Acute infections of central nervous system

Types of acute CNS infections

Meningitis - infections of the membranes surrounding

Mortality

The mortality rate for viral meningitis is less than 1%.
The

Causes of CNS infections

Routes of CNS infections

Common symptoms

Meningitis

Meningitis - inflammation of the meninges, the membranes covering the brain and spinal cord.

Common causes of meningitis

Bacterial meningitis:
Neisseria meningitidis (meningococcus)
Streptococcus pneumoniae (pneumococcus)
Haemophilus influenzae b

Bacterial pathogens by age

< 3 month
Streptococcus agalactiae,
Enterococcus,
Staphylococcus aureus,
Salmonella,

Bacterial pathogens by age

3 mo – 3 yr
Neisseria meningitidis,
Streptococcus pneumoniae,

Meningitis

Clinical Picture

Meningeal posture

Diagnosis

Meningitis. CSF profiles

Cerebrospinal fluid

Complications of bacterial meningitis

Early
Cerebral edema
Hydrocephalus
Hemorrhage
Ventriculitis
Cerebral infarction
Necrotizing lesions
Late
Hearing loss
Physical and mental retardation
Epilepsy

Hydrocephalus

Ventriculitis

External shunt

Pus from ventricles

Haemophilus influenzae туре b (Hib)

Haemophilus influenzae is a pleomorphic gram-negative coccobacillus

Pneumococcal infection

Streptococcus pneumoniae (pneumococci) are lancet-shaped, gram-positive diplococci. At least 90

Meningococcal infection

Etiology:
Neisseria meningitidis
Gram (-) diplococci
13 serogroups
Most frequent: A, B, C,

Clinical forms of MI

Localized forms:
Nasopharyngitis;
Asymptomatic carriage.
Generalized forms:
Meningitis;
Meningococccemia
Rare forms (carditis, arthritis, choroiditis)

Meningococcal Nasopharyngitis

Nonspecific clinical picture.
Diagnosis made by bacteriological tests

Hemorrhagic rash (meningococcemia)

Tumbler test for hemorrhagic rash

Hemorrhagic rash (meningococcemia)

Cyanosis (meningococcemia)

Brain damage (meningococcemia)

Visceral hemorrhagic lesions

Suprarenal glands hemorrhagic lesion

Marmoreal skin’s color (shock)

Treatment

Viral meningitis – usually symptomatic
Bacterial meningitis – antibacterial therapy
Fungal meningitis –

Bacterial meningitis. Antibacterial treatment

Undefined etiology – empirical treatment depends on suspected

Defined etiology

Defined etiology

Encephalitis

Encephalitis - inflammation of the brain tissue

Etiology

Enteroviruses,
Herpes simplex virus types 1 and 2,
Human herpes viruses types 3

Encephalitis

Clinical Picture

Encephalitis

Signs:
fever,
headache,
chills,
sweats,
malaise;
focal neurological deficits (paresis, aphasia),
alteration of mental status,
low consciousness,
seizures.

Brain scanning - MRI and CT imaging

Encephalitis. Brain lesion

Treatment

Etiology
HSV ½, VZV, EBV Acyclovir
CMV Gancyclovir
Other Mainly supportive

Poliomyelitis

Etiology
Poliovirus is an RNA virus that belong to Enterovirus family. Three

Clinical forms

Inapparent infection (usually asymptomatic),
Abortive disease (frequently sore throat and

Paralytic disease

Virus produces destruction of the motor neurons in the anterior

Paralytic disease

Spinal paralytic poliomyelitis: paralysis or paresis of trunk muscles or