Describe the function consequences of damage or injury at the Cerebral Cortex | Damage to motor areas is common after stroke resulting in paralysis of the contralateral upper/lower limbs and facial muscles. Stroke can also result in visual neglect |
Explain the effect on locomotion/body movement when cerebral cortex is damaged or injured | Focal lesions in the Supplementary Motor Area (SMA) result in motor apraxia (the inability to perform purposeful movement even though no paralysis exists. Apraxia can also occur with lesions in premotor/parietal areas. Agnosia is cased by a defect in the ability to recognise sensory stmuli without a defecr in the sense (occurs due to lesions in parietal lobes). Astereognosia involves an inability to recognize objects by touch. Parietal lesions can also lead to visual neglect (not recognising objects in visual field) or denial (viewing the body’s own limbs as belonging to someone else). |
Describe the function consequences of damage or injury at the Basal Ganglia | Basal ganglia contain ~80% of total brain dopamine Parkinson’s disease results from a loss of most of the neurons using dopamine as their neurotransmitter |
Explain the effect on locomotion/body movement when basal ganglia are damaged or injured | Parkinson’s disease is characterised by bradykinesia (slowness), tremor (5-6 Hz), rigidity (resistance to motion), and deficits in postural reactions. Postural reactions - includes deficits in APAs and poor control of pre-programmed reactions |
Describe the function consequences of damage or injury at the Cerebellum | Damage or injury to the cerebellum results in: Ataxia - intention tremor, uncoordinated and inaccurate movements caused by cerebellar lesions |
Explain the effect on locomotion/body movement when cerebellum is damaged or injured | Ataxia deficits include: Delay in the initiation of movement. Inaccuracy in range and direction (dysmetria) and decomposition of movement (moves shoulder first and elbow second). Tremor increases on approaching nose (action) The irregular pattern of alternating movements, such as when pronating and supinating the forearm while flexing and extending at the elbow as rapidly as possible. |
Describe the function consequences of damage or injury at the Spinal Cord | Muscle atrophy - Damage to the spinal cord results in muscle weakness or paralysis Pronounced decrease in muscle size (atrophy) occurs after weeks to months and decreased or absent reflexes occur Disease: amyotrophic lateral sclerosis (ALS). Note: The location of the spinal lesion will produce muscle weakness (or paralysis) and atrophy based on spinal location and somatotopic organisation. |
Explain the effect on locomotion/body movement when spinal cord is damaged or injured | The muscle fibres supplying the degenerating motor neuronbecome denervated and atrophic, resulting in severe muscle weakness. Amyotrophic lateral sclerosis (ALS) leads to progressive death of alpha-motor neurons, resulting in muscle denervation and a loss of voluntary musclecontrol. |