What Is a Nocturnal Seizure?

Sleep epilepsy is a common seizure classification in the type of epilepsy. Its seizure time is in sleep. Its main clinical feature is the sudden emergence of large behavioral abnormalities during night sleep. Common symptoms include sudden seizures during sleep, mild generalized spasms, and a few cases of sleep-related aggressive behavior.

Western Medicine Name: Sleep epilepsy
Chinese Medicine Name: Sleep epilepsy
Affiliated Department: Internal Medicine-Neurology

Disease site: Brain
Main cause: Abnormal neuronal discharge
Whether to enter health insurance: Yes

Causes of sleep epilepsy

1. Genetic factors. It is prone to occur in families of patients with a history of epilepsy or congenital central nervous system or heart malformations.

2. Brain damage and brain damage: infected with virus during embryonic development, radiation exposure to other

Causes of embryonic dysplasia can cause epilepsy; birth trauma is also a major cause of epilepsy during fetal production; traumatic brain injury.

3. Other craniocerebral diseases: brain tumor, cerebrovascular disease, intracranial infection, etc.

Sleep epilepsy diagnosis

Because sleep-type seizures are during sleep, it is difficult for the EEG to capture abnormal discharges. If necessary, you can monitor abnormal discharges throughout the day through a 24-hour EEG to accurately detect abnormal discharges and assist sleep-type epilepsy. diagnosis.

In the EEG, about 30% of the cases showed abnormal discharge in the frontal zone, and about half of the cases showed only an anterior head rhythmic slow wave. In 10% of the cases, the EEG showed flattened background activity. . Epilepsy-like discharges occurred in only 11.8% of daytime awake EEG. PSG monitoring confirmed that the onset of the disease occurred during slow-wave sleep (NREM stages 2 to 4), with a small number of episodes in the awake period. More than half of the children had neuropsychiatric symptoms during the day, including difficulty waking up in the morning, fatigue, and excessive daytime sleepiness.

Studies show that about 25% to 30% of seizures occur mainly during sleep. Children with benign epilepsy with central temporal spikes (BECT), generalized tonic-clonic epilepsy during awakening, and epilepsy with slow wave sleep spikes (CSWS).

Frontal lobe epilepsy also occurs more during sleep. Typical examples are autosomal dominant nocturnal frontal epilepsy (ADNFLE), which almost all occur during night sleep. Most previous ADNFLEs were mistaken for night terrors or other sleep disorders. Its main clinical feature is a large range of abnormal behaviors during night sleep. Common symptoms include sudden eye opening, awakening, or panic manifestations during sleep, multiple dystonia or other movement disorders, and a few cases of sleep-related aggressive behavior. Frequent attacks can occur throughout the night, up to dozens of times. Some special epileptiform discharge patterns are also more common during sleep, such as the state of sustained epilepsy electrical discharge (ESES) during sleep. ESES can be seen in multiple epilepsy syndromes, such as epilepsy with persistent spikes in slow-wave sleep, BECT, Landau-Kleffner syndrome, and so on.

The understanding of sleep-related epilepsy lies mainly in the differential diagnosis of other common sleep disorders in order to avoid wrong treatment. The basic points of differential diagnosis are first to be familiar with the clinical characteristics of the above diseases. The key method for confirming the diagnosis is EEG examination, especially natural sleep EEG or long-range EEG monitoring. It is best to perform PSG examination at the same time, on the one hand, it can assist the diagnosis of general sleep disorders, and on the other hand, sleep-related epilepsy can increase the detection rate of epileptiform discharges, and help judge its relationship with the sleep cycle. In some sleep-related epilepsy, the frequency of epileptic discharges is closely related to the sleep cycle. Our study of the circadian pattern of BECT epileptiform discharge confirmed that the average frequency of release was 4.5 times / minute in the awake period, while it was as high as 27-50 times / minute in the NREM period throughout the night. ESES characteristics appeared in some cases and the REM sleep period was abnormal Discharge can reach 20 times / minute or more. Landau-Kleffner syndrome also shows a similar pattern of diurnal distribution.

