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PubMed1985

Twelve-year experience with bilateral internal mammary artery grafts.

A 12 1/2-year experience with 227 patients who underwent coronary revascularization with bilateral internal mammary artery (IMA) and supplemental saphenous vein grafts is presented. There were 725 coronary grafts performed (3.2 per patient). Forty-four IMA grafts were sequential. In 42 patients, the right IMA was placed through the transverse sinus to revascularize the circumflex artery. Operative mortality was 4% (9 of 227 patients). Postoperative complications included sternal infection (4 patients), reexploration for bleeding (5), and diaphragmatic dysfunction (10). Postoperative arteriography in 30 patients (mean interval, 4 1/4 years) revealed that 92% (34/37) of the left IMA and 87% (26/30) of the right IMA grafts were patent. Late follow-up was complete in 207 surviving patients. Eighteen late deaths (9 cardiac and 9 noncardiac) occurred. Actuarial survival was 83% at 10 years after operation. Of 68 patients followed from 8 to 12 1/2 years (mean interval, 10 1/2 years), 69% were asymptomatic, and 28% were in New York Heart Association Functional Class II. We conclude that bilateral IMA grafting can be accomplished with low operative risk and provides excellent long-term results.

Actuarial Analysis↗

PubMed2000

Neurodevelopmental outcome at 3.5 years of age in children treated with extracorporeal life support: relationship to primary diagnosis.

OBJECTIVE: Recent studies suggest that for neonates treated with extracorporeal membrane oxygenation (ECMO), children with congenital diaphragmatic hernia (CDH) have poorer neurodevelopmental outcome than children with other diagnoses. We therefore analyzed the neurodevelopmental outcome at 3(1/2) years of age in 130 neonatal ECMO survivors with 6 different primary diagnoses. STUDY DESIGN: Children were assessed with the McCarthy Scales of Children's Abilities, Peabody Picture Vocabulary Test, Vineland Adaptive Behavior Scales, and a neurologic/physical examination; 12 factors related to infant characteristics and ECMO/hospital course including primary diagnosis were identified as independent variables. Dependent variables included test scores and 2 outcome categories: functional status (normal, risk, abnormal) and major neurologic sequelae (presence or absence). Statistical tools included chi-squared analysis, t test, analysis of variance, and discriminant and regression analysis. RESULTS: No significant differences were found between diagnostic groups in functional status or neurologic sequelae. Hospital days was the only variable consistently expressed in all analyses as having significant influence on the outcome measures. This was not a factor of the longer hospital days experienced by children with CDH. CONCLUSION: Neurodevelopmental outcome in neonatal ECMO is multifactorial. Although hospital days has the greatest association with outcome at age 3(1/2) years, these days likely reflect degree of illness and various complications that are independent of diagnostic group. Further study is required to determine which factors influencing the length of hospital stay may be the best predictor of long-term outcome.

Age Factors↗

PubMed1998

The collaborative UK ECMO (Extracorporeal Membrane Oxygenation) trial: follow-up to 1 year of age.

