Functional neurological disorders (FNDs) are commonly encountered in practice; however, there is a paucity of data in Africa.
To identify and describe the clinical profile of patients presenting with FNDs, underlying medical and psychiatric diagnoses and review the investigation and management of these patients.
Inkosi Albert Luthuli Central Hospital (IALCH), a tertiary-level hospital in Durban, South Africa.
A retrospective chart review and descriptive analysis were performed over a 14-year period (2003–2017) on cases meeting the study criteria.
Of 158 subjects, the majority were female (72.8%), had a mean age of 32.8 years, were single (63.3%), unemployed (56.3%) and of black African ethnicity (64.6%). The most common clinical presentation was sensory impairment (57%) followed by weakness (53.2%) and seizures (38.6%). Inconsistency was the most frequent examination finding (16.5%). Medical conditions were identified in half of the study population (51.3%), with hypertension (22.2%) and human immunodeficiency virus (HIV) (17.2%) being most common. Of patients with a psychiatric diagnosis (55.1%), 25.3% had depression. Magnetic resonance imaging (MRI) was the most frequently performed investigation (36.1%). The majority of patients received psychotherapy (72%) and most had not shown improvement (55.3%) at a median follow-up of 2 months, whilst 17% had deteriorated.
Functional neurological disorders were most frequently diagnosed in young unmarried females, of black African ethnicity. Family history, personal exposure to a neurological illness and certain socioeconomic factors may be potential risk factors. Sensory impairment was the most common clinical phenotype. Further studies are needed to better understand and manage FNDs in the South African context.
Functional neurological disorders (FNDs) refer to the presence of neurological symptoms in the absence of organic neurological disease and have been documented for centuries under such terms as ‘hysteria’.
Charcot used the term ‘functional’ to describe those disorders where no anatomical or histological pathology could be demonstrated but function was impaired.
Terminology has included purely symptomatic diagnoses or syndromes, ‘non-diagnoses’ such as ‘non-epileptic seizures’ and psychogenic, psychosomatic or functional disorders. Psychiatric terms include conversion disorder, somatisation, dissociative motor disorder, hypochondriasis, factitious disorder, Munchausen syndrome and malingering. All carry different connotations with regard to causation and may affect the patient’s perception of their illness.
‘Functional neurological symptom disorder’ was added to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) criteria in 2013 and distinguished functional disorders from intentional disorders such as malingering or factitious disorder, although this distinction is debated.
‘Functional neurological symptom disorder’ is a broad term implying a change in function rather than structure and has become a preferred term, as it avoids the insinuation that ‘everything is in the patient’s mind’ and uncertainty as to whether the problem is neurological or psychological.
Functional neurological disorders are commonly encountered in neurology clinics and may cause levels of disability and impaired quality of life similar to multiple sclerosis and Parkinson’s disease.
One-third of neurological outpatients experience symptoms regarded as ‘not at all’ or ‘only somewhat’ explained by disease,
Neurologists and non-neurologists alike are often faced with the challenge of inconsistent examination findings, uncertainty as to whether there is co-existent organic pathology and the need to investigate these patients, sometimes at unnecessary cost. In resource-limited settings with high burdens of disease such as South Africa, the need to practise evidence-based, cost-effective medicine is essential.
Although a number of international studies have described the spectrum of FNDs, there is a paucity of data from South Africa and recent literature from Africa. Studies that describe the spectrum of FNDs were either conducted over 50 years ago or if more recent have focussed primarily on psychogenic non-epileptic seizures (PNES) and included relatively small sample sizes.
The aim of this study was to document the experience at a tertiary-level referral centre in Durban, South Africa, and identify the clinical profile, investigation and management of patients with FND presenting to the Inkosi Albert Luthuli Central Hospital (IALCH) over a 14-year period. Inkosi Albert Luthuli Central Hospital serves a population of approximately 18 million people. Patients attending public health facilities in Kwazulu-Natal (KZN) (approximately 79.5% of the population) are mostly of black African ethnicity (90.3%) reflecting local demographics.
Addressing the relative lack of local data on this subject may lay the foundation for future research in this important yet neglected field in Southern Africa.
