Even though I’m a doctor, I dismissed my forgetfulness as just stress. But then it turned out to be something much more sinister

Like any GP, Dr Rob Lambourn spent most of his working day listening to his patients describe their symptoms as he tried to determine what was wrong with them.

But when it came to his own health, he may not always have been so diligent.

In fact, he dismissed his own symptoms, such as forgetfulness and loss of fine control over his fingers, until they came to a head one day at work — and he was later diagnosed with a rare neurological disorder that tragically shortened his life expectancy.

Rob, who had been a GP for 30 years, says: ‘In between patient visits, I suddenly had a funny turn of events.

‘My computer screen looked like it was crap – it was just a page of equations. But I had other patients to see, so I carried on and tried not to worry about it.

“Then I had to order a chest x-ray for someone over the phone. It’s a simple task and I’d done it countless times before, but I couldn’t remember how to do it.”

Rob, 64, runs the practice in Wooler, Northumberland, with his wife Liz, 50, who is also a GP. He called her from her room next door to help.

“I told Liz I couldn’t remember how to order an X-ray, which seemed strange,” Rob says.

‘She was immediately very concerned, because this was so unusual. She helped to order the scan, but insisted that I go to my own GP as soon as possible.’

Rob called his doctor after his morning surgery was over and told him what had happened.

“She thought the symptoms were similar to a mini stroke, which was very dramatic and worrying,” Rob recalls.

He was referred to a stroke clinic, where he underwent a CT and MRI scan the next day, but these ruled it out.

Later examination by a neurologist revealed that Rob had corticobasal degeneration (CBD), a rare form of dementia that develops slowly and affects movement, speech, swallowing and memory.

Heartbreakingly, most patients have a life expectancy of just four years after diagnosis, as the brain and body slowly but surely stop functioning normally, leading to complications that can be fatal.

The rate at which CBD develops can vary from patient to patient, but on average it takes about three years for patients to be diagnosed. This is because changes can be so gradual and are often mistaken for other neurological problems, such as stroke, Parkinson’s disease, or other forms of dementia, such as Alzheimer’s.

Looking back, Rob says he should have paid attention to the early symptoms at least 12 months earlier.

“I developed a weakness in my right hand, which I noticed when doing fine motor skills,” says Rob, a father of four who lives in Foulden, a village near Berwick-upon-Tweed.

‘I noticed it every time I moved my computer mouse at work.

‘I also had trouble playing my mandolin in the ceilidh band I was in for 26 years. Suddenly I couldn’t reach all the strings with my fingers.

‘But I blamed my increasing workload when Covid hit, or other things, instead of examining why I was struggling with tasks I normally did instinctively.

“I never thought it would be anything serious, so I just carried on and didn’t make a big deal about it.”

But he adds: ‘The consultant said I probably started developing CBD about a year earlier. When I described my right hand not working as well as it used to, I didn’t realise it was an early symptom.

‘I think that’s very typical of doctors: you often ignore your own symptoms, even though you listen to your patients’ symptoms every day and investigate what’s behind those symptoms.’

CBD is thought to affect about six in every 100,000 people.

But this could be a gross underestimate, says James Rowe, professor of cognitive neurology at the University of Cambridge.

“CBD affects far more people than are currently diagnosed. For every person living with CBD, there is someone with symptoms who has not yet been diagnosed,” he says.

“In addition, there are people for whom CBD mimics more common neurological problems, such as Alzheimer’s, and in these cases the diagnosis may be incorrect.”

He believes there is a link between CBD and Alzheimer’s, not least because both conditions appear to be caused by damage to brain cells from the build-up of a naturally occurring protein called tau.

In most people, tau breaks down and doesn’t pose a problem, but in people with CBD and Alzheimer’s (along with another protein called amyloid), it can clump together and form plaques. These plaques are thought to gradually slow down the brain and block the nerve signals needed to keep the body functioning normally.

In people who use CBD, tau accumulates on the surface of the brain (responsible for memory, learning, problem solving, and emotions) and in a deep part of the brain called the basal ganglia, which is essential for speech and movement.

In Alzheimer’s, however, the damage is most often in the entorhinal cortex and hippocampus, parts of the brain responsible for language and how a person behaves socially. However, these symptoms are not always easy to distinguish, and the conditions can present very similarly.

