January 26, 2022

Reversible Conditions That Could Be Mistaken For Dementia

Written by: Amanda Cheong, M.D.

If you search out dementia online, you’re likely to find that it is characterized by a “persistent and progressive deterioration of cognitive function.”[1] Persistent and progressive. In particular, those two words are bound to be frightening to just about anyone. It hits you like a speeding truck hanging on worn brakes. After all, dementia has no cure. Instead, it has a relatively poor prognosis, with 35% of those diagnosed passing on within the first year and 60% within the next five years.[1]


But what if it wasn’t dementia? What if it just looked like dementia?


What if it’s treatable?


Characteristics and evaluation of dementia


Cognitive decline in dementia usually means a set of behavioral changes-- sometimes they come quickly and sometimes insidiously. Often, these include memory loss, where they forget something that was said recently. They may get lost in places that used to be very familiar to them. They may leave their glasses or dentures in strange places like the fridge. You might find them in the middle of a task, having forgotten what they were doing just then. This may lead to frustration, aggression, and behavioral changes. Sometimes, they may have problems doing things they used to do, such as getting dressed for a party or preparing their food. At worst, they lose the ability to take care of themselves.[1]


Of course, just because you have these symptoms doesn’t mean it’s dementia. Who hasn’t lost a train of thought every once in a while?


A thorough clinical evaluation is necessary to determine whether someone has dementia or not. This would include a rather detailed interview with your healthcare provider-- and perhaps a referral to a specialist. They may let the patient answer a battery of tests, and they’re not graded, so don’t worry! And for these tests, it’s best not to coach them so the healthcare provider can get a clear picture of how things are.


Lastly, the doctor might request for laboratory tests to be done. They can range from a few simple ones, such as a complete blood count, to the more specific ones like thyroid function tests. Don’t be surprised when they request tests for sexually transmitted diseases-- as there is a number that can lay quiet for several years before spouting up neurologic symptoms. In some cases, a CT scan might even be done.


Reversible dementias


Altered mental status generally refers to the change in cognition or level of consciousness, as we have mentioned earlier. There are three common causes of altered mental status-- all of which are easy to remember since they start with the letter D: Dementia, Delirium, and Depression.[2]


Technically, dementia is characterized by something that is chronic or takes a long time to develop. Whereas delirium is considered an acute confusional state that comes and goes, often starting just a few days or weeks ago. However, the reality is that the lines blur when we discuss persistent delirium or reversible “dementia” and one may be mistaken for the other.[2


Delirium is also sometimes known as “potentially reversible dementia”-- which isn’t dementia but try saying “reversible conditions that mimic dementia” a couple of times. A study showed that out of 340 patients seen in a Behavioral Neurology Outpatient Unit, around 20% of the cases were found to have reversible causes.[3] The most common cause of these reversible dementias were head injuries, with alcohol as a close second.[3] The causes may differ depending on the country, with a study done in Brazil showing that infection was the predominant cause.[4]




Especially in the elderly, delirium may be triggered by several problems. In a 2017 study, in 3 months, 60 elderly patients were hospitalized for delirium with infection as the cause. Among the different infections, 55% had pneumonia and 27% had urinary tract infections. The majority (73.3%) were diagnosed with the kind of infection that was already considered sepsis.[5


Infections are a bit tricky in the elderly. Sometimes it’s hard for them to communicate that there’s something wrong. Other times they might not notice it. Doubly challenging is that older individuals are more likely to catch these infections. Their immune system may not be as strong as it used to be. They are more likely to have a urinary catheter which predisposes them to a urinary tract infection. Aspiration pneumonia may also happen when food enters the wrong track, as may happen with older adults who have less control of their laryngeal muscles. When in doubt, it may be worth seeing if this is an infection in hiding.[3]




Earlier, we mentioned that doctors might take a patient’s thyroid hormone levels when evaluating dementia. This is because low thyroid hormone levels or hypothyroidism can cause cognitive impairments similar to dementia. They can manifest as memory loss, general sluggishness, a flitting attention span, and depressed or apathetic mood.[6]


The good news is that these cognitive symptoms are largely reversible with the proper thyroid hormone treatment.[6] However, it is also important to note that thyroid dysfunctions are associated with a very specific kind of dementia-- Alzheimer’s dementia. While current data cannot say which causes what, what we have points to a relationship between the two.[7] So someone can have thyroid dysfunctions while having a kind of dementia. This is something best discussed with your healthcare practitioner.


Other conditions


While we have mentioned the most common conditions that can mimic dementia, there are still others out there. Wernicke encephalopathy, which is also characterized by confusion and altered mental status, may look like dementia. While this is often found in alcoholics, this disease is due to a vitamin deficiency compared to the toxic effects of alcohol itself and, thus, reversible.[8]


Not to be confused with hepatic encephalopathy, which is impaired brain function due to an alcohol-damaged liver--- too damaged to process the ammonia that a normal person’s body can go through. This is sort of reversible as the cognitive impairment can be remedied by supporting the clearance of ammonia. However, this will continue to be a problem unless the underlying liver damage is corrected.[9]


Indeed, several things can look like dementia. And this may not be the feared persistent and progressive deterioration, and we may still get our loved ones back cognitively.



  1. Emmady PD, Tadi P. Dementia. [Updated 2021 Nov 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557444/
  2. Gogia B, Fang X. Differentiating Delirium Versus Dementia in the Elderly. In: StatPearls. Treasure Island (FL): StatPearls Publishing; November 22, 2021.
  3. Bello VME, Schultz RR. Prevalence of treatable and reversible dementias: A study in a dementia outpatient clinic. Dement Neuropsychol. 2011;5(1):44-47. doi:10.1590/S1980-57642011DN05010008
  4. Takada LT, Caramelli P, Radanovic M, et al. Prevalence of potentially reversible dementias in a dementia outpatient clinic of a tertiary university-affiliated hospital in Brasil. Arq Neuropsiquiatr. 2003;61:925–929.
  5. Kuswardhani RAT, Sugi YS. Factors Related to the Severity of Delirium in the Elderly Patients With Infection. Gerontol Geriatr Med. 2017;3:2333721417739188. Published 2017 Nov 13. doi:10.1177/2333721417739188
  6. Samuels MH. Psychiatric and cognitive manifestations of hypothyroidism. Curr Opin Endocrinol Diabetes Obes. 2014;21(5):377-383. doi:10.1097/MED.0000000000000089
  7. Figueroa PBS, Ferreira AFF, Britto LR, Doussoulin AP, Torrão ADS. Association between thyroid function and Alzheimer's disease: A systematic review. Metab Brain Dis. 2021;36(7):1523-1543. doi:10.1007/s11011-021-00760-1
  8. Vasan S, Kumar A. Wernicke Encephalopathy. [Updated 2021 Aug 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470344/
  9. Ferenci P. Hepatic encephalopathy. Gastroenterol Rep (Oxf). 2017;5(2):138-147. doi:10.1093/gastro/gox013
Article written by Amanda Cheong, M.D.
Dr. Amanda Cheong spent her formative medical years within the walls of the Philippine General Hospital, a high-volume tertiary institution built to serve the underserved. After graduating with a degree in medicine, she went on to write, edit, and compile healthcare stories from the start of the COVID-19 pandemic for an online anthology. Currently, she is involved in medical research as well as volunteer telemedicine consults. She enjoys writing fiction on the side when she’s not tending to her plants and three pet turtles.

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