Could It Be Hypothyroidism?

A malady that mimics depression

The patient couldn't tell me what was wrong, and neither could his 80-year-old mother. He had been lying on the sofa for weeks, she said, and he wouldn't get up.

Sloth was a sin, but was it a reason to be admitted to the hospital?

They lived in a house in East St. Louis, Ill. He was 56 and single, working odd jobs until recently, when he parked himself on the couch, watching television. He was sleepy most of the time, forgetting appointments and leaving chores unfinished. When confronted, he became irritable and withdrawn.

His mother suspected drugs, but he never left the house long enough to buy any. She begged him to see a doctor, but he wouldn't. When the situation became intolerable, she called 911.

It was my first hospital rotation in medical school, but even to my novice eye this wasn't the usual midsummer lethargy.

The man moved slowly and slurred his words. He denied using drugs and said he had had no previous medical problems. Though he vaguely recalled taking a medication, he couldn't remember what it was.

His body was cool and dry. His heartbeat was slow but otherwise normal.

I asked him a few standard questions. He knew where he was and the year, but not the month or the president. I asked him to count backward from 100 by 7's, but he stopped at 93.

He wasn't intoxicated or hypoglycemic. A brain scan revealed no stroke, tumor or bleeding.

Of all the diagnostic possibilities, infections were probably the most serious. AIDS can cause premature dementia, but he didn't have the usual risk factors. Lyme disease was unlikely; the tick carriers are not endemic to the area.

What about meningitis or, worse, syphilis? Untreated syphilis can infect the spinal cord and brain, causing severe nerve damage and dementia. Syphilis is one of the great masqueraders, a disease with such varying symptoms that it can almost never be excluded with certainty. In urban areas then, the incidence of syphilis was rising. The best way to rule it out was a spinal tap.

With my resident's help, I scrubbed the man's lower back with an antiseptic soap and then injected local anesthetic into the tissue between the third and fourth vertebrae. It was my first spinal tap, and luckily the needle went right into his spinal column, returning a clear fluid. We sent the fluid off to the laboratory.

That evening, test results started coming back. Blood tests for kidney and liver disease were negative. The spinal fluid was clean, ruling out an infection. But when the level of thyroid-stimulating hormone came back, it was off the scale. The patient had the worst case of hypothyroidism the doctors had ever seen.

I ran into an E.R. resident later that night and told him we had made a diagnosis. "Let me guess," he said. "Hypothyroidism."

"How did you know?" I asked in disbelief.

"I tapped on his knee," he replied.

Later I tried it, eliciting the slow reflex that is a classic sign of the disease. Physical examination is always easier when you know the answer.

We immediately gave him thyroid medication, and after a couple of days his heartbeat sped up, his thoughts became clearer and his body temperature rose to normal. Lying in his hospital bed, he apologized to his mother for all the trouble.

Hypothyroidism can mimic many symptoms of major depression, including forgetfulness, low energy and the inability to concentrate. In 1888, the Clinical Society of London published the first major report on the disorder, calling it myxedema and comparing it to childhood cretinism. Its most severe form brings on a reduced level of consciousness and even paranoia and hallucinations.

The next day his mother brought in a brown bag. In it was an empty bottle of thyroid hormone. He had been taking the drug but had stopped six months earlier after it ran out, slowly sinking into an amnesiac delirium that made him forget he needed it, a lapse that almost cost him his life.

Hypothyroid coma has a 20 percent mortality rate even if recognized and treated appropriately.

Every day in emergency rooms, patients get inappropriate treatments because they don't carry lists of their medications. When someone rolls in unconscious, the medication list can be the most valuable piece of diagnostic information.

"Remember to write this down," I told his mother.

After what they had been through, she agreed it was a sensible plan.

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