risus sardonicus
Tetanus facial spasm
Risus sardonicus is a sustained, involuntary grinning expression caused by prolonged spasm of the facial muscles.
The term comes from Latin for "sardonic laugh" and appears almost exclusively in medical contexts, particularly describing a classic symptom of tetanus.
The expression resembles a grimace or pained smile rather than genuine amusement: The patient presented with risus sardonicus and muscle rigidity.
Muscle-stiffening bacterial disease
- lockjawSustained jaw muscle spasm
- neurotoxinPoison attacking neural tissue
- botulismBacterial food poisoning
- toxicityCapacity to cause harm
intoxication · opisthotonus · respiratory failure · hypocalcemia · tetany · haloperidol · anticholinesterase · water hemlock
Sudden involuntary muscle contractions
- dystoniaMovement disorder causing postures
- contractionReduction in size
- myoclonusSudden brief muscle jerks
- spasticityPathological muscle tightness
clonus · hypertonia · fasciculation · twitching · cramp · rictus
Medical evaluation of body
- differential diagnosisSystematic comparison of possible conditions
- case studyResearched particular instance
- symptomatologyStudy of disease manifestations
- medical historyRecord of past ailments
tetanus
Muscle-stiffening bacterial disease
- lockjawSustained jaw muscle spasm
- neurotoxinPoison attacking neural tissue
- botulismBacterial food poisoning
toxicity · intoxication · opisthotonus · respiratory failure · hypocalcemia · tetany · haloperidol · anticholinesterase · water hemlock
convulsion
Sudden involuntary muscle contractions
- dystoniaMovement disorder causing postures
- contractionReduction in size
- myoclonusSudden brief muscle jerks
spasticity · clonus · hypertonia · fasciculation · twitching · cramp · rictus
grimace
Twisted expression of displeasure
- death maskMold of deceased's face
physical examination
Medical evaluation of body
- differential diagnosisSystematic comparison of possible conditions
- case studyResearched particular instance
- symptomatologyStudy of disease manifestations
risus sardonicusmuscle relaxation
Softening of contracted fibers
facial paralysis · flaccid paralysis · hypotonia · Bell's palsy · resting face