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Complications of suppurative OM

Terms in this set (25)

Spread of toxins and/or bacteria from the middle ear through a fistula produces diffuse perilymphatic labyrinthitis. Toxins may also reach the inner ear through the round window membrane to the inner ear.

Stages:
Typically four stages are described:
Diffuse serous stage (acute serous labyrinthitis):
This is an irritative stage characterized by:
1. Sensorineural hearing loss which is still reversible.
2. May be diplacusis (i.e. pure tone is heard differently in both ears).
3. Nystagmus, nausea, and vomiting. The nystagmus is toward the affected side.

Diffuse suppurative stage (acute suppurative labyrinthitis):
This is a destructive stage characterized by a complete loss of cochlear and vestibular function . Clinical features include:
1. Irreversible total sensorineural hearing loss.2. Nystagmus toward the normal ear, severe vertigo, nausea, and vomiting. 3. No reaction on caloric stimulation.

Fibrous stage (Chronic or healing labyrinthitis):

This stage is a healing stage characterized by fibroplastic proliferation within the perilymphatic space. Clinical features include:
1. Complete deafness.2. Mild dizziness.3. No reaction on caloric stimulation.

Osseous stage (labyrinthitis ossificans):
This is the final stage when the labyrinth becomes ossified. Clinical features include

1. Complete deafness.2. The residual vestibular symptoms depend upon the efficiency of vestibular compensation. When vestibular compensation is full all vestibular symptoms disappear.3. No reaction on caloric stimulation.

Treatment
Rapid treatment is essential in order to stop the infection at the reversible serous stage. The treatment includes:

Antibiotics.
Anti-vertiginous drugs
Treatment of ear infection: usually the cause is unsafe otitis media with cholesteatoma and therefore mastoidectomy is needed.
Drainage of the labyrinth (labyrinthectomy) is indicated if there is impending intracranial extension, e.g. meningitis.
Healed labyrinthitis requires no special treatment.
Definition:
Inflammation of leptomeninges (pia & arachinoid)

Pathology:
Occurs during acute exacerbation of chronic
unsafe middle ear infection.

Type III pneumococcus infection.

Two forms:
- Circumscribed meningitis: no bacteria in CSF.
- Generalized meningitis: bacteria are present in CSF
3 stages (serous, cellular, bacterial st)

Clinical picture:
- General symptoms and signs:
high fever, restlessness, irritability,
photophobia, and delirium.
- Signs of meningeal irritation:
1. Neck rigidity.
2. Positive Kernig's sign: difficulty to straighten the knee while the hip is flexed dt spasm of hamstring ms.
3. Positive Brudzinski's sign:
passive flexion of one leg results in a similar movement on the opposite side or
if the neck is passively flexed, flexion occurs in the hips and knees (head to leg/ leg to leg)


Clinical picture:
- Signs of increased intracranial pressure:
severe headache,
vomiting and
papilledema.

Terminal stage:
the delirium progresses to coma,
the reflexes become weak or absent,
cranial nerve palsies occur.

Diagnosis:
Lumbar puncture is diagnostic:
CSF is cloudy and
CSF pressure is increased.
Contains bacteria and many polymorphs.
Protein concentration is raised but
Glucose and chlorides are decreased.

Treatment:
a) general rx:
1. dark quiet room as pr is irritable
2. IV nutrition as pt is vomiting
3. dec CSF P by dehydrating agents (25% glucose or Mg sulfate enema)

b) sp Rx
1. medical rx:
- ABs: immediate then acc to culture
- surgical rx
mastoidectomy to control ear infection & to Ex perilymphatic fistula
Definition:
Thrombophlebitis of the lateral venous sinus.
2nd m/c cause of death f OM

Etiology:
It usually develops secondary to direct extension
from a perisinus abscess due to unsafe otitis
media with cholesteatoma.

Pathology:
Inflammation of the walls of the sinus causes the formation of a mural thrombus which obstructs the lumen of the sinus.
Then become infected intra-sinus abscess.
Infected emboli are shed from the infected thrombus causing pyemia.
When the organisms reach the blood stream septicemia develops.
Progression of infection may lead to
cavernous sinus thrombosis or
cerebellar brain abscess.

Clinical picture:
Signs of blood invasion:
- mcq** hectic (spiking) intermittent fever with rigors and chills due to the showers of septic emboli. D.D: malaria.
persistent fever (septicemia).
- mcq **Positive Greissinger's sign which is edema and tenderness over the area of the mastoid emissary vein.
- Signs of increased intracranial pressure: headache, vomiting, and papilledema.
When the clot extends to the jugular vein, the vein (int jugular vein) will be felt in the neck as a tender cord.

Diagnosis:
- CT scan with contrast=> filling defect
- MRI, MRA, MRV
- Angiography, venography
- Blood cultures is positive during the febrile phase.
- mcq** Queckentedt's test (Tobey-Ayer's test) : CSF P measurement to detect obstruction of lat-sinus by compression of IJV.

Treatment:
- Medical:
systemic Antibiotics and supportive treatment.
Anticoagulants
- Surgical:
Mastoidectomy with exposure of the affected sinus (lat sinus) -> needle aspiration-> and the intra-sinus abscess is drained.

Ligation of the internal jugular vein distal to the facial vein is indicated in recurrent embolism.
Definition:
Localized suppurative inflm in the brain substance.

It is most lethal complication of suppurative OM

Incidence:
50% is Otogenic brain abscess
It is more common in males especially between 10 - 30 years of age.

Pathology:
Site:
Temporal lobe or
Less frequently, in the cerebellum. (more dangerous)

4 stages:
1. Stage of encephalitis: brain tissue inflammation
2. Stage of localization (latent stage): small cavities filled with pus
3. Stage of acute abscess (Manifest stage)
Rupture spontaneously
Compress other brain centers
4. Stage of chronic abscess:
Stationary, low virulent organism, thick wall

Clinical picture:
- Stage of invasion (encephalitis):
fever, headache, delirium, and
Signs of meningeal irritation.
- Latent stage (stage of localization):
Minimum symptoms ,mild headache
The patient may be lethargic & irritable.

- Manifest stage (acute abscess):
a) Symptoms and signs of increased intracranial pressure:
Severe headache.
Projectile vomiting (no nausea).
Papilledema.

b) Characteristic signs and symptoms of brain abscess:
Marked toxemia and loss of appetite.
Slow pulse.
Subnormal temperature.
Delirium and lethargy.
Localizing signs:
. Temporal lobe abscess:
Aphasia (left-sided lesions of Brochas area)
Hemianopia (optic radiation).
Hemiplegia or hemiparesis. (1ry motor area)
Uncinate: olfactory hallucinations.
. Cerebellar abscess:
Homolateral hypotonia.
Ataxia
Intention tremors (finger-to-nose test).
Dysdiadochokinesis.
Positive Romberg's sign.
Wide based drunken gait
Central nystagmus

Terminal stage: 4th stage
Brain abscess unless treated usually ends by death either due to:
Coning of the brain stem into foramen magnum=> resp center=> resp arrest ,
Rupture of the abscess.

Chronic abscess:
Headache
Mental changes

Diagnosis:
CT scans.
MRI

Treatment:
- Medical:
Systemic antibiotics.
Measure to decrease intracranial pressure.
- Surgical:
Neurosurgical drainage of the abscess or excision.
Aspiration via burr hole.
Appropriate mastoidectomy operation after subsidence of the acute stage.