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Spring 2003

CFS Case Study: Diagnostic Basics

Below is a case study adapted from “Chronic Fatigue Syndrome: A Diagnostic & Management Challenge,” a CFS curriculum for primary care providers. The program can be used by physicians, nurses and physician assistants to earn continuing education credits. For more information on the program, visit http://www.cfids.org/resources/print-self-study-module.asp, or contact Terri Lupton, coordinator for educational opportunities at The CFIDS Association of America, at tlupton@cfids.org.

Patient description: Rita is a 57-year-old white female who works part time as a receptionist at a beauty salon.

Chief complaint: “I am always exhausted and never really feel well. I have difficulty remembering things, like what I need when I’m at the grocery store.”

History of present illness: She describes the onset of her illness as occurring at age 43. Her symptoms began with a viral illness, e.g., fatigue, muscle and joint pain and upper respiratory symptoms. She also noted difficulties with concentration and increasingly severe allergies. Sometimes she feels nearly normal for months at a time, but then her symptoms return and she has difficulty managing family responsibilities. Spring and summer are her most severe periods. She has no history of depression, but states that her mood can be sad or even hopeless after several months of unremitting symptoms.

Currently, she has had a lot of symptoms and has been unable to work more than 20 hours a week. Forgetfulness, worsening pain in the hips, knees and lower back, difficulty falling asleep after waking during the night and awakening utterly exhausted in the morning are the most disabling symptoms. Light activity such as an hour of shopping or handling errands leads to increased fatigue and a sore throat for the next 1–2 days.

Question: What are some of Rita’s symptoms that could indicate chronic fatigue syndrome (CFS), based on the 1994 international case definition? (Select all that apply.)

A)        Joint and muscle pain

B)        Sore throat

C)        Seasonal nature of symptoms

D)        Disturbed sleep

E)        Post-exertional malaise that lasts for 1–2 days

F)        Lower back pain

G)        Substantial impairment in short-term memory or concentration

Answer: A, B, D, E, G

Of the eight symptoms that are described by the 1994 case definition, Rita currently reports having six: joint pain, muscle pain, sore throat, disturbed sleep, post-exertional malaise and substantial impairment in short-term memory or concentration. The other two symptoms in the case definition, headaches of a new type and severity and tender lymph nodes, are elicited during the review of Rita’s symptoms and the physical exam.

Question: Which one of Rita’s symptoms is relatively unique to CFS?

A)        Joint & muscle pain

B)        Sore throat

C)        Disturbed sleep

D)        Post-exertional malaise that lasts for 1–2 days

E)        Fatigue

Answer: D

Post-exertional malaise is one of the hallmarks that should lead a provider to suspect a diagnosis of CFS. Typically the patient describes 1–2 days of increased malaise and symptoms following even slight overexertion. Additional symptoms can indicate other illnesses ranging from Lyme disease to cancer, but the post-exertional malaise is fairly specific to CFS.

The provider taking the history should examine the nature of the “fatigue.” In people with CFS, fatigue is typically exacerbated by physical or mental tasks previously achieved with ease. Recovery from periods of worsened fatigue can take days. Pathological fatigue can be differentiated from somnolence (because it is not relieved by sleep) and from neuromuscular weakness (because people with CFS can generate muscle strength and endurance when circumstances demand a response).

Question: Which one of these CFS symptoms contributes to worsening of others and should be addressed even before a firm diagnosis can be established?

A)        Muscle pain

B)        Sore throat

C)        Disturbed sleep

D)        Headaches

E)        Fatigue

Answer: C

Disturbed sleep, described often as unrefreshing sleep, is very common in people with CFS and is shown in various studies to exacerbate other symptoms such as musculoskeletal pain, irritability and problems thinking.

Although patients with CFS usually report an increased total sleep time, sleep is typically broken and nonrestorative. Also common are frequent napping during the day and a change in circadian rhythm, i.e., a late-night to late-morning sleep cycle.

Restoration of refreshing sleep is a goal of management in the patient with CFS. This goal may be achieved by establishing proper sleep hygiene through:

Avoiding daytime naps, especially late in the day

Scheduling even gentle exercise activities at least 3–4 hours before bedtime

Establishing a regular bedtime and waking routine 

Limiting food intake for the two hours prior to bedtime

Using analgesics or non-steroidal anti-inflammatory drugs for relief of musculoskeletal pain or headache.

Review of symptoms

Headache: Occurs three or four times per week, usually begins at work, frontal pressure, takes Tylenol Sinus for headaches with modest relief.

Sore throats: Occasional, during episodes of most severe fatigue.

Cough: Occasional morning cough, nonproductive, and clears with the first morning coffee.

Chest: No wheezing or pain.

Cardiovascular: Palpitations at night occasionally, sometimes while standing for lengthy periods.

Abdomen: Diagnosed to have irritable bowel, reflux; taking both Axid (nizatidine) and Donnatal.

Genito-urinary: Frequent urinary tract symptoms, cultures always negative.

Extremities: Pain in lower extremity increases when standing for long periods, pain on right side on awakening, improved in one to two hours.

Neurological: Notes at the onset of the illness she had vertigo that persisted for two or three months.

