Doxycycline and intracranial hypertension

Doxycycline-Induced Intracranial Hypertension Presenting as Unilateral Pulsatile Tinnitus

Background

Pulsatile tinnitus (PT) is increasingly recognized as a cardinal symptom of idiopathic intracranial hypertension (IIH). However, clinicians should remain aware of other causes of nonidiopathic or secondary intracranial hypertension manifesting as PT. We present 2 patients with isolated PT (without accompanying headache, blurred vision, and papilledema) thought to be secondary to tetracycline-induced intracranial hypertension. To our knowledge, these are the first cases of PT as the presenting symptom of this condition.

Cases

A 41-year-old female (body mass index [BMI] 29 kg/m2) with ocular rosacea was initially treated with minocycline. Shortly after transitioning to oral doxycycline and erythromycin eye ointment, she noted left-sided PT. Her PT resolved after discontinuing doxycycline. In a second case, a 39-year-old female (BMI 19 kg/m2) with acne presented with a three-year history of left-sided PT while on long-term oral doxycycline for many years. She denied visual or auditory changes and atypical headaches. MRI findings were concerning for intracranial hypertension. Three months later, the patient was seen by neuro-ophthalmology, with findings suggesting prior papilledema. The patient reported PT improvement after discontinuing doxycycline.

Conclusions

This case series highlights 2 cases of isolated PT as the sole symptom of intracranial hypertension that resolved with tetracycline cessation. The presentation and unexpected improvement following tetracycline discontinuation are atypical compared with previous reports of tetracycline-induced intracranial hypertension. Clinicians should maintain a high index of suspicion for all types of intracranial hypertension (idiopathic and secondary), even in patients with a lower BMI. Current and prior medications should be reviewed when considering the etiology of intracranial hypertension.

Increased Incidence of Pseudotumor Cerebri Syndrome Among Users of Tetracycline Antibiotics

BACKGROUND

To determine whether the use of a tetracycline-class antibiotic is associated with an increased risk of developing pseudotumor cerebri syndrome (PTCS).

METHODS

We identified patients in the University of Utah Health system who were prescribed a tetracycline-class antibiotic and determined what percentage of those individuals were subsequently diagnosed with PTCS secondary to tetracycline use. We compared this calculation to the number of patients with PTCS unrelated to tetracycline use.

RESULTS

Between 2007 and 2014, a total of 960 patients in the University system between the ages of 12 and 50 were prescribed a tetracycline antibiotic. Among those, 45 were diagnosed with tetracycline-induced PTCS. We estimate the incidence of tetracycline-induced PTCS to be 63.9 per 100,000 person-years. By comparison, the incidence of idiopathic intracranial hypertension (IIH) is estimated to be less than one per 100,000 person-years (Calculated Risk Ratio = 178).

CONCLUSIONS

Although a causative link between tetracycline use and pseudotumor cerebri has yet to be firmly established, our study suggests that the incidence of pseudotumor cerebri among tetracycline users is significantly higher than the incidence of IIH in the general population.

Papilledema Secondary to Neurologic Lyme Borreliosis: A Meta-Case Series

BACKGROUND

Papilledema can be a manifestation of neurologic Lyme borreliosis (LB). The clinical manifestations and progression of these cases have not been comprehensively documented to date. We aimed to describe clinical and diagnostic features and to assess patient outcomes in cases of papilledema secondary to neurologic LB.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Database from inception to August 2019. We did not restrict our search by study design or by publication date, status, or language.

RESULTS

Twenty-eight studies describing 46 cases of papilledema secondary to neurologic LB were included. Common clinical features included cranial neuropathy (68%) and diplopia (61%). Most patients did not recall tick bite (71%) and were afebrile (74%). Brain imaging was normal in 64% cases. Cerebrospinal fluid analysis showed lymphocytic pleocytosis (77%). Initial treatment with intravenous ceftriaxone was given in 52% of cases and resulted in a 100% resolution rate. Concomitant treatment with acetazolamide resulted in favorable outcomes.

CONCLUSIONS

For patients in endemic regions who describe symptoms suggestive of intracranial hypertension and papilledema, especially accompanied by facial nerve palsy and other cranial nerve palsies, underlying neurologic LB should be considered.

Diagnosis of idiopathic intracranial hypertension - the importance of excluding secondary causes: A systematic review

BACKGROUND

Idiopathic intracranial hypertension is characterized by increased intracranial pressure without any pathological findings on neuroimaging, except for signs of high intracranial pressure. Before diagnosing idiopathic intracranial hypertension secondary causes of increased intracranial pressure should be excluded.

OBJECTIVE

to characterize the phenotype of patients with secondary intracranial hypertension and to identify possible risk factors for secondary intracranial hypertension.

