Lecture 12: Movement Disorders Flashcards
What two parts of the brain are more associated with movement disorders?
- Basal ganglia
- Thalamus
What are the 3 NTs associated with movement disorders and what do they do?
- Dopamine: interneuronal communication and Inhibition of ACh
- GABA: Relaxes muscles and allows motor control
- ACh: NT at NMJ that increases neuronal excitability in CNS and Neuromodulator in PNS.
What is a tremor?
Impairment of regulation of voluntary motor activity
What is the most common movement disorder?
Tremor
What are the two causes of tremors?
- Alternating antagonist muscle action
- Synchronous antagonist muscle action
What are the types of tremors?
- Resting
- Action Postural: Attempting to maintain a specific posture (Think romberg)
- Action Kinetic: During voluntary movement
- Action Isometric: Muscle contraction against a stable object
What are the 3 types of action kinetic tremors?
- Simple kinetic: non-target directed (pronation-supination)
- Intentional: worsens approaching a target (eating)
- Task-specific: think writing
What frequencies are considered fast and slow for tremor?
- Slow: < 4 Hz
- Fast: > 12 Hz
What are the descriptors for tremors?
- Frequency
- Amplitude
What is the MC type of action tremor and when is it present?
Enhanced physiologic tremor present only when sympathetic activation
What resolves an enhanced physiologic tremor?
Removal of precipitating cause
What i the most common adult onset movement disorder and when does it occur?
Essential tremor around 35-45
What is the underlying pathophysiology for an essential tremor and what is a common factor in a lot of patients with ETs?
- Altered cellular activity in the ventral intermediate nucleus of the thalamus
- Family history
How does an essential tremor present?
- Bilaterally, hands and arms
- Postural and kinetic properties
- Most pronounced during drinking from a glass or F-N testing
- Resolves with rest
- Difficulty with fine motor activity
What exacerbates ETs?
- Emotion
- Hunger
- Fatigue
- Temperature extremes
What improves ETs?
Alcohol
What is the diagnostic criteria for ET?
- Isolated tremor consisting of bilateral UE action without other motor abnormalities
- 3y in duration
- W or w/o tremors in other locations
- Absence of other neurologic signs
How do you differentiate between enhanced physiological tremor and essential tremors?
Enhanced physiological tremors Worsen with caffeine and improve by removing the precipitating cause
When do we treat an ET?
Intermittent or persistent Disability
How do we treat intermittent ET?
- 1st-line: Propranolol and Primidone (slower onset)
- 2nd-line: xanax or klonopin
How do we manage persistent ET?
- 1st-line: propanolol or primidone daily. or both! (combo)
- 2nd-line: gabapentin, pregabalin, topiramate.
- 2nd-line: Neurologist for botox A or surgical intervention via deep brain stim or thalamotomy
When is surgery indicated for ET? CI?
- Indication: Failure of 2 oral regimens
- CI: dementia, severe cognitive impairment, or uncontrolled anxiety/depression
What are the two neurosurgical procedures for treatment of ET?
- Thalamic ventralis intermedius (VIM) nucleus DBS
- MRI-guided focused US thalamotomy (opposite of affected arm)
What activity tests for intention/kinetic tremor?
F-N testing, which should reveal increasing severity as the movement becomes closer to the target
What is a holmes-stewart maneuver?
Inability to control rebound from a release of flexion against resistance
Damage to what may cause intention/kinetic tremor?
- Midbrain
- Thalamus
- Cerebellum
- Pons
Balance related
How do you manage an intention tremor?
Refer to neuro for surgery
What is dystonia?
Sustained or repetitive involuntary muscle contractions, frequently causing patterned, twisting movements, and/or abnormal posture
What worsens dystonia and improves it?
- Worsening: Voluntary movement, stress & fatigue
- Improving: Active relaxation and sensory tricks
What is the underlying physiology that causes dystonia?
Involuntary contraction of both agonist and antagonist muscles
What does generalized dystonia usually involve at minimum?
Torso and limbs
What is the MC form of focal dystonia?
Cervical dystonia/torticollis
When is the MC onset for torticollis?
30-50
What causes torticollis?
Abnormal contraction of neck muscles (SCM, traps, posterior cervical)
What triggers UE dystonias?
Repetitive activities and task-specific dystonias
What are the MC types of task-specific dystonias?
- Writer’s cramp (MC)
- Muscician’s
- Putting in golf (yips)
When is the MC onset for UE dystonias?
10-50
What is involved with oromandibular dystonia? (OMD)
Masticatory, lingual, pharyngeal muscles
What two conditions are commonly associated with OMD?
- Blepharospasm
- Torticollis
How does blepharospasm usually present?
- Bilateral
- Synchronous
- Symmetric
What is involved in spasmodic dysphonia?
- Laryngeal muscles causing contraction of the vocal cords during speech
- Characterized by irregular and involuntary voice breaks
- pts often feel like they have to yell
How do we manage spasmodic dystonia?
- Refer to movement disorder specialist
- Botox (BoNT) injection
How do we treat generalized dystonia?
Trial of levodopa/carbidopa
What are the pharmacotherapies for generalized dystonia in adults?
- 1st-line: Clonazepam (GABA)
- Second-line: Baclofen (GABA agonist) or trihexyphenidyl (anticholinergic which increases dopamine release)
- Alternative second-line: VMAT2 inhibitor (-benazine and off-label use)
- Last resort: DBS
What are the pharmacotherapies for generalized dystonia in children?
- trihexyphenidyl
- Baclofen and BZDs
What is the MCC of infantile torticollis?
Damage or inflammation to SCM or traps.
R/o infectious etiology
How do you treat infantile torticollis?
- NSAIDs
- Soft cervical collar PT
Describe restless leg syndrome (RLS)
Idiopathic neurological movement disorder of limbs most associated with sleep complaint
What is the common demographic for RLS?
- Middle aged and older
- White women
- Familial
- Pregnancy
What nutrient deficiency is MC implicated in RLS?
Iron deficiency anemia
What are the risk factors for RLS?
- Frequent blood donation
- DM
- Chronic alcohol use
- Amyloidosis
- Motor neuron disease