Neurology Flashcards
At least 1 unprovoked epileptic seizure with either a second one or EEG convincingly demonstrating enduring predisposition to develop recurrences
2 or more unprovoked seizures occuring in a time frame longer than 24 hours
Epilepsy
6 months to 6 years
Normal neurologic exam
Occurs with fever (not due to CNS infection or metabolic imbalance)
Most commonly due to viral URTI, OM, Roseola, UTI
Normal EEG
Febrile seizure
Few seconds to 15 minutes
Generalized
Only once in 24 hours
Simple febrile seizure
Focal
More than 15 minutes
Recurrent more than 2 in 24 hours
or
3 seizures in 3 days
Complex febrile seizure
Major risk factor for seizure recurrence
Age <1 year (most important)
Duration of fever <24 h
Fever 38-39 before onset, low
Management of febrile seizures
In actively convulsing: Do not put anything in mouth (except when biting the tongue) Time the event Do not restrain Do not give anything to drink Turn to the side to prevent choking Put something under head O2 not needed
LP in <18 months not fully immunized to r/o meningitis
Seizure >5 minutes or recurrent seizure tx
Diazepam 0.2-0.4 rectal, IV
Antiepileptic drugs that prevent recurrence of febrile seizure
Phenobarbital - dec cognitive function
Valproate - hepatotoxicity
Antibodies target NR1 subunit of NMDA
Encephalitis due to antibodies against neuronal cell surface proteins and synaptic receptors in synaptic transmission
Anti-N-Methyl-D-Aspartate Receptor Encephalitis
NMDAR Encephalitis
Glutamate receptor and ion channel
Activated when glutamine and glycine bind to it
Important for controlling synaptic plasticity and memory
NMDAR
Glutamate exerts toxic acitivity through 3 receptor subtypes
NMDAR
AMPA (amino-3-hydroxy-5-methyl-4-isoxazol-proprionic acid)
KA (kainic acid)
NMDAR Tx
Methylprednisone IV 5 days
IVIG
More common etiology of CNS infection
viral
Most common acute viral encephalitis in the Philippines
Japanese encephalitis
Most common acute viral encephalitis in the worle
Enterovirus
Chronic meningitis
Subacute Sclerosing Panencephalitis
Hypothermia Fever (ominous or severe) Seizure (late) Lethargy or irritability Poor feeding Respiratory distess Diarrhea
Are all symptoms of CNS infection in
Neonates (0-28 days)
Fever (50%) Seizure (40%) Poor feeding Abdominal distention Bulging anterior fontanel Altered sensorium
Are all symptoms of CNS infection in
Infants (1 mo-2 years)
Fever
Headache
Nuchal rigidity
Are all symptoms of CNS infection in
Older children and adult
The most common cause of bacterial meningitis in 0-2 months old
Philippines
West
E coli (Gram negative) Pseudomonas Klebsiella Listeria Salmonella
Group B streptococcus pneumoniae
The most common cause of bacterial meningitis in 3 months to 6 years
H influenzae
Streptococcus pneumoniae
Can be prevented through vaccines given as early as 6 weeks
The most common cause of early to late childhood bacterial meningitis
Streptococcus pneumoniae Neisseria meningitidis (Meningococcus)
Meningitis mode of transmission
Respiratory droplet
Bacterial meningitis pathophysiology
Nasopharyngeal colonization
Local invasion
Bacteremia
Bacterial replication
Subarachnoid space inflammation (seizures and fever)
TNF and inflammatory enzymes (reaction to infection)
Increased BBB permeability and ICP
3 types of edema: vasogenic, cytotoxic and interstitial
Causes neurologic problems seizure and fever
Subarachnoid Space inflammation
Frequent sequelae of bacterial meningitis
Cerebral infarction from vascular occlusion bec of inflammation, vasospasm and thrombosis
Common acute complication of bacterial meningitis
Inc ICP (tentorial herniation -> temporal lobe and CN III palsy)
Communicating hydrocephalus by adhesive thickening of arachnoid around basal cistern
Non obstructive from fibrosis is chronic
Inc CSF protein From inc vascular permeability of BBB and loss of albumin-rich fluid
Hypoglycorrachia (dec CSF glucose) dec glucose transport by cerebral tissue
Pathogenesis of bacterial meningitis most commonly results from
Hematogenous dissemination from a distant site (nasopharyngeal colonization)
N meningitides and Hib attach to mucosal epithelium via Vili and breaches mucosa to enter circulation
2 patterns of acute meningitis
Fever with URTI/GIT -> Meningitis -> Non-specific signs of CNS (lethargy and irritability)
