BACKGROUND: The study of epidemiology of hereditary neurological diseases in Mongolia began a few years ago. Itcovered a few aimags (provinces) (D.Baasanjav, 2000-2005). Previous studies have shown, that hereditary neurologicaldiseases are not rare in Mongolia and structure and prevalence of these diseases vary by aimags. Mo n g o l i ahas 21 aimags (administrative provinces), each with a population from 45000 till 110440. In some “isolated” populationsspecific neurological hereditary diseases can be marked as “indigenous”. So the epidemiological study of hereditaryneurological diseases in Mongolia is one of the urgent medical shortcoming in Mongolia.MATERIAL AND METHOD: We used descriptive epidemiological method for revealing hereditary neurological diseases infamilies in population of 8 provinces (aimags) of Mongolia, Bayan-Ulgii, Bayankhongor, Govi-Altai, Zavkhan, Dundgobi,Khentii, Orkhon, Uvurkhangai, total of 627,000 population. The population of these aimags fluctuated in the range from47959 (Dundgobi) to 110440 (Uvurkhangai). Diseases were diagnosed by neurologists using clinical and genealogicalmethods.RESULTS: The study revealed 77 patients in 40 families in the studied population with variety of neurological hereditarydiseases. The overall prevalence of hereditary neurological diseases for 100,000 population is 12,26. The prevalencevaries by aimags from 2,08 (Dundgobi) to 32,50 (Gobi-Altai) per 100.000 population. The prevalence and their rangeby nosological structure per 100000 population in aimags are: myotonic dystrophy 5.41 widely varying by aimags: from4.66 in Bayankhongor to 27.09 in Gobi-Altai; Charcot-Marie-Tooth syndrome 1.59 and ranging from 2.08 in Dundgobito 4.66 in Bayankhongor; Duchenne muscular dystrophy -0.79 and ranging from 0.90 in Uvurkhangai to 3.19 in Bayan-Ulgii; the limb girdle muscular dystrophy -0.95 and ranging from 1.81 in Uvurkhangai to 4.66 in Bayan-Ulgii; Strumpellfamilial spastic paraplegia -0.95 for total pop and ranging from 2.71 in Uvurkhangai to 5.41 in Bayankhongor; familialparoxysmal myoplegia -0.79 for total pop. and range from 2.22 in Orkhon to 5.41 in Gobi-Altai; spinocerebellar ataxia -0.47 for total pop. (3.91-in Zavkhan); bulbo-spinal amyotrophy -0.32(only in Bayankhongor); spinal amyotrophy of adults-0.16(only in Uvurkhangai); arthrogryposis with myodystrophy -0.63 (only in Khentii); kyphoscoliosis with myodistrophyand nanism -0.16 (1.06 in Bayan-Ulgii)A comparatively high prevalence of all neurological hereditary diseases per 100.000 pop. was established in Gobi-Altai(32.50), Orkhon-26.56, Bayankhongor-15.16, Bayan-Ulgii -11.70 rates; the low prevalence - in Dundgobi-2.08 and-Zavkhan-3.91.The hereditary neuromuscular diseases among all hereditary neurological diseases taken up 71.9% i.e 55 patients from29 families. The myotonic dystrophy is tops the list of neuromuscular diseases (61.8%)CONCLUSION: Hereditary neurological diseases have a relatively high prevalence among the population of Mongolia,specially the neuromuscular diseases; so the control of these diseases in the country is one of the special priorityproblem of the national health care.

