Week 06 - CMS200 - Non-organic Fatigue

Fatigue CMS200 Week 6 Learning Outcomes Understand and define Fatigue and Systemic Intolerance Disease (Chronic Fatigue Syndrome), their symptoms, and common synonyms Recognize the prevalence, etiology, risk factors, and impact of fatigue on patients’ lives, including differences in gende...

Fatigue CMS200 Week 6 Learning Outcomes Understand and define Fatigue and Systemic Intolerance Disease (Chronic Fatigue Syndrome), their symptoms, and common synonyms Recognize the prevalence, etiology, risk factors, and impact of fatigue on patients’ lives, including differences in gender and age Identify the major components of clinically relevant fatigue and differentiate between acute and chronic fatigue Learn to conduct a detailed history and physical examination to assess fatigue, including psychosocial and sleep history, and identify common causes and “must not miss” diagnoses (e.g., anemia, hypothyroidism, diabetes mellitus) Learning Outcomes Understand the organ/system approach to constructing a differential diagnosis for fatigue and rank the differential diagnosis based on patient’s history and physical examination findings Learn about the common causes of fatigue, including medical conditions, psychiatric disorders, sleep disorders, medications, and lifestyle factors Understand the importance of laboratory tests, electrodiagnostic testing, and polysomnogram in evaluating fatigue and interpreting the results to recommend appropriate interventions Learning Outcomes Recognize the importance of a supportive environment and acknowledgement of suffering in managing chronic fatigue conditions Understand the role of follow-up visits and medication adjustments in the long-term management of fatigue Know when to refer or monitor patients with fatigue and Systemic Intolerance Disease (Chronic Fatigue Syndrome) A patient walks through your door… KG, a 43-year-old woman, comes to your clinic with a concern of fatigue that has been going on “for months”. She ignored it initially since she has a lot of responsibilities at home and work, and has always ”powered through”; but, the fatigue has gotten worse and is now impacting her day-to-day function. It is a struggle to keep up with the kids’ school and extracurricular schedules, and making dinner at the end of a long work day “feels impossible”. She is finding it difficult to concentrate on tasks at work, and her memory is “not as sharp” as before. She wonders if this is “just life”, as a working mom with two young children at home, or if there is something else going on with her health that is the cause. A patient walks through your door… What questions do you want to ask? Are there any alarm symptoms to assess? Which physical exams do you consider? Is there any lab testing that can help determine a diagnosis? Do you need to refer for co-management? Fatigue What is “Fatigue”? “A state of physical or mental exhaustion with difficulty or inability to initiate or maintain activity. It can compromise on a person’s mental alertness, physical motor skills, judgement and decision-making.” (Ho and Zheng, 2022) Fatigue is common, usually short-lived, and often related to some identified cause (Kerr, 2018) Fatigue can impact an individual’s work performance, and family and social relationships Fatigue: Epidemiology Fatigue is one of the most common symptoms encountered in primary care settings 1 in 5 family medicine patients present with fatigue (Rosenthal, 2008) According to international surveys, fatigue is the main reason in 6.5% and a secondary reason in 19% of patients (Ho and Zheng, 2022) 1 in 3 adolescents report fatigue at least four days per week Sex differences in describing fatigue: Men typically say they feel “tired” Women say they feel “depressed” or “anxious” Fatigue: Epidemiology Lifetime prevalence of significant fatigue (present for ≥ 2 weeks) is approximately 25% (Nadler, 2023) Common causes: overexertion, deconditioning, viral illness, upper respiratory tract infection, anemia, lung disease, medications, cancer, depression, and surgery (Rosenthal, 2008) 6-12 weeks of fatigue is not unusual during recovery from even minor surgery Fatigue: Epidemiology Fatigue of unknown cause (idiopathic fatigue) or related to psychiatric illness is a greater proportion of cases compared to fatigue due