Date sent:      	Wed, 13 Dec 2000

The Differential Diagnosis of CFS and MS

Dr. Charles M. Poser, MD, FRCP (GLE),
Visiting Professor of Neurology, Harvard Medical School

The CFS Research Review, Fall 2000 (1) 4:6-8

Reprinted with permission from The CFIDS Association of America.
©2000.  The CFIDS Association of America. www.cfids.org.
800-442-3437.

[This article has been electronically scanned and proofed; we apologize
for are any mistakes or misspellings in the transcription.]

     An alarming number of CFS patients are misdiagnosed with multiple
sclerosis (MS). The severity and symptoms of chronic fatigue syndrome
(CFS) fluctuate and sometimes mimic the relapses and remissions of MS.
In addition, when health care practitioners suspect a patient has MS, they
almost always refer the patient to a neurologist, who then sends them for
magnetic resonance imaging (MRI) testing. Today, unusual cerebral white
matter on MRI tests often automatically leads to the diagnosis of MS.
     In a review of 366 patients referred to me who had been diagnosed with
MS by a board-certified neurologist, only 236 patients (65%) had been correctly
diagnosed.  An astounding 28 (22%) actually had CFS.(1)
     The extent of the misdiagnosis of MS is disturbing, particularly in light of the
current therapeutic frenzy dictating the immediate initiation of expensive,
disease-modifying drugs of still unproven, long-term efficacy, such as interferon
beta. Further, no studies have been done to determine the short- and long-term
effects of giving such drugs to CFS patients, who may be incorrectly diagnosed with
MS.
     This article attempts to clarify the neurological abnormalities and symptom
presentations of both conditions because of this overreliance on MRI testing and
misinterpretation of MRI test results.

DIAGNOSTIC TESTS
There are no definitive diagnostic tests for either CFS or MS but because
MRI tests are commonly ordered, there are some subtle differences
practitioners can look for.  In CFS patients, MRI studies may reveal areas
of increased signal intensity in the white matter of the central nervous system
(CNS), which are generally punctate rather than ovoid in size and are scattered
throughout the white matter, usually at the periphery near the white-gray junction.
In MS patients, increased signal intensity in the white matter of the CNS is usually
found in the periventricular areas.
     Changes in cerebrospinal fluid have also been reported in CFS patients,
such as leukocytosis, elevated IgG synthesis and oligoclonal bands in a very
few patients.(2)
     Consequently, practitioners must not rely on MRI findings alone for patients
diagnosed with MS, but consider the patient history and the neurological examination.

