Direct current stimulation as a non-invasive therapeutic alternative for treating autonomic or non-autonomic neurological disorders affecting breathing

Direct current stimulation (DCS) is a non-invasive approach to stimulate the nervous system that is now considered a powerful tool for treating neurological diseases such as those affecting cognitive or locomotor functions. DCS, as applied clinically today, is an approach built on early uses in antiquity and knowledge gained over time. Its current use makes use of specific devices and takes into account knowledge of the mechanisms by which this approach modulates functioning of the nervous system at the cellular level. Over the last 20 years, although there are few studies, it has been shown that DCS can also modulate the breathing autonomic function. In this narrative review, after briefly providing the historical perspective and describing the principles and the main cellular and molecular effects, we summarize the currently available data regarding the modulation of ventilation, and propose that DCS could be used to treat autonomic or non-autonomic neurological disorders affecting breathing.

Autonomic Dysfunction from Diagnosis to Treatment

Autonomic disorders can present with hypotension, gastrointestinal, genitourinary symptoms, and heat intolerance. Diabetes is the most common causes of autonomic failure, and management should focus on glucose control to prevent developing autonomic symptoms. The most prevalent cause of dysautonomia, or autonomic dysfunction, is Postural Orthostatic Tachycardia Syndrome (POTS). Autonomic testing characterizes causes for nonspecific symptoms but is not necessary in patients with classic presentations. Treatment for autonomic dysfunction and failure focus on discontinuing offending medications, behavioral modification, and pharmacologic therapy to decrease symptom severity. Autonomic failure has no cure; therefore, the focus remains on improving quality of life.

[Diabetic cardiovascular autonomic neuropathy: clinical significance, diagnosis and therapy]

Az autonóm neuropathia a cukorbetegség igen gyakori szövődménye, mely a diabetes kórfejlődése során már korán kialakul, sőt már a csökkent glükóztolerancia stádiumában is jelen lehet. A betegek életminőségére, a cardiovascularis morbiditásra és mortalitásra gyakorolt prognosztikus jelentősége, a többi szövődménnyel mutatott összefüggései miatt a cardiovascularis autonóm funkció károsodása a cukorbetegség szövődményei között kiemelt jelentőségű. A cardiovascularis autonóm neuropathia klinikai manifesztációi mint a nyugalmi tachycardia, az orthostaticus hypotonia, a néma myocardialis ischaemia és infarktus vagy éppen a QT-távolság megnyúlása miatt kialakuló ritmuszavarok mind hozzájárulnak a cardiovascularis autonóm neuropathia rossz prognózisához. Ezek a betegek gyakrabban szenvednek el hirtelen szívhalált, és a perioperatív légzés-keringésleállás kockázata is nagyobb. A szövődmény irányában végzett szűrővizsgálatok így alapvető jelentőségűek. A diagnosztikában a mai napig a hagyományos cardiovascularis reflextesztek tekinthetők arany standardnak, melyek egyszerű, noninvazív, jól reprodukálható, megfelelő szenzitivitással és specificitással rendelkező eszközös vizsgálatok. Az egyéb vizsgálati lehetőségek közül a szívfrekvencia-variabilitás és baroreflex-szenzitivitás a prognózis pontosabb megítélésére, illetve elsősorban klinikai tanulmányokban végpontokként használatosak. Az összefoglaló kitér emellett a betegek előszűrését szolgáló kérdőíves módszerekre és a diagnosztika egyszerűsítését célzó újabb lehetőségekkel kapcsolatos legfrissebb eredményekre. A cardiovascularis autonóm neuropathia kezelésének sarokkövét a megfelelő glykaemiás kontroll és a cardiovascularis kockázati tényezők kontrollja jelenti. További oki terápiás lehetőség az alfa-liponsav alkalmazása, melynek az autonóm funkcióra gyakorolt kedvező hatásait klinikai vizsgálat igazolta. A hagyományos értelemben vett glykaemiás kontrollon túl újabban a glykaemiás variabilitás és egyes antidiabetikumok idegi funkciókra gyakorolt pleiotrop hatásai kerültek előtérbe. A testsúlycsökkentés nemcsak a diabetes, de az autonóm neuropathia tekintetében is jótékony hatású, ugyanakkor az életmód-terápia további összetevőivel kapcsolatban nem egyértelműek az adatok. Orv Hetil. 2024; 165(16): 602–612.

