Week 2 - E - Pattern recognition in a neurological patient - PD, MS, MND

Question 1

Do lower motor neurons supplying distal muscles or axial muscles lie medially in the grey matter of the spinal cord? Do LMNs supplying flexor or extensor muscles lie anteriorly (ventrally) or posteriorly (dorsally) in the spinal cord?

Answer 1

LMNs supplying axial muscles is medial to the LMNs supplying the distal muscles LMNs supplyinh flexors lie dorsally to ones supplying extensor muscles

Question 2

Pattern recognition helps in lesion localisation and differential diagnosis Accompanying signs assist in the identification of the underlying cause * Tendon reflex alterations and sensory loss * Weakness may be focal or generalized What is the difference between focal and generalized weakness?

Answer 2

A focal neurologic deficit is a problem with nerve, spinal cord, or brain function. It affects a specific location, such as the left side of the face, right arm, or even a small area such as the tongue. Speech, vision, and hearing problems are also considered focal neurological deficits. In contrast, a nonfocal problem is NOT specific to a certain area of the brain. It may include a general loss of consciousness or emotional problem.

Question 3

UMN and LMN lesions have different presenting features How is the weakness distributed in upper and lower motor neuone lesions?

Answer 3

UMN present with pyramidal/corticospinal weakness - this means there is weakness in extensors of the arms and flexors of the legs LMN lesions present with weakness either distally or proximally and can just be generalised

Question 4

Is there any change in the deep tendon reflexes in upper vs lower motor neuone lesions?

Answer 4

The deep tendon reflexes are exaggerated in UMN lesions They are decreased in lower motor neuron lesions

Question 5

UMN vs LMN In which is muscle wasting present?

Answer 5

Muscle wasting is present in lmn lesions

Question 6

Describe features of UMN lesion features? Describe why the features occur

Answer 6

UMN - spastic paralysis - this is because the descending controls arent working and therefore the lmn keeps firing causing the muscle to become spastic but still you have no control hence paralysis INreased muscle tone Hyperreflexia Exaggerated tendon response

Question 7

Describe features of LMN lesion features?

Answer 7

Weakness Atrophy Fasciculations - might have small e.p.s.p that fire but not enough to make an action potential due to lesion so therefore the muscle sort of twitches Decreased tendon reflexes

Question 8

UMN - increased tone, brisk reflexes,pyarmidal weakness What does pyramidal weakness mean?

Answer 8

This means there is weakness in the extensors of the arms and flexors of the legs The pyramidal tract is the corrticospinal tract

Question 9

What are some causes of upper motor neuron lesions?

Answer 9

Stroke Space occupying lesions MS

Question 10

If there is a spinal cord lesion causing signs and symptoms and the lesion occured at the C6 level What UMN signs would be seen above and below the level if it was an upper motor neuron C6 lesion?

Answer 10

ABove the C6 level everything would be normal Below the C6 level there will be pyramidal weakness - weakness in extensors in ams and flexors in legs

Question 11

Describe the corticospinal tract?

Answer 11

Nueones originate in the precentral gyrus in the primary motor area of the frontal lobe Neurones travel down the internal capsule to the medulla where 90% of neurones decussate forming the lateral corticospinal tract The other 10% of neurones decussate at the spinal cord level to form the anterior corticospinal tract

Question 12

WHat other the signs of lower motor neurone pattern symptoms?

Answer 12

Weakness, fasciculations, decreased tone, absent reflexes

Question 13

How does neuromuscular junction problems present which is different to upper and lower motor neurone presentation? Name two neuromuscular junction (NMJ) conditions, the cause and the initial presenting symptoms?

Answer 13

* In NMJ, there is fatiguable weakness & tone usually normal or decreased with normal tendon reflexes * Myasthenia gravis - antibodies to the post-synaptic nicotinic acetylcholine receptors - increasing muscular fatigue starting in extraocular muscles, then bulbar, then face, neck, limb girdle, trunk Lamert-Eaton Myastenic syndrome - antibodies to the pre-synaptic voltage gated calcium channels - gait before eye signs usually, autonomic involvement, weakness usually improves slightly after exercise

Question 14

What can lamert eaton myasthenic syndrome be paraneoplastic from?

