DOI: 10.1016/j.braindev.2005.02.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Revised: 10/01/2004] [Accepted: 02/22/2005] [Indexed: 10/25/2022]
Abstract
We have investigated whether brainstem assessment using the Neuro Scope could be used for objective and quantitative monitoring of early development and later progress in Rett syndrome. Brainstem features can be seen on bedside examination of Rett patients and are included in the International Scoring system. The following cardiovascular vital signs were recorded simultaneously in real-time: cardiac vagal tone (CVT), cardiac sensitivity to baroreflex (CSB), heart rate (HR), and mean arterial blood pressure (MAP) and respiratory vital signs: breathing rate and pattern, transcutaneous partial pressures of oxygen (pO(2)) and carbon dioxide (pCO(2)). We assessed the occipito-frontal head circumference (OFHC), height and body mass index (BMI). Results are from 72 patients with classical Rett syndrome studied at the Swedish National Rett Centre. Three cardiorespiratory phenotypes, designated Forceful, Feeble and Apneustic breathers were present in similar proportions in the Rett population but early development measured by OFHC and BMI differed. Height was not affected. Baseline levels of CVT and CSB also differed within the phenotypes indicating differences in parasympathetic activities. However, parasympathetic activity in the whole population was similar to that previously reported in Rett. Baseline levels of MAP and HR were similar across the phenotypes, consistent with previous reports of little effect of Rett disorder on baseline sympathetic tone. Adverse responses to opiate analgesics and hypocapnoeic attacks were unique to specific phenotypes. We recommend early characterisation of these phenotypes in the management of Rett syndrome. We conclude that classical Rett syndrome consists of heterogeneous clinical phenotypes with distinct cardiorespiratory states. Brainstem functions can be used to identify these and to monitor development and treatment, thereby facilitating clinical management.
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Affiliation(s)
- Peter O O Julu
- Department of Neurology, Central Middlesex Hospital, Park Royal, London NW10 7NS, UK.
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11
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Ming X, Julu POO, Brimacombe M, Connor S, Daniels ML. Reduced cardiac parasympathetic activity in children with autism. Brain Dev 2005; 27:509-16. [PMID: 16198209 DOI: 10.1016/j.braindev.2005.01.003] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Revised: 12/27/2004] [Accepted: 01/07/2005] [Indexed: 11/27/2022]
Abstract
Many of the clinical symptoms of autism suggest autonomic dysfunction. The aim of this study was to measure baseline cardiovascular autonomic function in children with autism using the NeuroScope, a device that can measure this brainstem function in real-time. Resting cardiac vagal tone (CVT), cardiac sensitivity to baroreflex (CSB), mean arterial blood pressure (MAP), diastolic blood pressure (DBP), systolic blood pressure (SBP) and heart rate (HR) were recorded in three different groups of children. The symptomatic group (n = 15) consisted of those with autism who exhibited symptoms or signs of autonomic dysfunction. The asymptomatic group (n = 13) consisted of children with autism but without symptoms or signs of autonomic dysfunction and the healthy children were in the control group (n = 17) [corrected]. The CVT and CSB were significantly lower in association with a significant elevation in HR, MAP and DBP in all children with autism compared with the healthy controls. Further more, the levels of CVT and CSB were lower in the symptomatic than in the asymptomatic group. The levels of CVT and CSB were not related to age in all the three groups. These results suggest that there is low baseline cardiac parasympathetic activity with evidence of elevated sympathetic tone in children with autism whether or not they have symptoms or signs of autonomic abnormalities.
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Affiliation(s)
- Xue Ming
- Department of Neuroscience, New Jersey Medical School, UMDNJ, Newark, 90 Bergen Street, DOC 8100, NJ 07103, USA.
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12
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Abstract
In dogs with spontaneous heart disease, an electronically generated measurement of cardiac vagal tone, the cardiac index of parasympathetic activity, was a sensitive, simple and inexpensive measure of the severity of heart failure. Dogs with cardiac disease and an index score less than 3 were at 15.8 (95 per cent confidence interval 2.9 to 87.2) times the risk of dying within a year than those with a score of 3 and over. The measurement of the index provided an objective and reliable beat-by-beat measurement of cardiac vagal tone, which was prognostically useful in dogs with heart disease.