A retrospective chart review was conducted on patients presenting to IALCH with a diagnosis of FND between 2003 and 2017. The tenth revision of the International Statistical Classification of Diseases and Related Health Problems (ICD) coding system was used to identify cases. ICD codes F44 – dissociative (conversion disorders), F45 – somatoform disorders, F51 – non-organic sleep disorders and F99 – mental and behavioural disorders were included. Data were extracted by using the Clickview software program, a data extraction program that is able to select patient charts via specific patient numbers according to ICD-10 codes entered. Charts were accessed via the Meditech software system. Patients with an organic neurological disease that may have explained their symptoms and those with insufficient clinical information were excluded. A total of 158 patients were analysed.
A data collection tool created by the authors was used to document demographic data, clinical presentation, examination findings, organic disease, psychiatric illness if known or diagnosed during admission, investigations performed, management and follow-up.
Descriptive analysis was used to address all the objectives. Continuous variables were summarised by using mean, standard deviation and range, whilst categorical variables were tabulated as frequency and percentage. Categorical variables were analysed by using the Chi-square test, and non-parametric testing was performed for continuous variables. IBM SPSS version 25 was used to analyse the data.
The Ethics committee of the Faculty of Health Sciences at the University of Kwazulu-Natal, Durban, South Africa, granted the ethical approval for the study, reference number: BE042/18.
During the 14-year study period, 158 subjects with FND were analysed. Patient demographics and characteristics are listed in
Patient demographics and clinical characteristics.
Variable | Frequency, total 158 |
|||
---|---|---|---|---|
Mean | s.d. | % | ||
Female | - | - | 115 | 72.8 |
Male | - | - | 43 | 27.2 |
Black people | - | - | 102 | 64.6 |
Indian | - | - | 41 | 25.9 |
White people | - | - | 12 | 7.6 |
Not captured | - | - | 3 | 1.9 |
Unemployed | - | - | 89 | 56.3 |
Employed | - | - | 58 | 36.7 |
Not captured | - | - | 11 | 7.0 |
Single | - | - | 100 | 63.3 |
Married | - | - | 46 | 29.1 |
Partner | - | - | 4 | 2.5 |
Not captured | - | - | 8 | 5.1 |
Christian | - | - | 9 | 5.7 |
Muslim | - | - | 4 | 2.5 |
Hindu | - | - | 3 | 1.9 |
Not captured | - | - | 141 | 89.2 |
Hypertension | - | - | 18 | 22.2 |
HIV | - | - | 14 | 17.2 |
Asthma | - | - | 13 | 16.0 |
Diabetes mellitus | - | - | 7 | 8.6 |
Not captured |
- | - | 29 | 35.8 |
s.d., standard deviation.
, Only the four most common organic conditions were analysed.
Sensory disturbance,
Neurological presentations of functional neurological disorders.
Phenotype | Frequency, total 158 |
|
---|---|---|
% | ||
Hemisensory loss | 32 | 35.60 |
Level | 12 | 13.30 |
Dermatomal | 1 | 1.11 |
Other |
8 | 8.90 |
Not captured | 37 | 41.00 |
Paraparesis | 31 | 36.90 |
Hemiparesis | 28 | 33.30 |
Monoparesis | 11 | 13.10 |
Quadriparesis | 9 | 10.70 |
Triparesis | 1 | 1.20 |
Not captured | 4 | 4.80 |
Generalised | 33 | 54.00 |
Focal | 22 | 36.00 |
Not captured | 6 | 9.8 0 |
Tremor | 18 | 82.00 |
Other |
4 | 18.00 |
, Paraesthesias, facial numbness and hyperalgesia.
, Athetoid movements of upper and lower limbs (
Hemisensory loss was found in a third of subjects,
Eighty-four (53.2%) patients of the total study population complained of weakness. Paraparesis accounted for
There were 61 patients in whom a diagnosis of psychogenic non-epileptic seizures was documented. Generalised seizures,
A family history of seizures was present in 19.7% (
Other presenting complaints or in addition to the above are listed in
Other presenting complaints.
