HISTORY: A sudden vision
Ms. K, 73, was in reasonably good health when one day she suddenly noticed red, green, and yellow birds and butterflies covering her wall.
Ms. K, who lives alone, was frightened at first, but she did not immediately alert anyone because she thought she “was just seeing things, and they’ll go away.”
Instead, she saw more visions over the next 3 months. She once “watched” as two doctors and a nun carried a middle-aged burn victim into her apartment. She remembers seeing the doctors put a “patch” over the woman’s body. To Ms. K, this experience seemed so shockingly real that she called 911, reporting, “That woman should have been in the hospital!”
She reports that a pack of butterflies once “followed” her to the market. She vividly recalls how they crawled about her shoes and legs as she entered the store. When asked if anyone noticed her insect-covered extremities, she replied matter-of-factly, “Maybe it’s not for them to see, maybe it’s just for me,” as if her hallucinations were a divine gift.
Ms. K’s hallucinations usually occur at home, where she spends most of her time. She says that the images are fleeting, lasting from a few seconds to several minutes, and that the creatures fly silently around her room.
Ms. K’s daughter grew concerned that the hallucinations were increasingly diminishing her mother’s ability to care for herself. She brought Ms. K into our emergency department, from which the patient was admitted.
On admission, Ms. K said she had lost 20 lbs within 6 months, and that “concentrating on those things in the house” was impairing her sleep. She denied recent illness, trauma, loss of conscious ness, changes in medications, seizures, drug or alcohol use, suicidal or homicidal ideation, or specific stress in her life. She added that she often cooks for herself—only to lose her appetite after seeing bugs and other creatures crawl into her food.
Her medical history includes hypertension, type 2 diabetes mellitus, peripheral vascular disease, urinary incontinence, gastroesophageal reflux, glaucoma in her left eye, and bilateral cataracts. She denies any psychiatric history and adds that she had never experienced hallucinations until about 3 months before hospitalization. She also denies any history of auditory, tactile, or olfactory hallucinations.
Would you suspect a primary psychotic illness? What clinical tests might help us understand Ms. K’s progressively debilitating visual hallucinations?
The authors’ observations
Ms. K’s case places us at the crossroads of psychiatric disturbances and medical conditions that can present as or precipitate apparent psychiatric symptoms. Delirium, dementia, psychosis, endocrinopathies, encephalitis, electrolyte disturbances, drug abuse/withdrawal, and occipital or temporal lobe seizures are all possible differential diagnoses (Table 1).
A cognitive function screening and a battery of laboratory tests, imaging scans, and neurologic and vision exams are needed to uncover the cause of her hallucinations.
EVALUATION: Looking for clues
Ms. K’s left pupil was fixed at 6 mm and did not respond to light, while the right pupil was regular and reactive to light at 3 mm. Using a Snellen eye chart, her visual acuity was poor: 20/100 to 20/200 in her right eye and less than 20/200 in the left eye. She scored a 29 out of 30 on the Folstein Mini-Mental State Examination (MMSE), indicating her cognition was intact. The remainder of the neurologic exam was unremarkable.
At admission, Ms. K’s medications included metoprolol, 100 mg qd, for hypertension; lansoprazole, 30 mg qd, for gastroesophageal reflux; tolterodine, 2 mg bid, and oxybutynin, 10 mg qd, for urinary incontinence; repaglinide, 2 mg bid, for type 2 diabetes; and three ophthalmic agents: brimonidine, prednisolone, and dorzolamide/timolol. The patient had been maintained on these medications for more than 2 years with no recent changes in dosing.
Results of Ms. K’s lab studies were normal, including a basic metabolic panel, CBC, liver function tests, urinalysis, B12, thyroid panel, rapid plasma reagin test, and urine drug screen.
A head CT without contrast revealed chronic small-vessel ischemic white matter disease and a chronic infarct of the left cerebellar hemisphere. No acute intracranial hemorrhages, masses, or other abnormalities were noted. No seizures were seen on EEG.
Table 1
Common causes of visual hallucinations
| Schizophrenia |
| Delirium |
| Dementias |
| Substance-induced psychosis |
| Electrolyte disturbances |
| Occipital and temporal lobe epilepsy |
| Charles Bonnet syndrome |
What do the laboratory and imaging tests reveal about Ms. K’s hallucinations? Is her diagnosis delirium? Alzheimer’s or other type of dementia? Schizophrenia?
The authors’ observations
Visual hallucinations—often of deceased parents or siblings, unknown intruders, and animals—can occur in up to 25% of patients with Alzheimer’s-type dementia.1 Also, patients with Lewy body dementia often present with well-formed visual hallucinations, which are thought to result from temporal lobe involvement by the characteristic Lewy bodies.