History
A 33-year-old white female presented with a chief complaint of poor vision that had persisted for one month following a car accident. Her systemic history was unremarkable, and her ocular history was noncontributory. She took no medications and had no known allergies.
Diagnostic Data
Her best-uncorrected visual acuity was hand motion O.U. at distance and near. Extraocular muscles and pupils were normal. Refraction uncovered only negligible error. Her intraocular pressure measured 14mm Hg O.U. The posterior segment findings were normal.
Your Diagnosis
How would you approach this case? Does this patient require any additional tests? What is your diagnosis? How would you manage this patient? Whats the likely prognosis?
Discussion
Additional testing included photodocumentation; laser interferometry; Amsler grid testing; testing of the menace reflex; tangent screen visual fields; prism dissociation test; optokinetic tape or drum testing. Electrodiagnostic testing was also considered, including electroretinogram (ERG), electroculogram (EOG) and 30Hz flicker testing.
The diagnosis in this case is malingering. We requested that the patient follow us through a hallway where we purposely placed various obstacles. When she navigated the course successfully, the ruse was up. We used an optokinetic tape and the mirror test (where the patient looks at himself or herself in a mirror to confirm our suspicion). The classic method of using a tangent screen test at two different distances was not required.
Malingering is different from hysteria (loss of control) or hypochondria (the false belief that oneself is sick) because the patient knowingly and intentionally misleads examiners for a desired purpose or end.1 For example, patients who may be rewarded by large financial settlements in court may have a motive to exaggerate medical claims.2
Measures of visual function, such as visual acuity and visual fields, generally are dependent on subjective responses. In some young, elderly, cognitively impaired or malingering patients, such measurements may be difficult to obtain.1,2
But, a new instrument, the Visual Evoked Response Imaging System (VERIS, Electro-Diagnostic Imaging), provides objective topographic recordings of both retinal and cortical function.2 Electrodiagnostic flicker tests are also used frequently. Another similar diagnostic is the vertical and horizontal prism dissociation test.
Nevertheless, in any suspected case of malingering, be sure to instruct the patient to describe what he or she sees while observing his or her eye movements.4
Doing this may help you spot faulty symptomatic claims.
While there are many ways to subtly (and not-so-subtly) fool malingerers at their own game, the literature suggests that stern warnings might only deepen malingering patients desires to carry on their charades.5 Interestingly, stern warnings regarding symptom validity may actually cause malingerers to feign new or modified deficits, which could further prolong your already-unnecessary investigation.5
When we had sufficient data to suggest the presentation of mistaken symptoms, we confronted our patient and explained our thoughts. In these cases, rather than create an awkward and aggressive environment by calling the patient a faker or liar, we choose to explain how the information we collected did not make sense.
Patients who are malingering often want to tell a story, and attempting to uncover the underlying cause may actually trigger the source making the deception necessary. In some cases, patients may be hypochondriacal and genuinely believe what their saying.
In any case, embarrassing a patient by calling them out in an open or direct way may actually cause a true malingerer to just dig his or her feet in deeper and insist that the manufactured symptoms are authentic. Here, diplomacy and negotiation are the best tools to employ.
1. Friel JP. Malinger. Dorlands Illustrated Medical Dictionary, 26th ed.
2. Pearce JM. Psychosocial factors in chronic disability. Med Sci Monit 2002 Dec;8(12):RA275- 81.
3. Crewther DP, Luu CD, Kiely PM, et al. Clinical application of the multifocal visual evoked potential. Clin Exp Optom 2004 May;87(3):163-70.
4. Golnik KC, Lee AG, Eggenberger ER. The monocular vertical prism dissociation test. Am J Ophthalmol 2004 Jan;137(1):135-7.
