Infectious disorders of the CNS

Blood brain barrier function

Prevents infectious agents from entering CNS

Blood brain barrier breach

Occurs when endothelial cells respond to environmental changes

CNS immune limitation

Low antibodies low white blood cells no lymphatic system

Meningitis definition

Inflammation of meninges of brain or spinal cord

Meningitis complication

Infection spreads to cortex thrombosis infarction hydrocephalus

Meningitis cardinal symptom

Headache

Meningitis high risk populations

Infants elderly immunocompromised

Meningitis environmental risk

Close living conditions such as dorms

Meningitis medical risk

HIV chemotherapy transplant corticosteroids

Meningitis structural risk

Skull fracture ear infection or meningeal penetration

Aseptic meningitis cause

Viral or fungal infection

Aseptic meningitis common viruses

Herpes simplex enteroviruses Epstein Barr

Aseptic meningitis onset

Days to weeks after exposure

Recurrent aseptic meningitis

Two or more episodes with symptom free periods

Chronic aseptic meningitis

Waxing and waning symptoms

Bacterial meningitis source

Upper respiratory tract or birth canal

Neonatal meningitis organisms

Group B strep E coli listeria

Infant meningitis organisms

Hib pneumococcus meningococcus

Bacterial meningitis complication

May cause axonal damage and lasting deficits

Tuberculous meningitis cause

Mycobacterium tuberculosis

Tuberculous meningitis spread

Rupture of tubercle into subarachnoid space

Tuberculous meningitis effect

Significant inflammation and neurologic involvement

Meningitis early symptoms

Fever headache stiff neck lumbar pain

Meningitis progression sign

Positive Brudzinski sign

Meningitis late signs

Seizures coma vomiting papilledema cranial nerve deficits

Kernig sign

Pain with knee extension when hip flexed

Brudzinski sign

Neck flexion causes hip and knee flexion

Meningitis diagnosis

Lumbar puncture

Meningitis imaging

CT for infarction or abscess Xray to rule out other pathology

Bacterial meningitis CSF

Low glucose high white blood cells

Viral meningitis CSF

Normal glucose normal white blood cells

Tuberculous meningitis CSF

Low glucose normal white blood cells

Bacterial meningitis urgency

Medical emergency requiring rapid antibiotics

Bacterial meningitis additional management

Isolation fluid monitoring seizure control

Bacterial meningitis steroid use

Used for brainstem herniation risk

Viral meningitis treatment

Symptomatic care usually resolves in one to two weeks

Herpes meningitis treatment

Acyclovir

Tuberculous meningitis treatment

Antitubercular drugs corticosteroids if severe

Bacterial meningitis mortality

Five to twenty five percent

Tuberculous meningitis mortality

Twenty to fifty percent

Aseptic meningitis prognosis

Self limiting with minimal deficits

Meningitis neurologic sequelae

Occurs in about thirty percent of bacterial or TB cases

Encephalitis definition

Inflammation of brain parenchyma

Encephalitis cause

Direct viral invasion or hypersensitivity reaction

Encephalitis primary location

Gray matter

Encephalitis common causes

Viruses bacteria fungi parasites

Encephalitis vectors

Ticks and mosquitoes

Herpes encephalitis significance

Most common cause of sporadic fatal encephalitis in US

Encephalitis pathology

Neuronal death edema hemorrhagic necrosis gliotic scars

Encephalitis early symptoms

Headache nausea vomiting fever

Encephalitis hallmark

Altered consciousness

Encephalitis progression

Agitation coma

Encephalitis focal deficits

Hemiparesis aphasia ataxia cognitive impairment

Encephalitis diagnosis

Lumbar puncture MRI PCR for herpes

Encephalitis imaging advantage

MRI detects early edema and vascular changes

Encephalitis EEG finding

Seizure activity

Encephalitis treatment

Acyclovir for herpes supportive care

Encephalitis severe management

Surgical decompression hyperventilation mannitol

Encephalitis recovery rate

Ten to fifty percent

Encephalitis poor prognosis

More severe in infants

Herpes encephalitis mortality

Twenty percent with high neurologic deficits