RESPIRATORY DYSFUNCTION IN PARKINSON’S DISEASE

Beyond the Brain: Exploring the multi-organ axes in Parkinson's disease pathogenesis

BACKGROUND

Parkinson's Disease (PD), a complex neurodegenerative disorder, is increasingly recognized as a systemic condition involving multi-organ interactions. Emerging evidence highlights roles of organ-brain axes (lung-, liver-, heart-, muscle-, bone-, and gut-brain) in PD pathogenesis. These axes communicate via neural, circulatory, endocrine, and inflammatory pathways, collectively driving neurodegeneration. For example, lung dysfunction in PD involves respiratory impairment and inflammatory signaling, while gut dysbiosis triggers α-synuclein aggregation via the vagus nerve. Such cross-organ interactions underscore PD's systemic nature, challenging traditional brain-centric models.

AIM OF REVIEW

1. Decipher mechanisms linking peripheral organs (e.g., lung, gut) to PD via shared pathways. 2. Explore bidirectional organ-brain interactions (e.g., liver metabolism affecting neurotoxin clearance). 3. Propose multi-organ therapeutic strategies targeting integrated signaling networks. Key Scientific Concepts of Review. 1. Lung-Brain Axis: Respiratory dysfunction (motor impairment, inflammation) exacerbates neurodegeneration. 2. Liver-Brain Axis: Metabolic dysregulation alters neurotoxin clearance; drugs (e.g., levodopa) impact liver function. 3. Heart-Brain Axis: Autonomic dysfunction reduces cerebral blood flow; neuroendocrine changes promote α-synuclein pathology. 4. Muscle-Brain Axis: Neuromuscular/metabolic disruptions worsen motor symptoms. 5. Bone-Brain Axis: Bone-derived hormones (osteocalcin, OCN) and inflammation influence cognition. 6. Gut-Brain Axis: Dysbiosis drives α-synuclein misfolding; gut metabolites modulate neuroinflammation. Integrated Mechanisms: Shared pathways (neuroinflammation, oxidative stress) create a regulatory network, suggesting therapies targeting multi-organ crosstalk (e.g., probiotics, anti-inflammatory agents).

Dyspnea, the silent threat in Parkinson's: a mixed methods study

BACKGROUND

Dyspnea is considered a silent threat to people diagnosed with Parkinson's disease and may be a common concern in patients, however, little is known about how it affects quality of life. This study explored the experiences of independently mobile people who are affected by dyspnea in daily life.

METHODOLOGY

This was a cross-sectional mixed methods study that included an online questionnaire and semi-structured interviews. The participants were included if they were diagnosed with Parkinson's disease; had a self-reported Hoehn and Yahr Score I, II or III; were mobilizing independently; and were Arabic speakers. Participants were excluded if they had any other musculoskeletal, cardiac, respiratory, or neurological diseases; or were previous or current smokers; or had been previously hospitalized due to respiratory complications.

RESULTS

A total of 117 participants completed the Arabic version of the Dyspnea-12 Questionnaire. Dyspnea was reported in all participants and that it had an adverse effect on their quality of life, especially during activities of daily living. Additionally, participants reported a lack of knowledge about pulmonary rehabilitation and were unaware of the availability and potential benefits of participation in programs.

CONCLUSION

Dyspnea was reported in people in the early stages (Hoehn and Yahr Stages I, II, and III) of Parkinson's disease, and may benefit from routine assessment of lung function, dyspnea management and participation in pulmonary rehabilitation.

Neuroanatomical frameworks for volitional control of breathing and orofacial behaviors

Breathing is the only vital function that can be volitionally controlled. However, a detailed understanding how volitional (cortical) motor commands can transform vital breathing activity into adaptive breathing patterns that accommodate orofacial behaviors such as swallowing, vocalization or sniffing remains to be developed. Recent neuroanatomical tract tracing studies have identified patterns and origins of descending forebrain projections that target brain nuclei involved in laryngeal adductor function which is critically involved in orofacial behavior. These nuclei include the midbrain periaqueductal gray and nuclei of the respiratory rhythm and pattern generating network in the brainstem, specifically including the pontine Kölliker-Fuse nucleus and the pre-Bötzinger complex in the medulla oblongata. This review discusses the functional implications of the forebrain-brainstem anatomical connectivity that could underlie the volitional control and coordination of orofacial behaviors with breathing.