OBJECTIVE: To evaluate the clinical effectiveness of neonatal extracorporeal membrane oxygenation (ECMO), in terms of mortality and morbidity, in the treatment of cardiorespiratory failure in term infants. METHODS: The criteria for trial entry were: an oxygenation index of >40 or arterial partial pressure of carbon dioxide (PaCO2) >12 kPa for at least 3 hours; gestational age at birth of 35 completed weeks or more; a birth weight of 2 kg or more; <10 days high-pressure ventilation; an age of <28 days; and no contraindication to ECMO such as previous cardiac arrest or intraventricular hemorrhage. Eligible infants were randomized either to be transferred to one of five ECMO centers in the United Kingdom or to continue conventional treatment. The principal outcome was death or severe disability at the age of 1 year. Severe disability was defined as an overall developmental quotient of <50 using the Griffiths Mental Development Scales, or blindness or a level of function so as to make assessment using the Griffiths Scales impossible. Families of surviving children were contacted at regular intervals during the first year and at the age of 1, and an assessment of the child was performed by one of three developmental pediatricians. This included a neurologic examination, assessment of hearing and vision, developmental level, general health, and health service use. RESULTS: Of 185 infants recruited into the trial, 93 infants were in the ECMO arm and 92 were allocated conventional treatment. The groups were comparable at trial entry. Thirty of 93 (32%) ECMO infants died before the age of 1 year and 54 of 92 (59%) of the infants in the conventional group died. Two infants were lost to follow-up, 1 from each arm of the trial. Of the remaining 99 survivors, at the age of 1 year, 2 infants (1 in each arm) were still in the hospital, and 5 (3 in the ECMO arm and 2 conventional) still required supplementary oxygen. Fifteen infants had tone changes in the limbs, 10/62 (16%) in the ECMO arm and 5/37 (13.5%) in the conventional arm. These signs were more common on the left side in both groups. One infant (in the ECMO arm) had bilateral sensorineural deafness and 1 infant (also in the ECMO arm) had low vision. Overall, 2 infants were severely disabled (1 ECMO and 1 conventional), 16 others also had evidence of functional loss (12 vs 4), and 8 had impairment without functional loss (4 vs 5). There was a trend toward proportionately greater respiratory morbidity in the conventional group. Neurologic morbidity was more common in the ECMO group, reflecting the larger number of survivors. The lower rate of adverse primary outcome (death or severe disability at 1 year) was found among infants allocated ECMO in all the predefined stratified analyses. Disease severity at trial entry and type of referral center did not appear to alter the effects of ECMO. Only 4 of 18 infants with congenital diaphragmatic hernia survived and at age 1 year only 1 of the 4 survivors was considered normal. CONCLUSION: These results are in accord with the earlier preliminary findings that a policy of ECMO support reduces the risk of death without a concomitant rise in severe disability. However, 1 in 4 survivors had evidence of impairment with or without disability. Further follow-up is planned at the age of 4 and 7 years.

Developmental Disabilities↗

PubMed1985

The spleen: development and functional evaluation.

Despite the fact that the spleen has multiple functions, only one has been widely used for evaluation of the organ by imaging techniques (phagocytosis of 99mTc sulfur colloid). The usual splenic uptake of this radiocolloid can by used to determine the size, location, and integrity of the organ. A major use of splenic radiocolloid imaging has been in the study of congenital defects. Thus, eventration of the diaphragm, accessory spleens, splenogonadal fusion, the asplenia and polysplenia syndromes, and the wandering spleen are amenable to study by means of intravenously administered radiocolloid. Interference with the splenic uptake of radiocolloid can be either focal or generalized (as in functional asplenia). Imaging of the spleen has a major role in evaluating suspected trauma of the organ and in following its clinical course. The return of splenic function after splenectomy (splenosis or accessory spleens) can be documented by radionuclide imaging, and likely by hematologic techniques when the volume of tissue is sufficiently large. The detection of intrasplenic lesions is important in tumor staging and as an alerting sign to an ongoing process.

Abscess↗

PubMed2006

Preservation of pleural integrity in patients undergoing coronary artery bypass grafting: effect on postoperative bleeding and respiratory function.

OBJECTIVE: The purpose of this study was to evaluate the influence of preserved integrity of pleura on postoperative bleeding and respiratory function in patients undergoing coronary artery bypass grafting (CABG). METHODS AND RESULTS: Seventy-two CABG patients who received pedunculated IMA graft without opening the pleura (group of intact pleura, group IP) between July 2002 and September 2004 were matched to 72 CABG patients who received pedunculated IMA graft with opened pleura (group of opened pleura, group OP). To match the patients with IP and unique patients with OP, logistic regression was used to develop a propensity score. The C statistic for this model was 0.79. Patients with IP were matched to unique patients with OP with an identical 5-digit propensity score. If this could not be done, we proceeded to a 4-, 3-, 2-, or 1-digit match. Patients characteristics were well matched. There were no differences in preoperative and peroperative variables between the groups. The incidence of postoperative pleural effusion and thoracentesis were significantly lower in group IP than group OP (pleural effusion in 15.2 versus 30.5%; p = 0.029, thoracentesis in 5.5 versus 18.5%; p = 0.036). Other pulmonary complications such as prolonged ventilation, reintubation, pneumothorax, atelectasis, diaphragmatic paralysis were similar in both groups. Patients with IP had significantly lower blood loss (520 versus 870 ml; p < 0.001) and whole blood unit transfusion (26.3 versus 41.6%, p = 0.036). Also, intensive care unit and hospital stay were similar in both groups. CONCLUSIONS: Meticulous internal mammary artery harvesting and preservation of the pleural integrity significantly reduces postoperative bleeding and pleural effusion.