Complaint | Frequency, total 158 |
|
---|---|---|
% | ||
Headache | 19 | 12.00 |
Visual loss | 11 | 7.00 |
Gastrointestinal symptoms | 8 | 5.10 |
Neck pain | 8 | 5.10 |
Body/limb pain | 8 | 5.10 |
Lower back pain | 7 | 4.40 |
Dizziness | 7 | 4.40 |
Diplopia | 6 | 3.80 |
Mutism | 5 | 3.16 |
Memory loss | 5 | 3.16 |
Vertigo | 3 | 1.90 |
Jaw pain | 3 | 1.90 |
Facial pain | 3 | 1.90 |
Dysphasia | 2 | 1.27 |
Cramps | 2 | 1.27 |
Hypersomnolence | 2 | 1.27 |
Insomnia | 2 | 1.27 |
Dysarthria | 1 | 0.63 |
Syncope | 1 | 0.63 |
Falls | 1 | 0.63 |
Imbalance | 1 | 0.63 |
Eye pain | 1 | 0.63 |
Chest pain | 1 | 0.63 |
Tight chest | 1 | 0.63 |
Menorrhagia | 1 | 0.63 |
Not captured | 49 | 31.00 |
Inconsistency was the commonest clinical finding supportive of FND,
Clinical signs suggestive of functional neurological disorders.
Sign | Frequency, total 158 |
|
---|---|---|
% | ||
Inconsistency | 26 | 16.5 |
Intermittency | 25 | 15.8 |
Variability | 21 | 13.3 |
Hoover’s sign | 9 | 5.7 |
Distractible | 9 | 5.7 |
No ‘positive functional sign’ documented | 68 | 43.0 |
A psychiatric diagnosis was present in 55% of patients (
Psychiatric diagnoses in patients with functional neurological disorders.
Diagnosis | Frequency; total 87 |
|
---|---|---|
% | ||
Depression | 22 | 25.3 |
Depression and anxiety | 5 | 5.7 |
Anxiety | 1 | 1.1 |
Other psychiatric diagnoses |
19 | 22.0 |
Not captured | 40 | 46.0 |
, Somatisation disorder, post-traumatic stress disorder, psychosis, dysthymic disorder, panic attacks, histrionic personality disorder and narcissistic personality disorder.
Incontinence in association with forms of weakness.
Form of weakness | Total ( |
Frequency of incontinence |
|
---|---|---|---|
% | |||
Quadriparesis | 9 | 3 | 33.3 |
Hemiparesis | 27 | 4 | 14.8 |
Paraparesis | 31 | 4 | 13.0 |
Monoparesis | 11 | 1 | 9.1 |
Triparesis | 0 | 0 | 0.0 |
Data were insufficient to comment on how diagnoses were made before admission; however, when admitted, either the in-hospital psychologist or the attending neurologist made the diagnosis. Psychiatric symptoms reported included suicidal ideation, hallucinations, excessive agitation and feelings of dissociation such as ‘floating’ or ‘not being in control of a limb shaking’.
Family history, when documented, included several co-morbidities in family members: epilepsy (
Positive family history.
Condition known in family member | Frequency, total 35 |
|
---|---|---|
% | ||
Epilepsy | 18 | 51.0 |
Asthma | 5 | 14.3 |
Stroke | 4 | 11.4 |
Hypertension | 2 | 5.7 |
Multiple sclerosis | 1 | 2.9 |
Brain tumour | 1 | 2.9 |
Spinal pathology not specified | 1 | 2.9 |
Depression | 1 | 2.9 |
Visual loss | 1 | 2.9 |
Hearing loss | 1 | 2.9 |
Note: Patients with relatives who were asthmatic were all polysymptomatic:
Patient 1 presented with paraparesis and transient visual loss; patient 2 with seizures, sensory deficits, tightness of chest and abdominal pain; patient 3 with hemiparesis, headache, backache, dysphagia, dysphasia and imbalance; and patient 4 with paraparesis and syncope.
Stressors documented included domestic (
Psychosocial factors.
Psychosocial factor/stressor | Frequency, total 17 |
|
---|---|---|
% | ||
Domestic abuse ± stressors | 4 | 24.0 |
Motor vehicle accident | 3 | 17.6 |
Bereavement | 2 | 11.8 |
Work-related stressors | 1 | 5.9 |
Sexual orientation | 1 | 5.9 |
Rape | 1 | 5.9 |
Alcohol abuse | 1 | 5.9 |
Incarceration | 1 | 5.9 |
School failure | 1 | 5.9 |
Surgery | 1 | 5.9 |
Snakebite | 1 | 5.9 |
Investigations performed included magnetic resonance imaging (MRI),
Electroencephalographic findings were abnormal in three patients, of which two did not correlate with the patient’s clinical seizure semiology. The other showed an epileptic seizure captured in association with multiple non-epileptic seizures.
Investigations performed.