In the classification of epilepsy and epilepsy syndrome published by the International Antiepileptic Coalition in 1989, some or all of the epilepsy syndromes occurred during sleep. Sleep-related epilepsy and sleep disorders such as narcolepsy, night terrors, nightmares, and OSAS have many things in common. All occur during sleep, and the performance is mostly episodic, which can be accompanied by mental retardation or abnormal behavior. However, the treatment principles are very different and the prognosis is also very different.

Sleep epilepsy confirmed

Some scholars believe that sleep-type epilepsy is an autosomal dominant inheritance. A pedigree study in Australia found that mutations in the CHRNA4 gene at 20q 13.2 to 13.3 are related to the disease. Related reported treatments include carbamazepine, clonazepam or lamotrigine. Most showed significant curative effects, with a marked reduction in the onset or even complete termination, and a reduction or disappearance of complaints of discomfort during the daytime awake period. But the final treatment method is still determined by the clinician based on the actual condition.

Once sleep-related epilepsy is diagnosed, formal antiepileptic treatment is generally required, otherwise repeated attacks may affect neuropsychiatric function. Other sleep disorders, such as night terrors and nightmares, generally do not require special treatment, and most have self-limiting characteristics. Some sleep disorders, such as narcolepsy and OSAS, require good drug or device intervention, and their prognosis is usually good.

Sleep epilepsy

1. The relationship between NREM sleep period and REM sleep period:

Many studies have found that seizures increase during NREM sleep and decrease in seizures during REM sleep. The pathophysiological mechanism may be: neurons in epileptic foci are hypersensitive to synchronized excitatory synaptic afferents during sleep, and different sleep periods have different firing thresholds, seizure thresholds, and excitability of neurons. influences. The NREM phase improves the synchronization of brain neurons through the interaction of the brainstem reticular activation system, thalamus and cortex. Epilepsy activity is generalized during this period, and epilepsy-like discharge is more obvious. The synchronization mechanism of thalamic cortex during REM phase is Inhibition results in the suppression of epileptiform discharge spread and skeletal muscle relaxation. Patients with obstructive sleep apnea syndrome have frequent sleep interruptions and reductions in NREM stages 3, 4, and REM. Severe patients frequently switch between stages 1 and 2 and awakening, which may cause seizures; meanwhile, the low Oxygenemia and insufficient cardiac output may also contribute to the attack. [1]

2. The relationship between epilepsy and circadian rhythm:

For spontaneous epileptic seizures or epileptic discharges, there is a diurnal tendency. Some seizures often occur at specific times of the day, proving that epilepsy has a certain relationship with biological rhythms. Some people in China have conducted statistical analysis on 2825 cases of major epilepsy. The results show that 33% of authors post-wake or dusk, 44% of authors post-sleep or before-wake, and the rest are random authors. Epilepsy is divided into awake epilepsy (day seizures), sleep epilepsy (night seizures), and diffuse epilepsy (no relative fixed time, also called irregular seizures). This has important guiding significance for EEG examination. For example, patients with sleep epilepsy have lower positive rate when checking EEG during the day.

3. The relationship between epilepsy and sleep:

Epilepsy is closely related to sleep interaction. Epilepsy affects sleep, the extent and extent of seizures, and the timing of seizures affect the quantity and quality of sleep. People with epilepsy usually sleep at night but lose quality. The sleep-wake cycle also affects the onset of epilepsy. Sleep disorders such as irregular sleep-wake cycles or lack of sleep can be contributing factors to sleep epilepsy. Patients with psychomotor episodes and major episodes are prone to occur at night. The causal relationship between sleep apnea and epilepsy is not very clear, but changes in sleep structure are considered to be one of the causes of seizures.

