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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  ==


#Neuromuscular weakness involves derangement of CNS (UMN), PNS (LMN), the motor endplate, or the muscle:
==Clinical Features==
##Can't miss dx:
===History===
###UMN: Strokes, ICH, MS
*'''True motor weakness (neuromuscular weakness)? Bilateral or unilateral (distribution of weakness)?'''
###Spinal cord disease: Infection (epidural abscess), ischemia, trauma (transection or impingement/compression syndromes), inflammation (transverse myelitis), tumor.
**Bilateral weakness:
###Peripheral nerve disease: GBS, toxins (ciguatera), tick paralysis, DM neuropathy.
***Symmetric ascending paralysis? [[Guillain-Barre Syndrome]]
###NMJ disease: MG crisis, botulism, organophosphate poisoning, Lambert-Eaton.
***Weakness involving both central and peripheral nervous system? Inflammatory/Autoimmune or toxic/metabolic
###Muscle disease: dermatomyositis, polymyositis, alcoholic myopathy, rhabdo.
***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]]


===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.


#UPPER
{| class="wikitable"
##[[Multiple Sclerosis]]
| align="center" style="background:#f0f0f0;"|'''Location'''
##Poliomyelitis
| align="center" style="background:#f0f0f0;"|'''Weakness'''
##[[ALS]] (upper & lower motor)
| align="center" style="background:#f0f0f0;"|'''Bowel/Bladder'''
#CORD
| align="center" style="background:#f0f0f0;"|'''Reflexes'''
##Painful
| align="center" style="background:#f0f0f0;"|'''Sensory'''
###Cord compression
| align="center" style="background:#f0f0f0;"|'''Pain'''
##Painless
|-
###Transverse Myelitis
| '''Upper motor neuron'''||||||||||
###Spinal cord infarct
|-
###Intramedullary tumor
| Brain||Variable||||Increased ||Diminished||No
#NERVE
|-
##Guillian-Barre
| Brainstem|| "crossed" findings - ipsilateral cranial nerve weakness and contralateral hemiparesis||||||||
##Toxic neuropthy ([[Ciguatera]])
|-
##Tick paralysis
| Cord||Fixed level ||Yes ||Increased ||Diminished||+/-
##Diabetic neuropathy
|-
##Porphyria
| '''Lower motor neuron'''||||||||||
#MOTOR END PLATE
|-
##[[Myasthenia Gravis]]
| Nerve||Distal > proximal and ascends ||No||Diminished||Nl/parethesias||No
##[[Botulism]] (descending)
|-
##Organophosphate Poisoning
| '''End-plate/muscle'''||||||||||
##[[Lambert-Eaton]]
|-
#MUSCLE
| Motor end plate||Ocular, bulbar and descends, fatigable ||No||Nl/diminished||Nl/parethesias||No
##Painful
|-
###[[Rhabdo]]
| Muscle||Proximal > distal ||No||Nl/diminished||Normal||+/-
###Alcoholic
|}
###Myopathy
###Polymyositis
###Dermatomyositis
###Toxins
###Hypophos
###[[Hypokalemia]] - post prandial/ family hx/ thyroid
###Polymyalgia rheum
##Painless
###Familial periodic paralysis
###Endocrine
#MIXED
##Upper & Lower Motor Neuron
###[[ALS]]
##Sensory & Motor  
###Peripheral neuropathy
#NON-NEUROMUSCULAR
##[[MI]]
##Resp failure
##[[Sepsis]]
##Dehydration
##Anxiety
##Fibromyalgia/chronic fatigue
##Malignancy


== Workup  ==
==Differential Diagnosis==
On all pts:
{{Weakness DDX}}
#CBC (anemia)
#Chem 10 (electrolyte disturbance,hypoglycemia, uremia)
#ECG (Ischemia,hypo/hyperkalemia)


Consider:
==Evaluation==
#CK (mypoathies)
===Workup===
#ESR
'''On all patients:'''
#CXR and UA (pt w/infectious sx and elderly)
*CBC (anemia)
#FVC (if e/o resp compromise, i.e. Myasthenia, GBS)  
*Chem 10 ([[electrolyte disturbance]], [[hypoglycemia]], uremia)  
#CT head (if focal findings, AMS, h/o cancer, h/o any trauma in pt on anticoagulation)
*[[ECG]] ([[myocardial ischemia|Ischemia]], [[hypokalemia|hypo]]/[[hyperkalemia]])  
#LP (CNS infection, GBS)


== Diagnosis  ==
'''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)


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


*BRAIN
==Disposition==
**Weakness - variable
*Depends on process
**Bowel/Bladder -&nbsp;
**If normal initial workup, make sure has no respiratory compromise
**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  ===
==See Also==


*NERVE
==External Links==
**Weakness - distal &gt; proximal and ascends
**Bowel/Bladder - NO
**Reflexes - diminished
**Sens - nl/paresthesias
**Pain - no


=== End-Plate/Muscle  ===
==References==
 
<references/>
*MOTOR END PLATE
[[Category:Neurology]]
**Weakness - occular,bulbar and descends, fatigable
[[Category:Symptoms]]
**Bowel/Bladder - NO
**Reflexes - nl/diminished
**Sens - nl
**Pain - no
*MUSCLE
**Weakness - proximal &gt; distal
**Bowel/Bladder - NO
**Reflexes - nl/diminished
**Sens - nl
**Pain - +/-
 
 
 
== Emergent Threat/ED Workup  ==
 
#CORD
##paralysis
##MRI, neurologist
##consdier steroids in high suspicion
#NERVE
##resp failure
##FEV1, airway mgt, ticks?, neurologist
#MOTOR END PLATE
##resp failure
##FEV1, airway mgt, Tensilon Test?
#MUSCLE
##Rhabdo
##urine myoglobin, serum CK, BUN/Cr
##serum K+
 
=== 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  ==
 
2/26/06 DONALDSON (adapted from Rosen, Lampe, Birnbaumer)
 
adapted from Hockberger
 
[[Category:Neuro]]

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