Download Intracranial Complications Of Otitis media

Intracranial
Complications Of
Otitis media
Intracranial Complications are :
• Extradural Abscess
• Subdural Abscess
• Meningitis
• Brain abscess
• Lateral Sinus
Thrombosis
• Otitic Hydrocephalus
Pathways of spread of infection
• DIRECT BONE EROSION
• VENOUS THROMBOPHLEBITIS
• PREFORMED PATHWAYS
• Congenital dehiscence e.g.-in bony facial canal.
• Patent sutures e.g. petro squamous suture.
• Previous skull fractures
• surgical defects –stapedectomy ,fenestration
procedures and mastoidectomy with exposure of the
dura.
• Through oval and round windows.
• Infection from labyrinth travel along iam ,aqd of
vestibule
Extradural Abscess
• It is defined as the
collection of pus
between the dura and
the bone of middle and
or posterior cranial
fossa
• Dura in contact with
granulation or
cholesteatoma gets
thickened
Clinical Picture :
• HEADACHE,MALAISE.
• Ear pain, discharge
• Temperature – low grade fever
• Relief of headache with flow of pus from ear
Investigations
• CT scan : helps in identifying patients with
extra dural abscess presenting with raised
intracranial pressure
Management
• Surgical Exploration and Evacuation of pus.
• Bone has to be removed around the diseased
dura leaving a cuff of healthy dura around with
no bony covering.
• IV Antibiotics
Subdural abscess
• Intracranial focal
collection of purulent
material located
between the
duramater and the
arachnoid mater
Symptoms:
• Meningeal irritation
• Cortical venous thrombophlebitis – aphasia,
hemiplegia, hemianopia
• Raised intracranial tension
Investigations
• Elevated ESR
• Blood Culture
• Lumbar puncture is not attempted because of the
chance of cerebral herniation from increased
intracranial pressure
• CT Scan: shows enhancement of the meninges
around the abscess
• MRI Scan
Treatment
• Surgical drainage through frontal burr holes or
craniotomy is required
• IV Antibiotics : 20-24 million units of pencillin
with 3rd gen cephalosporin with metronidazole
• Mastoid exploration
Meningitis
• Inflammation of the pia-arachnoid and the
cerebrospinal fluid in the subarachnoid space
• Most common intracranial complication
Pathogenesis
• Hematogenous Spread : Hematogenous
dissemination during active AOM
• Bone erosion or retrograde thrombophlebitis
Symptoms
• Fever
• Headache
• Nuchal rigidity
• Altered level of consciousness
• Photophobia
• Vomiting
Signs
• Neck stiffness
• Brudzinki sign
• Kernig sign
Investigations
Lumbar Puncture
• CT/MRI Brain
• TREATMENT
• IV antibiotics
• Dexamethasone-adjunctive to reduce neurological
sequelae ( b/l h.loss)
Brain Abscess
• Focal supparative infection occurring within the brain
parenchyma
• It is most lethal complication of suppurative otitis
media
• Incidence:
• – 50% is Otogenic brain abscess
• – It is more common in males especially
• between 10 – 30 years of age
•
Site
• Temporal lobe
• Less frequently, in the cerebellum. (more
dangerous)
Bacteriology
• Aerobic – pyogenic staphylococci, strptococci,
pneumococci, proteus, pseudomonas, E coli
• Anaerobic – Peptostreptococcus, B fragilis
Pathology
• 4 stages
• 1. Stage of invasion (
initial encephalitis)
• 2. Stage of localisation (
latent abscess)
• 3. Stage of enlargement (
manifest abscess)
• 4. Stage of termination (
rupture of abscess)
Symptoms and signs
• Headache
• Subnormal temperature
• Malaise
• Vomiting
• Papilloedema
• Drowsiness
• Stupor
• Coma
• Death
Temporal lobe abscess
• Nominal aphasia
• Homonymous hemianopia
• Contralateral motor paralysis
• Uncinate fits
Cerebellar abscess
• Headache
• Spontaneous nystagmus
• Ipsilateral hypotonia , ataxia
• Past pointing, intention tremors
• Dysdiadokokinesia
Diagnosis
• MRI scan: Ring enhancing lesion
• CT Scan
• Lumbar puncture should not be performed in
fear of herniation
• Raised ESR and peripheral leukocytosis
Treatment
• High dose IV antibiotics – Chloramphenicol, 3rd
gen cephalosporins
Metronidazole, gentamicin
• Aspiration and drainage of abscess contents
• IV dexamethasone
• Large abscess may require burr hole followed
by radical or modified radical mastoidectomy
Lateral Sinus Thrombophlebitis
• Inflammation of the sigmoid sinus resulting in
the formation of thrombus in the sigmoid
sinus
• Common Organism : Streptococcus
,Pneumococcus Type 3
Symptoms
• High swinging fever of 39-40 degrees (picket fence
type)
• Headache
• Neck pain
• Projectile vomiting
• Anaemia
Signs
• Ear discharge
• Mastoid tenderness
• Grisenger Sign : pitting oedema over the occipital
region, well behind mastoid process due to clotting
behind mastoid emissary veins.
• Tenderness and oedema of neck
• Raised ICP-papilloedema and visual loss.
(chemosis, proptosis if cavernous sinus is involved)
Queckenstedt or Tobey- Ayer test
• It involves measurement of CSF pressure and
observing the changes on compression of one or
both IJVs by fingers on the neck.
• In normal –comparison of each vein is followed by
rapid rise of CSF (50-100 mmHg)above normal.
There is an equally rapid fall on releasing
CROWE- BECK TEST
• Pressure on the jugular vein on the healthy side
produces engorgement of retinal veins ( seen by
ophthalmoscopy) and supraorbital veins.
Engorgement of veins subside on release of
pressure.
Investigations
• Blood culture
• CSF examination
• CT scan
• MRI - Gadolinium enhancement may show
delta sign.
Treatment
• IV Antibiotics :ampicillin , chloramphenicol, a cephalosporin
and an aminoglycoside.
• IV fluids
• Antiepileptics if necessary
• Anticoagulants only if thrombus reaches cavernous sinus.in
c/c om
Surgery
• Mastoidectomy followed by sinus exploration
• Ligation of Internal jugular vein
Otitic Hydrocephalus
• Raised Intracranial pressure during or
following middle ear infection with normal CSF
findings
• Pathogenesis
Retrograde extension of thrombophlebitis from
sigmoid sinus to superior saggital sinus
Blockage of arachnoid villi
CSF decreased absorption /increased secretion
Raised CSF pressure
• CLINICAL FEATURES
• Headache
• Drowsiness
• Blurred vision
• Nausea
• Vomiting
• Diplopia
• Clinical exmn – papilloedema, drowsiness
• Diagnosis
• CT
• Treatment
• Steroids
• Diuretics
• Hyperosmolar dehydrating agents
• Long term thecoperitoneal shunting is needed.
• PROGNOSIS- good Rx require weeks/months
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