Jack Chen, PharmD, BCPS, CGP, FASCP, FCCP
This session can be purchased in CPNP University.
Psychogenic neurologic disorders (PNDs) are commonly encountered in the ambulatory neurology practice setting.1-4 Mesha-Gay Brown, MD shared her expertise at CPNP 2016 addressing this topic in her session entitled Psychogenic Disorders in Neurology: Not Just in Your Head. Dr. Brown is an Assistant Professor of Neurology at the University of Colorado at Denver - Anschutz Medical Campus.
Current Understanding
PNDs are a functional disorder (i.e., not associated with structural abnormalities). The etiology is not well understood but it is believed that PNDs are a coping mechanism and response to stress-related factors (e.g., early life events and trauma).5 The neurobiological basis may be akin to mechanistic models of posttraumatic stress. Dr. Brown pointed out that in patients with PNDs, malingering is rare.
There are many types of PNDs (e.g., psychogenic non-epileptic seizures, psychogenic unresponsiveness and amnesia, psychogenic movement disorders, psychogenic sensory loss / anesthesia / paresthesia, psychogenic gait disorders, psychogenic pseudo-stroke or psychogenic paralysis / paresis). Psychogenic nonepileptic seizures (PNES) are a common type of PND and have the outward appearance of epilepsy but in the absence of physiological, EEG, or neuroimaging correlates. Dr. Brown emphasized that PNES are disabling and not adequately recognized or treated by healthcare professionals. The gold standard for diagnosing PNES is video EEG. The management of PNES is complex and a multidisciplinary approach results in better outcomes. Interventions for PNES include treating underlying psychiatric co-morbidities, cognitive behavioral therapy (either as individual or group therapy), and family therapy. Family therapy is important because family stressors need to be addressed. Dr. Brown stated that there is no role for antiepileptic drugs in the management of PNES (except for management of co-morbid psychiatric conditions).
Top 5 Myths
Dr. Brown dispelled 5 myths regarding PNDs.
Myth 1. Patients with PNDs are less disabled or distressed than other patients seen in neurology clinics with organic disease. Dr. Brown explained that patients with PNDs (cases) actually report worse physical health and mental health status compared to patients with organic neurological conditions (controls).1 In that study, unemployment was similar in cases and controls (50% vs. 50%), but cases were more likely not to be working for health reasons (54% vs. 37% of the 50% not working; OR 2.0; 95% CI 1.6 to 2.4) and also more likely to be receiving disability related state financial benefits (27% vs. 22%; OR 1.3; 95% CI 1.1 to 1.6).
Myth 2. Misdiagnosis of PNDs is high due to the lack of diagnostic tests. Dr. Brown reported in a systematic review of 27 studies, the overall misdiagnosis rate was 8.4% based on pooled data from studies published between 1965 - 2005.7 However, from the pooled data of more recent studies, the rate of misdiagnosis is approximately 4%. When broken down to specific time periods, the rate of misdiagnosis reduced considerably from 29% in the 1950s, to 17% in the 1960s, and to 4% in every decade thereafter. This improvement over time was unlikely to be due to improvements in diagnostic methods but rather due to poor methodology of earlier studies.6
Myth 3. Neurologists play a limited role in the management of PNDs once the diagnosis is made. Dr. Brown explained that the neurologist’s main goals should be to get a full picture of the physical symptoms and the day to day impact on function and that the neurologist is in a key position to initiate and coordinate optimal care.7
Myth 4. PNDs are diagnosis of exclusion. The Diagnostic and Statistical Manual of Mental Disorders, Fifth edition emphasizes identification of positive features typical of functional disorders. The requirements for presence of a psychological stressor determination of “not feigning” were removed. Dr. Brown stated that a psychological stressor is often not present and proving “not feigning’ is clinically impossible.8
Myth 5. Patients with PNDs whose symptoms resolve replace them with other medically unexplained symptoms (MUS). In a study of 187 patients with PNES, approximately 25% of patients developed a new MUS following the diagnosis of PNES, although most of them had a MUS pre-diagnosis. Patients with a history of health related psychological trauma whose PNES attacks continue after diagnosis are at particularly high risk of developing a new MUS. However, the study results did not support the hypothesis that PNES resolution is likely to be 'replaced' by other MUS.9 However, in patients who became PNES attack free, those who were drawing disability benefits were 5 times more likely to develop a new MUS (p = 0.011).
Take Home Messages
PNDs are a group of functional disorders that are commonly encountered in the ambulatory setting. Therapeutic approaches include management of underlying psychiatric co-morbidities, cognitive behavioral therapy, and family therapy.
References