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Affiliation(s)
- C J L Little
- Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Bearsden, Glasgow G61 1QH
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13
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Ming X, Julu POO, Wark J, Apartopoulos F, Hansen S. Discordant mental and physical efforts in an autistic patient. Brain Dev 2004; 26:519-24. [PMID: 15533653 DOI: 10.1016/j.braindev.2004.02.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2003] [Revised: 01/21/2004] [Accepted: 02/13/2004] [Indexed: 10/26/2022]
Abstract
We investigated whether there was mental effort in response to verbal commands in a 16-year old girl with autism, a high degree of non-compliance with commands and symptoms of autonomic dysfunction by monitoring the brainstem autonomic tone during an attempt to perform isometric exercise. An index of cardiac vagal tone (CVT), cardiac sensitivity to baroreflex (CSB), heart rate (HR) and mean arterial blood pressure (MAP) were measured simultaneously. Physical non-compliance with our commands meant there was no force applied by the patient during the attempted exercise, but CVT and CSB were both reduced and sustained at very low levels throughout the attempt, while MAP and HR were increased concurrently to higher levels in the same period. This vagal withdrawal to allow concurrent increases in HR and MAP is an arousal response appropriate for isometric exercise, which is a sign of a positive mental effort to comply with our commands. These results demonstrate discordant mental and physical efforts in our patient. In this particular case, the physical inabilities in some instances could have been mislabelled as mental non-compliance due to autism. It would be worthwhile to investigate the prevalence of discordant mental and physical efforts in autism.
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Affiliation(s)
- Xue Ming
- Department of Neuroscience, UMDNJ-New Jersey Medical School, MSB-H506 185 South Orange Avenue, Newark, NJ, USA.
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14
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Abstract
To study cardiovascular control in the period leading to vasovagal syncope we monitored beat-to-beat blood pressure, heart rate (HR) and forearm blood flow in 14 patients with posturally related syncope, from supine through to tilt-induced pre-syncope. Signals of arterial blood pressure (BP) from a Finapres photoplethysmograph and an electrocardiograph (ECG) were fed into a NeuroScope system for continuous analysis. Non-invasive indices of cardiac vagal tone (CVT) and cardiac sensitivity to baroreflex (CSB) were derived on a beat-to-beat basis from these data. Brachial vascular resistance (VR) was assessed intermittently from brachial blood flow velocity (Doppler ultrasound) divided by mean arterial pressure (MAP). Patients underwent a progressive orthostatic stress test, which continued to pre-syncope and consisted of 20 min head-up tilt (HUT) at 60 deg, 10 min combined HUT and lower body suction (LBNP) at -20 mmHg followed by LBNP at -40 mmHg. Pre-syncope was defined as a fall in BP to below 80 mmHg systolic accompanied by symptoms. Baseline supine values were: MAP (means +/- S.E.M.) 84.9 +/- 3.2 mmHg; HR, 63.9 +/- 3.2 beats min-1; CVT, 10.8 +/- 2.6 (arbitrary units) and CSB, 8.2 +/- 1.6 ms mmHg-1. HUT alone provoked pre-syncope in 30 % of the patients whilst the remaining 70 % required LBNP. The cardiovascular responses leading to pre-syncope can be described in four phases. Phase 1, full compensation: where VR increased by 70.9 +/- 0.9 %, MAP was 89.2 +/- 3.8 mmHg and HR was 74.8 +/- 3.2 beats min-1 but CVT decreased to 3.5 +/- 0.5 units and CSB to 2.7 +/- 0.4 ms mmHg-1. Phase 2, tachycardia: a progressive increase in heart rate peaking at 104.2 +/- 5.1 beats min-1. Phase 3, instability: characterised by oscillations in BP and also often in HR; CVT and CSB also decreased to their lowest levels. Phase 4, pre-syncope: characterised by sudden decreases in arterial blood pressure and heart rate associated with intensification of the symptoms of pre-syncope. This study has given a clearer picture of the cardiovascular events leading up to pre-syncope. However, the mechanisms behind what causes a fully compensated system suddenly to become unstable remain unknown.
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Affiliation(s)
- P O O Julu
- Institute for Cardiovascular Research, University of Leeds, UK.
