Forgetting a name, misplacing the phone or struggling to recall a word can happen from time to time. It becomes more concerning when these lapses are no longer occasional and start changing the way a person functions.
The timeline matters too. A memory problem that becomes noticeably worse over a few weeks or months is different from the occasional forgetfulness many people experience with age. When the change is rapid, it deserves a closer look rather than being dismissed as ageing.
Other signs
Memory loss rarely occurs in isolation when there is an underlying neurological problem. Families may notice difficulty navigating familiar places, confusion, personality changes, unusual fearfulness or irritability, disturbed sleep, or difficulty carrying out tasks that were once routine.
I saw this pattern in a 61-year-old woman who had been diagnosed with neurodegenerative dementia while living abroad. Her memory problems and difficulty with visual-spatial tasks had developed over roughly two months. Around the same time, she became increasingly fearful and irritable and began experiencing several sleepless nights.
The speed of this change raised an important question: was this really a conventional neurodegenerative dementia?
When she came to India for a second opinion, we investigated further. Her brain MRI was normal, but because the symptoms were progressing rapidly, an autoimmune evaluation was undertaken. An unclassified neuronal antibody was detected. Further investigations, including an FDG PET scan of the brain, supported the possibility of autoimmune encephalitis.
This distinction was important because autoimmune encephalitis can sometimes produce symptoms that resemble dementia, including memory problems, confusion and behavioural changes. Unlike many neurodegenerative conditions, some forms of autoimmune encephalitis can respond to treatment.
Recovery can be a clue too
The patient was treated with immunotherapy, including steroids, intravenous immunoglobulin (IVIG) and later rituximab. Her recovery was gradual rather than immediate.
She began regaining her orientation to time, place and person. Her visual-spatial difficulties resolved, her memory disturbances reduced and her earlier personality returned. After around one-and-a-half years of follow-up, she had returned close to her previous cognitive functioning and was preparing to travel back abroad with her husband.
Her case highlights an important point: a diagnosis of dementia should be based on the complete clinical picture, not simply on the presence of memory loss.
When to seek help
There is no need to panic over every forgotten name or misplaced object. What matters is a clear change from a person's usual abilities.
Some signs deserve medical attention, particularly when they appear together:
Memory or cognitive problems worsening noticeably over weeks or a few months
Getting lost or struggling to navigate familiar surroundings
Sudden changes in personality or behaviour
New confusion or disorientation
Significant sleep disturbance accompanying cognitive changes
Difficulty performing familiar everyday activities
Seizures or other new neurological symptoms
The first step is to establish what has changed, when it began and how quickly it has progressed. A detailed history, neurological examination and targeted investigations can help identify the cause.
Ageing isn’t the explanation
Ageing and dementia are not interchangeable terms. Occasional forgetfulness can occur with age, but a sudden or rapidly progressive change in memory and behaviour deserves attention.
For families, the most useful thing to remember is simple: don't just ask what has been forgotten; ask how quickly the change happened.
That timeline can sometimes be the clue that prompts a wider evaluation, uncovers a treatable cause and changes the course of a patient's illness.
(Dr. Sheetal Goyal, Consultant Neurologist, Wockhardt Hospitals Mumbai Central)