Autonomic dysfunction and treatment strategies in intracerebral hemorrhage

AIMS

Autonomic dysfunction with central autonomic network (CAN) damage occurs frequently after intracerebral hemorrhage (ICH) and contributes to a series of adverse outcomes. This review aims to provide insight and convenience for future clinical practice and research on autonomic dysfunction in ICH patients.

DISCUSSION

We summarize the autonomic dysfunction in ICH from the aspects of potential mechanisms, clinical significance, assessment, and treatment strategies. The CAN structures mainly include insular cortex, anterior cingulate cortex, amygdala, hypothalamus, nucleus of the solitary tract, ventrolateral medulla, dorsal motor nucleus of the vagus, nucleus ambiguus, parabrachial nucleus, and periaqueductal gray. Autonomic dysfunction after ICH is closely associated with neurological functional outcomes, cardiac complications, blood pressure fluctuation, immunosuppression and infection, thermoregulatory dysfunction, hyperglycemia, digestive dysfunction, and urogenital disturbances. Heart rate variability, baroreflex sensitivity, skin sympathetic nerve activity, sympathetic skin response, and plasma catecholamine concentration can be used to assess the autonomic functional activities after ICH. Risk stratification of patients according to autonomic functional activities, and development of intervention approaches based on the restoration of sympathetic-parasympathetic balance, would potentially improve clinical outcomes in ICH patients.

CONCLUSION

The review systematically summarizes the evidence of autonomic dysfunction and its association with clinical outcomes in ICH patients, proposing that targeting autonomic dysfunction could be potentially investigated to improve the clinical outcomes.

Unveiling autonomic failure in synucleinopathies: Significance in diagnosis and treatment

Autonomic failure is frequently encountered in synucleinopathies such as multiple system atrophy (MSA), Parkinson's disease (PD), Lewy body disease, and pure autonomic failure (PAF). Cardiovascular autonomic failure affects quality of life and can be life threatening due to the risk of falls and the increased incidence of myocardial infarction, stroke, and heart failure. In PD and PAF, pathogenic involvement is mainly post-ganglionic, while in MSA, the involvement is mainly pre-ganglionic. Cardiovascular tests exploring the autonomic nervous system (ANS) are based on the analysis of continuous, non-invasive recordings of heart rate and digital blood pressure (BP). They assess facets of sympathetic and parasympathetic activities and provide indications on the integrity of the baroreflex arc. The tilt test is widely used in clinical practice. It can be combined with catecholamine level measurement and analysis of baroreflex activity and cardiac variability for a detailed analysis of cardiovascular damage. MIBG myocardial scintigraphy is the most sensitive test for early detection of autonomic dysfunction. It provides a useful measure of post-ganglionic sympathetic fiber integrity and function and is therefore an effective tool for distinguishing PD from other parkinsonian syndromes such as MSA. Autonomic cardiovascular investigations differentiate between certain parkinsonian syndromes that would otherwise be difficult to segregate, particularly in the early stages of the disease. Exploring autonomic failure by gathering information about residual sympathetic tone, low plasma norepinephrine levels, and supine hypertension can guide therapeutic management of orthostatic hypotension (OH).

Non-Pharmacological Treatment of Autonomic Dysfunction in Parkinson's Disease and Other Synucleinopathies

Symptoms of autonomic dysfunction are prevalent and can be very debilitating, reducing the quality of life in patients with Parkinson's disease (PD) and other synucleinopathies such as dementia with Lewy bodies and multiple system atrophy. Non-pharmacological therapies are key to effective management and are frequently used alone in patients with mild autonomic symptoms, or in combination with pharmacological therapies in patients with moderate and severe symptoms. This article focuses on non-pharmacological approaches. Our objective was to review the non-drug and non-surgical approaches to treating autonomic symptoms in patients with PD and other synucleinopathies, focusing on cardiovascular, gastrointestinal, and genitourinary autonomic dysfunction. Evidence supporting the effectiveness of non-pharmacological treatment for the management of neurogenic orthostatic hypotension, supine hypertension, constipation, and bladder and sexual dysfunction is available. High-quality prospective trials are scarce, yet some non-pharmacological interventions (e.g., physical counter maneuvers) can be evaluated relatively quickly on an individual basis and often seem effective. The emerging variety of clinical presentations advocates for a stepwise, individualized, and non-pharmacological approach for the management of autonomic symptoms. Often, the first step is to reduce or discontinue drugs that cause or aggravate autonomic symptoms followed by lifestyle measures. While non-pharmacological and non-surgical treatments are available and, in many cases, effective to improve symptoms of autonomic dysfunction in PD and other synucleinopathies, they are often overlooked. Large randomized trials testing and comparing non-pharmacological approaches are warranted.

