Weakness: Difference between revisions

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==Background==
==Background==
Acute/Generalized


==Workup==
Determine if patient has actual neuromuscular weakness (suggesting CNS dysfunction) or non-neuromuscular weakness.
#cbc
#chem 10  (esp. K, Mg, Ca, Phos)
#ecg
#+/- CK (r/o myopathy)
#+/- FVC (eval impending resp failure, i.e. Myasthenia)
#+/- ABG/CT/LP/TSH/UA (rhabdo)


==Diagnosis==
==Clinical Features==
===UPPER MOTOR NEURON===
===History===
# BRAIN
*'''True motor weakness (neuromuscular weakness)? Bilateral or unilateral (distribution of weakness)?'''
*Weakness - variable
**Bilateral weakness:
*Bowel/Bladder -
***Symmetric ascending paralysis? [[Guillain-Barre Syndrome]]
*Reflexes - increased
***Weakness involving both central and peripheral nervous system? Inflammatory/Autoimmune or toxic/metabolic
*Sens - diminished
***Discrete sensory level and/or bladder dysfunction? [[Spinal Cord Lesion]]
*Pain - no
***Involvement of proximal > distal musculature? Myopathy
*Asymmetric/unilateral
**Unilateral weakness: [[CVA]], [[TIA]]
# CORD
*'''If non-neuromuscular weakness''' then BROAD differential, obtain:
*Weakness - fixed level
**[[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]]


    Bowel/Bladder - YES
===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.


    Reflexes - increased
{| class="wikitable"
| 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||+/-
|}


    Sens - diminished
==Differential Diagnosis==
{{Weakness DDX}}


    Pain - +/-
==Evaluation==
===Workup===
'''On all patients:'''
*CBC (anemia)
*Chem 10 ([[electrolyte disturbance]], [[hypoglycemia]], uremia)
*[[ECG]] ([[myocardial ischemia|Ischemia]], [[hypokalemia|hypo]]/[[hyperkalemia]])


'''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)


LOWER 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


III. NERVE
==Disposition==
*Depends on process
**If normal initial workup, make sure has no respiratory compromise


    Weakness - distal and ascends
==See Also==


    Bowel/Bladder - NO
==External Links==


    Reflexes - diminished
==References==
 
<references/>
    Sens - nl/paresthesias
[[Category:Neurology]]
 
[[Category:Symptoms]]
    Pain - no
 
 
END-PLATE/MUSCLE
 
IV. MOTOR END PLATE
 
    Weakness - head and descends
 
    Bowel/Bladder - NO
 
    Reflexes - nl/diminished
 
    Sens - nl
 
    Pain - no
 
 
V. MUSCLE
 
    Weakness - proximal
 
    Bowel/Bladder - NO
 
    Reflexes - nl/diminished
 
    Sens - nl
 
    Pain - +/-
 
 
DIFFERENTIAL DIAGNOSIS
 
I. UPPER
 
    A) Multiple sclerosis
 
    B) Poliomyelitis
 
    C) ALS (upper & lower motor)
 
II. CORD
 
    A) Painful
 
          i) Cord compression
 
    B) Painless
 
          i) Transverse myelitis
 
          ii) Spinal cord infarct
 
          iii) Intramedullary tumor
 
III. NERVE
 
    A) Guillian-Barre
 
    B) Toxic neuropthy (Ciguatera)
 
    C) Tick paralysis
 
    D) Diabetic neuropathy
 
    E) Porphyria
 
IV. MOTOR END PLATE
 
    A) Myasthenia gravis
 
    B) Botulism (descending)
 
    C) Organophosphate poisoning
 
    D) Lambert-Eaton
 
V. MUSCLE
 
    A) Painful
 
          i) Rhabdo
 
          ii) Alcoholic
 
          iii) Myopathy
 
          iv) Polymyositis
 
          v) Dermatomyositis
 
          vi) Toxins
 
          vii) Hypophos
 
          viii) Hypo-kalemia
 
          ix) Polymyalgia rheum
 
    B) Painless
 
          i) Familial periodic paralysis
 
          ii) Endocrine
 
VI. MIXED
 
    A) Upper & Lower Motor Neuron
 
          i) ALS
 
    B) Sensory & Motor
 
          i)
 
VII. NON-NEUROMUSCULAR
 
    A) MI
 
    B) Resp failure
 
    C) Sepsis
 
    D) Dehydration
 
    E) Anxiety
 
    F) Fibromyalgia/chronic fatigue
 
    G) Malignancy
 
 
EMERGENT THREAT/ED WORKUP
 
I. CORD
 
    - paralysis
 
    - MRI, neurologist
 
2. NERVE
 
    - resp failure
 
    - FEV1, airway mgt, ticks?, neurologist
 
3. MOTOR END PLATE
 
    - resp failure
 
    - FEV1, airway mgt, Tensilon Test?
 
4. MUSCLE
 
    - Rhabdo
 
    - urine myoglobin, serum CK, BUN/Cr
 
    serum K+
 
 
INTUBATION INDICATIONS
 
1) Severe fatigue
 
2) Inability protect airway
 
3) Rapidly increasing PaCO2
 
4) Hypoxemia despite O2
 
5) FVC <12 mL/kg
 
6) Neg Insp Force <20 cm H2O
 
 
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