to physical illness, injury, alcohol, or medications No etiology can be identified in 1/3 of cases (Nadler, 2023) Up to 75% of patients with fatigue have psychiatric symptoms (Weinstein, 2023) Sleep disorders, especially Obstructive Sleep Apnea and insomnia syndromes, are common in patients with fatigue (Weinstein, 2023) Fatigue in older adults increases the risk of developing negative health outcomes (mortality OR, 2.14), disabilities in basic activities of daily living (OR, 3.22), or the occurrence of physical decline (OR, 1.42) (Nadler, 2023) Fatigue: Classification by Time Frame Acute fatigue: lasts ≤ 1 month and is relieved with rest Subacute fatigue: lasts between 1 to 6 months Chronic fatigue: lasts ≥ 6 months and is not relieved with rest Fatigue: Classification by Etiology Secondary fatigue: due to an underlying medical condition; may last ≥ 1 month but generally lasts < 6 months Physiologic fatigue: caused by a lifestyle imbalance in routines of sleep, exercise, diet, or other activity not attributed to an underlying medical condition; and is alleviated with rest Fatigue: Diagnostic Criteria Clinically relevant fatigue is composed of three major components: 1. Generalized weakness (difficulty in initiating activities) 2. Easy fatigability (difficulty in completing activities) 3. Mental fatigue (difficulty with concentration and memory) Differentiating between Sleepiness and Fatigue Sleepiness Fatigue Temporarily aroused by activity, Intensified by activity at least in the short-term Feel better after a nap Report lack of energy, mental exhaustion, poor muscle endurance, delayed recovery after physical exertion, nonrestorative sleep Evaluating Sleep Quality and Quantity What time do you go to bed? What time do you fall asleep? After you lie down, how long does it take you to fall asleep? Do you leave the TV or radio on as you are attempting to fall asleep? After falling asleep, what time do you first wake up? What awakens you? How often do you use the bathroom at night? Do you have pain at night? Evaluating Sleep Quality and Quantity How long does it take you to return to sleep after waking up? What time do you get out of bed in the morning? Do you feel rested in the morning? Do you nap during the day? What medications do you take? Do you drink alcohol or use other drugs? Do you exercise? What time of day? Epworth Sleepiness Scale (ESS) 0 = would never dose 2 = moderate chance of dozing 1 = slight chance of dozing 3 = high chance of dozing How likely are you to doze off or fall asleep in the following situations, in contrast to just feeling tired? Chance of dozing Even if you haven’t done some of these activities (0-3) recently, think about how they would have affected you. Sitting and reading 0 1 2 3 Watching television 0 1 2 3 Siting inactive in a public place (e.g., theater, meeting) 0 1 2 3 As a passenger in a car for an hour without a break 0 1 2 3 Lying down to rest in the afternoon 0 1 2 3 excessive A total score of less than 10 suggests that you may not be suffering from daytime sleepiness. Sitting and talking to someone 0 1 2 A total score of 10 or more suggests that you may need further evaluation 3 to determine the cause of your excessive daytime sleepiness and whether you have an underlying  Fatigue Severity Scale (FSS) During the past week, I have found that: Disagree Agree 1. My motivation is lower when I am fatigued. 0 1 2 3 4 5 6 7 2. Exercise brings on my fatigue. 0 1 2 3 4 5 6 7 3. I am easily fatigued. 0 1 2 3 4 5 6 7 4. Fatigue interferes with my physical functioning. 0 1 2 3 4 5 6 7 5. Fatigue causes frequent problems for me. 0 1 2 3 4 5 6 7 6. My fatigue prevents sustained physical functioning. 0 1 2 3 4 5 A total score of less than 36 suggests that you may not be suffering from 6 fatigue. 7 A total score of 36 or more suggests that you may need further evaluation by a physician. 