Non-pharmacological and drug treatment of autonomic dysfunction in multiple system atrophy: current status and future directions

Multiple system atrophy (MSA) is a sporadic, fatal, and rapidly progressive neurodegenerative disease of unknown etiology that is clinically characterized by autonomic failure, parkinsonism, cerebellar ataxia, and pyramidal signs in any combination. Early onset and extensive autonomic dysfunction, including cardiovascular dysfunction characterized by orthostatic hypotension (OH) and supine hypertension, urinary dysfunction characterized by overactive bladder and incomplete bladder emptying, sexual dysfunction characterized by sexual desire deficiency and erectile dysfunction, and gastrointestinal dysfunction characterized by delayed gastric emptying and constipation, are the main features of MSA. Autonomic dysfunction greatly reduces quality of life and increases mortality. Therefore, early diagnosis and intervention are urgently needed to benefit MSA patients. In this review, we aim to discuss the systematic treatment of autonomic dysfunction in MSA, and focus on the current methods, starting from non-pharmacological methods, such as patient education, psychotherapy, diet change, surgery, and neuromodulation, to various drug treatments targeting autonomic nerve and its projection fibers. In addition, we also draw attention to the interactions among various treatments, and introduce novel methods proposed in recent years, such as gene therapy, stem cell therapy, and neural prosthesis implantation. Furthermore, we elaborate on the specific targets and mechanisms of action of various drugs. We would like to call for large-scale research to determine the efficacy of these methods in the future. Finally, we point out that studies on the pathogenesis of MSA and pathophysiological mechanisms of various autonomic dysfunction would also contribute to the development of new promising treatments and concepts.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD): a collaborative review of the current understanding

PURPOSE

To provide an overview of the discovery, presentation, and management of Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD). To discuss a search for causative etiology spanning multiple disciplines and continents.

METHODS

The literature (1965-2022) on the diagnosis, management, pathophysiology, and potential etiology of ROHHAD was methodically reviewed. The experience of several academic centers with expertise in ROHHAD is presented, along with a detailed discussion of scientific discovery in the search for a cause.

RESULTS

ROHHAD is an ultra-rare syndrome with fewer than 200 known cases. Although variations occur, the acronym ROHHAD is intended to alert physicians to the usual sequence or unfolding of the phenotypic presentation, including the full phenotype. Nearly 60 years after its first description, more is known about the pathophysiology of ROHHAD, but the etiology remains enigmatic. The search for a genetic mutation common to patients with ROHHAD has not, to date, demonstrated a disease-defining gene. Similarly, a search for the autoimmune basis of ROHHAD has not resulted in a definitive answer. This review summarizes current knowledge and potential future directions.

CONCLUSION

ROHHAD is a poorly understood, complex, and potentially devastating disorder. The search for its cause intertwines with the search for causes of obesity and autonomic dysregulation. The care for the patient with ROHHAD necessitates collaborative international efforts to advance our knowledge and, thereby, treatment, to decrease the disease burden and eventually to stop, and/or reverse the unfolding of the phenotype.

