What does the suffix -paresis mean?
i.e. Hemiparesis - Weakness on one side of body.
What does the suffix -plegia mean?
i.e. Paraplegia, paralysation of both legs.
What does the root myelo- mean?
Pertaining to the spinal cord, e.g. myelitis (inflammation of the spinal cord).
What does the root Radiculo- mean?
Pertaining to the nerve root, e.g. radiculopathy (damage to the nerve root)
What does the root myo- mean?
Pertaining to muscle.
What is responsible for the initiation of gait?
• Frontol Lobes
• Basal Ganglia
Which four things are responsible for stepping/movement?
• Motor Cortex
• Spinal Cord
What are responsible for posture control?
• Brain Stem
• Vestibular system
• Visual System
• Muscle Stretch Receptors
What is the pattern seen in muscle wasting disease?
• Tends to affect proximal muscles.
• Reflexes preserved.
• Affected muscles may be wasted or hypertrophied.
What is an upper motor neurone?
These are nerves that originate in the motor cortex or brain stem and carry information to the lower motor neurones.
What is a lower motor neurone?
These are nerve cells that arrise from the anterior horn cell or cranial nerve nuclei in the brainstem, to innervate skeletal muscle.
What are the best distinguishing features for identifying whether a lesion is UMN or LMN?
Tone and reflexes.
With an upper motor neurone lesion what would expect from tone?
• Pyramidal weakness -
- Flexor weakness
- Flexor spacicity
- Extensor weakness
What would you expect to occur to reflexes as a result of an UMN lesion?
• Hyper-reflexia as no inhibition.
What would you expect from a LMN lesion in terms of tone and reflexes?
• Both reduced due to dennervation/loss-of pathway.
What are the two ascending sensory tracts of the spinal column and what do they carry?
• Spinothalamic- Pain and Temperature
• Dorsal column- Soft touch, proprioception and vibration
Where do the two sensory ascending tracts desucate?
• Spinothalamic - at level of entry.
• Dorsal column - In the medulla
What are the two motor spinal tracts? What are their major functions?
• Pyramidal tracts- Carry direct signals to motor neurones.
- Corticospinal- Carries 90% of pre-ganglionic motor neurones to somatic origins.
• Extrapyramidal tracts- Responsible for modulation of motor signals
Where do the two motor tracts of the spine dessucate?
• Corticospinal - Dessucate in the medulla.
What is the blood supply of the spinal cord?
• 1 anterior spinal artery and 2 posterior spinal arteries.
What is the implication of their being 1 anterior spinal artery?
• Occlusion of haemarrhoge may result in the loss of the corticospinal and spinothalamic tracts.
What is Cauda Equina syndrome?
• Compression of lumbar and sacral nerve roots (LMN) within cauda equina.
• Requires urgent decompression.
What are the red flag symptoms for Cauda Equina syndrome?
• Urinary retention
• Faecal incontinence
• Saddle Anaesthesia
What are the cerebral signs of an UMN lesion?
• Unilateral, Associated sensory symptoms, Dysphasia, Personality changes, seizures.
What are the brain stem signs of an UMN lesion?
• Diplopia, dysphagia, dysarthria, cranial nerve symptoms, sensory nerve symtpoms.
What are the spinal cord signs of an UMN lesion?
• Bilateral, sexual/bladder/bowel dysfunction, sensory signs.
What are the anterior horn cell signs of a LMN lesion?
• Weakness, wasting, arreflexia.
What are the Neuro-muscular junction signs of a LMN lesion?
• Fatiguable weakness, specific distribution, possible autonomic symptoms.
What are the muscle signs of a LMN lesion?
Wasting, occasional pain, frequently proximal distribution.
What is motor neurone disease?
A disease causing the wasting of the anterior horn cells, resulting in LMN and UMN symptoms.
What is the aetiology of motor neurone disease?
Unknown, but atrophy of the anterior horn cells occurs in all forms and the corticospinal tracts also sclerose.
• Leads to wasting of motor neurones and muscles, cerebral atrophy may also be associated.
What are the UMN signs of motor neurone disease?
• Spastic paraparesis, brisk jaw jerk, dysarthria.
What are the lower motor neurone signs of motor neurone disease?
Weakness, Wasting, Fasiculations
What is Myasthenia Gravis?
Autoimmune disease, where antibodies are produced against nicotinic acetylcholine receptors at neuromuscular junctions.
Results in muscle weakness and fatiguability.
What are the symptoms of Myasthenia Gravis?
• Muscle fatiguability which may affect:
- Limbs paticulary proximal muscles
• Sudden or gradual onset and muscles may suffer intermitently.
What is the 'peek' test?
This is used to assess muscle fatiguability, such as seen in Myasthenia Gravis.
Eyes are closed, sclera can begin to be seen as eyelids weaken.
What investigations can be performed for Myasthenia Gravis?
• Serology - Antibodies
• Neurophysiology - Muscle fatigue assessed by electrical stimulation.
• Edrophonium test.
What are the treatment options for Myasthenia Gravis?
• Acetylcholine esterase inhibitors.
• Immunosupressive drugs.
• Antibody treatment.
• Surgery - Thymus removed, in thymal mediated MG.
What is muscular dystrophy?
A collection of inherited disorders of muscle structure (e.g. Duchennes, Beckers).
Resulting in progressive wasting and weakness.
What is the pathophysiology of muscular dystrophy?
• Genetic problem producing flawed 'dystrophin glycoprotein-complex'
- Responsible for anchoring of muscle fibres.
What are the signs and symptoms of muscular dystrophy?
• Progressive weakness and wasting.
• Proximal > Distal.
• Poor balance, scoliosis, drooping of eye-lids.
What are the investigations for muscular dystrophy?
• Elevated serum Creatinine Kinase (Released by muscle breakdown).
• DNA testing
• Muscle Biopsy
What is the development and symptoms of statin-induced myopathy?
• Asymptomatic rise in creatinine phosphatase, causing myalgia and myositis, eventually muscle breakdown.
• Muscle pain/tenderness
• Proximal muscle weakness
What is polymositis?
• Acquired condition where cytotoxic T-cells destroy muscle fibres.
• Causing proximal weakness, myalgia and increased serum CK.
• Treated with immunosupressants.
What is dermatomyositis?
• Acquired condition where antibodies attack capillaries and arterioles in muscle and skin etc.
• Causes, Proximal weakness, myalgia and characteristic rash and fever.
• Treated with immunosupressants.
What is Inclusion Body Myositis?
• Elderly onset acquired inflammatory pathology.
• Gradual onset of weakness of knee, ankle, finger flexors, and swallowing.
• Poor response to immunosupression.