Negative pressure pulmonary edema due to upper airway obstruction after general anesthesia in a patient with Parkinson's disease: A case report

In a patient with Parkinson's disease (PD) who underwent spine surgery 13 h after the last anti-Parkinson medications, negative pressure pulmonary edema from upper airway obstruction developed immediately after extubation. Although oxygenation improved with high-flow nasal cannula therapy, such complications might develop due to abrupt discontinuation of medication for PD.

Translation, cross-cultural adaptation, reliability, and construct validity of the Brazilian Portuguese version of the Basic Psychological Needs in Exercise Scale

RESULTS

59 patients were included (61% with COPD and 39% with ILD). BPNES factor scores were not significantly different between raters' assessments (p > 0.05). The internal consistency was 0.70 for autonomy, 0.76 for competence, and 0.80 for relatedness. Inter-rater and test-retest reliability were good to very good for autonomy (ICC = 0.78, 95%CI 0.62-0.87; ICC = 0.75, 95%CI 0.57-0.86, respectively), competence (ICC = 0.81, 95%CI 0.68-0.89; ICC = 0.65, 95%CI 0.43-0.80, respectively), and relatedness (ICC = 0.79, 95%CI 0.65-0.88; ICC = 0.70, 95%CI 0.50-0.83, respectively). Significant correlations were observed between BPNES factors and quality of life, anxiety, depression, and functional status. In conclusion, this study confirmed the reliability and construct validity of the Brazilian Portuguese version of the BPNES in patients with COPD and ILD.

COVID-19 and Parkinson's Disease: Possible Links in Pathology and Therapeutics

The outbreak of SARs-CoV-2 with emerging new variants is leading to global health crisis and has brought a major concern for patients with comorbidities. Parkinson's disease (PD) is a motor neurodegenerative disease involving various metabolic and psychological ailments along with the common occurrence of hyposmia as observed in COVID-19 patients. In addition, the observed surplus inflammatory responses in both diseases are also alarming. Alongside, angiotensin-converting enzyme 2 (ACE2) receptor, essentially required by SARS-CoV-2 to enter the cell and dopamine decarboxylase (DDC), required for dopamine synthesis is known to co-regulate in the non-neuronal cells. Taken together, these conditions suggested the probable reciprocal pathological relation between COVID-19 and PD and also suggested that during comorbidities, the disease diagnosis and therapeutics are critical and may engender severe health complications. In this review, we discuss various events and mechanisms which may have implications for the exacerbation of PD conditions and must be taken into account during the treatment of patients.

Respiratory Abnormalities in Parkinson's Disease: What Do We Know from Studies in Humans and Animal Models?

Parkinson’s disease (PD) is the second most common progressive neurodegenerative disease characterized by movement disorders due to the progressive loss of dopaminergic neurons in the ventrolateral region of the substantia nigra pars compacta (SNpc). Apart from the cardinal motor symptoms such as rigidity and bradykinesia, non-motor symptoms including those associated with respiratory dysfunction are of increasing interest. Not only can they impair the patients’ quality of life but they also can cause aspiration pneumonia, which is the leading cause of death among PD patients. This narrative review attempts to summarize the existing literature on respiratory impairments reported in human studies, as well as what is newly known from studies in animal models of the disease. Discussed are not only respiratory muscle dysfunction, apnea, and dyspnea, but also altered central respiratory control, responses to hypercapnia and hypoxia, and how they are affected by the pharmacological treatment of PD.

Breathing disorders in neurodegenerative diseases

Neurodegenerative disorders are a diverse group of conditions caused by progressive degeneration of neurons resulting in cognitive, motor, sensory, and autonomic dysfunction, leading to severe disability and death. Pulmonary dysfunction is relatively common in these conditions, may be present early in the disease, and is less well recognized and treated than other symptoms. There are variable disorders of upper and lower airways, central control of ventilation, strength of respiratory muscles, and breathing during sleep which further impact daily activities and quality of life and have the potential to injure vulnerable neurons. Laryngopharyngeal dysfunction affects speech, swallowing, and clearance of secretions, increases the risk of aspiration pneumonia, and can cause stridor and sudden death. In Parkinson's disease, L-Dopa benefits some pulmonary symptoms but there are limited pharmacological treatment options for pulmonary dysfunction. Targeted treatments include strengthening of respiratory muscles, positive airway pressure in sleep and techniques to improve cough efficacy. Well-designed clinical trials are needed to evaluate the long-term benefits of these interventions. Challenges for the future include earlier identification of pulmonary dysfunction in the clinic, institution of the most effective treatments (based on clinical trials that measure long-term meaningful outcomes) and the development of neuroprotective treatment.

