Week 8 - cerebellar ataxia and cerebral palsy

Question 1

define cerebellar ataxia

Answer 1

describes a pathology that affects cerebellum and cerebellar pathway.
 There are genetic and non-genetic causes

Question 2

causes of cerebellar ataxia

Answer 2

o Vascular (stroke)
o Infectious disease – HIV or AIDs.
o Metabolic – vitamin B12 or E deficiency.
o Neoplastic – cerebellar tumours.
o Drugs/toxins (alcohol) – Purkinje cells in the cerebellum are particular vulnerable to poisoning.
o Demyelination.

genetic:
o X linked (fragile X) – passed on through the X chromosome.
o Autosomal dominant – means a single copy of the mutated gene is enough to cause the disorder (therefore offspring has a 50% chance of inheriting disorder).
 Spinocerebellar ataxia are associated with autosomal dominant patterns of inheritance.
o Autosomal recessive – two recessive genes are required to cause disorder.
 Friedreich’s ataxia.

Question 3

ethanol in cerebellar ataxia

Answer 3

 Cerebellum is vulnerable to ethanol during development.
 Prenatal exposure may be associated with foetal alcohol spectrum disorder.
 Pathophysiology – Purkinje cells and granule cells are vulnerable to damage by ethanol – depletion of cells.
 Prenatal exposure may be associated with reduced attention and impaired motor skills.
o Adult:
 Acute effects – ataxia appears immediately after excessive alcohol is consumed - gait instability, reduced postural stability and dysarthria.
 Pathophysiology – synaptic dysfunction granule cells and Purkinje cells. Reduction in cerebellar inputs and outputs which disrupt motor and cognitive coordination.
 Chronic effects – atrophy of the superior vermis and reduction in white matter.
 Gait and postural instability – large sway, irregular stepping, limb ataxia and dysarthria, impairments of cognitive skills.

Question 4

spinocerebellar ataxia

Answer 4

o Spinocerebellar ataxia Type 1 (SCA1)
 Inheritance pattern = autosomal dominant.
 Pathophysiology - Causes degeneration and loss of Purkinje and granule cells.
 Symptom onset in 3rd or 4th decade of life.
 Impairments include:
* Ataxic gait
* Dysarthria
* Dysphagia (swallowing difficulty)
* Abnormal eye movements.
* Treatment – no known cure – therefore treatment is to manage symptoms such as pharmacology and allied health neurorehabilitation to maintain or regain function.

Question 5

cerebellar vs sensory ataxia

Answer 5

o Cerebellar ataxia vs sensory ataxia:
 Cerebellar – caused by structural or functional changes to the cerebellum or cerebellum pathways. Results in appearance of ataxic movements.
 Sensory – caused by structural o functional changes to sensory nerves, results in interruption of the sensory feedback therefore impacts ataxic movements.

 Distinguishing sensory vs cerebellar ataxia:
o Romberg’s test – stand with feet together and balance 30 seconds eyes open and then compare with eyes closed.
 Sensory ataxia – patient should be able to stand with eyes open and unstable eyes closed.
 Cerebellar ataxia – unable eyes open and closed.
o Finger nose test – patients index finger to their nose to examiners finger quickly and accurately.
 Sensory ataxia – may demonstrate signs of ataxia when eyes are closed.
 Cerebellar ataxia – may demonstrate signs of ataxia when eyes are open and closed.
o Also – sensory ataxia will not have dysarthria or nystagmus.

Question 6

dysmetria

Answer 6

 Dysmetria
o Involves inaccurate size of movement.
 Hypermetria – overshoots target
 Hypometria – undershoots target.
o Assessed by finger to nose test.
o Abnormal test result – overshoots or undershoots target.
o Functional area of the cerebellum that may be affected – Spinocerebellum.

Question 7

intention tremor

Answer 7

 Intention tremor
o Intention tremor – involuntary, oscillatory, and rhythmic movement. Abnormal activity in agonist and antagonist muscle.
o Assessed – through observation during movement such as the finger nose test.
o Abnormal test result – tremor evidence as approaches the target.
o Functional area of the cerebellum that may be affected – Spinocerebellum.
o Observation of resting tremor – Parkinson’s disease.

Question 8

dysdiodokinesia

Answer 8

 Dysdiadochokinesia
o Difficulty with rapid alternating movements.
o Assessed – through observation of rapid movements with change of direction. E.g., finger tapping, hand tapping, foot tapping, supination and pronation.
o Abnormal test result – slowed reversal of movement, poor rhythm/timing of movement, decreased size of movement.
o Functional area of cerebellum affected – Spinocerebellum.

Question 9

occulo-dysmetria

Answer 9

 Occulo-dysmetria
o Eyes are not able to move accurately towards target.
o Hypometric saccade – eye undershoots target.
o Hypermetric saccade – eye overshoots.
o Assessed – through observation of the eyes as they move from one target to another target.
o Functional area of the cerebellum – vestibulocerebellum.

Question 10

nystgamus

Answer 10

 Nystagmus
o Is an involuntary oscillation of the eye.
o Assessed – through observation of the eyes in primary gaze and during movement.
o Abnormal test result – nystagmus is present during forward gaze or during movement.
o Functional area of the cerebellum affected – vestibulocerebellum.

