Epidemiological and Clinical Study of Familial Epilepsy in Lubumbashi

Ntenga P^1*, Touré Kamadore², Ilunga Kabulo M³, Koba Bora B¹, Alain Kasongo³, Numbi Kilumba S¹, Bugeme M¹, Mukeng KD³, Mulumba A⁴, Omangelo Shongo F¹, Sedar Ceylaner⁵, Muyumba K¹, Monga Ben⁶, Ngoy Nkulu D¹

¹University of Lubumbashi, Faculty of Medicine, DRC
²Cheikh Anta Diop University, Dakar, Senegal
³Neurodiagnostic Center of Lubumbashi, Lubumbashi, DRC
⁴Dr. Joseph Guislain Neuropsychiatric Center of Lubumbashi, Lubumbashi, DRC
⁵Genetics and Rare Diseases, Diagnosis Center, Ankara, Turkey
⁶University of Lubumbashi, School of Public Health, DRC

*Correspondence author: Patrice Ntenga, University of Lubumbashi, Faculty of Medicine, DRC; Email: [email protected]

Citation: Ntenga P, et al. Epidemiological and Clinical Study of Familial Epilepsy in Lubumbashi. J Neuro Onco Res. 2025;5(3):1-14.

Copyright^© 2025 by Ntenga P, et al. All rights reserved. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Table 1: Mean age of patients.

It appears from this table that the patients had a mean age of 15.24pm11.03 years, with a median of 14 years, 7 years at the 1st quartile and 20 years at the 3rd quartile. The distribution of patients according to their sex is shown in the Fig. 2 below.

It emerges from this figure that the sex ratio is 1.32, in favor of men.

Table 2: Distribution of patients according to seizure types.

We observe from this table that generalized tonic-clonic seizures were the most common with 70.83% of cases, followed by absence seizures with 8.33% of cases. The frequency of other seizures ranged between 1.39% and 4.17% of cases. The EEG results in patients with a family history of epilepsy are shown in Fig. 3 below.

1. Distribution of patients according to EEG results

This Fig. 3, originally a bar chart, would illustrate the proportion of patients whose EEG was performed, normal or abnormal. Our results show that EEG was performed in the majority of patients (63.49% of cases) and was normal in 27.78% of cases and abnormal (presence of paroxysmal grapho-elements) in 35.71% of cases. The non-performance of this examination represented 38.57%.

Table 3: Distribution of patients according to the duration of consultations.

1. According to mode of transmission

In Fig. 6, we considered the autosomal dominant and autosomal recessive modes.  We deduce from this Fig. 6 that epilepsy is transmitted in the autosomal dominant mode in 41.67% of cases and in the autosomal recessive mode in 33.33% of cases.

Table 4: Distribution of patients according to sex and seizure type.

Reading this table shows us that generalized tonic-clonic seizures are present in considerable proportion in both sexes (64.5% of cases for females and 75.6% of cases for males) followed by absence seizures in males with 9.76% of cases, for a corrected chi-square of 6.1.

According to mode of transmission and seizure type (Table 5).

Table 5: Distribution of patients according to mode of transmission and seizure type.

It appears from this table that CGTC are transmitted in 70% of cases according to the autosomal dominant mode and in 62.5% of cases according to the autosomal recessive mode, while absence seizures are transmitted in 12.5% of cases according to the autosomal recessive mode, with a corrected chi-square of 11.46.

Discussion

Prevalence of Familial Epilepsies

Our study collected 72 families with a history of familial epilepsy, out of a total of 641 patients diagnosed with epilepsy during consultations, representing a prevalence of 11.23% of cases. This result is consistent with other authors, notably M Ndiaye, et al., in Senegal, who found a general frequency of familial epilepsies of 11% in their study. The same observation was made by Kuate-Tegueu Callixte in 2014 in Cameroon in his study on epilepsy, who found that more than half (57.1% of cases) of patients living with epilepsy had a family history of epilepsy and among these, 11.4% of cases had two family members suffering from epilepsy and in 10% of cases, some had three or more patients suffering from the same epileptic disease [39,40].

Notion of consanguinity While Lamine Thiam in Senegal in 2020, in his study on the clinical and paraclinical aspects of idiopathic epilepsy in children at the Hôpital de la Paix in Ziguinchor, showed that 18 children were followed for idiopathic epilepsy and that parental consanguinity and family history of epilepsy were found in 1 and 6 children respectively (i.e., 5.5% and 33.3% of cases). This leads us to say that the prevalence of 11.23% of cases in our environment without a notion of consanguinity, as shown in Fig. 7, between parents in our environment, pushes us to seek a hereditary character that needs to be demonstrated and to identify the genes and/or variants involved. This is why, for several years, the role of ion channels in epilepsy has been suspected, mainly on physiological arguments, because ion channels (Na+, K+) are responsible for the generation of action potentials, neurotransmitter receptors are themselves channels or are coupled to ion channels and many antiepileptic molecules act directly or indirectly on their functioning. Recent molecular genetics data have confirmed this role. Indeed, the study of familial forms of epilepsy has made it possible to incriminate genes that code for subunits of ion channels or subunits of channel receptors [41,42].

