Week 1 Neurological Symptoms and Pathologies Flashcards

1
Q

Which of the following are lower and upper motor neurons

Subcortical tracts
Internal capsule
Peripheral nerve
Spinal cord
Muscle
Neuromuscular junction
Cortex
Brainstem (decussation in pyramids)
Anterior horns
Ventral roots
Plexi

A
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2
Q

What is the function of the internal capsule?

A

To transport motor information from the cortex to the brainstem and sensory information formt he brainstem to the cortex

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3
Q

What are basal ganglia?

A

The are subcortical nuclei that act as a check on motor signals

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4
Q

What neurons are affected in pyramidal weakness?

A

Upper motor neurons

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5
Q

What is the presentation of pyramidal weakness?

A

Distal muscles weaker than proximal (slow finger/foot taps)

In upper limbs, extensors (e.g. triceps) are weaker than flexors (e.g. biceps)

In lower limbs, the opposite is true; flexors are weaker than extensors

Hint - think of strength as a pyramid with the base proximal and top distal. Also to build a pyramid you need to pick up a block with your biceps and walk it up using your quads.

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6
Q

What do the suffixes paresis and plegia mean?

A

Mild-moderate weakness if often given the suffix -paresis
More severe weakness is given the suffix –plegia

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7
Q

What would weakness with this distribution be called?

A

Monoparesis/-plegia: single limb (can be arm or leg)

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8
Q

What would weakness with this distribution be called?

A

Paraparesis/-plegia: both legs

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9
Q

What would weakness with this distribution be called?

A

Tetraparesis/-plegia: all four limbs (quadriparesis is another term)

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10
Q

What would weakness with this distribution be called?

A

Hemiparesis/-plegia: weakness affecting arm and leg on one side

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11
Q

60 year old female

Awoke with weakness in right hand

On examination
- weakness affecting finger and thumb movements in multiple directions (not conforming to a nerve territory)
mild wrist weakness

Sensation normal

What is going on here?

A

Diagnosis: ischaemic stroke affecting motor hand region (‘hand knob area’)

If there is local motor weakness but sensory is unaffected then you can assume it isn’t a problem with the local nerve. If reflexes aren’t diminished then you can assume it isn’t a lesion in the spinal chord.

By exclusion we are left with a small localised motor cortex lesion/ infarct

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12
Q

65 year old female

Abrupt onset difficulty walking

Reduced power in left ankle movements including dorsiflexion, plantarflexion

Ankle reflexes preserved

Left plantar reflex upgoing

Sensation normal

A

Diagnosis: small haemorrhage in motor region supplying distal lower limb

If there is local motor weakness but sensory is unaffected then you can assume it isn’t a problem with the local nerve. If reflexes aren’t diminished then you can assume it isn’t a lesion in the spinal chord. Upgoing reflex hints at lesion above the segment of the reflex arc (part of spinal chord responsible for reflex)

By exclusion we are left with a small localised motor cortex lesion/ infarct

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13
Q

What parts of the body and in what ways would be affect by a Corona radiata or capsule lesion/ bleed?

A

Tracts travel closely together therefore lesions here affect broad anatomical territory with both motor and sensory effects e.g. hemiparesis +/- hemisensory disturbance

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14
Q

What is important to remeber with the side that effects of a brainstem lesion occur?

A

The lesion is above the decussation of the pyramids.

Hence, crossed signs arise:
- ipsilateral cranial nerve locations
- contralateral signs in limbs

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15
Q

What does a hyperactive stretch reflexe indicate?

A

Hyperactive stretch reflexes are seen when there is interruption of the cortical supply to the lower motor neuron, an “upper motor neuron lesion.” The interruption can be anywhere above the segment of the reflex arc aka anywhere above the part of spinal chord responsible for the reflex?

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16
Q

How does a cervical chord lesion present?

A

Lesion affecting bilateral cord will produce weakness in all four limbs (tetra-)*

Once established, spasticity and brisk reflexes will be present, with upgoing plantars

Other markers of a cord lesion include sensory loss (with a ‘level’) and disturbance to bowel and bladder (sphincter) function

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17
Q

40 year old man

2 weeks progressive walking difficulties

Weak and numb hands with clawing fingers

Difficulty emptying bladder

Tetraparesis, spasticity in all 4 limbs, hyperreflexic

A

Diagnosis: prolapsed intervertebral disc causing cervical myelopathy

Important part: affecting the cervical chord

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18
Q

70 year old man

12 months progressive walking difficulties, accelerated decline last 3 weeks

Difficulty weight bearing; using crutches
Difficulty emptying bladder

Exam: bilateral pyramidal weakness in legs with spastic tone, brisk reflexes, upgoing plantars, sensory disturbance (all modalities)

A

Diagnosis: multilevel degenerative disc disease with prolapsed disc causing compressive myelopathy at T11

Important part: affecting the thoracic chord

19
Q

How does a thoracic chrod lesion present?

