Movement Disorders

Question 1

Movement disorder?

Impaired coordination, usually 2/2 cerebellar lesions

Answer 1

Ataxia

cerebellar ataxia = due to cerebellar lesion

sensory ataxia = impaired proprioception and sensation of limbs

vestibular ataxia = lesions of vertebrobasilar system, leading to impaired balance; N/V, vertigo often present

Question 2

Movement disorder?

slow, writhing, repetitive movements that may affect the face, trunk, and extremities

Answer 2

Athetosis

Movements are not present during sleep

Question 3

Movement disorder?

Nonstereotyped, unpredictable, jerky movements that are variable in type and location across body parts

Answer 3

Chorea

Movements are present at rest, but can be increased by activity and stress

Associated w/ Huntington’s disease

Question 4

Movement disorder?

Extremely violent flinging of unilateral arm/leg

Lesion location?

Answer 4

Hemiballismus

Classically secondary to infart/bleed in contralateral subthalamic nuceli; can also be seen with nonketotic hyperglycemia

Movements are involuntary, involve the proximal portions of limbs, disappear with deep sleep

Question 5

Movement Disorder?

Sudden, jerky, irregular contractions of muscle

Answer 5

Myoclonus

Positive myoclonus: involuntary contraction
Negative Myoclonus: involuntary relaxation

Etiology: can be physiologic (sleep jerks, hiccups); essential (increasing w/ activity), epileptic, symptomatic (underlying encephalopathy/stroke), medication side effect, spinal myoclonus (group of muscles innervated by spinal segments that occur in spinal cord disorders - tumor, trauma, MS)

Tx: clonazepam, valproate, keppra

Question 6

Movement Disorder?

Involuntary coreiform movements of the face and tongue (such as chewing, sucking, licking, puckering, and smacking)

Answer 6

Tardive Dyskinesia

Due to hypersensitivity of dopamine receptos due to long-term blockade

Associated w/ long-term use of neuroleptic medication (20%)

There has been a decrease since the advent of atypical neuroleptics

Tx: benzos

Question 7

Movement Disorder?

sustained nonrhythmic muscle contractions that are rapid and stereotyped and often occur in the same extremity/body part during stress

Answer 7

Tics

Movements can be suppressed temporarily w/ concentration

More common in children than adults

Question 8

Movement Disorder?

Involuntary, rhythmic oscillation of a body part that can occur at rest or with action

Answer 8

Tremor

Question 9

Involuntary rhythmic motion while trying to maintain position of limb?

Answer 9

Essential tremor (postural or action tremor)

Benign
Tx: propranolol (or EtOH improve symtpoms)

Question 10

Involuntary rhythmic motion while trying to perform a limb action?

Answer 10

Intention tremor

Not present at rest

Etiology: cerebellar lesions
Tx: wrist weights, clonazapam

Question 11

Movement Disorder?

Involuntary, sustained, abnormal muscle contractions resulting in abnormal posturing. Movements tend to be patterned, occurring in recurrent locations than random

Answer 11

Dystonia

Subtypes: idiopathic, focal (torticollis, blepharospasm, Anterocollis, Retrocollis, Laterocollis, writer’s cramp), generalized (wilson’s disease, lipid storage disorders), neurodegenerative

Etiology: genetic, atipsychotic-related, intracranial lesion

Tx: Anticholinergics, baclofen, carbamazepine, clonazapam, botulinum toxin for focal dystonias

Question 12

Treatment for restless leg syndrome?

Answer 12

Levodopa-carbidopa, ropinirole, pramipexole (pro-dopaminergic agents)

Sometimes due to iron-deficiency anemia, can improve w/ iron supplementation

Question 13

Involuntary rhythmic motion while limb is at rest?

Answer 13

Resting tremor

“pill rolling tremor” often due to parkinson’s

3-6Hz

Question 14

Etiology of Parkinson’s disease?

Answer 14

Degeneration of the substania nigra dopamine-producing neurons –> decreased dopamine in the nigrostriatal pathway; resulting in loss of inhibitory input to the cholinergic system; allowing excessive excitatory output.

Question 15

MOA for levodopa-carbidopa?

Answer 15

L-dopa is a precursor of dopamine, given with carbidopa (a dopa decarboxylase inhibitor), which prevents systemic breakdown of L-dopa

Question 16

MOA for amantidine in parkinson’s disease?

Answer 16

potentiates release of endogenous dopamine, has mild anticholinergic activity

Question 17

MOA of benztropine in Parkinson’s disease?

Answer 17

anticholinergic

Question 18

Placement of DBS in Parkinson’s disease?

Answer 18

subthalamic nucleus of ventral intermediate nucleus of thalamus

Question 19

MOA of MOA-B or COMT inhibitors in Parkinson’s disease?

Answer 19

decrease dopamine breakdown

Question 20

Etiology of Huntington’s Disease?

Answer 20

Autosomal dominant CAG repeats that cause abnormal huntington protein to accumulate and cause degeneration of the caudate nucleus of the basal ganglia

Anticipation takes place (earlier and earlier presentation in subsequent generations)

Question 21

Treatment MOA in Huntington’s disease?

Answer 21

Aimed at decreasing dopamine and increasing ACh to help decrease movement (excess of dopamine increases movement)

Antipsychotics (anti-dopaminergic agents)
SSRIs for depression; suicide is common

Question 22

Autosomal recessive condition that presents in late childhood w/ problems walking, fatigue, changes in sensation and slowed speech?

Answer 22

Freidreich’s ataxia

Complications: neuromuscular scoliosis, wheelchair dependence, hypertrophic cardiomyopathy