Movement Disorders Flashcards
Why are basal ganglia disorders called “extra” pyramidal?
They do not affect the pyramidal system (AKA the corticospinal tract).
What are the main components of the basal ganglia?
The caudate, putamen, globus palidus, subthalamic nucleus, substantia nigra.
The striatum is composed of which two structures?
Caudate and putamen
The lenticular nucleus is composed of which two structures?
Putamen and Globus palidus
The most common movement disorder:
Tremor - rhythmic movement due to alternating contractions between agonist and antagonist muscles.
What is chorea/athetosis?
Dance-like: refers to irregular, asymmetric movements that are random and continuous.
Snake-like: slow twisting and writhing movements that typically affect more distal muscles of the fingers, arms, legs, and neck.
What is ballism?
Refers to violent, involuntary flailing of the extremities and can be thought of as an extreme form of chorea.
Dystonia:
sustained, abnormal posture caused by the simultaneous activation of both agonist and antagonist muscles.
Akathisia:
subjective sense of inner restlessness in which patients feel compelled to move continuously.
What is festinating gait?
Trouble initiating gait, but steps become faster and faster until there is trouble stopping.
What happens to resting tremors during sleep?
They vanish.
Parkinson’s Disease Symptoms (TRAP mneumonic):
Tremor, Rigidity (cogwheel), Akinesia/Bradykinesia, Postural instability.
What is often the first symptom of PD?
micrographia
What percent of neurons in the SN must be destroyed before symptoms start in PD?
80%
What is the pathological hallmark of PD?
Lewy Bodies: intracytoplasmic inclusions composed of alpha-synuclein.
What test was approved by the FDA in 2011 to aid with diagnosis of PD?
DaTscan: a contrast agent used with single-photon emission CT (SPECT) to detect DA transporters.
What is progressive supranuclear palsy?
A tauopathy characterized by midbrain atrophy and “reptilian stare.” Vertical gaze palsies, primarily with downward gaze, leads to spectacular falls early in the disease.
Common meds that induce parkinsonism:
high potency typical antipsychotics and antiemetics
What are two Parkinson-plus syndromes?
Multisystem atrophy cerebellar type and multisystem atrophy parkinsonian type. Shows atrophy of the pons and cerebellum.
Describe essential tremor:
Action tremor, often bilateral, often familial, improves with EtOH, more common than parkinson’s disease.
DA agonists carry which possible behavioral side effect?
Impulse control disorders such as pathological gambling or hypersexuality.
What is Sinemet?
“Sin emesis”- or without vomit. The role of the carbidopa is to prevent the conversion of levadopa to dopamine by dopa decarboxylase and therefore prevent emesis. However, carbodipa does not cross the blood-brain barrier, so the levadopa can be converted to dopamine in the CNS. Levadopa is used instead of pure dopamine, as dopamine also cannot cross the blood-brain barrier.
Orthostatic hypotension in PD patients can be treated with what?
Fludrocortisone
Which structure is a common target for DBS in PD?
Subthalamic nucleus, also thalamus and globus pallidus.
Lesions of the STN produce what?
Hemiballism: wild, flinging movements of the contralateral extremities.
Initial treatment for PD:
DA agonsists Requip/Ropinirole and Mirapex/Pramipexole
What is Stalevo?
Sinemet combined with catechol )-methyltransferase (COMT) inhibitors (entacapone, tolcapone).
Hot cross buns on MRI
Sign of Multiple system atrophy
Atrophy of the head of the caudate creating enlarged (boxcar) lateral ventricles and normal MRI:
Huntington’s Disease
Mechanism of inheritance for HD?
AD, CAG repeats
Each generation is affected earlier than the previous:
Anticipation
Which medication might prove useful in treating chorea in HD?
Haloperidol
The appearance of the midbrain on MRI is sometimes called the “face of the giant panda sign.”
Wilson’s Disease: enlarged liver and coarse tremor of arms (wing flapping tremor), movements are slow and patient is dysarthric.
Wilson’s Disease, metabolism of which metal is abnormal?
Copper: will see Kayser-Fleischer rings around periphery of cornea.
What can CO poisoning lead to?
Parkinsonism
Treatment for spastic torticollis:
Botulinim toxin
First-line treatment for restless leg syndrome:
DA agonists, such as roperinole
Every patient with restless leg syndrome should be tested for what?
Iron deficiency
Treatment for essential tremor:
Propranolol/Inderal
Treatment for akathisia:
Propranolol/Inderal
Treatment for NMS:
Bromocriptine (DA agonist), Dantrolene (calcium channel blocker)
What is copropraxia?
Copropraxia is a tic consisting of involuntarily performing obscene or forbidden gestures, or inappropriate touching
Most favorable risk/benefit ratio for patients with Tourette’s disorder:
Alpha adrenergic agonists (guanfacine/Tenex, clonidine)