Clinical features of sleep epilepsy

1. Sleep disorders:

The relationship between epilepsy and sleep is complex, and the two affect each other. Symptoms of sleep disorders are very common in patients with epilepsy, and their manifestations are diverse and complex.

The symptoms of nocturnal seizures have a significant effect on the structure of sleep, manifested in reduced sleep efficiency and decreased number of REM sleeps, daytime seizures, anti-epileptic drugs (AEDs), poor sleep hygiene, other sleep disorders accompanied by or coexisting May have this effect. The symptoms of daytime sleepiness in patients with primary sleep disorder are more persistent and persistent, and its effective control can improve the effect of epilepsy treatment and significantly improve the quality of life. AEDs may be beneficial or harmful to sleep. Among them, benzodiazepines, phenobarbital, and phenytoin have adverse effects on sleep. According to a prospective survey of the effects of AEDs on sleep structure made by some scholars, carbamazepine has no significant effect on sleep; sodium phenytoin and valproate can increase the duration of NREM sleep and reduce SWS and REM. Sleep time; Gabapentin can increase SWS time to improve sleep. In the treatment of patients with epilepsy, we must consider these potential effects. Those with insomnia can take AEDs with sedative effects, while those with daytime sleepiness can take AEDs with excitability, so as to maintain good sleep quality for patients with epilepsy and Daytime alertness is important.

Nocturnal symptoms often appear as sudden, unexplainable awakenings, leading to complaints of insomnia, but are relatively rare. The epilepsy focus may be the cause of seizure-induced micro-awakening, and the micro-awakening shown by PSG may be the initial manifestation of the symptoms of nocturnal seizures. If seizure-induced micro-wakefulness is very frequent due to small autonomic activities at night, it is easy to produce nighttime sleep fragments, which leads to the phenomenon of daytime sleepiness in patients. Drowsiness can be exacerbated by the use of sedatives and anticonvulsants, but for patients taking anticonvulsants, if there are symptoms of daytime drowsiness, we cannot simply summarize the cause of the drug. If the PSG test found a higher The micro-awakening index usually indicates this.

2. Forms and symptoms of nocturnal seizures:

(1) Complex partial seizures:

The lesions are located in the bilateral temporal lobe and related structures such as the hippocampus and hook gyrus. The cause is not clear. There are often short-term threats, such as sound, light, phantom smell, etc., followed by gaze and drowsiness, and the following autonomic symptoms: simple and repetitive simple actions, such as pouting, licking, chewing, swallowing or fumbling, Even walking around or running. After the attack, the consciousness is unclear, and there will be some abnormal behaviors, such as self-injury, wounding, even killing, setting fire, etc., which have certain risks.

(2) Partial motor seizures:

It is usually conscious and manifests as a twitch of a part of the body, such as the corners of the mouth, the face, the muscles of the throat, the muscles of the hands, fingers, or toes. This attack can be limited to the above-mentioned starting site, occasionally spreading to the upper limbs but rarely spreading to the lower limbs, and sometimes spreads to the adjacent site or ipsilateral side, if it spreads to the contralateral side, it causes a generalized tonic attack.

(3) Systemic tonic clonic attack:

Its performance is similar to a daytime attack. Sudden loss of consciousness usually results in generalized muscle rigidity with eyeballs and dilated pupils and screams. It lasted for a few seconds and then there was a rhythmic contraction of the whole-body muscles, which gradually slowed down and ended after the last strong contraction. For 2 to 3 minutes, sweating, urinary incontinence, and bite of the tongue may occur.

