Tremor, Dystonia and Chorea (movement disorders)

Question 1

What are the different areas of the brain which can be affected by pathology which result in movement disorders ?

Answer 1

Corticspinal/pyramidal tract can be affected - this results in UMN features such as pyramidal weakness and spasticity

Basal ganglia can be affected, resulting in either hyperkinetic or hypokinetic signs:

Hyperkinetic disorders are also called dyskinesias. There are five forms of dyskinesias which include:

1. Dystonia - Prolonged muscle spasms and abnormal postures
2. Tics - a habitual spasmodic contraction of the muscles, most often in the face.
3. Myoclonus - spasmodic jerky contraction of groups of muscles.
4. Chorea - Fragments of movements flow irregularly from one body segment to another causing a dance-like appearance called Ballismus: if amplitude of these movements is large
5. Tremor - unintentional, rhythmic muscle movement involving to-and-fro movements (oscillations)

Hypokinetic (rigidity and bradykinesia - slow movement) disorders:

Parkinsonism

Parkinson’s disease

Cerebellum - results in ataxia (incoordination)

Question 2

What are the 4 main types of tremors which can be present and describe each of them giving some common causes of each

Answer 2

1. Rest tremor - appears when limb(s) are relaxed and disappears on voluntary movement - think PD for this one
2. Intention tremor - irregular, large amplitude trembling tremor which gets worse at the end of purposeful acts e.g. finger-pointing or using a remote control. This type of tremor is strongly associated with cerebellar damage e.g. MS, stroke
3. Postural tremor - absent at rest, it occurs when person maintains a position against gravity e.g. holding arms outstretched. It may persist during voluntary movement but it does not get worse - causes include benign essential tremor, anxiety, thyrotoxicosis, B-agonists etc
4. Re-emergent tremor - type of postural tremor in Parkinson’s disease represents a rest tremor that re-emerges after a variable delay while maintaining posture, hence “re-emergent tremor”.

Question 3

Define chorea and what the main condition associated with this

Answer 3

• Abnormal involuntary movement which is not rhythmic or repetitive, each movement is brief some examples are facial grimacing, raising shoulders, flexing/extending the fingers
• Fragments of movement flow irregularly from 1 body segment to another causing a dance like appearance

Watch this video - https://www.youtube.com/watch?v=BnBpTsWiIhg

Question 4

Define what a ballismus is

Answer 4

• It is essentially a chorea but it is of large amplitude often affecting proximal limb musculature resulting in jerking, flinging movements of them.
• Usually one side of the body is affected so often termed as hemiballismus
• Due to a lesion of the subthalamic nucleus

Watch this - https://www.youtube.com/watch?v=OeL0bOMghmo

Question 5

Describe what athetosis is

Answer 5

• Slow, involuntary, convoluted, writhing movements of fingers, hands, toes, feet due to lesions affecting the corpus striatum – causes twisting and writhing movements
• Walking becomes difficult - Odd posture and leg movements
• The commonest cause of this is cerebral palsy
• Note think this is another subtype of chorea

Watch this - https://www.youtube.com/watch?v=LmBSZlUZH_M

Question 6

What is myoclonus ?

Answer 6

• Brief involuntary twitching of a muscle or group of muscles
• Sudden muscle contractions are known as positive myoclonus
• Brief lapses of contraction are known as negative myoclonus
• Most commonly occur while falling asleep – hypnic jerk
• Due to CNS disease – multiple sclerosis

Myoclonic seizures – jumps or jolts experienced in a single extremity or even the entire body, uncontrollable jolts similar to an electric shock

• Can affect arm, shoulder, head
• Patient is not conscious during seizures
• Occurs in those with epilepsy

Question 7

What are tics?

Answer 7

• Tics are fast, repetitive muscle movements that result in sudden and difficult to control body jolts or sounds.
• The are common in children and usually resolve

Question 8

Define what a dystonia is

Answer 8

• This is a prolonged muscle contraction causing abnormal posture or repetitive movements
• There are several different forms of dystonia that may affect only one muscle, groups of muscles, or muscles throughout the body.

https://www.youtube.com/watch?v=peb2ow14ANM - this video shows a generalised dystonia

Question 9

The following are the main different types of dystonia, describe the presentation of each:

• Idiopathic generlaised dystonia

Focal dystonias (confined to one part of the body):

• Cervical dystonia/ spasmodic torticollis
• Belpharospasm
• Spasmodic dysphonia/ laryngeal dystonia
• Oromandibular

Answer 9

• Idiopathic generlaised dystonia - not limited to a single part of the body but affects multiple muscle groups throughout the body. Generalized dystonia typically affects muscles in the torso and limbs
• Cervical dystonia/ spasmodic torticollis - most common of the focal dystonias. In cervical dystonia, the muscles in the neck that control the position of the head are affected, causing the head to turn to one side or be pulled forward or backward
• Belpharospasm - involuntary, forcible contraction of the muscles controlling eye blinks (obicularis oculi). The first symptoms may be increased blinking, and usually both eyes are affected. Spasms may cause the eyelids to close completely, causing “functional blindness” even though the eyes are healthy and vision is normal.
• Spasmodic dystonia/ laryngeal dystonia - involves the muscles that control the vocal cords, resulting in strained or breathy speech.
• Oromandibular - affects the muscles of the jaw, lips, and tongue. This dystonia may cause difficulties with opening and closing the jaw, and speech and swallowing can be affected.