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== Background ==
==Background==
*Determine if patient has actual neuromuscular weakness (suggesting CNS dysfunction) or non-neuromuscular weakness.


Determine if pt has actual neuromuscular weakness (suggesting CNS dysfuction) or non-neuromuscular weakness.
==Clinical Features==
===History===
*'''True motor weakness (neuromuscular weakness)? Bilateral or unilateral (distribution of weakness)?'''
**Bilateral weakness:
***Symmetric ascending paralysis? [[Guillain-Barre Syndrome]]
***Weakness involving both central and peripheral nervous system? Inflammatory/Autoimmune or toxic/metabolic
***Discrete sensory level and/or bladder dysfunction? [[Spinal Cord Lesion]]
***Involvement of proximal > distal musculature? Myopathy, Polymyalgia Rheumatica
***Involvement of distal > proximal musculature? Neuropathy
**Unilateral weakness: [[CVA]], [[TIA]]
*'''If non-neuromuscular weakness''' then BROAD differential, obtain:
**[[ECG]], CBC, Chem10, [[LFTs]], blood cultures, [[UA]]/urine culture, drug levels, [[CXR]], Consider [[Head CT]] ([[focal deficit]], [[AMS|altered]], history of cancer, [[anticoagulation]] with minor trauma)
*'''Onset of weakness sudden or gradual?'''
**Sudden suggests vaso-occlusive etiology [[CVA]]/[[TIA]]
**Gradual onset likely non-vascular
*'''Significant event surrounding onset of weakness?'''
**[[Seizure]] prior to weakness? Todd’s paralysis
**Migraine headache? Complicated [[migraine]]
**Sudden onset of severe headache? [[SAH]]
**Trauma? Epidural or [[Subdural Hematoma]]
**Severe migratory neck or chest pain? [[vertebral and carotid artery dissection|Arterial dissection syndromes]]
*'''Temporal pattern to weakness? Fluctuating or fixed weakness?'''
**Weakness with repetitive motions? Neuromuscular junction pathology like [[Myasthenia Gravis]]
*'''Associated symptoms?'''
**[[Headache]]: [[SAH]], epidural/[[SDH]], complicated migraines (young females), not usually stroke/TIA (unless high intracranial pressure)
**[[visual disturbances|Vision changes]]: Posterior circulation [[stroke]], [[Myasthenia Gravis]]
**[[Shortness of breath]]: cardiovascular etiology
**[[Chest pain]] or [[neck pain]]: Acute [[vertebral and carotid artery dissection|carotid/vertebral]]/[[aortic dissection]], [[AMI]]
**[[abdominal pain|Abdominal]] or [[back pain]]:
***with alteration of bowel habits? [[Botulism]], organophosphate poisoning, toxins, [[Guillain-Barre Syndrome]], [[Electrolyte Imbalance]].  
***with lower extremity weakness? [[AAA]] with spinal cord infarction
***[[Back pain]] with unilateral weakness? Herniated disk with nerve impingement
***Bilateral weakness with sensory level s/p trauma? [[spinal cord injury|SCI]], [[Cauda Equina Syndrome]]
**[[Nausea/vomiting]]: sign of [[elevated ICP|↑ ICP]], can lead to [[electrolyte imbalances]]
**Rash: [[Dermatomyositis]]


==Diagnosis==
===Physical Exam===
=== History  ===
''Focus on clarifying if patient has true loss of strength and determining distribution of deficits. Check for trauma, carotid bruits, thyroid enlargement, irregular rhythm, unequal pulses, rashes or ticks.''
#'''True motor weakness (neuromuscular weakness)? Bilateral or unilateral (distribution of weakness)?'''
##Bilateral weakness:
###'''W/symmetric ascending paralysis?''' GBS
###'''W/weakness involving both CN + PNS?''' Inflammatory/Autoimmune or toxic/metabolic
###'''W/discrete sensory level and/or bladder dysfxn?''' Spinal cord lesion
###'''W/involvement of proximal > distal musculature?''' Myopathy
##Unilateral weakness: CVA, TIA
#'''If non-neuromuscular weakness''' then BROAD Ddx obtain:
##ECG, CBC, Chem10, LFTs, blood cx, UA/UCx, drug levels, CXR, Consider Head CT (focal deficit, AMS, h/o CA, anticoagulation w/minor trauma)
#'''Onset of weakness sudden or gradual?'''
##Sudden suggests vaso-occlusive etiology CVA/TIA
##Gradual onset likely non-vascular
#'''Significant event surrounding onset of weakness?'''
##'''SZ prior to weakness?''' Todd’s paralysis
##'''Migraine HA?''' Complicated migraine
##'''Sudden onset of severe HA?''' SAH
##'''Trauma?''' Epidural or SDH
##'''Severe migratory neck or chest pain?''' Arterial dissection syndromes
#'''Temporal pattern to weakness? Fluctuating or fixed weakness?'''
##'''Weakness w/repetitive motions?''' NMJ pathology like MG
#'''Associated Sx?'''
##'''HA:''' SAH, epidural/SDH, complicated migraines (young females), not usually stroke/TIA (unless high ICP)
##'''Vision changes:''' Posterior circulation stroke, MG
##'''SOB:''' CV etiology
##'''CP or neck pain:''' Acute arterial dissection, AMI
##'''Abdominal or back pain:'''
###'''w/alteration of bowel habits?''' Botulism, organophosphate poisoning, toxins, GBS, electrolyte imbalance.  
###'''w/LE weakness?''' AAA with spinal cord infarction
###'''Back pain with unilateral weakness?''' Herniated disk w/nerve impingement
###'''BLE weakness w/sensory level s/p trauma?''' SCI, cauda equina syndrome
##'''N/V:''' sign of ↑ ICP, can lead to electrolyte imbalances
##'''Rash: '''Dermatomyositis<br>