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15
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Abstract
A large number of published studies support the notion that long term, low level (LTLL) exposure to organophosphorus (OP) esters may cause neurological and neurobehavioral effects. In order to differentiate these from other effects of OP such as the acute cholinergic episodes, intermediate syndrome and organophosphate induced delayed neuropathy (OPIDN), the term Chronic Organophosphate Induced Neuropsychiatric Disorder (COPIND) will be used purely for the ease of reference. The question addressed in this particular review is whether LTLL exposure to OP may produce neurotoxicity. The profile and the degree of overlap of the various components of COPIND have been addressed elsewhere and description of the possible mechanisms for COPIND is outside the scope of this article. COPIND can be classified under two headings; those produced following one or more acute clinical cholinergic episodes, and those produced without such preceding attacks. With regards to the first group, there are a total of 11 studies, all of which support the existence of a positive link between exposure to OP and neurotoxicity; six of these studies comprise descriptions of large numbers of cases without controls while five additional studies employ controls. Appearance of neurotoxicity does not seem to be related to the number or the intensity of acute cholinergic attacks. With regards to the second group, three types of studies can be identified. Firstly, there are five studies using experimental animals, all of which showed a positive link between OP and neurotoxicity. Secondly, a total of seven case studies without controls, some involving large numbers of patients, concluded that there is a positive link between OP and neurotoxicity. Thirdly, 19 studies investigated such a link using cases and control groups. Of these, 15 studies (about 80%) showed a positive link and only four failed to identify any link between OP and neurotoxicity. Annotation of all the 19 studies according to ideal set of criteria showed that only a few of these comply with the rules of excellence and all of these few showed a positive link. Furthermore, the only study carried out blind without the identification of subjects or controls, showed a positive link between OP and neurotoxicity. This blind study estimated the overall incidence of a form of neurotoxicity in people exposed to OP to be about 40 times higher than in the general population. The type of neurological involvement was unique and different from OP induced syndromes previously described. The profile of the neurological involvement was similar to that in COPIND whether or not preceded by acute cholinergic episodes, thus providing further evidence that these two neuropathies probably share a similar mechanism. There is a characteristic pattern of involvement of 15 functional indices of the autonomic nervous system examined in our laboratory. There are, in addition, preferential anatomical sites of target organs affected, selective preservation of cholinergic function within the same neuropathy-positive site, and evidence of mal-function of cardiac chemoreceptors in patients exposed to OP. The peripheral nerve involvement in OP exposure is predominantly sensory in nature affecting both small and large fibre populations. Neurobehavioral involvement of mainly cognitive dysfunction and other features are also described in other studies. The weight of current evidence is therefore very much in favor of the motion that chronic low-level exposure to OP produces neurotoxicity. Criticisms levelled against this motion are unfounded and probably misconceived.
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Affiliation(s)
- Goran A Jamal
- Division of Neurosciences, Imperial College of Science, Technology and Medicine, University of London, London, UK.
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16
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Jamal GA, Hansen S, Pilkington A, Buchanan D, Gillham RA, Abdel-Azis M, Julu POO, Al-Rawas SF, Hurley F, Ballantyne JP. A clinical neurological, neurophysiological, and neuropsychological study of sheep farmers and dippers exposed to organophosphate pesticides. Occup Environ Med 2002; 59:434-41. [PMID: 12107290 PMCID: PMC1740317 DOI: 10.1136/oem.59.7.434] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To classify clinical diseases of the subjects with abnormal indices of peripheral neuropathy identified in field studies of sheep farmers and dippers exposed to organophosphate pesticides. To explore what neuropsychological profiles, if any, may be associated with neurophysiological damage in these subjects. METHODS A case-control study (79 subjects) nested within the cross sectional study (685 subjects) of sheep farmers from the field study. Three groups with no, possible, and probable or definite neuropathy according to field studies were recruited. Investigations comprised symptoms of neuropathy, neurologial signs, motor and sensory nerve conduction, electromyography, quantitative sensory testing, and neuropsychological tests. RESULTS The incidence of clinical neuropathy increased from 7% in the no neuropathy group to 52% in the probable or definite neuropathy group based on nerve conduction measurements or presence of neurological signs. Sensory abnormalities were found more often than motor deficits. Small diameter nerve fibres were also affected more than large fibres. CONCLUSIONS The neuropathy is predominantly sensory and is characteristic of distal, chronic neuropathy with no acute features. Small fibre populations are affected more than large fibre populations. Increasing severity of neuropathy was associated with anxiety and depression as measured in the neuropsychological tests.
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Affiliation(s)
- G A Jamal
- Imperial College School of Medicine, London, UK
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