BACKGROUND: Multiple sclerosis is spreading in population of Mongolia last 30 years. But there are rare of the date ofprevalence of this disease in Mongolia. So we have studied the prevalence of this disease in population of 8 provinces(aimags) of Mongolia in 2008 year.GOAL: To reveal and establish prevalence and clinical characteristic of multiple sclerosis (MS) in population of 8 aimags(provinces) of Mongolia.METHOD: Revealing of patients with multiple sclerosis in population was made by neurologists, which are possessedof clinical method for revealing or confirm the diagnosis and were taken in register the patients only with confirmeddiagnosis. This study was conducted in following 8 aimags of Mongolia: Bayan-Ulgii, Bayankhongor, Gobi-Altai,Dundgobi, Uvurkhangai, Zavkhan, Khentii, and Orkhon; total population of these aimags is 627762 (m-306482, f-321279). The prevalence of this disease was calculated for 100.000 populations.RESULTS: There have been revealed total 35 patients in 8 aimags. The prevalence for 100.000 population is 5,57 (m-2,61; f-8,40) and has been fluctuated in provinces in range from 1,81 (Uvurkhangai aimag) till 13,28 (Khentii aimag) for100 000 population.The rest 6 provinces (aimags) have prevalence in range from 4,17 (Dundgobi) till 6,38 (Bayan-Ulgii).All patients were distributed by clinical characteristic in next main forms:Cerebro-spinal form in 22 patients (62,8%) among them optico-myelitis in 9 cases (40,9%); Spinal form in 6 patients(17,1%); Cerebral form in 4 cases (11,4%); only optical form in 3 cases (8,6%).Pure spinal, cerebral and optic forms are diagnosed in patients, which have duration of disease no more 6-7 years.By the courses of disease all patients distributed in courses the beginning with acute attack incomplete recovery(remissions) revealed in 18 patients (51,4%), more rapid but steadily progressive course in 5 cases (14,3%), acutesevere attacks course in 5 patients (14,3%).CONCLUSION:1. Multiple sclerosis is spreading in population of Mongolia in last 30 years after 1980.2. The prevalence of this disease in population of 8 provinces (aimags) of Mongolia in 2008 year is 5,57 cases (inmen-2,61; in women-8,40) for 100.000 population. The rates of prevalence of the disease by aimags are oscillated inrates from 1,81(Uvurkhangai) till 13,28 (Khentii) for 100.000 population.3. The women suffered more in 3 time than in man and optic form revealed in 34,2 % cases (in 12 patients). Theage of beginning of the disease was fluctuated in age from 16-19 years old till 60 above years old.4. By level of prevalence of this disease Mongolia now is belonging to countries of the world, which have lowprevalence of this disease (till 10 per 100.000 pop).

Background: The data of prevalence of epilepsy in rural provinces among general population in Mongolia is rare. Goal:The study aimed to identify prevalence rate of epilepsy and its characteristics by age and sex among the population in eight provinces (Bayan-Ulgii, Bayankhongor, Gobi-Altai, Zavkhan, Uvurkhangai, Dundgobi, Orkhon and Hentii) of Mongolia.Material and Мethod: This study in the listed aimag populations was carried out by retrospective application and using a questionnaire developed according to a methodology approved by the Academic Council of the Medical Science Institute. For verification of the epilepsy diagnosis, the study based on neurologist examination and EEG. In some suspect cases we used neuroradiological tests including СT and MRI. The diagnosed patients were registered using a special form. The study involved diagnostic examinations of 627762 (306482 males; 321280 females) persons that had at least two unprovoked seizures in their lives. For each case of positive diagnosis we calculated the prevalence rate per 1,000 population in each category of extended age groups (1-12 months, 1-2, 3-4, 5-6, 7-8, 9-10, 11-12, 13-15, 16-17, 18-22, 23-27, 28-32, 33-37, 38-42, 43-47, 48-52, 53-59, and above 60) and by sex.Result: There were 1407 cases (785 males; 622 females) of diagnosed epilepsy among the studied population. The cumulative prevalence rate for all aimags was studied 2,24 (males- 2,56; females-1,93) per 1,000 population. The relatively high prevalence rates per 1,000 population were observed in Gobi-Altai (5,14), Dundgobi (3,31), and Orkhon (2,48) whereas the lowest rate was in Bayankhongor (1, 38). A differential look by sex reveals a high sex gap 6,20 for males and 4,12 for females in Gobi-Altai while Dundgobi (males- 3,84; females- 2,80), Orkhon (males-2,91; females-2,08); Uvurkhangai (males -2,20; females -1,73) show little difference by sex (P>0,05).As for the differences by the detailed age groups, all aimag data shows that prevalence for males ranges between 0,14(1- 12 months) and 5,17 (48-52) and for females between 0,24 (above 60) and 3,82 (38-42). The highest prevalence rate among male population was observed in 48-52 age group, 6,21/1000; followed by age groups 33-37 (2,93/1000); 53-59 (2,84/1000); 38-42 (2,81/1000); and 18-22 (2,38/1000). The highest prevalence rate among female population was observed in 43-47 age group 5,49/1000 followed by 38-42 (5,48/1000); 33-37 (4,0/1000); 53-59 (3,35/1000).Epilepsy prevalence in age groups younger than 11-12 tends to fall for both male and female population. Gender difference in prevalence is that males tend to have higher rates 2,56 than females 1,93 ( P<0,05).Conclusion:1. The general epilepsy prevalence among some rural populations in Mongolia is 2,24 (M -2,56; F-1,93) per 1,000 population.2. The cumulative by all studied aimags data reveal relatively high prevalence rate in age groups of 18-59. This level might be related to men’s vulnerability to traumas and factors of vascular origins while in women it might relate to their physiological transformations of pregnancy delivery and menopause.3. Epilepsy prevalence in age groups under 12 years old tends to fall for both male and female population which might be related to the low level of examination and diagnosis of these diseases among children.4. Compared to some foreign scholars’ data, Mongolia’s epilepsy prevalence rate does not qualify it among the high rate countries.

