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2R.N. Muhiddinzoda, J.J. Bakhronov, S.Z. Ubaydullayev, M.M. Kuddusov, Sh.B. Kuchkorov, M.N. Nigmatullaev, Sh.B. Jamoliddinov, Sh. V. Kakharov
CLINICAL MANIFESTATION OF LENNOX-GASTAUT SYNDROME
Lennox-Gastaut syndrome (LGS) is an epileptic encephalopathy, starting in childhood and showing in often polymorphic seizures (including tonic axial ones), severe cognitive deficite, slow activity of the acute-slow wave in the interictal period at the electroencephalography (EEG), runs of fast activity of 10-20 Hz, often associated with tonic seizures, as well as with the resistance to therapy. According ILAE Classification of epilepsy syndromes and epilepsies 1989 LGS was referred to generalized cryptogenic or symptomatic forms of the epilepsy. According to Proposed Diagnostic Scheme for People with Epileptic Seizures and with Epilepsy (2001) LGS is a classic representative of the group of childhood epileptic encephalopathies. LGS is a rather rare form of the epilepsy. The syndrome frequency makes from 1-4 to 6.6 % among allforms of the childhood epilepsy. LGS is subdivided into the cryptogenic and the symptomatic variants.
Key words: epilepsy, Lennox-Gastaut syndrome, cryptogenic, symptomatic, etiology, classification, epileptic seizure, treatment.
Lennox-Gastaut syndrome (LSS) is an epileptic encephalodromopathy with a debut at an early age, manifested by frequent polymorphic seizures (tonal-axial seizures), severe cognitive impairment, slow acute-slow wave activity in the interictal period on the electroencephalogram (EEG), runs of activity 10 - 20 Hz associated with tonic attacks and resistance to therapy.
According to the 1989 classification, PSH belonged to generalized cryptogenic or symptomatic forms of epilepsy. According to the Draft Classification 2001, LSS is a classic representative of the group of childhood epileptic encephalopathies.
SLH is certainly a heterogeneous disease, which is a specific clinical and EEG symptom complex of various etiologies. The definition of LSH implies very broad and amorphous criteria for the disease, and also contains many controversial points.
Recent studies using functional MRI have shown that PSH is a special form of epilepsy, in which many parts of the central nervous system are involved in the pathological process: the cortex, subcortical structures (especially the thalamus), the brain stem.
Symptoms. PSH is a relatively rare form of epilepsy. The frequency of occurrence ranges from 1-4 to 6.6% among all forms of epilepsy in children. SLH is subdivided into cryptogenic and symptomatic variants. The latter, from our point of view, is more correct to refer to the SFE with the phenomenon of IBS on the EEG. Currently, there is a clear trend in relation to PSH: the incidence (newly diagnosed cases) and the prevalence of the disease are decreasing every year. This is by no means due to a true decrease in the incidence, but to more stringent criteria for diagnosing this disease. The etiology of PSH can be cortical development disorders, perinatal encephalopathies, brain tumors, encephalitis, hereditary metabolic diseases, chromosomal abnormalities, and other factors. In the classical cryptogenic variant of LGS, the etiology remains unknown.
In 1939 F.A. Gibbs, E.L. Gibbs and W.G. Lennox described slow peak-wave complexes on the EEG. They delimited this activity from faster peak waves with a frequency of 3 Hz during petit mal absences, designating it as petit mal variant. In 1949 W.G. Lennox and J. Davis for the first time presented a detailed description of the clinical picture of epilepsy in patients of 2 different categories: with fast and slow generalized peak-wave activity on the EEG, which is officially considered the time of the emergence of a new syndrome - epilepsy with petit mal variant on the EEG. In 1966, the Marseilles group published the first clinical and EEG criteria for Lennox syndrome:
1) frequent tonic seizures and absences of the petit mal variant type;
2) mental retardation;
© R.N. Muhiddinzoda, J.J. Bakhronov, S.Z. Ubaydullayev, M.M. Kuddusov, Sh.B. Kuchkorov, M.N. Nigmatullaev, Sh.B. Jamoliddinov, Sh.V. Kakharov, 2023.
