Pseudotumor cerebri with amiodarone

Neurological complications of cardiovascular drugs

Cardiovascular drugs are used to treat arterial hypertension, hyperlipidemia, arrhythmias, heart failure, and coronary artery disease. They also include antiplatelet and anticoagulant drugs that are essential for prevention of cardiogenic embolism. Most neurologic complications of the cardiovascular drugs are minor or transient and are far outweighed by the anticipated benefits of treatment. Other neurologic complications are more serious and require early recognition and management. Overtreatment of arterial hypertension may cause lightheadedness or fatigue but often responds readily to dose adjustment or an alternative drug. Other drug complications may be more troublesome as in myalgia associated with statins or headache associated with vasodilators. The recognized bleeding risk of the antithrombotics requires careful calculation of risk/benefit ratios for individual patients. Many neurologic complications of cardiovascular drugs are well documented in clinical trials with known frequency and severity, but others are rare and recognized only in isolated case reports or small case series. This chapter draws on both sources to report the adverse effects on muscle, nerve, and brain associated with commonly used cardiovascular drugs.

Amiodarone-associated optic neuropathy: a critical review

Although amiodarone is the most commonly prescribed anti-arrhythmic drug, its use is limited by serious toxicities, including optic neuropathy. Current reports of amiodarone-associated optic neuropathy identified from the Food and Drug Administration's Adverse Event Reporting System and published case reports were reviewed. A total of 296 reports were identified: 214 from the Adverse Event Reporting System, 59 from published case reports, and 23 from adverse events reports for patients enrolled in clinical trials. Mean duration of amiodarone therapy before vision loss was 9 months (range 1-84 months). Insidious onset of amiodarone-associated optic neuropathy (44%) was the most common presentation, and nearly one third were asymptomatic. Optic disk edema was present in 85% of cases. Following drug cessation, 58% had improved visual acuity, 21% were unchanged, and 21% had further decreased visual acuity. Legal blindness (<20/200) was noted in at least one eye in 20% of cases. Close ophthalmologic surveillance of patients during the tenure of amiodarone administration is warranted.

The clinical spectrum of amiodarone-associated optic neuropathy

PURPOSE

To describe the clinical spectrum of amiodarone-associated optic neuropathy.

METHODS

Observational cases series and review.

RESULTS

Of 55 cases, the median interval for onset of optic neuropathy was four months after initiating amiodarone; 88% occurred within 12 months. Seven (13%) patients were asymptomatic. Twenty-two (40%) patients presented with sudden visual loss, while 26 (47%) had insidious loss of vision. Visual acuity ranged from 20/15 to light perception; 10 (18%) patients had legal blindness with visual acuity of 20/200 or worse. Visual field loss was present in 91% of cases. Color vision loss was present in eight (40%) of 20 cases. Optic disc edema was present in 85% of cases, while eight (15%) patients had retrobulbar optic neuropathy, without evidence of disc edema. Optic disc edema resolved over a median time of three months. Five patients had raised intracranial pressure on lumbar puncture.

CONCLUSION

We were able to classify amiodarone-associated optic neuropathy into five clinical categories with respect to temporal characteristics and optic nerve appearance: insidious-onset (43%), acute-onset (28%), retrobulbar (13%), increased intracranial pressure (8%), and delayed-progressive onset (8%). Most cases of optic neuropathy commenced within 12 months of initiating amiodarone, with the median onset being four months. Over 10% of patients will have no visual symptoms at the onset. Ophthalmologic examinations within the first 12 months--and particularly within four months of initiating amiodarone--should improve early detection of amiodarone-associated optic neuropathy.

Medications and substances as a cause of headache: a systematic review of the literature

Medication- or substance-induced headache is probably an underrecognized entity with numerous etiologies, including prescribed medication, over-the-counter medication, illicit drugs, anesthetic agents, foods, food additives, beverages, vitamins, inhaled substances, and substances used in diagnostic procedures. The author performs a systemic review of the literature to provide an exhaustive description of the relationship between medications and substances and headaches of various types, along with pathophysiologic mechanisms whenever possible. Suggestions for improved identification of this phenomenon and its avoidance are provided. More scientific evaluation of substances and their possible association with headache is required with almost all substances indicated herein.

Disk edema subsequent to renal transplantation

A 12-year-old child was discovered (following successful renal transplantation) to have asymptomatic bilateral disk edema with preservation of optic nerve function. He had been maintained on cyclosporine, imuran and prednisone. Evaluation revealed normal intracranial imaging and normal CSF though under elevated intracranial pressure. The contributing possibilities to this papilledema are considered, and include a secondary pseudotumor cerebri syndrome of childhood and toxic effects of cyclosporine. The indications for treatment for pseudotumor cerebri are discussed, and clinicians are reminded to separate what we think about a case from how we behave in taking care of the patient.

Getting to the heart of visual loss: when cardiac medication may be dangerous to the optic nerves

A 62-year-old lady with hypertension and diabetes developed bilateral, sequential ischemic optic neuropathy, progressive in the right eye. Because of a reported association between amiodarone and optic neuropathy with disc edema, the patient discontinued taking this medication; however, her visual loss continued. The differential diagnoses of bilateral ischemic optic neuropathy--including infiltrative optic neuropathy and temporal arteritis--were exhaustively investigated in this patient.

Pseudotumor cerebri induced by danazol

Intracranial hypertension with papilledema occurred in two patients receiving danazol therapy for either cyclic neutropenia or immune hemolytic anemia. Results of clinical, laboratory, and neuroradiologic studies showed no apparent cause for the condition in Case 1 and the papilledema resolved one month after discontinuing danazol. Carotid angiography in Case 2 demonstrated cerebral venous sinus thrombosis; the papilledema showed gradual improvement after cessation of danazol. An additional seven cases of pseudotumor cerebri presumed secondary to danazol therapy have been reported to the Food and Drug Administration. The papilledema resolved in all seven cases soon after discontinuing danazol. A drug-induced complication should be suspected, and alternative therapy sought, in patients who develop intracranial hypertension associated with administration of danazol.