SYMPTOMS
Although CFS can often present in the same manner as MS, there are
many differentiating symptoms, including neurological, cardiovascular,
gastrointestinal, autonomic and muscular conditions.
     NEUROLOGICAL SIGNS AND SYMPTOMS.   Neurological signs and
symptoms are rare in CFS. Henderson and Shelokov found signs of paresis,
diplopia, urinary retention, facial paresis and the Babinski's sign in their
review of patients involved in recorded outbreaks of CFS.(3)    Komaroff
and Buchwald also reported seeing ataxia, focal weakness and transient
blindness in CFS patients.(4,5)
     Although these symptoms are also found in MS patients, Babinski's sign,
paresis or paralysis are much more common in MS patients, as are gait
disturbances, foot drop and a "pins and needles" numbness.
     On the other hand, some neurologists have found no neurological
abnormalities in their CFS patients. (6,7,8)   This may be due to the fact
that neurological symptoms in CFS patients don't always have a set pattern.
As at least one researcher noted, "A [CFS] patient examined in the morning
might have nystagmus, which would disappear at midday, recur later,
disappear again and recur the next day.  This on-again, off-again pattern is
typical of CFS." (9)
      MS and CFS patients will both complain of feeling dizzy or lightheaded.
MS patients experience nonpositional vertigo and ataxia, losing their balance
on the Romberg test, but CFS patients do not have true ataxia.  Rather, CFS
patients experience a sensation of disequilibrium. They may also have
orthostatic intolerance or syncope.  CFS patients will report ringing in the
ears and headaches, which is also uncommon in MS patients.
     Neurological symptoms that are rare in CFS patients but typically occur
in MS patients include monocular color blindness, hemifacial spasms, gait
ataxia, optic/retrobulbar neuritis, unilateral intention tremor, scanning speech,
binocular diplopia, trigeminal neuralgia, monoparesis and transverse myelitis.
     MS patients rarely report cognitive problems, but cognitive problems are
common in CFS patients, usually manifesting as impaired memory or
concentration or information processing difficulties, often described as "brain
fog."
     MUSCULAR PAIN AND SENSATIONS. CFS patients often complain of
pain. Acheson emphasized that "pain, invariably present, may be devastating
and is perhaps the feature that impresses itself most forcibly on the observer."(10)
Muscle pains are not part of the clinical picture of MS, however.
      Most CFS patients will also experience migratory paresthesiae, often with
a painful burning sensation that moves from one part of the body to another
within a matter of hours or days. MS patients do not experience migratory
arthralgias or joint pains.
     MEDICATION RESPONSES.  CFS patients often have paradoxical or unusual
reactions to even low doses of medications, but MS patients don't. Most of the
symptoms of CFS do not respond to corticosteroids, used to reduce the severity
of MS relapses.
     OTHER SYMPTOMS. Gastrointestinal symptoms such as irritable bowel
syndrome, nausea, vomiting and diarrhea are common in CFS patients.
MS patients, however, more frequently experience bowel retention or
incontinence.  Cardiovascular problems in CFS patients include increased
orthostatic blood pressure and rapid pulse.  General weakness and
postexertional malaise and fatigue are also very common in both CFS and
MS patients. CFS patients often experience fevers, chills and sore throat at
the onset of their illness, characteristics that are extremely unusual in MS
patients.

CLINICAL SUGGESTIONS
Enough differences exist between CFS and MS that clinicians should first
conduct an exhaustive patient history and examine all signs and symptoms.
The combination of fatigue, two of the major and two of the minor symptoms
is strongly suggestive of the diagnosis of CFS (see Table 1).  Patients and
health care practitioners could better serve patients by not accepting an MS
diagnosis based on MRI findings alone. Many MRIs are interpreted by
radiologists who are not adequately trained to differentiate white matter
abnormalities that may mimic MS.  Further, many neurologists often fail to
obtain a complete patient history or even view the actual MRI film, which is
sometimes incorrectly interpreted by radiologists.


REFERENCES
(1) Poser C et al. Ann Neurol. 1983; 13: 227-231.
(2) Warner C et al. Neurology 1989; 39 (1):420.
(3) Henderson D et al.  NEJM 1959; 260: 757-764.
(4) Komaroff A in Hyde D (ed.) The clinical and scientific basis of myalgic
encephalomyelitis/chronic fatigue syndrome. The Nightingale Research
Foundation, Ottawa, Ont. Canada. 1992: 228-34.
(5) Buchwald D Ct al. Ann Int Med 1992; 116:103-113.
(6) Lane R in Hyde D(ed.) The clini-cal and scientific basis of myalgic
encephalomyelitis/chronic fatigue syndrome. The Nightingale Research
Foundation, Ottawa, Ont. Canada. 1992: 395-9.
(7) Behan Petal. J Infect 1985 10: 211-22.
(8) Buchwald D et al. JAMA 1987; 257: 2303-7.
(9) Pellew R. Med J Austral. 1951; 1: 944-6.
(10) Aeheson E. Am J Med 1959:26: 569-95.


TABLE 1:  CLINICAL CHARACTERISTICS OF CFS

MAJOR SYMPTOMS
Fatigue
Migratory myalgias
Migratory arthralgias
Migratory painful paresthesiae
Memory and cognitive disturbances

MINOR SYMPTOMS
Dizziness
Sensation of disequilibrium
Sleep disturbance
Anhedonia
Unusual reactions to medications