The Challenge: A 63-year-old painter develops headaches that become increasingly devastating, associated with changes in the way he sees and interacts with the world. Can you explain why?

Every month the Diagnosis column of The New York Times Magazine introduces Well readers to a real-life patient and asks them to consider the patient’s story and symptoms, along with the medical records, to try to come up with a diagnosis that can explain it all. Today we offer the case of a retired magazine art director who develops excruciating headaches, which seem to change both what he sees and how he thinks.

As his headaches become more frequent and more ferocious, the patient becomes withdrawn, forgetful and easily angered. His paintings change from open landscapes to dark fields of underground serpents and half-destroyed houses. He sees a series of doctors who can’t quite figure it out and refer him on until he finally reaches a doctor who asks the right question and puts it all together.

I will provide the information and images available to the doctor who made the diagnosis. You can provide the question you would like to ask to help you make a diagnosis. As usual, the first reader to correctly identify the cause of this man’s strange symptoms and come up with the question that led to this right answer will get a copy of my book, “Every Patient Tells a Story,” and that great sense of achievement that comes from solving a puzzle that can save a life.

Headache From Hell

The 63-year-old man in the backseat was asleep, his head bobbing gently with the motion of the car as it sped across the Golden Gate Bridge. His wife sat silent, grateful to her daughter-in-law for driving them to see yet another neurologist and thinking about how much the man she’d married 38 years before had changed over the past year.

It seemed to have started with the headaches. He was such a tough guy, so stoic, who never complained, so she really had no idea when he first got them, but he first mentioned them maybe nine months earlier. Since then they’d gotten fiercer and more frequent.

Recently she’d found him lying with his face pressed against the cool tiles of the bathroom. He wouldn’t get up. His head throbbed too much. He’d rather be dead, he told her, than continue with these headaches.

A Different Man?

Then, four to five months ago, the patient’s wife started noticing other things. Little things. Things so subtle that she wasn’t always sure at times if it was him — or her.

He seemed to get quieter. Her husband was never a big talker, but if you asked him about something he’d tell you what he knew and offer an opinion. These days when asked, he’d often just grunt or shrug — like he didn’t care, or didn’t know.

She’d asked him about it, and he looked surprised. He didn’t know what she was talking about, he snapped.

And it wasn’t just that. He was clumsier. He seemed to trip a lot. And when he walked or drove, he drifted to the right. He’d never hit anything, but he’d come mighty close.

At home he had always been very organized. Thought that there was a place for everything. But lately, she’d find things put in the wrong place. The silverware with the plates; his sweaters in her dresser drawers. It was strange. He’d just look at her like she was nuts when she pointed it out.

Seeing Differently?

Her husband had been a painter throughout their marriage. And since retiring he’d switched from acrylic paints and started working in oil. He’d begun by creating bucolic landscapes. But over the past few months his scenes had become darker and more menacing. It was a different medium, she figured, and so lent itself to a different subject matter — far from his bright and cheerful acrylic paintings.

You can see an early oil painting here.

And a painting done several months later here.

Was it the paint or what the patient saw that had changed?

A recent trip to one of those huge warehouse stores made her suspect the latter. After entering, her husband turned to her and exclaimed, “Oh, they changed the layout here.” She glanced around; it looked no different to her. The aisles are diagonal now, he said, gesturing off to the right, as if they headed that way. They’re not diagonal, she protested. He didn’t respond.

One evening, not long afterward, she sat down and made a list of all the little changes she’d noticed in her husband. It was a long list and she was worried.

An Abnormal Brain Scan

By this point, the patient had seen several doctors about his headaches. When his headaches worsened despite treatment, his regular doctor sent him for an M.R.I. She called as soon as she saw the results. The M.R.I. was clearly abnormal.

The tough tissue that surrounds the brain — the meninges — is normally seen in imaging as a crisp thin line delineating the outer edge of the brain. In the painter’s scan, that line was thick and lumpy — completely abnormal looking.

You can see an image from the M.R.I. here, with an arrow pointing to the meninges.

You can also read the radiologist’s M.R.I. report here.

The Doctors Weigh In

The doctor referred the patient to one neurologist, and when that didn’t pan out, he saw another and then another. All three specialists agreed that the abnormal scan suggested something had invaded the brain — perhaps an infection, or maybe a cancer spread from some other part of the body. A second M.R.I., done just a few weeks later, looked even worse than the first.

The patient had a spinal tap to look for infection or malignancy. And although there was no evidence of either of those, the spinal fluid did contain more protein than was normal, and that suggested some type of inflammatory process going on in the brain.

And so they headed to the University of California, San Francisco, to see their fourth neurologist, Dr. Jeffrey Gelfand, a specialist in sarcoid and other inflammatory diseases of the brain that could cause the lumpy changes seen in the scan.

It had taken them nearly a month to get the appointment. Their insurance company was unwilling at first to pay for the new consultant. The wife, now certain of the changes in her husband, wrote to Dr. Gelfand pleading for an appointment, which had thankfully come through, with the insurance company’s reluctant blessing.

You can see the wife’s note here.

Expert Eyes

The woman woke her husband when they arrived at U.C.S.F., and wife and daughter-in-law helped the man out of the car and to Dr. Gelfand’s office. The neurologist greeted them and quickly focused on the patient.

Dr. Gelfand liked to get patients to tell the story of their illness. How it was told was often as useful as what was said. But this patient wasn’t able to tell a story. When Dr. Gelfand asked a question, it was followed by a long silence, as if the man was considering the answer. The patient would often repeat the question, then hesitate again before answering. His answers were brief, and his speech was quite slow.

Dr. Gelfand had the notes from the previous doctors the patient had seen already and both M.R.I.s. He turned to the wife when her husband’s answers needed clarification or details and was able to put together the patient’s story.

You can see a copy of Dr. Gelfand’s note here.

A Touch Test

Other than his remarkable slowness of speech, the patient’s exam was pretty normal until Dr. Gelfand asked the patient to touch his own nose and then to reach out and touch the doctor’s finger, which was held out in front of him. As the man reached out toward the doctor, his hand zig-zagged dramatically and he couldn’t direct his finger to the tip of the doctor’s finger as instructed. A simple task, and yet the man found himself unable to do it, with either hand.

After reviewing the M.R.I.s with his own neuroradiology team, Dr. Gelfand was worried that the bloated, lumpy meninges might reflect some problem in the blood flow into or out of the lining of the brain. So he referred the patient to Dr. Wade Smith, a neurologist who specialized in diseases of the blood vessels of the brain.

It was Dr. Smith who finally asked the question that led to the right diagnosis.

Solving the Mystery

Can you come up with the question Dr. Smith asked?

And can you figure out the diagnosis?

Put your answers in the comments section. As usual, the first person to get the correct answer will get a copy of my book and the honor of figuring out this tough, tough case.

Rules and Regulations: The winner will be contacted. Reader comments may also appear in a coming issue of The New York Times Magazine.