Movement disorders Flashcards
What two parts of the brain is thought to be responsible for movement?
- Basal Ganglia - function is not fully known - thought to be linked to initiation and execution of movements
- Thalamus - transmits signals from the cerebral cortex to the spinal cord
MOA of dopamine
- NT involved in interneuronal communication
- Inhibits release of Ach at nerve terminal
- Helps to make smooth motor movements and motor control
inhibitory neurotransmitter that relaxes muscle and allows motor control
GABA
Gamma-aminobutyric acid
a NT found at neuromuscular junction and in the autonomic ganglia. Increased neuronal excitability in the periphery and functions as as neuromodulator in the CNS
Acetylcholine
An involuntary, rhythmic, and oscillatory movement of a body part
Tremor
Can affect hands, arms, head, face, voice, trunk, and legs
how are tremors caused?
either alternating or synchronous contractions of antagonistic muscles
Neural dysfunction or lesions that result from injury, ischemia, metabolic abnormalities, or a neurodegenerative disorder.
MC movement disorder
tremor
how are tremors categorized?
resting or action
this tremor occurs in a body part that is fully supported, relaxed, and not voluntarily activated
resting tremor
Occurs in an attempt to maintain a specific posture or position against the force of gravity
what type of tremor?
Action
Postural
Occurs during any voluntary movement
what type of tremor
action kinetic
Occurs during a muscle contraction against a rigid, stationary object
what type of tremor
action isometric
what are the 3 subcategories of action kinetic tremor?
- Simple Kinetic: during voluntary movements that are not target directed (e.g. pronation-supination)
- Intentional: worsens as the body part approaches its target (e.g. eating)
- Task-specific: occurs during a specific task (e.g. writing)
descriptors of tremors
- Frequency Hz / sec
- < 4 (slow)
- 4-8
- 8-12
- >12 (fast) - Amplitude - ROM
- low (smaller movement)
- high (larger movement)
A very low-amplitude, high-frequency (8 to 12 Hz) physiologic action tremor in the upper limbs.
MC type of action tremor
Enhanced physiologic tremor
Enhanced physiologic tremor is present only when there is ?
sympathetic activation
- stress, anxiety, excitement, muscle fatigue
- F, hypoglycemia, thyrotoxicosis, pheochromocytoma
- alc or opioid withdrawal
- meds, drugs, and substances
management for enhanced physiologic tremor?
- Tremor resolves when precipitating factor is removed
- Treat/remove underlying causes
Most common adult onset “neurological” movement disorder
essential tremor (ET)
pathophys of ET
not fully understood - altered cellular activity in ventral intermediate (VIM) nucleus of thalamus
epidemiology of ET
- Incidence increases with age
- Mean age - 35-45 years
- Usually manifests by 65 y/o
- FHx present 30-70 % of pts
presentation of ET
- MC bilaterally affects hands and arms
- > the head, voice, face and trunk - Both postural & kinetic properties
- arms postured against gravity or during goal-directed movements (e.g. drinking from a glass or F-N testing)
- Resolves w/ rest or if extremity is fully supported - trouble w/ fine motor activity - eating, drinking, pouring, writing, typing, texting, and applying makeup
- Exacerbated by emotion, hunger, fatigue, temperature extremes - NOT by caffeine
- Improves w/ alcohol (small)
- Progressive over time
- F-N testing - mild or absent tremor until after the target is reached
You suspect an essential tremor in your patient but they have more of a isolated head or voice tremor, what is your next step?
Find other cause! - Dystonic head tremor, Spasmodic dysphonia
isolated head or voice tremor excludes ET
How to DDX of ET
- Enhanced physiologic tremor - worsened by caffeine, resolves when precipitating factor is removed
- Parkinson disease - at onset unilateral resting tremor, rigidity, bradykinesia
- Dystonic head tremor - isolated head tremor
- Spasmodic dysphonia - isolated voice tremor
- Cerebellar tremor - intention related qualities and other signs cerebellar dysfunction (ataxia)
- Wilson’s disease - asymmetric tremor, other neurologic sx (dysarthria, dystonia, chorea etc.)