3) EEG anomalies in the interictal period with pseudorhythmic diffuse slow peak wave complexes with a frequency of 1.5-2 per second.
The disease debuts at the age of 2 to 8 years. Peak onset occurs in preschool age: 3-5 years. In the symptomatic form, an earlier onset is noted than in the cryptogenic one. In 20-40% of cases, LSS is transformed from West syndrome. Febrile seizures precede the development of LSS in 10% of cases.
The most precise, concise and simple criteria for SLH are presented by A. Beaumanoir and Ch. Dravet (1992). They are based on Lennox's classic triad of seizure patterns, cognitive impairment, and EEG data:
1) epileptic seizures: axial tonic, atonic and atypical absences;
2) EEG disturbances: discharges of diffuse slow peak-wave complexes in wakefulness (petit mal variant), runs of fast rhythmic waves, slow polyspikes, as well as generalized fast activity with a frequency of about 10 Hz during sleep;
3) status: mental retardation in combination with behavioral disorders.
The semiology of seizures in LSS is extremely diverse. The following types of seizures make up the clinical picture of SLH: tonic axial; myatonic; atypical absences; status epilepticus (ES) of small motor seizures; myo-clonic; generalized convulsive; focal.
Tonic seizures constitute the ictal nucleus and, according to most authors, an obligate clinical symptom of LSS. There are the following types of tonic seizures in SLH:
1)1) in accordance with the involvement of various muscle groups: tonic axial (with the involvement of the muscles of the body); axorizomelic (torso + limb belts); global (general muscle tension);
2) according to clinical manifestations: tonic-vegetative (tonico-autonomous); tonic with automatisms (tonic-automatic); tonic-vibrator (with a small clonic component); tonic spasms (bilateral tonic seizures lasting no more than 2 s); small motor (very short tonic attacks, accompanied mainly by tension in the muscles of the face, neck or shoulder girdle: slightly opening the eyes, grimace, shrugging the shoulders, etc.).
The most characteristic are tonic axorizomelic seizures involving the muscles of the trunk, limb belts, neck, and face. Manifested as bilateral spasms with a sudden nod; body tilt; lifting, spreading and stretching the arms forward. Usually they are short-lived (about 10 s) and are accompanied by a complete loss of consciousness. Typical occurrence of tonic seizures in the slow phase of sleep. In sleep, they can be very short (small motor ones), for example, in the form of opening the eyes, stretching, grimace (tension of the facial muscles), shrugging the shoulders for 1 -2 s. Global tonic seizures usually result in severe sudden falls in traumatized patients.
Atypical absences are manifested by a short-term change in consciousness without falls and convulsions. The level of consciousness fluctuates throughout the attack, and in some cases, patients are able to give a monosyllabic answer to a question or follow simple commands. The onset of seizures and their end is more gradual than with typical absences. During attacks, there is a confused look, hypomia, the mouth is half open; slight twitches of the facial muscles, eyelids, lips and short nods are noted. In the structure of atypical absences, a myoclonic or atonic component is often observed. The duration of attacks is from 5 to 30 s; frequency - many times a day, especially in the period after waking up.
Epileptic seizures of falls in PSH are diverse in mechanism. According to the International League Against Epilepsy (ILAE), epileptic seizures of falls are caused by a sudden change in muscle tone, leading to falls, after which patients immediately rise on their own. According to classical clinical and EEG studies, the following variants of these seizures in SLH are distinguished: purely atonic; myoclonic-atonic (myatonic); myoclonic; tonic.
