Seizure (violent movement seizure).

Attacks of violent movements or "convulsions" may occur with loss of consciousness or against the background of an altered state of consciousness. They may also be observed with completely intact consciousness. According to their genesis, violent movements may be epileptic or non-epileptic in nature; sometimes they take the form of cramps or tetanic spasms, or manifest themselves as a picture of psychogenic seizures or paroxysms of psychogenic hyperkinesis. At first glance, they often give the impression of an "incomprehensible" syndrome. The diagnosis is facilitated if the motor pattern of violent movements is typical (for example, phases of tonic and then clonic convulsions in a typical generalized epileptic seizure; dystonic spasms in a picture of paroxysmal dyskinesias; tonic convulsions in a picture of fainting; carpopedal spasms in tetany or unusual plasticity of psychogenic movement disorders). However, violent movements during an attack are not always typical (for example, "salute" seizures or other postural reactions in the picture of supplementary epilepsy or purely tonic spasms in paroxysmal dyskinesias). In such cases, it is important to analyze the "syndromic environment" of violent movements, as well as all other features of the disease as a whole and its course, and this is of primary importance. Video recording of a seizure is extremely useful for assessing its nature.

The main forms of "convulsive" attacks:

1. Epileptic seizure.
2. Febrile seizures.
3. Paroxysmal dyskinesias.
4. Psychogenic (conversion) seizures.
5. Convulsive fainting.
6. Acute paroxysm of hyperventilation.
7. Tetany.
8. Early dyskinesia.
9. Hemiballismus attacks during ischemic infarctions or TIA.
10. Startle syndrome.
11. Transient ataxia.
12. Psychogenic hyperkinesis.

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Epileptic seizure

Typical epileptic seizures ("standard clinical model of convulsive generalized tonic-clonic seizure") are characterized by sudden onset, short (most often) duration, periodicity of occurrence, stereotypic manifestations, the presence of seizures as the main manifest sign, the presence of phases (tonic and clonic) in the seizure, and impaired consciousness. With the correct selection of the drug, the therapeutic effect of anticonvulsants is characteristic (in most cases). However, sometimes an epileptic seizure can occur without typical epileptic phases, without characteristic generalized seizures, and even with intact consciousness (for example, some types of frontal epileptic seizures). Epileptic activity is also not always detected on the EEG. The epileptic nature of the seizure is indicated by such features as the presence of postictal changes in consciousness and electroencephalogram; reaction to sleep deprivation, which allows identifying EEG signs of epilepsy; the presence of psychosensory, affective and behavioral manifestations characteristic of the ictal period of epilepsy, making the diagnosis of epilepsy undoubted. Sometimes, to confirm the diagnosis of epilepsy, polygraphic recording of night sleep or more complex methods of recording the bioelectrical activity of the cortex and subcortical structures of the brain are required. Additional indirect confirmation of the epileptic nature of the seizure is the exclusion of other possible causes of the seizure.

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Febrile seizures

Febrile seizures in children are a variant of epileptic seizures and reflect increased convulsive readiness, indicating the risk of the subsequent occurrence of typical epileptic seizures (especially with a family history of febrile seizures and epilepsy) with a progressive course. The likelihood of epilepsy increases with a high frequency of febrile seizures and especially with their status-like course.

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Paroxysmal dyskinesias

Paroxysmal dyskinesias (the outdated name is "paroxysmal choreoathetosis") are a heterogeneous group of disorders characterized by attacks of involuntary movements and pathological postures that occur without impairment of consciousness.

There are six forms of paroxysmal dyskinesia:

1. Paroxysmal kinesiogenic dyskinesia.
2. Paroxysmal nonkinesiogenic dyskinesia.
3. Paroxysmal exercise-induced dyskinesia.
4. Paroxysmal hypnogenic dyskinesia.
5. Paroxysmal benign torticollis in infants.
6. Paroxysmal dyskinesia in the picture of alternating hemiplegia in children.