How to DX ET?
made clinically based upon hx and PE
Labs for ET
USED TO R/O SECONDARY CAUSES OF TREMOR
CMP - electrolyte imbalance
Thyroid function tests - hyperthyroidism
Serum ceruloplasmin - Wilson disease¹
Diagnostic Criteria for ET
International Parkinson and Movement Disorder Society (IPMDS) task force
- Isolated tremor consisting of bilateral upper limb action (kinetic and postural) tremor, w/o other motor abnormalities
- At least 3 years in duration
- w/ or w/o tremor in other locations
- Absence of other neurologic signs (dystonia, ataxia, or parkinsonism)
management for ET
Tx recommended for intermittent /persistent disability d/t tremor
Intermittent:
- 1st line - Propranolol (30 min prior to activity); (Alt) Primidone qhs
- 2nd line - BZD - alprazolam (Xanax), clonazepam (Klonopin) - reduces anxiety that worsens ET - not recommended for chronic use
Continuous
- 1st line - propranolol BID; primidone; Combo
- 2nd line - Anticonvulsants: gabapentin (Neurontin), pregabalin (Lyrica), topiramate (Topamax)
- 2nd line - refer to neurologist
- Botox into affected muscle - reserved for head tremors unresponsive to pharm
- Surgical intervention: Deep brain stimulation vs thalamotomy
indication for surgical therapy for ET
disabling tremor with failure of 2 oral regimens
CI for surgery in ET
dementia or significant cognitive impairment¹, uncontrolled anxiety/depression
What is VIM nucleus deep brain stimulation
Implantation of an electrode into the VIM nucleus connected to a pulse generator implanted in the chest wall below the clavicle which delivers unilateral high-frequency electrical stimulation when activated
For ET
what is MRI-guided focused ultrasound thalamotomy
Uses high-energy US beams to create a permanent lesion in the VIM nucleus of the thalamus - performed on the opposite side of the most severely affected arm
for ET
A target-directed coarse tremor that worsens when closest to the terminal target
Intention (kinetic) tremor
Frequency - 3 to 4 Hz
How would an Intention (kinetic) tremor present on a finger-to-nose test?
Abnormal finger-to-nose testing
* No tremor at start but become more severe as directed movement advances to target
* may continue for several beats after the target has been reached
neurological presentations of intention tremor
- Nystagmus
- Dysarthria - poor articulation and slurred speech
- Dysmetria - overshoots or undershoots their target
- Dysdiadochokinesia - abnormal RAM’s
- Holmes-Stewart maneuver: abnormal finding - inability to control rebound from a release of flexion against resistance (about to punch yourself)
- Heel shin ataxia
- Ataxic gait
Etiologies and associated conditions of Intention (kinetic) tremor
6
- Damage to midbrain, thalamus, cerebellum, or pons
- MS
- Stroke
- Severe forms of ET
- Wilson dz
- Mercury poisoning
work up and management for inention tremor
- Work-up - Same as ET to r/o underlying etiologies
- Management
- No successful medical treatment exists
- Refer to neurology - surgical intervention as in ET
Sustained or repetitive involuntary muscle contractions, frequently causing patterned twisting movements and/or abnormal posture
Dystonia
involuntary contraction of both agonistic and antagonistic muscles
what worsens and improves Dystonia
Worsened by voluntary movement, stress and fatigue
Improved with active relaxation and sensory tricks
Dystonia related conditions are classified based upon what factors?
5
- age
- body distributrion
- Anatomical location
- Inherited or Acquired
- Primary or Secondary
- Primary: no other neuro s/s
- Secondary: d/t underlying disease
other neuro s/s
ages of dystonia
“Dystonia related conditions classified based upon various factors” 5
- Infancy: birth to 2 years
- Childhood: 3 to 12 years
- Adolescence: 13 to 20 years
- Early adulthood: 21 to 40 years
- Late adulthood: >40 years
Generalized dystonia involves multiple areas of the body often including the ___ and ____
torso and limbs
cause of generalized dystonia
- Genetic: Childhood onset; Adolescent onset dystonia
- Acquired - birth injury, exposure to certain drugs, head injury, infection
MC focal dystonia
Cervical dystonia (aka. torticollis)
- Contraction of neck muscles causing the head to deviate to one side - SCM, traps, and posterior cervical muscles
- MC onset 30-50 years of age
subtypes of Cervical dystonia (aka. torticollis)
torticollis, retrocollis, anterocollis, laterocollis
more than one may occur simultaneously
- Contraction of muscles in the UE brought out by specific activities
- involuntary flexion, extension, and/or rotation of the fingers, wrist, elbow and/or shoulder
- triggered by repetitive activities
Upper Extremity Dystonias
Onset is usually 10-50 years of age
Task-specific UE dystonias and which is MC?
- handwriting/typing (writer’s cramp) - MC
- playing a musical instrument (musician’s cramp)
- putting in golf (the yips)
Involuntary movements involving masticatory, lingual, and pharyngeal muscles.