Dysregulation of Respiratory Center Drive (P0.1) and Muscle Strength in Patients With Early Stage Idiopathic Parkinson's Disease

Objective: The goal of this study is to evaluate pulmonary function and respiratory center drive in patients with early-stage idiopathic Parkinson's disease (IPD) to facilitate early diagnosis of Parkinson's Disease (PD).

Methods: 43 IPD patients (Hoehn and Yahr scale of 1) and 41 matched healthy individuals (e.g., age, sex, height, weight, BMI) were enrolled in this study. Motor status was evaluated using the Movement Disorders Society-Unified PD Rating Scale (MDS-UPDRS). Pulmonary function and respiratory center drive were measured using pulmonary function tests (PFT). All IPD patients were also subjected to a series of neuropsychological tests, including Non-Motor Symptoms Questionnaire (NMSQ), REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ), Beck Depression Inventory (BDI) and Mini Mental State Examination (MMSE).

Results: IPD patients and healthy individuals have similar forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), forced expiratory volume in 1s/forced vital capacity (FEV1/FVC), peak expiratory flow (PEF), and carbon monoxide diffusion capacity (DLCOcSB). Reduced respiratory muscle strength, maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax) was seen in IPD patients (p = 0.000 and p = 0.002, respectively). Importantly, the airway occlusion pressure after 0.1 s (P0.1) and respiratory center output were notably higher in IPD patients (p = 0.000) with a remarkable separation of measured values compared to healthy controls.

Conclusion: Our findings suggest that abnormal pulmonary function is present in early stage IPD patients as evidenced by significant changes in PImax, PEmax, and P0.1. Most importantly, P0.1 may have the potential to assist with the identification of IPD in the early stage.

Pulmonary Safety and Tolerability of Inhaled Levodopa (CVT-301) Administered to Patients with Parkinson's Disease

Background: CVT-301, an inhaled levodopa (LD) formulation, is under development for relief of OFF periods in Parkinson's disease (PD). Previously, we reported that CVT-301 improved OFF symptoms relative to placebo. In this study, we evaluate pulmonary function in patients treated with a single dose of CVT-301 or placebo for 3 hours, or received multiple doses/day for 4 weeks.

Methods: As part of two phase 2 studies, pulmonary safety and tolerability of CVT-301 were evaluated in PD patients experiencing motor fluctuations (≥2 hours OFF/day), Hoehn and Yahr stage 1–3, and forced expiratory volume in 1 second/forced vital capacity ratio ≥75% of predicted (in ON state). In study A, patients received single doses of oral carbidopa/LD and each of the following via the inhaled route: placebo and 25 and 50 mg LD fine particle dose (FPD) CVT-301. In study B, patients received up to 3 inhaled doses/day of 35 mg (weeks 1–2) and 50 mg LD FPD CVT-301 (weeks 3–4) versus placebo. Assessments included spirometry and treatment-emergent adverse events (TEAEs).

Results: In study A, (n = 24) mean age ± standard deviation was 61.3 ± 7.4 years, mean time since diagnosis was 10.5 ± 4.6 years, and mean duration of LD treatment 8.4 ± 3.7 years. Assessment of pulmonary function (predose to 3 hours postdose) showed that spirometry findings were within normal ranges, regardless of treatment groups, or motor status at screening. In study B, (n = 86) mean age was 62.4 ± 8.7 years, time since PD diagnosis was 9.4 ± 3.9 years, and duration of LD treatment 7.8 ± 3.9 years. Longitudinal assessment of pulmonary function over 4 weeks showed no significant difference in spirometry between CVT-301 versus placebo groups. In both studies, the most common CVT-301 TEAE was mild-to-moderate cough (study A: 21%; study B: 7% vs. 2% in placebo). Other common TEAEs in study B were dizziness and nausea.

Conclusion: Acute and longitudinal assessment of pulmonary function showed that CVT-301 treatment was not associated with acute airflow obstruction in this population. CVT-301 was generally safe and well tolerated.

