systemic plastics Flashcards
sarcoidosis affects MC which part of the eye
anterior/posterior uveitis (30-70% depending on the series) conjunctival nodules (40%) lacrimal gland (40-60% of patients with orbital sarcoid)
In the head/neck - has a particular affinity for the lacrimal gland and parotid gland. B/c CN7 passes through parotid (often sarcoidosis can affect peripheral facial nerve)
Horner’s 2nd order and dilating gtts
Horner’s syndrome is a disruption of the sympathetic chain from the hypothalamus to the pupil. Disruption causes unopposed parasympathetic action which causes a small pupil (miosis).
Cocaine blocks the reuptake of norepinephrine (the neurotransmitter of sympathetic nerves). Because the neurons in the sympathetic chain are not working, they do not release norepinephrine and thus the Horner’s PUPIL WILL FAIL TO DILATE. The normal eye will dilate.
Hydroxyamphetamine causes forced release of norepinephrine from non-damaged third order neurons.
Patient would have dilation of both pupils with the administration of hydroxyamphetamine (if 1st or 2nd order problem). Horner’s pupil would NOT dilate if 3rd order problem
TAO and Graves
Graves disease occurs in 90% of patients with TAO. But not all patients have Graves disease.
- 6% are euthyroid, 3% have Hashimotos, and 1% have primary hypothyroidism.
- Almost all patients with TAO will be hyperthyroid at some point.
- Only 30% of hyperthyroid patients will develop TAO.
silent sinus syndrome (SSS) (aka, chronic maxillary atelectasis (CMA)
Acquired collapse of the maxillary sinus related to chronic hypoventilation of the maxillary sinus
PMH: allergies or chronic sinusitis that is thought to lead to obstruction of the middle meatus leading to negative pressure development within the maxillary sinus.
Si/Sx: history of insidious onset of binocular diplopia and enophthalmos
Dx: Collapse (or atelectasis) of the right maxillary sinus with resultant downward shift of the inferior rectus muscle
-in-bowing of the superior wall of the maxillary sinus (the orbital floor) that is sharply contrasted by the normal outbowing of the contralateral superior maxillary sinus wall.
Rx:
1) maxillary antrostomy (often endoscopic) to allow for improved drainage / ventilation of the maxillary sinus
OR
2) maxillary antrostomy PLUS reconstruction of the orbital floor with an implant. Patients with significant diplopia and enophthalmos require orbital floor reconstruction to keep the orbital contents in the orbital space and maxillary antrostomy to prevent further maxillary sinus collapse.
DDx: 1) trauma damages the integrity of the middle meatus
2) Sinonasal malignancies (requiring surgical intervention, radiation, or chemotherapy) could destroy the maxillary sinus with radiographic opacification but does not typically cause collapse of the sinus, would be expected to demonstrate invasion of adjacent bony structures, and would present more acutely than this patient who presented over 2 years.
3) fungal etiology
early surgical intervention orbital cellulitis (peds pts)
Criteria for early surgical intervention of subperiosteal abscess:
Anaerobic concern:
- Age greater than 9 or older (more likely to have anaerobic, polymicrobial, or resistant organisms)
- Infection of dental origin (more likely to be anaerobic organisms)
- Suspicion of anaerobic subperiosteal infection (i.e. presence of gas on CT)
Presence of frontal sinusitis
Non-medial location of subperiosteal abscess
Evidence of chronic sinusitis
Recurrent abscess after previous drainage
Acute optic nerve or retinal compromise
Large subperiosteal abscess
GCA
ESR is markedly elevated in 90% of patients. A good rule of thumb for the upper value of ESR is:
[age] / 2 (males) or [age + 10] / 2 (females).
Other factors that suggest GCA:
- elevated CRP and platelet count (generally above 400,000/µl) increase specificity for the diagnosis.
- A high white blood cell count
- low hemoglobin and hematocrit
> 50 yo
F: M =2-4x: 1
Si/Sxdamages vision by vasculitic occlusion of the posterior ciliary arteries that supply the optic nerve head and choroid; therefore, it is common to see “pallid” disc edema due to severe ischemia along with patchy choroidal filling on FA in the affected eye (and sometimes even the seemingly unaffected contralateral eye).
Gold standard Dx: temporal artery biopsy (3-6 cm) False negative (3-9%) 2/2 discontinuous vasculitic involvement of the temporal artery in GCA do contralateral side if negative and high suspicion
Rx intravenous methylprednisolone (1 gram/day for 3-5 days) when vision loss is present and oral prednisone (60-100 mg/day) when GCA occurs without vision loss.
Treatment will generally NOT reverse vision loss in the affected eye, but it is used to prevent vision loss from worsening in the affected eye and also to prevent disease in the contralateral eye.
which muscle enlargement most concerning for ON compression in TAO?
Given the anatomy of the orbit with the optic canal being located posteromedially in the lesser wing of the sphenoid, enlargement of the MEDIAL RECTUS muscle would be most concerning for developing a compressive optic neuropathy.
Rx: pulsed IV steroids, orbital radiation, or probably orbital decompression.
Botox action
Rx: benign essential blepharospasm
Mechanism: Both toxins work by PREVENTING THE RELEASE of acetylcholine from the presynaptic junction.
botulinum toxin A (Botox) or botulinum toxin B (Myobloc). -Botulinum toxin type B cleaves a component of the soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptor (SNARE) complex and inhibits release of acetylcholine.
