Neurological Examination Of Olfaction And Gustation

Question 1

How is olfactory testing done?

Answer 1

• Olfactory testing:
• Not routinely carried out
• Ensure use of well-known, non-noxious stimuli (coffee, cloves, vanilla, soap, etc.)
• Patient asked to occlude one of their nostrils with their finger
• Examiner presents a container with olfactory stimulus
• Repeated on the other side

Question 2

What are the common causes of asomnia and hyposomnia?

Answer 2

• Common causes of anosmia and hyposmia:

* Allergic rhinitis, common cold, smoking, head trauma

Question 3

What are the gustatory testing methods?

Answer 3

Gustatory testing:
• Usually limited to CN VII, innervating the anterior part
of the tongue
• Cotton buds dipped in salt solutions, lemon juice for sour, sugar solutions, and tonic water for bitter
• Mouth needs to be rinsed between individual applications
• Each side of the tongue tested separately

Question 4

What are the common causes of aguesia and hypoguesia?

Answer 4

• Common causes of ageusia and hypogeusia:
• Ageusia is rare, due to redundancy and central divergence of taste pathways. Bell’s palsy can result in unilateral ageusia of the anterior tongue.
• Hypogeusia is more frequent. Tobacco use is a common cause.

Question 5

What’s the clinical correlation of PICA syndrome and Ageusia?

Answer 5

Gustatory nucleus→ Ipsilateral loss of taste

ALS→Contralateral loss of body pain and temperature

Spinal trigeminal nucleus and tract→Ipsilateral loss of facial pain and temperature

Vestibular nuclei→ pathological nystagmus

Question 6

What is asomnia?

Answer 6

• Anosmia (total loss of smell function) may result from the compression of the olfactory tract by tumours, especially meningiomas.

Question 7

What is hyposomnia?

Answer 7

Hyposmia (decreased smell function) is four times more common than hypogeusia (decreased taste function), although patients commonly complain they cannot taste, when, in reality, they mean they do not obtain the adequate flavour from food.

Question 8

What is what’s the effect of epileptic seizures in the vicinity of uncus?

Answer 8

• A patient suffering from epileptic seizures originating in the vicinity of the uncus may sometimes experience olfactory hallucinations, like the experience of a pungent, unpleasant smell, in the absence of odorants that would explain such smell sensations.

Question 9

How does COVID-19 affect chemical sense?

Answer 9

• In the list of clinical symptoms of COVID-19, a sudden loss of sense of smell and taste has been identified.
• This can be found even in the absence of the “usual symptoms” such as fever, cough, respiratory failure.
• A recent study on around 4,000 participants from more than 40 countries confirms that COVID-19 broadly impacts chemosensory function across multiple sensory modalities