Kinesiogenic attacks are provoked by unprepared movements, twitching, starting to walk, etc. Most kinesiogenic attacks are short (usually 10-20 seconds); they are characterized by a high frequency of attacks (sometimes more than 100 per day). Non-kinesiogenic attacks are provoked by emotional stress, intellectual strain, pain; they often develop spontaneously without an apparent cause. Non-kinesiogenic attacks are 100% long-term (from 1 to several hours); they occur much less frequently (from 1 per day to 1 per week or 1 per several weeks). A special form of attacks has also been identified: it is sometimes called "intermediate" because their duration is 5-30 minutes, and the attack itself is provoked, strictly speaking, not by movement, but by prolonged physical exertion.

In all forms of paroxysmal dyskinesia, in about 80% of cases, it is possible to identify certain precursors of an attack ("aura") in the form of sensations of numbness, discomfort, stiffness and tension of individual muscle groups, with which the attack itself usually begins. Kinesiogenic attacks begin in those muscles, the contraction of which provokes an attack. Usually, these are the distal parts of the arms or the muscles of the leg. Muscle spasm during an attack can spread from the arm (or leg) to the entire half of the body, including the face, and in this case is manifested by hemisyndrome. But the attack can also be generalized. It is also possible for left-sided, right-sided and generalized paroxysms to alternate from attack to attack in the same patient.

The predominant element in the structure of the motor manifestations of the attack are dystonic spasms and dystonic postures, but tonic, choreic, myoclonic, ballistic or mixed movements are possible. Similar attacks in some patients develop only during sleep (hypnogenic paroxysmal dyskinesia). Sporadic and hereditary forms of it have been described. These attacks develop only in the slow sleep phase, can be nightly and are sometimes observed up to 10 or more times per night.

Many patients with paroxysmal dyskinesias experience relief after an attack, as they know well that there will be no attack for some time (refractory period).

There is a misconception that paroxysmal dyskinesias manifest themselves exclusively with motor symptoms. An attack is usually accompanied by anxiety, worry, and a sense of fear. Permanent emotional disorders are also characteristic of the interictal period, which sometimes complicates differential diagnostics with psychogenic motor disorders.

All forms of paroxysmal dyskinesias are primary (sporadic and hereditary) and secondary. In primary forms, focal neurological symptoms are not detected in the neurological status. Possible causes of secondary paroxysmal dyskinesias continue to be clarified. Until recently, only three diseases were mentioned among these causes: cerebral palsy, multiple sclerosis, and hypoparathyroidism. Today, the etiology of this syndrome includes, in addition to the above causes, pseudohypoparathyroidism, hypoglycemia, thyrotoxicosis, cerebral infarction (including systemic lupus erythematosus), transient ischemic attacks, hemorrhage in the medulla oblongata, arteriovenous malformation, traumatic brain injury, encephalitis (in the acute phase), HIV infection, iatrogenic (cerucal, methylphenidate, cisapride) and toxic (cocaine, alcohol, etc.) forms, and some other causes (progressive supranuclear palsy, complex regional pain syndrome, spinal cord injury). Perhaps the circle of these diseases has not yet been completely closed and will expand.

EEG during an attack is usually filled with movement artifacts; in those cases where EEG recording is possible, epileptic activity is absent in most cases. It is typical that attacks usually respond to anticonvulsants (clonazepam, finlepsin, etc.).

For diagnosis, it is important to be able to recognize typical dystonic postures in the limbs, EEG examination in the interictal period and, if possible, during an attack. Sometimes video recording of the attack is useful.

In terms of motor patterns, patients with paroxysmal dyskinesia most often resemble dystonia, and in terms of the paroxysmal nature of its manifestations, they are similar to epilepsy.

Paroxysmal dyskinesias are also characterized by a sudden onset, short (most often) duration, periodicity of occurrence, stereotypical manifestations, the presence of "convulsions" as the main manifest sign and, finally, the therapeutic effect of anticonvulsants. In addition, patients with paroxysmal dyskinesias often have various deviations in the EEG and even obvious epileptic encephalographic and/or clinical manifestations in the patient's history or in their family members. The proposed strict criteria for differential diagnosis based on EEG recording of the attack itself, unfortunately, did not solve the problem, since the EEG during an attack most often reflects only motor artifacts, which require telemetric recording of bioelectrical activity to overcome. Most often, paroxysmal dyskinesias should be differentiated not from epilepsy in general, but from epilepsy of frontal lobe origin, which is distinguished by the fact that frontal seizures are often not accompanied by epileptic activity on the EEG, occur without impairment of consciousness, and are characterized by unusual motor manifestations (the so-called "pseudo-pseudo seizures", postural phenomena during an attack, etc.). In most cases, the clinical diagnosis of paroxysmal dyskinesias does not cause any particular difficulties, but there are observations when the differential diagnosis with epilepsy becomes extremely difficult. However, a similar situation is possible in the differential diagnosis with psychogenic seizures.