Current Medications

Donnatal, Axid (nizatidine, Tylenol Sinus, Xanax (alprazolam) 0.5 mg hs, Prozac (fluoxetine hydrochloride) 10 mg, Synthroid (levothryoxine sodium) 0.125, antacids, multi-vitamins, vitamin C 4g, St. John’s wort, ginkgo biloba, Echinacea.

Question: Given Rita’s symptoms, what are some disorders and conditions that would need to be ruled out before making a diagnosis of CFS? (Select all that apply.)

A)        Muscle weakness (neuromuscular disease)

B)        Dyspnea and effort intolerance (cardiac or respiratory disease)

C)        Somnolence (primary sleep disorders)

D)        Autoimmune diseases

E)        Major depression as the primary cause of fatigue and cognitive problems

Answer: All of the above.

Neuromuscular disease causing muscle weakness, and cardiac or respiratory disease causing dyspnea and effort intolerance, can present like CFS. Somnolence, primary sleep disorders and chronic sleep deprivation also cause some similar symptoms. Early symptoms of auto-immune diseases such as systemic lupus erythematosus, multiple sclerosis, Sjogren’s syndrome and rheumatoid arthritis may mimic CFS symptoms and tend to evolve slowly. Providers considering a diagnosis of CFS should monitor changes in symptoms over time and should continuously rule out these and other serious illnesses in their patients.

Distinguishing CFS from major depression is one of the most difficult differential diagnoses to make. Major depression generally leads to a loss of motivation and pleasure and rarely includes physical symptoms such as sore throat, muscle and joint pain and fever. The 1994 international case definition recognizes that depression can occur with CFS but excludes those with a history of melancholic major depression or severe psychiatric disorders for research purposes.

Physical findings

Vitals: BP 140/85; pulse 78 sitting; temperature 98.4

Weight: 210 pounds (has gained 25 lbs. since hysterectomy)

Head, eyes, ears, nose, throat: Nasal turbinates boggy; slightly tender, enlarged lymph nodes

Lymphatic: Some axillary tenderness without adenopathy

Chest: Clear

Heart: No murmur

Abdomen: Nontender, hyperactive bowel sounds over right lower quadrant

Extremities: No edema, some numbness in median nerve

Musculoskeletal: 11 of 18 fibromyalgia tender points present; Thenar wasting right hand with pain on range of motion; osteoarthritis in left hand

Neurological: Mini mental exam score: low normal.

Cranial nerve: 2–12 intact, some difficulty with tandem gait, heel to toe. Reflexes normal throughout, muscle strength 3 of 4 in large muscle groups of legs, stands by pulling up from chair.

Question: What conditions may co-exist with CFS? (Select all that apply.)

A)        Fibromyalgia

B)        Exposure to chemicals or toxins causing increased sensitivity to these substances

C)        Other adequately treated disorders, such as hypothyroidism

Answer: All of the above

All three of these conditions may co-exist with CFS, even under the strict 1994 case definition. Fibromyalgia is associated with a number of symptoms that overlap with CFS, including prolonged fatigue, cognitive dysfunction and widespread muscle pain.

A hallmark of fibromyalgia is the presence of at least 11 of 18 discrete tender points that hurt when mild pressure is applied.

Sensitivity to various chemicals and environmental toxins such as solvents, pesticides or heavy metals is often associated with CFS.

If a physician can verify that another disease process has been treated adequately and yet symptoms of CFS persist, a diagnosis of CFS should be considered. For example, if hypothyroidism is adequately treated with replacement thyroid hormones but relevant symptoms continue, an additional diagnosis of CFS may be made.

Question: Based on the history and physical exam, what laboratory tests are appropriate to rule out other causes of symptoms? (Select all that apply.)

A)        Full blood count and ESR

B)        Serum electrolytes, calcium and creatine

C)        Liver function tests

D)        Thyroid function tests

E)        Urinalysis for blood, protein and sugar

Answer: All of the above

Full blood count and ESR can rule out anemia or trigger a search for other evidence of autoimmunity or chronic infection. Serum levels of electrolytes, calcium and creatine help rule out metabolic and renal disorders. Biochemical liver function tests help evaluate possible underlying liver disease. Thyroid function tests will help detect either hypothyroidism or hyperthyroidism as the cause of symptoms since either may present in a very similar fashion to CFS; however, hypothyroidism may co-exist with CFS. Urinalysis for blood, protein and sugar can assist in ruling out common medical

conditions, which could explain fatigue and other symptoms.

Results of medical tests ordered after the initial patient visit

CBC: Hgb 12.2; HCT 39; MCV 89

Chem 23: normal with exception of mildly elevated SGOT

ANA: 1:20, rheumatoid factor negative, ESR=3

Thyroid function tests: normal

IgE: 125

IgG, A, M: normal range

Chest X-ray: no acute infiltrates

EKG: normal sinus rhythm, rate 73

Assessment

CFS

Fibromyalgia (although diagnosis confounded by overall use of medications)

Dysuria (may be secondary to vitamin C excess)

Allergic overlay likely, elevated IgE and allergic rhinitis/sinusitis on physical exam

Overlay of depression

Significant cognitive complaints warrant neurocognitive assessment

Management of patient should begin with treatment of allergies and sleep disturbances. Referral to specialist for neurocognitive assessment may yield findings important for any future disability claim, as well as rehabilitation strategies.

An understanding, empathetic approach by the provider can be very important in establishing coping strategies that help the patient to lead as full a life as possible within the limitations imposed by the illness.