METHODS

We have systematically searched the PubMed database. The publications were analyzed according to the patient phenotype, age, gender, comorbidities, body mass index/weight status, and additional medication. The results are summarized in four categories: medication, infection, hormonal induced intracranial hypertension and miscellaneous groups of diseases related to sIH.

RESULTS

We identified 105 eligible papers which included 272 cases. There were 49.6% pediatric cases. Among the adult group,70.9% were women. A total of 40.4% of all cases were obese or overweight, 27% among adults and 13.4% among pediatric cases. Increased BMI and recent weight gain, anemia, renal diseases and hypertension were the most frequent comorbidities related to sIH.

CONCLUSION

Among sIH patients, 40.4% were obese or overweight; two thirds were women. We recommend that even patients with a typical IIH phenotype should be screened for secondary causes.

A Systematic Review of Basic Science and Animal Studies on the Use of Doxycycline to Reduce the Risk of Posttraumatic Osteoarthritis After Anterior Cruciate Ligament Rupture/Transection

BACKGROUND

Posttraumatic osteoarthritis (PTOA) after injury to the anterior cruciate ligament (ACL) is common.

PURPOSE

To perform a systematic review of basic science and animal studies to determine the effect of doxycycline treatment on the prevention of PTOA after ACL rupture/transection.

STUDY DESIGN

Systematic review.

METHODS

A systematic review was performed by searching the PubMed, Cochrane Library, and Embase databases to identify basic science and animal studies evaluating the effect of doxycycline treatment on the prevention of PTOA of the knee joint after ACL/cranial cruciate ligament (CCL) injury. The search phrase used was "doxycycline cruciate ligament." Inclusion criteria were basic science and animal studies evaluating the effect of oral administration of doxycycline in ACL/CCL-deficient animals with or without a control group.

RESULTS

Seven studies met inclusion criteria and were included in this systematic review. Five studies were performed in dogs, 1 in rabbits, and 1 in mice. Overall, the effects of doxycycline treatment on the prevention of PTOA after ACL/CCL rupture/transection were mixed. In dogs, no significant effects of doxycycline treatment were found in terms of matrix metalloproteinase (MMP) activity, while a mouse study found significantly lower MMP-13 expression on the tibia in doxycycline-treated animals, suggesting that doxycycline may protect against proteoglycan loss and decrease osteoarthritis progression. Cartilage nitric oxide concentrations were lower in doxycycline-treated dogs compared with untreated dogs, suggesting decreased cartilage degradation among doxycycline-treated dogs, although there were no significant effects on cartilage stromelysin levels with no significant effects in terms of physiological remodeling or catabolism of cartilage. Bone formation or resorption was not found to be affected by doxycycline treatment. One study demonstrated a substantial beneficial effect of doxycycline on gross morphology of the medial femoral condyle. Doxycycline was found to conserve bone strain energy density and appeared to limit subchondral bone loss in 1 study.

CONCLUSION

Based on the limited available animal studies, doxycycline appears to demonstrate some benefits in the prevention of PTOA after ACL/CCL rupture/transection. Additional studies are needed to further characterize the potential benefits, side effects, dosage, and duration of this treatment after ACL injury in human patients.

A Comparison Between the Clinical Features of Pseudotumor Cerebri Secondary to Tetracyclines and Idiopathic Intracranial Hypertension

PURPOSE

Comparisons between clinical features of tetracycline-induced pseudotumor cerebri (PTC-T) and those of idiopathic intracranial hypertension (IIH) are absent in the literature. We hypothesized that significant clinical differences between these etiologies exist and could be better understood by retrospective analysis.

DESIGN

Retrospective cohort study.

METHODS

We reviewed patients diagnosed with pseudotumor cerebri syndrome (PTCS) at our center and identified those who developed PTC-T after treatment with a tetracycline-class antibiotic and those with IIH. Groups were compared by demographics, body mass index, ophthalmic examination, treatment, clinical course, and visual outcomes.

RESULTS

We identified 52 cases of PTC-T and 302 cases of IIH. Obesity rates were significantly different (43.8% for PTC-T vs 79.2% for IIH, P < .001). The mean age at diagnosis was younger for PTC-T (19.8 years vs 28.1 years for IIH, P < .001). Diplopia was more common with PTC-T (40.4% vs 20.1% for IIH, P = .001). The mean illness duration was shorter for PTC-T (18.3 weeks vs 62.9 weeks for IIH, P <.0001). Recurrence rates were significantly different (4.0% for PTC-T vs 16.5% for IIH, P <.001). The frequency of surgical intervention was similar. Vision loss was uncommon but occurred with similar frequency.

