Seizure Disorders

Question 1

Focal Seizures

Answer 1

• Definition:
  
  • abnormal neuronal discharge from one discrete section of one hemisphere
• Classification – Level of Awareness:
  
  • Intact awareness (simple): consciousness fully maintained
  • -Impaired awareness (complex): consciousness impaired
• Classification – Onset:
  
  • -Motor: tonic-clonic, atonic, myoclonic
  • -Non-motor
  • -Unclassified: not enough info to determine onset (unwitnessed seizure)
• S/sxs:
  
  • Types are dependent on brain area
• PE:
  
  • Focal Seizures with retained awareness → no alteration in consciousness, but abnormal movements or sensations (used to be called simple partial seizure)
  • Focal Seizures with a loss of awareness → altered LOC, automatisms (i.e. lip smacking) (used to be called complex partial seizure)
    
    • → Present with a postictal state (confusion & memory loss) which helps to differentiate them from absence seizures
• Dx:
  
  • Initial workup to r/o reversible causes
  • Electrolytes: Na+, Ca2+, Mg
  • -Serum glucose
  • -Pregnancy test → can affect type of antiepileptic therapy the patient receives
  • -toxicology screen
  • -ECG
  • -EEG
  • -Neuroimaging: CT or MRI of the head → should be done all adults with their first seizure
• Tx:
  
  • May evolve into generalized tonic-clonic seizures
  • Tx: phenytoin, and carbamazepine = drugs of choice

Question 2

Types of Focal Seizures

Answer 2

• Focal Motor:
  
  • jerking movements of the face, one foot one arm, or another part
• Focal Sensory:
  
  • hearing problems, distorted olfactory sense, or hallucination
• Focal Autonomic:
  
  • changes in HR or rhythm, BP, bowel or bladder function
• Focal Psychic:
  
  • triggers emotion or memories causing fear, anxiety, or deja vu

Question 3

Generalized Seizures

Answer 3

aka Grand Mal Seizures

• Definition:
  
  • simultaneous neuronal discharge of both hemispheres (diffuse brain involvement)
  • Always have some level of impaired awareness
• Classification – Onset:
  
  • -Motor: tonic-clonic, atonic, myoclonic
  • -Non-motor: absence
  • **Tonic-clonic is most commonly seen in metabolic derangements, drug withdrawal, & head trauma
• S/sxs:
  
  • Tonic Clonic:
    
    • -Generalized body stiffness & rigidity
    • -Arched back
    • -Jerking movements of the trunk, extremities, & head
    • -Associated findings: tongue biting, incontinence, frothing at the mouth, eye blink, cyanosis
    • -Post-ictal phase
• Dx:
  
  • **Initial workup to r/o reversible causes
  • Seizures that develop during adolescence and adult life are usually caused by tumor, trauma, drug use, or alcohol withdrawal → in addition to blood work you should obtain a CT scan
• Tx:
  
  • Those at lower risk may not need medications until further evaluation is completed (or another seizure occurs)
  • -Tx the underlying cause
  • -Anti-seizure meds: phenytoin, fosphenytoin, levetiracetam, Valproic acid, phenobarbital; loading dose → daily dosing

Question 4

Absence Seizures

Answer 4

aka Petit Mal → type of generalized seizure

• Definition:
  
  • generalized seizure character by a brief (4-20 sec) loss of environmental awareness without loss of body tone (Type of Generalized seizure)
• Risks:
  
  • provoked by hyperventilation or flashing lights
• Age of Onset:
  
  • ~4-10 yo (Childhood)
• S/sxs:
  
  • -Sudden, marked impairment of consciousness without loss of body tone
  • -May be accompanied by simple automatisms: eyelid twitching, lip smacking
  • -”Staring into space”
  • -No post-ictal confusion & no memory of the event
• PE:
  
  • May have dozens of seizures per day which often go unrecognized
• Tx:
  