Indeed, paroxysmal dyskinesias differ from epilepsy by a number of features, many of which are of fundamental importance. Such features include:

• absence of phases in the seizure characteristic of a typical epileptic seizure;
• preservation of consciousness;
• absence of postictal changes in consciousness and electroencephalogram;
• features of the motor pattern that are not typical for epilepsy (for example, alternation from attack to attack of left-sided, right-sided and bilateral attacks in the same patient, or the appearance of a crossed syndrome);
• the ability to partially control violent movements during an attack is expressed more clearly than in epilepsy;
• the possibility of very accurate imitation of an attack of paroxysmal dyskinesia;
• absence of EEG changes during an attack in most cases;
• the reaction to sleep deprivation (electroencephalographic and clinical) is directly opposite in paroxysmal dyskinesia and epilepsy (activation shifts on the EEG in the first case and an increase in hypersynchronization in the second; a decrease in dyskinesia in paroxysmal dyskinesia and provocation of seizures in epilepsy).

Benign paroxysmal torticollis of infants is observed in the first year of life and manifests itself as episodes of tilting or rotating the head to one side lasting from 1 to 3 days, sometimes with pallor and a picture of distress. The indicated picture is episodically repeated up to 3-6 times a year. In these children, paroxysmal torticollis later evolves into "benign paroxysmal vertigo" or migraine. Migraine is usually present in the family history.

Alternating hemiplegia in children begins at the age of 3 months to 3 years and manifests itself in repeated attacks of hemiplegia with alternating side of paralysis. The duration of the attack is from several minutes to several days. Other paroxysmal manifestations are also characteristic: dystonia, chorea, which also occur paroxysmally. Bilateral hemiplegia is possible. Improvement of the condition during sleep is characteristic (hemiplegia disappears during sleep and returns again in wakefulness). The first attacks can be either hemiplegic, or dystonic, or a combination of both types of attacks. Attacks are often accompanied by nystagmus. Mental retardation is also characteristic of these children. Spasticity, pseudobulbar syndrome and cerebellar ataxia may be added.

Psychogenic (conversion, hysterical) seizures

In typical cases, pseudo-seizures are characterized by an emotional onset with a provoking situation or event, a bizarre pattern of "convulsions". The diagnosis is facilitated by the presence of elements of a hysterical arc in the attack (throwing back the head or lifting the chest, characteristic thrusts of the pelvis, etc.). In a hysterical attack, groans, crying, tears, laughter (sometimes these phenomena are observed simultaneously), screaming, pseudo-stuttering and other more complex vocalization and dyslalia may appear. A psychogenic attack is always characterized by a vivid vegetative accompaniment with tachycardia, increased blood pressure, symptoms of hyperventilation, less often - apnea lasting up to 1-2 minutes, and other vegetative symptoms.

The most reliable differences between psychogenic seizures and epileptic seizures are deviation from the standard model of the motor pattern of an epileptic seizure, absence of epileptic activity on the EEG during the seizure, absence of rhythm slowing in the post-seizure EEG, absence of a connection between the frequency of seizures and the concentration of anticonvulsants in the blood plasma. As a rule, positive criteria for the diagnosis of a psychogenic disorder are revealed and the so-called polysymptomatic form of hysteria occurs.