Phrenic and hypoglossal nerve activity during respiratory response to hypoxia in 6-OHDA unilateral model of Parkinson's disease

AIMS

Parkinson's disease (PD) patients apart from motor dysfunctions exhibit respiratory disturbances. Their mechanism is still unknown and requires investigation. Our research was designed to examine the activity of phrenic (PHR) and hypoglossal (HG) nerves activity during a hypoxic respiratory response in the 6-hydroxydopamine (6-OHDA) model of PD.

MAIN METHODS

Male adult Wistar rats were injected unilaterally with 6-OHDA (20μg) or the vehicle into the right medial forebrain bundle (MFB). Two weeks after the surgery the activity of the phrenic and hypoglossal nerve was registered in anesthetized, vagotomized, paralyzed, and mechanically ventilated rats under normoxic and hypoxic conditions. Lesion effectiveness was confirmed by the cylinder test, performed before the MFB injection and 14days after, before the respiratory experiment.

KEY FINDINGS

6-OHDA lesioned animals showed a significant increase in normoxic inspiratory time. Expiratory time and total time of the respiratory cycle were prolonged in PD rats after hypoxia. The amplitude of the PHR activity and its minute activity were increased in comparison to the sham group at recovery time and during 30s of hypoxia. The amplitude of the HG activity was increased in response to hypoxia in 6-OHDA lesioned animals. The degeneration of dopaminergic neurons decreased the pre-inspiratory/inspiratory ratio of the hypoglossal burst amplitude during and after hypoxia.

SIGNIFICANCE

Unilateral MFB lesion changed the activity of the phrenic and hypoglossal nerves. The altered pre-inspiratory hypoglossal nerve activity indicates modifications to the central mechanisms controlling the activity of the HG nerve and may explain respiratory disorders seen in PD, i.e. apnea.

Assessment of the acute effects of different PEP levels on respiratory pattern and operational volumes in patients with Parkinson's disease

The aim of the study was to determine the acute effects of positive expiratory pressure (PEP) on breathing pattern, operational volumes and shortening velocity of respiratory muscles on patients with Parkinson's disease. It was evaluated 15 patients and healthy controls, by optoelectronic plethysmography, using PEP in three different levels (10, 15 and 20cmH2O). Breathing pattern changed in both groups. Parkinson group increased tidal volume in all PEP levels (p<0.001), but with lower values compared to control. End-inspiratory chest wall volume increased in the Parkinson group at all PEP levels (p<0.001), end-expiratory chest wall volume show a slightly increase when we compared QB to all PEP levels in Parkinson's. There was an intergroup difference in the index of shortening velocity of abdominal, diaphragm and inspiratory muscles of the rib cage at all PEP levels (p<0.01). We conclude that Parkinson's disease promotes important alterations in different breathing pattern components and PEP has significant effects on these alterations.

Opposing effects on the phrenic motor pathway attributed to dopamine-D1 and -D3/D2 receptor activation

Previous in vivo studies revealed that dopamine-D1-agonists elevate excitability of ventral respiratory column (VRC) neurons and increase discharge activity in the phrenic motor output through actions in the brainstem. In this in vivo study performed on pentobarbital-anesthetized cats, we show that D1-agonists (SKF-38393, dihydrexidine) given intravenously enhanced discharge activity in VRC inspiratory neurons and the phrenic nerve in two stages; discharge intensity first increased to a peak and then discharge duration increased. Cross-correlation analysis of VRC inspiratory neuron and phrenic nerve discharges showed that both stages increased strength of coupling between medullary inspiratory neurons and the phrenic motoneuron output. Intracellular recording and microiontophoresis experiments indicated that D1-agonists produced their stimulatory effects indirectly through actions on synaptic inputs to VRC inspiratory neurons. Because other laboratories have provided evidence that dopamine acting on other types of receptors depresses respiratory neuron excitability we tested the effects of piribedil, an agonist that activates receptors of the generally depressant D3/D2-dopamine receptor family, on phrenic nerve activity. Piribedil depressed phrenic nerve inspiratory discharge intensity, prolonged discharge duration, slowed burst frequency and slowed rate of action potential augmentation. The effects of piribedil were partially counteracted by intravenous injection of dihydrexidine. We propose that under normal, steady state conditions, D1-receptor-mediated excitatory modulation of phrenic motor output overrides D3/D2-receptor mediated inhibition.

