Head and Neck Flashcards

Question

Petrous apex inflammatory lesions

Answer 1

CHOLESTEROL GRANULOMA Most common primary petrous apex lesion. Obstruction of air cell with repeated cycles of haemorrhage and inflammation leading to expansion and bone remodelling. Symptom is hearing loss. CT margins sharply defined. T1 and T2 bright. T2 dark haemosiderin rim with faint peripheral enhancement. CHOLESTEATOMA Basically an epidermoid (ectopic epithelial tissue). Petrous apex ones are congenital. Slow growing and produce well smooth expansile bony change. T1 dark, T2 bright and restrict diffusion.

Answer 2

REGULAR AND NECROTIZING OTITIS EXTERNA Usually bacterial of external auditory canal. Necrotizing/malignant form almost only in diabetics and is more aggressive. Swollen EAC soft tissues, bunch of small abscesses and adjacent bony destruction. Usually diabetics and infected with pseudomonas. EXTERNAL AUDITORY CANAL EXOSTOSIS 'Swimmers ear". Overgrowth of soft tissue in ear canal, classically surfers with repeated bouts of ear infections. usually bilateral and when chronic looks like bone. These patients are immunocompetent and not diabetic, EXTERNAL AUDITORY CANAL OSTEOMA Overgrowth of normal bone. Usually incidental and unilateral occuring near junction of bone and cartilage in ear canal. EXTERNAL AUDITORY CANAL ATRESIA Developmental. External auditory canal doesnt form. May or may not be mashed up ossicular chain. Key is whether tissue covering the area normally open is soft tissue or bone (atretic plate). Also need to know if there is aberrant course of facial nerve.

Answer 3

Can have osteolysis circumscripta which is well defined large radiolucent region favoring frontal and occipital bones. Both inner and outer table involved. ``` Pagets skull related complications: Deafness Cranial nerve paralysis Basilar invagination to hydrocephalus to brainstem compression Secondary osteosarcoma ```

Answer 4

Midline and off midline - discussed in MSK

Answer 5

Ground glass. Can look similiar to Pagets but FD is young <30 and Pagets older. Fibrous dysplasia spares otic capsule classically McCune Albright syndrome is multifocal FD, cafe au lait spots and precocious puberty Outer table favoured

Answer 6

CT for anterior 2/3 orbit. MRI for posterior 1/3 and cavernous sinus. CT useful for characterization of anatomical variation, MRI for tumour progression/extension/PNI/marrow involvement

Answer 7

ALLERGIC FUNGAL SINUSITIS Opacification of multiple sinuses, usually bilateral favouring ethmoid/maxillary. Normal immune system (asthma common) CT hyperdense centrally or with layers. Can erode and remodel sinus walls when chronic. MRI T1 and T2 dark, high protein and heavy metals. Can mimic aerated sinus. Inflammed enhancing mucosa. ACUTE INVASIVE FUNGAL SINUSITIS Opacificaiton of multiple sinuses. Stranding/extension into fat around sinuses is key. Immunocompromised. Apergillus or Zygomycetes CT opacified sinus not hyperdense. Fat stranding in orbit, masticator fat, pre antral fat or PPF suggests invasion. Does not require bone destruction MRIT1 and T2 dark, mucosa doesnt enhance. Extension of disease out of sinus will be bright on STIR and enhance

Answer 8

Inflammation of paranasal sinuses lasting at least 12 weeks. Issue is primarily anatomical patency of sinus ostia See p254 vol 2 yellow book INFUNDIBULAR PATTERN Most common. Disease limited to maxillary sinus and occurs from obstruction at ipsilateral ostium/infundibulum OSTIOMEATAL UNIT PATTERN Second most common. Centred at middle meatus with disease involving ipsilateral maxillary, frontal and ethmoid sinuses. Contributors are: hypertrophied turbinates, anatomic variants, concha bullosa, middle turbinates curling wrong way, septal deviation. SINONASAL POLYPOSIS PATTERN Combination of soft tissue nasal polyps and variable degrees of sinus opacification. Fluids levels can be present. Bony remodelling and erosion are key. Widening of infundibula. Need to differentiate between erosion/remodelling and expansion (mucocoele). Associations are CF and aspirin sensitivity. MUCOCOELE Obstructed sinus. May have had prior trauma. May have CF with secretions clogging things up. Mucus accumulates, sinus becomes completely filled and starts to expand. buzzword is expanded airless sinus. Frontal sinus most common. Periphery may enhance.

