Myoclonic jerks are involuntary muscle twitches, often concerning when observed in seriously ill individuals or those nearing the end of life. Understanding their nature and potential causes can provide clarity. This article explores what myoclonic jerks are, why they occur at the end of life, how comfort can be supported, and what these movements might signify.
Understanding Myoclonic Jerks
Myoclonus refers to sudden, brief, involuntary twitching or jerking of a muscle or group of muscles. These movements are a symptom, not a disease, and can range from mild, isolated occurrences to widespread episodes. Many people experience myoclonic jerks in common, harmless situations, such as hypnic jerks when falling asleep, or hiccups.
Myoclonic jerks arise from disruptions in the nervous system, originating in the brain, spinal cord, or peripheral nerves. These disruptions lead to either sudden muscle contractions (positive myoclonus) or brief losses of muscle tone (negative myoclonus). While often benign, persistent or widespread myoclonus can indicate underlying neurological issues.
Myoclonus at the End of Life
Myoclonic jerks frequently appear in individuals nearing the end of life due to systemic and neurological changes. These movements often signal significant decline in body function. Common reasons include metabolic imbalances, such as kidney or liver failure, which cause toxins to build up and affect brain function. Hypoxia, or a lack of oxygen to the brain, can also trigger myoclonus, especially after cardiac arrest.
Medication side effects are another frequent cause. Opioids, commonly used for pain management in palliative care, can lead to myoclonic jerks due to metabolite accumulation, particularly with impaired kidney function. Other medications, including certain antibiotics and antidepressants, can also contribute. Direct brain changes from neurodegenerative diseases like Alzheimer’s or Parkinson’s, or brain tumors, can also manifest as myoclonus in advanced illness.
Supporting Comfort
When myoclonic jerks occur, the focus is on ensuring comfort and safety. While these movements can be distressing for family members to witness, they are often not painful to the person experiencing them. Non-pharmacological approaches involve gentle repositioning to prevent injury and maintaining a calm, quiet environment, as external stimuli like noise can trigger or worsen jerks.
Pharmacological interventions may be considered if jerks are frequent, severe, or causing distress. Healthcare providers may first review and adjust contributing medications, such as opioids, or consider switching opioid types. Benzodiazepines, like clonazepam or lorazepam, are often used to control myoclonus by calming the nervous system. Anti-seizure medications or muscle relaxants might also be prescribed to reduce the frequency and intensity of the jerks.
What Myoclonic Jerks May Signify
Myoclonic jerks at the end of life are typically part of broader physiological deterioration, rather than an isolated indicator of immediate death. Their presence often reflects significant systemic decline, such as organ failure or severe brain injury due to oxygen deprivation. While common in the final stages of life, myoclonus alone does not always pinpoint the exact timing of death.
Medical professionals consider these movements alongside other symptoms, such as changes in breathing patterns, decreased responsiveness, and overall functional decline, to assess prognosis. Severe myoclonus, particularly after anoxic brain injury with specific EEG patterns, has historically been associated with a poor prognosis, though therapeutic hypothermia has introduced variability. Ultimately, the focus remains on comfort and dignity, recognizing these movements can be a natural, though unsettling, part of the dying process.