View source for Weakness

==Background==

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

==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]]

===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. 

{| 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||+/-
|}

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

==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)

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