BACKGROUND:Our previous study has shown that the prevalence and structure of the neurohereditary diseaseswere different by provinces and some form of these diseases as “indigenous” in some isolatedpopulation. There are some scientific results of our researches–genetics about consanguineous,which is more potential factor of community is some area of Mongolia. All these circumstance isgiving to carry out this study.MATERIALS AND METHODS:We used descriptive epidemiological method for revealing hereditary neurological diseases in thepopulation of 6 provinces (aimags) of Mongolia: Dornogobi (Easth-gobi), Sukhbaatar, Gobisumber,Central aimag, Bulgan, and Darkhan-Uul. Total population of these provinces is 363072. Thenumber of population in 6 provinces was fluctuated in the range from 15.000 (Govisumber) to 88.875(Darkhan-Uul). Prevalence was accounted for 100.000 populations.RESULTS:The prevalence of neurohereditary diseases makes up 17.08 cases per 100.000 populations amongthese 6 provinces. 79% of these are hereditary neuromuscular diseases i.e 49 patients from 29families. Myotonic dystrophia and genetic neuropathies Charcot-Marie-Tooth have comparativehigh prevalence over test forms of disease.The high rate neurohereditary diseases was established in the population of Bulgan (35.80•10-5),Sukhbaatar (31.17•10-5), and Dornogobi (21.33•10-5) provinces. Their prevalence’s prevailed in the7-10 times over rates Darkhan-Uul, 3-5 times over rates of Gobisumber aimags.No neuromuscular forms of neurohereditary diseases i.e spastic paraplegia (11.3%) andspinocerebeller ataxia (9.68%) accounts for 21% among all forms of neurohereditary diseases.The prevalence of neuromuscular diseases in the population of these six provinces is two times highthen the average rate of the population of Russia (1980 years). First reason is may be associatedwith high predisposition of based on consanguineous through reproductive way in some of theseprovinces of Mongolia.

Background: Our previous study has shown that the prevalence and structure of the neurohereditary diseases were different by provinces and some form of these diseases as “indigenous” in some isolated population. There are some scientific results of our researches–genetics about consanguineous, which is more potential factor of community is some area of Mongolia. All these circumstance is giving to carry out this study.Materials and Methods: We used descriptive epidemiological method for revealing hereditary neurological diseases in the population of 6 provinces (aimags) of Mongolia: Dornogobi (Easthgobi), Sukhbaatar, Gobisumber, Central aimag, Bulgan, and Darkhan-Uul. Total population of these provinces is 363072. The number of population in 6 provinces was fluctuated in the range from 15.000 (Govisumber) to 88.875 (Darkhan-Uul). Prevalence was accounted for 100.000 populations.Results: The prevalence of neurohereditary diseases makes up 17.08 cases per 100.000 populations among these 6 provinces. 79% of these are hereditary neuromuscular diseases i.e. 49 patients from 29 families. Miltonic dystrophia and genetic neuropathies Charcot-Marie-Tooth have comparative high prevalence over test forms of disease.The high rate neurohereditary diseases was established in the population of Bulgan (35.80•10-5), Sukhbaatar (31.17•10-5), and Dornogobi (21.33•10-5) provinces. Their prevalence’s prevailed in the 7-10 times over rates Darkhan-Uul, 3-5 times over rates of Gobisumber aimags. No neuromuscular forms of neurohereditary diseases i.e spastic paraplegia (11.3%) and spinocerebeller ataxia (9.68%) accounts for 21% among all forms of neurohereditary diseases. The prevalence of neuromuscular diseases in the population of these six provinces is two times high then the average rate of the population of Russia (1980 years). First reason is may be associated with high predisposition of based on consanguineous through reproductive way in some of these provinces of Mongolia.