Investigation | Frequency, total 238 |
|
---|---|---|
% | ||
MRI | 86 | 36.1 |
CTB | 68 | 29.0 |
EEG | 57 | 24.0 |
LP | 27 | 11.3 |
MRI, agnetic resonance imaging; CTB, computed tomography scan of the brain; EEG, electroencephalography; LP, lumber puncture.
, Subjects may have had more than one investigation; therefore, total number investigations performed = 238.
Cerebrospinal fluid (CSF) results were abnormal in
The majority of patients,
Management.
Intervention | Frequency, total 184 |
|
---|---|---|
% | ||
Psychotherapy | 132 | 72.0 |
Antidepressants | 32 | 17.4 |
Physiotherapy | 20 | 10.9 |
, Patients may have received more than one intervention; therefore, the total is 184.
Less than one-third of patients,
Follow-up.
Outcome | Frequency, total 47 |
|
---|---|---|
% | ||
Static at follow-up | 26 | 55.3 |
Better at follow-up | 16 | 34.0 |
Worse at follow-up | 8 | 17.0 |
, Only 47 of 158 patients were followed up.
The present study described the spectrum of FND seen at a tertiary-level hospital in Durban, South Africa. This study documented the commonest clinical presentation of FND in a South African setting, demographics of patients presenting with these disorders, and provided insight into factors that may play a role in the development of the disease. It also demonstrated the lack of adequate management and follow-up of patients with FND and the need for improving patient outcomes (
This retrospective study of the spectrum of FND is, to the best of the authors’ knowledge, the largest systematic analysis of FND in Africa to date. Dekker et al.
In keeping with international studies and other African studies, a female predominance was noted.
Jacob et al.
As suggested in our study, social circumstances contribute to the development of FNDs and their role is thought to be causative in many cases.
A South African study of pseudoseizures in patients with neurocysticercosis found 17/29 (58%) female patients had experienced sexual or physical abuse and problems related to alcoholism and other socio-economic problems.
Gender-based violence (GBV) in South Africa is amongst the highest in the world.
Older studies in Africa have documented the influence of cultural beliefs on mental health presentations.
A high rate of psychiatric comorbidities including depression, anxiety, post-traumatic stress and personality disorders have been documented locally and internationally in patients presenting with PNES.
Our study also examined the overlap with organic disease, with hypertension being most commonly followed by HIV, asthma and diabetes mellitus; however, no significant correlations were found. Given the high prevalence of HIV in Southern Africa, this may reflect an under-recognised aspect of the neuro-psychiatric consequences of the HIV epidemic in sub-Saharan Africa. It is possible that the stress of being diagnosed with HIV or HIV-related neurocognitive impairment may contribute to the development of FNDs, but an incidental correlation between the two is also likely because of the high burden of HIV in South Africa.
In the 2018 Tanzanian case series and 1-year long retrospective review in the United States, the most common FND phenotypes reported were PNES and gait impairment, respectively.
We identified a predominance of paraparesis when patients were weak, hemisensory loss when patients had sensory symptoms and tremor when patients had a movement disorder. Tremor, being one of the most common forms of functional movement disorder, has been documented previously.
Previous reviews have reported a predilection for the left in up to 60% of patients presenting with functional weakness and sensory symptoms.
Multiple somatic symptoms such as headache, pain and fatigue are found in patients with FND. Irritable bowel syndrome (IBS), chronic fatigue syndrome, fibromyalgia and chronic pain syndromes are also documented.
The impact of family members’ illnesses on phenotypic presentations of FND, or ‘modelling’ as described by Stone et al.,
To distinguish FNDs from organic pathology, ‘positive functional signs’ may be found on examination. Some of these signs include inconsistency, intermittency, variability, Hoover’s sign, distractibility and the ‘hemisensory syndrome’. The commonest signs found in FNDs have not been documented locally. Inconsistency, the most frequently documented sign in our study, refers to discrepancies in findings but does not differentiate whether this is conscious or unconscious.
A number of considerations arise when investigating functional disorders. Investigations are performed to exclude organic pathology but some studies propose neuroimaging to support the diagnosis of FND. This includes the emerging theory of a ‘software problem’, which describes abnormal neurobiological mechanisms (‘software’) despite an intact macroscopic brain structure (‘hardware’).
In resource-limited settings, however, the exclusion of organic pathology overrides proving a pathophysiological basis of FND. For example, the 2018 study in northern Tanzania had access to a single CT scanner and EEG machine with the closest MRI facility being approximately 80 km away.
