Seizures and epilepsy (mechanism of disease)

This is a flowchart on seizures and epilepsy, covering the etiology, pathophysiology, and manifestations.

ADDITIONAL TAGS:
Atonic seizure ("drop attack"):
Nonmotor (absence) seizure:
Autoimmune encephalitides (anti-NMDA receptor encephalitis)
Brain cancer/mets → cranial radiation therapy
Brain tumors and metastases
Tuberous sclerosis; hippocampal sclerosis
Perinatal injury (hypoxic-ischemic injury)
Congenital cerebral or arteriovenous malformations
Hormones (menstrual cycle; post menopause)
Flashing lights (strobe lights, video games)
Medication side effects
Autoimmune flares (SLE)
Metabolic disturbances (uremia)
Risk factors / SDOH
Cell / tissue damage
Structural factors
Seizures and epilepsy
Medicine / drugs
Infectious / microbial
Biochem / electrolytes
Immunology / inflammation
Signs / symptoms
Tests / imaging / labs
Neurological pathology
Genetic / hereditary
Flow physiology
Pathophysiology
Etiology
Manifestations
Amnesia of the event
Seizure: excessive and/or hypersynchronous episode of transient electrical brain activity
Epilepsy: chronic neurologic disorder characterized by a predisposition to seizures
Traumatic brain injury
Stroke, cerebral vascular accident
Intracranial surgery
Meningitis, encephalitis
Hypocalcemia, hypoglycemia
Alcohol withdrawal
Recreational drugs
Excessive physical exertion
Alcohol consumption
Fever (especially in children)
Sleep deprivation
Music → emotional response
Medication issues (adherence; changes)
Seizure triggers (with and without epilepsy):
Microcephaly, megalocephaly, cortical dysgenesis
Chromosomal abnormalities (Angelman, Prader-Willi, Rett syndromes)
Metabolic d/o (PKU, glycosylation d/o, lysosomal storage dz, peroxisomal biogenesis d/o)
Traumatic brain injury (with seizures starting 1 week after TBI)
Acute CNS infxn complication (meningitis or encephalitis)
Chronic CNS infection (toxoplasmosis, malaria, neurocysticercosis)
Inborn errors of metabolism (e.g., organic acidemias, phenylketonuria)
Neurodegenerative diseases (in older adults, aged 60)
Mitochondrial diseases (e.g., MELAS)
Mutations in channels or receptors (KCNQ2 or SCN1A genes)
Unresponsive
Confusion
Aphasia
Fatigue
Muscular flaccidity
Muscle pain
Headache
Hypersalivation
Ictal
Postictal
Generalized- onset seizures:
Caused by focal structural problem
Focal (formerly partial) seizures:
Prodrome: sleep/mood change, lightheadedness, anxiety, irritability, poor concentration
Loss of consciousness (sudden, without warning)
Motor: Tonic: rotated eyes, apnea, lateral tongue biting → Clonic: rhythmic muscle twitching
Bowel and/or bladder incontinence
Sudden loss of muscle tone → head drop or collapse (lasting 15 sec)
Tonic-clinic (grand mal) seizure:
Sudden blank stare, unresponsive, occurs frequently, lasts 10 seconds
+/- lip-smacking, eye fluttering, or head nodding
Involves entire hemisphere(s)
Prodrome: anxiety, fear, deja vu; lasting sec to min
Affecting temporal lobe → impaired awareness
Residual transient deficit according to affected region (often mistaken for CVA/TIA)
Focal hypoperfusion, prolonged refractory period after cell depolarization, and prolonged local inhibition → Todd paralysis: weakness / paralysis of involved limb of facial muscles
Motor: automatisms (lip smacking, blinking, tapping); atonic (loss of tone); myoclonus (twitching); clonic repetitive movement; pedaling; jumping; Jacksonian march (march of convulsions)
Autonomic (flushing, sweating)
Cognitive (dyslexia, aphasia, anomia, amnesia)
Emotional (laughing, crying, feeling fear)
Sensory: visual hallucinations); paresthesias; vertigo; auditory (ringing); olfactory (unusual / intense smells); gustatory hallucinations
↑ Upwards Arrow 24
↓ Downwards Arrow 25
→ Rightwards Arrow 26
← Leftwards Arrow 27
↔ Left-Right Arrow 29
↕ Up-Down Arrow 18