Idiopathic CSF dynamic disturbances causing headache: a narrative review

Area of Science:

• Neurology
• Neurosurgery
• Headache Medicine

Background:

• Idiopathic alterations in cerebrospinal fluid (CSF) dynamics frequently cause secondary headache disorders.
• Idiopathic Intracranial Hypertension (IIH), Spontaneous Intracranial Hypotension (SIH), and Idiopathic Normal Pressure Hydrocephalus (iNPH) are common, but their headache presentations are not fully understood.
• Headache in iNPH is often overlooked despite real-world evidence suggesting its frequency.

Purpose of the Study:

• To review the clinical characteristics and pathophysiology of headache in IIH, SIH, and iNPH.
• To synthesize evidence on the management and outcomes of headache in these CSF dynamic disorders.
• To highlight atypical and overlapping headache presentations.

Main Methods:

• Comprehensive literature search across multiple databases.
• Review of representative clinical cases to illustrate imaging and headache features.
• Synthesis of existing evidence on management and outcomes.

Main Results:

• IIH headaches are typically bilateral, pressing/pulsatile (migraine-like/tension-type).
• SIH classically presents with orthostatic headache, but atypical forms (non-orthostatic, thunderclap, chronic daily) exist.
• Headache in iNPH (dull, holocranic) is reported in ~30% of patients; overlapping phenotypes and medication-overuse headache are common.

Conclusions:

• Headache in idiopathic CSF dynamic disorders is diverse and often underrecognized, particularly atypical or overlapping cases.
• Increased awareness of atypical headache features and the presence of headache in iNPH is essential for accurate diagnosis.
• Further research into the pathophysiology and management of headache in these conditions is warranted.