[Over 5 years follow-up of three cases of autoimmune autonomic ganglionopathy]

We report the clinical course of three cases of anti-ganglionic acetylcholine receptor (gAChR) antibody positive auto-immune autonomic ganglionopathy (AAG) that have been followed for over 5 years. In all three cases, the symptoms improved by acute treatment, but ultimately relapsed. The first case was a female in her 20s who had a chronic history of photophobia, constipation and amenorrhea. The symptoms almost disappeared by plasma exchange, and menstruation resumed. During the course, it relapsed once after a cold. There was no recurrence of AAG during the two pregnancies. The second case was a male in his 60s who visited a hospital for the acute onset of orthostatic hypotension (OH) and psychological symptoms (infantilization and psychogenic pseudosyncope). Although IVIg was effective, it recurred frequently and was difficult to treat. However, all the symptoms disappeared eight years after the onset without any particular reasons. The third case was a female in her 80s who had a chronic history of OH. Acute treatment was effective, but AAG recurred repeatedly. Additionally, it was difficult to judge relapse because of the residual sequelae. During the course, cerebral hemorrhage due to supine hypertension or short-time blood pressure variability and femoral neck fracture caused by OH occurred. She eventually became a wheelchair. This report is clinically important because there are few reports of long-term follow-up of AAG.

Understanding and Managing Autonomic Disorders in the Neurocritical Care Unit: A Comprehensive review

BACKGROUND

For a favorable outcome, patients admitted to critical care units require continuous monitoring and swift decision-making ability regarding management. One of the biggest challenges in neurocritical care units is the identification and management of autonomic dysfunction and in the worst-case scenario, autonomic storms.

OBJECTIVE

Most of the literature available focuses mainly on autonomic storms following traumatic brain injury. However, due to the myriad neurological presentations in a critical care setting, it is particularly important for physicians and intensivists to suspect and manage autonomic dysfunction in various neurological scenarios.

METHODS

Understanding the mechanism of paroxysmal sympathetic hyperactivity (PSH) is essential for early recognition and treatment. PSH-AM is an assessment measurement scale to diagnose and assess the severity of PSH in traumatic brain injury. However, this is not yet standardized across all neurological settings.

CONCLUSION

We present a comprehensive report on understanding the mechanism of autonomic storms across various neurological disorders and outline the management.

Diabetic Gastroenteropathy: Soothe the Symptoms or Unravel a Cure?

Autonomic neuropathy in patients with diabetes mellitus, and especially complications related to gastrointestinal neuropathy, are often overlooked in the clinic. Diabetic gastroenteropathy affects every segment of the gastrointestinal tract and generates symptoms that may include nausea, early satiety, vomiting, abdominal pain, constipation, and diarrhea. Severe cases can be complicated by weight loss, dehydration, and electrolyte disturbances. The pathophysiology is complex, the diagnostics and treatment options are multidisciplinary, and there is generally a lack of evidence for the treatment options. The aims for this review are first to summarize the pathophysiology and describe possible and expected symptoms and complications.Further, we will try to supply the clinician with a straightforward tool for diagnostics, and then, we shall summarize established treatment options, including diet recommendations, pharmacological and non-pharmacological options. Finally, we will explore the multiple possibilities of novel treatment, looking at medications related to the pathophysiology of neuropathy, other manifestations of autonomic neuropathies, and symptomatic treatment for other gastrointestinal disorders, also including new knowledge of endosurgical and neuromodulatory treatment. The overall goal is to increase awareness and knowledge on this frequent diabetic complication and to provide better tools for diagnosis and treatment. Ultimately, we hope to encourage further research in this field, as there are clear shortcomings in terms of biomarkers, pathophysiology, as well as treatment possibilities. In conclusion, diagnosis and management of diabetic gastroenteropathy are challenging and often require multidisciplinary teams and multimodal therapies. Treatment options are sparse, but new pharmacological, endoscopic, and neuromodulatory techniques have shown promising results in initial studies.

Cardiac failure in a child with tuberculous meningitis as a complication of Paroxysmal sympathetic hyperactivity

BACKGROUND

Paroxysmal sympathetic hyperactivity (PSH) is a disorder due to the loss of regulation of autonomic activity. The most common condition predisposing to the development of PSH is traumatic brain injury (TBI), followed by anoxic brain injury, stroke, tumors, and infections. Awareness about the condition and early recognition is important to avoid life threatening complications.

CASE

We report a 4-year-old child with tuberculous meningitis with symptoms of PSH who developed cardiac failure. PSH episodes were treated with beta blocker, benzodiazepine, morphine, dexmedetomidine, baclofen, and tizanidine. Three weeks after readmission PSH episodes decreased and the patient was transferred to the general ward.