7. Fatigue interferes with carrying out certain duties and 0 1 2 3 4 5 responsibilities 6 7 Chronic Fatigue Chronic Fatigue: Epidemiology Fatigue that lasts longer than 6 months The prevalence of idiopathic chronic fatigue ranges: 5 – 40 per 100,000 depending on the population studied (Rosenthal, 2008) Chronic fatigue occurs in all age groups, including children Women, minority groups, and the socioeconomically disadvantaged have a higher prevalence of chronic fatigue (Kerr, 2018) Chronic Fatigue: Epidemiology Two-thirds of patients with chronic fatigue do not meet the criteria for “Chronic Fatigue Syndrome” – but share many similarities and have only a slightly better prognosis 64% of patients have limited improvement Only 2% of patients report complete long-term resolution of symptoms Patients whose symptoms worsen for longer than 24 hours after physical exertion have a poor prognosis (Rosenthal, 2008) Chronic Fatigue: Causes In approximately 70% of patients with chronic fatigue, a medical or psychological explanation can be determined (Simons, 2012) Psychiatric disorders (depression or anxiety) are the predominant causes Approximately 25% of patients have an acute or chronic medical condition that is the cause of their fatigue Chronic Fatigue: Causes Some studies suggest that social or personal factors may be important causes of fatigue (Simons) E.g., home and outside work, poor sleep, interpersonal problems, caregivers to ill family members, financial worries Other studies point to social, geographic, environmental, and genetic factors are contributors to the development of fatigue and depression Referral and Management Identify and treat the underlying condition that is contributing to the fatigue If possible, adjust medications (replace or discontinue) that may be causing fatigue Schedule regular follow-up visits (rather than sporadic urgent appointments) for effective long-term management Referral for co-management, as needed Systemic Intolerance Disease “Chronic Fatigue Syndrome” Systemic Intolerance Disease: Epidemiology aka Systemic Exertion Intolerance Disease (SEID), Chronic Fatigue Syndrome (CFS), Myalgic Encephalomyelitis (ME) Several studies have shown that the term “Chronic Fatigue Syndrome” affects patients’ perceptions of their illness, can diminish its seriousness, and promote a misunderstanding of the condition “Myalgic Encephalomyelitis” is also misleading because of the lack of evidence for brain inflammation, and myalgia is not a core symptom of the disease “Systemic Exertion Intolerance Disease” captures the main characteristic that multiple organ systems are impacted by exertion of any kind (physical, cognitive, emotional) and associated with autonomic, neuroendocrine, and immune dysfunction Systemic Intolerance Disease: Epidemiology A complex syndrome of uncertain etiology, causing profound unexplained fatigue No physical finding or lab test can be used to confirm the diagnosis Studies have given different prevalence rates based on the type of definition used, the type of population surveyed, and the study design used (Sapra and Bhandari, 2023) Systemic Intolerance Disease: Epidemiology Estimated to affect 17 to 24 million people worldwide – approximately 1% of the population (Ho and Zheng, 2022) Approximately 836,000 to 2.5 million individuals in the U.S. In 2014, about 1.4% of the adult Canadian population reported having “chronic fatigue syndrome” (Statistics Canada, 2015) Systemic Intolerance Disease: Epidemiology Higher rate in women (1.5 to 2x) verses men As per a study in 2004, it was estimated that approximately 2.2 million American adults (about 1,197 people per 100,000) suffer from SEID and SEID-like illnesses (National Academy of Sciences, 2015) Systemic Intolerance Disease: Epidemiology Prevalence is significantly higher between 40 – 70 years of age Average age of onset is 33 Has been reported in patients < age 10 and > age 70 Most patients currently diagnosed in the White population (Sapra and Bhandari, 2023) – though some studies suggest that the condition is actually more common in minority groups Higher prevalence in low-income verses higher-income and higher- educated cohort, which suggests social risk factors (e.g., stress) in the causation of SEID No regional differences were noticed in the U.S. Systemic Intolerance Disease: Epidemiology SEID is not associated with increased all-cause mortality, but one study showed a substantially increased risk of completed suicide (Nadler, 2023) Early diagnosis and prompt treatment are critical to prevent high morbidity and the overwhelming effect on the quality of life (Sapra and Bhandari, 2023) Systemic Intolerance Disease: Epidemiology Patients report a greater frequency of childhood trauma and psychopathology, and display higher levels of