â– LECTURE OVERVIEW: Cadaveric Spasm (also termed Instantaneous Rigor) is an uncommon, dramatic postmortem state where muscles lock in contraction immediately at the moment of death, completely bypassing the primary flaccidity phase.
â– PATHOPHYSIOLOGY:
1. Physical Stress: Triggered by intense physical exertion, acute pain, or severe emotional fear immediately prior to death.
2. Low Glycogen: Rapid physical exertion depletes local glycogen and ATP pools in working skeletal muscles.
3. Sudden Death: The patient dies suddenly in a high-stress state.
4. Immediate Rigor: The already-depleted ATP pools instantly drop to absolute zero, causing immediate sarcoplasmic calcium overload. Myosin heads lock on actin at that exact split-second, preserving the final posture.
â– MICROSCOPIC PATHOBIOLOGY:
Histopathologic biopsy reveals cellular atypia, pleomorphism, lipid vacuolar engorgement, or characteristic structural inclusions (e.g., specific nuclear changes, cytoplasmic inclusions) which are diagnostic for the pathology.
â– GERIATRIC PHYSIOLOGIC ADJUSTMENTS:
Older patients display reduced physiological reserves, altered muscle-to-fat distributions, and distinct renal filtration profiles.
[HY-BOARD-1126]
🌟 Dynamic Clinical Key:
A major forensic tool used to distinguish suicide from homicide. If a victim has a suicide weapon (like a revolver or knife) clutched with extreme force in their hand, or underwater weeds clutched in a drowning victim, this indicates cadaveric spasm and confirms they were alive at the time of the event. Confirm histologic findings with immunophenotypic cell markers using flow cytometry. Always adjust therapeutic doses based on age-related glomerular filtration clearance.