CNS infections

Question 1

give a differential for fever and altered mental status

Answer 1

• Encephalitis
• Meningitis
• Meningoencephalitis
• Encephalomyelitis
• Severe sepsis syndrome due to infection elsewhere

Question 2

for viral meningitis give:

the most common time for it to occur,

the most common cause

the diagnosis

and management

Answer 2

• Late summer/ autumn
• Enteroviruses e.g ECHO virus
• Diagnosis- viral stool culture, throat swab and CSF PCR
• Treatment is generally supportive as self limiting

Question 3

give the clinical features of encephalitis

Answer 3

• Insidous onset; sometimes sudden
• Meningismus
• Stupor, coma
• Seizures, partial paralysis
• Confusion, psychosis
• Speech, memory symptoms

Question 4

what are the most common causes of encephalitis and how are they treated?

Answer 4

• Herpes simplex; recognition, diagnosis, RAPID [< 6 HOURS OF ADMISSION] treatment (aciclovir iv high doses)
• Varicella zoster (history of shingles)- high dose aciclovir

Question 5

what are the common causes of bacterial meningitis by age?

Answer 5

•Neonates: listeria, group B streptococci, E. coli

–H. influenzae type b is the most common cause of meningitis in children under 4 years old.

• 10 to 21: meningococcal
• 21 onward: pneumococcal >meningococcal
• Elderly: pneumococcal>listeria

Question 6

what is the antibiotic of choice against listeria monocytogenes?

Answer 6

amoxicillin/ ampicillin

Question 7

what are the 3 main signs of bacterial meningitis?

Answer 7

fever,

stiff neck,

alteration in consciousness

Question 8

list all the signs and sympoms of meningitis

Answer 8

Headache

Vomiting

Pyrexia

Neck stiffness

Photophobia

Lethargy

Confusion

Rash

Question 9

what would be the protein, glucose and cell count for viral/bacterial and tb in the CSF in a paitent with meningitis?

Answer 9

Question 10

for acute adult bacterial meningitis admitting doctor should…..

Answer 10

take blood for culture and coagulation screen

give the treatment as outlined in ‘Initial therapy before pathogens are identified’ vide infra, and immediately thereafter

take a throat swab which should be plated as soon as practicable by the microbiologist

disrupt and swab or aspirate any petechial or purpuric skin lesions for microscopy and culture

Question 11

who should go for ct scan prior to lumbar puncture?

Answer 11

Question 12

who should be gievn a lumbar puncture?

Answer 12

All adult patients with suspected meningitis except when a clear contraindication exists or of there is a confident clinical diagnosis of meningococcal infection with a typical meningococcal rash

Question 13

what are the antibiotics used for meningitis

Answer 13

1. EMPIRIC ANTIBIOTIC THERAPY

IV CEFTRIAXONE 2g bd

ADD IV AMPICILLIN/AMOXICILLIN 2g qds IF LISTERIA SUSPECTED

2. PENICILLIN ALLERGY (RASH OR ANAPHYLAXIS)

If there is a clear history of anaphylaxis to beta-lactams give chloramphenicol iv 25 mg/kg 6-hourly with vancomycin iv 500 mg 6-hourly or 1g 12-hourly.

If listeria suspected and penicillin allergy co-trimoxazole alone has been used successfully for this infection.

Question 14

describe management algorithm

Answer 14