emotional instability and self-reported stress, compared to individuals who do not have chronic fatigue (Nadler, 2023) Associated with a poorer quality of life, with over half of patients being unemployed As with any chronic illness, it is very common for patients to experience depression, stress, and anxiety as they navigate the ongoing challenges that the condition brings to the various aspects of their lives Systemic Intolerance Disease: Etiology Considered a biological (not psychological) disorder The exact pathogenesis is not fully understood; however, various mechanisms and biochemical changes have been shown to affect immune function, hormonal regulation, and response to oxidative stress, which may play a role in disease progression An infectious cause has been proposed, but no causal relationship has been identified to date Systemic Intolerance Disease: Possible Etiological Factors Genetics Twin studies have shown increased familial and genetic predisposition to the condition One study observed variability in specific gene expression of patients, particularly post-exercise, affecting metabolic and immune responses (Sapra and Bhandari, 2023) Other studies have identified abnormalities in the genes controlling immune modulation, oxidative stress and apoptosis (Kerr, 2018), and DNA methylation (Sapra and Bhandari, 2023) Systemic Intolerance Disease: Possible Etiological Factors Infection Various infectious triggers have been proposed: Epstein-Barr virus (EBV), human herpesvirus (HHV)-6, human parvovirus B19, enterovirus, and human cytomegalovirus Anti-HHV06 IgM antibodies and HHV-6 antigens have been detected more commonly in the peripheral blood of patients with SEID, compared to the general population (Sapra and Bhandari, 2023) Systemic Intolerance Disease: Possible Etiological Factors Immune system dysregulation In patients with SEID, there have been observed alterations in the levels of CD 21+ CD19+ and activated CD5+ cells Several studies have described the presence of autoantibodies against nuclear and membrane structures, and neurotransmitter receptors Evidence of ongoing inflammation (increased production of proinflammatory interleukins), which can explain the malaise and flu-like symptoms Systemic Intolerance Disease: Other Possible Etiological Factors Exposure to toxins, chemicals, pesticides, or heavy metals Dysbiosis of gut microbiota Muscular biochemical abnormalities Trauma/prior stressful life events Neuroinflammation Alterations in neuroendocrine system (e.g., serotonin transmission, hypocortisolism) Systemic Intolerance Disease: Development of Diagnostic Criteria Diagnosis remains debated because of the lack of a gold standard for qualifying criteria (Nadler, 2023) When the etiological factors were initially considered mainly viral, the Center for Disease Control and Prevention (CDC) U.S. presented criteria in 1988 for the diagnosis with primary focus on the physical symptoms Subsequently, the Oxford criteria (published in 1991 by a research group of psychiatrists) stated fatigue to be the primary symptom, present for at least 6 months and affecting the patient > 50% of the time (severe, disabling, and affecting mental and physical functions) Systemic Intolerance Disease: Diagnostic Criteria (CDC, 1994) Major criteria At least 6 months’ duration Does not resolve with bed rest Reduces daily activity to < 50% Other conditions have been excluded Physical criteria Low-grade fever Nonexudative pharyngitis Lymphadenopathy Systemic Intolerance Disease: Diagnostic Criteria (CDC, 1994) Minor criteria Sore throat Mild fever or chills Lymph node pain Generalized muscle weakness Myalgia Prolonged fatigue after exercise New-onset headaches Migratory noninflammatory arthralgia Sleep disturbance Neuropsychological symptoms (photophobia, scotomata, forgetfulness, irritability, confusion, inability to concentrate, depression, difficulty thinking) Description of initial onset as acute or subacute Systemic Intolerance Disease: Diagnostic Criteria The 2015 Institute of Medicine (IOM) diagnostic criteria requires the presence of the following three symptoms: 1. Substantial reduction/impairment in the ability to engage in pre-illness levels of occupational, educational, social, or personal activities. This persists for > 6 months and is accompanied by fatigue that is often