cranial nerve conditions Flashcards
olfactory nerve conditions
=affects CNI. referred to as dysomia (olfactory dysfunction)
caused by: nasal and sinus diseases; clogging of nasal passages and inflaming tissues that receive olfactory molecules.
pop: men. older age
risk factors: conditions related to the nose, head trauma, brain tumours, toxins in the environment, medications that control high blood pressure, head & neck cancer radiation, diabetes, vitamin deficiency
s&s: hyperosmia, hyposmia, anosmia, parosmia, phantosmia
treatment: No specific treatment to reverse the change in sense of smell
Sometimes resolves in own time. certain foods stimulate receptors, surgery to eliminate obstructions
glaucoma
=common eye condition where the optic nerve, which connects they eye to the brain, becomes damaged. There are 4 types: open-angle glaucoma, closed-angle glaucoma, congenital glaucoma, and secondary glaucoma
caused by: open-angle=the trabecular meshwork isn’t draining properly. closed-angle= iris is squeezed against the cornea, blocking the uveoscleral drains and the trabecular meshwork. Causing fluid to build up, which increases pressure inside the eye
pop: age over 55, Black, Asian or Hispanic heritage
risk factors: high internal eye pressure, family history of glaucoma, certain medical conditions such as diabetes, migraines, high blood pressure and sickle cell anaemia, eye injury or certain types of eye surgery, and taking corticosteroid medicines
s&s: intense eye pain, nausea and vomiting, a red eye, headaches, tenderness around the eyes, seeing rings around lights, and blurred vision
treatment: isn’t a cure for glaucoma, but early treatment can often stop the damage and protect vision. need to lower intraocular pressure (eye drops, beta blockers, carbonic anhydrase, laser therapy, drainage tubes, minimally invasive glaucoma surgery
Papilledema
=disc swelling increases intracranial pressure
caused by: Raised intracranial pressure, Swelling in the brain, Optic disc being pushed forwards, Obstructive hydrocephalus, Cerebral venous sinus thrombosis, Intracranial masses
pop: 20-40 y/o females
Predominantly with a higher BMI
risk factors: Tumor - cancer, Swelling in the brain, Obstruction of ventricles
s&s: headaches (worse after lying down), overweight, raised intracranial pressure, too much cerebral spinal fluid, blurred, double, flickering, loss of vision, pulsating/ whoosing noise in ear, nausea/ vomiting, weak/ no optic pulse
treatment: shunt put in back of neck to reduce build up of fluid, diamox (reduces potassium levels in blood & lowers pressure in head)
optic neuritis
=inflammation of the optic nerve
causes: Unknown but believed autoimmune response
pop: individuals between the ages of 20 and 40. Women are affected more often than men
risk factors: family history of autoimmune disorders, a recent viral infection, and exposure to certain medications or toxins
s&s: decreased or blurry vision, often accompanied by eye pain that worsens with eye movement. Other symptoms may include color desaturation, flashing lights, or visual field defects
treatment: Most people with optic neuritis recover their vision within several weeks to months without any treatment. vision loss may be permanent, and individuals with optic neuritis may be at increased risk of developing multiple sclerosis or other neurological conditions
ddx: multiple sclerosis, neuromyelitis optica, and acute ischemic optic neuropathy
optic nerve neuropathy
=a condition that involves damage or dysfunction of the optic nerve
caused by: vascular disorders, inflammation, infections, tumors, traumatic injury, or exposure to toxins or medications
patho: When the optic nerve is damaged, it can disrupt the transmission of this visual information, resulting in vision loss or visual disturbances.
pop: older adults
risk factors: family history of the condition, underlying medical conditions such as diabetes or multiple sclerosis, exposure to toxins or medications, and smoking
s&s: vary depending on the severity and location of the damage. The most common symptom is vision loss, which can range from mild blurring to complete blindness. Other symptoms may include changes in color vision, visual field defects, and difficulty with contrast sensitivity
prognosis: vision loss may be permanent, while in other cases, vision may improve with treatment
Macular degeneration
=Common eye condition that affects the macula - the central portion of the retina
caused by: Dry AMD= unknown. links to Ageing, Smoking, High blood pressure, Being overweight, Genetics, Prolonged UV exposure, Diabetes
wet AMD= abnormal blood vessel growth in the retina
pop: predominantly >50 years. Women affected more than men. Two thirds of AMD sufferers are women. One third men
risk factors: Increasing age (>50), Genetics - (Family history of AMD increases risk), Smoking, Female gender, Being overweight/obese, Cardiovascular disease - (high BP, cholesterol, other CVD increases risk), Diet - (High saturated fats), Prolonged sun exposure
s&s: Blurred/distorted central vision, Dark or empty areas in the centre of the visual field - which can create a “blind spot” in the middle of the vision (visual field test needed for this), Reduced colour vision - dimming/fading of colours, Difficulty adapting to changes in lighting/darkness, Straight lines may appear distorted or wavy, A gradual or sudden decrease in visual acuity over time.
Wet AMD causes a more sudden and severe vision loss as it progresses more quickly.
treatment: depends on type. dry= through vitamin supplements, improving diet, and smoking cessation.
