week 3- neuro 2 Flashcards
• Seizure Disorder, terms, etio:
o Sz: abnormal, unregulated electrical discharge in brain’s cortical gray matter, transiently interrupts normal brain fxn → altered awareness, abn sensations, focal involuntary movements, convulsions (widespread violent involuntary contraction of voluntary muscles).
o Epilepsy: Common, mb serious neuro do; recurrent, unprovoked szs. st idiopathic, or various malformations, strokes, tumors can cause
o Nonepileptic szs: dt temporary do: Metabolic do, CNS infx, Drug toxicity or w/d
o Symptomatic sz: dt known cause (brain tumor or stroke)
o Psychogenic sz (aka Pseudoseizure): No electrical discharge in brain
o Etio: AI dos, Cerebral edema, Head trauma, CNS infx, Congenital or Developmental abn, Drugs or toxins, Expanding intracranial lesions, Hyperpyrexia (↑ fever), Metabolic disturbances, Pressure related, W/d syndromes
• Generalized Seizures, types:
o Electrical discharge in entire cortex of both hemispheres; Complete LOC; usu dt metabolic disturbances o Infantile spasms o Absence seizures (aka Petit Mal) o Tonic-clonic seizures (aka Grand Mal) o Atonic seizures o Myoclonic seizures
• Infantile spasms
o Sudden flexion and adduction of arms with forward flexion of trunk
o few seconds, many x/d
o only in 1st 5 yrs, usu replaced by other seizure types
• Absence seizures (aka Petit Mal):
o Typical: ages 4-12; FHx in 40%; mb many x/d, 5-30 sec. st LOC, eyelid fluttering; stares vacantly, abruptly stop/resume activity; No falling or convulsing; usu sitting, mb preceded by hyperventilation. Rare with exercise. Usu normal Neuro and cognitive exams
o Atypical: usu part of Lennox-Gastaut syndrome (severe begins under 4) Last longer. Complete LOC. usu hx of damage to nervous system, szs continue into adulthood
• Tonic-clonic seizures (aka Grand Mal)
o Primary: Begin wi outcry → LOC and falling→ tonic contraction →clonic motion of muscles of head, extremities, trunk. St: Urinary or fecal incontinence, Tongue biting, Frothing at mouth, Usu 1-2 min, No aura
o Secondary: Begin w simple partial or complex partial seizure that generalizes; May have all the sxs as above except usu. no outcry
• Atonic, myoclonic seizures
o A: usu children (Lennox-Gastaut); Brief complete loss of muscle tone, LOC; Often fall to ground: risk head injury or trauma
o M: Brief, lightening-like jerks of a limb, several limbs or trunk; mb repetitive; UL or BL. Unlike other BL szs, no LOC unless progresses into general tonic-clonic sz
• Partial Seizures (as opposed to generalized), types:
o Excess neuronal discharge in one cerebral cortex; Often from structural abnormalities
o Simple
o Complex
• Simple Partial, types:
o Cause motor, sensory, or psychomotor sxs without LOC
o Types: MOTOR AND SENSORY SEIZURES INDICATE STRUCTURAL BRAIN DISEASE, THE FOCAL ONSET LOCALIZING THE LESION: FULL INVESTIGATION IS MANDATORY!!!!
o Motor: Arise in frontal motor cortex, movts in contralateral face, trunk or limbs; clonic (shaking), usu begins in hand or face (largest representative cortical area); Jacksonian motor seizure (aka Jacksonian March): A “march” of involuntary muscle movt from one muscle group to next
o Sensory: Arise in sensory cortex; Parasthesias or tingling in extremity or face st assoc w distortion of body image; Visual, Auditory and Autonomic all RARE
• Complex Partial
o reduced but not complete LOC; Usu in temporal lobe, w aura; stare; Consciousness impaired, some awareness of environment (may withdraw from noxious stimuli)
o Automatisms: Oral: involuntary chewing or lip smacking; Limbs: often purposeless movs of hands; if ambulatory, may wander off
o Head or eye deviation to contralateral side
o Motor sxs 1-2 min. Confusion 1-2hr
• Ssx of seizures
o mb preceded by aura
o usu end in 1-2 min
o Generalized seizures followed by postictal state: Deep sleep, HA, Confusion, Muscle soreness
o Sometimes Todd’s paralysis after partial motor seizure (transient neuro deficit, usu weakness of CL limb)
• Hx for seizures
o sxs (aura?), duration?