profound and of new/definite onset (not lifelong), and is not substantially alleviated by rest. 2. Post-exertional malaise lasting > 24 hours 3. Unrefreshing sleep Systemic Intolerance Disease: Diagnostic Criteria The patient must also have at least one of the following two manifestations: 1. Cognitive impairment (in short-term memory, concentration) 2. Orthostatic intolerance (lightheadedness, dizziness, and headache that worsen with upright posture and improve with recumbency) Systemic Intolerance Disease: Prognosis Prognosis = Unknown Recovery is unknown in SEID Treatment is more about management – there is no existing cure Trials are on-going to find effective treatment options Current research is attempting to identify a specific biomarker that may play a role in the pathophysiology of SEID As patients with SEID possess a particular alteration in metabolism, mitochondrial dysfunction is also hypothesized to be the root cause Systemic Intolerance Disease: Prognosis Favourable outcomes are associated with less severity of fatigue at baseline, a better sense of control over symptoms, and the absence of attribution to a physical cause (Sapra and Bhandari, 2023) Patients who believe that their symptoms are related to modifiable factors (e.g., workload, stress, coping strategies, depression) are more likely to recover than those who emphasize external factors (e.g., viral infection) In one study, 90% of patients seeking support for their chronic fatigue reported greatest satisfaction when physicians provided reassurance and explanation of how physical and psychological factors are linked to psychosocial management plans (Rosenthal, 2008) Systemic Intolerance Disease: Goals of Treatment Most people are generally healthy and active before developing SEID, which makes it particularly distressing. Establishing a supportive and trusting relationship with an experienced health care provider is vital for patients to successfully cope with the condition. Relieve symptoms when possible, according to patient preferences, and maximize quality of life Patient education on self-management (e.g., pacing exercise to avoid post- exertional malaise or deconditioning), setting stepwise realistic goals, and coming to a shared understanding and identification of triggers (i.e., lifestyle, social and environmental factors) Option for patient support groups to promote self-management Systemic Intolerance Disease: Referral and Management Many patients perceive that medical practitioners and staff are more responsive to them when they describe physical symptoms Important to provide a supportive environment where patients are validated in their experience and can openly discuss their condition Scheduling an early follow-up appointment is recommended to monitor patients’ response to management plans Regular visits (e.g., every 2 weeks to 2 months), rather than sporadic urgent care appointments, can allow physicians to focus on fatigue as the main issue and re-evaluate the treatment plan Systemic Intolerance Disease: Referral and Management Patients benefit from a comprehensive multidisciplinary approach to provide psychological support and focused treatment on comorbid symptoms (insomnia, mood disorders, pain, memory and concentration difficulties) The clinician’s attentiveness in listening and providing explanatory responses can be extremely important to reassure the patient All patients should be encouraged to engage in normal activities as much as able to, and be reassured that full recovery is eventually possible in most cases Systemic Intolerance Disease: Referral and Management When to refer: Secondary organic causes of fatigue to be managed at the specialist level Infections that are not responsive to standard treatment Difficult to control hyper- or hypothyroidism Severe psychological illness Malignancy Evaluation of Fatigue Fatigue: Evaluation Detailed health history Develop a clear picture of the patient’s fatigue, including onset, duration, and exacerbating factors Inquire about associated symptoms to explore possible undiagnosed medical illness(es) Obtain a thorough medication history Obtain a detailed sleep history Fatigue: Evaluation Screen for underlying psychiatric disorders (e.g., depression, anxiety, substance abuse) Explore psychosocial issues (e.g., home life, occupation) Rule