Answer 14

Can be paraneoplastic from small cell lung cancer

Question 15

Peripheral nerve involvement can often present symmetrically (often length dependent) or as a mononeuropaty Would peripheral nerve involvement be upper or lower motor neuron? What disease is symmetrical peripheral nerve involvement a frequent complication of?

Answer 15

This would be a lower motor neuron pattern Peripheral nerve involvement is often a frequent complication of diabetes

Question 16

Mononeuropathy as a result of nerve compression (carpal or tarsal tunnel syndrome, ulnar neuropathy, radial neuropathy) Which is carpal tunnel syndrome? What type of distribution is mononeuritis multiplex? What is usually the underlying diseasees?

Answer 16

Carpal tunnel syndrome is where the median nerve is compressed in the carapl tunnel causing weakness and pain distal to the compression It is usually an asymmetrical polyneuropathy Underlying disease is usually vasculitic but can be diabetes also

Question 17

Neuromuscular junction disorders: purely fatiguable motor symptoms Give two neuromuscular junction disorders?

Answer 17

Myasthenia gravis and Lambert eaton myasthenic syndrome

Question 18

What are the autoantibodies produced against in both MG and LEMS?

Answer 18

Myasthenia gravis - autoantibodies against the postsynaptic acetylcholine receptors Lambert eaton myasthenic syndrome - autoantiboides against the pre synaptic calcium channels

Question 19

Are there any sensory nerve loss of function in myasthenia gravis or LEMS?

Answer 19

No sensory loss in either neuromusclar junction disorder

Question 20

LEMS and myasthenia gravis are both associated with weakness Which one does the weakness marginally improve with contraction? Which is associated with small cell lung cancer?

Answer 20

Weakness improves with contractionn in lambert eaton syndrome and is associated with small cell lung cancer in this condition

Question 21

Lower motor neuron conditions can affect specific peripheral nerves WHat nerve, nerve root and therefore muscle would be affected on Shoulder abduction? Elbow extension? Index finger abduction?

Answer 21

Shoulder abduction - Deltoid, axillary nerve - C5 nerve root Elbow extension - Triceps, radial nerve - C7 nerve root Index finger abduction - first dorsal interossei - Ulnar nerve - T1

Question 22

WHat are the autoantibodies produced against in both neuromuscular junction disorders again? What direction does the weakness spread in each disease?

Answer 22

Myasthenia gravis - autoantibodies attack the postsynaptic acetycholine receptors - results in weakness - the weakness starts cranially and moves downwards and is worsened on exercise Lambert eaton myasthenia syndrome - the weakness starts caudally and moves upwards autoantibodies attack the presynaptic calcium channels and weakness improves on exercise

Question 23

Are muscle disorders often proximal or distal? and are they symmetrical or asymmetrical?

Answer 23

Muscle disorders are usually proximal symmetrical disorders eg myositis

Question 24

Which muscle brings about great toe dorsiflexion? What nerve and nerve root is this?

Answer 24

This is the extensor hallus longus Pernoeal nerve - L5 root

Question 25

Deep tendon reflexes for Ankle plantarflexion Knee extension Elbow flexion Elbow extension What muscles, what nerve roots?

Answer 25

Ankle plantarflexion - S1,2 - gastrocnemius and soleus Knee extension - L3,4 - quadriceps femoris Elbow flexion - C5,6 - biceps brachii Elbow extension - C7,8- trcieps brachii

Question 26

Pa#erns of sensory loss • Stocking (and later glove) implies length dependent neuropathy • Sensory level implies a spinal cord lesion What does length dependent neuropathy mean? What does stocking and glove pattern of sensory loss indicate? What is the most common cause of polyneuropathy?

Answer 26

• Diabetes is the most common cause of polyneuropathy - Because the longest nerves are from the back to the feet, these will be affected first, known as stocking as you will be unable to have sensation if pulling on stocking - When the sensory loss reachs the knee, the length of the nerves are roughly the same as the lenght of nerves from neck to fingers and now may start to experience sensory loss in the hands - this is the glove part of length dependent neuropathy

Question 27

What are common causes of mononeuropathy?