Chi-Square Distribution↗

PubMed2002

Idiopathic bilateral diaphragmatic paralysis.

A 41-year-old man complained of subacute onset of dyspnea and pain in the neck and chest. He was diagnosed with bilateral diaphragmatic paralysis, based on clinical inspection of the breathing pattern and transdiaphragmatic pressure recording, and was trained to use a portable bi-level positive airway pressure apparatus (BiPAP). Needle electromyography showed profuse fibrillation potentials and positive waves in the diaphragm, more abundant on the right than left side, and no response to phrenic nerve stimulation. Other muscles were not involved. Follow-up examinations, performed at 9 and 12 months after onset of paralysis, demonstrated a slow but progressive improvement of the patient's respiratory function, together with the appearance of reinnervation potentials in the diaphragm, and polyphasic, long-latency responses to phrenic nerve stimulation. The subacute onset of the paralysis associated with local pain, and its subsequent recovery, suggest bilateral proximal lesions in the phrenic nerves. In the absence of traumatic or metabolic causes, these findings suggest that the phrenic nerve can be a target in idiopathic neuritis.

Action Potentials↗

PubMed1995

Reverse, innervated latissimus dorsi flap reconstruction of congenital diaphragmatic absence.

Children with congenital diaphragmatic absence have experienced a high mortality rate regardless of early intervention due to regression to fetal circulation patterns. Advances in neonatal care, particularly extracorporeal membrane oxygenation, have led to the survival of children who previously would not have lived. With growth, the Gore-Tex patch used for emergency repair in severe cases pulls away from the rib periosteum as a result of the expansile growth of the chest wall and the indistensibility of the patch. Recurrent herniation of abdominal contents ensues, slowly restricting pulmonary function and development. When pulmonary function is significantly impaired, we perform a reverse latissimus dorsi flap reconstruction with anastomosis of the thoracodorsal nerve to the phrenic nerve. Our series includes five children aged 5 to 11 months. Follow-up ranges from 22 to 50 months. Three children have proven physiologic neodiaphragmatic motion. The other two are doing well with stable absence of paradoxical motion. There have been no complications. Long-term follow-up will be required to determine their eventual fate. The prognosis is encouraging.

Diaphragm↗

PubMed2001

Modeling the kinematics of the canine midcostal diaphragm.

The hypotheses that the chest wall insertion (CW) is displaced laterally during inspiration and that this displacement is essential in maintaining muscle curvature of the costal diaphragmatic muscle fibers were tested. With the use of data from three dogs, caudal, lateral, and ventral displacements of CW during both quiet, spontaneous inspiration and during inspiratory efforts against an occluded airway were observed and recorded. We have developed a kinematic model of the diaphragm that incorporates these displacements. This model describes the motions of the muscle fibers and central tendon; the displacements of the midplane, muscle-tendon junction (MTJ), CW, and center of the muscle fiber-central tendon arcs are modeled as functions of muscle fiber length. In the model, the center of the fiber arcs and MTJ both move caudally parallel to the midplane during inspiration, whereas CW moves both caudally and laterally. The observed lateral displacement of CW and the observed caudal displacement of MTJ, as functions of muscle fiber length, both approximate well the theoretical displacements that would be necessary to maintain curvature of the fiber arcs. In confirming our hypotheses, we have found that lateral displacement of CW is a mechanism by which changes in the shape of the costal diaphragm, as described by its curvature, are limited.

Abdomen↗

PubMed1991

One hundred percent incidence of hemidiaphragmatic paresis associated with interscalene brachial plexus anesthesia as diagnosed by ultrasonography.

Interscalene brachial plexus anesthesia for shoulder surgery routinely includes sensory anesthesia of the fourth and fifth cervical nerves. The authors reasoned that some degree of diaphragm paralysis should result from interscalene blocks that produce surgical C3-C5 sensory anesthesia. In this investigation, ultrasonography was used to study the incidence of ipsilateral hemidiaphragmatic paresis during routine interscalene block, as it is a practical, sensitive, and low-risk method for diagnosing hemidiaphragmatic function without radiation exposure. Thirteen healthy patients received interscalene blocks using a paresthesia technique with 34-52 mL 1.5% mepivacaine with added epinephrine and bicarbonate. All developed cervical sensory anesthesia. Data were collected before and 2, 5, and 10 min after injection, and, when possible (11 of 13 patients), at hourly intervals after surgery. Changes from normal to paradoxical motion of the ipsilateral hemidiaphragm were seen in all 13 patients during sniff and Mueller maneuvers within 5 min (in 11 of 13 patients at 2 min). Diaphragmatic motion returned to normal in 10 of 11 patients between 3 and 4 h after injection and in the remaining patient by the fifth hour after injection. Diaphragmatic paresis appears to be an inevitable consequence of interscalene brachial plexus block when providing anesthesia sufficient for shoulder surgery.

