Types of brain injuries
Local: contusion, laceration, hematoma, herniation
Diffuse: axonal shearing, small hemorrhages
Secondary: edema, hypoxia, hypotension, infections, salt/water imbalance, concussion, post-traumatic epilepsy (months->years post injury)
Brain abscesses
- organisms reach brain
- secondary to inflammatory process elsehwere
- involves white matter, often reaches fronal and parietal lobes through sagittal sinus
- generalized infection and increased ICP-> specific neurological s/s
s/s: HA, convulsions, hemiparesis, incoordination
Leptomeningitis
Infection spread through the CSF c inflammatory process of pia mater, arachnoid mater, and superficial CNA tissues, to include SAS
organisms cross blood-brain barries and blood-CSF barries
CSF has few antibodies, therfore ideal growth medium
classified as bacterial or viral (aseptic)
Bacterial Meningitits cause by age
neonate: e. coli
childhood: H influenzae
adolescent: N meningitides
adult: S pneumoniae
Bacterial Meningitis
inflamed congested pia-arachnoid mater with PMN exudate->obstructs ventricular foramina= increased ICP
untreated leads to death
Brudzinski neck sign: neck flexion causes hip/knee flexion
decreased blood sugar
s/s: HA, vomiting, fever, altered consciousness, convulsions, nuchal rigidity, irritability
Viral meningitis
s/s similar to bacterial, but not life threatening
fulminating
children and young adults
blood sugar levels normal
Chronic meningitis
TB or syphilis
gelatinous exudate in meninges, increased lymphocytes, etc
If in SAS, may lead to hydrocephalus
s/s: HA, vomiting, mental confusion, wt loss, fatigue, night sweats, chest p!, general malaise
med management: antimicrobial antibiotics for bacteria, treat viral infections symptomatically
Hydrocephalus s/s
gait disturbance, incontinence, altered mental status
Encephalitis
viral invasion of brain and SC
edema and inflammation of the brain/sc destroying white matter
increased ICP lead to transtentorial herniation
increased in immunosuppressed
viral latency of months to years
s/s:HA, fever, nuchal rigidity, vomiting, malaise->coma, CN palsies, hemiplegia
encephalitis terms
encepalitis: inflammation of brain
encephalomeningitis: inflammation of the brain and spinal cord
Encephalomyeloneuropathy: inflammation of the brain, spinal cord, and PNS
Acute encephalitis
viral: affects frontal/temporal lobe gray
most fatal: some survive with severe dementia
herpes
parainfectious encephalitis: MMR, VZI
toxic: west nile and lyme
“slow virus” encephalitits
long latent incubation: fatal within months: progressive dementia
spongiform: bubbles and holes in brain cortex
s/s: personality abnormalities, visual spatial orientation/coordination problems: lead to severe dementia with myclonus
Creutzfeldt-Jacob Disease
familial, sporadic, or iatrogenic
can take decades to show s/s often misdiagnosed (alzheimer's)
rapid dementia and myoclonus
s/s: ambiguous at first: depression, confusion, personality/behavior change, strange sensations, coordination and visual issues. language, sight, weakness, and coordination worsen.
14-3-3 protein spinal fluid test: 95% effective in diagnosis
death in 6 mo-1 year.
Brain tumors
pathologically benign may be clinically malignant
may spread via CSF to produce carcinomatous meningitis
brain tumor etiology
40900 US cases per year
16500 malignant c 13000 deaths
0-15 years old and 50-70
causes: heredity, chemical, electromagnetic field exposure, radiation
Brain tumor manifestations
ICP: HA, N&V, papilledema Cerebellar s/s Bitemporal hemianopia: both temporal fields gone Abnormal reflexes Seizures Sensory disturbance
Distribution of primary brain tumors
glioblastoms: 50%
meningioma: 17
astrocytoma: 10%
pituitary: 4%
other: 19%