(4) Nocturnal frontal lobe epilepsy (NFLE):

The focus of these patients is in the frontal orbital area and auxiliary motor area, accounting for 15% to 30% of various frontal lobe epilepsy. Divided into familial and sporadic, the study believes that familial type is an autosomal dominant genetic disease. Three gene mutation sites have been found, of which two subtypes encoding the nicotinic acetylcholine receptor -4 and -2 are present in only 10% of cases. Later, the gene on chromosome 15q24 was discovered Unrecognized, it is the third mutation site. The disease mainly occurs during deep sleep, usually with rapid onset and termination, and can manifest the following symptoms: Behavioral symptoms: Patients with strange behaviors, such as running and shouting, are often mistaken for awakening or misdiagnosed as sleepwalking , REM sleep behavior disorder (RBD) and so on. Symptoms of sleep movement: manifested as nocturnal limb movement with tonic spasm, which may appear rolling or kicking movements. Video recording can find that the abnormal motor symptoms accompanying the onset of the disease are of characteristic value for diagnosis.

(5) focal epilepsy in benign children:

Usually there are paresthesias in the tongue, lips, gums, etc., or tonic or tonic spasms of the face, lips, tongue, and pharynx muscles, and saliva flows out. Occipital epilepsy in children has the characteristics of clinically typical triads, including nocturnal seizures, eye spasm, deflection, and vomiting. EEG features are characterized by repetitive spikes and slow waves in the occipital region, which can be induced by closed eyes and darkness. The frequency of onset is low, and the age of onset is usually 3 to 5 years. In addition, pure tonic seizures may be a kind of epilepsy syndrome similar to benign children with focal epilepsy. They may have complaints of insomnia or drowsiness. Examination revealed micro-awakening or micro-awakening of multiple spikes.

PSG Characteristics of sleep-type epilepsy PSG examination

1. The characteristic abnormality of partial seizures is transient localized sharp waves or spikes, usually the discharge activity of NREM sleep period is activated, and occasionally occurs during the transition from REM sleep period to arousal. This discharge activity can be limited, or it can spread to adjacent tissues, sometimes secondary to extensive attacks. The continuous measurement of power spectrum (LDP) during deep sleep shows that the characteristics of spike spikes are: it appears in the high level of LDP, it is more likely to occur in the rising phase, especially the rapid rising phase, and the frequency of NREM sleep is The frequency of the REM period was on average 4.6 / min higher.

2. Tonic-clonic seizures are characterized by bilateral synchronous spine-slow complex waves, as well as symmetrical spike waves and multiple spine-slow complex waves. The occurrence frequency of sharp wave and compound slow wave is 2.5 ~ 3Hz or 4 ~ 5Hz, and it usually appears in groups within 1 ~ 4 seconds. NREM usually appears more easily, mainly multi-spike complex waves, and appears fragmented due to the appearance of abnormal waveforms. Seizures appear as low-voltage fast-rhythmic electrical activity. After the attack, the EEG activity was significantly suppressed, showing slow wave activity. Focal or unilateral cusps can be manifested as part of general paroxysmal disease. The frequency of occurrence in the REM phase was significantly suppressed or even disappeared.

3. In benign children with focal epilepsy, a high-amplitude negative-phase sharp wave is a characteristic manifestation. Spikes appear in multiple parts of the central-temporal zone, and the onset is more obvious during NREM sleep.

Sleep epilepsy considerations

1. Taboo tobacco, alcohol, tea, coffee, chocolate, Coca-Cola and other foods and beverages containing a lot of caffeine.

2. Don't watch TV (especially thrilling, fearful, exciting, sad movie and TV programs). Don't play chess, do not play mobile phones, poker, mahjong, computers, video game consoles.

3. It is forbidden to operate at high altitude, even if the vehicle, operating rotating machinery and frequent contact with water, fire, electricity, etc.

4. Don't be overworked, excited, angry, pay attention to rest.

5. Can not abruptly stop taking anti-disease drugs to avoid causing epilepsy status.

6. Overcome inferiority and fear, and avoid emotional stimuli such as fatigue and tension.

7. Strengthen physical fitness, regular living, taboos and other irritating foods are contraindicated.

8. It is strictly forbidden to drive and swim, go out alone at night, and other activities. If there is an omen, you should lie down immediately to avoid falls.