Less common but more dramatic: sudden onset rapid manifestation of shock, purpura, DIC and reduced levels of consciousness progressing to coma and death within 24 h
+ Kernig and Brudzinski
Seizure
Seizure occuring within first 4 days
Seizure persisting after 4th day
No significance
Poor prognosis
Elicited by stroking the skin with blunt object and observing raised red streak within 30-60 seconds
Tache cerebrale
Photophobia
LP is done at this level of the child
22 gauge at L3-L4
23 gauge at L4-L5 (newborn)
LP contraindications
Cardiorespiratory compromise or shock -dyspnea, tachycardia, coma or respirator
Increased ICP or impending herniation
Bulging fontanel, CN 3/6 palsy with depressed level of consciousness, hypertension and bradycardia with respiratory abnormalities
Space occupying lesions - focal neurologic signs
Obstructive hydrocephalus
Local infection, epidural abscess
Bleeding dyscrasias
Thrombocytopenia (PC <20)
Imaging to rule out CI
Infection of skin overlying LP site
Normal/high opening pressure WBC: 1,000 - 10,000 (PMN >80) Slight increase in RBC VERY HIGH PROTEIN (100-500) Glucose <40? Gram stain 60-90% Positive Culture % positive: 70-85
Bacterial Meningitis
Normal opening pressure WBC: <300 (PMN <20) BECAUSE MONONUCLEAR LYMPHOCYTES RBC count Normal Protein Normal Glucose Normal Gram stain Negative Culture % positive: 25
Viral
Normal/high opening pressure WBC: 20-500 (PMN <50) Normal RBC High protein Glucose <40 Gram stain Negative Culture % positive: 25-50
Fungal
Opening pressure usually high WBC 50-500 (PMN <20) RBC Count Normal Protein High Glucose <40 Gram stain 40-80% positive Culture % positive: 50-80
Tuberculous meningitis
Basal enhancement on CT Scan
TB Meningitis
Subdural effusion on CT Scan
H influenzae
S pneumoniae
N meningitides (Meninggococcal)
Edema of brain is seen only in infancy from 6
mo to 2 years which resolves spontaneously until it gets infected becoming empyema.
Subdural empyema is a complication of this population
Childhood
not seen in adults
Low sugar content
Higher protein content than CSF
Uncommon complication of bacterial meningitis usually from H influenzae
Brain abscess
Contiguous focus of infection (otitis media, mastoiditis)
Hematogenous spread from distant focus
Cranial trauma
Complication of N meningitides meninggococci
Pericarditis
Arthritis
most severe, Long term sequelae of Meningitis in infancy
Sensorineural hearing loss (15-20%) bec of cochlear nerve affectation
Tx: Cochlear nerve implant
Highest mortality of bacterial meningitis
Pneumococcal meningitis
Poorest prognosis in infants <6 mo
Bacterial meningitis Tx in 0-2 months
Cefotaxime (3rd gen) + Aminoglycoside
Gram Neg
Group B Strep
Bacterial meningitis in >2 months - 5 years
Ceftriaxone
Cefotaxime + Vancomycin
H influenzae
Strep pneumoniae
Meningitidis
Bacterial meningitis in >5-18
Ceftriazone
Pen G
For Hib causing meningitis, also give
IV Dexamethasone 2 days
N meningitidis chemoprophylaxis is given
all close contacts of patients with meningococcal meningitis regardless of age or immunization
(direct exposure to oral secretions mouth to mouth, suctioning, intubation)
N meningitidis chemoprophylaxis
Rifampicin 10 mg/kg/dose every 12h for 2 DAYS
Routine administration of Meningococcal vaccine is recommended for
11-12 years old adolescents
High risk children >2 years with anatomic or functional asplenia or deficiency of terminal complement proteins
College freshmen
Adjunct with chemoprophylaxis for exposed contacts and epidemic
Meningitis vaccine
Quadrivalent (A, C, Y, W-135 Conjugated vaccine MCV 4; Menactra)
H influenzae Rifampicin 20 mg/kg/h OD for 4 DAYS prophylaxis
is given in
All household contacts of patients (spent minimum 4 hours, at least 5/7 days preceding hosp)
Close family member younger than 3-4 years without immunization
Immunocompromised
Strep pneumoniae meningitis prophylaxis is through
Routine administration of Pneumococcal conjugate vaccine PCV 13
for children younger than 2 (2, 4, 6 months)
Functional or anatomical asplenia
Immunodeficiency
Most common form of CNS infection in Philippines
TB Meningitis
Inflammation of leptomeninges
Tuberculoma
Basal exudates
Hydrocephalus due to thick exudates (Communicating hydrocephalus)
CN palsies due to basal location
Vasculitis
TB Meningitis
