Module 1 Revision

Primary motor cortex

Somatosensory cortex

If ability to plan, personality and judgement affected, which lobe?

Frontal

Which lobe is associated to visual recognition?

Occipital

Which lobe is associated to speech?

Temporal

What structure inhibits unwanted excessive movements?

Basal ganglia

Which brain structure contributes significantly to directing attention
toward important sensory input?

Thalamus

Which structure is affected if a patient has bad gait or balance?

Cerebellum

Which structure plays the greatest role in refining movements through repetitive practice?

Cerebellum - repetitive practice question

A patient sustains a severe injury to the brainstem. Which function is most immediately life-threatening if disrupted?

Breathing regulation

What are primary (annulospiral) endings?

Afferent and detect change in muscle length and speed of muscle stretch

What are secondary (flower spray) endings?

Afferent and only detect change in muscle length

What are gamma motor neurons?

Efferent, and they affect muscle intrafusal fibres

What are alpha motor neurons?

Efferent and they affect the contractile behaviour of the extrafusal fibres

Monosynaptic v Polysynaptic v Acquired

Mono - 1 synapse in reflex arc between afferent and efferent neurons.

Poly - A sequence of synapses between afferent and efferent

Acquired - Result of learning and practice (cerebral cortex involved)

What is the sequence in the stretch reflex?

1. Stimulus - muscle stretched

2. Muscle spindles detect (primary detect length + rate of stretch, secondary detect mainly length)

3. Sensory afferent neuron carried to spinal cord ventral horn and synapses

4. Motor efferent neuron from ventral horn sent to muscle via alpha and gamma motor neurons

5. Contraction occurs at effector muscle

Type of disorder PD v HD?

PD - neurodegenerative movement disorder

HD - neurodegenerative genetic disorder

Cause - PD v HD

PD - damage to substantia nigra, resutling in dopamine deficiency

HD - Misfolding of huntingtin protein/gene abnormality affecting striatum

Movement characterisation PD v HD

PD - Hypokinetic

HD - Hyperkinetic

Key characteris HD v PD

PD - slow and stiff, TRAP (tremour, rigidity, akinesia/bradykinesia, postural problems)

HD - rapid chorea (jerky movements), impaired coordination, gait problems

Diagnosis PD v HD

PD - clinical assessment, response to dopaminergic therapy

HD - Genetic testing for HTT CAG repeat expansion

Treatment for PD

Levodopa/Carbidopa - dopamine agonists

MAO-B/ COM-T inhibitors

Deep brain stimulation

Treatment for HD?

Symptomatic treatment only

Tetrabenzine for chorea

Psychiatric medication

OT/ Speech therapy

The mechanism of action of tetrabenazine is best described as:

Inhibition of vesicular monoamine transporter (VMAT2)

What is the primary cause of MS?

Autoimmune disease causing demyelination

MS main site and age of onset?

Brain, spinal cord, nervous system, 20-40 years

MS main symptoms

Fatigue, muscle weakness, sensory disturbances, visual problems, balance impairment, spasticity

Disease progression of MS

Usually relapsing remitting initially, may progress over time

MS treatment approaches

Disease-modifying therapies: interferon-beta, glatiramer-beta

Corticosteroids for relapse symptoms

Symptom management

What is clinically isolated syndrome (CIS)?

First episode of MS symptoms, treatment would be disease-modifying therapy (interferon-beta)

What is relapsing-remitting MS? (RRMS)

85% of patients have this, having ‘attacks’ or relapse, with periods of partial or complete recovery

What is secondary progressive MS (SPMS)?

Starts as RRMS, can have active relapses, or just getting progressive worsening

What is primary progressive MS (PPMS)?

Affects 15% of patients - worsening disability from onset of symptoms, without relapses or remissions

What is motor neuron disease (MND)?

A group of diseases in which the motor neurons degenerate and die

Most cases are sporadic, 5-10% genetically linked

MND age of onset

Typically adulthood

MND major symptoms

Progressive muscular weakness, muscle wasting (atrophy), speech and swallowing difficulties, respiratory failure

MND disease progression

Progressive and typically life-shortening

Treatment for MND

Riluzole may slow progression

Multidisciplinary care

What is muscular dystrophy (MD)?

Group of inherited genetic disorders causing degeneration of skeletal muscle fibres

MD age of onset?

Typically childhood

MD disease progression?

Progressive muscle degeneration through life

MD treatments

Corticosteroids

Physio and exercise programs

assistive devices

What is cerebral palsy (CP)?

Damage to the developing brain before, during, or shortly after birth resulting in permanent motor impairment

Major symptoms in CP

Abnormal muscle tone (spasticity), impaired movement, poor coordination, balance difficulties, delayed motor development, speech and feeding difficulties

Progression of CP?

Non-progressive, however functional limitations may change with growth

CP treatment approaches?

Multidisciplinary approach

Baclofen for spasticity

Botulinum toxin injections