BackgroundEarly detection of minor strokes and their treatment that aim to prevent from complications into severe strokes is a process of secondary prevention. There is a need to extensively use image diagnostics (CT, MRI) because signs are obscure, at times without focal neurological sign but can have special mental or psychological syndromes. The start of minor stroke studies in Mongolia will enable further deepening of these studies in future and give an impetus to identification of theoreticaland practical aspects together with further improvement of diagnostics, treatment and prevention of minor strokes.GoalTo develop and introduce the diagnostic criteria of ischemic and hemorrhagic minor strokes in accordance to the concepts of minor strokes and to treat minor stokes in order to prevent complications into severe strokes.Materials and MethodCurrently there are no globally accepted diagnostic criteria for minor stroke. We support the 1981 WHO criteria of minor strokes as strokes neurological signs of which disappear in relatively short period of time. There is a general notion that it should mean all light forms of stroke other than severe strokes. In cases of neurological signs of a minor stroke, complete recovery and elimination of the symptoms take up to 3 weeks. Most scholars tend to consider ischemic lacunar strokes (arising from occlusion of arteriole vessels deep in the brain and with size of 0.5-20 mm) as minor strokes. We maintained the concept that characteristic features of these strokes are their limited focal areas and the following neurological symptoms: pure motor, pure sensory, light ataxia, etc. We also duly considered a suggestion (D. German, L. G. Koshchug et al, 2008 ) to define minor hemorrhagic strokes as strokes with diameter less than 2 cm and blood volume less than 5 cm3.We identified 60 patients with minor strokes, involved in monitoring using special research template (with a term of at least 1.5years) and involved in pathogenesis treatment. In the treatment, we maintained a principle of differential diagnosis of ischemic stroke symptoms. Specifically, we differentiated the following: signs related to an atherotromb, cardio-embolic, lacunar, hemodynamic, hemorheologic pathogenesis. To verify the diagnoses, we used MRT and CT image tests. We executed paraclinic tests in order to identify risk factors: Doppler-duplex-sonography, brain angiography, blood lipid fraction, ECG, EchoCG, heart Holter, blood hemorheology test, and identified the most affecting factors (hereditary factors, excess weight, smoking etc).Results: Our study identified the following clinical forms: lacunar stroke, non-lacunar minor stroke, and hemorrhagic minor stroke. Among the minor strokes, the lacunar stroke dominates (48%), the nonlacunar stroke is the next (27.7%), and the hemorrhagic was found to be the least common 25%. From among a host of risk factors, arterial hypertension is dominant (86%) either alone or in combination with such other diseases as diabetes, atherosclerosis etc. Diabetes occurrence was 5 cases (8,3%) which is fewer than in some foreign studies.The clinic of minor stroke also varies. The strength and expression of their symptoms compared with those of severe strokes are unique in the following:- Relatively lighter and recover faster as a result of treatment even in acute forms,- Some are without specific clinical signs (“silent stroke”).- Some minor strokes have micro focal signs, for example, “pure motor”, pure sensory, ataxia etc, in other words, the signs are limited.- In cases of lacunar strokes, predominantly deep brain arterioles are damaged.- Whereas in non-lacun strokes, embolic, ateroma, thrombotic mechanisms are predominant suchas distal branches of big artery. - In cases of hemorrhagic minor strokes, arteriopathy distortions occur not only in depth of brain but also in any small lobar vessels of brain.- Focal lesions have some variations by their pathological locations and minor stroke signs.In non-lacunar strokes (25%), the focal damages predominantly occur in branches of large intra/extra cranial arteries. In cases of lacunars strokes, the focal lesion is not in branches of large intracranial vessels, but is predominantly in basal ganglia, deep white matter, thalamus, pons and in area of deep penetrating arterial vessels. However, focal infarcts in cerebella may occur in any form of minor strokes.ConclusionAccording our study there were identified 3 subtypes of minor stroke. The finding is that lacunars and hemorrhagic minor strokes are more likely to give grounds to severe strokes. From this, it can be concluded that there are specific factors in the population of Mongolia to affect the genesis of minor strokes, namely, arterial hypertension which is directly related with these forms of minor strokes. We appropriate the WHO criteria of minor stroke that is neurological signs of a minor stroke, complete recovery and elimination of the symptoms take up to 3 weeks. In treatment of minor stroke, we suggest that minor strokes should be treating by pathogenetic therapy. Namely, antihypertensive therapy for lacunar infarction, anti-aggregation therapy for nonlacunar infarction and haemostatic and antihypertensive therapy for hemorrhagic minor stroke.