Answer 27

Spinal nerve impingement eg spinal stensosi or carpal tunnel syndrome

Question 28

Dissociated sensory loss is a pattern of neurological damage caused by a lesion to a single tract in the spinal cord which involves selective loss of fine touch and proprioception without loss of pain and temperature, or vice versa. What are the two tracts that could potentially be damaged and what sensory innervation does each tract provide?

Answer 28

Dorsal column medial lemnsicus - fine touch, vibration and proprioception SPinothalamic tract - crude touch, temperature and pain

Question 29

What does dissociated sensory loss usually suggest as the cause?

Answer 29

Disscoiated sensory loss usually suggests focal spinal cord or brainstem lesion as the damaging factor - eg hemisection of the spinal cord

Question 30

What condition is characterised by hemisection of the spinal cord?

Answer 30

Brown-Sequard syndrome

Question 31

Motor movements Pyramidal / UMN features – Pyramidal weakness – Spasc,city What are the different ways in which pathology to the basal ganglia can present? (they fall under the category hyperkinetic or hypokinetic disorders) If pathology to the corticospinal tract is known as pyramidal features, what is the pathology to basal ganglia?

Answer 31

Hyperkinetic disorders Myoclonus Chorea Dystonia Hypokinetic Bradykinesia Rigidity This is extrapyramidal features

Question 32

What condition presents with hyperkinetic symptom - chorea? What condition presents with hypokinetic movmeents? due to damage of what part of the basal ganglia?

Answer 32

Chorea - Huntingsons disease (autosomal dominant) due to degenration of striatum (caudate nucleus + putamen)

Hypokinetic - Parkinson’s disease due to degeneration of the substantia nigra

Question 33

Ataxia is a term for a group of disorders that affect co-ordination, balance and speech What part of the brain is affected to cause ataxia?

Answer 33

This would be the cerebellumm

Question 34

Cerebellar gait is broad based and unsteady What type of tremor is seen in cerebellar dysfunction and how is it tested? (explains the name intention tremor)

Answer 34

An intention tremor is seen here The tremor is tested by finger to nose touching and the amplitude of the intention tremor increases as the extremity approaches the end of the deliberate and visual guided movement

Question 35

The ataxia is assessed in the legs by knee to heel testing and tests coordination What is disdiadochokinesis? it is another sign in cerebellar dysfcuntion How is it tested?

Answer 35

Disdiadochokinesis is the medical term for an impaired ability to perform rapid, alternating movements This sign is tested by alternating the back hand and with the palm of the other - this is the rapid alternating hand moevement

Question 36

Nystagmus and dysarthria are additional features of cerebellar disorders What is dysarthria?

Answer 36

Dysarthria is difficulty speaking caused by brain damage or brain changes later in life. dysarthria – difficulty speaking caused by problems controlling the muscles used in speech.

Question 37

The cerebellar signs and symtpoms can be described under the acronym DANISH What does this acrnoym stand for?

Answer 37

• D - disdiadochokinesis - alternating hand test
• A - ataxia (corodination, speech and balance)
• N - Nystagmus
• I - intention tremor - finger nose testing
• S - Speech
• H - Hypotonia

Question 38

The other mnemonic to remember cerebellar features is DDASHING, what do these stand for?

Answer 38

Dysdiadokinesis - impaired rapidly alternating hand movements Dysmetria - past pointing Ataxia Slurred speech (dysarthria) Hypotnoia Intention tremor Nystagmus Gait abnormality - wide based gait

Question 39

Extrapyramidal symptoms / Parkinsonism (motor symptoms) What are the parkinsonism symptoms?

Answer 39

Bradykinesia Hyporeflexia Rigidity Tremor (pill rolling) Shuffling gait

Question 40

What is the reduced degree of facial expression as seen in parkinson known as?

Answer 40

This is known as hypomimia

Question 41

Frontal lobe is very large and has many various signs associated with frontal lobe dysfunction Frontal lobe dysfunction can present with a type of gait known as magnetic gait WHat other condition can present with this?

Answer 41

Normal pressure Hydrocephalus Magnetic gait is when your feet almost refuse to leave the ground, so you really just try and push your feet along the floor

Question 42

What are the main symptoms of normal pressure hydrocephalus?