CONCLUSION

We identified significant clinical differences but also identified important similarities between the 2 groups. There appear to be nonobese patients who develop PTC-T, discontinue the antibiotic, and never develop PTCS again. There are other patients who develop PTC-T, discontinue the antibiotic, and later develop IIH. We conclude that PTC-T represents a spectrum of disease in susceptible individuals.

Drug-Induced Intracranial Hypertension: A Systematic Review and Critical Assessment of Drug-Induced Causes

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a condition with increased intracranial pressure of unknown etiology. Its presenting symptoms include persistent headache, pulsatile tinnitus, and visual obscuration. It tends to occur in obese women of childbearing age, and its greatest risk is irreversible loss of vision. Some of the commonly used medications in dermatology, especially those for acne vulgaris, have been associated with IIH. However, the creation of specific risk categories for drugs as a guide for clinicians has never been performed.

OBJECTIVE

The aim of this study was to critically assess all published cases of IIH and identify high-risk drugs associated with drug-induced intracranial hypertension (DIIH), to assist dermatologists and other physicians with patient education and monitoring of symptoms of secondary intracranial hypertension.

METHODS

MEDLINE, EMBASE, and Cochrane Review Databases were searched for all cases of IIH thought to be drug-related between January 1900 and June 2019. A total of 5117 articles were identified, and 235 articles were found to be relevant. All cases were assessed to satisfy the modified Dandy criteria for diagnosis of IIH, and the likelihood of each case being a 'definite' adverse drug reaction (ADR) was determined using the Koh algorithm for ADR. An association category (from weakly associated [Category I] to strongly associated [Category V]) was assigned based on the number of cases meeting these two criteria.

RESULTS

There were 259 verifiable cases of DIIH. Vitamin A derivatives, tetracycline-class antibiotics, recombinant growth hormone, and lithium were found to be most strongly associated with DIIH (Categories IV and V). Corticosteroids were moderately associated with DIIH (Category III). Drugs that were weakly associated with DIIH (Categories I and II) include cyclosporine, progestin-only contraceptives, combined oral contraceptives, second- and third-generation fluoroquinolones, sulfenazone, gonadotropin-releasing hormones and luteinizing hormone-releasing hormone agonist, nalidixic acid, amiodarone, stanozolol, danazol, divalproic acid, sulfasalazine, ketoconazole, and ustekinumab.

CONCLUSION

We suggest using the term 'drug-induced intracranial hypertension' (DIIH) and propose a set of diagnostic criteria for DIIH. Our review attempts to identify DIIH-associated drugs based on a strict diagnostic and drug-causality algorithm, then stratify them into appropriate risks categories. This may ultimately assist physicians in counselling patients about the risk of DIIH when prescribing medications and recognizing this uncommon yet sight-threatening condition.

The role of intracranial pressure in glaucoma and therapeutic implications

Despite glaucoma being the second leading cause of blindness globally, its pathogenesis remains incompletely understood. Although intraocular pressure (IOP) contributes to glaucoma, and reducing IOP slows progress of the disease, some patients progress despite normal IOP (NTG). Glaucomatous damage causes characteristic cupping of the optic nerve where it passes through the lamina cribrosa. There is evidence that cerebrospinal fluid (CSF) within the optic nerve sheath has a different composition from CSF surrounding the brain. Furthermore, fluctuations in CSF flow into the optic nerve sheath may be reduced by trabeculae within the sheath, and on standing intracranial pressure (ICP) within the sheath is stabilised at around 3 mmHg due to orbital pressure. Blood pressure has been linked both to glaucoma and ICP. These facts have led some to conclude that ICP does not play a role in glaucoma. However, according to stress formulae and Laplace's Law, stress within the lamina cribrosa is dependent on the forces on either side of it, (IOP and ICP), and its thickness. On lying flat at night, ICP between the brain and optic nerve sheath should equalise. Most evidence suggests ICP is lower in glaucoma than in control groups, and that the lamina cribrosa is thinner and more posteriorly displaced in glaucoma. Subjects who have had ICP reduced have developed signs of glaucoma. This review finds most evidence supports a role for low ICP in the pathogenesis of glaucoma. Caffeine, theophylline and vitamin A may increase ICP, and could be new candidates for an oral treatment.