out any “must not miss” diagnoses (e.g., anemia, hypothyroidism, diabetes mellitus) Interviewing the Patient Open ended questions Tell me about your fatigue. What do you mean when you say you are fatigued? Tell me about your energy level. Has the fatigue changed your lifestyle? Tell me about any new or unusual circumstances in your life when you first noted the fatigue. Interviewing the Patient Tips for effective interviewing Distinguish fatigue from other symptoms, such as excessive somnolence (daytime sleepiness) or shortness of breath Determine the impact of the patient’s fatigue on the patient’s lifestyle and social and occupational function Identify possible precipitating events Citation: Chapter 7. Fatigue, Henderson MC, Tierney LM, Jr., Smetana GW. The Patient History: An Evidence-Based Approach to Differential Diagnosis, 2e; 2012. Available at: https://accessmedicine.mhmedical.com/content.aspx?bookid=500&sectionid=41026550 Accessed: September 06, 2024 Copyright © 2024 McGraw-Hill Education. All rights reserved Questions to Ask: Quality of the Fatigue Has your fatigue affected your ability to perform responsibilities at work or at home? Have you stopped exercising? Do you become more weak or tired with exertion? Do you become short of breath with exercise? Questions to Ask: Time Course Can you remember exactly when your fatigue started? How long have you been experiencing fatigue? Do you feel more fatigued in the morning? Do you feel tired all day? Do you feel more fatigued at the end of the day? Did your fatigue begin following surgery? Have you ever had radiation therapy? Questions to Ask: Alarm Symptoms of Fatigue Fever, night sweats Excessive thirst, urination Weight loss Abdominal pain Sore throat Jaundice Lymph node enlargement Chest pain Shortness of breath Diarrhea Palpitations Rectal bleeding Joint pain, stiffness Double vision, difficulty speaking or Back pain; diffuse bony pain chewing, pain with chewing Sleep disturbance Questions to Ask: Modifying Factors Does your fatigue only happen with exertion? Is your fatigue unrelated to physical effort? Do you feel better on the weekends? Does your fatigue improve after a good night’s rest? Questions to Ask: Personal/Social Issues Have you had more stress in your life lately? Have there been any problems in your family? Have you had more pressure at work? Have you experienced a death of a close friend or relative? When is the last time you had a vacation? Do you use alcohol (CAGE screening)? Do you use illicit drugs? Do you have more than one sexual partner? Have you recently traveled to developing countries? What medications do you take on a regular basis (prescribed/OTC)? Have you recently started taking any new medications? Questions to Ask: Psychogenic Illness How would you describe your mood? Have you been feeling sad, blue, or down? Have you lost interest in or avoided social activities? Have you experienced loss of self-esteem? Have you been more irritable or angry? Do you often feel agitated? Are you constantly worried about something? Do you experience sudden episodes of intense anxiety? If so, have you experienced chest pain, palpitations, and sweating? Has your appetite been affected? Have you had more difficulty with sleep? What is on your Differential List for Fatigue?  Psychological Cardiopulmo Rheumatologic Depression nary Fibromyalgia Infectious CHF Lyme disease Endocarditis Anxiety Hematologi COPD Mononucleosi Substance abuse c Rheumatoid PVD arthritis s Eating disorder Anemia Atypical angina SLE Tuberculosis Dysthymic Leukemia disorder HIV Lymphoma Hepatitis Somatisation Oncologic disorder Occult CMV Pharmacologic FATIG malignancy Antidepressants UE Endocrine Antihistamines Gastrointes tinal Addison disease Benzodiazepines Disturbed Diabetes mellitus Inflammatory sleep Sedative- bowel Neurologic Hypothyroidism Hypnotics disease Sleep apnea Multiple Cushing’s Opioids Irritable sclerosis Sleep syndrome Analgesics bowel deprivation Myasthenia Hyperparathyroidis syndrome gravis GERD m Antihypertensive s Cirrhosis Parkinson Allergic rhinitis Chronic kidney Constructing a Differential Diagnosis Diagnosis of SEID relies on the exclusion of chronic active organic illnesses that can produce chronic fatigue Lab results are “normal” Although a diagnosis of SEID necessitates at least 6 months of