Question 11

movement decomposition

Answer 11

 Movement decomposition
o Described movement compensation adopted by a person to make movement easier – where movement at one joint is fixed (stopped) whilst moving another joint.
o Assessed – observation of movements that require multiple joints – finger nose test or heel skin slide test.
o Abnormal test result – person may fix a joint and then move the joint in a sequence.
o Functional area of the cerebellum affected – Spinocerebellum.

Question 12

ataxic dysarthria

Answer 12

 Ataxic dysarthria
o Change in the force, timing, range and direction of movement of the articulators that gives very slurred ‘drunk’ sounding presentation.
o Assessed – assessment of articulation and prosody.
o Functional area of the cerebellum that may be affected – Spinocerebellum and Cerebrocerebellum.

Question 13

ataxic gait

Answer 13

 Ataxic gait
o Wide base of support and feet may be angled out.
o Large variability in the walking pattern – variable step length and variable trajectory of the movement.
o Slower walking speed
o Increased risk of falls – also related to postural instability.
o Assessed – observation of walking, timing of walking, and measurement of footstep pattern.
o Abnormal test result- slow, irregular, wide based gait pattern.
o Functional area affected – Spinocerebellum.

Question 14

neural principles of rehab

Answer 14

Neural principles of rehabilitation
 Gaol of therapy = improve function – safe and energy efficient.
 Allied health management:
o Speech and swallowing rehab.
o Interventions to improve balance and gait.
o Interventions to improve coordination – transference to activities of daily living.
 Experience dependent principles
o Salience
o Specificity.
o Transference
o Use and improve it.

Question 15

cerebral palsy

Answer 15

Cerebral palsy
 The most common cause of childhood onset physical disability.
 Defined as an umbrella term for the group of disorders of the development of movement and posture, causing activity limitation that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain.
 The motor disorders of CP are often accompanied by disturbances of sensation, perception, cognition, communication, and behaviour, by epilepsy or secondary musculoskeletal project.
 Neurological impairment is permanent and non-progressive.
 Motor impairment is a defining feature.

Question 16

causes and risk factors

Answer 16

 Prematurity under 37 weeks (risk increases as baby is more premature).
 Low birth weight – less than 1500 g.
 Prenatal exposures (toxic substances).
 Multiple gestations.
 Bacterial and viral infections during pregnancy – rubella.
 Hypoxic brain injury during delivery – small percentage of infants with CP.
 Stroke is the most common cause of CP in babies after one month of age.

Question 17

diagnosis

Answer 17

 From soon after birth to 24 months of age.
 Can be a complex, length process.
 Requires a multidisciplinary approach to assessment.
 A number of assessments are required to build a clinical picture. The following may be used:
o MRI
o Genetic testing
o General movements assessments
o Communication, feeding and swallowing assessments.
 Diagnosis can be hard for parents and family – how we communicate is very important.

Question 18

impairments of cerebral pasly

Answer 18

 Impairments vary substantially depending on location and severity of neurological lesion, but often are described in terms of motor distribution and motor type.

o Motor distribution:
 Quadriplegia/bilateral – all 4 limbs are affected. Face, trunk, and mouth can also be affected.
 Diplegic/bilateral – 2 legs are affected; arms may be affected but to a lesser extent.
 Hemiplegic/unilateral – limbs affected, one side of body.

o Motor type:
 Spastic – 70-80%, most common form, muscles appear stiff and tight, arises from motor cortex damage.
 Dyskinetic – 6%, characterised by involuntary movements, arises from basal ganglia damage.
 Ataxic – 6%, characterised by shaky movements. Affects balance and sense of positioning in space. Arises from cerebellum damage.
 Mixed type – combination damage.

Question 19

spastic cerebal palsy

Answer 19

Spastic cerebral palsy
 Arises from damage to motor cortex.
 Characterized by hypertonia which (cortical motor area).
 Muscle tightness, jerky movements, joint stiffness, and characteristic of spastic CP.
 People may have difficulty with positional change controlling isolation movements needed to perform certain tasks like handling objects or speaking.
 Poor coordination during deliberate movements are consistent, dominant symptoms.

Question 20

ataxic cerebral palsy

Answer 20

 Ataxic CP affects a person’s balance, coordination, and depth perception.
 Ataxic means incoordination or being without order.
 It arises from damage to the cerebellum.
 Movements are often jerky or erratic. People with Ataxic CP have difficulty performing task requiring fine motor skills and uncontrollable shaking during deliberate actions, such as reaching for an object.
 They also have an unsteady gait pattern.
 Muscles are often weak, and this exacerbates other issues.
 People with ataxic CP often experience difficulty moving them yes to where they want ot look, have difficulty swallowing and with speech.

Question 21

dyskinesia motor type

Answer 21

Dyskinesia motor type
 Dyskinetic CP is characterised by fluctuations in muscle tone (dystonia) and abnormal involuntary, uncontrolled movement (athetosis).
 Slowing writhing purposeless movement = athetosis.
 Abrupt jerky movement – chorea.
 ++ involuntary movement
 It arises from damage to the basal ganglia nuclei.
 The lack of controlled movement of upper and lower limbs, face and other parts of their bodies in unpredictable and unexpected ways.
 People with dyskinetic CP movements tend to become more severe in times of emotional stress, and often subside completely during periods of rest.