15.3 – Sensory Diseases, Disorders and Diagnostic Testing
Olfactory Diseases and Disorders
Anosmia
Blunt force trauma to the face, such as that common in many car accidents, can lead to the loss of the olfactory nerve, and subsequently, loss of the sense of smell. This condition is known as anosmia. When the frontal lobe of the brain moves relative to the ethmoid bone, the olfactory tract axons may be sheared apart. Professional fighters often experience anosmia because of repeated trauma to the face and head. In addition, certain pharmaceuticals, such as antibiotics, can cause anosmia by killing all the olfactory neurons at once. If no axons are in place within the olfactory nerve, then the axons from newly formed olfactory neurons have no guide to lead them to their connections within the olfactory bulb. There are temporary causes of anosmia, as well, such as those caused by inflammatory responses related to respiratory infections or allergies. Loss of the sense of smell can result in food tasting bland. A person with an impaired sense of smell may require additional spice and seasoning levels for food to be tasted. Anosmia may also be related to some presentations of mild depression because the loss of enjoyment of food may lead to a general sense of despair. The ability of olfactory neurons to replace themselves decreases with age, leading to age-related anosmia. This explains why some elderly people salt their food more than younger people. However, this increased sodium intake can increase blood volume and blood pressure, increasing the risk of cardiovascular diseases in the elderly (Betts, et al., 2013).
Ears, Nose, and Throat Diseases and Disorders
Otitis Media
Otitis Media is known as inflammation of the middle ear canal that involves the eardrum. It is commonly seen in younger children due to bacterial and viral infections. Symptoms include possible fever, cough and cold symptoms, hearing loss, irritability and otalgia. Treatment involves symptomatic control as well as antibiotic (Amoxicillin) use if necessary (Government of Canada, 2016). To learn more about otitis media, review this website by the Government of Canada [PDF].
Otitis Externa
Otitis Externa is inflammation of the external ear canal and is known as swimmer’s ear because it is associated with its exposure to water. Its clinical presentation and management are the same as otitis media (Piercefield et al., 2011). To learn more about otitis externa, review this website from the Centers for Disease Control and Prevention [New Tab].
Conductive Hearing Loss
Hearing loss occurs when something disrupts sound through the mid and outer ear, such as physical damage to the ear drum (perforation). Hearing loss can be managed with pharmacotherapy, surgery, or a combination of the two (Centers for Disease Control and Prevention, 2023).
Sensorineural Hearing Loss
This hearing loss results from damage to the neural structures. Tumors as well as exposure to loud noises (acute/chronic) can lead to this type of hearing loss (Centers for Disease Control and Prevention, 2023). To learn more about sensorineural hearing loss, review the Centers for Disease Control and Prevention’s web page about sensorineural hearing loss [New Tab].
Tinnitus
Tinnitus is a condition of ringing in the ears. It is due to inflammation of the middle ear. It is the first indicator of nerve damage, particularly in sensorineural hearing loss (National Library of Medicine, 2022). For more information, review this page on the role of inflammation in tinnitus [New Tab] from the National Library of Medicine.
Otosclerosis
This is hardening of the ear due to new bone formation of the inner ear ossicles. The etiology is idiopathic or may be hereditary. Clinical features are consistent with that of conductive hearing loss. Further management is required by an ENT surgeon (Veterans Affairs Canada, 2019). To learn more, visit the Veterans Affairs Canada web page on Otosclerosis [New Tab].
Rhinitis
Rhinitis is inflammation of the nasal cavity mucosal lining, which can lead to congestion and rhinorrhea (runny nose). The causes may be due to allergic reactions as well as viruses. Treatment regimens include symptomatic management, saline sprays, and oral antihistamines (Naclerio, Bachert, & Baraniuk, 2010). To learn more about rhinitis and other nasal conditions, please view Naclerio, Bachert, & Baraniuk’s article Pathophysiology of Nasal Congestion [New Tab].
Dacryostenosis
Also known as nasolacrimal obstruction, this is an obstruction of the nasolacrimal duct. It prevents tears from draining from the eyes into the ducts and thus individuals have excessive tearing. The etiology is congenital and is the result of the duct not forming properly. This condition is managed via observation, as it resolves overtime (usually after 1 year) (Merck Manual, 2024). To learn more, visit the Merck Manual’s web page about dacryostenosis [New Tab].
Eye Diseases and Disorders
Blindness
The term “blindness” may cover a broad spectrum of visual disabilities such as the inability to see because of injury, disease, or a congenital condition. The parameters for legal blindness are a visual field of 20 degrees or narrower and/or visual acuity is 20/200 or less in both eyes, even after correction. Many of the conditions described below can lead to visual disability, low vision, and legal blindness (Canadian National Institute for the Blind, n.d). To learn more about blindness, visit this website by the Canadian National Institute for the Blind [New Tab].
