Movement disorders and functional neurological disorders Flashcards
Definition of FND
sensory, motor, cognitive, or speech problems not fully explained by known neurological diseases, wherein signs and symptoms are involuntary
3 eras of evolution of FND
hysteria in the middle ages caused by a wandering uterus; conversion in the 20th century caused by past trauma; now FND with biopsychosocial origin
Conversion (origin of FND)
past stress and psychological trauma so bad that people have to convert it into a more acceptable form (i.e. physical symptoms)
Sex difference in FND
females > males
Onset of FND
sudden onset following a trigger (e.g. stressor, injury, medical procedure) with frequent history of medically unexplained symptoms (e.g. IBS, chronic fatigue)
Comorbidity of FND
high comorbidity with neurological and psychiatric disorders
5 subtypes of FND
functional weakness, functional tremor, non-epileptic seizure, functional speech disorder, functional cognitive disorder
Symptoms of functional weakness
face not affected; normal tone and reflexes; give-way weakness in arm; hoover’s sign in leg; dragging monoplegic gait
Symptoms common in PNES (non-epileptic or functional seizure)
eyes closed; greater than 2 mins duration; asynchronous limb movement; stopping/starting; crying
Symptoms rare in PNES
postictal disorientation; self-injury
Symptoms of functional cognitive disorder
vivid memory of forgetting; complete amnesia of significant events; memory perfectionism
Is FND a software or hardware problem?
software; due to a problem with functioning rather than lesions (e.g. hyperconnectivity between amygdala and PMC)
Pathophysiological model of motor FND
psychosocial and biological vulnerability interact to develop brain network dysfunctions then FND symptoms
Dysfunctions in FND
impaired emotional regulation (alexithymia); mismatch between predictions and sensory feedback (motor problems); impaired sense of agency
Positive evidence of FND in a person
internal inconsistency, incompatibility, distractibility
Neurophysiological ways of diagnosing FND
EEG for seizures and EMG coherence for tremor entrainment
Hoover’s sign for functional weakness
unable to lift weak leg but displays an automatic compensatory contraction on the weak leg when the good leg is pushed down
Tubular vision for functional blindness
same visual field size regardless of distance
4 treatments for FND
delivery of the diagnosis as treatment; education about FND; psychological therapy (e.g. CBT, psychodynamic); physiotherapy (e.g. motor retraining)
2 main kinds of movement disorders
parkinson’s and huntington’s
Onset of parkinson’s
between ages 45 and 70
Prevalence of parkinson’s
1% overall of people over age 65
Which groups are of higher risk of getting parkinson’s?
males > females; white > black > asian; familial risk
5 symptoms of parkinson’s
bradykinesia; rigidity; upper extremity resting tremor (initially unilateral then symmetric); postural instability with shuffling gait; expressionless or masked face
Bradykinesia
slowing of speech, motor movement, thinking
Rigidity
increased muscle tone/tightness at rest that stays fixed throughout range of motion (unlike spasticity); a sign of extrapyramidal motor dysfunction
Prognosis of parkinson’s
insidious onset with a highly variable rate of progression and high risk of developing dementia after age 80 (>50%)
Parkinsonism
conditions that share some symptoms and neuropathology as parkinson’s (e.g. Creutzfeldt-Jakob disease)
Neuropathology of parkinson’s
substantia nigra degeneration (in basal ganglia); marked neuronal loss with remaining cells having lewy bodies
3 ways to manage parkinson’s
L-dopa; dopamine agonists (e.g. bromocriptine); deep brain stimulation
L-dopa
amino acid precursor that is converted to dopamine; very effective first dose but declines as disease progresses
Epidemiology of huntington’s
affects 1-6 people per 100000 and is entirely hereditary (autosomal dominant)
Autosomal dominant
if one parent has huntington’s and the other doesn’t, the child has a 50% chance of getting it too
Which movement disorder is more rare?
huntington’s
Prognosis of huntington’s
insidious onset of symptoms in 30s-50s with a progressive course over 10-15 years
Clinical presentation of huntington
chorea, dystonia, subcortical dementia, early and prominent personality change
Neuropathology of huntington’s
increased number of cytosine-adenine-guanine (CAG) trinucleotide repeats on chromosome 4; bilateral caudate degeneration; frontal-subcortical circuits
Outcome of increased CAG on chromosome 4
protein misfolding then cell toxicity in the caudate
Treatment for huntington’s
none
How to diagnose huntington’s?
genetic testing