Answer 9

Young adults 30-40. Presents with congestion/obstruction. Arises within maxillary sinuses and passes through and enlarges sinus ostium. Buzzword widening of maxillary ostium. Smooth enlargement of the sinus with no bony destruction.Polyp will extend into nasopharynx. Monster inflammatory polyp

Answer 10

Male teenager with nose bleeds. Centred in sphenopalatine foramen. Bony remodelling (not destruction). Very vascular and enhancing with intratumoral flow voids on MRI. Presugical embolization common via internal maxillary and ascending pharyngeal artery. Maxillary sinus in front smaller due to bony remodelling.

Answer 11

Uncommon tumour. Lateral wall of nasal cavity most frequently related to middle turbinate. Impaired maxillary drainage expected. Focal hyperostosis occurs at tumour origin. 10% harbour a squamous cell Ca. Cerebriform pattern.

Answer 12

Neuroblastoma of olfactory cells, starts at cribriform plate. Dumbbell appearance with growth up into skull and down into sinuses with a waist at the plate. Often cysts in mass. Bimodal age distribution. Dumbbell shape Intracranial posterior cyst classic octreotide scan positive - neural crest origin

Answer 13

Squamous cell is most common tumour head and neck. Maxillary antrum is most common location. Highly cellular, low T2. Relative to other sinus masses it enhances less. SNUC is monster version of regular squamous cell.

Answer 14

Usually idiopathic though can be iatrogenic. Could be in setting of HHT (hereditary haemorrhagic telangiectasia). also called osler weber rendu). Anterior septal area (Kiesselbach plexus) is most common and can be compressed manually. Posterior ones are less common but bleed more. Main supply posterior nose is sphenopalatine artery (terminal internal maxillary artery) and tends to be first target. Watch out for variant anatomy between ECA and ophthalmic artery.

Answer 15

Typically involves anterior septal cartilagenous area. ``` Surgery (Killian submucous resection) Cocaine use Too much nose picking Granulomatosis with polyangitis (Wegeners) which is renal masses, sinus mucosal thickening and nasal septal erosion and cavitatory lung nodules/fibrosis. cANCA positive. Syphillis ```

Answer 16

Stones in salivary duct, most commonly submandibular gland duct (Whartons). Can lead to infected gland "sialoadenitis" and chronic obstruction which can lead to fatty atrophy. Submandibular - Whartons duct Parotid - Stensons duct Sublingual - Rivinus duct

Answer 17

Can be dental or periodontal in origin. More common from an extracted tooth than an abscess involving an intact tooth. Attachment of mylohyoid muscle to mylohyoid ridge dictates spread of infection to sublingual and submandibular spaces. Above mylohyoid line (anterior mandibular teeth) goes to sublingual space. Below mylohyoid line (posterior mandibular teeth) goes to submandibular space. Odontogenic abscess is most common masticator space mass in adult.

Answer 18

Aggressive cellulitis in floor of mouth, will be shown with gas in tissues. Most cases start with odontogenic infection

Answer 19

Normal variant. Bony exostosis arising from hard palate in midline.

Answer 20

Related to prior radiation or bisphophanate treatment.

Answer 21

Mucous retention cyst, typically lateral. Arise from sublingual space and are termed plunging if under mylohyoid muscle

Answer 22

Anywhere between foramen cecum and thyroid gland. Usually in midline. Thin walled cyst.

Answer 23

Buzzword is 'sack of marbles' fluid sack with globules of fat. Typically midline

Answer 24

Squamous cell most common in mouth. think drinker/smoker. In young person think HPV, usually with large necrotic level 2 node.

Answer 25

Most common type. Result of inflammation of dental caries. Cystic degeneration around periodontal ligament. Apex of non vital tooth. Round with well corticated border. Usually <2cm.

Answer 26

Cyst around crown of unerupted tooth. Developmental cyst. Displaces and absorbs adjacent teeth. Can displace tooth into condylar regions or into floor of orbit

Answer 27

Occur at mandibular ramus or body. Classic is multilocular. ``` Body/ramus Grow along length of bone No significant cortical expansion May have daughter cysts When multiple think Gorlin syndrome ```