An introduction to dyskinesia--the clinical spectrum

The term movement disorder is used to describe a variety of abnormal movements, and may involve an excess or paucity of movement. Careful characterization of phenomenology is an essential component of diagnosis. Factors such as speed, amplitude, duration, distribution, rhythmicity, suppressibility and pattern of movement provide valuable information to guide the clinician in their assessment of the movement disorder. In this chapter, the clinical spectrum and phenomenology of dyskinesias will be reviewed.

Dysphagia in Parkinson's disease: a therapeutic challenge?

This article focuses on the current status and research directions on swallowing disorders (dysphagia) in patients with Parkinson's disease (PD). Although epidemiological data are scarce, increased incidence of dysphagia in patients with PD leads to increased risk of mortality, secondary to aspiration pneumonia. Although studies show that aspiration pneumonia is a common cause of death in this group of patients, clinical practice lacks an evidence base and there is an increased need for randomized clinical trials. Importantly, the underlying mechanisms accounting for the progression of dysphagia in PD are still unclear. Furthermore, evidence shows that dopaminergic medication does not affect swallowing performance. Future research in the field is urgently needed and may result in improved management of dysphagia in patients with PD.

The close relationship between life-threatening breathing disorders and urine storage dysfunction in multiple system atrophy

Survival of multiple system atrophy (MSA) depends on whether a variety of sleep-related breathing problems as well as autonomic failure (AF) occur. Since the brainstem lesions that cause respiratory and autonomic dysfunction overlap with each other, these critical manifestations might get worse in parallel. If so, the detection of AF, which is comparatively easy, might be predictive of a latent life-threatening breathing disorder. In 15 patients with MSA, we performed autonomic function tests composed of postural challenges and administered a questionnaire on bladder condition, as well as polysomnography and laryngoscopy during wakefulness and under anesthesia. Polysomnographic variables such as the apnea-hypopnea index (AHI) and oxygen saturation (SpO(2)) and the findings of laryngoscopy were compared with the degree of cardiac and urinary autonomic dysfunction. AHI, mean SpO(2) and the lowest SpO(2) showed significant correlations with urine storage dysfunction. In addition, patients with vocal cord abductor paralysis (VCAP) or central sleep apnea (CSA) contributing to nocturnal sudden death had more severe storage disorders than those without. On the other hand, no significant relationship between polysomnographic variables and orthostatic hypotension was observed except in the case of mean SpO(2). These results indicate that life-threatening breathing disorders have a close relationship with AF, and especially urine storage dysfunction. Therefore, longitudinal assessment of deterioration of the storage function might be useful for predicting the latent progress of VCAP and CSA.

Age-related physiologic changes and perioperative management of elderly patients

Aging itself only minimally increases operative risk, but with aging, there is an increase of the prevalence of chronic diseases and a progressive deterioration of organ function. Aging is associated with a progressive decrease in heart, lung and kidney performance. Under normal conditions, these physiologic changes do not produce any problems for the elderly, but when these patients are subjected to the stress of surgery or its complications, there may be inadequate functional reserve. It is very important to know age-related patho-physiological changes in order to be able to better evaluate elderly patients undergoing surgery, and to prevent and manage preoperative complications. In this review we try to identify and to describe the most frequent physiological changes in the elderly, how those impact pharmacodynamic and pharmacokinetic parameters, and how to assess and manage them.

Movement disorder emergencies

Movement disorder emergencies include any movement disorder which evolves over hours to days, in which failure to appropriately diagnose and manage can result in patient morbidity or mortality. It is crucial that doctors recognize these emergencies with accuracy and speed by obtaining the proper history and by being familiar with the phenomenology of frequently encountered movements. These disorders will be discussed based on the most common associated involuntary movement, either parkinsonism, dystonia, chorea, tics or myoclonus, and, when available, review the workup and treatment options based on the current literature.

