Infections Flashcards
What is meningitis?
An infection of meninges
What are the characteristic features of meningitis?
Fever
Neck stiffness
Headache
What are other features of meningitis?
Photophobia
Nausea and vomiting
Cerebral dysfunction
Cranial nerve palsy
Seizures
Focal neurological deficits
Petechial skin rash
What investigations are done for meningitis?
Blood cultures- bacteriaemia
Lumbar puncture
No need for imaging if no contraindications to LP
What are the bacterial causes of meningitis?
Neisseria meningitidis
Strep. pneumonia
Haemophilus influenzae
E.coli
What are the CSF findings in bacterial meningitis?
Increased opening pressure
Neutrophil count
Reduced glucose
High protein
What are the viral causes of meningitis?
Enterovirus
Varicella zoster
Influenza
Mumps
Herpes simplex
HIV
What are the CSF findings of viral meningitis?
Normal/increased opening pressure
Lymphocyte count
Normal glucose
Slightly increased protein
What is encephalitis?
Inflammation of the brain itself
What are the clinical features of encephalitis?
Progressive headache
Fever
Progressive cerebral dysfunction
Seizures
Focal symptoms/signs
No photophobia or neck stiffness
What is more present in encephalitis than meningitis?
Neurological dysfunction
- Seizures
- Cranial nerve palsies
- Altered mental state
What are the types of brain abscess?
Brain abscess
Subdural empyema
What are the clinical features of cerebral abscess?
Fever
Headache
Focal symptoms: seizures, dysphasia, hemiparesis
Signs of raised ICP: papilledema, depressed conscious level
What is the management of cerebral abscess?
Surgical drainage
Penicillin
Metronidazole for anaerobes
What spirochete causes lyme disease?
Borrelia burdoferi
What is stage 1 Lyme disease?
Early localised infection
Erythema migrains
Flu like symptoms: fatigue, myalgia, headache, neck stiffness, fever, chills
What is stage 2 Lyme disease?
Early disseminated infection
Musculoskeletal and neurological involvement:
- Mononeuropathy
- Mononeuritis multiplex
- Painful radiculoneuropathy- most common
- Cranial neuropathy
- Myelitis
- Meningo-encephlitis
What is stage 3 Lyme disease?
Chronic infection
MS and neurological involvement
What is the treatment of Lyme disease?
Prolonged antibiotics
What are the features of poliomyelitis?
Enterovirus
Asymptomatic 99%
Anterior horn cell of LMNs -? asymmetrical flaccid paralysis
No sensory
What are the features of rabies?
Virus enters peripheral nerves and migrates to CNS
Paraesthesia at site of lesion
Ascending paralysis and encephalitis
What are the features of tetanus?
Infection with clostridium tetani
Toxins act at NMJ
Rigidity and spasm
What are the features of botulism?
Clostridium botulinum
Neurotoxin that blocks ACh release at synapses
Pure motor
Descending symmetrical flaccid paralysis
What are examples of post infective inflammatory syndromes?
CNS- Acute disseminated encephalomyelitis (ADEM)
PNS- Guillain Barre Syndrome (GBS)