Adult↗

PubMed1995

Respiratory muscle activity in relation to vocalization in flying bats.

The structure of the thoracic and abdominal walls of Pteronotus parnellii (Microchiroptera: Mormoopidae) was described with respect to their function in respiration and vocalization. We monitored electromyographic activity of respiratory and flight muscles in relation to echolocative vocalization. In flight, signals were telemetered with a small FM transmitter modified to summate the low-frequency myopotentials with biosonar signals from a ceramic-crystal microphone. Recordings were also made from the same bats confined to a small cage. Vocalizations were used as the parameter by which all muscle activities were correlated. A discrete burst of activity in the lateral abdominal wall muscles accompanied each vocalization. Diaphragmatic myopotentials occurred between groups of calls and did not coincide with activity of the abdominal wall or with vocalizations. Flight muscles were not active in resting bats. During flight, vocalizations and the abdominal muscle activity that accompanied them coincided with myopotentials of the pectoralis and serratus ventralis muscles. We propose that contractions of the lateral abdominal wall provide the primary power for the production of intense biosonar vocalization in flying and in stationary bats. In flight, synchronization of vocalization with activity of the pectoralis and serratus ventralis jointly contribute to the pressurization of the thoraco-abdominal cavity. This utilization of pressure that is normally generated in flight facilitates respiration and allows for the production of intense vocalizations with little additional energetic expenditure.

Abdominal Muscles↗

PubMed1997

Comparison of magnetic and electrical phrenic nerve stimulation in assessment of phrenic nerve conduction time.

Cervical magnetic stimulation (CMS), a nonvolitional test of diaphragm function, is an easy means for measuring the latency of the diaphragm motor response to phrenic nerve stimulation, namely, phrenic nerve conduction time (PNCT). In this application, CMS has some practical advantages over electrical stimulation of the phrenic nerve in the neck (ES). Although normal ES-PNCTs have been consistently reported between 7 and 8 ms, data are less homogeneous for CMS-PNCTs, with some reports suggesting lower values. This study systematically compares ES- and CMS-PNCTs for the same subjects. Surface recordings of diaphragmatic electromyographic activity were obtained for seven healthy volunteers during ES and CMS of varying intensities. On average, ES-PNCTs amounted to 6.41 +/- 0.84 ms and were little influenced by stimulation intensity. With CMS, PNCTs were significantly lower (average difference 1.05 ms), showing a marked increase as CMS intensity lessened. ES and CMS values became comparable for a CMS intensity 65% of the maximal possible intensity of 2.5 Tesla. These findings may be the result of phrenic nerve depolarization occurring more distally than expected with CMS, which may have clinical implications regarding the diagnosis and follow-up of phrenic nerve lesions.

Adult↗

PubMed2005

Bilateral isolated phrenic neuropathy causing painless bilateral diaphragmatic paralysis.

The authors report four patients with a syndrome of painless bilateral isolated phrenic neuropathy. Electrophysiologic testing demonstrated active denervation restricted to the diaphragm. Long-term recovery was poor. The authors conclude that bilateral isolated phrenic neuropathy is a cause of painless diaphragmatic paralysis distinguishable from immune brachial plexus neuropathy and other neuromuscular disorders with similar clinical presentation.

Adult↗

PubMed1977

[Lung scintigraphy after diphragmatic hernia (author's transl)].

Recuperation of pulmonary function after surgical repair of Bochdaleck's hernia is considered. Gasometric and radiologic features as well as scintigraphy are related in order of prognosis. Of 16 cases, seven had sudden fatal outcome. Survivals achieved total pulmonary recuperation, but some in two to three years.

Hernia, Diaphragmatic↗

PubMed1999

Does myasthenia gravis affect the brain?