CONCLUSIONS

PSH assessment tool has benefits such as monitoring the patient, evaluating response to treatment and early diagnosing PSH patients.

Updates on the Diagnosis and Treatment of Peripheral Autonomic Neuropathies

PURPOSE OF REVIEW

Autonomic neuropathies are a complex group of disorders and result in diverse clinical manifestations that affect the cardiovascular, gastrointestinal, urogenital, and sudomotor systems. We focus this review on the diagnosis and treatment of peripheral autonomic neuropathies. We summarize the diagnostic tools and current treatment options that will help the clinician care for individuals with peripheral autonomic neuropathies.

RECENT FINDINGS

Autonomic neuropathies occur often in conjunction with somatic neuropathies but they can also occur in isolation. The autonomic reflex screen is a validated tool to assess sympathetic postganglionic sudomotor, cardiovascular sympathetic noradrenergic, and cardiac parasympathetic (i.e., cardiovagal) function. Initial laboratory evaluation for autonomic neuropathies includes fasting glucose or oral glucose tolerance test, thyroid function tests, kidney function tests, vitamin-B12, serum, and urine protein electrophoresis with immunofixation. Other laboratory tests should be guided by the clinical context. Reduced intraepidermal nerve density on skin biopsy is a finding, not a diagnosis. Skin biopsy can be helpful in selected individuals for the diagnosis of disorders affecting small nerve fibers; however, we strongly discourage the use of skin biopsy without clinical-physiological correlation. Ambulatory blood pressure monitoring may lead to early identification of patients with cardiovascular autonomic neuropathy in the primary care setting. Disease-modifying therapies should be used when available in combination with nonpharmacological management and symptomatic pharmacologic therapies. Autonomic function testing can guide the therapeutic decisions and document improvement with treatment. A systematic approach guided by the autonomic history and standardized autonomic function testing may help clinicians when identifying and/or counseling patients with autonomic neuropathies. Treatment should be individualized and disease-modifying therapies should be used when available.

[Paroxysmal sympathetic hyperactivity]

Paroxysmal sympathetic hyperactivity (PSH) is a condition mainly described in patients after traumatic brain injury and it is also known under the terms "autonomic storm" and "dysautonomia". It affects between 8-10% of patients after traumatic brain injury and can also affect patients after other neurological diseases, such as anoxic brain injury, stroke, tumors or infections. PSH manifests with six main symptoms: tachycardia, tachypnea, hypertension, hyperthermia, hyperhidrosis and increased muscle tonus. It is of outmost importance to exclude other causes for the symptoms and there are diagnostic criteria established to identify and diagnose PSH. The treatment is pharmacological and non-pharmacological and often multimodal. PSH is probably underdiagnosed and increased awareness is needed.

Do manual therapies have a specific autonomic effect? An overview of systematic reviews

Background

The impact of manual therapy interventions on the autonomic nervous system have been largely assessed, but with heterogeneous findings regarding the direction of these effects. We conducted an overview of systematic reviews to describe if there is a specific autonomic effect elicited by manual therapy interventions, its relation with the type of technique used and the body region where the intervention was applied.

Methods

We conducted an overview according to a publicly registered protocol. We searched the Cochrane Database of Systematic Reviews, MEDLINE, EPISTEMONIKOS and SCOPUS, from their inception to march 2021. We included systematic reviews for which the primary aim of the intervention was to assess the autonomic effect elicited by a manual therapy intervention in either healthy or symptomatic individuals. Two authors independently applied the selection criteria, assessed risk of bias from the included reviews and extracted data. An established model of generalisation guided the data analysis and interpretation.

Results

We included 12 reviews (5 rated as low risk of bias according the ROBIS tool). The findings showed that manual therapies may have an effect on both sympathetic and parasympathetic systems. However, the results from included reviews were inconsistent due to differences in their methodological rigour and how the effects were measured. The reviews with a lower risk of bias could not discriminate the effects depending on the body region to which the technique was applied.

Conclusion

The magnitude of the specific autonomic effect elicited by manual therapies and its clinical relevance is uncertain. We point out some specific recommendations in order to improve the quality and relevance of future research in this field.