A pilot study of respiration and swallowing integration in Parkinson's disease: "on" and "off" levodopa

Parkinson's disease is associated with both swallowing and respiratory dysfunction, increasing the risk of aspiration and pneumonia. Previous studies have shown improvements in measurements of swallowing and respiration with levodopa; however, the studies are small and some studies show conflicting reports. The aim of this study was to further investigate the effect of levodopa on respiration. Ten patients with Parkinson's disease were tested "On" and "Off" levodopa. Assessments included Unified Parkinson's Disease Rating Scale (UPDRS), coordination of swallowing and respiration, timed-test of swallowing, lung function testing, and, qualitative assessment of swallowing. There was a nonsignificant trend to lower volume per swallow when "On" levodopa, significant reduction in lung function when "On" levodopa, but no difference in coordination of swallowing and respiration or qualitative assessment of swallowing. There was a significant increase in motor examination score of the UPDRS when "Off" levodopa compared to "On." There may be a reduction in efficiency of swallowing with levodopa medication without any apparent increase in risk of aspiration. These pilot data suggest that further evaluation with larger numbers of participants is justified.

Pulmonary function in multiple sclerosis without any respiratory complaints

OBJECTIVES

Pulmonary complications in severe multiple sclerosis (MS) are often seen secondary to respiratory muscle dysfunction. The development of respiratory muscle dysfunction and its association with disability during the course of MS is unknown. In our study, we investigated the predictive value of respiratory muscle functions and the change in forced vital capacity (Delta forced vital capacity [FVC]; FVC upright-FVC supine) to detect deterioration of respiratory muscle functions in the early phase of MS.

PATIENTS AND METHODS

Twenty-one MS patients with a median age of 34.5+/-9.45 years were enrolled. Fourteen cases were relapsing-remitting, six were secondary progressive, one was primary progressive type. The mean duration of disease was 10.76+/-6.6 years. Seventeen healthy subjects with a median age of 40.7+/-7.6 years were chosen as a control group. Smoking habit was similar in both groups. Pulmonary function tests (PFT), lung volumes, diffusion, respiratory muscle function ( P(Imax) , P(Emax)), mouth occlusion pressure, and indirect sign of respiratory center function (P(0.1)) tests were performed. PFT were repeated in supine and upright positions.

RESULTS

Our results in the MS group and the control group, respectively, were: diffusion (DL(CO): 18.8+/-4.2 vs. 26.4+/-7.3 mL/mmHg/min), P(I(max) (82.1+/-26.3 vs. 109.1+/-23.3 cm H(2)O), P(E(max) (119.2+/-42 vs. 171.8+/-50.2 cm H(2)O), P(0.1) (2.6+/-0.7 vs. 4.2+/-0.7). All parameters were lower in the MS group compared with the control group (p<0.05). In the MS group, FVC values in the upright position were higher than FVC values in the supine position. The difference in FVC values in MS patients between the upright and supine positions (Delta FVC) was also found to be significantly higher than in the control group (Delta FVC 262.3+/-247.6 (MS), 98.8+/-179.1 mL (CONTROL)) (p<0.01).

CONCLUSION

Our results indicate the presence of pulmonary dysfunction in MS even in the absence of any respiratory symptoms.

Aging of the respiratory system: impact on pulmonary function tests and adaptation to exertion

Normal aging of the respiratory system is associated with a decrease in static elastic recoil of the lung, in respiratory muscle performance, and in compliance of the chest wall and respiratory system, resulting in increased work of breathing compared with younger subjects and a diminished respiratory reserve in cases of acute illness, such as heart failure, infection, or airway obstruction. In spite of these changes, the respiratory system remains capable of maintaining adequate gas exchange at rest and during exertion during the entire lifespan, with only a slight decrease in Pa(O2) and no significant change in Pa(CO2).

Patterns of lung volume use during an extemporaneous speech task in persons with Parkinson disease

This study examined patterns of lung volume use in speakers with Parkinson disease (PD) during an extemporaneous speaking task. The performance of a control group was also examined. Behaviors described are based on acoustic, kinematic and linguistic measures. Group differences were found in breath group duration, lung volume initiation, and lung volume termination measures. Speakers in the control group alternated between a longer and shorter breath groups. With starting lung volumes being higher for the longer breath groups and lower for shorter breath groups. Speech production was terminated before reaching tidal end expiratory level. This pattern was also seen in 4 of 7 speakers with PD. The remaining 3 PD speakers initiated speech at low starting lung volumes and continued speaking below EEL. This subgroup of PD speakers ended breath groups at agrammatical boundaries, whereas control speakers ended at appropriate grammatical boundaries.

LEARNING OUTCOMES

As a result of participating in this exercise, the reader will (1) be able to describe the patterns of lung volume use in speakers with Parkinson disease and compare them with those employed by control speakers; and (2) obtain information about the influence of speaking task on speech breathing.

