Cerebellar Examination (OSCE)

DANISH mnemonic:

 Dysdiadochokinesia

 Ataxia

 Nystagmus

 Intention tremor

 Slurred, staccato speech 

 Hypotonia/heel-shin test

Introduction

1. Greet the patient and introduce yourself 
2. Confirm patient details 
3. Get patient consent ✅
4. Wash hands ✋
5. Check patient is not in any pain 

Inspect the patient for any clinically relevant signs:

 Scars: indicate prior neurosurgery 🧠

 Posture abnormalities: indicate possible truncal ataxia

 Gait abnormalities 🚶

 Speech abnormalities: staccato, slurred speech, often caused by cerebellar disease 

Identify any objects or equipment that may be clinically relevant:

 Prescriptions: indicate recent medications 💊

 Hearing aids: indicate cerebellum pathology associated hearing loss👂

 Walking aids: indicate balance issues (ataxia) ♿

What is ataxia?

 A group of disorders, affecting speech/coordination/balance

 Usually caused by cerebellum damage but also possibly, spinal cord or nerve damage

 Truncal ataxia: due to damaged cerebellar vermis, affects stability of gait 🚶

 Appendicular ataxia: due to damaged cerebellar hemispheres, affects limb movement control 

Gait

Observe the following as the patient walk to the end of the room and back:

 Turning: cerebellar disease makes this difficult 

 Stability: cerebellar pathology causes staggering, unsteady gait, and unilateral cerebellar pathology will cause the patient to veer sideways 

 Stance: midline cerebellar pathology causes a wide-based ataxic gait 🚶

‘Heel to toe’ gait:

 Assess the patient walking from (tandem gait) heel to toe, as this can make it easier to identify subtle ataxia e.g. cerebellar vermis dysfunction 🚶

What is cerebellar degeneration?

 Deterioration of Purkinje cells in cerebellum

 Caused by: alcohol abuse, neurological disease, nutritional deficiencies, paraneoplastic disorders etc. 

 Symptoms: truncal ataxia, nystagmus, wide-based ataxic gait, dysmetria 

Romberg’s Test

Assesses sensory ataxia (loss of proprioceptive or vestibular function):

 A patient requires 2 of the following to balance when standing:

 Vision: visualise position 

 Vestibular function: awareness of position of head (dysfunction caused by Ménière’s disease or neuronitis) 

 Proprioception: awareness of position of body (dysfunction caused by Parkinson’s, hypermobility of joints, B12 deficiency or ageing) 

 Test involves patient closing eyes to assess for deficit in the others, shown by lack of balance 

1. Stand within arms reach to catch them if they fall
2. Ask patient to keep arms by sides and put feet together, then close eyes 👁

 Positive result: patient falls, no correction (due to sensory ataxia) ✅

 Negative result: patient sways but corrects themselves (due to cerebellar disease caused by truncal ataxia) ❌

Speech 

 Ask patient to repeat “British constitution” and “Baby hippopotamus” and assess for:

 Ataxic dysarthria: caused by cerebellar lesions, presents as:

 Slurred speech: like being intoxicated 

 Scanning/staccato speech: words separated into syllables 

Eyes

Nystagmus:

 Involuntary eye movement 👁

1. Assess for nystagmus when eyes are looking straight ahead 
2. Move finger in a ‘H’ shape as patient follows it with eyes 👁
3. Identify multiple nystagmus beats (a few can be normal)

 Identifying presence/absence is sufficient for OSCEs, but it can also be useful to observe the direction and plane of nystagmus and direction of gaze

Dysmetric saccades:

1. Place finger 30cm to side of head 
2. Ask patient to look from your hand to your nose 
3. Repeat for other side of head 👃

 Normal: The patient’s eyes should move quickly 

 Cerebellar lesions: patient’s eyes will go significantly past your finger (dysmetric saccades) 

Impaired smooth pursuit:

 Normal: eyes should move to your finger smoothly 

 Cerebellar lesions: eyes move jerkily 👁

Upper limbs

Finger to nose test for coordination:

1. Place your finger so that that patient must fully stretch to reach it 
2. Ask patient to touch their nose then your finger 👉
3. Ask patient to repeat this action as fast as possible 

 Dysmetria: lack of coordination, meaning patient misses your finger 👉

 Intention tremor: tremor that becomes visible as patient reaches towards your finger 👉

Rebound phenomenon:

1. Close patient’s eyes and stetch their arms out in front if them with palms facing the ceiling 
2. Tell patient to resist as you apply downwards pressure on their forearms, then immediately remove pressure, observing the limb ⬇

 Normal: arm will move upwards then back to original position ⬆

 Cerebellar disease: antagonist muscles do not contract, causing lack of resistance 

Tone:

 Assess the tone of the elbow, wrist and shoulder joint muscles 

1. Hold patient’s hand and elbow ✋
2. Passively control arm movement, moving the elbow, wrist and shoulder
3. Identify tone abnormalities

 Hypotonia: low muscle tone, caused by ipsilateral cerebellar lesion, identified by weakness 

Dysdiadochokinesia:

 The inability to perform rapid, alternating movements, caused by ipsilateral cellular pathology

1. Ask patient to position left palm on top of the right ✋
2. Ask patient to rotate their left hand, so the back of the hand touches the palm of the right ✋
3. Ask patient to rotate hand back so the 2 palms touch
4. Ask patient to repeat steps 1-3 as rapidly as possible 
5. Assess movement
6. Repeat for the other hand ✋

 Cerebellar ataxia: slow/irregular movement

 Ipsilateral cerebellar pathology: dysdiadochokinesia

Lower limbs

Tone:

 Tone can be assessed in the lower limbs (knee, hip, ankle) after the upper limbs although this is unnecessary in OSCEs.

1. Roll one leg at a time to assess the muscle tone
2. Lift each knee off the bed 
3. Assess the movement of the knee, hip and ankle

 Hypotonia: due to ipsilateral cerebellar lesion

Reflexes:

1. Ask patient to hand legs over side of bed 
2. Tap the patellar with the tendon hammer 

 Observe if the ‘knee-jerk’ reflex is present

 Cerebellar disease: pendular (slower) reflexes

Heel to shin test:

1. Ask patient to position left heel on right knee and move it down their shin, then return it to the knee
2. Ask patient to repeat smoothly 🔄
3. Ask patient to repeat with opposite leg 🔄

 Dysmetria: lack of coordination caused by ipsilateral cerebellar pathology

Completion

1. Tell the patient the examination is complete ✅
2. Thank patient 
3. Wash hands ✋
4. Summarise what the examination has revealed 

Summary:

1. Inspect the patient to identify any clinically relevant signs
2. Assess the patient's gait to identify abnormalities
3. Perform Romberg's test to assess sensory ataxia
4. Assess speech for ataxic dysarthria, slurred speech and scanning/staccato speech
5. Inspect eyes for nystagmus,  dysmetric saccades and impaired smooth pursuits
6. Perform upper limb tests: finger to nose coordination test, rebound phenomenon, assess tone of joints,  and assess for dysdiadochokinesia 
7. Perform lower limb tests: assess tone of joints, assess reflexes, perform heel to shin test