Paroxysmal Sympathetic Hyperactivity in Severe Anti-N-Methyl-d-Aspartate Receptor Encephalitis: A Single Center Retrospective Observational Study

Background

Paroxysmal sympathetic hyperactivity (PSH) is a disorder with excessive sympathetic activity commonly recognized in patients with acquired brain injury. Autonomic instability is frequent in anti-N-methyl-d-aspartate receptor encephalitis (anti-NMDARE). However, PSH in anti-NMDARE has gained little attention.

Methods

We retrospectively reviewed 24 patients diagnosed with severe anti-NMDARE in the neuro-intensive care unit (NICU) between 2014 and 2019. Patients were assessed with the PSH assessment measure (PSH-AM) scale, and categorized into "PSH+" group and "PSH-" group. The clinical characteristics, hospital mortality, and functional outcome by modified Rankin Scale (mRS) score at six months after discharge were compared between the two groups. Among patients with PSH+, the clinical features and pharmacotherapy of PSH were summarized and compared.

Results

Twenty-four patients were included in the study. Twelve of them (50%) were categorized as PSH+ based on PSH-AM scores. There were no significant differences in the demographic characteristic, GCS scores upon admission, incidence of status epilepticus, teratoma occurrence, hospital mortality, and 6-month mRS between PSH+ and PSH- groups. Patients with PSH+ had increased length of NICU stay, hospital stay and duration of mechanical ventilation. The most prominent clinical features of PSH in severe anti-NMDARE were tachycardia and hyperthermia, while posturing was the relatively mildest clinical feature. Propranolol and clonazepam were more commonly used than gabapentin in pharmacotherapy of PSH in severe anti-NMDARE.

Conclusions

The incidence of PSH in severe anti-NMDARE patients was as high as 50%. Patients with PSH demonstrated prolonged NICU stay, hospital stay and increased duration of mechanical ventilation, while no effect on hospital mortality and functional outcome. Clinicians should be aware of the distinctive characteristics and treatment options of PSH in severe anti-NMDARE.

Cardiovascular and sudomotor dysfunction in Hirayama disease

Hirayama disease is a disease of young males causing atrophy of small muscles of the affected hand and forearm. Localized autonomic dysfunction of the affected upper limb such as cold skin and excessive sweating has been described in some patients. In this study, we looked for local as well as systemic involvement of autonomic nervous system in patients with Hirayama disease. Forty-four patients with a median duration of illness of 3 years were included in the study. Assessment of symptom profile and evaluation of autonomic nervous system were done at the time of enrolment. The mean age at presentation was 21.9 (10-32) years, with a delay in seeking medical attention of around 3 (1-11) years. Localized clinical autonomic dysfunction was present in 39 (88.6%) patients, while objective generalized autonomic dysfunction was present in 33 (75%) patients. Cold skin and excessive sweating showed good correlation with the presence of objective autonomic dysfunction (P < 0.05). In three patients, sympathetic skin response (SSR) could not be recorded in one of the four limbs. Compared to controls, the SSR results in patients with Hirayama disease showed increased latency (1.64 ± 0.21 vs. 1.57 ± 0.14, P 0.04) and decreased amplitude in upper limbs (0.65 ± 0.19 vs. 0.86 ± 0.40, P 0.01). Hirayama disease has both localized and systemic dysautonomia. Careful longitudinal evaluation during the progressive phase of the disease may help in diagnosing subtle systemic autonomic dysfunction.

Autonomic Dysfunction in Parkinson's Disease

Recognition of the importance of nonmotor dysfunction as a component of Parkinson's disease has exploded over the past three decades. Autonomic dysfunction is a frequent and particularly important nonmotor feature because of the broad clinical spectrum it covers. Cardiovascular, gastrointestinal, urinary, sexual, and thermoregulatory abnormalities all can appear in the setting of Parkinson's disease. Cardiovascular dysfunction is characterized most prominently by orthostatic hypotension. Gastrointestinal dysfunction can involve virtually all levels of the gastrointestinal tract. Urinary dysfunction can entail either too frequent voiding or difficulty voiding. Sexual dysfunction is frequent and frustrating for both patient and partner. Alterations in sweating and body temperature are not widely recognized but often are present. Autonomic dysfunction can significantly and deleteriously impact quality of life for individuals with Parkinson's disease. Because effective treatment for many aspects of autonomic dysfunction is available, it is vitally important that assessment of autonomic dysfunction be a regular component of the neurologic history and exam and that appropriate treatment be initiated and maintained.

