Cerebellar Examination

Question 1

What does the mnemonic DANISH mean in relation to a cerebellar exam?

Answer 1

● Dysdiadochokinesia
● Ataxia (gait and posture)
● Nystagmus
● Intention tremor
● Slurred, staccato speech
● Hypotonia/heel-shin test

Question 2

What position should the patient be in before commencing with a cerebellar exam?

Answer 2

● Ask the patient to sit on a chair, approximately one arm’s length away.

Question 3

What clinical signs may be observed during the general inspection section of a cerebellar exam?

Answer 3

● Abnormal posture
● Speech abnormalities
● Scars
● GAIT abnormalities

Question 4

What objects or equipment may be observed during the general inspection section of a cerebellar exam?

Answer 4

● Walking aids
● Hearing aids
● Prescriptions

Question 5

What is the difference between truncal ataxia and appendicular ataxia?

Answer 5

● Truncal ataxia - affects proximal musculature that is involved in gait stability. This form of ataxia is caused by damage to the cerebellar vermis and associated pathways (i.e. midline cerebellar lesions).
● Appendicular ataxia - affects musculature of the arms and legs involved in the control of limb movement. This form of ataxia is caused by damage to the cerebellar hemispheres (i.e. lateral cerebellar lesions).

Question 6

Describe how you would assess a patients gait during a cerebellar exam?

Answer 6

● Ask the patient to walk to the end of the examination room and then turn and walk back whilst you observe their gait paying attention to stance, stability and turning.

● Ask the patient to walk to the end of the examination room and back with their heels to their toes (known as ‘tandem gait’). Heel-to-toe walking exacerbates underlying unsteadiness making it easier to identify more subtle ataxia.

*Patients with cerebellar disease are at an increased risk of falls so make sure to remain close to the patient during the assessment so that you are able to intervene if required.

Question 7

When assessing gait, what may a broad ataxic gait be suggestive of when performing a cerebellar exam?

Answer 7

● A broad-based ataxic gait is typically associated with midline cerebellar pathology (e.g. a lesion in multiple sclerosis or degeneration of the cerebellar vermis secondary to chronic alcohol excess).

Question 8

What may instability and staggering be suggestive of when assessing gait during a cerebellar exam?

Answer 8

● A staggering, slow and unsteady gait is typical of cerebellar pathology. In unilateral cerebellar disease, patients will veer towards the side of the lesion.

Question 9

What may you note about turning during gait assessment in patients with cerebellar disease?

Answer 9

● Patients with cerebellar disease will find the turning manoeuvre particularly difficult.

Question 10

Why is tandem gait (heel-to-toe) also used alongside normal gait assessment in a cerebellar exam?

Answer 10

● Tandem gait is particularly sensitive at identifying dysfunction of the cerebellar vermis (e.g. alcohol-induced cerebellar degeneration).

Question 11

What is Romberg’s test?

Answer 11

● Romberg’s test is used to assess for loss of proprioceptive or vestibular function (known as sensory ataxia).
● The test does not assess cerebellar function and instead is used to quickly screen for evidence of sensory ataxia (i.e. non-cerebellar causes of balance issues).

Question 12

Why does Romberg’s test work?

Answer 12

● Romberg’s test is based on the premise that a patient requires at least two of the following three senses to maintain balance whilst standing:

1. Proprioception: the awareness of one’s body position in space.
2. Vestibular function: the ability to know one’s head position in space.
3. Vision: the ability to see one’s position in space.

● Romberg’s test involves removing the sense of vision by asking the patient to close their eyes. As a result, if the patient has a deficit in proprioception or vestibular function they will struggle to remain standing without visual input.

Question 13

Describe how you would perform Romberg’s test during a cerebellar exam?

Answer 13

1. Position yourself within arms reach of the patient to allow you to intervene should they begin to fall.
2. Ask the patient to put their feet together and keep their arms by their sides (be aware that patients with truncal ataxia may struggle to do this, however, this type of unsteadiness is not the same as a positive Romberg’s sign).
3. Ask the patient to close their eyes.

Question 14

What would a positive Romberg’s test result be and what would it indicate?

Answer 14

● Falling without correction is abnormal and referred to as a positive Romberg’s sign. This indicates unsteadiness is due to sensory ataxia (i.e. a deficit of proprioceptive or vestibular function, rather than cerebellar function).
● Swaying with correction is not a positive result and often occurs in cerebellar disease due to truncal ataxia.

Question 15

How would you assess speech during a cerebellar exam?