fatigue, clinical evaluation should be done in the interim to rule out other treatable causes of fatigue (Kerr, 2018) Which physical exams would you perform, and why? Fatigue: Physical Exams Vitals (BP, T, HR, RR) Oropharyngeal Exam Lymph node assessment *Additional physical exams based on patient intake and your top diagnoses and must-not-miss diagnoses Lab Testing Fatigue: Lab Testing Basic lab testing should be considered; however, studies have demonstrated limited positive predictive value of blood tests as fatigue is associated with a low pre-test probability of an underlying organic pathology (Ho and Zheng, 2022) Lab results affect management in only 5% of patients; if the initial results are normal, then repeat testing is generally not indicated (Rosenthal, 2008) Fatigue: Lab Testing CBC Thyroid function ESR Pregnancy test for women of Chemistry panel (glucose, childbearing age electrolytes, blood urea Urinalysis nitrogen BUN, creatinine, calcium), including kidney and liver function tests Classification of chronic fatigue patients. Ca2+, calcium; PO43–, phosphate. Citation: 2-10 Fatigue & Systemic Intolerance Disease (Chronic Fatigue Syndrome), Papadakis MA, McPhee SJ, Rabow MW, McQuaid KR. Current Medical Diagnosis & Treatment 2023; 2023. Available at: https://accessmedicine.mhmedical.com/content.aspx?bookid=3212&sectionid=269134168 Accessed: September 06, 2024 Copyright © 2024 McGraw-Hill Education. All rights reserved Fatigue: Additional Testing No additional tests have been shown to be useful unless the patient history or physical exam suggests a specific medical condition (Rosenthal, 2008) Fatigue: Additional Testing Consider the following only if clinically indicated: Serum cortisol Antinuclear antibody, Rheumatoid factor, Immunoglobulin levels Lyme serology HIV antibody, Tuberculin skin test Toxicology screen Chest radiography Brain MRI Echocardiography Electrodiagnostic testing Polysomnogram Electrodiagnostic Testing To assess nerve disorders Peripheral nerve disorder Myopathy Motor neuron disease (MND) Neuromuscular junction disorders Muscle pain, numbness, cramps, spasm, and abnormal twitching Traumatic injury affecting nerves and muscles Types of electrodiagnostic testing: Nerve Conduction Study Electromyography Motor conduction study of the median nerve. (MCV = motor conduction velocity; R = recording site; S1 = distal stimulation site; S2 = proximal stimulation site.) Citation: Chapter 2 Electromyography, Nerve Conduction Studies, & Evoked Potentials, Brust JM. CURRENT Diagnosis & Treatment: Neurology, 3e; 2019. Available at: https://accessmedicine.mhmedical.com/content.aspx?bookid=2567&sectionid=207223892 Accessed: October 06, 2024 Copyright © 2024 McGraw-Hill Education. All rights reserved Activity recorded during electromyography (EMG). (A) Spontaneous fibrillation potentials and positive sharp waves. (B) Complex repetitive discharges recorded in partially denervated muscle at rest. (C) Normal triphasic motor unit action potential. (D) Small, short-duration, polyphasic motor unit action potential such as is commonly encountered in myopathic disorders. (E) Long-duration polyphasic motor unit action potential such as may be seen in chronic neuropathic disorders. (Reproduced with permission from Aminoff MJ. Electrodiagnostic Studies of Nervous System Disorders: EEG, Evoked Potentials, and EMG. In: Kasper D, Fauci A, Hauser S, Longo D, Jameson J, Loscalzo J, eds. Harrison's Principles of Internal Medicine, 19e New York, NY: McGraw-Hill; 2014.) Citation: Chapter 70 General Concepts in Electrodiagnosis, Mitra R. Principles of Rehabilitation Medicine; 2019. Available at: https://accessmedicine.mhmedical.com/content.aspx?bookid=2550&sectionid=206765910 Accessed: October 06, 2024 Copyright © 2024 McGraw-Hill Education. All rights reserved Example of an obstructive apnea in a patient with sleep apnea syndrome in stage 2 sleep. The polysomnography traces from the top down are as follows: three EEG channels (C3–A2, C4–A2, OZ–A2); two EOG channels (R and L); submental electromyogram (EMG); right and left anterior tibialis EMG (RAT, LAT), electrocardiogram (ECG); nasal and oral airflow; chest and abdominal motion (CHEST and ABD). During the apneic episodes, there is abnormal airflow (both oral and nasal) with paradoxical motion of the rib cage and abdomen. At