Oromandibular Dystonia (OMD)
* Jaw clenching, jaw opening, jaw deviation, and tongue protrusion
* Difficulty speaking and swallowing
* Cosmetically disfiguring
OMD is often associted with what other movements/conditions?
blepharospasm & torticollis
Contraction of the eyelids causing increased blinking and involuntary eye closure that may interfere with daily functions
Blepharospasm
bilateral, synchronous, and symmetric, can be asymmetric
Task-specific focal dystonia involving the laryngeal muscles causing contraction of the vocal cords during speech
Spasmodic dysphonia
Characterized by irregular and involuntary voice breaks that interrupt normal speech
Pt may feel they have to “yell” or use more energy than normal to talk
Spasmodic dysphonia
general management for dystonia
Refer to a movement disorder specialist (neurologist with additional training)
No cure, management is symptomatic only
Focal Dystonia Management
Botox injection - for focal dystonias ONLY
Injection into the affected muscle(s) weakens the muscle
MOA of botoxin
blocks the release of Ach at the NMJ
Indicated for focal dystonias only
management for generalized dystonia
- for ALL: Trial of levodopa/carbidopa
- Adult
- 1st line: Clonazepam (Klonapin) - works on GABA receptor
- 2nd: baclofen (GABA agonist)
- 2nd: Ach - trihexyphenidyl (Artane) - Children
- 1st-line: trihexyphenidyl
- 2nd: baclofen & BZD’s - 2nd line: VMAT2 inhibitor: tetrabenazine (Xenazine), deutetrabenazine (Austedo)
- Deep brain stimulation (DBS) - last resort for those who fail more conservative therapies
-abenazine = VMAT2i
MOA of levodopa/carbidopa
levodopa is converted into dopamine in the CNS; carbidopa prevents levadopa from being broken down too early
trihexyphenidyl - MOA
is not well understood - muscarinic receptor antagonist which increases striatal dopamine release and efflux
for Generalized Dystonia Management:
MOA of VMAT2 inhibitor
depletes dopamine (and other monoamines) at the neuron synapse reducing the excitability of the neurons
cause of infantile torticollis
- pain, torticollis, and decreased range of motion
- MC d/t damage or inflammation to the SCM or trapezius
- must R/O infectious etiologies - strep pharyngitis, cervical adenitis, retropharyngeal abscess, parapharyngeal abscess, and viral URI
management for infantile torticollis
Treat underlying disorder if appropriate
Tx with NSAIDS, soft cervical collar physical therapy
Idiopathic neurological movement disorder of the limbs often associated with a sleep complaint
Restless Leg Syndrome (RLS)
Onset - may begin at any age, but MC middle aged or older
epidemiology of RLS
- 5-15% of the general population in the US
- Familial in 25 – 75%
- Women > Men (2:1)
- Caucasian > Black American
- Increases with pregnancy
pathophys of RLS
- Unknown
- Theories - genetic component, lack of dopamine uptake and impaired iron homeostasis
possible causes of RLS
- MC idiopathic
- May be secondary to:
- Nutrient deficiency: Iron, Mg, B12, Folate
- Renal failure (uremia)
- Neuropathy
- Hyperthyroidism
- Spinal cord pathology
- Traumatic spinal cord lesions, demyelinating or postinfectious lesions, tumors
- Pregnancy
- Parkinson disease (PD)
- Multiple sclerosis
risk factors for RLS
- Frequent blood donation
- DM
- Chronic excessive alcohol use
- Amyloidosis
- Motor neuron disease
presentation of RLS
- often have difficulty describing sx - “need to move,” “crawling,” “tingling,” “restless,” “cramping,” “creeping,” “pulling,” “electric,” “tension,” “discomfort,” “soreness,” and “itching”
- Not painful; bothersome
- Irresistible urge to move the legs w/ or w/o uncomfortable sensations - UE can also be affected
- Temporarily relief after movement (walking or stretching)
- Worse in the evenings or during times of inactivity
- Not associated with other chronic disease sx - myalgia, venous stasis, leg edema, arthritis, leg cramps, positional discomfort, medication side effect, drug abuse or habitual foot tapping
- Majority - periodic movements of sleep (PLMS): involuntary, forceful dorsiflexion of foot lasting up to 5 sec and occurring every 20-40 sec throughout sleep
- Daytime fatigue
- Insomnia
- Involuntary, repetitive, periodic, jerking limb movements - both awake and at rest
