Sleep seizures are medical events occurring during sleep or upon waking, involving unusual electrical activity in the brain that leads to temporary changes in movement, behavior, or awareness.
Understanding Sleep Seizures
During a sleep seizure, the brain’s electrical signals disrupt, leading to physical manifestations. Unlike awake seizures, nocturnal seizures may go unnoticed, making identification challenging. Signs someone else might notice include sudden waking, confusion upon waking, bedwetting, or tongue biting.
Physical movements range from subtle twitching or jerking to stiffening or repetitive motions of the arms and legs. Vocalizations like shouting, moaning, or crying can occur. Any seizure type can manifest during sleep, but generalized tonic-clonic seizures often involve rhythmic, whole-body jerking. Focal seizures, originating in a specific brain area, are common during sleep, particularly non-REM sleep.
Underlying Causes
The most frequent reason for nocturnal seizures is epilepsy, a neurological condition characterized by recurrent, unprovoked seizures. Many forms are sleep-related, occurring more often during certain sleep stages, particularly non-REM sleep.
Specific epilepsy syndromes are known for nocturnal prevalence. Sleep-related hypermotor epilepsy (SHE), previously nocturnal frontal lobe epilepsy (NFLE), involves frequent, brief seizures during sleep, often with complex motor movements like limb thrashing or vocalizations. This condition can have a genetic basis, with CHRNA4, CHRNB2, and CHRNA2 mutations implicated. Juvenile myoclonic epilepsy (JME) involves myoclonic jerks often occurring within hours of waking, especially after insufficient sleep. Benign Rolandic epilepsy, a common childhood epilepsy, primarily features seizures during sleep, with 70-80% occurring nocturnally.
Structural issues within the brain can create areas of abnormal electrical activity leading to seizures. Past head injuries can result in scar tissue acting as a seizure focus. Other structural abnormalities, such as brain tumors, strokes, or congenital malformations, can disrupt brain function and lower the seizure threshold.
Infections affecting the brain or its surrounding membranes can precipitate seizures. Conditions like meningitis (inflammation of membranes surrounding the brain and spinal cord) and encephalitis (inflammation of the brain) can lead to acute seizures and, in some cases, long-term epilepsy due to brain damage or scar tissue. Certain parasitic infections, such as neurocysticercosis, can form brain lesions that trigger seizures.
Metabolic or electrolyte imbalances can disrupt brain electrical stability, making seizures more likely. For example, low blood sugar (hypoglycemia) or imbalances in electrolytes like sodium can lower the seizure threshold.
Certain medications or their withdrawal can trigger seizures. Some prescription drugs may induce seizures. More commonly, withdrawal from substances like alcohol or certain sedative drugs can provoke seizures in individuals with physical dependence. Alcohol withdrawal seizures typically occur within 6 to 48 hours after the last drink and are often generalized tonic-clonic.
Lifestyle factors, while not direct causes of epilepsy, can act as triggers that lower the seizure threshold. Sleep deprivation is a recognized trigger for seizures, altering brain excitability. Stress can also make individuals more vulnerable to seizures.
Diagnosis and Management
Diagnosis begins with a detailed medical history, aided by accounts from family or partners who witnessed nocturnal events. A neurological examination assesses brain and nervous system function.
A key diagnostic tool is the electroencephalogram (EEG), which measures brain electrical activity. Specialized EEGs (sleep-deprived or prolonged video-EEGs conducted overnight) are useful for capturing sleep seizure activity. Magnetic Resonance Imaging (MRI) identifies structural abnormalities like tumors, scars, or malformations. Blood tests rule out metabolic or electrolyte imbalances.
Management of sleep seizures focuses on controlling seizure activity and improving quality of life. Antiseizure medications (ASMs) are the most common treatment, prescribed based on seizure type and individual needs, stabilizing brain electrical activity.
Lifestyle adjustments also play a role. Establishing a regular sleep schedule and ensuring adequate sleep can help reduce seizure frequency, as sleep deprivation is a known trigger. Stress management techniques can be beneficial, as stress can lower the seizure threshold. Avoiding triggers like excessive alcohol consumption is advised.
Safety measures are important for individuals experiencing seizures. These include modifying the home environment to prevent injuries (e.g., padding sharp furniture corners, using non-slip rugs), taking showers instead of baths, and ensuring someone is present during risky activities like swimming.
When to Seek Medical Attention
If you suspect sleep seizures, consult a healthcare professional, ideally a neurologist. Prompt evaluation determines the cause and guides management.
Seek immediate medical attention for:
A first-time seizure.
Any seizure lasting over five minutes.
Repeated seizures without full recovery of consciousness.
Sustaining an injury during a seizure (e.g., head injury).
Increasing seizure frequency or severity.
New or worsening symptoms with seizures.
Concerns about medication side effects.