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10 marksDrNB 2025NeurologyCSF Disorders
Discuss the various presentations, diagnosis and management of spontaneous intracranial hypotension. [3+3+4]
Spontaneous intracranial hypotension (SIH) is a syndrome caused by cerebrospinal fluid (CSF) volume depletion due to spontaneous CSF leak, leading to low CSF pressure and orthostatic headache (Harrison's 21e, Ch. 265).
SIH results from spontaneous dural tears or CSF leaks along the spinal axis, often at the cervicothoracic junction. Loss of CSF volume decreases buoyancy and causes brain sagging, leading to characteristic symptoms.
| Mechanism | Description |
|---|---|
| CSF Leak | Spontaneous dural tear or meningeal diverticula rupture |
| Typical Sites | Cervicothoracic spine, thoracic spine |
| Risk Factors | Connective tissue disorders (e.g., Marfan, Ehlers-Danlos), trivial trauma, spinal degenerative changes |
| Pathophysiology | ↓CSF volume → ↓CSF pressure → compensatory venous dilation and brain sagging |
SIH classification by leak type:
| Type | Description |
|---|---|
| Type 1 | Ventral dural tear |
| Type 2 | Ruptured meningeal diverticula |
| Type 3 | CSF-venous fistula |
(Harrison's 21e, Ch. 265; Bradley's Neurology in Clinical Practice, 8e)
References
Harrison's 21e, Ch. 265Harrison's 21e, Ch. 265; Bradley's Neurology in Clinical PracticeHarrison's 21e, Ch. 265; Bradley's Neurology in Clinical Practice, 8e