Weakness: Difference between revisions

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== Background ==
==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.


==Clincial Features==
==Clinical Features==
=== History ===
===History===
*'''True motor weakness (neuromuscular weakness)? Bilateral or unilateral (distribution of weakness)?'''  
*'''True motor weakness (neuromuscular weakness)? Bilateral or unilateral (distribution of weakness)?'''  
**Bilateral weakness:  
**Bilateral weakness:  
***W/symmetric ascending paralysis? [[Guillain-Barre Syndrome]]
***Symmetric ascending paralysis? [[Guillain-Barre Syndrome]]
***W/weakness involving both CN + PNS? Inflammatory/Autoimmune or toxic/metabolic  
***Weakness involving both central and peripheral nervous system? Inflammatory/Autoimmune or toxic/metabolic  
***W/discrete sensory level and/or bladder dysfxn? [[Spinal Cord Lesion]]  
***Discrete sensory level and/or bladder dysfunction? [[Spinal Cord Lesion]]  
***W/involvement of proximal > distal musculature? Myopathy  
***Involvement of proximal > distal musculature? Myopathy  
**Unilateral weakness: [[CVA]], [[TIA]]  
**Unilateral weakness: [[CVA]], [[TIA]]  
*'''If non-neuromuscular weakness''' then BROAD Ddx obtain:  
*'''If non-neuromuscular weakness''' then BROAD differential, 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)
**[[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?'''  
*'''Onset of weakness sudden or gradual?'''  
**Sudden suggests vaso-occlusive etiology [[CVA]]/[[TIA]]  
**Sudden suggests vaso-occlusive etiology [[CVA]]/[[TIA]]  
**Gradual onset likely non-vascular  
**Gradual onset likely non-vascular  
*'''Significant event surrounding onset of weakness?'''  
*'''Significant event surrounding onset of weakness?'''  
**SZ prior to weakness? Todd’s paralysis
**[[Seizure]] prior to weakness? Todd’s paralysis
**Migraine HA? Complicated migraine
**Migraine headache? Complicated [[migraine]]
**Sudden onset of severe HA? [[SAH]]
**Sudden onset of severe headache? [[SAH]]
**Trauma? Epidural or [[Subdural Hematoma]]
**Trauma? Epidural or [[Subdural Hematoma]]
**Severe migratory neck or chest pain? Arterial dissection syndromes  
**Severe migratory neck or chest pain? [[vertebral and carotid artery dissection|Arterial dissection syndromes]]
*'''Temporal pattern to weakness? Fluctuating or fixed weakness?'''  
*'''Temporal pattern to weakness? Fluctuating or fixed weakness?'''  
**Weakness w/repetitive motions? NMJ pathology like [[Myasthenia Gravis]]
**Weakness with repetitive motions? Neuromuscular junction pathology like [[Myasthenia Gravis]]
*'''Associated Sx?'''  
*'''Associated symptoms?'''  
**HA:''' SAH, epidural/SDH, complicated migraines (young females), not usually stroke/TIA (unless high ICP)
**[[Headache]]: [[SAH]], epidural/[[SDH]], complicated migraines (young females), not usually stroke/TIA (unless high intracranial pressure)
**Vision changes: Posterior circulation stroke, [[Myasthenia Gravis]]
**[[visual disturbances|Vision changes]]: Posterior circulation [[stroke]], [[Myasthenia Gravis]]
**SOB: CV etiology
**[[Shortness of breath]]: cardiovascular etiology
**CP or neck pain: Acute arterial dissection, [[AMI]]
**[[Chest pain]] or [[neck pain]]: Acute [[vertebral and carotid artery dissection|carotid/vertebral]]/[[aortic dissection]], [[AMI]]
**Abdominal or back pain:
**[[abdominal pain|Abdominal]] or [[back pain]]:
***w/alteration of bowel habits? [[Botulism]], organophosphate poisoning, toxins, [[Guillain-Barre Syndrome]], [[Electrolyte Imbalance]].  
***with alteration of bowel habits? [[Botulism]], organophosphate poisoning, toxins, [[Guillain-Barre Syndrome]], [[Electrolyte Imbalance]].  
***w/LE weakness? [[AAA]] with spinal cord infarction
***with lower extremity weakness? [[AAA]] with spinal cord infarction
***Back pain with unilateral weakness? Herniated disk w/nerve impingement
***[[Back pain]] with unilateral weakness? Herniated disk with nerve impingement
***BLE weakness w/sensory level s/p trauma? SCI, [[Cauda Equina Syndrome]]  
***Bilateral weakness with sensory level s/p trauma? [[spinal cord injury|SCI]], [[Cauda Equina Syndrome]]  
**N/V: sign of ↑ ICP, can lead to electrolyte imbalances
**[[Nausea/vomiting]]: sign of [[elevated ICP|↑ ICP]], can lead to [[electrolyte imbalances]]
**Rash: Dermatomyositis
**Rash: [[Dermatomyositis]]


