1. Sigismund Wilkey FRCS FRCEM PgC MedED
Weakness &paralysis
Sigismund Wilkey FRCS FRCEM PgC MedED

2. Definition:
Weakness = Loss of strength from a neuromuscular or neurologic disease process, or reduction in the force of voluntary movement (pathology of the motor pathway from cerebral cortex to muscle)
Muscle weakness can be life-threatening if respiratory muscles are involved

3. Objectives – Summary of RCEM Curriculum (Overview of Curriculum CAP 37)
45 minute overview of CAP 37 from a pragmatic ED perspective
Quick Revision of Anatomy & Physiology
Revise features and the differences between UMN, LMN and NMJ lesions
Explore interactively recognised approaches to the structured management of undifferentiated weakness in the ED
Discuss common presentations, such as Stroke and TIA
Classification of Stroke & Prognosis
National Guidelnes for TIAs and strokes
Emergent Investigations
Respiratory & Bulbar muscle weakness
Airway protection and Ventilatory Support
Discuss differential diagnoses and mimics
MDT Approach
Physiology & Neuro anatomy Revision

4. Upper Motor Neurone lesion
A lesion of the cerebral cortex or corticospinal tract
Spasticity of extension in the upper limbs and spasticity of flexion in the lower limbs
Hyperreflexia
Pronator drift
Evoked paraesthesia
Babinski positive
Normal muscle bulk

5. Lower Motor Neurone Lesion from anterior horn to muscle Flaccidity
Hyporeflexia
Fasciculation
Loss of muscle bulk

6. Clinical Characteristics of UMN, LMN, and muscular lesions
Tone
Normal/Decreased
Spastic
Deep Tendon Reflexes
Suppressed/Lost
Exaggerated
Plantar Response
Flexor or none
Extensor (Babinski +VE)
Atrophy
Pronounced (if an axonal pathology)
Slight disuse atrophy
Fasciculations
May be present
Absent
Distribution of weakness
Individual muscles may be involved, or bilaterally innervated muscles may be involved
Groups of muscles affected, pyramidal pattern
(Extensors weaker than flexors in the arms, and flexors weaker than extensors in the legs)

11. Neuromuscular Junction
Presents with slowly progressive or fluctuating signs . It may also present with bulbar palsy or ocular signs
Bulbar palsy refers to a range of different signs and symptoms linked to impairment of function of the cranial nerves IX, X, XI and XII, which occurs due to a lower motor neuron lesion in the medulla oblongata or from lesions of the lower cranial nerves outside the brainstem
Mixed upper and lower motor neurone pattern
Bilateral proximal muscle weakness
Loss of muscle bulk

12. Myotomal distribution of nerve roots peripheral nerves and tendon reflexes
Apps e.g Essential Anatomy 5

13. Structured Approach to weakness
Clarify what patient actually means by the term weakness
What muscle groups are affected
Timing and speed of onset
Associated findings
Exposure to medications, toxins or infectious agents?
Test to identify lower or upper motor neurone lesions or NMJx
Specialised tests (Not really for the ED)

14. History
Differentiate weakness from fatigue (general lack of energy) – ask objective questions
Spatial distribution of weakness
Proximal muscle weakness, tends to be myopathic(direct damage of muscles)
Distal weakness is more likely to be a generalised polyneuropathy
Associated symptoms (e.g cauda equina-like)
Temporal characteristics (compare myasthenia gravis, entrapment neurpoathy or radiculopathy)
Family History
e.g Familial Periodic Paralysis, can be associated with inherited ion chanelopathies,

15. Tools for the classification of stroke and it’s prognosis
Stroke Teams available in most hospitals (Hyperacute stroke Guidelines)
There may be 24 hour Stroke specialist nurse services, coupled with Telemedicine support out of hours
In hours there may be a stroke physician available
Rosier Score should be calculated for all suspected strokes
Loss of consciousness (-1)
Syncope (-1)
New asymmetricalfacial weakness (+1)
Arm weakness (+1)
Leg Weakness (+1)
Speech disturbance (+1)
Visual field defect (+1)
If the score is >= 1 treat as astroke

16. NIHSS Score Done by stroke nurse in Hyperacute sroke units mostly
See proforma
Urgent CT scan within 1 hour
Ensure that plan to assess swallowing and feeding instituted
Manage very high systolic pressures if thrombolysis anticipated
Ischaemic Strokes - Thrombolyse as per local protocol
TIA and non-disabling strokes - Doppler and vasular surgery input
Haemmoragic strokes, reverse anticoagulants if possible

17. Implications of muscular weakness affecting the respiratory and bulbar muscles
Be on high alert, as respiratory failure needs to be anticipated
Call anaesthesia/ITU if capability not available in your ED
Not the ideal candidate for a stroke unit bed
Will need airway support to go for CT scan if needed

18. Airway Protection and Ventilatory support
Warning signs of impending respiratory failures: Early premptive intubation needed
Rising Carbon dioxide
Decreased sensorium
Tachypnoea
Increased work of breathing, with shallow resps
Accessory muscle use

19. Timely Diagnosis and disposition Suggestions
Impending respiratory failure, - prepare for PPV
Sudden onset of focal weakness, is a stroke until proven otherwise
Severe headache with unilateral weakness is an SOL till proven otherwise
Patients with UMN that localise to the spinal cord or CST need urgent imaging (MRI)
If this is combined with sphincter abnormalities – Think Cauda Equina (saddle anaesthesia/paraesthesia), urinary retention, and faecal incontinennce [Beware incomplete lesions)

20. Investigations/Bedside tests
CT or CT angiogram
Urgent MRI
Residual Bladder volumes
CK to check for inflammatory myositis and Medication induced problems (statins)
Pottasium levels in suspected chanelopathies
High index of suspicion for strokes and SOL

21. Multidisciplinary Approach
Stroke team in Hyperacute stroke units
Swallow testing by ENT or other services
Prompt radiological input e.g CT or MRI
Anaesthesia/ITU
Rehabilitation services
In some cases neurolgy

22. Questions