13 Pathogenesis Aditus Blockage Failure of drainage Stasis of secretions Hyperemic decalcification Resorption of bony septa of air cells Coalescence of small air cells to form cavity Empyema of mastoid cavity
15 Clinical Features & Investigation Otorrhoea > 2 weeks, otalgia & deafnessMastoid reservoir sign: pus fills up on moppingSagging of postero-superior canal wall due to peri-osteitis of bony wall b/w antrum & posterior E.A.C.Ironed out appearance of skin over mastoid due to thickened periosteumMastoid tenderness presentMastoid cavity in X-ray & CT scan
21 Mastoiditis Furunculosis H/o otitis media+-DeafnessPosition of pinnaDown + outward + forwardForwardPost-aural grooveDeepenedObliteratedEar dischargeMuco-purulentSerous / purulentSagging of EAC wallTM congestionTendernessMastoidTragalPost-aural lymph nodeX-ray MastoidCoalescence of cells + cavityNormal
22 Treatment Urgent hospital admission Broad spectrum I.V. antibiotics No response to medical treatment in 48 hrs Development of new complication Presence of sub-periosteal abscessMyringotomy to drain out painful pusIncision drainage of sub-periosteal abscessCortical Mastoidectomy
32 D/D of Bezold’s abscess Suppurative lymphadenopathy of upper deep cervical lymph nodePara-pharyngeal abscessParotid tail abscessInfected branchial cystInternal jugular vein thrombosis
33 Luc: swelling in external auditory canal Zygomatic: swelling antero-superior to pinna +upper eyelid oedemaRetro-mastoid: swelling over occipital bone(? Citelli’s abscess)Parapharyngeal & Retropharyngeal: due to spreadof pus along Eustachian tube
51 Facial nerve paralysis Within 1st wk: due to nerve sheath edemaAfter 2 wks: due to bone erosionLower motor neuron palsyCommon in tubercular otitis mediaTreatment:Modified Radical MastoidectomyFacial nerve decompression seldom required
60 Clinical Features of ed I.C.T. Seen more in cerebellar abscessSevere persistent headache, worse in morningProjectile vomitingBlurring of vision & PapilloedemaLethargy drowsiness confusion comaBradycardiaSubnormal temperature
72 Spread of thrombusProximal: 1. To superior sagittal sinus via torcula Hirophili hydrocephalus2. To cavernous sinus proptosis3. To mastoid emissary vein Griesinger’s signDistal: To internal jugular vein & subclavian vein pulmonary thrombo-embolism & septicaemia
73 Clinical Features Remittent high fever with rigors (picket fence) Pitting edema over retro-mastoid area & occipital bone due to mastoid emissary vein thrombosis (Griesinger’s sign)Tenderness along Internal Jugular VeinHeadacheAnaemia
75 Picket fence fever High fever, swinging type Chills precedes fever Temperature subsides with sweatingEach fever spike due to release of fresh septic embolus
76 Special TestsQueckenstedt or Tobey-Ayer test: compression of I.J.V. rapid rise of C.S.F. pressure (50 – 100 mm water rapid fall on release of compression. In L.S.T. no rise / rise by only 10 – 20 mm water.Lillie – Crowe - Beck test: pressure on I.J.V. on normal side engorgement of retinal veins + papilloedema seen in fundoscopy due to L.S.T. on opposite side.
79 Investigations Lumbar puncture: to rule out meningitis CT brain with contrast: Delta sign orMRI brain with contrast: Empty triangle signMR angiographyBlood cultureCulture & sensitivity of ear dischargePeripheral blood smear: to rule out malaria
88 Collection of pus b/w dura & arachnoid by erosion of bone & dura mater or by retrograde thrombophlebitisDue to rapid spread of pus, symptoms of raised intra-cranial tension & meningeal irritation develop quicklyCT scan brain shows subdural abscessTx: I.V. Ceftriaxone + Metronidazole + Gentamicin Burr hole evacuation of pus Radical mastoidectomy after pt becomes stable
93 Brain FungusProlapse of brain into middle ear cavity / mastoid cavity due to erosion of dural plate.Common in pre-antibiotic era. Rarely seen now in resistant infections.Diagnosis: C.T. scan temporal bone.Treatment: Removal of necrotic tissue, replacement of healthy prolapsed brain into cranial cavity & repair of bone defect.