Functional Neurologic Disorder Flashcards
other names for functional neurologic disorder
Functional Motor Disease, Functional Neurological Symptoms Disorder, Somatoform Disorder, Psychogenic Movement Disorder, Hysterical Paralysis, or Conversion Disorder
functional neurologic disorder
Neurological symptoms affecting movement that
are caused by a loss of control over movement
rather than a structural disease process in the
neurological system
what are symptoms due to in functional neurotic disorder?
Symptoms are due to an unconscious expression
of a psychological conflict or need (patient may
not be aware of this conflict/need)
what is functional neurologic disorder characterized by?
involuntary but learnt habitual movement patterns driven by abnormal self-directed attention
what is FND triggered by?
physical or psychophysiological events such
as injury, illness, panic and dissociation with panic
what is FND mediated by?
illness beliefs and expectations
motor functional neurologic symptoms include:
weakness, tremor, jerks, dystonia, gait disorder, paralysis of one or more limbs, ataxia, tics, or a combination of symptoms
non-motor functional neurologic symptoms include:
sensory disturbance, memory complaints, pain, fatigue, or dissociative seizures
what happens when symptoms are reinforced by
social support from family and friends or by avoiding the underlying emotional stressors?
high levels of disability and distress, poor
prognosis, high financial burden
types of FND
Motor FND
FND with Sensory Dysfunction
Axial FND
Speech FND
Paroxysmal FND with seizures
Motor FND
- sudden onset of symptoms
- functional weakness
- functional tremor
- functional parkinsonism
- functional dystonia
when do symptoms decrease for Motor FND
with distraction of patient, increase with attention to symptoms, excessive fatigue, or demonstrations of effort
functional weakness of motor FND
- variability in severity over time and discordant performance between assessments
- May be global or limited to parts of the body- just lower extremities mimicking SCI or just on one
side of the body mimicking a stroke
motor FND - functional tremor
variable frequency, characteristic response to externally cued rhythmic movements
motor FND - functional Parkinsonism
excessive slowness without decrement and fatigue
oInconsistent rigidity, normal speed with spontaneous movements
FND with sensory dysfunction
- Midline splitting of vibration sense across a single bone such as forehead or sternum
- Complete hemianopsia with both eyes open during visual field testing
- Persistent perceptual postural dizziness (PPPD)
PPPD in FND with sensory dysfunction
o Provided by upright posture, active/passive motion, exposure to moving visual stimuli or complex visual patterns
o Triggered by an episode of acute dizziness such as vestibular neuritis or panic attack
Axial FND
- Disorders of gait and posture
- Excessive gait slowness, astasia-abasia, knee buckling
- Excessive demonstration of effort during ambulation
- Functional trunk postural abnormalities
what is astasia-abasia
inability to stand or walk despite sparing of
the motor function to do so
functional trunk postural abnormalities in axial FND
Myoclonic jerks affecting the trunk or fixed forward flexion of the thoracolumbar spine
Speech FND
Dysfluency similar to stuttering, articulation deficits, visible demonstration of excessive effort, prosodic
abnormalities (foreign accent)
o Aphonia, dysphonia
Paroxysmal FND with seizures
- Episodic
- Paroxysmal akinesia
- Paroxysmal hyperkinesias
PNES vs epileptic seizures
PNES tends to have a long duration of shaking episodes, fluctuating course of seizures, asynchronous limb movement, pelvic thrusting, side-to-side head movements, closed eyes, ictal crying, and recalling of ictal events
incidence of FND is higher with what population?
patients with 1st degree relatives with psychiatric/medical disorders or history of
sexual/emotion/physical abuse
is FND more common in men or women?
60-70% are women
what do psychodynamic models emphasize?
a symptom may either suppress an emotion
or serve to resolve dilemmas, support important interpersonal relationships, or escape interpersonal conflicts
attentional dysregulation
o Hierarchical information flow in the nervous system is based on the integration
between bottom-up sensory information and top-down predictions about the
nature of the expected sensory information
o Differential weighting of the 2 streams of information leads to abnormal
predictions about sensory data with abnormal perceptions or movements
o Attention is underscored by the suppression of symptoms with distraction
o Practice of deflective attention away from the affected area
integrative cognitive model for PNES
- inherent responses to emotions, ideas about
illness, and illness models contribute to the formation of a symptom which may be
activated by arousal or internal/external stimuli perceived as threatening - Symptoms may be further facilitation by illness awareness, health anxiety, and excessive threat vigilance
once functional symptoms are formed …..
regardless of the initiating mechanism, phobic avoidance, affective disorders, and brain plasticity may be perpetuating features
pathophysiology - neurobiological
Due to the relative disconnection between the
SMA and areas that would usually select or
inhibit movement (prefrontal cortex), movements
occur without a normal feeling or sense of
agency/control
Abnormalities activated via negative emotional
stimuli may be associated with what?
abnormally increased activation in areas involving emotion recognition and self-awareness
(amygdala/cingulate gyrus) and in networks
related to emotion processing
Feigned vs. Functional Weakness on neuroimaging
o Feigned: no activation seen when participants are given command to move
o Functional: Normal activation within areas associated with movement preparation was accompanied by activation within the prefrontal cortex that be unexpected during voluntary movement activation
Physiological studies: Electromyography and Motor Evoked Potentials
o People that have a functional neurologic disorder and were asked to imagine moving the affected limb had smaller motor evoked potentials compared to healthy subjects
o Findings suggest that although structural motor pathways are preserved in motor functional neurological disorders, there is an alteration in the
pathways involved in motor planning
o Conclusion: Normal function of the primary pathways (motor/sensory) and alterations at the level of premotor/sensory association cortex
processing
predisposing vulnerabilities - biological
- Gender- Female; Intellectual disability, Epileptic Seizures, Other nervous system vulnerabilities; Comorbid medically unexplained syndromes (chronic fatigue, pain, or GI complaints)
predisposing vulnerabilities - psychological
Comorbid mood and anxiety disorders, dissociation, alexithymia, insecure attachment, illness perception, Temperament and maladaptive
personality traits
predisposing vulnerabilities - psychosocial
Family functioning, adverse life events, financial status, peer support, attitudes toward health and disease
precipitative factors - biological
- Abnormal physiological events (sleep deprivation, hyperventilation, palpitations), acute physical pain or limb injury, head trauma
(especially mild TBI)