the end of the apneic episode there is a burst of EMG activity at the arousal. Following the arousal, respiration resumes with synchronous movements of the rib cage and abdomen. Citation: Chapter 98 Sleep Apnea Syndromes: Central and Obstructive, Grippi MA, Antin-Ozerkis DE, Dela Cruz CS, Kotloff RM, Kotton C, Pack AI. Fishman’s Pulmonary Diseases and Disorders, 6e; 2023. Available at: https://accessmedicine.mhmedical.com/content.aspx?bookid=3242&sectionid=270520305 Accessed: October 06, 2024 Copyright © 2024 McGraw-Hill Education. All rights reserved Diagnostic approach: fatigue. Citation: Chapter 18-1 Approach to the Patient with Fatigue - Case 1, Stern SC, Cifu AS, Altkorn D. Symptom to Diagnosis: An Evidence-Based Guide, 4e; 2020. Available at: https://accessmedicine.mhmedical.com/content.aspx?bookid=2715&sectionid=249060114 Accessed: September 06, 2024 Copyright © 2024 McGraw-Hill Education. All rights reserved Summary Fatigue is a common non-specific symptom presenting in primary care, which can be disruptive to patients' lives, especially when persistent and unexplained Fatigue is associated with a wide range of underlying etiologies; thus, history and physical examination should focus on identifying the cause Psychological/psychosocial causes are very common, as are sleep disturbances and medication impacts When considering diagnoses, look for red flags of serious illnesses in the history and review of systems, and evidence of the most common causes Summary Labs and additional testing should be used only to confirm hypotheses, and to assess for the most common causes SEID is a rare cause of persistent fatigue; other explanations should be carefully excluded Because fatigue is so common and disruptive to quality of life, and the cause is so often evasive and/or psychologic/psychosocial, it is very important to be affirming, empathic and patient-centered in the approach Building an appropriate circle of care is critical, as are early and regular follow-ups References Craig T, Kakumanu S. Chronic fatigue syndrome: evaluation and treatment. Am Fam Physician. 2002 Mar 15;65(6):1083-90. PMID: 11925084. Hui Ho DC, Zheng RM. Approach to fatigue in primary care. Singapore Med J. 2022 Nov;63(11):674-678. doi: 10.4103/SINGAPOREMEDJ.SMJ-2021-118. PMID: 36573655; PMCID: PMC9815175. Kerr, K. CPS [Internet] chapter: Chronic Fatigue Syndrome. Ottawa (ON): Canadian Pharmacists Association; c2016 [cited 2024 Sept 06]. Available from: http://www.e-cps.ca. Nadler PL, Gonzales R. Fatigue & Systemic Intolerance Disease (Chronic Fatigue Syndrome). In: Papadakis MA, McPhee SJ, Rabow MW, McQuaid KR. eds. Current Medical Diagnosis & Treatment 2023. McGraw Hill; 2023. Accessed September 06, 2024. https://accessmedicine-mhmedical-com.ccnm.idm.oclc.org/content.aspx?bookid=3212&s ectionid=269134168. References National Academy of Sciences. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Key Facts. 2015. Accessed: October 04, 2024. https://nap.nationalacademies.org/resource/19012/MECFS_KeyFacts.pdf. Sapra A, Bhandari P. Chronic Fatigue Syndrome. [Updated 2023 Jun 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557676/. Scherer K, Bedlack RS, Simel DL. Does This Patient Have Myasthenia Gravis? JAMA. 2005;293(15):1906–1914. doi:10.1001/jama.293.15.1906. Simons RJ, Swallow NA. Chapter 7. Fatigue. In: Henderson MC, Tierney LM, Jr., Smetana GW. eds. The Patient History: An Evidence-Based Approach to Differential Diagnosis. McGraw Hill; 2012. Accessed September 06, 2024. https://accessmedicine-mhmedical-com.ccnm.idm.oclc.org/content.aspx?bookid=500&se ctionid=41026550. References Statistics Canada. Canadian Community Health Survey, 2014. Accessed October 06, 2024. https://www150.statcan.gc.ca/n1/daily-quotidien/150617/dq150617b-eng.htm. Rosenthal TC, Majeroni BA, Pretorius R, Malik K. Fatigue: an overview. Am Fam Physician. 2008 Nov 15;78(10):1173-9. PMID: 19035066. Weinstein AR. Approach to the Patient with Fatigue - Case 1. In: Stern SC, Cifu AS, Altkorn D. eds. Symptom to Diagnosis: An Evidence-Based Guide, 4e. McGraw Hill; 2020. Accessed September 06, 2024. https://accessmedicine-mhmedical-com.ccnm.idm.oclc.org/content.aspx?boo kid=2715&sectionid=249060114. Yancey JR, Thomas SM. Chronic fatigue syndrome: diagnosis and treatment. Am Fam Physician. 2012 Oct 15;86(8):741-6. PMID: 23062157.