Answer 15

● Ask the patient to repeat the two phrases:
● British constitution
● Baby hippopotamus

Question 16

How may a cerebellar lesion affect speech?

Answer 16

● Cerebellar lesions can cause ataxic dysarthria which can present in a number of ways:

● Scanning speech (also known as staccato speech): words are broken down into separate syllables, often separated by pauses and spoken with varying volume.
● Slurred speech: patients are often mistaken for being intoxicated as a result.

● Scanning and slurred speech often occur in combination (often referred to as “slurred staccato speech”).

Question 17

What is nystagmus and what is the relevance to the cerebellum?

Answer 17

● Nystagmus involves repetitive, involuntary oscillation of the eyes and can be either physiological (i.e. benign) or associated with cerebellar pathology.

Question 18

Describe how you would assess for nystagmus during a cerebellar exam?

Answer 18

1. Ask the patient to look straight ahead and examine the eyes in the primary position. Look for any abnormal movement such as nystagmus.
2. Ask the patient to keep their head still and follow your finger (or another visual target) with their eyes.
3. Move your finger throughout the various axes of vision in a ‘H’ pattern.
4. Look for multiple beats of nystagmus (a few beats at the extremes of gaze can be a normal variant and is termed physiological nystagmus).

Question 19

Explain how you would describe nystagmus if there is presence in a patient?

Answer 19

● Direction of nystagmus: most nystagmus has a fast phase and a slow phase (termed “jerk” nystagmus). By convention, the direction of the nystagmus is defined by the direction of the fast phase. In cerebellar lesions, the direction is towards the side of the lesion.
● Direction of gaze: note if nystagmus is present on horizontal or vertical gaze.
● Plane of nystagmus: note if nystagmus beats in a horizontal or vertical plane.

Question 20

Describe how you would perform a dysmetric saccades assessment?

Answer 20

1. Position your hand approximately 30cm to the side of your head.
2. Ask the patient to look at your hand, then back to your nose. Repeat this assessment on both sides.

Question 21

What is a dysmetric saccades assessment used for in a cerebellar exam?

Answer 21

● The movement of the patient’s eyes should be quick and accurate. In cerebellar lesions, there will often be overshoot (i.e. the eyes will go too far past the target, then correct themselves back to the target).
● This overshoot and subsequent correction are known as dysmetric saccades.

Question 22

What is impaired smooth pursuit?

Answer 22

● When the patient is tracking your finger, the eyes should move smoothly (known as ‘smooth pursuit’). In cerebellar lesions, pursuit can be “jerky” or “saccadic”( i.e. made up of lots of small movements).

Question 23

What assessments should be performed on the upper limb during a cerebellar exam?

Answer 23

● Finger-to-nose test
● Rebound phenomenon assessment
● Tone
● Dysdiadochokinesia

Question 24

Describe how you would perform a finger-to-nose assessment during a cerebellar exam?

Answer 24

1. Position your finger so that the patient has to fully outstretch their arm to reach it.
2. Ask the patient to touch their nose with the tip of their index finger and then touch your fingertip.
3. Ask the patient to continue to do this finger to nose motion as fast as they are able to.

Question 25

What is dysmetria?

Answer 25

● Dysmetria: refers to a lack of coordination of movement. Clinically this results in the patient missing the target by over/undershooting.

Question 26

What is an intention tremor?

Answer 26

● Intention tremor: a broad, coarse, low-frequency tremor that develops as a limb reaches the endpoint of a deliberate movement. Clinically this results in a tremor that becomes apparent as the patient’s finger approaches yours. Be careful not to mistake an action tremor (which occurs throughout the movement) for an intention tremor.

Question 27

What would the presence of dysmetria and an intention tremor be suggestive of when conducting a cerebellar exam?

Answer 27

● The presence of dysmetria and intention tremor is suggestive of ipsilateral cerebellar pathology.

Question 28

What is rebound phenomenon?

Answer 28

● Rebound phenomenon is a reflex that occurs when a patient attempts to move a limb against resistance that has been suddenly removed.

Question 29

Describe how you would assess for rebound phenomenon during a cerebellar exam?

Answer 29

1. Ask the patient to close their eyes and position their arms outstretched in front of them. 2. Explain to the patient that you are going to apply some downward resistance on each arm and that they should try to maintain the current position of their arms as you apply that resistance. 3. Push downwards on one of the patient’s forearms and then immediately remove the resistance. 4. Observe the movement of the limb being assessed.

Question 30

What would a normal observation be when assessing rebound phenomenon during a cerebellar exam?