In their studies on epilepsy, a family history of epilepsy was found 2 to 3 times more often in patients with epilepsy than in controls [43,44]. It has been shown in the literature that consanguineous marriages are common in certain cultures in Asia, particularly in Indian or Muslim communities. In a study in India, consanguineous parents were more frequent among patients than among controls (13.1% vs. 6.6%) (2.6; 95% CI: 1.5-4.4) [45]. The association with consanguinity is stronger in generalized epilepsies than in localized epilepsies and in idiopathic or cryptogenic epilepsies than in symptomatic epilepsies [46,47].

Average age and sex as shown in Table 1 and Fig. 2, in our cohort, the average age at diagnosis of patients living with epilepsy is 15.24pm 11.03 years. With a maximum of 75% at 20 years and a mode of 17 years. For her part, Zubcevic, 2009, reported an average age at diagnosis of 5 years. Many other studies report a high frequency of hereditary seizures in children [48].

In their studies, Dadah Samy Mohamed Lemine, et al., and Mukuku O, et al., reported an average age of patients living with epilepsy in Senegal that ranged around 8 years, with a peak found in the 5 to 10 year age group. Also, male predominance as we demonstrated in our study with a sex ratio of 1.32 [48-50]. This male predominance found is explained by the possible neurobiological difference between the neurons of male and female subjects leading to a differentiation of responses during brain lesions [51]. This male overrepresentation could also be explained in our environments by an underreporting of the disease in young women of marriageable age. For their part, Amina Chentouf, et al., in Algeria found in their study on the clinical characteristics and hereditary profiles of epilepsies a sex-ratio of 1.35 in favor of the male sex without a notion of X-linked transmission [52].

Therapeutic itinerary, drug treatment, time between onset of disease and day of consultation. The results recorded in Fig. 4 of our study showed that in 48.61% of cases, patients followed a drug treatment before arriving at the hospital and that traditional treatment and prayer accounted for a significant proportion, namely 36.11% and 9.72% of cases. Furthermore, in the quest for healing, patients find themselves in conditions where they combine several treatment methods. The cumulative percentage of patients who followed the path of prayer and traditional treatment sufficiently shows the significant proportion of presenting for consultation beyond 12 months, as shown in Table 5 of this study.

Moreover, this disease is associated with several false beliefs that lead to stigmatization that the evolution of scientific knowledge cannot change in Africa. Thus, we believe that many people with epilepsy live hidden in the shadows due to the social burden, which greatly impacts many studies because only a minority will come to the hospital for treatment. Furthermore, it is known that beliefs, perceptions and apprehensions vary from one country to another and can in all cases influence individual and collective strategies regarding treatment options [53].

At the medical level, the treatment of epilepsy faces various obstacles, whether it is the cultural perception of the disease, the low priority given to it by health authorities, infrastructure deficiencies or the irregularity of drug supply. Therefore, we believe that the high cost of medicines, the lack of social coverage, distance, the unequal distribution of health structures, all these situations associated with the lack of qualified personnel make the situation of people with epilepsy difficult, as other authors have pointed out [48].

Epilepsy, as a chronic disease that requires long-term care, seems unusual in Africa or even poorly accepted and therefore, the social impact of the disease in Africa, the social and cultural consequences of the disease are extremely detrimental to epileptic patients. They can be broadly summarized in one word: rejection or stigma. Rejection also comes from the family circle, although patients are almost never driven out of their homes and rarely sleep in a separate place (“disease from behind the house”). It is not real exclusion but rather marginalization. The patient is never banned, regardless of the society studied. They are tolerated, but no longer have a role in society (Andriantsimahavandy A, 1997). Patients suffer from this marginalization. They are ashamed of their illness, often feel diminished and therefore hide the diagnosis from others. The epileptic in Africa is a deviant whose existence is tolerated. They are a model of collective anxiety and social surveillance. Because of its frequency and heavy socio-economic consequences, epilepsy in developing countries like the Democratic Republic of Congo still represents a major public health problem [47]. Therefore, a community approach and widespread public awareness will be needed to effectively manage the problem of epilepsy. From the analysis of Fig. 5, it appears that clinicians primarily resorted to monotherapy (65.27%) in the induction of epilepsy treatment, while the use of bitherapy and tritherapy represented only 11% in total, 9.72% in the first case and 1.39% in the second. The induction of anticonvulsant treatment by monotherapy was also found by other authors, notably M Ndiaye, et al., and M Bourrous, et al., who, in their respective studies, found that monotherapy was the most used therapeutic regimen and that valproic acid was the most commonly used molecule [44,45].

