Hyperkinetic Movement Disorders (18, Part 2)

Question 0

What are three hyperkinetic disorders that are common and we were taught about?

Answer 0

1. Huntington’s disease
2. Tourette’s syndrome
3. Primary (idiopathic) dystonia

Question 1

What characterizes hyperkinetic disorders?

Answer 1

Excessive, unwanted, or distorted movements

Question 2

What type of inheritance pattern does Huntington’s have? What chromosome has the mutation (which arm)?

Answer 2

Autosomal dominant - short arm of chromosome 4

Question 3

What type of mutation is responsible for the Huntingtin protein being defective?

Answer 3

Expanded trinucleotide CAG repeat –> altered Huntington protein and consequent neuronal damage

Question 4

What is the typical age range of onset in Huntington’s? Life expectancy after onset?

Answer 4

35-45 typically

Life expectancy is 15-20 years after symptom onset

Question 5

What is associated with a more rapid course of Huntington’s?

Answer 5

Younger age of onset - usually have larger number of repeats and this more severe pathological process

Question 6

What symptom is the neurological hallmark of HD? Why is dysarthria a related symptom?

Answer 6

Chorea - rapid, random jerky movements that seem to flow from one movement to another
*dysarthria is related! because it is due to choreiform movements of the tongue and lips! which interfere with speech

Question 7

As HD progresses, what replaces the chorea that is typically seen at the outset?

Answer 7

Replaced by dystonia (sustained, involuntary muscle contractions) and eventually rigid/akinetic Parkinsonism

Question 8

With juvenile HD (onset in teenage years to due to lots of CAG repeats), what is the usual presenting symptom in contrast to normal HD?

Answer 8

Usually develop Parkinsonism right from the onset rather than chorea

Question 9

What 4 behavioral changes might be seen as initial presenting features of Huntington’s?

Answer 9

1. Impulsiveness
2. Irritability
3. Obsessive behavior
4. Aggression
   * depression also very common, some commit suicide

Question 10

What kind of dementia is seen as a behavioral symptom in Huntington’s?

Answer 10

Subcortical dementia characterized by executive dysfunction–> impairment of planning, organizing, reasoning, judgment

Question 11

What two oculomotor disturbances may be seen with Huntington’s?

Answer 11

1. Difficulty iniatiating/slowed saccades

2. Gaze impersistence (cant maintain gaze)

Question 12

What two structures in the brain show neuronal loss and gliosis (atrophy) in Huntington’s?

Answer 12

1. Striatum (especially the caudate)

2. Cortex

Question 13

What age range is typically seen for Tourette’s syndrome? Which sex is predominant?

Answer 13

2-15; does NOT present adulthood, in fact, usually symptoms diminish by then
* male predominance (3:1)

Question 14

Is Tourette’s a genetic disease?

Answer 14

Almost certainly inherited, but genetic mutations have only been identified in a small fraction of patients

Question 15

What is a hallmark of the motor, sensory, and vocal tics seen in Tourette’s?

Answer 15

The complement changes, so some dispappear and are replaced; also the frequency and severity of tics waxes and wanes over time

Question 16

What 2 kinds of tics must be present as part of the formal diagnostic criteria for Tourette’s?

Answer 16

Multiple motor tics and at least one vocal tic (don’t have to be present concurrently)

Question 17

What must be frequency of tics be according to the formal diagnostic criteria for Tourette’s?

Answer 17

Many times a day or intermittently over the course of a year, with no tic-free interval greater than 3 consecutive months

Question 18

What age must onset occur before?

Answer 18

18

also the disorder must not be explainable by any other condition

Question 19

What is echopraxia?

Answer 19

Involuntary repetition or imitation of another person’s movement

Question 20

What is copropraxia?

Answer 20

Involuntary performance of obscene or forbidden gestures

Question 21

What is echolalia?

Answer 21

Involuntary repetitions of vocalizations made by another person

Question 22

What is palilalia?

Answer 22

Rapid repetition or echoing of one’s own words

Question 23

What is coprolalia?

Answer 23

Involuntary swearing, or utterance of obscene, socially inappropriate or derogatory words
*actually quite rare in TS; only ~10%

Question 24

What two behavioral conditions often occur with Tourette’s?