Answer 30

● In healthy individuals, when the resistance is removed the limb will usually move a short distance upwards (i.e. the direction the patient was pushing towards to maintain limb position) before antagonist muscles contract and move the limb back to the original position. ● This is the normal reflex that results in rebound phenomenon.

Question 31

What would exaggerated rebound phenomenon be suggestive of when performing a cerebellar exam?

Answer 31

● An exaggerated version of rebound phenomenon is suggestive of spasticity (e.g. stroke affecting the cerebrum).

Question 32

What would a complete absence of the rebound phenomenon be suggestive of when performing a cerebellar exam?

Answer 32

● A complete absence of the phenomenon, caused by a failure of the antagonist muscles to contract, is suggestive of cerebellar disease.

Question 33

Describe how you would assess the upper limb for tone during a cerebellar exam?

Answer 33

1. Support the patient’s arm by holding their hand and elbow. 2. Ask the patient to relax and allow you to fully control the movement of their arm. 3. Move the muscle groups of the shoulder (circumduction), elbow (flexion/extension) and wrist (circumduction) through their full range of movements. 4. Feel for abnormalities of tone as you assess each joint (e.g. hypotonia).

Question 34

What may hypertonia suggest during a cerebellar exam?

Answer 34

● Hypotonia can be caused by an ipsilateral cerebellar lesion.

Question 35

What is dysdiadochokinesia?

Answer 35

● Dysdiadochokinesia is a term that describes the inability to perform rapid, alternating movements, which is a feature of ipsilateral cerebellar pathology.

Question 36

Describe how you would perform a dysdiadochokinesia assessment?

Answer 36

1. Ask the patient to place their left palm on top of their right palm. 2. Then ask them to turn over their left hand and touch the back of it onto their right palm. 3. Now ask them to return their left hand to the original position (left palm on right palm). 4. Ask the patient to now repeat this sequence of movements as fast as they are able until you tell them to stop. It is often useful to demonstrate the sequence of movements to the patient to aid understanding. 5. Observe the speed and fluency by which the patient is able to carry out this sequence of rapidly alternating movements. 6. Repeat the assessment with the other hand.

Question 37

How may a patient with cerebellar disease perform during a dysdiadochokinesia assessment?

Answer 37

● Patients with cerebellar ataxia may struggle to carry out this task, with their movements appearing slow and irregular. ● The presence of dysdiadochokinesia suggests ipsilateral cerebellar pathology.

Question 38

What assessments should be performed on the lower limb during a cerebellar exam?

Answer 38

● Tone ● Reflexes ● Heel-to-shin test

Question 39

Describe how you would assess tone in the lower limbs during a cerebellar exam?

Answer 39

1. With the patient lying on the examination couch, roll each leg to assess tone in the muscles responsible for the rotation of the hip. 2. Lift each knee briskly off the bed (warning the patient first) and observe the movement of the leg. In patients with normal tone, the knee should rise whilst the heel remains in contact with the bed (the heel will typically lift off the bed if there is increased tone).

Question 40

Describe how you would assess reflexes of the lower limb during a cerebellar exam?

Answer 40

1. Remove the weight from the patient’s lower limb by either supporting it or asking the patient to hang their legs over the side of the bed. Ensure the patient’s lower limb is completely relaxed before assessing the deep tendon reflex. 2. Tap the patellar tendon with the tendon hammer (making sure to hold the tendon hammer handle at its end to allow gravity to aid a good swing). 3. If a reflex appears absent make sure the patient is fully relaxed and then perform a reinforcement manoeuvre.

Question 41

How would a reflex change if a patient has cerebellar disease?

Answer 41

● In cerebellar disease, reflexes are described as ‘pendular’, which means less brisk and slower in their rise and fall. ● However, similar to reduced tone, this sign is very subjective and often reflexes appear to be ‘normal’ in cerebellar disease.

Question 42

Describe how you would get a patient to perform a heel-to-shin test during a cerebellar exam?

Answer 42

1. Ask the patient to place their left heel on their right knee and then run it down their shin in a straight line. 2. Then ask them to return their left heel to the starting position over the right knee. 3. Now ask them to repeat this sequence of movements in a smooth motion until you tell them to stop. 4. Repeat the assessment with the right heel on the left leg.

Question 43

What further assessments or investigations could be performed after a cerebellar exam has concluded?

Answer 43

● Full neurological examination including the cranial nerves and the upper and lower limbs. ● Neuroimaging (e.g. MRI head): if there are concerns about space-occupying lesions or demyelination. ● Formal hearing assessment (including pure tone audiometry): if there are concerns about vestibulocochlear nerve function (e.g. acoustic neuroma).