Answer 42

Wet - incontinent Weird - dementia Wobbly - magnetic gait NPH is called “normal pressure” because despite the excess fluid, cerebrospinal fluid pressure as measured during a spinal tap is often normal.

Question 43

What reflex (primitive) reflex can be seen in people with frontal lobe dysfunction? What type of dysphasia is also seen in people ith frontal lobe dysfucntion?

Answer 43

Grasp reflex is seen Broca’s dysphasia - expressive/motor dysphasia as this is the area of speech production

Question 44

What two symptoms assoicated with epilepsy can be seen in frontal lobe dysfucntion?

Answer 44

Incontinence and seizures - usually continual limb movements ie peddling legs

Question 45

What visua defect is seen in temporal lobe lesions? which part of the optic pathwya is affected? Which language disorder is seen? Episodic memory loss is also common in temporal lobe dysfunction

Answer 45

Homonomyous upper quadrantanopia The temporal optic radiation Language disorder - Wernicke’s dysphasia (receptive or sensory dysphasia)

Question 46

What visual defect is seen in parietal lobe dysfunction? What symptom seen when checking the descending motor pathways is seen? (inability to identify an object with hands without other visual input) - what lesion of the parietal cortex would be affected here

Answer 46

Visual defect seen in parietal lobe dysfunction - homonymous lower quadrantanopia This would be asterognosia, seen when there is damage to the posterior parietal cortex

Question 47

Which type of hyper- or hypokinetic movement disorder is it Hypokinetic? What region fo the brain is responsible for the hyperkinetic and hypokinetic movements?

Answer 47

Hypokinetic - this type of movement disorder is Parkinson’s or Parkinonsim features This would be the basal ganglia - extrapyradimal symptoms

Question 48

Hyperkinetic:

• TREMOR
• TICS
• CHOREA
• MYOCLONUS
• DYSTONIA

Match the to the description

Answer 48

Sustained muscular spasm - dystonia Rhythmic oscillation of agonist&antagonist muscles tremor Rapid, irregular involuntary muscle movements typically involving proximal and distal muscle groups - chorea Sudden fast irregular movements, usually in the same muscle group - tics Sudden fast irregular movements, in same body part - myoclonus

Question 49

Rapid irregular involuntary muscle movements typically involving proximal and distal muscle groups? Sudden fast irregular movements, usually in the same muscle group?

Answer 49

Rapid irregular involuntary muscle movements typically involving proximal and distal muscle groups - chorea Sudden fast irregular movements, usually in the same muscle group - tics

Question 50

Sustained muscular spasm that be focal or generalised? Rhythmic oscillation of agonist&antagonist muscles? What is myoclonus?

Answer 50

Sustained muscular spasm- dystonia Rhythmic oscillation of agonist and antagonist muscles - tremor Myoclonus is the sudden fast irregular movements usually in the same body part

Question 51

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Answer 51

Parkinsons - rigidity, bradykinesia and shuffling gait Also can have hypomimia - lack of facial expression The next diagnostic step would be to carry out some structural imaging for the Parkinsons’ disease The next step in treatment would to be prescribing a dopamine agonist should symptoms cause problems

Question 52

What can be done instead of structural brian imaging to diagnose parkinsons? - usually structural brain imaging is only done if uncertain of the diagnosis What structural imaging can be used in the diagnosis of parkinsons disease?

Answer 52

Dopaminergic agent trial can be carried out - The diagnosis of PD is made clinically and in cases without atypical features no additional diagnostic testing is indicated There should be an improvement in the symptoms of parkinsons when on the dopaminergic agent Structural imaging - SPECT scan or PET with fluorodopa

Question 53

Give examples of the drugs used to treat Parkinsons disease ie what is levodopa? Why is levodopa better than straight dopamine? Name a dopaminne agonist and which receptors it works on

Answer 53

Levodopa is a precursor to dopamine - works by being converted to dopamine after it has crossed the blood brain barrier - dopamine does not cross the blood brain barrier Dopamine agonist - ropinirole and bromocriptine - act directly on the D2 type receptors

Question 54

What other condition is bromocriptine used in? Failure to respond to even large doses of levodopa is usually a strong indicator that the patient does not have idiopathic PD due to 90% of PD patients responding favourably What drug is a weak dopamine atonist that can be used to treat levodopa induced dyskinesias?

