Weakness: Difference between revisions

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== Approach  ==
==Background==


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


== DDX  ==
==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
**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]]


#'''Neuromuscular weakness''' involves derangement of CNS (UMN), PNS (LMN), the motor endplate, or the muscle:
===Physical Exam===
##'''Can't miss dx:'''
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.  
###'''UMN:''' [[CVA]], [[Intracerebral Hemorrhage (ICH)]], [[Multiple 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:''' dermatomyositis, polymyositis, alcoholic myopathy, [[Rhabdomyolysis]].


#'''Non-neuromuscular weakness''' can be infectious, cardiovascular, metabolic, toxicologic:
{| class="wikitable"
##'''Can't miss dx:'''
| align="center" style="background:#f0f0f0;"|'''Location'''
### [[ACS]]/[[MI]]
| align="center" style="background:#f0f0f0;"|'''Weakness'''
### Arrhythmia/[[Syncope]]
| align="center" style="background:#f0f0f0;"|'''Bowel/Bladder'''
### severe infection/[[Sepsis]]
| align="center" style="background:#f0f0f0;"|'''Reflexes'''
### [[Hypoglycemia]]
| align="center" style="background:#f0f0f0;"|'''Sensory'''
### Periodic paralysis (electrolyte disturbance, K, Mg, Ca)
| align="center" style="background:#f0f0f0;"|'''Pain'''
### Respiratory failure
|-
##'''Emergent Dx:'''
| '''Upper motor neuron'''||||||||||
### Symptomatic [[Anemia]]
|-
### Severe dehydration
| Brain||Variable||||Increased ||Diminished||No
### [[Hypothyroidism]]
|-
### Polypharmacy
| Brainstem|| "crossed" findings - ipsilateral cranial nerve weakness and contralateral hemiparesis||||||||
### Malignancy
|-
| 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||+/-
|}


== Workup ==
==Differential Diagnosis==
'''On all pts:'''
{{Weakness DDX}}
#CBC (anemia)
 
#Chem 10 (electrolyte disturbance,hypoglycemia, uremia)  
==Evaluation==
#ECG (Ischemia,hypo/hyperkalemia)  
===Workup===
'''On all patients:'''
*CBC (anemia)
*Chem 10 ([[electrolyte disturbance]], [[hypoglycemia]], uremia)  
*[[ECG]] ([[myocardial ischemia|Ischemia]], [[hypokalemia|hypo]]/[[hyperkalemia]])  


'''Consider:'''
'''Consider:'''
#CK (mypoathies)
*CK (mypoathies)
#ESR
*ESR
#CXR and UA (pt w/infectious sx and elderly)
*[[CXR]] and [[UA]] (if infectious symptoms or elderly)
#FVC (if e/o resp compromise, i.e. Myasthenia, GBS)  
*FVC (if evidence of respiratory compromise, i.e. Myasthenia, GBS)  
#CT head (if focal findings, AMS, h/o cancer, h/o any trauma in pt on anticoagulation)
*[[CT head]] (if focal findings, [[altered mental status]], history of cancer, history of any trauma in patient on anticoagulation)
#LP (CNS infection, GBS)
*[[LP]] (CNS infection, GBS)
 
== HPI  ==
 
#'''True motor weakness (neuromuscular weakness)? Bilateral or unilateral (distribution of weakness)?'''
##Bilateral weakness:
###With symmetric ascending paralysis? GBS (MCC of symmetric paralysis).
###With motor weakness involving both CN and peripheral nerves? Inflammatory/Autoimmune (MS, transverse myelitis, MG), toxic/metabolic (botulism).
###With discrete sensory level and/or bladder dysfxn? Spinal cord lesion.
###With involvement of proximal > distal musculature? Myopathy (poly/dermatomyositis).
###Unilateral: Hemiparesis (unilateral weakness), hemiplegia (unilateral paralysis) is more likely in 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).
##In adults >50, especially women, generalized weakness complaint should prompt consideration for cardiac ischemia.
##In adults >65 weakness may be only Sx of serious infection, electrolyte disturbance, or CV compromise.
#'''Onset of weakness sudden or gradual?'''
##Sudden onset suggests vaso-occlusive etiology (CVA, TIA). Difficult to assess time of onset given pt may be unaware (sleeping).
##Gradual onset likely non-vascular. Think inflammatory CNS (MS, transverse myelitis), inflammatory MSK (myositis), compression neuropathy (CTS), autoimmune (MG, GBS), or toxins/metabolic process.
#'''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 with repetitive motions? NMJ pathology like MG (difficulty chewing, typing, eyelid droop, diplopia, etc).
#'''Associated Sx?'''
##HA: think SAH, epidural/SDH, complicated migraines (young females), not usually associated with stroke/TIA unless having ↑ICP.
##Vision changes: diplopia think posterior circulation stroke (CN III problem), visual field loss, MG.
##SOB: think CV etiology.
##CP or neck pain: think acute arterial dissection (thoracic aorta vs carotid/vert arteries), AMI.
##Abdominal or back pain:
###Abd pain with alteration of bowel habits, melena/hematochezia? Botulism, organophosphate poisoning, toxins, GBS, electrolyte imbalance.
###with LE weakness? could be AAA with spinal cord infarction.
###Back pain with unilateral weakness? Herniated disk with nerve impingement.
###BLE weakness with sensory level, priapism, in setting of trauma? think SCI, cauda equina syndrome, primary spinal cord lesion, compressive spinal cord lesions (epidural abscess/hematoma).
##N/V: sign of ↑ ICP, can lead to electrolyte imbalances.
##Rash: dermatomyositis.
#Ask about recent infectious illness, trauma, toxin exposure, alcohol, drug use (cocaine leading to TIA, SAH, stroke). Review meds for bblocker, diuretics, psychotropic meds that may alter electrolytes or cause side effects.
 
== Physical Exam  ==
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.
 
=== Neuro Exam Findings ===
 
==== Upper Motor Neuron  ====
 
*BRAIN
**Weakness - variable
**Bowel/Bladder - 
**Reflexes - increased
**Sens - diminished
**Pain - no
**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 - +/-
 
=== Intubation Indications  ===
 
#Severe fatigue
#Inability protect airway
#Rapidly increasing PaCO2
#Hypoxemia despite O2
#FVC &lt;12 mL/kg
#Neg Insp Force &lt;20 cm H2O


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


8/15/13 CELEDON (adapted from Rosen, Tintinalli, Intro to Clincal EM, Lampe, Birnbaumer, Donaldson)
==Disposition==
*Depends on process
**If normal initial workup, make sure has no respiratory compromise


==See Also==


==External Links==


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

Revision as of 16:08, 4 March 2020

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 (mypoathies)
  • 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)
  • LP (CNS infection, GBS)

Management

Intubation Indications

  • Severe fatigue
  • Inability 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