Neuroradiology of idopathic Intracranial Hypertension

1. Dr.Roopchand.PS
Senior Resident Academic
Department of Neurology
TDMC, Alappuzha
NEURORADIOLOGY - IIH

2. INTRODUCTION:
 A disorder of unknown etiology.
 Affects young obese females
 Presents with features of raised ICT and
papilledema.
 Otitic hydrocephalus – pre imaging era
 Pseudotumor ceribri –
pneumatoencephalogram era
 Benign intracranial hypertension ? Vision
 Idiopathic intracranial hypertension.

3. DIAGNOSTIC CRITERIA:
 Modified Dandy criteria
 Signs and symptoms of raised ICT
 No localizing neurologic signs (exception of a
unilateral or bilateral sixth nerve paresis)
 CSF may show increased pressure, but no cytologic
or chemical abnormalities.
 Normal to small symmetric ventricles
 Diagnostic lumbar puncture done with the patient in
the lateral decubitus position.
 MRI or MRV should be included to rule out
intracranial venous sinus thrombosis.
 Other causes of intracranial hypertension should be
ruled out

4. PATHOPHYSIOLOGY:
 Collapsible Dural venous sinuses
 Increased arterial blood flow.
 Obesity: increased intra abdominal pressure.

5. ETIOLOGY:
 Exposure to or withdrawal of drugs.
 Systemic diseases
 Disruption of cerebral venous flow
 Certain endocrine or metabolic disorders

6. CRITERIA FOR INCLUDING A DRUG OR A
DISEASE AS A CAUSE OF IIH:
 Radhakrishnan et al..
 At least 2 cases should have been described
 The reported cases should have met all the
criteria for the diagnosis of IIH.
 Intracranial dural sinus thrombosis should have
been ruled out with reasonable certainty
Radhakrishnan K, Ahlskog JE, Garrity JA, Kurland LT. Idiopathic intracranial
hypertension. Mayo Clin Proc. Feb 1994;69(2):169-80

7. PNEUMOENCEPHALOGRAM:

8. CT FINDINGS:
Optic nerve edema due to iih
Slit like ventricles

9. MRI:

10. pappilloedema, enlarged perioptic csf spaces with mild tortuosity of optic nerves,
empty sella , prominent suprasellar cistern

11. Posterior scleral flattening

12. Empty sella in IIH

13. Brain MRI (1.5
Tesla). (a)
Sagittal T2-
weighted
image
showing
empty sella
(white arrow);
(b) axial T2-
weighted
image
showing
buckling of
optic nerves
with normal
retro-orbital
structures; (c)
coronal T2-fat
saturated
image
showing
increased CSF
spaces
around
bilateral optic
nerves; (d) T1
post-contrast
coronal image