Other causes of optic nerve disorder
DM, MS, Hypertension, B12 Deficiency etc.
Oculomotor nerve palsy
=Lesions within the orbit
caused by: Diabetes mellitus = inadequate blood flow, Hypertension = inadequate blood flow, Microvascular infarction, Vascular ischemia, Trauma, intracranial neoplasm, Haemorrhage, Congenital, Idiopathic
pop: >60YOA
risk factors: Diabetes mellitus, High blood pressure, Atherosclerosis, Age
s&s: Diplopia, Ptosis, Eye positioned downwards and outwards with the inability to adduct or move upward and downward, Dilated pupil with sluggish reaction – reflexes are impaired, They become fixed and dilated due to paralysis of sphincter pupillae
treatment: with spontaneous regression of symptoms within several weeks. Demyelinated lesions can remyelinate resulting in spontaneous recovery
Trochlear nerve palsy
=Paralysis/ damage to CN4
caused by: congenital, trauma (Moderate frontal head trauma, frequent cause of bilateral trochlear nerve palsy), vascular
pop: More common in male gender- possibly due to higher incidence of head trauma, Presents in 4th decade of life, Post-head injury cases, most common presentation in 3rd decade of life
risk factors: past ocular history, osteoarthritis, diabetes, hypertension, aspirin
s&s: double vision, images rotated, diplopia, abnomal head posture, facial asymmetry
treatment: often spontaneous recovery
prism glasses, Injection of botulinum toxin into the overreacting inferior oblique, inferior oblique weakening with additional vertical and horizontal rectus surgery
trigeminal neuralgia
=Trigeminal nerve controls facial and corneal sensations and muscle mastication. Splits into 3 branches- mandibular, maxillary and ophthalmic branches
typical=painful episodes that are sharp, intense and sporadic
atypical= less painful and intense but more widespread
caused by: Due to restricted blood flow or compression of the nerve- compression usually caused by a blood vessel typically at the brain stem, Idiopathic- unknown cause, Secondary- caused by another condition- tumors, cysts, MS, injury, surgery and dental surgery, MS, Tumor
risk factors: females, 50+, Infarction, Brainstem glioma, Acoustic neuroma, Neoplasm, Aneurysm of carotid, Thrombosis of cavernous sinus
s&s: Electric shock feeling in 1 side of face typically in the jaw, teeth and gums, Severe episodes of shooting or jabbing pain, Spontaneous attack of pain triggered by touching the face, chewing. Speaking, brushing teeth, wind, movement of the face/ head, Attack last a couple seconds to a few minutes, Facial spasm, Pain in jaw, cheek, mouth, teeth, gums, lips, eyes, forehead, Unilateral, Rarely at night, Cluster headaches, Jaw deviates as the mouth opens, Reduced sensations, Facial weakness, Hearing loss. Symptoms come on suddenly and experience attacks for days/ weeks/ months regularly
treatment: Episodes last week’s/ months and years followed by pain free episodes. Anticonvulsants, Botox, Muscle relaxants, Antispasmodic, Surgery, Low-impact exercise, Acupuncture
ddx: Herpes zoster, Postherpetic neuralgia, Dental pain, Trigeminal neuropathy, TMJ syndrome, Neuralgiform headache attacks, Glossopharyngeal neuralgia
trigeminal palsy
=causes painful sensations (like an electric shock) on one side of the face
caused by: Nerve being compressed by a blood vessel – vein or artery, Can cause be caused by a tumour compressing the trigeminal nerve, Brain lesion or other abnormalities, Surgical injuries, Stoke, Facial trauma
pop: Primarily affects the elderly, 3:2 preponderance in women
risk factors: More common in women, Usually 50+yrs old, Hypertension
s&s: Episodes of sever, shooting or jabbing pain, Spontaneous attacks of pain or attacks triggered by touching the face, chewing, speaking or brushing teeth, Attacks of pain that last from a few seconds to several minutes, Pain that occurs with facial spasms, Bouts of multiple attacks lasting days, weeks, months, or longer – may have periods when they don’t experience the pain, Pain in areas supplied by the trigeminal nerve – cheek, jaw, teeth, gums, lips (less often in eyes or forehead), Pain affects only one side of the face at a time, Pain may be focused in one spot or spread in a wider pattern, Usually doesn’t occur at night while sleeping, Attacks become more frequent and intense over time
prognosis: Usually, a long-term condition but the periods of remission often get shorter with time, It is not life-threatening but can lead to lifelong pain and can be disabling
abducens nerve palsy
=The sixth nerve supplies the lateral rectus muscle, which abducts the eye. Sixth nerve palsy causes an esotropia due to unopposed action of the antagonistic medial rectus muscle
caused by: Stroke, Trauma, Aneurysm, Compression of the nerve by lesions in the cavernous sinus, orbit, or base of the skull, Increased intracranial pressure, Carcinomatous meningitis, Viral illness, Neoplasm, Wernicke’s disease, Brain tumour, Inflammatory lesions (sarcoid, lupus), Infection (Lyme disease, syphilis, tuberculosis), Migraine headache, Multiple sclerosis, Procedure-related injury (spinal anaesthesia, post-lumbar puncture)
pop: adults
risk factor: inflammatory and microvascular conditions, Poorly controlled diabetes mellitus
s&s: Depends on underlying cause, If due to raised intercranial pressure – headache, pain around the eyes, nausea, vomiting, or pulse synchronous tinnitus, If there is a lesion – other neurological signs may be observed, If result of brainstem lesion – ipsilateral facial weakness, contralateral hemiparesis, or sensory abnormalities, Binocular horizontal diplopia when looking to the side of paretic eye, Eye is slightly adducted when patient looks straight ahead – eye abducts sluggishly, and even with max abduction the lateral sclera is exposed, With complete paralysis they eye cannot abduct past midline
prognosis: Depends on underlying cause. If caused by viral infection, then it usually remits completely, If due to secondary trauma, then there may be residual symptoms, Most significant improvement typically occurs within first 6 months, If idiopathic then full recovery is expected – although some may experience permanent vision changes.
