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• 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 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)


• Noninfectious Meningitis

o less severe than acute bacterial
o dt Noninfectious Dos: Metastatic CA, Sarcoidosis, Behçet syndrome, SLE, Sjögren RA, Rupture of intracranial cysticercal or epidermoid cyst, Drugs, Vaccines
o ssx: typical
o dx: sterile CSF (no sign infx)


• Recurrent Meningitis

o dt bacteria, virus, or noninfectious; mc HSV
o HSV:  3 episodes fever, nuchal rigidity, and CSF with ↑ lymph; episodes last 2-5 d, resolve spontaneously
o bacteril: suspect congenital or acquired defect of spine or skull that has not been corrected
o Drugs: causative agent is used again accidently or intentionally


• Subacute and Chronic Meningitis

o Subacute: Develops over d-wks
o Chronic: last > 4wks
o Possible Causes: Fungi, Mycobacterium tuberculosis, Rickettsiae, Spirochetes, Toxoplasma gondii, HIV, Enteroviruses, AI or rheumatic dos (eg, SLE, RA), CA
o Dx: Clinical findings non-specific; mb not dx w CSF, mb need more invasive testing; Cisternal or ventricular puncture, bx


• Tremor:

o Involuntary, rhythmic movement of any body part dt contraction of agonist/antagonist muscle groups
o Most prevalent movt do
o Pathogenesis: unclear
o Physiologic (normal): Evident on maintaining a fixed posture, Fast in rate; Enhanced by fatigue, anxiety, drugs; Non-disabling
o Pathologic: at rest or w movt, Slow in rate, Coarse in character, Socially and physically disabling; Resting: occur when body part is fully supported against gravity; Action: occur during motion


• Essential Tremor

o Not benign or essential; FHx in 50%
o 20x MC than PD
o Ssx: w voluntary movt (action tremor; Parkinsonian is at rest)
o Usu BL
o Can worsen with age and interfere with normal activity
o Alcohol alleviates sxs, reduces overactivity of cerebellum (alcoholism may result)


• Hx for tremor:

o Onset? Agg. factors? Body parts affected?
o ROS: Recent weight loss, ↓ appetite, diarrhea, palpitations, heat intolerance (hyperthyroid); Muscle rigidity, gait and postural problems, slow movt (Parkinsonism); Sudden onset of motor weakness, dysarthria (stroke), etc
o FHx: Essential tremor? Other neuro dz?
o SHx: Meds and drugs