Cataract
A cataract is a clouding of the normally clear lens of your eye. For people who have cataracts, it may feel like they are looking through cloudy lenses or windows. The lens of the eye loses its flexibility due to the aging process, leading, in some cases, to senile cataracts. Infants are sometime born with congenital cataracts. Treatment usually involves surgery to remove the clouding of the lens (Mayo Clinic Staff, 2023). To learn more, visit the Mayo Clinic’s web page about cataracts [New Tab].
Conjunctivitis
This is a condition involving inflammation of the conjunctiva. Its common causes are due to allergens, chemicals, foreign objects, as well as bacterial and viral pathogens. The cause of conjunctivitis determines if it is transmissible from one individual to another. Pink eye caused by the adenovirus, for example, is highly contagious compared to pollen, which is not. Management involves treating the underlying cause of conjunctivitis (Centers for Disease Control and Prevention, 2019). To learn more about conjunctivitis, please visit the Centers for Disease Control and Prevention’s web page about conjunctivitis [New Tab].
Diabetic Retinopathy
This is a disease of the retina caused by diabetes mellitus. The retinal veins dilate, leading to swelling as fluid leaks from blood vessels into the retina. It is estimated that 20% of newly diagnosed diabetics suffer from diabetic retinopathy (American Optometric Association, 2020). To learn more, visit the American Optometric Association ‘s website on diabetic retinopathy [New Tab].
Glaucoma
This disease is part of a group of eye diseases which lead to progressive degeneration of the optic nerve. This, in turn, can lead to loss of nerve tissue that results in gradual irreversible vision loss and potential blindness if not detected and treated early. The most common form of glaucoma is primary open-angle glaucoma. This form is associated with elevated pressure caused by a backup of fluid in the eye (Canadian Association of Optometrists, n.d.). To learn more, visit the Canadian Association of Optometrists’ web page about glaucoma [New Tab].
Macular Degeneration/Age-related Macular Degeneration (AMD)
Progressive damage of a portion of the retina is known as the macula. Severe central vision is lost while peripheral vision is retained. This is the leading cause of blindness in people over the age of 55 years (Canadian Association of Optometrists, 2024). To learn more, visit the Canadian Association of Optometrists’ web page on AMD [New Tab].
Nystagmus
This is a condition whereby involuntary repetitive eye movements make it impossible to fixate on a single object. The condition is often referred to as dancing eyes (Dubow, 2020). To learn more about nystagmus, view this website from All About Vision [New Tab].
Retinal Detachment
According to the Eye Physicians & Surgeons of Ontario, this condition occurs when the retina gets pulled away or separated from its normal position. Flashing lights, floaters, and what appears to be a grey curtain are all symptoms of a retinal tear, which can lead to a retinal detachment. An ophthalmologist is a retinal specialist who can repair the retinal detachment. If left untreated, a retinal detachment could lead to blindness (Canadian Ophthlamological Society, 2007). To learn more, visit the Canadian Ophthalmological Society’s brochure on Retinal Tear and Detachment [PDF].
Strabismus
This is a condition where the affected eye rotates due to mismatched eye coordination. Each eye is focused differently, as described in the conditions below:
- Estropia: the convergence of one or both eyes medially
- Extropia: the deviation of one eye laterally
- Hypertropia: the deviation of one eye superiorly
- Hypotropia: the deviation of one eye inferiorly
If not managed, the brain may reject input from one eye, resulting in vision loss of the respective eye (amblyopia). Amblyopia is a condition also known as lazy eye, which is caused when there is an imbalance of stimuli from the brain to the eyes (one eye receives more than the other). It usually occurs in childhood and requires early intervention to rectify this condition (Canadian Association of Optometrists, 2023). To learn more about strabismus, go to The Canadian Association of Optometrists’ page on the subject [New Tab].
Sensory Systems Terms in Use
Sensory System – Consultation Report Activity
Sensory System – Consultation Report (Text Version)
Use the words below to fill in the consultation report:
- eye
- halos
- acuity
- iris
- dilate
- ophthalmoscope
- cataracts
- subcapsular
- surgery
- intraocular
PATIENT NAME: Betty FOX
AGE: 72
SEX: Female
DOB: October 2
DATE OF CONSULTATION: August 5
CONSULTING PHYSICIAN: Brian Gates, MD, Ophthalmology
REASON FOR CONSULTATION: Cataracts
HISTORY: I saw Mrs. Fox, a 72-year-old, for her regular ______[Blank 1] examination. She has been wearing reading glasses for several years now but has noticed that she has been having trouble reading and has been seeing ______[Blank 2] around lights while driving at night.