The data from our study show that a significant proportion of patients living with epilepsy, namely 23.61% of cases, did not receive treatment, certainly for multiple reasons that could also find some explanations as mentioned in Fig. 4 and therefore, the reasons for this therapeutic insufficiency in sub-Saharan Africa seem complex and multifactorial. They involve socio-cultural, economic causes and even the inaccessibility and inadequacy of health structures. It is therefore important, in our opinion, to continue research in this area as part of the fight against epilepsy. As early as 1994, Danesi MA, et al., in their survey on epilepsy and population attitudes, showed that in 57% of cases, patients admitted to first resorting to traditional medicine. Moreover, to justify this attitude, in addition to beliefs, 43% of those surveyed cited the high cost of anti-epileptic drugs. Indeed, all socio-cultural factors and especially the supposed (supernatural) causes of epilepsy, can explain the recourse to traditional therapists and/or the combination of several treatment modalities in the quest for a solution. Dale JR, on the other hand, in 1984, in his study conducted among Tanzanian traditional practitioners, showed that they often took care of patients living with epilepsy, while epilepsy was not listed as a health problem in the modern health care system. Therefore, it is normal to understand here the difficulty of conducting a good study on the prevalence and/or incidence of epilepsy in many areas, because generally, it is the first recourse (traditional medicine and/or prayer) and only the observation of several failures could motivate a hospital consultation.

Type of Seizures

We found that generalized tonic-clonic seizures were the most common with 70.83% of cases, followed by absence seizures with 8.33% of cases. The frequency of other seizures ranged between 1.39% and 4.17% of cases. In his study on epilepsy and schooling in Congolese epileptic children, Ntenga Parice found that generalized tonic-clonic seizures were the most common with 41.7% and a p-value of 0.04, followed by absence seizures with 33.3% and a p-value of 0.67. This strong representativeness of generalized tonic-clonic seizures would be justified by their spectacular nature and thus easy recognizability, but also by the population’s lack of knowledge of other types of seizures. This same observation has been made in most studies conducted in Africa (Dadah Samy Mohamed Lemine (Senegal, 2015), Chentouf A [39].

Mode of Transmission of the Pathology According to the Pedigree

We noticed from Fig. 6 that the autosomal dominant mode of transmission represents 41.67% of cases and that transmission according to the autosomal recessive mode is around 33.33% of cases. This result contradicts that of MEFOUNG Ephrata Samuel, 2021, for whom the autosomal recessive mode of transmission represented more than half of the cases. On the other hand, our results are comparable to those of a study conducted in Algeria by Chentouf A, et al., who found a high prevalence in favor of the autosomal dominant mode. And so, this leads us to say that these differences could be justified by the sample sizes which are different to characterize a national distribution and highlight the predominance of one mode of transmission over the other [40].

Conclusion

We conducted a prospective, cross-sectional analytical study from October 2020 to October 2024, which included epilepsy cases presenting for consultation during the study period. Patients aged 40 years or younger with epilepsy and their families who were seen at the aforementioned investigation sites, with a notion of familial epilepsy discovered or reported during the consultation, were considered as potential candidates for this study. We performed a stratified probabilistic sampling during this study to select the subjects who participated. A total of 72 families were collected and subjected to statistical analyses. This allowed us to demonstrate that:

• The prevalence of familial epilepsy in Lubumbashi is 11.23% of cases.
• The mean age of patients with epilepsy and a family history of the disease is 15.24 ± 11.03 years, with a median of 14 years, a 1st quartile of 7 years and a 3rd quartile of 20 years.
• The sex ratio is 1.32, favoring males.
• Generalized tonic-clonic seizures came in first place, with 70.83% of cases, followed by absence seizures with 8.33% of cases. The frequency of other seizure types ranged from 1.39% to 4.17% of cases.
• The EEG was performed in the majority of patients (63.49% of cases) and was normal in 27.78% of cases and abnormal (presence of paroxysmal grapho-elements) in 35.71% of cases. The exam was not performed in 38.57%.
• In 48.61% of cases, patients were on medication before arriving at the hospital and traditional treatment (36.11%) and prayer (9.72%) accounted for a total proportion of 45.83%.
• Clinicians primarily resort to monotherapy (65.27%) to initiate treatment for epilepsy, while the use of dual and triple therapy accounted for only 9.72% and 1.39% of the total, respectively. Furthermore, for various reasons, some patients had not received any treatment (23.6%).
• In 73.61% of cases, patients and/or their families were only able to come to the hospital more than one year after the onset of the disease. The remaining 26.4% represented a duration of less than 6 months and a duration ranging between 7 and 12 months.
• Epilepsy is transmitted in an autosomal dominant and recessive manner in 41.67% and 33.33% of cases, respectively.
• No patient came from a consanguineous marriage.

Perspectives

The analysis of this epidemio-clinical data on familial epilepsy in Lubumbashi is essential and impacts understanding. These data should be the subject of further investigation with a genetic study to understand the specifics.

Conflict of Interest

The investigators declare no material or financial conflict of interest related to this study.

Funding

No source of funding for this study.

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