In addition, if epilepsy is suspected, to exclude (or confirm) the latter, it is important to search for other clinical and electroencephalographic evidence of epilepsy: provocation of epileptic activity by 5-minute hyperventilation, sleep deprivation followed by EEG recording, polygraphic recording of night sleep (the most reliable method), video recording of a seizure for the purpose of a detailed analysis of the motor manifestations of the seizure. It is always useful to remember that for an unmistakable recognition of the nature of the seizure, it is necessary to take into account all the components of the seizure, the interictal period and the disease as a whole. For clinical diagnostics, the most informative are the motor manifestations of the seizure.

Convulsive fainting spells

Convulsive fainting sometimes occurs in patients prone to fainting. The occurrence of convulsions during fainting indicates the depth and duration of loss of consciousness. In such cases, there may be a significant similarity between fainting and epilepsy: loss of consciousness, dilated pupils, tonic and clonic convulsions, profuse salivation, urinary and even fecal incontinence, post-seizure weakness sometimes with vomiting and subsequent sleep.

Fainting differs from epilepsy by the presence of a pre-syncope (lipothymic) state in the form of nausea, tinnitus, a premonition of an imminent fall and loss of consciousness. There are vasodepressor (vasovagal, vasomotor); hyperventilation syncope; syncope associated with hypersensitivity of the carotid sinus (GCS syndrome); cough syncope; nocturic, hypoglycemic, orthostatic and some other types of fainting. In all these cases, the patient experiences a feeling of nausea before losing consciousness, talks about dizziness and a premonition of loss of consciousness. Fainting is extremely rare in a horizontal position and never occurs in sleep (at the same time, it is possible when getting out of bed at night). With any variants of orthostatic hypotension and fainting, the patient complains of non-systemic dizziness and general weakness. In the diagnosis of fainting, it is important to take into account the orthostatic factor in their genesis. Patients suffering from fainting often have a tendency to arterial hypotension. To clarify the nature of fainting, a cardiological examination is also necessary to exclude the cardiogenic nature of fainting. The Aschner test has a certain diagnostic value, as well as such techniques as compression of the carotid sinus, the Valsalva test, 30-minute standing tests with periodic measurement of blood pressure and heart rate, and cardiac tests to diagnose peripheral autonomic failure.

Convulsions in generalized tonic-clonic epileptic seizures differ somewhat from convulsions in syncope. In syncope, they are often limited to isolated twitching. Muscle spasms in syncope begin with opisthotonus, which has nothing in common with adversive seizures in temporal epilepsy.

EEG studies are of decisive importance; however, non-specific EEG abnormalities do not indicate epilepsy and should not mislead the physician. All methods of provoking epileptic activity on the EEG are used.

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Acute paroxysm of hyperventilation

An attack of psychogenic hyperventilation leads to the development of respiratory alkalosis with such typical symptoms as mild headache, dizziness, numbness and tingling in the limbs and face, visual disturbances, muscle spasms, palpitations, fainting (or epileptic seizure). Such patients often complain of tightness in the chest, inability to take a deep breath. Aerophagia may be observed, which can lead to abdominal pain. Against the background of dyspnea, tremors and chill-like hyperkinesia, as well as tetanic spasms in the limbs, may appear. Such patients are sometimes erroneously diagnosed with "diencephalic epilepsy".

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Tetany

Tetany reflects overt or latent parathyroid gland insufficiency (hypoparathyroidism) and is manifested by a syndrome of increased neuromuscular excitability. The overt form is observed in endocrinopathy and occurs with spontaneous tetanic muscle cramps. The latent form is most often provoked by neurogenic hyperventilation (in the picture of permanent or paroxysmal psychovegetative disorders) and is manifested by paresthesia in the limbs and face, as well as selective muscle cramps ("carpopedal spasms", "obstetrician's hand"). Emotional and vegetative disorders are characteristic, as well as other symptoms of psychogenic disease (dysomnic, cephalgic and others). In severe cases, trismus and spasm of other facial muscles may be observed, as well as involvement of the muscles of the back, diaphragm and even the larynx (laryngospasm). The Chvostek symptom and the Trusseau-Bahnsdorf symptom and other similar symptoms are revealed. Low calcium levels and increased phosphorus levels in the blood are also characteristic. But normocalcemic tetany also occurs. A positive EMG test for latent tetany is revealed.

It is necessary to exclude diseases of the parathyroid glands, autoimmune processes, and psychogenic disorders of the nervous system.