=== Physical Exam ===
===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.  
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.  


==== Upper Motor Neuron  ====
{| class="wikitable"
*BRAIN
| align="center" style="background:#f0f0f0;"|'''Location'''
**Weakness - variable
| align="center" style="background:#f0f0f0;"|'''Weakness'''
**Bowel/Bladder -
| align="center" style="background:#f0f0f0;"|'''Bowel/Bladder'''
**Reflexes - increased
| align="center" style="background:#f0f0f0;"|'''Reflexes'''
**Sens - diminished
| align="center" style="background:#f0f0f0;"|'''Sensory'''
**Pain - no
| align="center" style="background:#f0f0f0;"|'''Pain'''
**Asymmetric/unilateral
|-
*BRAINSTEM
| '''Upper motor neuron'''||||||||||
**"crossed" findings - ipsilateral cranial nerve weakness and contralateral hemiparesis
|-
*CORD
| Brain||Variable||||Increased ||Diminished||No
**Weakness - fixed level  
|-
**Bowel/Bladder - YES
| Brainstem|| "crossed" findings - ipsilateral cranial nerve weakness and contralateral hemiparesis||||||||
**Reflexes - increased
|-
**Sens - diminished
| Cord||Fixed level ||Yes ||Increased ||Diminished||+/-
**Pain - +/-
|-
 
| '''Lower motor neuron'''||||||||||
==== Lower Motor Neuron  ====
|-
*NERVE
| Nerve||Distal > proximal and ascends ||No||Diminished||Nl/parethesias||No
**Weakness - distal > proximal and ascends  
|-
**Bowel/Bladder - NO
| '''End-plate/muscle'''||||||||||
**Reflexes - diminished
|-
**Sens - nl/paresthesias
| Motor end plate||Ocular, bulbar and descends, fatigable ||No||Nl/diminished||Nl/parethesias||No
**Pain - no
|-
 
| Muscle||Proximal > distal ||No||Nl/diminished||Normal||+/-
==== 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 > distal  
**Bowel/Bladder - NO
**Reflexes - nl/diminished  
**Sens - nl
**Pain - +/-


==Differential Diagnosis==
==Differential Diagnosis==
{{Weakness DDX}}
{{Weakness DDX}}


==Diagnosis==
==Evaluation==
=== Workup ===
===Workup===
'''On all pts:'''
'''On all patients:'''
*CBC (anemia)
*CBC (anemia)
*Chem 10 (electrolyte disturbance,hypoglycemia, uremia)  
*Chem 10 ([[electrolyte disturbance]], [[hypoglycemia]], uremia)  
*ECG (Ischemia,hypo/hyperkalemia)  
*[[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)
 


==Treatment==
==Management==
=== Intubation Indications ===
===[[Intubation]] Indications===
*Severe fatigue  
*Severe fatigue  
*Inability protect airway  
*Inability protect airway  
*Rapidly increasing PaCO2  
*Rapidly increasing PaCO2  
*Hypoxemia despite O2  
*[[Hypoxemia]] despite O2  
*FVC <12 mL/kg  
*FVC <12 mL/kg  
*Neg Insp Force <20 cm H2O
*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==
==References==
 
<references/>
[[Category:Neuro]]
[[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