In an audit conducted in the United Kingdom by Parry et al.,
Cerebrospinal fluid analysis was the least frequently performed investigation analysed in our study and did not aid in diagnosis. Besides the attendant cost, LPs are invasive tests with procedural complications, and in patients with underlying psychiatric illnesses they may precipitate further somatic symptoms. This is another reason, besides cost, why limiting unnecessary investigations in patients with FNDs is crucial.
Neurophysiological studies other than the EEG, such as motor-evoked potentials (MEPs) and Bereitschaft potentials, may assist in further defining pathophysiology in FNDs.
Management of FNDs remains challenging, as demonstrated by the high proportion of subjects in our study who showed little or no improvement on follow-up. Whilst data on optimal management strategies are limited, there is evidence that a multidisciplinary team (MDT) approach is effective. This was shown in studies of inpatients with severe and chronic FNDs.
The benefit of rehabilitative physiotherapy, demonstrated in a randomised control study,
The majority of subjects were referred for or received psychotherapy (72%) and a smaller proportion were commenced on antidepressants (17.4%). This represents a higher proportion of patients with FND referred to psychiatric services than in a United Kingdom audit.
Psychotherapy, in particular, cognitive behavioural therapy (CBT) has shown benefit in the management of PNES compared with standard medical care.
Access to psychological support services may vary between the private and public sectors in South Africa. Patients attending an epilepsy-monitoring unit at a private hospital facility were noted to have access to an FDN integrating the work of psychologists, psychiatrists and neurologists,
Emerging data on the links between emotional states and FNDs have implicated autonomic dysregulation, abnormal limbic motor interactions and abnormal bodily awareness.
Therapeutic sedation has been used with some benefit in a case series although it remains a contentious form of treatment raising ethical concerns.
Newer treatment modalities such as transcutaneous electrical nerve stimulation (TENS) and transmagnetic stimulation (TMS) have not been described in the present study or other local studies, and whether such data from the developed world can be extrapolated to the South African context remains unknown.
The prognosis of patients with FNDs on long-term follow-up appears to be guarded. We found that of the subjects who were followed up in our study, the majority had no improvement in their symptoms and 17% reported deterioration at follow-up. This is in keeping with international data on the outcomes of functional motor disorders and PNES; however, these studies were limited by a lack of validated outcome measures.
A recent review by Pick et al.
Interest in the complex field of FNDs in South Africa is growing, and as more data on this subject becomes available, current practice will continue to evolve. Lack of training in the identification and management of patients with FNDs is noted to be a barrier to patient care; therefore, raising awareness amongst clinicians is an area of particular concern.
Although there have been reports of FND in Africa since the 1950s,
This was a retrospective study that did not employ specific outcomes measures, and some patient data were missing. Our study was also limited to a specific geographical area and to a single tertiary referral centre although patients were referred to this facility from throughout the province of KwaZulu-Natal.
Whilst the spectrum of FND is broad and heterogeneous, our study found the most common phenotype to be sensory impairment. A significant proportion of those with PNES had a family history of epilepsy, supporting the theory of ‘modelling’.
Abnormal MRI findings included cerebral atrophy, cerebellar atrophy, small vessel disease, sinusitis, periventricular non-specific lesion, chronic lacunas, degenerative spine disease, disc protrusions, old infarcts and an incidental pineal cyst. Only one patient had mesial temporal sclerosis reported on MRI; however, this patient was known with epilepsy and the reason for presenting was a hemiparesis rather than seizures.
Computed tomography brain findings included hemiatrophy, cerebellar atrophy, lacunar infarcts, incidental granulomas, calcification, arachnoid cyst, prominent pituitary gland and bilateral basal ganglia hyperintensities.
The authors would like to acknowledge Ms L. Viranna, clinical psychologist, Department of Psychology, IALCH, who performed neuropsychiatric assessments on a number of subjects.
The authors declare that they have no financial or personal relationships that may have inappropriately influenced them in writing this article.
L.N. conceived of the presented idea and wrote the manuscript. A.I.B. supervised the findings of this work, edited and contributed to the final manuscript.
The authors received no financial support for the research, authorship and/or publication of this article.
The data that support the findings of this study are available upon reasonable request from the corresponding author, L.N. The data are not publicly available because of information that may compromise the confidentiality of patient records.
The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the affiliated institutions.