Neurological delusions

Many delusions are neurological, rather than psychological, in origin.

Mrs. Dodd had grown impatient with her doctors. Why were they insisting that her left arm was paralyzed when she knew she could move it just fine?

In fact, she could not move her arm. Mrs. Dodd was completely paralyzed on the left side of her body after a stroke to the right hemisphere of her brain. However, it didn’t seem to bother her much; despite having spent the last two weeks in a wheelchair, she seemed blissfully unaware of her predicament and denied it vehemently.

When the doctor asked her to touch his nose with her left arm, the limb remained limp and motionless. But that didn’t stop Mrs. Dodd from exclaiming: “There, I’m touching it!” Asked to clap her hands, Mrs. Dodd merely raised her right arm and silently swung it in the air.

Mrs. Dodd was displaying an extreme form of anosognosia: the inability to perceive one’s own illness.

But what’s going on here? Is this really a neurological disorder? Isn’t the problem more psychological? Mrs. Dodd seems to be suffering from extreme denial in the face of a traumatic event. Perhaps her response is simply a psychological defense mechanism.

In some cases, there may well be a psychological component to denial. The author recalls a patient who was tragically diagnosed with terminal brain cancer. Strangely enough, the man didn’t seem concerned about the diagnosis at all; instead, he spent much of his time complaining about a blister on his forehead. On the face of it, this example seems like a clear-cut case of deflection – the mind’s attempt to divert attention away from overwhelming stress and toward more manageable problems.

While psychological explanations for denial are certainly relevant in many cases, we have reason to believe there’s a neurological basis for denial, at least in some severe cases.

The fact is, patients who exhibit anosognosia have almost always suffered a stroke to the right hemisphere of the brain. Tellingly, those who suffer a stroke to the left hemisphere actually exhibit opposite tendencies – they’re prone to obsess over their illness and fret over their chances of recovery.

In the future, we might well discover that a great many psychological problems actually have their root in neurological damage. Since traditional therapy isn’t likely to be effective in repairing physical problems, we could potentially save patients countless wasted hours on the couch.