Smell, Vision, Taste
Cranial nerve disease is impaired functioning of one of the twelve cranial nerves. Each cranial nerve controls functions like smell, vision, and balance. Disorders include trigeminal neuralgia, acoustic neuroma, hemifacial spasm, facial nerve disorder, and intractable vertigo.
The 12 Cranial Nerves
- Olfactory: Smell
- Optic: Transmit visual information to the brain
- Oculomotor: Eye movement
- Trochlear: Lateral eye tracking
- Trigeminal: Facial sensation
- Abducens: Lateral eye tracking
- Facial: Facial expressions
- Vestibulocochlear (Acoustic): Hearing and Balance
- Glossopharyngeal: Taste and Swallowing
- Vagus: Gag reflex
- Accessory: Neck muscle control, gag reflex
- Hypoglossal: Tongue movement and Swallowing
Bell’s Palsy: also known as facial palsy, is a condition that causes sudden weakness in the facial muscles. This makes half of a person’s face appear to droop. The smile is one-sided, and the eye on that side resists closing. It can occur at any age. The exact cause is unknown, but it is thought to be the result of swelling and inflammation of the nerve that controls the muscles on one side of the face. It may be also be a reaction that occurs after a viral infection. For most people, Bell’s palsy is temporary. Symptoms usually start to improve within a few weeks, with complete recovery in about six months. A small number of people continue to have some Bell’s palsy symptoms for life.
Dilopia: also known as double vision, is when a single image appears double. These images can appear horizontally, vertically, or diagonally in relation to each other. It is usually the result of impaired function of the extraocular muscles where both eyes are still functional, but they cannot converge to target the desired object. Dilopia is often one of the first signs of a systemic disease, particularly to a muscular or neurological process, and it may disrupt a person’s balance, movement, or reading abilities.
Dysphagia: difficulty in swallowing. It is a sensation that food is stuck in the throat, or from the neck down to just above the abdomen behind the sternum (breastbone.) The causes of swallowing problems vary, and it may occur at any age, but is more common in older adults.
External Resource: Dysphagia Research Society
Dysarthria / Stuttering
Dysarthria: also known as stuttering, is a condition that causes problems with the muscles that produce speech, often making it very difficult to pronounce words. It is not related to any problem with understanding language. People who stutter know what they want to say, but they have difficulty saying it. Stuttering can cause difficulties in starting a word, syllable, or phrase and can include the repetition of words or syllables. It can be developmental, where a child’s desire to express himself is greater than his ability to form words; most children outgrow this. However, it can also be due to inherited brain abnormalities, as the result of brain injury, or part of another mental health condition.
External Resource: Voice Health Institute
Nystagmus: also known as dancing eyes, is is a term to describe fast, uncontrollable movements of the eyes. These movements may be up and down, side to side, or rotary. These involuntary eye movements are caused by abnormal function in the areas of the brain that control eye movements. Two types of nystagmus exist. Infantile nystagmus syndrome (INS) is present at birth, usually mild, and unrelated to any other condition. Acquired nystagmus occurs later in life and is the result of disease, injury, or a side effect of certain medications.
Ptosis: also known as drooping eyelid, is a condition where one or both eyelids falls to a lower position than is normal. It can be caused by muscle weakness, nerve damage, or looseness of the skin. It often occurs as the result of normal aging, but can also be present at birth or the result of injury or disease.
External Resource: Retina Foundation of the Southwest
Tinnitus: also known as ringing of the ear, is the perception that one hears ringing when no actual sound is present. Ringing is only one of many sounds that a person may believe he hears. Tinnitus is not a condition itself — it is a symptom of an underlying condition, such as age-related hearing loss, ear injury or a circulatory system disorder.
External Resource: American Tinnitus Association