Associations between myasthenia gravis (MG) and CNS functions have been made for over 80 years. An increased incidence of psychiatric disorders, epilepsy and multiple sclerosis as well as electroencephalographic (EEG) abnormalities and abnormal evoked responses have been noted in patients with MG. Descriptions of sleep and memory disturbances in MG patients appeared as knowledge accumulated about the role of brain cholinergic systems in sleep and memory. The inference of many of these studies has been that the alleged central cholinergic effects in MG were caused either by the anticholinesterases used to treat MG or by antibodies to muscle nicotinic acetylcholine receptor (nAchR) present in the serum and cerebrospinal fluid (CSF) of MG patients. The antigenic differences between muscle nAchR and neuronal nAchRs, together with the very low concentrations of muscle nAchR antibodies in the CSF, make highly unlikely the claims that CNS cholinergic systems are affected by these muscle antibodies in MG patients. Evoked response abnormalities, if indeed present, are more likely caused by peripheral than central mechanisms, and sleep abnormalities in MG also probably originate in the periphery rather than in the CNS, the result of hypoxia caused by oropharyngeal, intercostal and diaphragmatic muscle weakness which may worsen during sleep, especially during REM sleep. Such hypoxia may account for some of the EEG abnormalities noted in MG patients, but the association of MG with epilepsy appears to be either coincidental or the result of uncontrolled MG. Significant excessive daytime sleepiness resulting from sleep disturbances can also impair memory and the performance of MG patients on neuropsychological tests, as can the presence of mental depression. The psychological aspects of MG can be attributed to the expected consequences of a chronic but unpredictable neuromuscular disease involving weakness of breathing, swallowing, talking, limb and eye movement. Considering the number and variety of claims for direct CNS involvement in MG, the evidence for this is remarkably unconvincing. The quality of MG treatment, both physical and psychological, is a presently undefined variable which might help explain the diametrically opposed results which have been obtained in some of the studies reviewed. Adequate respiratory muscle strength during sleep is an often overlooked peripheral influence upon mental functioning and general well-being of MG patients.

Brain↗

PubMedDate not supplied

Helical CT features of arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC), also known as arrhythmogenic right ventricular dysplasia, is a disorder of the heart muscle of unknown origin. It is characterized by electrical instability of the heart as a result of replacement of the right ventricular myocardium with fatty or fibrous fatty tissue. Dilatation of the right ventricle; fatty tissue in conspicuous trabeculae of the right ventricle, especially in the anterior wall, apex, and inferior (diaphragmatic) wall; and a scalloped appearance (bulging) of the right ventricular wall are characteristic findings at helical computed tomography (CT) that may be used to diagnose ARVC. Fatty tissue in the left ventricle and ventricular septum is seen relatively frequently in ARVC, and fat in the ventricular septum is another useful finding for diagnosis of ARVC with helical CT. ARVC is usually diagnosed on the basis of clinical or pathologic findings, and electron-beam CT is superior to nongated helical CT in assessment of abnormal right ventricular function. However, with knowledge of the characteristic findings, standard nongated helical CT can be helpful in diagnosing ARVC.

Arrhythmogenic Right Ventricular Dysplasia↗

PubMed2005

Diaphragm length and neural drive after lung volume reduction surgery.

RATIONALE: Patients with chronic obstructive pulmonary disease have shorter inspiratory muscles and higher motor unit firing rates during quiet breathing than do age-matched healthy subjects. Lung volume reduction surgery (LVRS) in patients with chronic obstructive pulmonary disease improves lung function, exercise capacity, and quality of life. OBJECTIVES: We studied the effect of LVRS on length and motor unit firing rates of diaphragm and scalene muscles. METHODS: Diaphragm length was estimated by ultrasound and magnetometers, and firing rates were recorded with needle electrodes in patients (five females and seven males) with severe chronic obstructive pulmonary disease, before and after surgery. MEASUREMENTS AND MAIN RESULTS: Pre-LVRS total lung capacity was 135 +/- 10% predicted (mean +/- SD), and FEV1 was 30 +/- 12% predicted. After surgery, median firing frequency of diaphragmatic motor units fell from 17.3 +/- 4.2 to 14.5 +/- 3.4 Hz (p < 0.001), and scalene motor unit firing rates were reduced from 15.3 +/- 6.9 to 13.4 +/- 3.8 Hz (p < 0.001). Tidal volume and diaphragm length change during quiet breathing did not change, but at end expiration, the zone of apposition length of diaphragm against the rib cage (L(Zapp)) increased (30 +/- 28%, p = 0.004). Improvements in quality-of-life measures and exercise performance after surgery were related to increased forced vital capacity and L(Zapp). CONCLUSIONS: Increased diaphragm length resulted in lower motor unit firing rates and reduced breathing effort, and this is likely to contribute to improved quality of life and exercise performance after LVRS.

