Posterior Cortical Atrophy
Alan Hope, Consultant Anaesthetist (retired).
Posterior Cortical Atrophy, or Benson's Syndrome, is an uncommon (4% of dementias) Alzheimer's process that starts at the back-right-hand side of the brain and affects relatively younger people (maybe mid 50s).
Being posterior many aspects of complex visual processing are affected early on.
Judging distances and spatial awareness become progressively impaired.
Sufferers report difficulty with numeracy, reading and writing, memory loss, various dyspraxias, and confusion. I live with, and care for, my wife who is a PCA sufferer.
Diagnosis
For us this was relatively quick. It involved excluding alternative diseases then confirming the suspected diagnosis. We had assumed that Debbie's brain fog and loss of numerical ability were the result of a severe bout of Covid, ie long Covid. However, the first sign that something else was going on was a visual field defect which was picked up by our optician. This defect is called a homonymous quantrantanopia. The key word here is "homonymous" which means it affects the same visual outlook in each eye. This pattern immediately places the cause in the brain, behind the eyes and optic nerves.
The differential diagnosis includes stroke, which may be treatable if you move quickly, so Debbie had a contrast-enhanced CT scan the same day. In our case this showed no stroke. Which started a complex diagnostic sequence involving multiple medical specialists (I had never heard of neuro-ophthalmologists: they're a thing). This included MRI and CT scans, and a case-conference: a long multi-specialty review and discussion of every nuance of her case.
A sample of her CSF was sent to London for analysis of tau and amyloid protein ratios. This confirmed a tau-opathy (an Alzheimer's-type process) which defined the appropriate treatment and the likely future Debbie faces. At this point the various medical specialties dropped out, ongoing management being coordinated by a dementia consultant.
Symptoms
These have been a journey of discovery. Many of the symptoms I list here, in detail, are to be expected given the areas of the brain affected. But what gradually became clear was how these quickly develop beyond a level which is mild, and awkward, to being crippling. Each of these symptoms disrupt previously routine parts of normal life. The cumulative effect of these, over a relatively short period of time, render a sufferer completely dependent on their carer. This is psychologically crushing and depression is both common and completely understandable.
We were pretty much left to assess the various symptoms ourselves, as they happened, and develop our own strategies for coping with them as they became progressively more severe. As you will see, at various times this put considerable stress on our relationship.
PCA clobbers you with a number of dyspraxias (clumsinesses). In Debbie's case these were:
Dyscalculia
An inability to do even very simple arithmetic was a significant early feature. This is staggeringly restrictive. Cooking involves following a recipe and calculating weights, volumes, timing, and temperature settings. This quickly becomes impossible. Tracking calendar dates, and simply telling the time, soon makes no sense at all. Working out how long to wait before a TV program comes on becomes impossible.
Managing cash became an issue. Calculating change, or assessing discounts, quickly became impossible. Calculators don't help, they're confusing. Shopping becomes impossible. My wife ran a school bookshop for many years and this was the immediate reason she had to give that up.
To our frustration it proved impossible to relearn basic arithmetic. We got primary-school maths books (aged 4-5), put in significant effort, and got nowhere. This impairment, like all the others, gets worse faster than you can relearn.
Dysgraphia
An inability to write which includes signing your own name. Debbie ended up with a revised signature that was just 3 rather shaky capital letters. This made signed documents legally valid if her signature was witnessed.
But it also prevents her from writing a shopping list, a message on a card, an address, keeping a diary, or filling in events in a calendar (see also dyscalculia above). Some of these can be done using an App. But typing on a phone becomes a slow chore, and voice-input is unfamiliar and difficult.
Left hemi-neglect
This is common in PCA and leads to a variety of problems. These include...
Visual impairment
Debbie now has a widespread left-sided visual field impairment. Being part of the hemi-neglect this is not actually a blind spot but involves objects and movement on Debbie's left being seen but not registering properly. It's impaired visual processing. And I get the impression her world is darker. She has small pupils, peers noticably and particularly struggles to find her way in dim light.
Difficulty walking
The left visual defect mean that broken ground is difficult to navigate. Debbie is now cautious, slow, and needs assistance much of the time. Balance is impaired, and she lives in fear of a fall particularly on stairs.
Right, Left
Dressing always involves assistance because getting any right/left correct is difficult. An item of clothing that is partly inside-out may prove impossible to untangle. Debbie often fails to put her left arm in her sleeve. Tieing shoelaces is impossible. We experimented with different bra-fastening types, but with assistance a standard M&S bra is as good as front-fasteners or sports-style.
Difficulty Eating & Drinking
The associated impaired hand-eye coordination makes familiar activities such as using a knife and fork confusing and difficult. A spoon is better. It may be impossible to avoid spilling coffee from a cup and a three-quarters full cup becomes safest - when we're out I often drink the top half-inch. Debbie tends to push food off the left side of her plate. Low-sided pasta-bowls don't help, she can't manage cutlery in those.
Internal maps
It is second nature to generate a quick map in your head. Say you go to the toilets in a restaurant—without thinking you easily make your way back to the table. Sufferers quickly find this difficult. The panic and embarrassment at feeling lost in a public space adds to feelings of dependance and "being a nuisance". This is now Debbie's every day experience. The world is a confusing place when everything to your left feels unfamiliar.
