Difference between revisions of "Weakness"

(Text replacement - "e/o" to "evidence of")
(History)
Line 8: Line 8:
 
**Bilateral weakness:  
 
**Bilateral weakness:  
 
***Symmetric ascending paralysis? [[Guillain-Barre Syndrome]]
 
***Symmetric ascending paralysis? [[Guillain-Barre Syndrome]]
***Weakness involving both CN + PNS? Inflammatory/Autoimmune or toxic/metabolic  
+
***Weakness involving both central and peripheral nervous system? Inflammatory/Autoimmune or toxic/metabolic  
***Discrete sensory level and/or bladder dysfxn? [[Spinal Cord Lesion]]  
+
***Discrete sensory level and/or bladder dysfunction? [[Spinal Cord Lesion]]  
 
***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 cx, UA/UCx, drug levels, CXR, Consider Head CT (focal deficit, 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? 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 w/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]]
 
**Vision changes: Posterior circulation stroke, [[Myasthenia Gravis]]
**SOB: CV etiology
+
**Shortness of breath: CV etiology
**CP or neck pain: Acute arterial dissection, [[AMI]]
+
**Chest pain or neck pain: Acute arterial dissection, [[AMI]]
 
**Abdominal or back 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
+
***w/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 w/nerve impingement
***BLE weakness w/sensory level s/p trauma? SCI, [[Cauda Equina Syndrome]]  
+
***Bilateral weakness with sensory level s/p trauma? SCI, [[Cauda Equina Syndrome]]  
**N/V: sign of ↑ ICP, can lead to electrolyte imbalances
+
**Nausea/vomiting: sign of ↑ ICP, can lead to electrolyte imbalances
 
**Rash: Dermatomyositis
 
**Rash: Dermatomyositis
  

Revision as of 22:28, 13 July 2016

Background

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

Clincial 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 cx, UA/UCx, drug levels, CXR, Consider Head CT (focal deficit, 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? Arterial dissection syndromes
  • Temporal pattern to weakness? Fluctuating or fixed weakness?
    • Weakness w/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)
    • Vision changes: Posterior circulation stroke, Myasthenia Gravis
    • Shortness of breath: CV etiology
    • Chest pain or neck pain: Acute arterial dissection, AMI
    • Abdominal or back pain:
    • Nausea/vomiting: sign of ↑ 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.

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 Ooccular,bulbar and descends, fatigable No Nl/diminished Nl/parethesias No
Muscle Proximal > distal No Nl/diminished Normal +/-

Differential Diagnosis

Weakness

Diagnosis

Workup

On all patients:

Consider:

  • CK (mypoathies)
  • ESR
  • CXR and UA (if infectious symptoms or elderly)
  • FVC (if evidence of resp compromise, i.e. Myasthenia, GBS)
  • CT head (if focal findings, AMS, h/o cancer, h/o 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

References