Grace sits comfortably in her well-padded wheelchair, enjoying dinner.  The California sun slants low through her nursing home window and before she’s finished, slips down the backs of the west valley hills.  She eats her food slowly, but Mom is a bright 91-year-old lady who’s really still quite sharp.  And although she struggles with dimming vision from macular degeneration, she finishes her meal by herself and is now feeling content and talkative.

So we begin to share all the latest gossip in that close, confidential way mothers and daughters often do.  We talk of friends and relatives, of news and memories.  This always gives Mom great pleasure, and it’s only after twilight falls and we exhaust these happy topics that she turns toward darker concerns.  Old age.  Recurrent bouts of illness.  And coming to terms with not being able to see faces anymore, recognizing those near her now by size, a characteristic walk, a familiar voice.

It’s medication time.  The nurse comes in.  Mom, now a pro at this, swallows all her nighttime pills with one big gulp and settles in for the evening.  Elizabeth wishes us a good night as she clears the dinner dishes.  After kindly asking if there’s anything else we need, she hurries home to her own family, and Mom and I are alone again in her room.

After a long pause, double-checking that the doorway is still empty, Mom leans closer and confides something that’s troubling her.  She hesitates.  “You know,” she whispers, “I don’t want to say anything to anybody, because it sounds…well, crazy…but I’ve been kind of…seeing things sometimes.”

Oh, God.  “Seeing things,” as we all know, is rarely a good thing.

I try to sound nonchalant.  “Really, Mom?  What kinds of things?”

“Shapes.  Bright fields of diamonds and colored filigree patterns.  Oh…and a girl’s face!  She wears the most beautiful old-fashioned bonnet!”

I sit transfixed by the coincidence.  At bedtime the night before, I had been reading a book by neurologist Dr. Oliver Sacks.  He described an exotic-sounding disorder with a unique assortment of odd hallucinations, and it’s uncanny how these visions coincide with Mom’s description.  It’s as if she has just read the same chapter, too.

I ask her for more details.  And as we talk on into the evening, she tells of fantastic flowers fading in and out of view.  Bright honeycomb-like hexagons creeping up the walls.  She has seen brilliant points of light, hundreds of them, scattered over the ceiling like great fields of stars.  Ornate filigrees which, she marveled, were much more detailed than anything she would ever have seen in real life.  And most peculiar of all, that strange girl.  Just a floating head and face of a young woman with elaborate, ringleted hair and an amazing lace-filled Victorian hat.

Mom is very animated, clearly relieved to finally tell someone about this.  But she turns thoughtful for a few moments.  “I know they’re not real, but I see them so clearly.  I’m worried I might be losing my mind.”

I smile reassuringly, though I know she can’t see it.  “No Mom!  You’re not crazy!…but I think you might have Charles Bonnet syndrome.”

_____

Once you learn about this syndrome, “CBS,” it’s the crazy nature of its hallucinations that stick in your memory.  These strange visions were first noted in 1760 by Charles Bonnet, a Swiss naturalist.  He observed them in his elderly grandfather, a man suffering from failing eyesight but still quite mentally sound and able to describe his apparitions in detail.  Recognizing their probable connection, Bonnet was the first to record such a relationship between hallucinations and vision loss.  But it was largely forgotten in the literature, and it wasn’t until 1982, in the field of psychiatry rather than general medicine, that the syndrome’s name was officially coined.  And even today, many physicians and nurses are not well acquainted with its eccentric yet specific set of signs and symptoms, so consistent across those who experience them.

First, there are the so-called simple hallucinations.  These may manifest as spots of colored light, grids, mosaics, or other repeating geometric or ornamental patterns.  Most people with CBS will see at least one of this type at some point.  Others may see scraps of text, long strings of numbers, or nonsensical musical notation.  A smaller number of people will experience more complex hallucinations.  These can be of animals or scenery, but most frequently they involve people, or even just faces.  They are usually soundless and often dressed in elaborate garments and hats, like the one worn by the young girl my mother “sees.”  Adding to their eeriness, certain facial features may be very distorted or exaggerated, especially the eyes or teeth.  And if the hallucinator still has some remaining vision, these images can superimpose themselves onto the existing surroundings, creating a kind of virtual reality and a very confusing situation for the sufferer.

But perhaps the most striking thing about these images is their typical complexity.  They often have a level of detail much finer than we’re able to see in the real world.  It’s as if these visually impaired individuals have an “inner eye” that’s capable of perceiving much more extraordinary resolution than their “outer” ones ever could.  And this might not be far from the truth.