Early dyskinesia

Early dyskinesia (acute dystonic reactions) refers to neuroleptic syndromes and manifests itself as more or less generalized dystonic spasms, most often in the muscles of the face, tongue, neck, axial muscles: oculogyric crises, blepharospasm, trismus, forced opening of the mouth, attacks of protrusion or twisting of the tongue, torticollis, opisthotonus crises, pseudo-Salam attacks. About 90% of acute dystonic reactions occur in the first 5 days of therapy with neuroleptics, with 50% of all cases occurring in the first 48 hours (the "48-hour syndrome". Acute dystonia is more common in young people (more often in men). It responds well to therapeutic correction with anticholinergics or spontaneously disappears after discontinuation of the neuroleptic. The temporary relationship of the syndrome with the introduction of the neuroleptic makes diagnosis not very difficult.

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Hemiballismus attacks in ischemic infarctions or TIA

Transient hemiballismus may be observed in cases of ischemia affecting the subthalamic nucleus and is manifested by a transient attack of large-scale choreic and ballistic movements on the contralateral half of the body ("hemiballismus-hemichorea"). Hemiballismus is often combined with decreased muscle tone in the affected limbs. In general, this syndrome has also been described in cases of damage to the caudate nucleus, globus pallidus, precentral gyrus or thalamic nuclei (ischemic infarctions, tumors, arteriovenous malformations, encephalitis, systemic lupus erythematosus, HIV infection, TBI, demyelination, tuberous sclerosis, hyperglycemia, basal ganglia calcification, as a side symptom of levodopa therapy in Parkinson's disease, as a complication of thalamotomy).

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Transient ataxia

Transient ataxia may sometimes mimic transient hyperkinesias. Such ataxia may be iatrogenic (e.g., during treatment with diphenin), in encephalitis in children, and in some hereditary diseases (episodic ataxia type I, episodic ataxia type II, Hartnup disease, maple syrup urine disease, pyruvate dehydrogenase deficiency). In adults, the causes of periodic ataxia may be drug intoxication, multiple sclerosis, transient ischemic attack, compression lesions in the foramen magnum, intermittent obstruction of the ventricular system.

Psychogenic hyperkinesis

For differential diagnosis of psychogenic and organic hyperkinesis it is necessary

1. positive diagnosis of psychogenic movement disorders and
2. exclusion of organic hyperkinesis.

To solve these issues, it is important to take into account all the nuances of the clinical picture, and in hyperkinesis itself, 4 factors must be assessed: the motor pattern, the dynamics of hyperkinesis, as well as its syndromic environment and the course of the disease.

The formal criteria for clinical diagnosis of any psychogenic hyperkinesis are as follows: sudden onset with a clear provoking event; multiple movement disorders; variable and contradictory movement manifestations, fluctuating during one examination; movement manifestations do not correspond to the known organic syndromology; movements increase or become more noticeable when the examination is focused on the affected part of the body and, conversely, movements decrease or stop when attention is distracted; hyperekplexia or excessive startle reactions; pathological movements (hyperkinesis) respond to placebo or suggestion, concomitant pseudo-symptoms are revealed; movement disorders are eliminated by psychotherapy or stop when the patient does not suspect that he is being observed. For each individual psychogenic hyperkinetic syndrome (tremor, dystonia, myoclonus, etc.), there are some additional clarifying diagnostic nuances, which we will not dwell on here.

The following features of hyperkinesis cannot be used as differential diagnostic criteria: changes in its severity under the influence of emotional stimuli, changes in the level of wakefulness, hypnotic suggestions, sodium amytal disinhibition, alcohol intake, changes in the posture of the body or its parts, fluctuations in the severity of hyperkinesis in the form of “bad” and “good” days.

In addition, "violent movement episodes" can also include some sleep-related phenomena: benign nocturnal myoclonus (in infants), jactation ("rocking"), restless legs syndrome, periodic limb movements during sleep (and other similar syndromes). Closely related is the behavior in night terror syndrome, somnambulism.

Some variants of stereotypy (and possibly affective-respiratory seizures) may also be included in this group.