Effectiveness of an osteopathic treatment on the autonomic nervous system: a systematic review of the literature

OBJECTIVE

The objective of this systematic review was to evaluate the effectiveness of an osteopathic treatment on the autonomic nervous system (ANS). For this purpose, published primary studies were analysed and critically evaluated.

METHOD

To generate this review, 15 electronic databases were systematically searched for studies. Randomized clinical controlled trials (RCT) and clinical controlled trials (CCT) are included in the review and evaluated with appropriate assessment tools (Downs and Black Checklist and the checklist from Kienle and Kiene).

RESULTS

23 published studies (10 RCT, 1 clinic multi-centre study, 1 CCT, 5 randomized cross-over studies, 5 randomized pilot studies and 1 single case study) are included in this review. The studies were evaluated with the assessment tools according to their quality. 3 studies are graded as high quality, 11 as moderate and 8 as low-quality studies.

CONCLUSION

The included published studies represent a good level of evidence. Due to a small number of subjects and no follow-ups, the methodological quality is rated as moderate. A significant change on the ANS was shown in studies including High-Velocity Low-Amplitude Techniques (HVLAT). No statement could be drawn in studies in which they used cranial osteopathic techniques due to the lack of methodological quality. A significant change on the ANS is shown in the treatment of the suboccipital region. In studies which evaluated the effectiveness of mobilization in the cervical and thoracic region, no statement could be displayed due to a low level of evidence. None of the findings in these studies have given statements if ANS activation takes place in the sympathetic or parasympathetic system.

Obstructive sleep apnea syndrome and autonomic dysfunction

Autonomic nervous system (ANS) has been extensively explored in obstructive sleep apnea (OSA). Autonomic alterations in these patients have been described by means of several methods, evaluating ANS function both directly with microneurography and indirectly through baroreflex sensitivity (BRS, by the sequence method or the cross-spectral approach), heart rate variability analysis (HRV, both in the time and frequency domain) during sleep and wake, or conventional laboratory tests, including cold pressor test, hand grip test or measurement of urinary cathecolamine excretion. Several studies in OSA patients have shown ANS alterations, in particular sympathetic overactivity, both acutely during apnea events and chronically during the daytime, being both also involved in cardiovascular consequences of sleep disordered breathing. The association between OSA and sympathetic dysregulation suggests a dose response relationship between OSA severity and the degree of sympathetic overactivity and this association seems to be reversible as the treatment of OSA is implemented. Additionally ANS is involved in regulating visceral and humoral functions to maintain the body homeostasis and in reaction and adaptation to external and internal stressor stimuli. However, the vast majority of studies have focussed on cardiovascular alterations, which are easier to measure, somewhat neglecting the other functions regulated by ANS. More evidence is therefore needed to better characterize the impact that sleep disorder breathing may have on ANS both in the short and long term.

Update on the Impact, Diagnosis and Management of Cardiovascular Autonomic Neuropathy in Diabetes: What Is Defined, What Is New, and What Is Unmet

The burden of diabetic cardiovascular autonomic neuropathy (CAN) is expected to increase due to the diabetes epidemic and its early and widespread appearance. CAN has a definite prognostic role for mortality and cardiovascular morbidity. Putative mechanisms for this are tachycardia, QT interval prolongation, orthostatic hypotension, reverse dipping, and impaired heart rate variability, while emerging mechanisms like inflammation support the pervasiveness of autonomic dysfunction. Efforts to overcome CAN under-diagnosis are on the table: by promoting screening for symptoms and signs; by simplifying cardiovascular reflex tests; and by selecting the candidates for screening. CAN assessment allows for treatment of its manifestations, cardiovascular risk stratification, and tailoring therapeutic targets. Risk factors for CAN are mainly glycaemic control in type 1 diabetes mellitus (T1DM) and, in addition, hypertension, dyslipidaemia, and obesity in type 2 diabetes mellitus (T2DM), while preliminary data regard glycaemic variability, vitamin B12 and D changes, oxidative stress, inflammation, and genetic biomarkers. Glycaemic control prevents CAN in T1DM, whereas multifactorial intervention might be effective in T2DM. Lifestyle intervention improves autonomic function mostly in pre-diabetes. While there is no conclusive evidence for a disease-modifying therapy, treatment of CAN manifestations is available. The modulation of autonomic function by SGLT2i represents a promising research field with possible clinical relevance.