Answer 54

Bromcocriptine can be used to treat hyperprolactinaaemia as dopamine is a prolactin antagonist and therefore when this drug acts on the D2-type receptors this will reduce prolactin Amantadine is the drug used to treat levodopa induced dyskinesias

Question 55

What is the purpose of the drug prescribed in Parkinson’s that helps inhibit the aromatic acid decarboxylase? It is often prescribed as a levodopa/drug? combination

Answer 55

Carbidopa - inhibits aromatic acid decarboxylase which would normally breakdown levodopa peripherally and therefore levodopa can cross into the brain

Question 56

What drug can be given as monotherpy in mild Parkinson’s disease? It means the starting dose of levodopa when required is usually lower

Answer 56

This would be the Monoamine oxidase inhibitors eg selegeline

Question 57

Levodopa can alos be broken down by the enzyme catechol-O-methyltransferase (COMT), so COMT inhibitors are usually applied Name a COMT inhibitor?

Answer 57

Etacapone, tolcapone

Question 58

Name the mainstay drug of parkinsons treatment and how it works What drug can be used in conjunction to battle what enzyme peripherally? Name 2 dopamine agonists and what receptos they act on Name a Monamine oxidase B inhibitor Name a catechol-o-methyltransferase (COMT) inhibitor

Answer 58

Levodopa - crosses the blood brain barrier where it is broken down to dopamine Levodopa is often prescribed in conjunction with carbidopa (an inhibitor of aromatic amino acid decarboxylase) - peripheral breakdown of levodopa Dopamine agonists - ropinorle and bromocriptine act on the D2-dopamine receptors in the brain MAO-B inhibitor - selegeline COMT inhibitor - entacapone

Question 59

WHat drug is a weak dopamine agonist used to prevent levodopa induced tremors? Is parkinsons usually symmetrical or asymetricla?

Answer 59

Amtanadine parkinsons is usually asymmetrical

Question 60

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Answer 60

Likely diagnosis is multiple sclerosis Careful neurological assessment and MRI of her brain with galadoinum contrast When diagnosis is confirmed disease modifying therapy is recommended and IV or oral steroids for acute remission

Question 61

Visual compromise, stiffness, and weakness are frequent presenting symptoms in MS. • MS can have lesions on MRI without clinical compromise directly related to those lesions What bands are found in the CSF in MS? Does MS worsen with increasing or lowering temperatures?

Answer 61

Oligoclonal bands are found in the CSF in MS MS worsens with increasing temperatures or fever

Question 62

What is the most common form of motor neuron disease? WHich form of motor neuron disease only affects the lower motor neurons? and which form only affects the upper motor neurons? Motor neuron disease is the degenration of motor neurons leading to weak muscles

Answer 62

Amytrophic lateral sclerosis (ALS) - affects both upper and lower motor neurons and is most common Progressive muscular atrophy - only affects the lower motor neurones Primary lateral sclerosis is the form of MND only affecting the upper motor neurons

Question 63

Usually it is the mix of lower and upper motor neuron abnormalities in the absence of sensory disturbances. that is typical for MND (ALS main one) Cognitive impairment may be part of the presentation (FTD) (fronto-temproal dementia). Ask about cramps, fasciculations, foot drop, family history, behavioural changes What are the upper and lower motor neuron signs seen?

Answer 63

LMN - fasciculations, muscle wasting in myotomes outside a single myotome, foot drop UMN - brisk tendon reflexes, increased tone, loss of dexterity

Question 64

WHat type of dementia is associated with motor neuron disease? What is usually the killer of motor neuron disease?

Answer 64

Frontotemporal dementia is assoicated with MND People usually die from MND due to breathing problems as the lower mtoor neurons going to the respiratory muscls are affected

Question 65

What anti-glutamergic drug is the thought to be the only drug which can help in motor neuron disease?

Answer 65

Riluzole - prolongs life by about 3 months

Question 66

How can MND be distinguished from MS and neuromuscular junction disorders?

Answer 66

MND does not occur with any sensory loss thus distinguishing it from MS or other polyneuropathies MND also never affects eye movements distinguishing it from Myasthenia gravis