What are the common causes of jitteriness in neonates?

Common Causes of Neonatal Jitteriness

Neonatal jitteriness most commonly results from metabolic derangements (hypoglycemia, hypocalcemia, hypomagnesemia) and maternal substance exposure, with benign idiopathic jitteriness being a diagnosis of exclusion after these treatable causes are ruled out. 1

Metabolic Causes (Most Common and Treatable)

Hypoglycemia

• Serum glucose testing should be performed immediately as hypoglycemia is one of the most common provoked causes of jitteriness 1
• Requires prompt reversal to prevent neurologic sequelae 1

Hypocalcemia

• Check serum calcium and magnesium levels as hypocalcemia commonly causes both provoked seizures and jitteriness 1
• Can occur secondary to excessive maternal calcium ingestion (3-6 g daily), which leads to transient neonatal hypoparathyroidism 2
• Typically presents with jitteriness and may progress to seizures if untreated 2

Hypomagnesemia

• Should be evaluated alongside calcium as part of the metabolic workup 1
• Often coexists with hypocalcemia 1

Maternal Substance Exposure (Increasingly Common)

Drug Withdrawal Syndromes

A comprehensive maternal drug history is essential, as neonatal withdrawal has increased 10-fold in recent years 3

• Opioids: Cause withdrawal in 55-94% of exposed neonates, with jitteriness as a cardinal feature of neonatal abstinence syndrome 3
• SSRIs: Present with tremors, irritability, and jitteriness within hours to days, lasting 1-4 weeks 3
• Benzodiazepines (including clonazepam): Cause tremors and jitteriness with onset from hours to weeks, potentially lasting 1.5-9 months 3
• Barbiturates: Produce severe tremors with onset in first 24 hours or delayed up to 10-14 days 3
• Caffeine: Causes jitteriness at birth, lasting 1-7 days 3
• Cocaine/stimulants: Produce neurobehavioral abnormalities including tremors and hyperactivity, typically on postnatal days 2-3 3

Critical Pitfall

Always inquire about over-the-counter medications and supplements, as parents may not consider antacids or herbal preparations as "drugs" 2

Benign Idiopathic Jitteriness

Clinical Features

• Occurs in otherwise healthy term neonates with normal metabolic workup 4, 5
• Associated with elevated norepinephrine levels (1276 vs 914 pg/mL in controls), suggesting increased sympathetic activity 4
• May persist beyond the neonatal period, resolving at mean age of 7.2 ± 3.4 months 5

Prognosis

• Excellent prognosis with 92% having normal neurodevelopment at 3 years when metabolic causes are excluded 5
• Represents a benign maturational process of the central nervous system 5
• Parents should be reassured about the benign nature when provoked causes are ruled out 1

Distinguishing Features from Seizures

Jitteriness differs from seizures by the following characteristics 6:

• Stimulus-sensitive (exacerbated by handling)
• Ceases with passive flexion of affected limb
• No abnormal eye movements or autonomic changes
• Predominantly affects limbs rather than face

Evaluation Algorithm

1. Immediate metabolic workup: Glucose, calcium, magnesium 1
2. Maternal substance history: Prescription medications, over-the-counter agents, illicit drugs 1, 2
3. Physical examination: Look for focal neurologic findings, abnormal tone, or dysmorphic features 3
4. Reserve neuroimaging and EEG for cases with focal findings, seizure concern, or atypical features 1

Management Priorities

• Immediately reverse any identified metabolic derangements 1
• Manage neonatal drug withdrawal syndromes if maternal substance exposure is confirmed 1
• Provide parental reassurance when metabolic and drug-related causes are excluded, as benign jitteriness has excellent prognosis 1, 5