Answer 28

``` Locally aggressive. Multicystic with solid components and expansion of the mandible. "soap bubbles" Extensive tooth resorption. Mandibular expansion Solid component 5% arise from dentigerous cysts ```

Answer 29

Start out lucent. Most common odontogenic tumour of mandible. Tooth hamartoma. Radiodense with lucent rim. Can be large with fluffy calcifications.

Answer 30

Parotid gland Portions of facial nerve Retromandibular vein Parotid gland only salivary gland to have lymph nodes

Answer 31

PLEOMORPHIC ADENOMA Most common salivary gland tumour. Usually in parotid and usually in superficial lobe. T2 bright. Small malignant potential. Superficial vs deep lobe is important for surgical approach. Benign mixed tumour. WARTHINS Second most common benign tumour. ONLY occurs in parotid. Cystic, male smoker, bilateral (15%). Takes up pertechnate. MUCOEPIDERMOID CARCINOMA Most common malignant tumour of minor salivary glands. Smaller the gland, more common the malignant tumour. Association with radiation ADENOID CYSTIC CARCINOMA Malignant salivary gland tumour that favours small but can be in large glands. Perineural spread.

Answer 32

LYMPHOMA Parotid is only salivary gland with lymph nodes, therefore can get lymphoma. If bilateral, think Sjogrens. Bilateral homogenous masses. SJOGRENS Autoimmune lymphocyte induced destruction of gland. Dry eyes and dry mouth. Typically women in 60s. Raised risk of Non-Hodgkins MALT lymphoma. Honeycombed appearance to gland BENIGN LYMPHOEPITHELIAL DISEASE Bilateral mixed solid and cystic lesions with diffusely enlarged parotids. Seen in HIV. Painless ACUTE PAROTITIS Obstruction of flow of secretions most common. Stone in Stensens duct which will be dilated. Stones are calcium phosphate. Post infectious parotitis usually bacterial. Mumps most common viral.

Answer 33

Mostly just fat with some branches of trigeminal nerve and pterygoid veins Primary utility is when its displaced. Mets and infection can spread through in vertical direction (squamous from tonsils, tongue and larynx). Cystic mass could be branchial cleft cyst but more likely necrotic level 2 lymph node. Posterior is carotid space Lateral is parotid space Superficial mucosal space is medial

Answer 34

Carotid artery Jugular vein Portions of CN9, 10 and 11 Internal jugular chain LNs paragangliomas, schwannomas, neurofibromas, secondary spread of aggressive multispatial disease or malignant spread.

Answer 35

Hypervascular (intense tumour blush). Salt and pepper on MRI - flow voids Can be multiple and bilateral in familial conditions In-Octreotide accumulates in these tumours CAROTID BODY TUMOUR Splaying ICA and ECA at carotid bifurcation GLOMUS JUGULARE Skull base often with destruction of jugular foramen. GLOMUS VAGALE Above carotid bifurcation but below jugular foramen. GLOMUS TYMPANICUM Confined to middle ear overlying cochlear promontory.

Answer 36

Most commonly vagal nerve CN10 but if lesion is high up near skull base it could be involving 9, 11 or 12. Oval mass with heterogenous bright T2. Enhance a lot. NF2 association

Answer 37

Less common than schwannoma. 10% of time related to NF1 in which case they may be multiple and bilateral.

Answer 38

LEMIERRES SYNDROME Thrombophlebitis of jugular veins with septic emboli in lung. In setting of oropharyngeal infection or recent ENT surgery. Fusobacterium necrophorum GRISELS SYNDROME Torticollis with atlantoaxial joint inflammation seen in ENT surgery or retropharyngeal abscess

Answer 39

Muscles of mastication (masticator, temporalis, medial and lateral pterygoids) Ramus of mandible and inferior alveolar nerve. Extends superiorly along side of skull via temporalis muscle so infection can go right up there.

Answer 40

ODONTOGENIC INFECTION Most common cause of masticator space mass. Look at mandible on bone windows. Look out for spread via pterygopalatine fossa to orbital apex and cavernous sinus SARCOMAS Rhabdomyosarcomas in kids. Can get sarcoma from mandible or chondrosarcoma which favors the TMJ. CAVERNOUS HEMANGIOMA Given away by presence of phleboliths. Venous or lymphatic malformations may involve multiple compartments/spaces. Congenital/aggressive infection/cancer tend to be multispatial PERINEURAL SPREAD Can have spread along V3 of trigeminal. Should think either adenoid cystic or melanoma. NERVE SHEATH TUMOUR Can have schwannoma or neurofibroma of V3.

