Movement Disorder Tutorial

Question 1

What are the signs of an upper motor neurone lesion?

Answer 1

1. Tone increased spastic
2. Clonus present
3. Power weakness
4. Reflexes brisk
5. Extensor plantar responses, no wasting and no fasciculations.

Question 2

What is the power weakness distribution in UMNL?

Answer 2

pyramidal distribution flexors stronger than extensors UL and extensors stronger than flexors in LL

Question 3

Why are reflexes exgggaertaed/brisk. in UMNL?

Answer 3

Inability to activate muscles, decrease level of inhibition that a arrive at ventral horn of motor neurone, so reflexes are exaggerated or brisk

Question 4

What are the signs of an lower motor neurone lesion?

Answer 4

1. Tone flaccid
2. Power weakness
3. no clonus
4. reflexes reduced or absent
5. flexor plantar response
6. wasting may be present
7. fasciculations may be present.

Question 5

What is the power weakness distribution in LMNL?

Answer 5

distal weaker than proximal

Question 6

Is it an isolated lesion if both UMN and LMN are affected?

Answer 6

NO

Question 7

Which pathways are affected?

Answer 7

Pyramidal tracts (these are the corticospinal and corticobulbar tracts) providing voluntary motor commands to limbs/trunk and head/neck respectively

Question 8

Why are abdominal reflexes (superficial reflexes) absent while the other reflexes (deep tendon reflexes) are brisk?

Answer 8

• This is the hallmark of a pure corticospinal tract lesio
• Stroking the skin of the abdomen causes the abdominal wall muscles to contract, sometimes pulling theumbilicustowards the stimulus
• These reflexcontractions are often absent inupper motor neurone disorders.

Question 9

What is a fasciculation? What is its significance?

Answer 9

• A fasciculation is an involuntary and abnormal firing of a single motor neuron and all its innervated muscle fibres
• They are visible to the eye