Respiratory Muscle Training in Subacute Stroke Patients
Respiratory Muscle Training in Subacute Stroke Patients
This study is divided for development in two complementary work packages justified by the
 need to incorporate new strategies to optimize rehabilitation outcomes in stroke patients.
 The general objectives are: 1) to determine the prevalence of respiratory muscle dysfunction
 in stroke patients; 2) to identify the existence of a potential amino acid marker of
 increased risk of muscle dysfunction after suffering a stroke; 3) to evaluate the
 effectiveness of incorporating the respiratory muscle training as an innovative adjuvant
 therapy in stroke rehabilitation program that may decrease the incidence of morbidity and
 mortality in the medium and long term; and 4) to quantify the potential impact of respiratory
 muscle training on the costs of care for stroke patients.
Stroke is a major cause of morbidity and mortality worldwide. It determines a substantial
 socioeconomic burden. Stroke can lead to varying degrees of oropharyngeal dysphagia (25-85%
 of patients) and respiratory muscle dysfunction associated with an increase in medical
 complications such as bronchoaspiration pneumonia, malnutrition and death. The respiratory
 muscle dysfunction is a common functional abnormality in chronic respiratory diseases such as
 chronic obstructive pulmonary disease (COPD), heart failure, multiple sclerosis in which it
 has been shown to modify the expected survival. Dysphagia is present in a significant
 proportion of patients admitted to Rehabilitation (up to 85% depending on series) in the
 subacute phase of stroke. There is no drug able to restore the swallowing function and
 inspiratory and expiratory muscle function in these patients. Consequently, neurological
 rehabilitation is the mainstay of treatment of these disorders.

 Amino acids (AA) are essential for proper protein synthesis. Skeletal muscle represents the
 largest reserve of body AA, which may be used according to metabolic needs. Within this group
 of compounds, the most involved in muscle metabolism are glutamate, aspartate, asparagine,
 valine, leucine and isoleucine. A pathobiological association between decrease in muscle
 glutamate and diaphragm dysfunction in patients with chronic respiratory diseases has been
 demonstrated in chronic respiratory patients. Moreover, glutamate levels of the diaphragm can
 be restored as a result of muscle training, playing a decisive role as a precursor of certain
 AA (glutamine and alanine), and glutathione in patients with COPD. Other studies have defined
 that glutamine may be a biomarker of training response in healthy individuals. Several
 publications have reflected the decrease of glutamine and glutamate as a result of different
 diseases and in some cases have tried to supplement this deficit.

 Muscle dysfunction is defined as a function impairment (decrease in strength and/or
 resistance) of muscles whose main consequence is muscle fatigue. Although exercise training
 has been used successfully to restore function in patients with some chronic illnesses and
 frailty, there is little evidence of the beneficial effects of an overall muscle training in
 stroke patients. Regarding peripheral muscles, a high-intensity training improves strength
 and endurance of lower limbs muscles (paretic and non paretic) in stroke patients.
 Dysfunction of the diaphragm and other respiratory muscles has important clinical
 implications. It associates with susceptibility to hypercapnic ventilatory failure,
 ineffective cough, and even higher incidence of repeated hospital admissions and mortality.
 Therefore, respiratory muscle weakness described in some stroke patients justifies the need
 to train respiratory muscles because there is no general exercise (bicycle, legs, arms) able
 to induce an overload enough to achieve training effect on respiratory muscles.
Inclusion Criteria:

 -  Hemiplegia secondary to first ischemic stroke in the subacute phase, and

 -  informed consent signed by the candidates of the study, after receiving full
 information on objectives, techniques and possible consequences.

 Exclusion Criteria:

 -  Serious cardiovascular, neuromuscular or metabolic conditions that could interfere
 with the results and/or interfere with the measurements,

 -  significant alcohol abuse (> 80 g/day) or severe malnutrition, and

 -  treatment with drugs with potential effect on muscle structure and function (steroids,
 anabolic steroids, thyroid hormones and immunosuppressants).