Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders affecting a child’s communication, interpersonal relationships, behaviors, and activities that are restricted and repetitive [1] [2] .

ASDs are present from birth, but symptoms usually appear in early childhood [1] [3] . Although specific management can lead to notable improvements in performance, ASDs remain present throughout life [4] [5] .

Worldwide, the most recent studies estimate that the prevalence of ASD varies between 90 and 120 individuals per 10,000 inhabitants, or approximately 1% of the general population, in children as in adults [6] [7] . Other more recent studies have reported an even higher prevalence of 157 to 260 per 10,000 inhabitants in the United Kingdom and South Korea [7] [8] . In the United States, in 2014, the prevalence of ASD was estimated at 168 per 10,000 children aged 8 years [9] .

In Africa, a few studies have been conducted specifically on ASD. Their estimated hospital frequency is between 2.3% and 7.8% [10] [11] .

ASDs have significant repercussions on the lives of children and their families [5] . They have a considerable impact on both learning and social integration [2] .

The management of ASD is multidisciplinary. It is based on intensive behavioral and educational interventions [12] - [14] . It must be early in order to promote a better prognosis in terms of social integration and disability, thanks to cerebral neuroplasticity [5] .

In Congo, little data exists on autism spectrum disorders and their associated factors. This raises the issue of ASD management in Congo. Hence, the objective of this study is to identify the factors associated with the development of ASD in the neurocognitive exploration unit of the Brazzaville University Hospital in Congo.

This was a prospective cohort study conducted from January 1, 2021, to September 30, 2022, a period of 21 months, carried out in the neurology department of the University Hospital Center of Brazzaville (CHU-B) specializing in the management of neurological conditions in children and adults in the department of Brazzaville.

This service includes four sub-units, namely:

Subject recruitment was carried out exhaustively over the entire study period.

The study included patients:

The following patients were not included in our study:

The study variables were:

The treatment protocol, codified and adapted based on ASD symptoms and associated comorbidities, involved several stakeholders, including a neurobehavioral therapist, a speech therapist, a psychologist, special educators, a psychomotor therapist, a neurologist, and a psychiatrist.

Depending on the severity of the ASD, an educational and pedagogical approach was provided by specialized educators in the special school for the severe form and in the mainstream school for the mild and moderate forms. Each patient received schooling for 9 months.

For verbal and nonverbal communication disorders, speech therapy was provided with 2 to 3 speech therapy sessions lasting 45 minutes or even 1 hour per week. It consisted of working on and/or strengthening communication prerequisites (through pointing, imitation, and the logical arrangement of objects and photos) and oral language (through sentence construction using pictures and pictograms, as well as naming and reading text). It also involved implementing alternative and augmentative communication using the Picture Communication Workbook (PECS).

For behavioral and social interaction disorders, neurobehavioral and developmental care was provided using behavioral and developmental approaches at a frequency of two sessions per week for a duration of 45 minutes to one hour, in the schools where each patient was located. This care was provided by psychologists, speech therapists, and special educators under the supervision of the neurobehavioral therapist. Behavioral approaches aimed to reduce the maladaptive behaviors of patients with ASD by integrating the learning of new behaviors to facilitate autonomy and social integration through play-based activities and time tracking. This time tracking was achieved using a visual schedule with pictograms moving throughout the day.

Developmental approaches are aimed at motivating patients with ASD to interact with those around them with the aim of developing social communication. They were based on play, activities focused on imitation, looking and paying attention to an object, touching and pointing at objects, and sensory integration. These approaches were continued at home by parents who played with the children.

For those with fine and gross motor disorders, psychomotor therapy was provided. This consisted of relaxation, laterality, self-image, and muscle strengthening exercises, with a frequency of 2 to 3 sessions per week. Speech therapy and neurobehavioral therapy were combined with other forms of care in cases of comorbidities.