o Ask family members or witnesses
o Risk factors: head trauma or CNS infx, Known neuro do; Drug use or w/d (esp recreational); Alcohol w/d; Non-adherence to anticonvulsants; FHx seizures or neuro dos
o Rare triggers: Repetitive sounds, Flashing lights, Video games, Touching certain body part, Sleep deprivation
• PE, work-up, px for seizures:
o PE: mb bitten tongue, soiled clothing (incontinence), prolonged confusion; Fever and stiff neck?- Meningitis or encephalitis; Papilledema?- ↑intracranial pressure
o Labs: CBC, CMP (w glucose), LFTs, Tox screen, Lumbar puncture (if infx suspected but usu. CT brain first)
o Imaging: CT to exclude mass or hemorrhage; Follow-up MRI Recommended when CT is (-); EEG Critical for Dx but normal EEG cannot necessarily r/o seizure do
o Px: With tx: szs eliminated in 1/3 of pts; 1/3 frequency ↓ > 50%; 60% well-controlled by meds can eventually stop meds, remain sz free
• Brain Abscess, etio, ssx, dx::
o intracerebral collection of pus
o Etio: cranial infx (osteomyelitis, mastoiditis, sinusitis, subdural empyema); head wound; Hematogenous
o Ssx: HA, N/V, lethargy, fever, Focal neuro deficits, szs
o Dx: CT or MRI
• Encephalitis:
o inflam parenchyma of brain
o Etio: direct viral invasion; In US: Mosquito-borne arboviral encephalitides: infect when weather is warm (spring, summer, fall); mc sporadic: HSV; HIV
o At risk: Children, Elderly, weak immune systems
o Ssx: Fever, HA, Altered mental status, szs, Focal neuro deficits
o Dx: MRI, CSF testing (w HSV will show ↑ WBCs, esp lymphocytes; Suspect w unexplained alterations in mental status
o Px: Recovery mb very long; Permanent neuro deficits common if survive severe infx
• Rabies:
o viral encephalitis transmitted by saliva of infected bats and other select mammals
o ssx: Depression, Fever, Agitation, Excessive salivation, Hydrophobia
o dx: Suspect w encephalitis or ascending paralysis, recent hx animal bite or exposure to bats; Skin bx; St PCR of fluid or tissue samples
• Helminthic Brain Infections:
o parasitic worms infx CNS
o millions of ppl in developing countries, mb travelers or recent immigrants
o In Western Hemisphere: mc pork tapeworm (taenia solium)
o Ssx: encephalitis, meningitis, cerebral masses, hydrocephalus, myelopathy
• Progressive Multifocal Leukoencephalopathy
o Etio: reactivation of JC virus usu pts. w impaired cell-mediated immunity (HIV)
o Path: demyelinating dz; esp affects parietal and temporal lobes
o Ssx: Clumsiness mb 1st sx, Hemiparesis mc; Aphasia, dysarthria, hemianopia
o Dx: MRI (Multifocal, non-enhancing lesions w/o mass effcct), CSF: look for JC virus DNA w PCR; Brain bx st for definitive Dx
• Subdural Empyema:
o collection of pus bw dura mater and arachnoid
o Etio: Usu complication of sinusitis, Ear infx, Cranial trauma, Rarely bacteremia
o Ssx: Fever, Lethargy, Focal neuro deficit, sz
o Dx: MRI
• Prion dz (Transmissible Spongioform Encephalopathies):
o Progressive, fatal, untreatable brain dos
o rare; worldwide: 1 in 1,000,0000
o Transmission: hereditary, sporadic, transmitted (person to person w kuru, or animal to person w CJD)
o Path: misfolding of normal cell- surface brain protein (prion protein, PrP), exact function is unknown
• Creutzfeldt-Jakob Disease (CJD):
o sporadic, familial or acquired: Sporadic (sCJD) 85%; Variant (vCJD) dt eating meat from cattle with bovine spongioform encephalopathy (BSE; aka Mad Cow Dz); usu > 40yr (avg 60)
o Ssx: Memory loss, Confusion; Incoordination, ataxia; Startle myoclonus (provoked by noise, etc)
o Dx: Suspect in elderly w rapidly progressing dementia esp w ataxia or myoclonus; MRI
o Px: Death usu in 6-12 mos; life expectancy for vCJD is longer (avg 1.5 yrs)
• Other types of prion dzs:
o Variably Protease Sensitive Prionopathy (VPSPr)
o Gerstmann-Sträussler-Scheinker Disease: Similar to CJD, much less common; familial (AD); earlier age than CJD, longer life span
o Fatal Insomnia: Rare hereditary or sporadic; onset usu 40; difficulty sleeping, motor dysfunction, death
o Kuru: in Papua New Guinea, spread from man to man thru cannibalism
• Meningitis:
o Inflam meninges and subarachnoid space; dt infx, other do or rxn to drugs
o Ssx: HA, fever, nuchal rigidity (seen in all types)
o PE: (+) Kernig, (+)Brudzinski; difficulty touching chin to chest with mouth closed; difficulty touching forehead or chin to knee
o Dx: CSF; MRI 1st if ssx of ↑ intracranial P, to avoid brain herniation in addition to blood cultures
• Acute Bacterial Meningitis
o rapidly progressing bacterial infx of meninges and subarachnoid space
o Path: Hematogenous spread; Nearby infx structures: sinuses, middle ear; Congenital or acquired defect in skull (penetrating head wound, surgery, etc.)
o Mc etio: Children (Neisseria meningitidis, Streptococcus pneumoniae), Middle age and elderly (Strep Pneumoniae)
o Ssx: 3-5 d progressive non-specific sxs: malaise, fever, irritability, vomiting, tachycardia, HA, photophobia, changes in mental status (lethargy, obtundation), nuchal rigidity (not all pts), st back pain, szs in 40% children
o Dx: CSF (↑WBCs (usu. PMNs), protein, ↓ glucose), CBC with diff, CMP, Blood culture
o Mortality: 60
• Viral Meningitis:
o Less severe than bacterial
o Mc dt Enteroviruses; also HSV
o Ssx: 1st Fever, Myalgia, GI or Resp sxs; then HA, fever, nuchal rigidity
o Dx: CSF: Protein slightly ↑ but less than in bacterial; Glucose usu normal or ↓ slightly; ↑ WBCs (lymphocytes)
