PNNI.ORG Website

Pseudotumor Cerebrii

David Black PA-C

I. Epidemiology

A. Incidence

1. General Population: 0.9 per 100,000

2. Women aged 15-44 years: 3.5 per 100,000

3. Obese women aged 20-44 years: 19.3 per 100,000

B. Rare: similar Incidence as

1. Amyotrophic Lateral Sclerosis

2. Guillain Barre Syndrome

3. Muscular Dystrophy

II. Pathophysiology

A. Intracranial Hypertension

B. Optic disc edema

C. Causes transient Optic Nerve ischemia

III. Causes

A. See Increased Intracranial Pressure Causes

IV. Symptoms

A. Headache

1. Location: retro-orbital Headache

2. Provocative: eye movement worsens Headache

3. Timing: Chronic Daily Headache, worse on awakening

4. Characteristics: Throbbing Headache

5. Associated Symptoms: Nausea and Vomiting

B. Transient decreased visual acquity (75%)

1. Monocular or Binocular vision loss

2. Lasts for only a few seconds

3. Permanent visual changes occur in a few patients

a) Increased blind spot

b) Blurred Vision or Tunnel Vision

(1) Dark spot in temporal visual field

c) Profound Vision loss or blindness (severe cases)

4. Other visual changes

a) Photophobia

b) Diplopia

C. Pulsatile Tinnitus (60%)

1. Unilateral or bilateral "whooshing" sound

2. Palliative:

a) Lumbar Puncture

b) Jugular venous compression

D. Musculoskelatal symptoms

1. Neck pain or neck stiffness

2. Back pain

3. Arthralgias (shoulder, wrist, knee)

E. Neurologic Symptoms and Psychiatric Symptoms

1. Paresthesias

2. Radicular pain

3. Facial palsy

4. Impaired concentration or memory

5. Major Depression

V. Signs

A. Papilledema

1. Best observed by stereoscopic indirect Ophthalmoscopy

2. Not predictive of visual outcome

B. Visual field defects

1. Best detected by perimetry (visual field testing)

2. Blind spot enlargement

3. Inferonasal visual loss

4. Visual field constriction (tunnel vision)

C. Decreased Ocular motility

VI. Diagnostics

A. Lumbar Puncture

1. Opening Pressure consistent with Pseudotumor Cerebri

a) Obese Patient > 250 mm of water

b) Nonobese Patient > 200 mm of water

2. Opening Pressure falsely elevated by

a) Sitting position

b) Prone position (fluoroscopy)

c) Painful tap

d) Anxiety

(1) Consider pretreating LP with Valium dose

3. Send CSF for spinal fluid analysis

a) CSF Glucose

b) CSF Protein

c) CSF Cell Count

d) CSF cultures (bacteria, fungi, Tuberculosis)

e) CSF Cytology

VII. Radiology

A. Head MRI

VIII. Differential Diagnosis

  A. Migraine Headache

  B. Chronic Daily Headache

  C. Rebound Headache (Analgesic overuse)

IX. Management: Medical

A. Weight loss

B. Dietary changes

1. Low salt diet

2. Low tyramine diet

C. Avoid sulfa conjugated medications

D. Diuretic

1. Acetazolamide (Diamox)

a) Dose: 1 to 4 grams daily divided bid-tid

2. Furosemide (Lasix)

E. Systemic Corticosteroids

1. Reserved for urgent management of vision loss

F. Headache Management

1. Acute Treatment: NSAIDs

2. Prophylaxis: Tricyclic Antidepressants

G. Therepeutic large volume Lumbar Puncture

1. Removal of 20 ml of spinal fluid

X. Management: Surgical

A. Optic Nerve Sheath Decompression

1. Indicated for associated decreased visual acquity

2. Window or fenestration cut in Optic Nerve sheath

B) Results in increased blood flow to the Optic Nerve

C) Cerebrospinal Fluid Shunt

  (1) Lumboperitoneal shunt (preferred over ventricular)

  (2) Short term: Very effective

  (3) Long term: Multiple revisions often required

XI. Management: Pregnancy

A. Careful follow-up

1. Frequent Neurology evaluation

2. Frequent Ophthalmology evaluation

3. Repeated Lumbar Puncture monitoring

B. Intervention

1. Acetazolamide (Diamox) after 20 weeks gestation

2. Systemic Corticosteroids for vision deterioration

3. Optic Nerve Sheath Decompression

4. Ventriculoperitoneal Shunt

C. Contraindicated Agents

1. Avoid Tricyclic Antidepressants

2. Avoid Thiazide Diuretics

XII. References

A. Friedman (1999) Neurosurg Clin North Am 10(4):609-21/

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