Olfaction and Cognitive Impairment

Comprehensive_List_of_Relevant_Pathways_for_the_Olfactory_System

Comprehensive List of Relevant Pathways for the Olfactory System by XenusG (CCBY 3.0)

I came across this paper (via the Alzforum) in which the researchers compared people with mild cognitive impairment (amnestic and non-amnestic), Alzheimer’s Type Dementia (DAT) and subjective cognitive impairment. The researchers found that people with amnestic mild cognitive impairment and DAT were less able to detect smells than the other participants. These findings replicated those from other studies and suggest that the olfactory apparatus can be a marker of the pathology leading to DAT.

Just to unpick this a bit further the rationale would be as follows. The olfactory apparatus is directly connected to the limbic system which also includes the hippocampi which are the key memory structures implicated in DAT. Amnestic MCI can be a precursor (although not invariably) to DAT and so both Amnestic MCI and DAT may share common pathological mechanisms.

Thus if the limbic system is affected by this pathology then not only will it affect memory but also olfaction (smell). Of course this is an oversimplified explanation. For instance there is no reason to suppose that all components of the Limbic system will be similarly affected by the same pathology. Regardless of the aetiology these findings do however suggest that there is a correlation between the sense of smell and the cognitive difficulties seen in amnestic MCI and also in DAT.

Index: There are indices for the TAWOP site here and here

Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link.

TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link.

Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk.

Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

Conflicts of Interest: *For potential conflicts of interest please see the About section

 

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s