Pseudotumor Cerebri




Abstract


Pseudotumor cerebri is a relatively common cause of headache. It has an incidence of 2.2 per 100,000 patients, approximately the same incidence as cluster headache. Also known as idiopathic intracranial hypertension, pseudotumor cerebri is seen most frequently in overweight women between the ages of 20 and 45 years. An increased incidence of pseudotumor cerebri is also associated with pregnancy. The exact cause of pseudotumor cerebri has not been elucidated, but the common denominator appears to be a defect in the absorption of cerebrospinal fluid (CSF). Predisposing factors include ingestion of various medications including tetracycline, vitamin A, corticosteroids, and nalidixic acid. Other implicating factors include blood dyscrasias, anemias, endocrinopathies, and chronic respiratory insufficiency. In many patients, however, the exact cause of pseudotumor cerebri remains unknown.




Keywords

pseudotumor cerebri, obesity, vitamin A, tetracycline, nalidixic acid, headache, Valsalva maneuver, papilledema, lumbar puncture

 


ICD-10 CODE G93.2




The Clinical Syndrome


An often missed diagnosis, pseudotumor cerebri is a relatively common cause of headache. It has an incidence of 2.2 per 100,000 patients, approximately the same incidence as cluster headache. Also known as idiopathic intracranial hypertension, pseudotumor cerebri is seen most frequently in overweight women between the ages of 20 and 45 years. If epidemiologic studies look only at obese women, the incidence increases to approximately 20 cases per 100,000 patients. An increased incidence of pseudotumor cerebri is also associated with pregnancy. The exact cause of pseudotumor cerebri has not been elucidated, but the common denominator appears to be a defect in the absorption of cerebrospinal fluid (CSF). Predisposing factors include ingestion of various medications including tetracycline, vitamin A, corticosteroids, and nalidixic acid ( Box 8.1 ). Other implicating factors include blood dyscrasias, anemias, endocrinopathies, and chronic respiratory insufficiency. In many patients, however, the exact cause of pseudotumor cerebri remains unknown.



Box 8.1

Medications Reportedly Associated With Intracranial Hypertension


Vitamins





  • Vitamin A



  • Retinol



  • Retinoids



Antibiotics





  • Tetracycline and derivatives



  • Nalidixic acid



  • Nitrofurantoin



  • Penicillin



Protein Kinase C Inhibitors





  • Lithium carbonate



Histamine (H 2 )-Receptor Antagonists





  • Cimetidine



Steroids





  • Corticosteroid withdrawal



  • Levonorgestrel



  • Danazol



  • Leuprolide acetate



  • Tamoxifen



  • Growth hormone



  • Oxytocin



  • Anabolic steroids



Nonsteroidal Antiinflammatory Drugs





  • Ketoprofen



  • Indomethacin



  • Rofecoxib



Antiarrhythmics





  • Amiodarone



Anticonvulsants





  • Phenytoin



Dopamine Precursors





  • Levodopa



  • Carbidopa






Signs and Symptoms


More than 90% of patients suffering from pseudotumor cerebri present with the complaint of headache, are female, and have headaches that increase with the Valsalva maneuver. Associated nonspecific central nervous system signs and symptoms, such as dizziness, visual disturbance including diplopia, tinnitus, photophobia, nausea and vomiting, and ocular pain can often obfuscate what should otherwise be a reasonably straightforward diagnosis, given that basically all patients suffering from pseudotumor cerebri (1) have papilledema on fundoscopic examination ( Fig. 8.1 ), (2) are female, and (3) are obese. The extent of papilledema varies from patient to patient and may be associated with subtle visual field defects including an enlarged blind spot and inferior nasal visual field defects ( Fig. 8.2 ). If the condition is untreated, blindness may result ( Fig. 8.3 ).


Sep 9, 2019 | Posted by in PAIN MEDICINE | Comments Off on Pseudotumor Cerebri

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