Answer 41

Midline space deep to oro and nasopharynx. Retropharyngeal space is anterior and true space which extends to C6/7. Posterior danger space extends to mediastinum. The two are separated by alar fascia. Behind both is the prevetebral space where thinks like discitis/osteomyelitis go

Answer 42

INFECTION Usually spread from tonsillar tissue. Central low density tissue and stranding in the space. Evaluate for spread into mediastinum. Delays critical to distinguish phlegmon from abscess. NECROTIC NODES Nodes of Rouviere. Located in lateral retropharyngeal region. Kids get suppurative infection in these but start to regress around age 4 with adults much less likely to get infection here. Can get mets or lymphoma here

Answer 43

Anterior belly digastric separates 1A from 1B. Stylohyoid muscle separates 1B from 2A Jugular vein separates 2A from 2B VERTICAL BORDERS 2-3 is lower hyoid 3-4 lower cricoid 5A-5B lower cricoid, both posterior to SCM 6 is anterior and inferior to lower border cricoid 7 is upper mediastinal

Answer 44

Smoker/drinker in old person, HPV in young person. | Necrotic level 2 nodes.

Answer 45

Fossa of Rosenmuller is most common location More common in Asians Bimodal distribution (15-30 and >40) Involvement of the parapharyngeal space results in worse prognosis Unilateral mastoid effusion or pathological retropharyngeal LN check Fossa of Rosunmuller Pathological retropharyngeal LN or supraclavicular LN chek clivus as 30% patients with nasopharyngeal tumours may have skull base erosion

Answer 46

When laryngeal saccule dilates with air you call it a laryngocoele. If filled with fluid it may still be laryngocoele but can now call it a saccular cyst. Saccule is appendix of laryngeal ventricle. Typically closed and not seen in adults. Can dilate if obstructed (ball valve mechanics) and testable point is 15% time obstruction is a tumour. Can see in forceful blowers like trumptet players and glass blowers. Internal and external version based on containment of violation of thyrohyoid membrane

Answer 47

involved side will have expanded ventricle. If seen on left, look into chest for recurrent laryngeal nerve compression at AP window. Hoarseness is buzzword.

Answer 48

85% squamous cell. RISK FACTORS Smoking, alcohol, radiation, laryngeal keratosis, HPV, GORD. SUPRAGLOTTIC More aggressive, early LN mets, dont get hoarseness. Epiglottic centered - anterior, likes to invade pre-epiglottic space/fat False cord centered - posterolateral, likes to invade paraglottic space Aryepiglottic fold mass GLOTTIC Most common, best outcome, grows slowly, late metastatic disease. Usually involve anterior cord and spread to anterior commisure Progressive and continuous hoarseness SUBGLOTTIC Least common, often small compared to nodal burden. Bilateral nodal disease and mediastinal extension.

Answer 49

Most common primary malignancy of globe. Calcification in globe of child. RB suppressor gene c13. Same chromosome osteosarcoma patients get so at risk of these after radiation. Globe should be normal in size or slightly bigger (Coats disease its smaller). Usually seen before age 3. Bilateral both eyes Trilateral both eyes and pineal gland Quadrilateral both eyes, pineal gland and suprasellar

Answer 50

Retinal telengiectasia resulting in leaky blood and subretinal exudate. Can lead to retinal detachment. Young boys, typically unilateral. NOT CALCIFIED

Answer 51

Failure of embryonic occular blood supply to regress. Can lead to retinal detachment. Small eye (microphthalmia) with increased density of vitreous. No calcification

Answer 52

Can be secondary to PHPV or Coats. Can also be just from trauma, sickle cell or old age. See V or Y shape due to uplifted retinal leaves.

Answer 53