Pneumonia in the very old

Pneumonia is a major medical problem in the very old. The increased frequency and severity of pneumonia in the elderly is largely explained by the ageing of organ systems (in particular the respiratory tract, immune system, and digestive tract) and the presence of comorbidities due to age-associated diseases. The most striking characteristic of pneumonia in the very old is its clinical presentation: falls and confusion are frequently encountered, while classic symptoms of pneumonia are often absent. Community-acquired pneumonia (CAP) and nursing-home acquired pneumonia (NHAP) have to be distinguished. Although there are no fundamental differences in pathophysiology and microbiology of the two entities, NHAP tends to be much more severe, because milder cases are not referred to the hospital, and residents of nursing homes often suffer from dementia, multiple comorbidities, and decreased functional status. The immune response decays with age, yet pneumococcal and influenza vaccines have their place for the prevention of pneumonia in the very old. Pneumonia in older individuals without terminal disease has to be distinguished from end-of-life pneumonia. In the latter setting, the attributable mortality of pneumonia is low and antibiotics have little effect on life expectancy and should be used only if they provide the best means to alleviate suffering. In this review, we focus on recent publications relative to CAP and NHAP in the very old, and discuss predisposing factors, microorganisms, diagnostic procedures, specific aspects of treatment, prevention, and ethical issues concerning end-of-life pneumonia.

Invited review: Neural network plasticity in respiratory control

Respiratory network plasticity is a modification in respiratory control that persists longer than the stimuli that evoke it or that changes the behavior produced by the network. Different durations and patterns of hypoxia can induce different types of respiratory memories. Lateral pontine neurons are required for decreases in respiratory frequency that follow brief hypoxia. Changes in synchrony and firing rates of ventrolateral and midline medullary neurons may contribute to the long-term facilitation of breathing after brief intermittent hypoxia. Long-term changes in central respiratory motor control may occur after spinal cord injury, and the brain stem network implicated in the production of the respiratory rhythm could be reconfigured to produce the cough motor pattern. Preliminary analysis suggests that elements of brain stem respiratory neural networks respond differently to hypoxia and hypercapnia and interact with areas involved in cardiovascular control. Plasticity or alterations in these networks may contribute to the chronic upregulation of sympathetic nerve activity and hypertension in sleep apnea syndrome and may also be involved in sudden infant death syndrome.

Pulmonary physical medicine interventions for elderly patients with muscular dysfunction

The respiratory consequences of respiratory muscle impairment, with or without bulbar muscle weakness, usually involve inadequate ventilation and airway secretion encumbrance and may progress to respiratory failure. This article focuses on muscular dysfunction of the bulbar and respiratory musculature in elderly patients with neuromuscular diseases or central nervous system disorders. In addition, the article discusses application of pulmonary physical medicine principles for patients with predominantly restrictive pulmonary disorders caused primarily by muscular dysfunction. Diagnostic evaluation, respective clinical courses and responses to therapy, and the use of noninvasive ventilatory support outside of an acute care setting are also reviewed.

[Analysis of breathing function in Parkinson's disease]

We studied 40 parkinsonian patients (P), mean age 50-80 years, with Hoehn and Yahr stages I-III and 40 no parkinsonian patients (NP), with similar characteristics. The results of the thoracic amplitude was 1,8+/-0,8cm of P that showed a reduction to 4,3+/-1,0 cm of NP (p=0,00001), the vital capacity and forced vital capacity, 66,8+/-20,3% and 69,6+/-22,2% of P was decreased that 82,3+/-15,7% and 82,7+/-16,6% of NP (p=0,00001 and p=0,0023). There was not difference among the maximal inspiratory and expiratory mouth pressures, 33,5+/-12,7 cmH2O and 36,3+/-17,8 cmH2O of P and 37,0+/-12,2 cmH2O and 43,1+/-16,6 cmH2O of NP (p=0,1753 and p=0,0398), the forced expiratory volume in 1 second, 71,3+/-25,6% of P and 80,6+/-23,6% of NP (p=0,0899), and the forced expiratory volume in 1 second/ forced vital capacity, 104,5+/-19,9% of P and 97,4+/-22,8% of NP (p=0,1234). The parkinsonian patients present restrictive pulmonary dysfunction, low chest wall compliance and the respiratory muscle strength do not decreased.