A healthy 62-year-old patient comes in for exam. He complains of boring pain in the upper right-hand area of his orbit that came on suddenly in the last 48 hours. He has no constitutional symptoms and no past medical history. You order a CT scan and CBC. The CBC is normal and the CT shows an enlargement of the lacrimal gland and lateral rectus muscle insertion. Which of the following is the next most appropriate treatment?
orbital pseudotumor
aka nonspecific orbital inflammation (NSOI)
DDx: metastases, ruptured dermoid cysts, and infections.
Rx: Oral steroids rapidly Rx manner.
Dx: Normal CBC coupled with muscle TENDON inflammation point reliably to nonspecific orbital inflammation (NSOI) as the cause. If the presentation is classic for NSOI a biopsy and systemic work up is not always necessay
If bilateral in adults, needs systemic work-up for vasculitis or lymphoma In children, 33% bilateral B-scan: low reflectivity Most commonly affects which muscle? MR & LR
Treatment? Steroids, NSAIDs
Criteria for NF1
The clinical diagnosis of NF1 consists of the patient exhibiting 2 or more of the following criteria:
a first-degree relative with NF1
6 or more cafe-au-lait spots
2 or more neurofibromas or 1 plexiform neurofibroma
axillary/inguinal/or other intertriginous freckling
2 or more Lisch nodules
a distinctive osseous lesion (e.g. sphenoid bone dysplasia)
optic nerve glioma
CALBORN
Myasthenia and TAO
Thyroid eye disease (TED)
-most often affects middle-aged and older patients, but when it occurs in YOUNG PATIENTS, they often exhibit EXPANSION OF THE INTRACONAL FAT more prominently than severe hypertrophy of the extraocular muscles.
If no restricted motility in either eye but problems moving the eye (think of myasthenia gravis)
- co-exist Myasthenia (1-5%)
1) ordering a myasthenia antibody panel
2) consider an EMG
TAO vs dural shunt
Thyroid associated ophthalmopathy (TAO).
- common sign = vascular congestion over the rectus muscles
- with TAO, the vascularization stops at the muscle insertions and there is a clear area from there to the limbus.
Dural shunts also are characterized by conjunctival vascular congestion.
- With dural shunts, the erythematous conjunctival blood vessels extend over this area.
PHACE syndrome
Large capillary hemangioma close to the globe - important to perform a full cycloplegic exam to examine for refractive error or retinal vascular anomalies.
Assocation of retinal vascular anomalies with a large facial hemangioma in this location is concerning for PHACE syndrome
(Posterior fossa malformations, Hemangiomas, Arterial anomalies, Coarctation of the aorta, and Eye abnormalities).
Segmental hemangioma in the region of the lateral forehead ABOVE THE BROW = at increased risk for having cerebrovascular and ocular anomalies.
Hemangiomas in the midline region AROUND THE CHIN are at increased risk for ventral and cardiovascular anomalies.
PHACE syndrome does not typically manifest with genitourinary anomalies.
What is the use of the different components of a retrobulbar block?
Hyaluronidase helps disperse lidocaine to a greater degree. Epinephrine constricts blood vessels and prevents the elimination of lidocaine thus increasing the time of action. Sodium bicarbonate buffers the solution and decreases the pain on injection of lidocaine.
pseudotumor
Nonspecific orbital inflammation (NSOI) is defined as a benign inflammation of the orbit without a known local or system cause. The BCSC uses the term NSOI; other terms that have been used for this entity are “orbital pseudotumor”, “idiopathic orbital inflammation”, and “orbital inflammatory syndrome”. The cause of NSOI is currently controversial, but many experts believe it is an immune-mediated process because it is often associated with immune disorders like lupus or rheumatoid arthritis and is exquisitely sensitive to systemic corticosteroid treatment. (Yes, we understand that the association of NSOI with systemic immune conditions somewhat contradicts its stated definition, but this is what the BCSC states).
According to the BCSC, NSOI occurs (in order of frequency) in these 5 primary locations within the orbit:
Extraocular muscles ("myositis")
Lacrimal gland ("dacryoadenitis")
Anterior orbit ("scleritis")
Orbital apex
Diffusely throughout the orbit
In addition, many experts consider optic perineuritis (or inflammation of the optic nerve sheath) to be another manifestation of NSOI. While optic perineuritis can occur from known causes such as Wegeners, sarcoidosis, and tuberculosis, most cases are "idiopathic" and probably fall under the umbrella of NSOI.
The clinical symptoms of NSOI vary according to the involved structure(s), but typically consist of deep-rooted, boring pain. Orbital signs (e.g. proptosis, extraocular muscle restriction) and ocular inflammation (e.g. conjunctival injection, chemosis) are both typical of this condition. Visual compromise occurs if the optic nerve or posterior globe is involved (e.g. optic perineuritis and posterior scleritis).
Imaging findings that are high-yield to know:
Dacryoadenitis: diffuse enlargement of the lacrimal gland.
Myositis: diffuse thickening of the extraocular muscles with involvement of the tendons. In contrast, the tendons of the extraocular muscles are rarely thickened in thyroid eye disease.
Most cases of NSOI in adults are unilateral. This contrasts with children where approximately 1/3 of NSOI cases are bilateral. Also, NSOI in children is rarely associated with systemic conditions.
Once the diagnosis of NSOI has been definitively made (i.e. other diagnoses excluded), then initial treatment of NSOI is with systemic corticosteroids. Typical initial dosage is prednisone 1 mg/kg. Most cases of NSOI respond favorably to systemic corticosteroids with the notable exception of the subtype of NSOI called sclerosing NSOI. This subtype has minimal cellular inflammation and abundant fibrosis and frequently requires biopsy for proper diagnosis. Sclerosing NSOI typically needs more aggressive immunosuppression (e.g. cyclosporine, methotrexate).