=== Physical Exam  ===
{| class="wikitable"
Focus on clarifying if pt has true loss of strength and determining distribution of deficits. Check for trauma, carotid bruits, thyroid enlargement, irregular rhythm, unequal pulses, rashes or ticks.
| align="center" style="background:#f0f0f0;"|'''Location'''
| align="center" style="background:#f0f0f0;"|'''Weakness'''
| align="center" style="background:#f0f0f0;"|'''Bowel/Bladder'''
| align="center" style="background:#f0f0f0;"|'''Reflexes'''
| align="center" style="background:#f0f0f0;"|'''Sensory'''
| align="center" style="background:#f0f0f0;"|'''Pain'''
|-
| '''Upper motor neuron'''||||||||||
|-
| Brain||Variable||||Increased ||Diminished||No
|-
| Brainstem|| "crossed" findings - ipsilateral cranial nerve weakness and contralateral hemiparesis||||||||
|-
| Cord||Fixed level ||Yes ||Increased ||Diminished||+/-
|-
| '''Lower motor neuron'''||||||||||
|-
| Nerve||Distal > proximal and ascends ||No||Diminished||Nl/parethesias||No
|-
| '''End-plate/muscle'''||||||||||
|-
| Motor end plate||Ocular, bulbar and descends, fatigable ||No||Nl/diminished||Nl/parethesias||No
|-
| Muscle||Proximal > distal ||No||Nl/diminished||Normal||+/-
|}


==== Upper Motor Neuron  ====
==Differential Diagnosis==
{{Weakness DDX}}


*BRAIN
==Evaluation==
**Weakness - variable
===Workup===
**Bowel/Bladder -&nbsp;
'''On all patients:'''
**Reflexes - increased
*CBC (anemia)
**Sens - diminished
*Chem 10 ([[electrolyte disturbance]], [[hypoglycemia]], uremia, cardiac enzymes)  
**Pain - no
*[[ECG]] ([[myocardial ischemia|Ischemia]], [[hypokalemia|hypo]]/[[hyperkalemia]])  
**Asymmetric/unilateral<br>
*BRAINSTEM<br>
**&nbsp;"crossed" findings - ipsilateral cranial nerve weakness and contralateral hemiparesis&nbsp;
*CORD
**Weakness - fixed level
**Bowel/Bladder - YES
**Reflexes - increased
**Sens - diminished
**Pain - +/-
 
==== Lower Motor Neuron  ====
 
*NERVE
**Weakness - distal &gt; proximal and ascends
**Bowel/Bladder - NO
**Reflexes - diminished
**Sens - nl/paresthesias
**Pain - no
 
==== End-Plate/Muscle  ====
 
*MOTOR END PLATE
**Weakness - occular,bulbar and descends, fatigable
**Bowel/Bladder - NO
**Reflexes - nl/diminished
**Sens - nl
**Pain - no
*MUSCLE
**Weakness - proximal &gt; distal
**Bowel/Bladder - NO
**Reflexes - nl/diminished
**Sens - nl
**Pain - +/-
 
== Workup  ==
'''On all pts:'''
#CBC (anemia)
#Chem 10 (electrolyte disturbance,hypoglycemia, uremia)  
#ECG (Ischemia,hypo/hyperkalemia)  


'''Consider:'''
'''Consider:'''
#CK (mypoathies)
*CK (myopathies)
#ESR
*Thyroid studies
#CXR and UA (pt w/infectious sx and elderly)
*ESR
#FVC (if e/o resp compromise, i.e. Myasthenia, GBS)  
*[[CXR]] and [[UA]] (if infectious symptoms or elderly)
#CT head (if focal findings, AMS, h/o cancer, h/o any trauma in pt on anticoagulation)
*FVC (if evidence of respiratory compromise, i.e. Myasthenia, GBS)  
#LP (CNS infection, GBS)
*[[CT head]] (if focal findings, [[altered mental status]], history of cancer, history of any trauma in patient on anticoagulation)
 