Aged↗

PubMedDate not supplied

[Coronary arteries in the Macaca fascicularis monkey].

The coronary arterial epicardial network in the monkey Macaca fascicularis was studied. The study concerned 11 hearts of healthy and fertile animals of both sexes. The morphological and morphometric results of the studies performed by microdissection revealed that: In all examined cases of the Macaca fascicularis the heart was supplied by blood through the left and right coronary arteries. The left coronary artery had a larger external diameter (1.2 mm-2.5 mm, average 1.8 mm) than the right one (0.7 mm-1.2 mm, average 0.9 mm). The left coronary artery, with the average length of 4.3 mm (1.8 mm-6.5 mm), usually (82%) ended by bifurcation in to the anterior interventricular and the circumflex branch, and less frequently (18%) by trifurcation forming, in this way, another branch: the left marginal branch. The anterior interventricular branch had the larger external diameter (0.9 mm-1.7 mm, average 1.3 mm) than the circumflex one (0.7 mm-1.7 mm, average 1.1 mm). Most frequently (73%) it could be traced along the diaphragmatic cardiac surface. The circumflex branch usually (73%) terminated as the posterior interventricular branch, and less frequently (9%) as one of the right posterior ventricular branches. The long type of the right coronary artery was observed in 45% of the cases. The presence of the myocardial bridges over the branches of the left coronary artery was found in 54% of the examined hearts. The great resemblance between the Macaca fascicularis subepicardial network with the corresponding one in humans suggest that Macacus fascicularis is a suitable experimental animal for functional studies of the cardiovascular system.

Animals↗

PubMed1995

Dyspnea in dystonia. A functional evaluation.

BACKGROUND: Dystonia consists of action-triggered sustained focal muscle contractions, worsened by effort, and resulting in voice changes, abnormal posturing, and dyspnea. The cause of dyspnea, previously unexplained, is the basis of this report. METHODS: Since the maximal efforts required to perform pulmonary function testing (PFT) could worsen the muscular contractions in dystonic patients, we used several tests to identify possible causes of dyspnea. These included spirometry with flow volume loops (FVL), tidal volume breathing, maximum voluntary ventilation (MVV), and inspiratory and expiratory muscle pressures (PImax, PEmax), sitting and supine. We used cycle ergometry with arterial blood gas (ABG) values to detect cardiac/pulmonary limitations and respiratory inductive plethysmography (RIP) to assess chest wall/abdominal movements for synchrony. Dynamic videofluoroscopy (VF) assessed and recorded the action-triggered muscle activity of the upper airways and the diaphragm during quiet breathing, speech, swallowing, and maximal respiratory maneuvers similar to the efforts required during PFT. RESULTS: Twenty-six dystonic patients, 12 women and 14 men, ages 14 to 70 years (mean age, 52.3 years) were evaluated. Their neurologic classification included 22 primary (idiopathic) and 4 secondary (2 postneuroleptic use, 2 posstraumatic). Four patients originally classified as having focal dystonia had dyspnea and were found to have diaphragmatic and/or upper airway dysfunction too. The PFTs showed abnormal FVL and/or tidal volume breathing patterns, with intermittent interruptions of air flow during inspiration or expiration in 20 of 24 patients. The VF was abnormal in 24 of 26 patients: 19 patients had combined upper airway (UA) and diaphragmatic dysfunction (DD); 1 patient had UA dysfunction alone, and 4 patients had DD alone. Except for poor effort and/or dystonic movements, cycle ergometry was normal in 18 of 21 patients. The ABG values and/or pulse oximetry were normal in 19 of 22 patients. CONCLUSION: Dyspnea in dystonia appears to be due to excessive and/or dysynchronized contractions of the upper airways and/or diaphragm, with usually normal gas exchange. These spasmodic and irregular muscular contractions during speech and daily activities are associated with the sensation of excessive effort to overcome the spasms. Excessive spasms can be triggered during PFT and are best detected on FVL patterns coupled with dynamic VF.

Adolescent↗