CBS’s unique phantasms are known as “visual release” hallucinations.  While the exact mechanism is not clearly understood, they are thought to reflect the brain’s adjustment to lack of real-world input from the eyes.   They may represent our memory of primitive image components, building blocks for our recognition of forms, patterns, faces, and other complicated images.  It’s believed that a critical amount of vision might be needed to suppress activation of these images in the brain’s visual pathways.  Without this dampening, the raw neurological activity may be unmasked or released, so to speak, creating hallucinations.  Studies in the 1990’s determined that CBS hallucinations do indeed co-opt the same neural pathways we use to process what we see.  This is likely why they usually seem so vivid and real.

CBS can develop from a number of eye disorders such as glaucoma, cataracts, or often with macular degeneration, as in my mother’s case.  It’s been reported during short-term visual deprivation due to physical barriers, such as the application of temporary eye patches or other dressings after eye surgery.  It can even develop from the mechanical pressure of pituitary tumors on nearby optic nerves.

But it also sometimes results from damage to areas higher up the neurological pathway, all the way to the visual cortex in the rear of the brain, in the occipital lobe.  This area is involved in some cases of hallucinations, especially when it’s subjected to direct activity such as ongoing epileptic seizures.  CBS can also occur from a variety of conditions that impact blood flow in the region:  blockage caused by a clot, the inflammation of encephalitis, an occipital mass compressing the tissues.

The syndrome can develop at any age, though is most often seen in the elderly.  Its visions may occur only once as a single hallucinatory experience, or they can persist for years.  But for now, there is no cure for CBS.  Encouragingly, the symptoms have been responsive to a number of experimental medications, and the search continues for the most effective way to treat them.

Fortunately, those who experience these visions are usually fully aware that they aren’t real.  This is yet another clue that they are neurologic rather than psychiatric.  In fact, in addition to the other two cardinal symptoms of vision loss and recurrent hallucinations, this level of insight is one of the three basic criteria required to make a correct diagnosis of CBS.

But sadly, where there is this amount of insight, there’s bound to be fear for one’s mental health.  This worry is very common among CBS patients, and it can impact their willingness to report hallucinations, lest they be thought insane or demented.  By current estimates, it’s believed CBS affects somewhere from 10% to 40% of the elderly population who have visual loss.  But the actual number may be considerably higher because of this reluctance to report symptoms.

To make matters worse, recent surveys have shown a very low level of awareness of Charles Bonnet syndrome among patients with retinal disorders.  Many people will likely suffer in silence, afraid for their sanity but even more fearful of the doctor’s potential diagnosis.

It is precisely this kind of distress that makes it so important that medical staff, caretakers, and especially the patients themselves are educated about this disorder.  And if a patient does go on to develop hallucinations, kind reassurance that these strange visions are benign can go a long way to help soothe anxiety in someone already suffering from the devastating blow of permanent vision loss.  For now, compassion is the best CBS medicine we have to offer.

_____

Mom has lived with her hallucinations for many months now.  When she finally described them to her doctors, their oddness in the face of her otherwise clear mental status had them baffled.  But eventually, one late winter morning, a diagnosis was made.

That afternoon, I arrived just in time to see volunteers wheel her, beaming, down the hallway towards her room.  She loves Bingo, and thanks to the jumbo-sized numbers on the cards, she can still enjoy playing the game.  She was delighted at that day’s big winnings.

But this wasn’t the only reason she was happy.  After watching the nurse carefully lock away her Bingo loot, Mom turned to me excitedly.  “You won’t believe it,” she said.  “I saw the eye doctor this morning, and he said I have that Charles syndrome!  He knew right away!”

And with that, the diagnosis was official.

My mother gets some eccentric phantom visitors.  Bonnet Girl, as we jokingly call her, still arrives daily in her finest millinery.  She’s now accompanied by a new boyfriend, not quite so charming.  This scruffy guy has “one big ugly eye that sticks out,” and greeted Mom that morning in the activities room.  But later a very real — and thankfully, better looking — young man came to see her, too:  the ophthalmologist.  Having many CBS patients of his own, he spotted the peculiar signs and symptoms immediately.

For Grace, coping with end-stage macular degeneration is a constant challenge, to say the least.  Each day her vision seems worse, though doctors will see no further clinical change.  But Mom is determined to enjoy life as best she can.  Although sometimes exquisite, sometimes grotesque, she accepts her fantastic illusions for the harmless figments they are.  She returns, for awhile, to a world with clear faces and vibrant details.  And now that she has a name to call this illness, she takes comfort in knowing she’s not “crazy,” after all.

It’s just life with Charles.