Cerebellar Examination Flashcards
What does DANISH stand for?
The mnemonic DANISH is a helpful way of remembering the important points to cover in a cerebellar examination:
Dysdiadochokinesia
Ataxia (gait and posture)
Nystagmus
Intention tremor
Slurred, staccato speech
Hypotonia/heel-shin test
What may an abnormal posture indicate?
Abnormal posture: may indicate the presence of truncal ataxia.
What is slurred staccato?
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.
Slurred staccato speech is typical of cerebellar disease.
What is the difference between truncal and appendicular ataxia?
Ataxia
Ataxia is a neurological sign consisting of involuntary movements with an irregular oscillatory quality which interfere with the normal smooth trajectory of movement. Ataxia can be truncal (affecting the trunk) or appendicular (affecting the limbs):
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).
What does a broad based ataxic gait suggest?
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).
What does a staggering, slow and unsteady gait suggest?
A staggering, slow and unsteady gait is typical of cerebellar pathology. In unilateral cerebellar disease, patients will veer towards the side of the lesion.
A patient with abnormal gait related to cerebellar disease may also have difficulty doing what?
Turning: patients with cerebellar disease will find the turning manoeuvre particularly difficult.
What is cerebellar vermis dysfunction caused by and how is it tested?
Tandem gait is particularly sensitive at identifying dysfunction of the cerebellar vermis (e.g. alcohol-induced cerebellar degeneration).
Where does cerebellar dgeneration take place?
List 4 causes?
List 4 classical signs?
Cerebellar degeneration
Cerebellar degeneration involves the 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).
Typical clinical features include:
Broad-based ataxic gait
Truncal ataxia
Dysmetria (incoordination)
Nystagmus (abnormal eye movements)
Which test is used to assess for loss of proprioceptive or vestibular function (known as 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).
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.
During Rombergs test the patient falls without correction, interpet this result?
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.
How may ataxic dysarthria present?
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.
What is nystagmus?
Nystagmus
Nystagmus involves repetitive, involuntary oscillation of the eyes and can be either physiological (i.e. benign) or associated with cerebellar pathology.
What is the difference between dysmetric saccades vs impaired smooth pursuit?
Dysmetric saccades
- Position your hand approximately 30cm to the side of your head.
- 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.
Impaired smooth pursuit
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).
What is dysmetria?
What is intention tremor?
What are these a sign of?
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.
The presence of dysmetria and intention tremor is suggestive of ipsilateral cerebellar pathology.
