Olfaction and Taste Flashcards
What is anosmia?
Loss of smell
What is hyposmia, or olfactory hypoesthesia?
Decrease sensitivity to odorants
What can cause olfactory hallucinations?
Lesions of the parahippocampal region
What is Foster-Kennedy Syndrome?
Multiple sensory and motor disturbances
blindness/scotoma (ipsilateral), optic atrophy (ipsilateral), anosmia, and contralateral papilledema. Caused by Meningioma of olfactory groove, compressing olfactory tract and optic nerve.
What is Kallmann’s Syndrome?
Genetic conditions resulting in failure to commence puberty which is characterized by hypogonadism, anosmia, or hyposmia
What is UPSIT?
Me studying for my 5th exam in 3 weeks.
UPenn standardized test for olfaction via scratch and sniff odor strips.
How does capsaicin act as an analgesic and anti-inflammatory?
Activates C fibers (pain) via opening the VR-1 ion channel (hyperalgesia); however, repeated exposure leads to desensitization of pain fibers (analgesia)
What are nasal polyps?
Noncancerous growths of nasal cavity or within sinuses resulting from inflamed mucous membranes / allergic reactions
What can nasal polyps cause?
Obstruction of nasal cavities or extend into the nares. Associated with anosmia, hyposmia, or hyperosmia.
Rhinitis / sinusitis commonly result in:
Loss of olfaction due to blocked access of odorants to olfactory epithelium. Some viruses can permanently cause damage.
What is treatment for rhinitis / sinusitis?
Anti-inflammatories; attenuate symptoms. This suggests edema of olfactory epithelium as the problem.
Trauma involving the olfactory tract / bulb can cause:
damage of the central processes of the olfactory neurons or the olfactory receptor axons passing through the cribriform plate (olfactory fila) –> temporary/permanent loss of smell
Trauma involving laceration of the dura and fracturing the cribriform plate can cause CSF to leak into the paranasal sinuses and through the nose. This is called ______.
Rhinorrhea
__________ can involve CSF rhinorrhea, damage the _______, and lead to _______.
Anterior skull base fractures; olfactory nerve; meningitis
In trauma of the anterior skull, a lack of subconjunctival hemorrhage can rule out _________
direct ocular trauma (damage to anterior venous sinuses)
Neuroblastomas, arising from _______, can impair olfaction. Clinical signs are:
Neuroepithelial cells (called Esthesioneuroblastoma).
- Chronic epistaxis
- Nasal obstruction
Olfactory groove meningiomas arise from _______ and cause _______.
arachnoid cells along cribriform plate; Foster-Kennedy Syndrome.
Further extension can cause extraocular paralysis and facial numbness
What is specific anosmia?
Condition in which an individual cannot perceive the odor of a particular compound or class of compounds, caused by autosomal recessive trait causing absence of specific odorant receptor.
What is hyperosmia?
Increased olfactory acuity in conjunction with migraine and hysteria; also in substance abuse cases.
Loss of olfaction can cause:
Loss or alteration of taste
If smell detection can occur, this indicates that…
the peripheral nerve/pathway is intact
If smell identification can occur, this indicates that…
cortical function is intact
What is olfactory agnosia?
Aware of smell, but can’t recall the name
What does unilateral anosmia suggest?
Nasal cavity disease or tumor-associated compression injury
What does bilateral anosmia suggest?
Head injury or common cold
Olfaction decreases gradually with age.
The patient will probably fail to notice.
Neurodegenerative diseases, like Parkinson’s, Alzheimer’s, and Huntington’s, produce ________
marked reduction in olfaction early in the disease (central processes affected)
What are some psychiatric disorders associated with olfaction?
Psychosis, depression, epilepsy, and Korsakoff syndrome
What is dysosmia (or parosmia)?
Distortion of smell experience
What is olfactory hallucination / phantosmia?
Perception of smell without odor present
Psychiatric olfactory anomalies likely result from:
Abnormal sequences of neuronal activity from an irritative lesion in the:
- anterior medial temporal lobe
- amygdala
- hippocampus
- medial dorsal thalamic nucleus
What are uncinate fits?
Epilepsy that specifically can result from focal seizure of uncal region
Uncinate fits can cause:
disagreeable olfactory auras (cacosmia)
Who has uncinate fits?
People with seizure disorders, tumors, vascular disorders, head trauma, infection, drug use, substance withdrawal
What is the extralingual taste buds reflex?
Stimulation of these taste buds (near larynx) can elicit a response to prevent accidental aspiration of ingested materials
What is ageusia?
Complete loss of taste (rare, due to large number of nerves relaying taste information to CNS and bilateral nature of the input)
Vestibular schwannoma can affect taste by…
Compression of chorda tympani (anterior 2/3). Also, pralysis ipsilateral facial mm., hyperacusia, impaired nasal, submandibular, sublingual, lacrimal gland secretion
Lesion distal to the geniculate ganglion…
Will probably not involve taste (chorda tympani has escaped compression)
What is hypogeusia?
Decreased sensitivity of taste (more common than absence)
What is dysgeusia (parageusia)?
Distortion of taste, due to trauma, Bell palsy, herpes simplex, drug use
Cystic fibrosis patients experience increased sensitivity of taste resulting from _______
hyperviscosity of saliva
What is cacogeusia?
Trigger of unpleasant taste sensation following focal seizure of taste processing centers within the brain
What causes gustatory hallucinations?
Rarer than olfactory, but elicited by electrical stimulation of frontal/parietal opercula, amygdala, hippocampus
