Approach to ataxias in adults

Question 1

What is the definition of ataxia?

Answer 1

Loss of full voluntary control of movement

Question 2

What are the midline cerebellar structures critical for?

Answer 2

Motor execution

Rapid and slow eye movements

Balance/lower extremity coordination

Vestibular function

Question 3

What are some of the midline cerebellar structures?

Answer 3

Vermis

Vestibulocerebellum (flocculus and nodulus)

Paravermis/intermediate zone

Fastigial and interposed nuclei

Question 4

What are some of the clinical manifestations of midline cerebellar lesions?

Answer 4

Gait ataxia and imbalance

Truncal ataxia

Dysmetria

Ocular movement changes

Head bobbing

Vertigo

Question 5

Do patients with midline cerebellar lesions have difficulty with walking?

Answer 5

Yes

Especially with tandem walking

Question 6

What is likely to happen to a patient with a midline cerebellar lesion, if you ask them to stand up straight for a short period?

Answer 6

They will likely fall, whether due to vertigo or lower limb ataxia

Question 7

It’s very likely for a patient with a midline cerebellar lesion to have lower limb ataxia – can they have upper limb ataxia as well?

Answer 7

They can, with larger lesions

Especially if the paravermis/intermediate zone is involved

Question 8

How does the truncal ataxia of midline cerebellar lesions be brought out best in patients?

Answer 8

By asking the patient to sit upright in a chair without being able to support themselves with their arms

Question 9

What is dysmetria?

Answer 9

The impaired ability to perform accurate movements during goal-directed tasks because of a faulty estimation of distance

Question 10

T/F dysmetria is almost always only associated with midline cerebellar lesions

Answer 10

F

Can be associated with both midline and hemispheric lesions

Question 11

In dysmetria caused by midline cerebellar lesions, what is the most common clinical sign?

Answer 11

Dysmetria in the lower limbs, with heel-shin test

Question 12

What is ocular dysmetria?

Answer 12

Hypermetric saccadic eye movements

Where the eye overshoots the object, and the eyes rapidly correct their position to focus on the object

Question 13

What does ocular dysmetria suggest?

Answer 13

Strongly suggests cerebellar dysfunction

Question 14

What is the most common ocular manifestation of midline cerebellar lesions?

Answer 14

Saccadic intrusions

Irregular bursts of rapid eye movements

Question 15

What does an up-beating nystagmus indicate?

Answer 15

When present in primary gaze or induced by up gaze is localising to the cerebellar flocculus when cerebellar lesions are suspected

Question 16

Where would a lesion in the cerebellum result in vertigo with nausea and vomiting?

Answer 16

Vestibulocerebellum

Question 17

What other clinical signs are normally found with cerebellar vertigo?

Answer 17

Ocular changes, ie saccadic intrusions, nystagmus etc

Question 18

What are the cerebellar hemispheres concerned with?

Answer 18

Motor planning

Coordination of complex tasks

Question 19

Lesion in one cerebellar hemisphere will produce symptoms in which side of the body?

Answer 19

The ipsilateral side

Cerebellar outputs do not decussate

Question 20

Is dysdiadochokinesis a sign of midline or hemispheric cerebellar lesions?

Answer 20

Hemispheric