Flashcards in Brain accesses and other infections Deck (17):
What is a brain abcess?
Focal supportive process within brain parenchyma (i.e. pus in substance of the brain)
What are the main cause of brain accesses?
Usually mixed bacterial (polymicrobria)
Streptococci e.g. streptococcus anginosus (pus forming)
Gram negative enteric bacteria e.g. E coli, pseudomonas
Other e.g. fungi, TB
What are the mechanisms by which brain accesses can come about?
Direct spread from "continuous" suppurative focus e.g. ear***, sinus, teeth
Haematogenous spread from distant sources e.g. endocarditis, brochioectasis
Trauma e.g. skull fracture
Cryptogenic (no focus e.g. TB)
What are the clinical presentations of brain accesses?
- Focal Neurological defects (30-50%)
- confusion/reduced GCS
- Fever (less than 50%)
- Neck stiffness
How do you manage brain accesses?
Brain drainage - reduce IC pressure, enhance diagnosis and treatment i.e. focus antibiotics
Give some examples of antibiotics that will penetrate intracranial pus?
- Beta lactams e.g. benzyl Penecillin
- Cephasporins e.g Cefuroxime, cefotaxime and ceftazidime (3rd gen good against pseudomonas - otitis media)
What are sinugenic and odontogenic accesses?
Come from SINUSES and TEETH
What are orogenic accesses?
Comes from EAR
What are the complications of brain accesses?
- Increased IC pressure
- Mass effect
- Rupture, causing ventriculitis
What is a subdural empyema?
Infection between dura and arachnoid mater
What is the pathogenesis of subdural empyema?
Spread of infection from SINUSES (Usually), middle ear, mastoid or distant site (haematogenous)
Also following surgery e.g. staph aureus
What are the causes of subdural empyema?
Polymicrobrial - depends on pathogenesis and location
What is the clinical presentation of subdural empyema?
Focal neurological Defects *
What is the management of subdural empyema?
Urgent surgical drainage of pus, antimicrobial agents
What are ventriculoperitoneal (VP) shunts and External ventricular drains (EVD)?
Devices that monitor IC pressure and drain excess CSF
What is the relevance for EVD and VP shunts?
Can become infected causing ventriculitis