Background: Stroke is still one of the leading causes of morbidity and mortality worldwide. Registry-based data of stroke are scarce in low and middle-income countries such as Mongolia. We aimed to investigate the incidence and mortality of stroke in adult population of UB Mongolia by stroke registration method. Material and Method: Covering 611265 (≥15 years old) adult citizens of three districts of Ulaanbaatar, a population-based prospective study was done from the first, January of 2019 to 31st, December of 2019. All first-ever and recurrent stroke cases were included using special software, developed for stroke registry, based on the WHO STEPS approach from participating radiology departments of state hospitals, district hospitals, and family clinics. Information of stroke death was obtained from forensic institute and state registration office of the capital city. Results : In a 1-year study period, 1068 (women 39.1%) stroke cases were registered in people with 60.16±13.66 years old. Stroke incidence rate was 169.81/100000 including first-ever and recurrent events. Stroke incidence rate was higher in men and people with 80 and above years old. The ratio between IS and ICH was 1.14:1.0. Stroke mortality was 27.1% and mortality rate was 45.94/100000. The highest rate mortality was in ICH subtype, male population and older people. Conclusion We identified relatively high incidence and mortality rate of stroke in ICH indicating an urgent need for improvement of arterial hypertension control, health education and primary prevention mainly among men.

Background: Spinal muscular atrophy (SMA) is a degenerative neuromuscular disease that causes progressive muscle weakness and atrophy due to the loss of the motor neurons. Approximately 95% of patients with SMA are homozygous for the deletion of SMN1 exon 7. With an incidence of 1/10.000 and a carrier frequency of 1/40 to 1/50, SMA is the most common genetic cause of death in infants. Purpose: To detect homozygous deletion of SMN1 exon 7 and to analyse the SMN1 copy number by molecular genetic analysis. Materials and Methods: In this study, 3 SMA patients with SMN1 gene homozygous deletion and 17 people of their relatives were included. Molecular genetic analysis was performed in the Central Scientific Research Laboratory of the Institute of Medical Sciences. DNA was extracted from peripheral blood, and its purity was assessed by spectrophotometer. Homozygous deletion of SMN1 gene was analyzed with allele-specific PCR, and the SMN1 gene copy number was evaluated by real-time PCR. Results: Among the five participants diagnosed with SMA by clinical symptom and electromyographic test, three cases were found to have homozygous deletion of exon 7 of the SMN1 gene, while two cases did not exhibit such mutation by the allele specific PCR analysis.
The mean age of study participants was 27.76±16.07 (ranging from 8 months to 52 years). Six of the 7 relatives of the first proband had 1 copy number of SMN1 (0.75±0.29) or were carriers of SMA, while one had 3 copy numbers (2.99) or no deletion of SMN1 gene. Additionally, 6 of the 7 individuals of the second proband had 1 copy number of the SMN1 gene (0.72±0.14), and 1 person had 2 copy numbers. All 3 relatives of the third proband had 1 copy number of SMN1 gene (0.96±0.37). Conclusion We consider that determination of SMN1 gene homozygous deletion and carrier testing can be performed by the PCR method locally. Further, it is necessary to implement the molecular genetic testing method into practice and to study the requirements and needs of early detection of SMA in the newborn screening program of Mongolia.