Dr Boyd Ghosh, a neurologist at University Hospital Southampton, explains: ‘Normally the body uses the protein tau to transport nutrients up and down the nerves.

‘But in people with CBD, for unknown reasons, tau is folded in an abnormal way, causing it to function less well and causing these proteins to clump together.

“They essentially block things, causing the cells in the brain to die. It’s this neurodegeneration that causes CBD symptoms and causes patients to die earlier than normal.”

Normally, CBD first manifests as movement problems in one arm or one leg, he explains.

‘The arm or leg doesn’t do what you want it to do, so the hands can’t do a simple task that requires fine motor skills, such as doing up buttons.

‘Some people with CBD may feel like their limb has become alienated from them and experience what is called ‘alien limb syndrome’, where their hand makes involuntary movements.

‘They may experience tremors, their balance may be disturbed and their speech may become unclear.

“These symptoms are very similar to many other neurological problems, so you can see why it can be misdiagnosed,” Dr. Ghosh said.

Not only can it be mistaken for other forms of dementia, the early symptoms of CBD can also mimic those of Parkinson’s disease, which affects 153,000 people in the UK.

“There is no diagnostic test for CBD,” Dr. Ghosh explains.

‘Instead, we can look at the way they move their hands, because they may have difficulty with a certain movement.

‘Even if the patient does not respond to dopamine drugs [those diagnosed with Parkinson’s disease have a reduction of this chemical in the brain] then we would think they have CBD. But it could be a process of elimination, which could also delay diagnosis.’

Dr Ghosh adds: ‘People with CBD are then treated based on their symptoms. For example, if someone has difficulty swallowing, we look at ways to put thickeners in their drinks so that they swallow liquids more slowly.

‘The problem is that by the time CBD is diagnosed, there has already been a significant amount of damage done to the cells in the brain, meaning that by the time we figure out what to treat, the disease is already firmly in its grasp.

‘But we hope that, just like with Alzheimer’s research, there will also be a breakthrough with CBD.’

The increased research interest in CBD and related conditions led to the PROSPECT-M-UK study, which was established nine years ago.

Using MRI scans, blood samples, spinal fluid, detailed questionnaires and clinical assessments, the disease progression was monitored in about 1,000 people, including Rob.

About 100 volunteers who took part in the study donated their brains for medical research after their death.

Because tau is so small, it is not visible on any scan. It is only visible on brain samples when it is marked with a special dye.

In July last year, £1.4 million in funding was announced for a new phase of research, with a new study called ExPRESS to better map CBD in the brain.

“At ExPRESS the emphasis is on studying these diseases in the first year of the patient’s life, so that no time is wasted,” said Professor Rowe, one of the project’s investigators.

‘If a doctor suspects that a patient has it, he or she is immediately referred to a specialist. This prevents the boat from being missed because a correct diagnosis has not been made for years.

‘If we could treat patients when their symptoms are interfering with their daily lives, rather than when they are causing serious disability, that could make their quality of life much better in the long run.’

Rebecca Packwood, CEO of PSP Association, which provides support to patients with CBD and similar conditions, said: ‘Delays in diagnosis are common for people living with CBD, with one in three people taking over a year to be referred by their GP to a neurologist and it can take up to three years to get an accurate diagnosis.’

For Rob, who counts himself lucky to have been diagnosed relatively early, it was a life-changing event in many ways.

‘Liz and I wanted to keep working until I was 65 and then we wanted to go to New Zealand for a short period to work there.

‘But that was no longer possible, because I immediately went on sick leave and retired for medical reasons, exactly one year after the diagnosis in July 2022.

“I try to do everything I can to slow down the progression,” he says.

‘I take a five-mile walk or bike ride every day, do agility exercises, such as passing a coin between my fingers, and work on my balance.

‘I also do a Sudoku every day and so far my memory seems fine, although I sometimes struggle to find the right word.’

In August 2023, Rob started taking the drug co-careldopa for Parkinson’s disease, which can help with tremors and movement problems.

“It seems that taking this medication has slowed the progression of my disease and will allow me to do what I enjoy for a few more years,” said Rob.

“I had to stop working, but I would find it even more frustrating if I had to stop riding my bike, playing the mandolin or cooking with my family. I just want to keep doing those things for as long as possible.”

For more information please contact: pspassociation.org.uk