A

If this produces weakness it will affect lower limbs, and not upper limbs

Spastic tone, pyramidal weakness, brisk reflexes, upgoing plantars

Will also see
- sensory disturbance (with specific level demonstrating site of lesion in the spine)
- sphincter disturbance

20
Q

How does cauda equina syndrome present?

A

Lesions here can cause bilateral paralysis, sensory loss, LMN signs (e.g. areflexia) and loss of bladder/bowel function

Given where the nerves leave the spinal chord compared to where they leave the vertebre it could present similarly to a lower thoracic spinal chord lesion however the key difference that gives it away as LMN will be diminished reflexes

21
Q

50 year old woman

Acute back pain with radiation down legs (radicular type)

Unable to weight bear
New urinary incontinence, faecal soiling

Exam:
Weakness of hip extensors, loss of ankle reflexes, loss of sensation in L5 and S1 territories, reduced anal tone on rectal exam

Likely diagnoses?

A

Large central disc herniation at L4/5 space causing cauda equina syndrome

22
Q

How does a root lesion present?

What is the word for root compression?

A

Spaces where nerves exit the spinal canal are vulnerable to compression (radiculopathy)

Common cause is prolapsed intervertebral disc

Other causes can include facet joint hypertrophy, spondylolisthesis
- can also include inflammation (radiculitis)

Symptoms include pain which radiates down the nerve (radicular pain), dermatomal sensory loss +/- weakness in the site (LMN signs on exam; areflexia, wasting)

Examination may elicit characteristic pain via provocative manouevers (e.g. straight leg raise), loss of reflexes in affected territory

Similar presentation to cauda equina however will be more localised

23
Q

How would a plexus lesions present?

A

Plexus lesions would typically be unilateral and have LMN lesions characteristics e.g. weakness, sensory loss and reduced reflexes.

However plexus lesions produce a pattern of weakness not conforming to an individual root territory, nor peripheral nerve

24
Q

What is this called and what is it an example of?

A

It is called a Pancoast tumour

Apical lung tumour can invade lower segments of brachial plexus hence an example of a plexus lesion

Patients may present with weakness and wasting of intrinsic hand muscles
- May be first sign of cancer

25
Q

How does a periferal nerve lesion present? What is a another word for it?

A

Lesion affecting individual nerve = mononeuropathy

Signs will reflect loss of function in the region supplied by the specific nerve
Usually sensory +/- motor features
Some nerves are sensory- or motor-only however

Nerves can become damaged by a variety of processes, including compression, inflammation, tumours

26
Q

How does polyneuropahpy present?

Can you give an example?

A

Multiple nerves affected in multiple limbs (+/- cranial nerves)

Various patterns exist, but in general: longest nerves damaged first
Length-dependent pattern arises: ‘glove and stocking’ sensory loss, distal weakness

Reflexes diminished / absent

Chronically (weeks-months) will see wasting, sometimes fasciculations

An example would be Guillian-Barr syndrome

27
Q

What happens with a neuromuscular junction problem?

A

It is caused by the NMJ being ineffecient, either acetylcholine supplies exaust quickly or the few receptors saturate quickly.

This results in fatiguable weakness

28
Q

How does an NMJ problem present? Which muscles does it effect?

A

Fatiguable weakness

Sensation normal

Effects the following areas:

  • Proximal muscles (hip, shoulder, and neck)
  • Ocular muscles
  • Bulbar muscles (dysarthria, disphagia, loss of airway tone)
29
Q

What is this?

50 year old woman
Difficulty keeping eyes open
Intermittent double vision
Slurred speech
Difficulty chewing food and swallowing
Some difficulty standing from a chair

-> Symptoms worse at end of the day (diurnal pattern)

Examination: ptosis, worsening on sustained upgaze; proximal muscle weakness worse on sustained exertion (fatiguability)

A

Myasthenia Gravis

This is a autoimmune dissorder where antibodies are produced for the acetylcholine receptors

Remaining receptors quickly saturate resulting in fatiguable weakness

30
Q

Treatment of Myasthenia Gravis?

A
  1. Pyridostigmine (acetylcholinesterase)
  2. Immunosuppression (steroids, azathioprine, IVIg)
  3. Supportive measures (e.g. feeding tubes, rehabilitation)
  4. In some cases, surgery: association with thymoma (paraneoplastic disorder)
  5. Avoid certain drugs which may worsen the disorder (e.g. gentamicin)
31
Q

Presentation of Myopathy

A

Many diseases exist affecting muscles

As with neuropathy, many different patterns exist

In general however: pattern is of proximal weakness
-> fatiguability is not seen (in contrast to NMJ)
-> reflexes are generally preserved
-> sensation is normal

Other features include characteristic regions of atrophy (or hypertrophy), contractures, pain, dysmorphic features

32
Q

What is this?