Autonomic dysfunction: Diagnosis and management

The autonomic nervous system is designed to maintain physiologic homeostasis. Its widespread connections make it vulnerable to disruption by many disease processes including primary etiologies such as Parkinson's disease, multiple system atrophy, dementia with Lewy bodies, and pure autonomic failure and secondary etiologies such as diabetes mellitus, amyloidosis, and immune-mediated illnesses. The result is numerous symptoms involving the cardiovascular, gastrointestinal, and urogenital systems. Patients with autonomic dysfunction (AUD) often have peripheral and/or cardiac denervation leading to impairment of the baroreflex, which is known to play a major role in determining hemodynamic outcome during orthostatic stress and low cardiac output states. Heart rate and plasma norepinephrine responses to orthostatic stress are helpful in diagnosing impairment of the baroreflex in patients with orthostatic hypotension (OH) and suspected AUD. Similarly, cardiac sympathetic denervation diagnosed with MIBG scintigraphy or ¹⁸F-DA PET scanning has also been shown to be helpful in distinguishing preganglionic from postganglionic involvement and in diagnosing early stages of neurodegenerative diseases. In this chapter, we review the causes of AUD, the pathophysiology and resulting cardiovascular manifestations with emphasis on the diagnosis and treatment of OH.

ELECTROLYTE CONTENT IN SALIVA OF CHILDREN WITH DEVIATION IN VEGETATIVE STATUS RESIDING AT RADIOACTIVELY CONTAMINATED TERRITORIES OF UKRAINE AFTER APPLICATION OF INTERMITTENT NORMOBARIC HYPOXIA

Objective was to determine the content of sodium (Na+), potassium (K+), calcium (Ca2+), and magnesium (Mg2+) elec-trolytes in non-stimulated mixed saliva of children, with disorders of autonomous nervous system (ANS), who wereborn and are permanently residing at radioactive contaminated territories after application of intermittent normo-baric hypoxia (INH) of sanogenic level.Patientes and methods. The children (41 boys and 62 girls) aged 6-17 years were examined. All they were dividedinto three groups: the control group consisted of 30 persons (group I); the comparison group - 30 person (groupII); the main group - 43 patients (group III). The collection of anamnesis, patient complaints, clinical and labora-tory examinations were included into the studied program. The content of electrolytes in oral fluids was determinedby the atomic absorption method. 10 seances of INH with a hypoxic component of 12 % oxygen in nitrogen wereused by us.Results. It was shown that the content of electrolytes in non-stimulated mixed saliva had a multidirectional signi-ficance in different age groups after INH: in examined children of primary school age (6-11 years), the Na+ concen-tration was significantly increased by 0.8 mmol/l, K+ concentration was decreased by 3 mmol/l, Ca2+ concentrationwas decreased by 1.07 mmol/l and in children of senior school age (12-17 years) - Na+, and Ca2+ concentrations weredecreased by 2 mmol/l and 0.17 mmol/l, respectively.Сonclusions. The obtained results allow to recommend the INH seances for addition to basic treatment of childrenwith disorders of autonomous nervous system, who were born and are permanently residing at radioactive contam-inated territories of Ukraine.

Cardiac Autonomic Neuropathy in Diabetes Mellitus

Cardiovascular autonomic neuropathy (CAN) is a severely debilitating yet underdiagnosed condition in patients with diabetes. The prevalence can range from 2.5% (based on the primary prevention cohort in the Diabetes Control and Complications Trial) to as high as 90% of patients with type 1 diabetes. Clinical manifestations range from orthostasis to myocardial infarction. The diagnosis is made using multiple autonomic function tests to assess both sympathetic and parasympathetic function. The pathophysiology of CAN is complex, likely multifactorial, and not completely understood. Treatment is limited to symptomatic control of orthostatic hypotension, which is a late complication, and current strategies to reverse CAN are limited. This review explores the epidemiology, pathophysiology, clinical manifestations, diagnosis, and complications of CAN as well as current treatment options.