What conditions mimic elevated Intracranial Pressure (ICP) symptoms?

Conditions That Mimic Elevated Intracranial Pressure

Primary headache disorders, particularly migraine and new daily persistent headache, are the most common mimics of elevated ICP symptoms, as they can present with severe headache, nausea, vomiting, and visual disturbances without actual intracranial hypertension. 1

Primary Headache Disorders

• Migraine can closely mimic elevated ICP with severe headache, nausea, vomiting, photophobia, and visual disturbances, but without papilledema or elevated opening pressure on lumbar puncture 1
• New daily persistent headache syndromes should be considered when symptoms persist after a negative full imaging workup for spontaneous intracranial hypotension, which itself can mimic ICP symptoms 1
• The headache phenotype in idiopathic intracranial hypertension is highly variable and may mimic other primary headache disorders, making differentiation challenging 1

Intracranial Hypotension (Spontaneous or Post-Dural Puncture)

• Spontaneous intracranial hypotension (SIH) presents with orthostatic headache that can be confused with elevated ICP, though the postural component is key to differentiation 1
• Symptoms include headache, nausea, vomiting, photophobia, and rarely decreased consciousness—overlapping significantly with elevated ICP presentation 2
• Imaging findings in SIH (pachymeningeal enhancement, subdural collections, venous sinus engorgement) can paradoxically suggest elevated pressure 1
• Post-dural puncture headaches following spinal procedures are self-limiting and typically do not require imaging workup unless atypical features are present 1

Cervicogenic Headaches

• Cervicogenic headaches originating from neck pathology can present with severe headache, neck pain, and dizziness that overlap with ICP symptoms 1
• These should be considered in the differential when full imaging workup for intracranial hypotension is negative 1

Positional Orthostatic Tachycardia Syndrome (POTS)

• POTS can mimic elevated ICP with dizziness, headache, and cognitive disturbances, particularly when symptoms persist after negative imaging 1
• This autonomic disorder should be considered when postural symptoms are prominent but imaging and CSF studies are normal 1

Secondary Causes of Pseudotumor Cerebri Syndrome

• Cerebral venous sinus thrombosis can present identically to idiopathic intracranial hypertension with headache, papilledema, and visual symptoms 1
• Medications including tetracyclines, vitamin A, retinoids, steroids, growth hormone, thyroxine, and lithium can cause secondary intracranial hypertension 1
• Endocrine disorders such as Addison disease and hypoparathyroidism may present with symptoms mimicking elevated ICP 1
• Intracranial arteriovenous fistulas can cause venous hypertension with symptoms identical to elevated ICP 1

Key Distinguishing Features

Clinical Assessment

• Papilledema on fundoscopic examination is the most reliable clinical sign of true elevated ICP, though it may be absent in acute onset 3
• Sixth nerve palsy causing horizontal diplopia is more specific for elevated ICP than other cranial nerve findings 1, 3
• Transient visual obscurations (brief bilateral darkening of vision lasting seconds) are characteristic of elevated ICP but not pathognomonic 1

Diagnostic Confirmation

• Lumbar puncture with opening pressure >200 mm H₂O (or >250-280 mm CSF in children) definitively confirms elevated ICP 1, 3
• Normal CSF composition is required for idiopathic intracranial hypertension diagnosis; abnormal CSF suggests alternative diagnoses 1
• Neuroimaging findings including compressed basal cisterns, midline shift >5 mm, and disappearance of cerebral ventricles confirm true elevated ICP 1, 3

Common Pitfalls to Avoid

• Do not assume papilledema is always present—it may be absent despite significantly elevated ICP, especially in acute presentations 3
• Do not rely solely on symptoms—headache, nausea, vomiting, and visual disturbances are non-specific and occur in many conditions 1, 3
• Do not overlook medication history—many commonly prescribed drugs can cause secondary intracranial hypertension 1
• Do not dismiss normal initial imaging—some conditions like early idiopathic intracranial hypertension may have subtle or absent imaging findings initially 1