PHYSICAL EXAMINATION: A visual ______[Blank 3] test was performed. I used a slit lamp to view the cornea, ______[Blank 4], lens, and the space between the iris and cornea. I detected tiny abnormalities. I administered drops to ______[Blank 5] the pupils to examine the retina. Using an ________[Blank 6], I was able to examine the lenses for signs of ______[Blank 7]. I was able to determine that Mrs. Fox has posterior _________[Blank 8] cataracts in both eyes.
PLAN: I explained to Mrs. Fox that she required cataract _________[Blank 9]. I explained that her clouded lens would be replaced with an _________[Blank 10] lens – a clear artificial lens. She was in agreeance to having the surgery. I told her we would perform the surgery on her right eye first, then in about eight weeks we would do the left eye. Arrangements for her surgery will be made for next month.
_____________________________
Brian Gates, MD, Ophthalmology
Check your answers [1]
Activity source: Sensory System – Consultation Report by Heather Scudder, from Building a Medical Terminology Foundation by Kimberlee Carter and Marie Rutherford, licensed under CC BY- 4.0. / Text version added.
Sensory System – Consultation Report
Sensory System – Consultation Report Activity (Text Version)
Use the words below to fill in the consultation report:
- OS
- watering
- antihistamines
- ophthalmalgia
- erythematous
- thyroid
- abnormalities
- masses
- anaesthetic
- puncta
- nasolacrimal
- dacryocystitis
- dacryocystorhinostomy
- medication
PATIENT NAME: Rose MACKENZIE
AGE: 57
SEX: Female
DOB: November 25
DATE OF CONSULTATION: April 16
CONSULTING PHYSICIAN: Ashley Cook MD, Ophthalmology
REASON FOR CONSULTATION: Epiphora in left eye.
HISTORY: Patient is a 57-year-old female who reports epiphora in ________[Blank 1]. Prior to the encounter, she attempted to cure the condition with various ___________[Blank 2]. She states that this has been an ongoing issue for the past 2 years, but the __________[Blank 3] has affected her ability to safely drive over the past 8 months. She denied any persistent _____________[Blank 4], although noted that the surface of the eye was occasionally irritated and _____________[Blank 5] due to rubbing away the tears. She has had no prior eye surgery and no relevant family or personal history of dermatitis or ___________[Blank 6] pathologies.
PHYSICAL EXAMINATION: Patient is alert and oriented x 3, and in no acute distress. Examination of the eye surface revealed no ___________[Blank 7] other than the erythema and tearing. The skin surrounding the eye appeared normal, with no ___________[Blank 8] or swelling.
An irrigation test was then conducted. The eye was treated with ____________[Blank 9] eye drops prior to the test. A syringe filled with saline was inserted into the left _____________[Blank 10] using a hollow wire. The syringe was then pressed to assess the pressure of the left ____________[Blank 11] duct. The fluid did not pass through the nose, indicating inflammation of the duct. No further diagnostic testing was required.
ASSESSMENT: Chronic ____________[Blank 12] of the left nasolacrimal duct.
PLAN: Return for _____________[Blank 13] in 3 months. Patient was instructed to remove tears using tissue instead of her hand to avoid the risk of infection. No _____________[Blank 14] is required in the meantime.
_______________________________
Ashley Cook MD, Ophthalmology
Check your answers [2]
Activity source: Sensory System – Consultation Report Activity by Sheila Bellefeuille & Heather Scudder, licensed under CC BY- 4.0 from “Sensory Systems” in Building a Medical Terminology Foundation by Kimberlee Carter and Marie Rutherford, licensed under CC BY- 4.0. /Text version added.
Medical Specialties and Procedures Related to the Sensory Systems
Several medical specialties support the sensory systems. An optometrist is an eye specialist that examines and evaluates for ocular pathology and an optometrist prescribes corrective lenses. An ophthalmologist evaluates and manages eye pathology as well as performs surgery. An otorhinolaryngologist (ENT) is a physician that specializes in the ears, nose and throat treatment and conditions. An audiologist evaluates and manages individuals with hearing loss.
Attribution
Except where otherwise noted, this chapter is adapted from “Sensory Systems” in Building a Medical Terminology Foundation by Kimberlee Carter and Marie Rutherford, licensed under CC BY 4.0. / A derivative of Betts et al., which can be accessed for free from Anatomy and Physiology (OpenStax). Adaptations: dividing Sensory Systems chapter content into sub-chapters.
- 1.eye, 2.halos, 3.acuity, 4.iris, 5.dilate, 6.ophthalmoscope, 7.cataracts, 8.subcapsular, 9.surgery, 10.intraocular ↵
- 1.OS, 2.antihistamines, 3.watering, 4.ophthalmalgia, 5.erythematous, 6.thyroid, 7.abnormalities, 8.masses, 9.anaesthetic, 10.puncta, 11.nasolacrimal, 12.dacryocystitis, 13.dacryocystorhinostomy, 14.medication ↵
Pain in the ear
inflammation of the middle ear
Inflammation of the external ear. Aka. swimmer's ear.