``` Retinoblastoma - normal Toxocariasis - normal PHPV - small size (normal birth age) Coats - small Retinopathy of prematurity - bilaterally small ```

Answer 54

Most common intra-occular lesion in an adult. Enhancing soft tissue mass in back of an adults eye. "collar button shaped". Strong predilection for liver mets.

Answer 55

90% under age 20. Expansion/enlargement of entire nerve. If bilateral think NF1. Usually pilocytic astrocytoma WHO1

Answer 56

Tram track calcifications. Doughnut appearance on coronal. Circumferential enhancement around nerve

Answer 57

Most common benign congenital orbital mass. Superior and lateral usually, arising from frontozygomatic suture and presenting <10yo. Has fat in it

Answer 58

Most common extraoccular malignancy in children.Superior medial orbit and classicaly has bone destruction. Bulky orbital mass in a 7 year old. Rare

Answer 59

Association with chlamydia psittaci (bird fever). and MALT lymphoma of orbit. usually involves upper outer orbit closely associated with lacrimal gland. Enhance homogenously and restrict diffusion.

Answer 60

Raccoon eyes o/e. Periorbital tumour infiltration with proptosis. Bony involvement of greater wing of sphenoid. Usually bilateral.

Answer 61

Breast cancer met has desmoplastic reaction and enophthalmos

Answer 62

ORBITAL PSEUDOTUMOUR Idiopathic inflammatory conditions involving extraoccular muscles. Looks like expanded muscle. Painful and unilateral, most commonly involves lateral rectus and does not spare myotendinous junctions. Give steroids TOLOSA HUNT Same thing as orbital pseudotumour but in cavernous sinus. Painful and presents with multiple cranial nerve palsies. Give steroids. LYMPHOCYTIC HYPOPHYSITIS Same as above but in pituitary. Enlarged pituitary stalk in postpartum/3rd trimester woman.

Answer 63

Seen in 1/4 of graves disease, most common cause of exophthalmos. Antibodies hat activate TSH receptors also activate orbital fibroblasts and adipocytes. Risk of compressive optic neuropathy. Enlargement of only muscle belly (spares tendon). NOT painful. Order of involvement IMSLO

Answer 64

LYMPHANGIOMA Mix of venous and lymphatic malformations. Ill defined, lack a capsule. Multispatial and infiltrative. Preseptal, postseptal, extraconal and intraconal. Fluid-Fluid levels. Do NOT distend with provocative maneuvers. VARIX Secondary to weakness in post capillary venous wall. Massive dilatation of valveless orbital vein. Disetent with provocative maneuvers. Most common cause of spontaneous orbital haemorrhage. Can thrombose and present with pain ``` CCAROTID CAVERNOUS FISTULA Direct is from trauma and indirect occurs randomly in postmenopausal women. Direct is a communication between intracavernous ICA and cavernous sinus. Indirect kind usually dural shunt between meningeal branches of ECA and cavernous sinus. Pulsatile exophthalmos (this can also be for NF1 with sphenoid wing dysplasia though) ```

Answer 65

Orbital cellulitis is post septal Periorbital cellulitis is preseptal Orbital septum originates from periosteum of the orbit and inserts in the palpebral tissue along tarsal plate. Preseptal infections start in adjacent structures. Post septal infections usually from paranasal sinusitis. preseptal infections treated medically, post septal is surgical Periorbital abscess can cause thrombosis of ophthalmic veins or cavernous sinus. In extreme cases, usualy aspergillosus, can cause carotid/cavernous fistula

Answer 66

Inflammation and dilatation of lacrimal sac. Well circumscribed round rim enhancing lesion centered in lacrimal fossa. Typically from obstruction followed by bacterial infection (staph or strep). Usually diagnosed clinically unless there is an associated periorbital cellulitis in which case CT needed to exclude postseptal infection from simple dacrocystitis.

Answer 67

Inflammation under periosteum which can progress to abscess formation. Usually associated with ethmoid sinusitis. Classic look.

Answer 68

Will be enhancement of the optic nerve without enlargement of the nerve/sheath complex. Usually 70% unilateral and painful. Often see intracrnial or spinal cord demyelination in setting of Devics (neuomyelitis optica). 50% patients with acute optic neuritis will develop MS

Answer 69

Can see dilatation/swelling of optic nerve sheath. DRUSEN Mineralization at optic disc. Association with age related maculopathy. INTRAOCULAR LENS IMPLANT Standard treatment for cataracts. Replaced lens has thin linear appearance. ``` ECTOPIA LENTIS (LENS DISLOCATION) Causes include trauma, marfans and homocystenuria ```

Answer 70

Focal discontinuity of globe (failure of choroid fissure to close). Usually posterior. If you see bilateral ones, think CHARGE syndrome

Answer 71

TYPE 1 Rare, upper part of odontoid as result of avulsion of alar ligament. May be stable TYPE 2 Fracture at base. High non-union rate. Unstable TYPE 3 Fracture through dens into the body of C2. Unstable

Answer 72

Axial loading injury. Anterior and posterior arches blow out laterally. 30% will also have a C2 fracture. Cord damage rare as all force directed into bones. Open mouth view will show slipping of lateral masses.

Answer 73

These variants can mimc a type 1 dens fracture. Ossicle located at the position of the odontoid tip. With os odontoideum, base of dens is hypoplastic. Prone to sublaxation and instability. Associate with Morquios syndrome. Orthotopic position atop dens. Dystopic when fused to clivus.

