Conditions That Mimic Physical Disease
It is essential to differentiate organic illness from psychogenic illness in patients complaining of physical symptoms. Patients with physical complaints in whom no medical illness can be found or who do not improve with treatment (or both) are common (1). These frustrating patients often exhaust one doctor after another and usually are finally labeled “hysterics” or “crocks.” This occasionally angry response by the physician does a disservice to these patients because, although some may be consciously “faking it” (e.g., malingering), most patients have as yet undiagnosed organic conditions or have symptoms that are unconsciously and involuntarily produced.
Several discrete involuntary psychiatric syndromes (somatoform disorders; see later) mimic organic disease. These disorders have typical clinical presentations, family histories, recommended treatments, and likely prognoses.
Failure to identify an organic etiology for a physical symptom does not necessitate a diagnosis of a somatoform disorder or malingering; these are not diagnoses by exclusion but rather should be based on specific characteristics. Consider the following diagnoses in any patient with a poorly specified or uncertain medical condition.
UNDETECTED PHYSICAL ILLNESS
The possibility of an underlying unrecognized illness must continue to be considered throughout the course of diagnosis and treatment, however long. Follow-up studies find 15% to 30% of conversion reaction diagnoses to represent misdiagnosed organic disease. Physical illness may produce symptoms that mimic a somatoform disorder or may predispose susceptible patients to concurrent psychiatric conditions (it’s not “either, or”). Some patients with subtle central nervous system (CNS) disease are at risk for conversion symptoms, so always carefully evaluate neurologically. The physical conditions
commonly found (on follow-up) among these “false-positive hysterics” include
commonly found (on follow-up) among these “false-positive hysterics” include
CNS disease, particularly epilepsy, multiple sclerosis (MS), and postconcussion syndrome, but also CNS infections (e.g., encephalitis), dementia, brain tumor, and cerebrovascular disease.
Degenerative disorders of musculoskeletal and connective tissues, including systemic lupus erythematosus (SLE), polyarteritis nodosa, early rheumatoid arthritis, and myasthenia gravis.
Others: Syphilis, tuberculosis (TB), hyper- and hypothyroidism, hyperparathyroidism, porphyria, hypoglycemia, duodenal and gallbladder disease, pancreatic disease, etc.
Be suspicious of any somatoform disorder that develops late in life—very unlikely. Psychological testing is of little help in differentiation; do not be misled by a “neurotic” picture on the Minnesota Multiphasic Personality Inventory (MMPI) into prematurely abandoning the search for a physical cause.
SOMATOFORM DISORDERS
Conversion Disorder (DSM, p. 492, 300.11)
A patient whose predominant problem is an obvious loss of function, incompatible with known physiology and anatomy, of some part of the nervous system that no identified organic pathology can completely explain (conversion symptom) may have a conversion disorder (2). Conversion symptoms include, among others:
Motor: Paralysis, astasia—abasia, seizures, urinary retention, aphonia, globus hystericus (a very distressing “lump in the throat” that makes swallowing difficult);
Sensory: Paresthesia, anesthesia, anosmia, blindness, tunnel vision, deafness;
Other: Unconsciousness, vomiting.
In addition, the particular symptom appears to serve one of two specific psychological purposes.
As primary gain, the symptom “buries” an unconscious mental conflict. An unacceptable painful thought is repressed, and the emotional energy is converted to a physical symptom. Usually the specific symptom “chosen” represents the conflict symbolically (e.g., in the negligent mother of a burned child, anesthesia develops over the corresponding part of her body).
As secondary gain, the symptom gets the patient something he or she wants (e.g., paralysis permits dependency on wife or justifies workman’s compensation) or allows him or her to avoid something unwanted (e.g., seizures prevent a court appearance).
As obvious as these relationships may be to the observer, the patient is unaware of them (unconscious), and the patient does not grasp their significance, even if explained (lacks insight).
Diagnosis
In the apparent absence of organic pathology, it is necessary to identify features in addition to a presumed conversion symptom before making the diagnosis. Realize also that as many as 25% of patients with conversion disorders have associated organic pathology (e.g., epilepsy in a patient with pseudoseizures is common), so also investigate symptoms only partially explained by the physical abnormalities. Features associated with conversion disorders include the following:
The symptom occurs abruptly and frequently follows an acute stress.
Often a history exists of the same or a different conversion symptom.
The disorder usually is seen first during adolescence or in the 20s and in a person predisposed by a dependent, histrionic, antisocial, or passive-aggressive personality disorder.
The patients often have associated moderate anxiety and depression.
The patients are frequently immature, shallow, and demanding, although they tend to cooperate with examinations. They tend to have lower intelligence, limited insight, and lower socioeconomic status. This occurs primarily in women.
Indifference to the symptom may be found (la belle indifference).
The individual neurologic symptoms usually have some characteristics that distinguish them from those of an organic etiology. In general, they tend to be variable, atypical, and inconsistent with anatomy.
▪ Conversion Seizures
Seizures (3) are often atypical and bizarre (the patient may laugh or cry throughout the seizure) but usually purposeful. Only infrequently is there incontinence, cyanosis, physical self-harm, tongue biting, or complete loss of consciousness during the seizure.
Awareness of surroundings and good muscle tone are preserved during the typically brief postictal stage (arm dropped onto face may land lightly or miss the face altogether; patient may resist eye opening). The seizure onset may be slow but also often dramatic, and seizures usually occur when the patient is around others. Set the patient quickly upright—seizures often stop.
▪ Conversion Unconsciousness
The loss of consciousness is usually light and incomplete, with the patient showing some awareness of environmental events, particularly when he or she feels unobserved. VS and reflexes are normal, and the patient usually responds to painful stimuli. The eyes are held tightly shut, and some movements may be purposive (e.g., move to keep from falling from examination table).
▪ Conversion Paralysis
The paralysis is often variable, even during one examination. Paralysis of one limb, part of a limb, or hemiparesis is most common, but the specific involvement is often inconsistent with anatomy, and the related changes (e.g., tone) are atypical. DTR changes are variable, and pathologic reflexes (e.g., Babinski) are not present. The paralyzed limbs often show little resistance to passive movement but resist the pull of gravity. If resistance to a forced movement occurs, it tends to give way abruptly (vs. gradually, as in organic conditions). Movement may occur when the patient is startled by a painful stimulus. Palpate the antagonists— they often contract to simulate agonist weakness. Usually associated conversion sensory changes are found.
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