Answer 24

1. ADHD (more commonly seen concurrently)
2. Obsessive-Compulsive disorder
   * compulsions usually about sex, counting, symmetry, and violence

Question 25

What pathological abnormality is seen in Tourette’s?

Answer 25

None identified to date (maybe prefrontal cortex, unproven)

*also no identifiable neuron helical abnormalities

Question 26

What is dystonia?

Answer 26

Sustained muscle contraction that produces sustained, sometimes repetitive twisting movements that result in abnormal postures

Question 27

What is the difference between generalized and focal dystonia?

Answer 27

Generalized refers to involvement of muscles throughout the body; focal refers to an isolated muscle group or area of body

Question 28

What is the inheritance pattern for Primary Generalized Dystonia? What ethnic group is it most common in?

Answer 28

Autosomal dominant - most common in Ashkenazi Jews

Question 29

At what time of life to people usually present with primary generalized dystonia?

Answer 29

Childhood

Question 31

Which gene on which chromosome is mutated in primary generalized dystonia?

Answer 31

DYT1 gene on chromosome 9

Question 32

What protein is ultimately affected in primary generalized dystonia?

Answer 32

Torsion A (is due to a glutamate deletion)

Question 33

The initial presentation of primary generalized dystonia is usually _____ and is an action dystonia, what does this mean?

Answer 33

Focal

Action dystonia - dystonia induced by movement

Question 34

Which extremity is usually involved 1st in primary generalized dystonia?

Answer 34

Lower extremity –> ankle inversion, plantar flexion of the toes seen commonly
*over time will progressively spread to also involve axial musculature

Question 35

What two postural abnormalities may develop that give a “dromedary” appearance to the gait?

Answer 35

1. Flexion at the hips

2. Extension of the neck

Question 36

What other two postural abnormalities may be seen in primary generalized dystonia?

Answer 36

1. Exaggerated hip abduction

2. Knee hyperextension

Question 37

What happens to cognition, strength, and sensory modalities in individuals with primary generalized dystonia?

Answer 37

They remain normal; dystonia (along with the gait/posture changes) usually remain the sole feature, except for a select few that develop a tremor
*no pathological or neurochemical changes have been identified

Question 38

At what time in life does Primary Focal Dystonia usually appear? What genetic component does it have?

Answer 38

Usually in adulthood

*a few have a genetic basis identified, but tradionally assumed to be sporadic

Question 39

Is primary focal or primary generalized dystonia more common?

Answer 39

Primary focal dystonia is more prevalent (30 vs. 3 /100,000)

Question 40

Muscles in what region of the body are typically affected in primary focal dystonia?

Answer 40

Muscles above the waist

Question 41

How does the degree of dystonia progress?

Answer 41

Usually progresses in severity over a number of years then becomes static (doesn’t improve but doesn’t get any worse either)

Question 42

Some individuals have a task-specific dystonia, what does this mean?

Answer 42

The dystonia is only evident when a specific task is attempted, such as writing or playing a musical instrument

Question 43

What is a peculiar characteristic in focal dystonia in terms of alleviating the dystonia?

Answer 43

Sometimes “sensory tricks” can alleviate - i.e. Alleviation of a cervical dystonia by touching the cheek on the side opposite to which the neck is turning

Question 44

What is a dystonia that in involves specifically the muscles around the eyes, resulting in involuntary eye closure?

Answer 44

Blepharospasm (if severe may produce a functional blindness)

Question 45

What is the dystonia called when it affects primarily the muscles around the mouth?

Answer 45

Oromandibular focal dystonia

-May result in either forced mouth opening or forced mouth closure

Question 46

What is dystonia involving the laryngeal muscles called?

Answer 46

Laryngeal (spasmodic dysphonia)

Question 47

What is another name for cervical dystonia?

Answer 47

Spasmodic torticollis

• no specific pathological or neurochemical abnormalities identified for any of the primary focal dystonias

Question 48

Even though primary generalized dystonia is autosomal dominant, why are all people not affected?

Answer 48

It has a 30-40% penetrance rate = therefore, MOST individuals with the mutation may not ever develop the dystonia