- Anxiety/depressive sx related to chronic sleep deprivation - Associated with a 2-3 fold higher risk of suicide and self-harm
Aggravating factors of RLS
- Caffeine
- Sleep deprivation
- Certain drugs - inhibits dopamine
- Antihistamines (benadryl and other OTC sleep aids)
- Dopamine antagonist - antipsychotics; anti-nausea meds - metoclopramide (Reglan)
- Antidepressants - TCA’s, SSRIs SNRIs
whcih antidepressant is less likely to exacerbate RLS
bupropion
DDX for RLS
- Volitional movements: foot tapping/bouncing, leg rocking; no circadian rhythm, no “urge”, easily suppressed
- Akathisia: generalized restlessness, no subjective “sensation” complaints; less relief from movement, less likely to have circadian pattern
- Nocturnal leg cramps: muscle spasms of the feet/calf; sudden onset, short duration
- Positional discomfort: no subjective “sensation” complaints
- Leg Pain: no “urge” to move; no relief with position change
labs for RLS
- Iron, Ferritin, transferrin saturation - all patients
- If secondary RLS is suspected, look for underlying etiology
* CBC
* Blood urea nitrogen (BUN)/Creatinine
* Fasting blood glucose
* Magnesium
* TSH
* Vitamin B-12
* Folate
The diagnosis is clinical
Indication for pharmacotherapy for RLS
sx for ≥ 3 nights/wk
pharm options for RLS
-
Iron replacement if the fasting serum ferritin level ≤75 mcg/L
- Ferrous sulfate 325 mg orally every other day or daily - w/ Vit C or a glass of OJ²
- Repeat iron panel after 3-6 mo
- DC therapy when ferritin level is >75 mcg/L and Fe saturation > 20% - Alpha-2-delta calcium channel ligand: gabapentin (IR) (Neurontin), pregabalin (IR) (Lyrica), gabapentin enacarbil (ER) (Horizant)
-
Dopamine agonist: pramipexole (Mirapex), ropinirole (Requip)
- oral therapy, 2 hours before bed - Rotigotine (Neupro) transdermal patch - 1 mg patch per day
nonpharm options for RLS
Keep the mind busy - working on a computer or doing crossword puzzles, at times of rest
Removal of exacerbating medications (if applicable)
Moderate regular exercise
Avoid caffeine
Good sleep hygiene
SE of Alpha-2-delta calcium channel ligand
gabapentin (IR) (Neurontin), pregabalin (IR) (Lyrica), gabapentin enacarbil (ER) (Horizant)
- SI/behaviors, depression, mental fog, dizziness, weight gain, dependence, addiction
- Excretion by the kidneys
- DEA: Controlled substance - risk for diversion
SE of Dopamine agonist
- nausea, lightheaded, fatigue usually resolve 10-14 d
- risk of impulse control disorder
- risk of augmentation
taper therapy if DC
an overall increase in RLS symptom severity with increasing doses of oral dopamine agonists
Augmentation
Pt on dopamine agonist is now experiencing earlier onset and increased intensity of their RLS
topographic spread of sx to other body parts, like their trunk and arms
shorter duration of drug action
what is your dx and management?
Augmentation
assess iron stores and replace if necessary
switch to alpha-2-delta calcium channel ligand
Refractory disease - refer to neurology
risks of augmentation
higher doses of therapy
longer duration of use
lower iron stores
delivers peroneal nerve stimulation via bilateral therapy units worn externally just below the knee, over the head of the fibula.
Tonic motor activation (TOMAC)
RLS
A common genetic neurological disorder characterized by chronic motor and vocal tics beginning before adulthood
Tourette Syndrome (TS)
repetitive, stereotyped movements or vocalizations, such as blinking, sniffing, facial movements, or tensing of the abdominal musculature
epidemiology of TS
- Onset in childhood – 2-15 y/o; Average age 6 – 11 y/o (96% of dx)
- Males > Females (4:1)
- 3 out of 1,000
- New research suggests genetic inheritance through a dominant gene
possible RF for TS
Smoking during pregnancy
Complications during pregnancy
Low birth weight
pathophys of TS
unknown - hypothesis: a disorder of neurotransmission in the cortico-striatal- thalamic-cortical (mesolimbic) circuit, which leads to disinhibition of the motor and limbic system
clinical presentation of TS
Tics - sudden, brief, intermittent movements (motor tics), utterances (vocal or phonic tics) or sensations (sensory tics)
- Exacerbated by fear or anxiety
- Known to be involuntary, but can temporarily be voluntarily suppressed
- May be preceded by urges, sensations, or thoughts