Thus, for patients with learning disabilities and intellectual disabilities, psychological support was provided for 1 hour at a frequency of 2 to 3 sessions per week. This consisted of cognitive behavioral therapy (CBT) using cognitive exercises that positively modify the patient’s negative beliefs and thoughts about themselves.

For those with sleep disorders, treatment was provided by a neurologist with the introduction of weight-based, low-dose melatonin, combined with appropriate sleep hygiene.

However, for patients with epilepsy, antiepileptics such as sodium valproate and valpromide were prescribed weight-based, low-dose medications for an initial period of 1 month, then renewed after a reassessment. Those with psychiatric disorders such as ADHD, depression, aggression and self-harm had appropriate psychiatric care: psychostimulants (methylphenidate) were prescribed for ADHD, antipsychotics (risperidone) for aggression and self-harm and antidepressants (fluoxetine) for depression.

Data were entered and processed using Excel software and statistical analysis using SPSS version 23.0 software. Quantitative variables were presented as mean and standard deviation and qualitative variables expressed as frequency. To identify factors associated with the evolution after 9 months of follow-up, a univariate analysis was performed; that is, the variable of interest (level of severity) was crossed with the explanatory variables (sociodemographic, clinical and therapeutic). Pearson’s chi-square test was used to compare the numbers. When the theoretical number was less than 5, the Fisher Exact test was used. The significance threshold was set at 5%.

An improvement in the severity of ASD was noted in the present study with an improvement rate of 10.9% from the initial assessment to the final assessment carried out 9 months after treatment. There is increasing evidence that treatment of ASD is associated with an improvement in their severity [15] - [17] . This observation highlights the interest in creating centers dedicated specifically to the treatment of ASD.

This improvement is explained by the management of ASD in the present study, which was codified and adapted to the symptoms presented by the patients as well as to the associated comorbidities. This management was established on the basis of international recommendations [18] . In our study, the management consisted of educational support and integration into ordinary schools for mild and moderate forms and into special schools for severe forms. It also consisted, in the majority of cases, of speech therapy and psychotherapy. To a lesser extent, psychomotor rehabilitation was implemented. Developmental and behavioral therapies, more specific to ASD, were introduced in half of the cases. In some patients, specialized medical care was necessary.

The low control rate at 9 months could be explained by the lack of effective improvement in absent patients.

Several factors influenced this improvement. These were the age group of less than 6 to 10 years at the time of diagnosis, the absence of intellectual disability, learning disabilities and integration into a regular school.

Various studies regarding integration into mainstream schools show that even with a disability, similar progress can be observed both in mainstream schools and in specialised settings [19] [20] . Rose et al. [21] indicated that children with language disorders in mainstream schools engage more in collaborative play, have more positive social interactions and engage less in solitary play. Implementing national programs and creating specialized centers dedicated to the care of ASD will ensure better awareness and education of populations and facilitate the social reintegration of patients with ASD.

Besides school integration, factors involved in the improvement of ASD are early treatment, young age, and the absence of cognitive disorders. It is important to emphasize that the degree of severity of the majority of patients with ASD in the present study was moderate. Patients who presented severe forms had the lowest rate of improvement, i.e., 4.3%. They were older, presented with cognitive disorders, and were enrolled in a special school. Western studies report that the intellectual disability associated with ASD is undoubtedly a factor in the aggravation of the intensity of the symptomatology, and the evolution is significantly better than in forms without intellectual disability [22] [23] . It is important to raise awareness among parents of children with ASD about the benefits of early care and regular monitoring in improving the quality of life of children with ASD in order to facilitate their socio-relational integration.

In Congo, ASD is frequently associated with intellectual disability, learning disabilities, and eating disorders. After codified and adapted care, a significant improvement in the severity of ASD is observed. Factors associated with this improvement are young age at diagnosis, the absence of cognitive disorders, and schooling in a regular school. The need for awareness campaigns is crucial for the early detection of behavioral and communication disorders. Additionally, implementing a neurocognitive assessment for students upon school admission, whether in regular or special education, is necessary.