66 year old man

Last 2 months: progressive difficulty in walking, now unable to climb stairs, stand from sitting
Also difficulty raising arms to comb hair
Some discomfort in muscles

Exam:
-difficulty standing from sitting: leans on hands
- non-fatiguable weakness in hip and shoulder groups; normal reflexes

Investigations:
-elevated creatine kinase (CK)

  • Muscle biopsy: inflammation and invading lymphoid cells
A

Polymyositis

33
Q

What is polymyositis and what is the treatment?

A

Autoimmune disorder causing muscle inflammation

May sometimes be associated with underlying cancer (paraneoplastic phenomenon)

Treatment:
* Immunosuppression: steroids, azathioprine/methotrexate, IVIg
* Supportive measures: physiotherapy, OT, SLT
* Screen for underlying cancer - and treat if present

33
Q

65 year old man
Gradually progressive symptoms
Began with tripping easily
Last 4 months: slurred speech
Now difficulty using left hand for fine motor tasks (e.g. buttons, laces)

Exam:
* dysarthric speech
* wasting in 1st dorsal interosseous
Weakness in finger movements
* Increased tone in ankle with clonus
Brisk right biceps jerk, absent right knee, brisk right ankle
* Upgoing left plantar
* Sensation normal

A

ALS

Mix of UMN, LMN and bulbar features affecting multiple regions (leg, arms, bulbar)
No sensory features
Gradual, insidious progression over months

-> Characteristic of motor neuron disease
-> most common form (amyotrophic lateral sclerosis)
Degeneration in descending corticospinal pathways, anterior horns and peripheral motor nerves
Incurable and rapidly fatal condition
treatment is supportive

34
Q

What does ALS stand for?

A

amyotrophic lateral sclerosis

a - without
myo - muscle
trophic - nourishment

lateral sclerosis - effects the lateral areas of the spinal chord

35
Q

Can you fill in this table of presentations of different root lesions?

A
36
Q

What arteries supply the spinal chrod and what is the significance of this?

A

Anterior spinal artery (ASA): The primary blood supply to the anterior two-thirds of the spinal cord. The ASA is formed by the vertebral arteries, which originate from the subclavian artery.

Posterior spinal arteries (PSAs): Supply the posterior third of the spinal cord.

This means infarction of one of these areas can occur

37
Q

What is the consequences of anterior spinal infarction?

A

Bilateral weakness - knocked out corticospinal tract

Loss of pain/temperature below the level of the infarct - knocks out spinothalamic tracts

Spared touch, proprioception, vibration

Sphincter disturbance

38
Q

What do the fasciculi do?

What are the consequences of a posterior spinal infarction?

A

Gracile fasciculus
Carries sensory information from the lower half of the body, including the lower limbs, and enters the spinal cord at the lumbar level.
Cuneate fasciculus
Carries sensory information from the upper half of the body, including the upper limbs, trunk, and neck, and enters the spinal cord at the cervical level.
The gracile and cuneate fasciculi are part of the posterior columns, which are made up of the central processes of primary sensory fibers. These fibers transmit information about touch, vibration, and proprioception from the same side of the body

Selective loss of touch, proprioception and vibration

Clinically, sensory ataxia
Falls
Typically worse balance in the dark (and Romberg’s positive)

Unilateral lesions common in MS

Bilateral: tabes dorsalis (Syphilis), B12 deficiency, Friedreich’s ataxia, compression (e.g. tumour)

39
Q

What is a common bacteria that can cause Guillain-Barre syndrome?

A

Campylobacter jejuni

Associated with poultry.

Remember by: Guillain-Barre is a camp drag queen barred from the club so no affects the outside only (periferal de-myelination)

40
Q

What’s going on here?

A patient complains of difficulty walking – his right leg has become weak

He has also noticed something strange
- his right leg feels numb
- yet when having a bath, he couldn’t feel the water temperature with his left (non-weak) leg

Examination:
- right leg: weakness and loss of fine touch, vibration, proprioception
- left leg: motor function intact. Loss of pinprick and temperature sensation

A

Hemichord lesion

Motor control travels down the spinal chord on the same side it innervates

Spinothalamic tract travels up the spinal chord on the contralateral side, pain and temperature

Posterior collumn (The gracile and cuneate fasciculi) travels up on the same side, carries fine touch, vibration and proprioception.

41
Q

Sensory features of a brainstem lesion

A

Features depend on location

Classic findings = crossed sensory loss
- ipsilateral facial numbness
- contralateral limb & body numbness

Additional features reflect involvement of other tracts and nuclei
- gaze palsy
- pyramidal weakness
- impaired swallow

42
Q

What are the signs of a cortico sensory deficit e.g. lesion of the sensory cortex?

A

May lose all modalities in a given region (think homunculous)

May see additional cortical signs (e.g. visual or sensory inattention)

Higher cortical sensations (some sensory processing):
Two-point discrimination
Stereognosis (ability to identify an object’s shape and form by feeling it)
Graphaesthesia (ability to recognize writing or symbols on the skin by touch)

43
Q

Fill in this table

A