Causes of acute muscle weakness in children

Anatomic region	Condition
Cerebral cortex	Intracranial hemorrhage (SAH)^* Head trauma (EDH, SDH)^* Stroke (thrombotic or embolic)^* Brain tumor^* Postictal Todd paralysis Hemisyndrome migraine Alternating hemiplegia of childhood
Spinal cord	Spinal cord trauma (eg, EDH)^* Spinal cord tumor^* Discitis (vertebral osteomyelitis) Epidural abscess^* Transverse myelitis Vascular abnormality (ie, stroke)
Anterior horn cell	Poliomyelitis, other enteroviruses, acute flaccid myelitis^*
Peripheral nerve	Guillain-Barré syndrome^* Ciguatera poisoning^* Heavy metal poisoning (eg, arsenic, mercury)^* Paralytic shellfish poisoning^* Acute intermittent porphyria^* Other acquired peripheral neuropathy^¶
Neuromuscular junction	Botulism^* Myasthenia gravis^* Organophosphate poisoning^* Neurotoxic snake envenomation^* Tick paralysis^*
Muscle	Rhabdomyolysis^* Viral myositis Pyomyositis Periodic paralysis (may be associated with high, low, or normal potassium) Trichinellosis
Other	Electrolyte disturbance (eg, hypokalemia, hypophosphatemia, hypocalcemia, hyponatremia)^* Drug-related^Δ Functional neurologic disorder (conversion disorder)

EDH: epidural hematoma; SAH: subarachnoid hemorrhage; SDH: subdural hematoma.

* Life-threatening condition.

¶ Refer to UpToDate review on overview of acquired peripheral neuropathies in children.

Δ Refer to UpToDate content on drugs and toxins that can cause polyneuropathy.

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