Modern studies using polygraphic recording (simultaneously EEG, video and electromyography) prove the complex nature of epileptic falls in patients with LSS with the inclusion of both atonic and myoclonic components. This type of seizure is called myatonic. At the same time, the initial component of the fall is due to active myoclonus with a start, lifting of the shoulders and a short incomplete squat. It is followed by a component of negative myoclonus (actually the phenomenon of atony), which leads to the fall of patients. In myatonic seizures, the initial myoclonic component is barely noticeable, the cascading squats are very short, and one gets the impression of a completely sudden fall. Having fallen, patients immediately rise and continue the interrupted action.
Seizure polymorphism is a hallmark of LSS. In almost all cases, patients have more than 1 type of seizures, in most cases - more than 2 types. The most typical combinations of tonic axial seizures, atypical absences and falls in combination with ES.
Bibliography:
1.Capovilla G., Verrotti A. Lennox-Gastaut syndrome: nosographic limits and long-term outcome. In: Outcome of childhood epilepsies. F. Arts et al. (eds.) UK: John Libbey Eurotext, 2013. P. 121-32.
2.Arzimanoglou A., Guerrini R., Aicardi J. Aicardi's epilepsy in children. 3rd ed. Philadelphia: Lippincott, 2004. Pp.
38-50.
3.Baldy-Moulinier M., Touchon J., Billiard M. et al. Nocturnal sleep studies in the Lennox-Gastaut syndrome. In: The Lennox-Gastaut syndrome (Neurology and neurobiology, Vol. 45). E. Niedermeyer, R. Degen (eds.). N.-Y.: Alan R. Liss, 1988. Pp. 243-60.
4.Beaumanoir A., Mira L. Secondary bilateral synchrony: significant EEG pattern in frontal lobe seizures. In: Frontal lobe seizures and epilepsies in children. A. Beaumanoir, F. Andermann, P. Chauvel et al. (eds.) Paris: John Libbey Eurotext, 2003. Pp. 195-205.
5.Beaumanoir A., Blume W.T. The Lennox- Gastaut syndrome. In: Epileptic syndromes in infancy, childhood and adolescence. 4th ed. J. Roger, M. Bureau, Ch. Dravet et al. (eds.). John Libbey, 2005. Pp. 125-48.
6.Blume W.T. Pathogenesis of Lennox- Gastaut syndrome: considerations and hypotheses. Epileptic Disord 2001;3(4):183-96.
7.Bonanni P., Parmeggiani L., Guerrini R. Different neurophysiologic pattern of myoclonus characterize Lennox-Gas-taut syndrome and myoclonic astatic epilepsy. Epilepsia 2002;43(6):609-15.
MUHIDDINZODA RUKHSHONABONUNUMONKIZI - student of the 221st group of the medical faculty of the Samarkand State Medical University, Samarkand, Uzbekistan.
BAKHRONOV JAKHONGIR JASUROVICH - student of the 521st group of the pediatric faculty of the Samarkand State Medical University, Samarkand, Uzbekistan.
UBAYDULLAEVSARDOR ZAFAROVICH - student of the 507th group of the pediatric faculty of the Samarkand State Medical University, Samarkand, Uzbekistan.
KUDDUSOVMUSLIMBEK MUHSIN UGLI - student of the 522th group of the pediatric faculty of the Samarkand State Medical University, Samarkand, Uzbekistan.
KUCHKOROV SHAKHZODBEK BAHODIROVICH - student of the 521st group of the pediatric faculty of the Samarkand State Medical University, Samarkand, Uzbekistan.
NIGMATULLAEV MUHAMMADJON NURALIYEVICH - student of the 522st group of the pediatric faculty of the Samarkand State Medical University, Samarkand, Uzbekistan.
JAMOLIDDINOVSHERALIBAXTIYOR UGLI - student of the 507th group of the pediatric faculty of the Samarkand State Medical University, Samarkand, Uzbekistan.
KAKHAROVSHAKHRIYOR VALIJONOVICH - student of the 507th group of the General Medicine of the Samarkand State Stomatology Institute, Tashkent, Uzbekistan.
