What Is Nocturnal Myoclonus, The Involuntary Spasms When Falling Asleep, Its Possible Causes, And When To Seek Medical Help.
Were you just about to fall asleep and felt a sudden jerk in your muscles, as if you were falling? This phenomenon is called nocturnal myoclonus, an involuntary spasm that usually occurs during the transition from wakefulness to sleep.
It can affect one muscle or several at the same time, causing small hallucinations or the sensation of falling, causing the person to wake up startled.
Despite being surprising, nocturnal myoclonus is common and, in most cases, harmless.
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It can occur both at home and in public transport, and in some people, it happens several times a minute.
Children and newborns are the most affected, but spasms can persist into adulthood.
How Does Nocturnal Myoclonus Work?
Experts still do not have a definitive explanation, but studies suggest that the spasms originate in the same brain system that controls the startle reflex.
One theory suggests that as the muscles relax when falling asleep, the brain mistakenly interprets that the body is falling and triggers a sudden contraction.
Another hypothesis is that the spasms are a physical reaction to the images that appear in dreams, creating involuntary movements even before deep sleep begins.
Nocturnal Myoclonus At Different Ages
In newborns, nocturnal myoclonus is common and usually disappears between two and four weeks of life, without the need for intervention.
However, parents and doctors may confuse it with epileptic seizures.
In older children and adults, spasms can still occur but tend to be less frequent.
When Can Myoclonus Indicate Health Problems
In most people, nocturnal myoclonus is physiological and poses no risk.
However, it can be a symptom of more serious medical conditions, such as:
- Neurological disorders: Parkinson’s, Alzheimer’s, epilepsy, and multiple sclerosis;
- Brain or spinal cord injuries;
- Aftereffects of stroke;
- Infections such as herpes and Lyme disease;
- Certain types of cancer, such as leukemia, lymphoma, and neuroblastoma;
- Use of specific medications, including opioids, antidepressants, and antipsychotics.
Additionally, sleep disorders such as juvenile myoclonic epilepsy, Lennox-Gastaut syndrome, restless legs syndrome, fasciculations, and periodic limb movements during sleep can manifest similarly.
When To Seek Medical Help
Treatment is only necessary if the spasms interfere with sleep or daily routine.
In such cases, a specialist doctor can assess the situation and indicate the appropriate diagnosis, as well as propose potential solutions to reduce the episodes.
Although there are still no definitive answers about its causes, nocturnal myoclonus continues to be studied, helping to better understand how the brain operates during the transition from wakefulness to deep sleep.
With information from Revista Galileu.

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