facial nerve palsy
=a weakness of the facial muscles which is a result of temporary or permanent damage to the facial nerve
first degree injury–> nerve is concussed or bruised and will recover in about 8 weeks
second degree injury–> more severe damage to the facial nerve, but it still retains its outer layer. First sign of recovery is 4 months
third degree injury–> more severely damaged, and recovery is slower and incomplete. Nerve may be completely severed, and surgical repair is needed to restore facial function
caused by: bells palsy, viral infections, surgical causes, bacterial causes, neurological causes, traumatic injury, birth trauma, rare genetic condition, stroke
patho: facial nerve non-functioning or missing, the muscles do not receive the necessary signals in order to function properly. This results in paralysis of the affected part of face, Due to the facial nerve running through a narrow bony canal within the intertemporal course, any cause of inflammation or growth of the nerve will result in ischaemic changes through compression
s&s: may be sudden or insidious. normally paralysis in one side of the face- but may be both, complete facial palsy affects brow, eye, cheek and mouth- may appear flattened and movement may be lost, may affect sensation such as pain (this indicates trigeminal nerve damage alongside facial nerve), may not be able to feel face when touching it, inability to blink/ close eye, Forehead- loss of wrinkles and inability to frown, Eye area- droopy eyebrow and inability to raise eyebrow, dry eye, sensitivity to light, inability to squint etc, Mouth- droops, inability to smile, altered taste, difficulty eating/ drinking, difficulty speaking, Ears- pain in/ near affected ear, loss of hearing, increased sensitivity to high pitched noise, Nose- runny rose/ stuffy, inability to flare nostril, inability to wrinkle nose
pop: Can affect any gender, Can affect any race, Highest in 15–45-year-olds
risk factors: Pregnant people (especially in the 3rd trimester or 1st week after birth), People with upper respiratory infection, People with diabetes, People with high blood pressure, Obesity, Dormant viral infection, Infection of facial nerve and resulting inflammation, Damage to myelin sheath
treatment: medication–> corticosteroids- reduce swelling of facial nerve so it fits more comfortably in bony corridor, antiviral drugs
Physical therapy–> a paralyzed muscle will shrink and shorten which could be permanent- physical therapy can stop this from occurring.
surgery–> plastic surgery e.g., eyebrow lift, eyelid lift, facial implants and nerve grafts
ddx: Stroke, subdural haematoma, brain tumour, acute otitis media, cholesteatoma, viral infection, neoplasm
Acoustic neuroma
=a noncancerous and usually slow-growing tumor that develops on the main (vestibular) nerve leading from your inner ear to your brain
caused by: a problem with a gene on chromosome 22. Normally, this gene produces a tumor suppressor protein that helps control the growth of Schwann cells covering the nerves-no known cause. This faulty gene is also inherited in neurofibromatosis type 2
risk factors: having a parent with the rare genetic disorder neurofibromatosis type 2
s&s: Hearing loss, usually gradually worsening over months to years — although in rare cases sudden — and occurring on only one side or more severe on one side, Ringing (tinnitus) in the affected ear, Unsteadiness or loss of balance, Dizziness (vertigo), Facial numbness and weakness or loss of muscle movement
treatment: monitoring, surgery to remove tumour, tumour
BPPV
(Benign paroxysmal positional vertigo)
=one of the most common causes of vertigo
caused by: often idiopathic. if there is associated with a minor to severe blow to your head. less common: damage your inner ear or, rarely, damage that occurs during ear surgery or long periods positioned on your back
risk factors: most often in people age 50 and older, but can occur at any age. BPPV is also more common in women than in men. A head injury or any other disorder of the balance organs of your ear may make you more susceptible to BPPV.
s&s: Dizziness, A sense that you or your surroundings are spinning or moving (vertigo), A loss of balance or unsteadiness, Nausea, Vomiting
treatment: may go away on its own. to help relieve symptoms canalith repositioning procedure. surgery= a bone plug is used to block the portion of your inner ear that’s causing dizziness
