Movement disorders Flashcards
Basal ganglia
General
Collection/clusters of nuclei (neurons)
1. Make Movements
2. Prevent unwanted movements
GABA
- inhibitory neurotransmitter
Glutamate
-excitatory neurotransmitter
DIRECT PATHWAY
Promotes voluntary movement in targeted muscles (from thought to the actual movement)
INDIRECT PATHWAY
Inhibition of movements in other muscles that do not contribute to overall wanted movement (unwanted/undesired motor activity)
striatum releases GABA to inhibiit globus palladus which then in inhibited and releases less GABA which excited Thalamus and promotes movement.
promotion of movement
??
Dopamine
Excited direct pathway
inhibits indirect pathway
Tic disorders
general
Tics are a neuropsychiatric disease common in children and adolescents
sudden twitches, movements (motor tic), or sounds that people do repeatedly (vocal tic). People who have tics cannot stop their body from doing these things.
defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM) based on type (motor or phonic) and duration of tics (sudden, rapid, nonrhythmic movements).
Motor tics
Simple
Simple: appears in one muscle group (nose twitching, blinking and rolling eyes balls, neck and head spasm, head shaking, head leaning back, lip biting, face grimacing or shoulder struggling)
motor tics
complex
Complex: simultaneously in more than 2 muscle groups (usually appears in motions when one is kicking skipping or jumping as he or she walks, imitating others’ movements, flaring nostrils and sniffing, self hitting and twirling in place)
Vocal tic
simple
Simple: dry cough, chocking sound, throat clearing, making animal noises, sniffling, muttering, saying syllables like, hm, ay, ah , ha
vocal tic
complex
Complex: Palilalia ( repletion of one’s own spoken words or sentences), Echolalia (repletion of words spoken by others), stuttering, coprolalia (saying obscene words or searing).
tic disorders
transient
when the tic symptoms temporarily and repeatedly appears and disappear before the age of 18
Chronic Tic Disorder
when either one of motor or vocal tic repeatedly appears and disappears continuously for more than a year
Complex Tic Disorder
- when vocal and motor tics are combined
Tourette Syndrome
when the symptoms of a complex tic last more than a year
tic disorders
causes
Dopamine system Dysregulation
Genetic Factor
Environmental Factors
Psychological factors
tic disorders
Tx
Medication: antipsychotic drugs (haloperidol, pimozide, risperidone…)
Behavior Therapy: relaxation training, habit reversal, family education
Operative treatment: deep brain stimulation, nerve surgery
Alternative treatments: cranio scaral balance therapy, TMJ balancing etc.
tremors
general
non-intentional rhythmic and oscillatory movements of a body part, which are the result of alternating or irregular synchronous contractions of muscles that have an opposite effect on a joint.
tremors
classifiction
Classification based on:
Distribution: which body part is affected
State dependent: Action (Essential Tremor), Rest (Parkinson’s disease)
Tremor frequency (the numbers of oscillations per second) (measured in Hertz)-
Amplitude (distance of movement)
Fine, course, ??
postural- hold a position against gravity
kinetic-
isometric- muscle contraction against something stationary like squeezing a stress ball.
Postural tremor
— Postural tremor happens when you try to hold a body part still, against the force of gravity. For example, your arms might shake if you hold them out in front of you.
Physiologic Tremor
Most common form of postural tremor
Rarely require medical attention, not usually noticeable
Typically affects the upper limbs and hands
Etiology:
Exaggerated physiological response: anxiety fatigue, fright, strenuous exertion.
Drugs like amphetamines, amiodarone, caffeine, valproate, theophylline, alcohol withdrawal
Metabolic: hypoglycemia, pheochromocytoma, thyrotoxicosis
Toxins: mercury
Postural- action
Essential Tremor:
tends to affect the hands and arms and can affect one side (left or right) more than the other.
Other sites: Head (30-40%), voice (15-20%)
No other neurological signs
No known cause (idiopathic)
Prevalence= about 5% in >65 years (males>females)
Family history in 50% of cases (aka familial tremors)
Age of onset: bimodal 10-20s and 40-60s
Can caused marked physical and psychosocial disability
Amplitude increases and frequency decreases with age
Improves with alcohol
postural - action
postural
Dx
Clinical. Exclude other possible causes of tremor based on any other symptoms
Certain medications or supplements often cause tremor, especially stimulants. Beta agonists, lithium, neuroleptics, thyroid drugs and caffeine
Alcohol withdrawal/benzodiazepine
Consider getting TFTs if the patient has symptoms of hyperthyroidism (moist skin, heat intolerance, tachycardia, tachypnea, menstrual abnormalities, goiter, exophthalmos, etc)
Consider imaging if the patient has other neurological symptoms especially gait abnormalities
EMG tremor analysis
EMG tracing
essential tremor
Tx
Depends on severity
Alcohol:
Many patients consume alcohol for its calming effect and prophylactically too
Alcohol has a central effect-it potentiates GABA activity
Drugs :
Reduce tremor amplitude with no effect on tremor frequency
Large amplitude and slow frequency tremor usually do not respond to pharmacological therapy
Propanolol -beta blocker- most effective drug
Primodine
Benzodiazapines (clonazepam, lorazepam, alprazolam)
Kinetic Tremor
general
This type of tremor happens when you are doing a goal-directed activity, such as writing or drinking from a cup.
“Simple kinetic tremor” remains constant throughout the action.
“Intention tremor” gets worse gradually as you get closer to your target (eg, whatever you are reaching for with your arm)
most associated woth cerebellar disfunction
kinetic tremor
Cerebellar Tremor
Typically associated with lesions or diseases that involved the cerebellum or its outflow pathways
Tremors are on the ipsilateral side of the body ( lesion on same side as tremor)
Can be combined with a postural tremor called a head titubation tremor
Amplitude of tremor increasing on approaching target during goal directed movement:
Finger-to-nose, finger-to-finger, and heel-to-shin testing results in worsening tremor as the extremity approaches the target
No drugs have been shown to reduce cerebellar tremors
from stroke or tumor
Isometric Tremor
general
Isometric tremor — This type of tremor happens when you contract a muscle against an unmoving object, for example, pushing against a wall or making a fist.
Rest tremors
general
Most typically seen in Parkinson’s disease
Tremor-dominant Parkinson’s disease is associated with-
Earlier age of onset
Less cognitive decline
Slower progression than the postural instability and gait difficulty variant
The Parkinson’s Disease resting tremor is due to abnormal synchronicity of basal ganglia and thalamic neuronal activity
rest tremor
Rest tremor in upper limb, fingers and hand:
Pill rolling 5Hz
Usually symmetrical
Abolishes by movement but may reappear in new posture
Leg, tongue, lip and jaw may also be involved
Exacerbation by emotional stress
Response to antiparkinsonian drugs