  • 1st line = ETHOSUXIMIDE
  • 2nd line = Valproic acid

Question 5

Status Epilepticus

Answer 5

• Definition:
  
  • 5+ minutes of continuous seizure activity OR recurrent seizure activity without return to baseline OR 2+ seizures within a 5 minute period.
• Etiologies:
  
  • metabolic, sepsis, CNS infx, stroke, TBI, drugs, cardiac arrest, encephalopathies, autoimmune encephalitis, breakthrough seizures, chronic EtOH abuse, CNS tumors, remote CNS pathologies
• S/sxs: Two types:
  
  • 1.Convulsive status epilepticus: presents with a regular pattern of contraction and extension of the arms and legs
  • 2. Non-Convulsive Status Epilepticus: includes complex partial status epilepticus and absence status epilepticus
• PE:
  
  • Untreated generalized seizures lasting >60 min may result in permanent brain damage; longer-lasting seizures may be fatal
• Dx:
  
  • Initial Assessment:
  • -ABCs
  • -Trauma Assessment
  • -Fingerstick Blood Glucose (FSGS)
• Tx:
  
  • Medical Emergency
  • Protect from injury: do not restrain patient & do not put anything in the mouth (but have suction available),
    
    • -Place patient in left lateral decubitus position (suppressed gag reflex ⇒ prone to aspiration of gastric contents)
  • -Immediate seizure control treatment: IV/IO Benzodiazepines (LORAZEPAM, midazolam, diazepam) initially after which you give phenytoin
  • -Closely monitor patient until recovery
  • -Post-Ictal: positioning, airway control, labs & imaging, longer-acting anti-seizure meds, EEG monitoring.

Question 6

Febrile Seizures

Answer 6

• Definition:
  
  • seizure resulting from an increase in body core temp (most common with temp >39C (102.2F))
• Pathophys:
  
  • high fevers increase neuronal excitability & lower seizure threshold
• Risks:
  
  • viral illness, genetics, certain immunizations (DTaP, MMR)
  • Most common between 6mo - 5 years
• S/sxs:
  
  • Simple Febrile Seizures:
    
    • -tonic-clonic seizure: most common type, lasts ~3-4 minutes & do not recur in 24 hour period
  • Complex Febrile Seizures:
    
    • -May be focal onset, prolonged, or recurrent within 24 hours
    • -20% of febrile seizures
    • -Todd Paresis: transient hemiparesis after a febrile seizure
• PE:
  
  • Hx questions: prior seizures? Family hx? Description, duration. Recent illness or abx use? Recent vax? Temperature
  • **Look for evidence of Can’t Miss Ddx: decreased LOC, petechial/purpuric( associated with sepsis due N. meningitidis) rash, meningismus, Kernig & Bruzinski, Fontanelle bulging, focal differences in muscle tone
• Dx:
  
  • dx of exclusion
  • -CBC, CMP low yield in simple febrile seizures
  • -UA, throat cx to identify source of infection
  • -No indication for imaging in simple febrile seizures & most complex febrile seizures
  • -CXR: if PNA suspected
  • -Lumbar puncture: to r/o meningitis/encephalitis based on clinical exam
• Tx:
  
  • -Protect from injury
  • -ABCs: have suction available
  • -IV Lorazepam or Diazepam
  • *Most are self-limited & end before patients arrive at the hospital
  • -Antipyretics, hydration, & cooling measures
  • -Tx the source of the fever
  • Observation

Question 7

Evaluation of 1st Seizure

Answer 7

• Key Hx Points:
  
  • description of aura, duration of seizure, nature of motor activity, loss of awareness, duration of postictal state, triggers, current meds, EtOH/drug use
• Labs:
  
  • rapid POC glucose, CBC/CMP/UA, toxicology, lactate, hCG, CT/MRI, ECG, EEG, LP (if infection suspected)
• All pts suffering a 1st seizure should be evaluated by a neurologist (EEG, MRI, risk-stratification, start anti-seizure drug)