Infections of the Nervous System Flashcards
What is meningitis?
Inflammation and infection of meninges
What are the common symptoms of meningitis?
Headache Fever Neck stiffness Altered mental state Photophobia Nausea/ vomiting Seizures Petechial skin rash
What are the bacterial causes of meningitis?
Meningococcus
Pneumococcus
What is the viral cause of meningitis?
Enterovirus
What is encephalitis?
Inflammation and infection of brain substances
What are the clinical symptoms of encephalitis?
Progressive headache Meningism Confusion Abnormal behaviour Memory disturbance Depressed conscious level Seizures
What are the investigations for meningitis?
Blood cultures
Lumbar puncture
What are the investigations for encephalitis?
Blood cultures
CT/MRI
Lumbar puncture
EEG
What are the antibodies associated with auto-immune encephalitis?
Anti-voltage gated potassium channel
Anti-NMDA
What are the CSF findings for bacterial meningitis?
Opening pressure increased
High cell count, mainly neutrophils
Glucose reduced or zero
High protein
What are the csf findings for viral meningitis or encephalitis?
Opening pressure normal or increased
Cell count high, mainly lymphocytes
Glucose normal
Protein slightly increased
What is the specific investigation for herpes simplex encephalitis?
Lab diagnosis by PCR of CSF for viral DNA
What is the treatment for herpes simplex encephalitis?
Aciclovir
Where is the herpes simplex virus found latent after primary infection?
Trigeminal and sacral ganglion
What is the significance of arbovirus encephalitides?
Relevant to travel history, common in sub/tropics
What is a brain abscess?
Localized area of pus within the brain
What are the clinical features of a brain abscess or empyema?
Fever Headache Seizures Hemiparesis Dysphasia Signs of raised ICP (depressed conscious level, papilloedema)
What are the causes of brain abscess and empyema?
Penetrating head injury
Spread from adjacent infection
Blood borne infection (bacterial endocarditis)
What are the investigations for brain abscess or empyema?
CT/MRI
Investigate source
Blood cultures
Biopsy/ drainage of pus
What is the management of a brain abscess?
Surgical drainage
Penicillin or ceftriaxone to cover streps
Metronidazole for anaerobes
What are the common organisms responsible for brain abscess?
Strep anginosus Strep intermedius Strep constellatus Prevotella Bacteroides
What are the HIV indicator illnesses associated with the brain?
Cerebral toxoplasmosis Aseptic meningitis/ encephalitis Primary cerebral lymphoma Cerebral abscess Dementia Cryptococcal meningitis
What are the diagnostics for HIV indicator illnesses?
India ink, cryptococcal antigen Toxoplasmosis serology (IgG) JC virus PCR CMV PCR HIV PCR
What are the investigations for Lyme disease?
Range of serological tests CSF lymphocytosis PCR of CSF MRI brain/spine Nerve condition studies
What is the treatment for Lyme disease?
Prolonged antibiotic treatment (IV ceftriaxone, oral doxycycline)
What are the symptoms of Lyme disease?
Fatigue Myalgia Headache Neck stiffness Fever, chills
What are the clinical findings for neurosyphilis?
CSF lymphocytes increased
Evidence of intrathecal antibody production
What is the treatment for neurosyphilis?
High dose penicillin
What part of the CNS does poliomyelitis infect?
Anterior horn cells of lower motor neurones
What are the clinical signs of poliomyelitis?
Asymmetric, flaccid paralysis in legs
What is the post-exposure treatment for rabies?
Wash wound
Give active rabies immunisation
Give human rabies immunoglobulin
What is the infection associated with tetanus?
Clostridium tetani
anaerobic gram positive bacillus, spore forming
What is the effect of tetanus?
Blocks inhibition of motor neurones causing rigidity and spasm
What causes botulism?
Clostridium botulinum
What is the clinical presentation of botulism?
Descending symmetrical flaccid paralysis
Respiratory failure
Autonomic dysfunction
What are the investigations for botulism?
Nerve conduction studies
Culture from derided wound
What is the treatment for botulism?
Anti-toxin
Penicillin/ metronidazole
Radical wound debridment
What are the clinical features of sporadic Creutzfeldt-Jakob disease?
Early behavioural abnormalities
Rapidly progressive dementia
Myoclonus
