CNS infections Flashcards
Which type of meningitis is associated with worse outcomes?
Bacterial
What are the three most common types of bacterial meningitis?
Haemophilus - most common, children <2 at greatest risk
meningococcal - children 2-18, increased risk associated with crowding (dorms)
pneumococcal - greater cognitive impairment
What are ways of bacteria spread to the meninges?
From an adjacent infected area (ears, sinuses)
From the environment (penetrating injury, congenital defect)
Through the bloodstream (hematogenous) - MOST COMMON
What is the primary cause of brain damage in bacterial meningitis?
Inflammation, which leads to tissue and vascular injury, septic thrombosis, and smaller infarcts
Which cranial nerve is most often impacted in meningitis?
VIII -auditory - can result in sensorineural hearing loss
CN defects are more common in children than adults
What is mortality rate of BM?
10%, down from near 90% since the development of antibiotics in the 50s
What are the most common neurobehavioral sequelae of BM?
Hearing loss (11%)
ID (4%)
Spasticity/paresis (4%)
Seizure disorders (4%)
Cognitive/behavioral issues are most common in children (78%)
What are the two most vulnerable age groups for BM?
Children < 5 y.o. and older adults (60+)
What is the biggest medical risk factor for BM?
Immunosuppression
Causes include treatment
HIV
Cystic fibrosis
Diabetes
What are risk factors for worse outcomes in children with BM?
Acute neurological complications (prolonged seizures, coma, bilateral hearing loss)
Low CSF glucose levels
<1 y.o. - worse language outcomes
Male gender - worse behavioral outcomes
What are symptoms of acute BM?
Sudden fever
Severe headaches
Nuchal rigidity (stiff neck)
What are symptoms of gradual BM?
Typically non-specific “flu-like” symptoms
What are common presenting symptoms of BM in children?
Hyperthermia, lethargy, anorexia/vomiting, respiratory distress, irritability, jaundice, bulging fontanelle (space between bones of skull where sutures are not fully formed in an infant), diarrhea, nuchal rigidity
What is the diagnostic method to confirm BM?
Lumbar puncture - look for bacteria, also red & white blood cells, high protein levels, and low glucose
Are CT and brain MRI useful in diagnosis of BM?
No - meningeal enhancement may be seen but absence dis not a rule out
What are academic consequences in children with BM?
More than twice as likely to require special education
More likely to repeat a grade
What are NP findings in adults with meningitis?
Attention problems, slowed processing speed, executive deficits
Sensorimotor problems - hearing loss, hemiparesis, cortical blindness, ataxia* (* - typically resolve)
Memory findings are mixed
What are NP findings in children with meningitis?
Lower IQ in those with acute complications
Attention problems (elevated ADHD symptoms)
Language problems in those with BM before 1 y.o.
Executive deficits below expectation but not impaired
Behavioral changes
What is aseptic meningitis?
Meningitis caused by viruses, fungi, and parasites
! Stuckey mentioned tuberculosis but it is caused by bacteria
What is the most common cause of aseptic meningitis?
Enteroviruses
Which type of meningitis if more common?
Viral
What are symptoms of VM?
Severe headache, fever, nausea, vomiting, still neck, rash, fatigue
Flu-like symptoms precede neurologic symptoms by about 48 hours
What diagnostic methods are used in VM?
LP and blood work to detect viral pathogens
Is there a specific treatment for VM?
No, treatment is supportive (rest, fluids, anti-inflammatory)
What are NP findings in viral M?
Mild to moderate attention and processing speed issues
No long-term problems
What is the most common cause of encephalitis?
Viruses:
primary - direct infection of the brain
secondary - from a previous viral infection (e.g., chickenpox) or immunization (measles vaccination)
What are common viruses causing encephalitis?
Herpes simplex (HSV) Varicall zoster Epstein-Barr adenoviruses enteroviruses arboviruses (Anthropod Borne) cytomegalovirus
What is the pathway of HSV to the CNS?
Along the trigeminal nerve
What viruses are associated with the highest mortality in encephalitis?
Rabies and HSV (if not treated)
What age groups are associated with the highest prevalence rates of encephalitis?
Children and young adults
What virus/encephalitis is associated with more cognitive and psychiatric impairments?
HSV encephalitis (2-4x risk for cog impairment) Worse outcome in bilateral lesions
What are stages and symptoms of encephalitis?
Acute (hours to days) - severe HA, fever, altered mental status, general and focal neurologic signs
Subacute (weeks) - seizures and speech disturbance
Chronic - can progress over years with occasional acute symptoms (HIV, Lyme disease)
What is the behavioral presentation of HSV encephalitis?
Psychotic and affective symptoms
What encephalitis may require a hemispherectomy?
Rasmussen’s
What is a common cognitive sequalae of HSV encephalitis?
Anterograde amnesia
What are consequences of intracranial abcess in the brain?
Increased intracranial pressure
Mass effects
Which type of abcess is more common in the spinal cord?
Epidural abscess
What is a sign of brain abcess on the CT or MRI with contrast?
Ring enhancing lesions
What are symptoms of prion disease?
Rapidly progressive dementia Personality changes Hallucinations Speech impairment Physical symptoms - ataxia, weakness
What viral disease results in progressive and multifocal damage of the white matter?
Progressive multifocal neuroencephalopathy
typically affects immune compromised indivdiuals
What is the most common cause of brain abcess in patient with HIV/AIDS?
Cerebral toxoplasmosis
Which viral disease resembles multiple sclerosis?
Acute disseminated encephalomyelitis (ADEM)
What are MRI findings associated with acute disseminated encephalomyelitis?
White matter intensities in both hemispheres, cerebellum, and the spinal cord
What is associated with better outcomes: ADEM or pediatric MS?
ADEM
What are paraneoplastic disorders?
Neurologic disorders associated with cancer and caused by autoimmune reaction in response to the tumor
What is leptomeningitis?
Inflammation of only the pia mater and subarachnoid space
What is transverse myelitis?
Caused by an inflammatory process in the spinal cord, results in demyelination of axons