Answer 74

Seen usually when chin hits dashboard in MVA (direct blow to face). Fracture through bilateral pars at C2. ANterior subluxation of C2 on C3. Cord damage uncommon as acquired aprs defect allows for canal widening. Associated fracture at anterior/inferior corner of C2 from avulsion of ALL.

Answer 75

``` FLEXION Teardrop shaped fracture fragment at inferior/anterior vertebral body. Bad as 85% will have anterior cord syndrome associated. Unstable fracture associated with posterior subluxtion of vertebral body Impaction injury Extremely unstable hyperflexion "ran into wall" ``` EXTENSION Anterior inferior teardrop shaped fragment with avulsion of ALL. Less serious Distraction injury Stable in flexion (unstable in extension) Hyperextension "hit from behind"

Answer 76

Avulsion injury of lower cervical/upper thoracic spinous process (usually C7). Forceful hyperflexion.

Answer 77

Flexion distraction fractures classically associated with lap band seatbelt. These are3 column unstable fractures. Usually at upper lumbar and thoracolumbar junction. High association with solid organ trauma

Answer 78

Spectrum: subluxed - perched - locked UNILATERAL Usually from hyperflexion and rotation. Superior facet slides over inferior facet and gets locked. Unilateral is stable injury. Inverted hamburger sign on axial. BILATERAL Severe hyperflexion. Disruption of PLL. Dislocated vertebra displaced forward half AP diameter. Highly unstable and strongly associated with cord injury

Answer 79

Transverse cruciform ligament straps dens to anterior arch of C1. Distance between anterior arch and dens shouldnt be >5mm. Association with Downs and JRA Rotatory subluxation can occur in kids without fracture stuck in cock robin position. Looks like torticollis. Cannot happen in absence of fracture in adult.

Answer 80

Spondylolysis or adult isthmic spondylolisthesis. Caused by repetitive microtrauma related to hyperextension. Nearly always at L5/S1 90%. Typically pain is L5 radiculopathy caused by foraminal stenosis at L5S1.

Answer 81

Can be traumatic or congenital (seen in Downs). two popular methods for evaluating this, Powers ration and Harris Lines rule of 12.

Answer 82

Vertebral column divided into 3 vertical parallel columns. Instability suggested when all 3 or 2 contiguous columns are disrupted. Anterior column: ALL, ant 2/3 body Middle column: post 1/3 body and PLL Posterior column: posterior ligaments, pedicles, factes, lamina, spinous processes

Answer 83

``` Age >65 Parasthesias in extremities Dangerous mechanism Fall >3ft or 5 stairs Axial load to head High speed MVA Pedestrian vs car ```

Answer 84

``` Focal neurological deficit Midline spinal tenderness Altered level of consciousness Intoxication Distracting injury ```

Answer 85

``` Vertebral overriding >3mm Angulation >11 degrees Flexion tear drop Bilateral locked facets Odontoid fracture types 2 and 3 Two contiguous column fractures or 3 column Jeffersons Hangmans Atlanto-occipital and atlantoaxial dislocations ```

Answer 86

``` Extension tear drop in flexion Unilateral locked facet Odontoid fracture type 1 Single column vertebral fracture Clay shovelers Transverse process fracture ```

Answer 87

CENTRAL CORD Old lady with spondylosis or young person with bad extension injury Upper extremity deficit worse than lower ANTERIOR CORD Flexion injury. Immediate paralysis. Anterior cord damaged. Motor function and anterior column sensation (pain and temperature) gone. Dorsal column (vibration and proprioception) still intact. BROWN SEQUARD Rotation injury or penetrating trauma One side motor, other side sensory deficits POSTERIOR CORD Uncommon but can be seen in hyperextension. Proprioception gone

Answer 88

TYPE 1 By far most common 85%. Dural AVF Resukt of fistula between dorsal radiculomedullary arteries and radiculomedullary vein/coronal sinus with the dural nerve sleeve. Acquired and seen in old patients with progressive radiculomyopathy. Most common location thoracic spine. Gold standard is angiography. Swollen cord with high T2 signalin central cord with serpentine perimedullary flow voids TYPE 2 Intramedullary nidus from ant spinal artery or post spinal artery. Can have aneurysms and can bleed. Mos common rpesentation SAH. Associated with HHT and KTS TYPE 3 Juvenile, very rare, complex, bad prognosis TYPE 4 Intradural perimedullary with subtypes depending on arterial supply. Near conus

Answer 89

Congestive mylopathy associated with dural AVF. 45m with lwoer extremity weakness and sensory deficits. Increased T2 signal conus or lower T spine with associated prominent vessels. Venous HTN due to vascular malformation