History
Spinal epidural abscess
Early presentations may be subtle, and diagnosis may be difficult, if not impossible, at early stages.
History of fever is often but not invariably present.
Localized back pain may be present.
If present, neurologic deficit is consistent with a spinal cord syndrome.
History may suggest a source or cause of infection (eg, soft tissue infection, intravenous drug abuse, indwelling catheters, recent epidural injections, neurosurgical procedures or other instrumentation).
Duration of symptoms is typically a few days but may extend over weeks. Symptom onset may also be abrupt.
Radicular pain consistent with nerve root irritation may confound evaluation, particularly if the pain occurs in the abdomen or the chest.
Progressive sensory disturbances in the extremities, weakness, and incontinence suggest progression to spinal cord involvement.
An immunosuppressive condition, such as diabetes, alcoholism, HIV infection, or chronic liver or kidney disease, is often present.
Subdural empyema
Headaches may be initially unilateral but then become generalized.
Fever and vomiting may be present.
Focal or generalized seizures may be present.
Tempo of clinical course usually is fulminant with rapid deterioration.
Unusual indolent courses may follow neurosurgical procedures.
A history of recent sinusitis or otitis media may be present.
Antibiotic therapy may lessen systemic symptoms.
Physical
Both spinal epidural abscess and subdural empyema may manifest generalized signs and symptoms of infection such as fever, sepsis, or septic shock.
Spinal epidural abscess
The classic triad of spinal epidural abscess includes spinal pain, fever, and neurological deficits, but this is seen in only 10%-15% of cases. [6]
Localized tenderness to percussion or palpation over the involved region may or may not be present.
Signs of spinal cord dysfunction, such as loss of sphincter tone, sensory loss, or localized motor weakness are late findings.
Reflexes may vary from hypoactive or absent to brisk and spastic.
An abnormal postvoiding residual volume may be a sign of spinal cord disfunction.
Subdural empyema
The classic presentation of subdural empyema is an acute febrile illness accompanied by progressive neurological deterioration. Focal neurologic deficit, such as hemiparesis or aphasia, or focal seizures may be present, in addition to signs of meningeal irritation.
Altered mental status is present in most patients.
Papilledema is absent in most patients, reflecting a short duration of increased intracranial pressure.
Causes
Spinal epidural abscess
Most cases arise from hematogenous seeding of the epidural space from a distant source of infection.
Another etiology is extension of infection from adjacent vertebral osteomyelitis or discitis.
Penetrating trauma, recent neurosurgical procedures, or recent epidural injections or catheter placements are other causes.
Staphylococcus aureus is the most frequent bacteriologic cause, with methicillin-resistant S aureus (MRSA) being increasingly reported. [13]
Subdural empyema
Most cases are extensions of infections from the paranasal sinuses.
Otitis media or mastoiditis also may extend into the subdural space.
Recent neurosurgical procedures and penetrating trauma cause other cases.
Hematogenous spread of infection from a pulmonary source also has been reported.
Complications
Spinal epidural abscess may impair spinal cord function through compression, although current thinking is that thrombosis of vertebral vessels with secondary infarction of the cord may be the mechanism of injury.
Subdural empyema may precipitate cerebral venous thrombosis or cause increased intracranial pressure, resulting in decreased cerebral perfusion and diffuse cerebral edema. Seizures are common.
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Spinal epidural abscess with cord edema and compression. Abscess extends into paravertebral tissues.
