Olfactory Nerve.pptx ucd Dr samina malik

Physio olfactory

1. OLFACTORY NERVE

2. Introduction First cranial nerve Sensory Nerve used for smell

3. Testing of the function Use common odours- coffee, lemon, peppermint, soap etc NEVER USE IRRITANT ODOURS- such as ammonia, as it stimulates the V th nerve instead of I cr n Make sure that nasal passages are open and pt doesn ’ t have local nasal pathology Patient must close his eyes and asked to smell through one nostril after another Points to note- Whether he can detect any odour/not Whether he can identify the correct odour Is the intensity symmetrical on both sides

4. Perception more important than identification Perception indicates continuity of olfactory pathways Identification indicates intact cortical function as well Appreciation of presence of smell is enough for exclusion of anosmia.

5. Olfactory abnormalities Terminologies used Anosmia - Absence of smell sensation Hyposmia - Decreased sensation Hyperosmia - Overly acute sense of smell Dysosmia – Impairment or defect in sense of smell Olfactory agnosia - Inability to identify detected odours

6. Applied aspect History- Enquire about Past head injury Smoking Recent URTI Systemic illness Toxins/medications/illicit drugs Most common causes- URI Trauma Idiopathic

7. Examination Sr. No. The Candidate 1 Introduces himself/herself to the Subject & Asks him to sit comfortably. 2 Explains the procedure and seeks consent 3 Checks for the patency of each nostril separately by asking the subject close/occlude one nostril and to blow air out the other. 4 Asks the subject to close his eyes and keep them closed throughout the procedure. 5 Asks the subject to occlude one of his nostrils. 6 Asks him to smell of the test substance and name it. 7 Repeats the Procedure with different substances. 8 Repeats the Procedure on the other nostril. 9 Reports the Findings to the Examiner Verbally. 10 Thanks the Subject at the end.

8. Thank you