Period of highest risk of development of TB infection
1-3 months post primary TB infection
Metastatic TB foci lodge in
Meninges
Cerebral or spinal tissue
Choroid plexus
Arises from primary hematogenous seeding or secondary spread from extracranial focus
Rupture of these foci cause spread into subarachnoid space
Rich focus: Subependymal or tuberculid
Neuropathologic findings in TB Meningitis
Basal exudates
Encephalitis Border Zone
Radiologic triad of TB Meningitis
Basal meningitis
Cerebral infarction/arteritis
Hydrocephalus
CSF analysis of TB Meningitis shows
Pellicle formation
Cobweb like clot
TB Meningitis earliest age of onset
4 months
bec of 2-3 months incubation period from primary infection
Flat sulci
Hydrocephalus
on UTZ
TB Meningitis Tx
2 months HRZE (anti-Koch’s)
10 months HR (double therapy)
Streptomycin side effect
Irreversible deafness
Ethambutol side effect
Optic neurotis
Color blindness
Steroids Dexamethasone and Oral Prednisone given for stage
2 and 3 for 1-2 months
Tx on Multidrug resistant TB
Fluoroquinolone
Most common fungal infection causing meningitis more common in immunocompromised
Cryptococcus neoformans
Exposure for cryptococcus neoformans
Pigeons
Cryptococcus neoformans is essily diagnosed by
Fungal on India ink smear and CALAS
Cryptococcus neoformans Tx
Amphotericin B 4-6 weeks
Opacity of basal leptomeninges
Cryptococcal meningitis
Collection of pus surrounded by well vascularized capsule usually from gram negative meningitis:
Citrobacter diversus (neonates)?
Proteus
Serratia
Polymicrobial
Brain abscess
Brain abscess predisposing factors
Embolus from CHD Right to left shunt (TOF)
Penetrating injury
Hematogenous spread
ENT infection
Large multiloculated abscess with hyperdense ring enhancement on CT Scan
Brain abscess
CI in brain abscess
Lumbar tap may cause herniation
Diagnostic test of choice in brain abscess
MRI
on CT hypodense center
Brain abscess Tx
Ceftriaxone + Metronidazole
Cefotaxime + Metronidazole
If unknown
Cefotaxime/Ceftriaxone + Metronidazole + Vancomycin
Known CHD
Ampi-Sul or Ceftriaxone/Cefotaxime + Metronidazole
4-6 weeks IV
Surgical indication brain abscess
> 2.5 in diameter Gas present in abscess Multiloculated lesion Abscess in posterior fossa Fungus
Most common cause of encephalitis in the Philippines
Japanese encephalitis
Immunization required
HSV encephalitis affects this part of the brain
Temporal lobe
Subfrontal regions
Hippocampus
Arbovirus (Japanese) encephalitis affects this part of brain
Entire brain
Rabies affects this part of the brain
Basal structures
HSV Encephalitis EEG
Paroxysmal lateralized epileptiform discharges
PLEDS (frontal or temporal)
EEG in meningitis will always be normal
Most common vaccine-preventable cause of encephalitis in Asia and Pacific region
Japanese Encephalitis
Yellow virus
Arbovirus transmitted by
Culex
Single stranded RNA Flavivirus with enveloped glycoproteins
Mostly seen in rice fields, temperate and tropical areas
Jap encephalitis
Japanese encephalitis incubation period
6-16 days
Jap encephalitis enters blood stream -> peripheral tissue -> cortex especially the
Basal Ganglia
Within 3 days from fever
Altered sensorium
Convulsion
Neck stiffness, muscular rigidity
Mask-like facies, involuntary movement
Splitting, shouting, cursing, mild personality change but NO VIOLENT BEHAVIOR
Abulia (inability to act decisively), wide unblinking eyes, bizarre posturing, papilledema, dysphagia, asymetric irregular distribution of motor and tone abnormalities
Japanese encephalitis
Gold standard for Diagnosis of Japanese Encephalitis
IgM and IgG capture ELISA
Repeated if initially negative
High intensity/hyperintense T2 weighted imaging of Thalamus, cerebral hemispheres, and cerebellum on MRI
Diffuse theta and delta waves on EEG
Japanese Encephalitis
Live attenuated recombinant
0.5 ml single injection for >1 year
Booster for 18 years and above but not needed until 5 years after primary administration
JEV vaccine
Long term consequence of neurologic impairment in JEV
Limb contracture
Bed sore
Psychiatric symptoms Emotional and behavioral disturbances Seizures Autonomic instability Automatisms Extrapyramidal signs Speech dysfunction
Ovarian teratomas in <18
Anti-NMDAR Encephalitis
Do UTZ
NMDAR Confirmatory diagnostic study
Detection of antibodies to NR1 subunits of NMDAR