*MRI or CT with contrast (if a structural cord lesion is suspected)
== DDX  ==
*[[LP]] (CNS infection, GBS)
 
#'''Neuromuscular weakness''' involves derangement of CNS (UMN), PNS (LMN), the motor endplate, or the muscle:
##'''Can't miss dx:'''
###'''UMN:'''
#### [[CVA (Main)]]
#### [[Intracerebral Hemorrhage (ICH)]]
#### [[Multiple Sclerosis (MS)]]
#### [[Amyotrophic Lateral Sclerosis (ALS)]] (UMN & LMN)
###'''Spinal cord disease:'''
#### Infection ([[Epidural Abscess (Spinal)]])
#### Infarction/ischemia
#### Trauma ([[Spinal Cord Syndromes]])
#### Inflammation ([[Transverse Myelitis]])
#### Tumor
###'''Peripheral nerve disease:'''
#### [[Guillain-Barre Syndrome]]
#### Toxins ([[Ciguatera]])
#### [[Tick Paralysis]]
#### DM neuropathy (non-emergent)
###'''NMJ disease:'''
#### [[Myasthenia Gravis]] crisis
#### [[Botulism]]
#### [[Organophosphate Toxicity]]
#### [[Lambert-Eaton Myasthenic Syndrome]]
###'''Muscle disease:'''
#### [[Rhabdomyolysis]]
#### Dermatomyositis
#### Polymyositis
#### Alcoholic myopathy
 
#'''Non-neuromuscular weakness''' can be infectious, cardiovascular, metabolic, toxicologic:
##'''Can't miss dx:'''
### [[Acute Coronary Syndrome (Main)]]
### Arrhythmia/[[Syncope]]
### severe infection/[[Sepsis (Main)]]
### [[Hypoglycemia]]
### Periodic paralysis (electrolyte disturbance, K, Mg, Ca)
### Respiratory failure
##'''Emergent Dx:'''
### Symptomatic [[Anemia]]
### Severe dehydration
### [[Hypothyroidism]]
### Polypharmacy
### Malignancy
 
==Treatment==


=== Intubation Indications ===
==Management==
===[[Intubation]] Indications===
*Severe fatigue
*Inability to protect airway
*Rapidly increasing PaCO2
*[[Hypoxemia]] despite O2
*FVC <12 mL/kg
*Neg Insp Force <20 cm H2O


#Severe fatigue
==Disposition==
#Inability protect airway
*Depends on process
#Rapidly increasing PaCO2
**If normal initial workup, make sure has no respiratory compromise
#Hypoxemia despite O2
#FVC &lt;12 mL/kg
#Neg Insp Force &lt;20 cm H2O


== Source  ==
==See Also==


8/15/13 adapted from Rosen, Tintinalli, Intro to Clincal EM, Lampe, Birnbaumer, Donaldson
==External Links==


[[Category:Neuro]]
==References==
<references/>
[[Category:Neurology]]
[[Category:Symptoms]]

Latest revision as of 20:00, 15 September 2022

Background

  • Determine if patient has actual neuromuscular weakness (suggesting CNS dysfunction) or non-neuromuscular weakness.

Clinical Features

History

Physical Exam

Focus on clarifying if patient has true loss of strength and determining distribution of deficits. Check for trauma, carotid bruits, thyroid enlargement, irregular rhythm, unequal pulses, rashes or ticks.

Location Weakness Bowel/Bladder Reflexes Sensory Pain
Upper motor neuron
Brain Variable Increased Diminished No
Brainstem "crossed" findings - ipsilateral cranial nerve weakness and contralateral hemiparesis
Cord Fixed level Yes Increased Diminished +/-
Lower motor neuron
Nerve Distal > proximal and ascends No Diminished Nl/parethesias No
End-plate/muscle
Motor end plate Ocular, bulbar and descends, fatigable No Nl/diminished Nl/parethesias No
Muscle Proximal > distal No Nl/diminished Normal +/-

Differential Diagnosis

Weakness

Evaluation

Workup

On all patients:

Consider:

  • CK (myopathies)
  • Thyroid studies
  • ESR
  • CXR and UA (if infectious symptoms or elderly)
  • FVC (if evidence of respiratory compromise, i.e. Myasthenia, GBS)
  • CT head (if focal findings, altered mental status, history of cancer, history of any trauma in patient on anticoagulation)
  • MRI or CT with contrast (if a structural cord lesion is suspected)
  • LP (CNS infection, GBS)

Management

Intubation Indications

  • Severe fatigue
  • Inability to protect airway
  • Rapidly increasing PaCO2
  • Hypoxemia despite O2
  • FVC <12 mL/kg
  • Neg Insp Force <20 cm H2O

Disposition

  • Depends on process
    • If normal initial workup, make sure has no respiratory compromise

See Also

External Links

References