Cerebellar examination

Question 1

Describe DANISH mnemonic for what to cover

Answer 1

Dysdicochokinesis
Ataxia
Nystagmus
Intention tremor
Speech (staccato, slurred)
Hypotonia

Question 2

Cerebellar: general inspection

Answer 2

Clinical signs
-Abnormal posture (truncal ataxia)
-speech abnormalities (slurred staccatto)
-scars
-gait (broad based)

Objects and equipment
-Walking aids (ataxia)
-Hearing aid (acoustic neuroma)
-Prescriptions

Question 3

Gait: how to assess

Answer 3

Assess normal gait
Assess heel toe gait

Question 4

Ataxia

Answer 4

-Involuntary movements which interfere with normal smooth trajectory of movement
-Can be trunkal or appendicular

Question 5

Truncal ataxia

Answer 5

-Proximal musculature involved in gait stability
-midline vermis lesions

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)

Question 6

Appendicular ataxia

Answer 6

-Affects musculature of arms and legs involved in control of limb movement
-Caused by damage to cerebellar hemispherers

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 7

Assess patient’s gait: what is assessed?

Answer 7

Stance: 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).

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

Turning: patients with cerebellar disease will find the turning manoeuvre particularly difficult.

Question 8

Describe cerebellar degeneration

Answer 8

Progressive loss of purkinje cells in cerebellum

Causes;
-Alcohol
-B12
-MS

Progressive loss of Purkinje cells in the cerebellum. It has a wide range of causes including chronic alcohol abuse, nutritional deficiency (typically B12), paraneoplastic disorders and neurological diseases (e.g. multiple sclerosis, spinocerebellar ataxia).

Question 9

What are clinical features of cerebellar degeneration?

Answer 9

Broad-based ataxic gait
Truncal ataxia
Dysmetria (incoordination)
Nystagmus (abnormal eye movements)

Question 10

Describe romberg’s test, what does it test for?

Answer 10

-Assesses for loss of proprioceptive/vestibular function (sensory ataxia)

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 11

What is required to maintain balance?

Answer 11

–> two of vision, proprioception (body position) and vestibular function (head position)

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:

Proprioception: the awareness of one’s body position in space.
Vestibular function: the ability to know one’s head position in space.
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 12

Romberg’s test: interpretation

Answer 12

Causes proprioceptive dysfunction:
-Joint hypermobility (ehler’s danlos)
-B12 deficiency
-parkinson’s disease

Causes vestibular dysfunction:
-Vestibular neuronitis
-meniere’s disease

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). Causes of proprioceptive dysfunction include joint hypermobility (e.g. Ehlers-Danlos syndrome), B12 deficiency, Parkinson’s disease and ageing (known as presbypropria). Causes of vestibular dysfunction include vestibular neuronitis and Ménière’s disease.

Swaying with correction is not a positive result and often occurs in cerebellar disease due to truncal ataxia.

Question 13

How would you assess speech?

Answer 13

Assess speech by asking the patient to repeat the following phrases:

“British constitution”
“Baby hippopotamus”

Question 14

Eyes

Answer 14

Nystagmus
Impaired smooth pursuit
Dysmetric saccades

Question 15

Assessing for dysmmetric saccades

Answer 15

Dysmetric saccades
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.

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 16

Describe impaired smooth pursuit

Answer 16

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 17

Upper limb

Answer 17

-Finger nose test
-Rebound phenomenon
-Tone
-Dysdidochokinesia

Question 18

Finger to nose test abnormalities

Answer 18

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

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 19

Rebound phenomenon abnormalities

Answer 19

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

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

Question 20

Tone abnormalities

Answer 20

Hypotonia can be caused by an ipsilateral cerebellar lesion. However, the ability to detect reduced muscle tone is highly subjective and in many cases, tone can feel ‘normal’ in cerebellar disease. As a result, it is advisable not to put too much weight on this sign or the lack of it.

Question 21

Lower limb

Answer 21

Tone
Reflexes
Heel-shin test

Question 22

Reflexes cerebellar disease

Answer 22

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 23

Describe how you would complete examination

Answer 23

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).

Question 24

Order of cerebellar exam

Answer 24

Inspection
Gait
Romberg’s test
Speech
Eyes
Upper limbs
Lower limbs