Pathology of the NS Flashcards
What is Meningitis ?
Inflammation/infection of the meninges
What is Encephalitis ?
Infection/inflammation of the brain
What is Myelitis ?
Infection/inflammation of the spinal cord
How would a patient with Meningitis present ?
- Fever
- Headache
- Stiff neck
- Photophobia
- Petechiae rash (Meningococcus)
- N/V
- Seizures
What are the main bacterial causes of Meningitis and who do they typically effect ?
- Neisseria meningitis (meningococcus) - Young adults and children
- Group B Strep - Neonates
- E. coli - Neonates
- Strep. pneumoniae (pneumococcus) - Adults
What are the main viral causes of Meningitis ?
- HSV
- Enteroviruses (Polio)
How does a patient present with Encephalitis ?
- Flu-prodrome
- Progressive headache - Altered conscious levels
- Fever
- Abnormal behaviour
- Seizures
What causes Encephalitis ?
It is usually viral e.g. HSV, Aborviruses. Can be autoimmune.
How do you investigate Meningitis ?
- Bloods culture/cell count
- CT/MRI
- LP - CSF culture and microscopy
- If viral suspected do PCR
How to investigate Encephalitis ?
- Blood culture/cell count - In autoimmune look for Anti VGKC and Anti NMDA
- CT/MRI
- LP
When do you not perform a LP ?
- Focal signs
- Altered conscious level
- Papilloedema
What CSF findings are found in bacterial Meningitis ?
- Low sugar
- High protein
- High levels of neutrophils
- Opening pressure is high
What CSF findings are found in viral Meningitis ?
- Normal sugar
- Normal protein
- High levels of lymphocytes
- Opening pressure is normal
How is HSV treated ?
Acyclovir
How are enteroviruses transmitted ?
Faecal-oral route
How are Arboviruses transmitted ?
By vector from non-human host. Some are preventable by immunisation.
How do you treat a patient with bacterial Meningitis ?
IV Ceftriaxone
Corticosteroids
How do you treat a patient with viral Meningitis ?
Anti-virals Bed rest Hydrate Analgesics Corticosteroids to reduce inflammation
How would a patient present who has an abscess ?
- Fever
- Headache
- Nausea and vomiting
- Papilloedema
- Seizures
- Altered conscious level
How do you investigate a brain abscess ?
- CT/MRI
- Blood cultures
- Biopsy
How do you treat a brain abscess ?
- Drainage
- High dose IV antibiotics (Penicillin for strep and metronidazole for anaerobes)
What brain diseases can HIV cause (3) ?
- Meningitis
- Brain abscesses
- Dementia
What is seen in patients with HIV in bloods ?
Low CD4 count
What infective agents usually are found in patients with HIV ?
- Crypotococcus neoformans
- CMV
- Toxoplasma gondri
How do you investigate HIV infections ?
- PCR for CMV
- Crypotococcal antigen
- Toxoplasmosis serology
What are the two main Spirochaete’s ?
Borrelia burgdorferi (Lymes disease) Treponema Pallidum (Neurosyphilis)
How does Lyme’s disease present ?
Rash at site of tick bite, flu symptoms, one or more organs affected. Period of latency then chronic infection.
What investigations are done in Lyme’s disease ?
- MRI
- CSF lymphocytosis
- EMG
How do you treat Lyme’s disease ?
IV Ceftriaxone
Doxycycline (oral)
How do you investigate Syphilis ?
- Antibody tests
- CSF lymphoyctosis
How do you treat Syphilis ?
High dose penicillin
How does Polio usually present ?
Patients are asymptomatic and only 1% has paralysis
Can Polio be prevented ?
Vaccination - Polio virus given combined with other antigens
How does Rabies present ?
Disease of the PNS. Paraesthesia at the site of lesion. Paralysis starts distally and work way upwards.
How is Rabies investigated ?
PCR and serology
How is Rabies prevented ?
Rabies immunisation with killed vaccine.
How is rabies treated ?
Person given immunoglobulins and immunisation. Wound must be cleaned.
How does Tetanus present ?
Rigitidy and spasm
What is Tetanus ?
Clostridium Tetani anaerobic gram +ve bacillus, spore forming. Acts at the neuromuscular junction and block inhibition of motor neurones.
How is Tetanus treated ?
Immunoglobulins and high dose penicillin. Immunisation can be given to those at risk.
What is Botulism ?
Clostridium Botulinum anaerobic gram +ve bacillus. Neurotoxin binds to presynaptic membrane and prevent Ach release.
How does a patient present with Botulism ?
Descending paralysis
How do you investigate Botulism ?
- Serology
- Culture from wound
How do you treat Botulism
Penicillin and metronidazole. Antitoxins.