Conversation
Thankfully Debbie's ability to listen to fast conversation is unimpaired, complex concepts are easily understood, and her responses (including laughter) are immediate and appropriate. In short, she remains a good listener and is easy to talk to.
But she now has considerable difficulty expressing herself, starting with the basic concepts and ideas involved in gathering her thoughts together. She has a minor degree of stumbling over words, but a very noticable loss of spontaneity, of generating and expressing suggestions or opinions on anything outwith the immediate environment.
Paranoia
This was unexpected. False and upsetting memories began to regularly intrude in our lives. These are common and the general advice is to ignore them and not to challenge them. But where they involve bitter accusations of damaging or unfaithful behaviour it is impossible to passively accept guilt. We end up, repeatedly and calmly, reviewing the reality of these accusations—in detail. Curiously, and perhaps reassuringly, these episodes are completely forgotten just a few hours afterwards. But they always recur and the false-events are both detailed and exactly the same each time.
I noticed that Debbie was icy-cold and tremulous during these, making me wonder if they had a cerebro-vascular cause, ie were a form of migraine. I guess it's possible.
If Debbie is left alone for a few hours these delusions are more likely to occur. Also during the night. Both of us are distressed during these episodes, they are for us perhaps the worst part of the disease progression.
Loss of memory
Initially this was mild, but now, a year or so on, this is a real problem. All Debbie's yesterdays are now blurry and hard to remember. We still manage to watch Netflix box sets, but it's gradually becoming obvious that Debbie simply enjoys the fact that I enjoy these, and gets less out of them herself. She has always read, but now that her memory is worse, she reads less often, preferring just to sit and stare into space. Debbie now initiates very little conversation beyond the immediate present, "that's a nice sky". I guess if you can remember very little, there is nothing to start a conversation about. And she never suggests plans for the future, trips, what to eat, visiting friends, holidays. It's all now initiated by me. Heartbreaking.
Our relationship
As a settled married couple since 1990 we start in a good place with regard to relationships. However, a progressive debilitating disease like this is a daily stressor, and has needed effort from us both in an attempt to keep ourselves happy.
I have gradually learned to live with a wife who had all the above issues, with no prospect of improvement, and who was aware of her own prognosis. It may sound simple, but continually telling her that I loved her, hugging her, and holding her hand when we were out, along with constant reassurance that I wasn't going to abandon her, that we were together come-what-may, made a huge difference.
I also had to be sure to say things like, "I'm going upstairs to do some (hobby stuff), I'd love you to come and be with me, so if you get bored with reading / listening please join me." Otherwise I risked going back downstairs after a couple of hours to find her upset, tearful and accusative.
The hardest thing for me was to suppress my frustration when she seemed unduly slow and clumsy yet dismissed any attempt at assistance or advice. I would say as she began to tip her cup to one side, "be careful or you'll spill your coffee". She would immediately retort, irritated, "I am being careful", and then spill it on herself. I had to learn to be infinitely understanding. I like to think I'm getting closer to that now, but I'm only human.
I now wash Debbie's hair. It's easy for me to do, feels luxurious for her, and gives us happy chatting time.
And we need more visitors. Debbie loves having people around, the chat, memories, the food, little day-trips. I now have a longish list of names on a whiteboard in the kitchen and we'll be working our way through these.
Plans
Although walking is more difficult, and sadly our hill-climbing days are probably over, we will have more long-weekends away and simply walk easier paths. Easy paths and National Trust gardens are our thing now. Debbie now has, and needs, some structure in her week. Friday mornings are her regular exercise class and she looks forward to that.
There's Scotstoun Leisure Centre round the corner so I'm looking at some early-morning swimming for myself. I also need regular exercise and I'm currently not getting it. An hour or so should be possible. Swimming isn't Debbie's thing at all, she hates water near her eyes and the faff of getting changed is an annoyance to someone who needs assisted dressing.
Treatment
Donezepil (or similar) may cause a slight improvement in symptoms. That's it for specific meds. In terms of managing symptoms, antidepressants are often used. It's hard to see these helping much if the root cause of the depression remains at the forefront of your mind 24/7. We can access practical advice from various NHS sources.
Otherwise, we feel very much on our own, and we are already cautiously discussing plans for a variety of futures.
Also the internet, daily, teases "astonishing breakthroughs" in dementia treatment by the ubiquitous "scientists". The "retired-doctor-cynic" in me sees the staggering amount of donated money available for dementia research and suspects it will all get spent whether usefully or not.
Disease progression
October 2025
Having noticed Debbie increasingly struggling to read her Kindle we did some informal eye tests. She is close to having tunnel vision, now saying that my face is difficult to see even when slightly off centre. This suggests disease spread to both sides of the back of her brain. All the other symptoms seem slightly worse. We are happy enough, but I can't leave her alone for more than an hour or so—and that may have to stop soon.
January 2026
Debbie now can't read which is hugely frustrating for her, and she's very down. Reading has been replaced by TV documentaries and crime series, which she enjoys. She is always asking, "what can I do, I want to be useful", and I find small tasks for her, but she struggles with them all and gets frustrated. She's essentially with me all the time now. I can't leave her alone at all. Her memory is much worse, she forgets what we've just talked about, and often can't remember what day it is. Her walking is OK on a good surface, but she needs good light. Her episodes of paranoia have stopped, thankfully, and we are both much happier as a result. We are worried that she'll be functionally blind soon. This is a truly appalling disease.