Contemporary management of the pseudotumor cerebri syndrome

Introduction: Diagnosis and appropriate management of patients with the pseudotumor cerebri syndrome are imperative to prevent or minimize permanent visual loss and headache-related disability. Areas covered: Steps in management, including making the correct diagnosis, techniques to assess the patient's visual status, medical treatment of intracranial hypertension and the associated headaches, weight management strategies, surgical treatments and stenting are reviewed incorporating the most recent medical evidence. Expert opinion: As the pathogenesis of the pseudotumor cerebri syndrome is still unknown, many of the currently employed management strategies incorporate a 'plumbing approach' to decrease cerebrospinal fluid (CSF) pressure. The Idiopathic Intracranial Hypertension Trial (IIHTT) taught us that the disorder markedly affects visual and overall quality of life, and that reducing pressure alone is not enough to make patients well, even those considered to have 'mild' vision loss. Other than the IIHTT, the evidence supporting the use of various treatments is meager. The course of the disorder can be unpredictable, and the clinician(s) managing these patients are often uncertain about which treatments to employ. Moreover, the desired modalities and specialists are not universally available in all locations. An individualized and detailed approach to the various manifestations and nuances of the disorder is essential.

Headaches Due to Low and High Intracranial Pressure

PURPOSE OF REVIEW

Headache disorders attributed to low and high intracranial pressure are commonly encountered in specialty headache practices and may occur more frequently than realized. While the headaches resulting from intracranial pressure disorders have what are conventionally thought of as defining characteristics, a substantial minority of patients do not manifest the "typical" features. Moreover, patients with intracranial pressure disorders may also have a preexisting primary headache disorder. Heightening the complexity of the presentation, the headaches of intracranial pressure disorders can resemble the phenotype of a primary disorder. Lastly, patients with so-called intracranial "hypotension" often have normal CSF pressure and neuroimaging studies. Thus, a high index of suspicion is needed. The published literature has inherent bias as many types of specialists evaluate and treat these conditions. This article reviews the key points to emphasize the history, examination, and laboratory evaluation of patients with intracranial pressure disorders from a neurologist's perspective.

RECENT FINDINGS

Lumbar puncture opening pressure in patients with spontaneous intracranial hypotension was low enough to meet diagnostic criteria (≤60 mm CSF) in only 34% of patients in one study. Most patients had an opening pressure in the low normal to normal range, and 5% had an opening pressure of 200 mm CSF or more. Diskogenic microspurs are a common cause of this syndrome. The Idiopathic Intracranial Hypertension Treatment Trial found that most participants had a headache phenotype resembling migraine or tension-type headache. No "typical" or characteristic headache phenotype was found, and headache-related disability was severe at baseline. Headache disability did not correlate with the lumbar puncture opening pressure at baseline or at the 6-month primary outcome period. Although participants who were randomly assigned to acetazolamide had a lower mean CSF opening pressure at 6 months, headache disability in that group was similar to the group who received placebo.

SUMMARY

Significant overlap is seen in the symptoms of high and low CSF pressure disorders and in those of primary headache disorders. Neurologists are frequently challenged by patients with headaches who lack the typical clinical signs or imaging features of the pseudotumor cerebri syndrome or spontaneous intracranial hypotension. Even when characteristic symptoms and signs are initially present, the typical features of both syndromes tend to lessen or resolve over time; consider these diagnoses in patients with long-standing "chronic migraine" who do not improve with conventional headache treatment. While the diagnostic criteria for pseudotumor cerebri syndrome accurately identify most patients with the disorder, at least 25% of patients with spontaneous intracranial hypotension have normal imaging and over half have a normal lumbar puncture opening pressure. Detailed history taking will often give clues that suggest a CSF pressure disorder. That said, misdiagnosis can lead to significant patient morbidity and inappropriate therapy.

Doxycycline in the management of sexually transmitted infections

Doxycycline is a second-generation tetracycline, available worldwide for half a century. It is an inexpensive broad-spectrum antimicrobial agent largely used in the management of several bacterial infections, particularly involving intracellular pathogens, as well as in the treatment of acne or for the prophylaxis of malaria. Physicochemical characteristics of doxycycline (liposolubility) allow a high diffusion in the tissues and organs. It has high bioavailability and a long elimination half-life allowing oral administration of one or two daily doses. Over the last decade, the prevalence of bacterial sexually transmitted infections (STIs) (syphilis, chlamydiosis, gonorrhoea and Mycoplasma genitalium infections) has increased in most countries, mainly in MSM, many of whom are infected with HIV. In light of increasing prevalence of resistance towards first-line regimens of some STI agents and recently updated recommendations for STI management, doxycycline appears to be an attractive option compared with other available antibiotics for the treatment of some STIs due to its efficacy, good tolerability and oral administration. More recently, indications for doxycycline in STI prophylaxis have been evaluated. Considering the renewed interest of doxycycline in STI management, this review aims to update the pharmacology of, efficacy of, safety of and resistance to doxycycline in this context of use.

A Population-Based, Case-Control Evaluation of the Association Between Hormonal Contraceptives and Idiopathic Intracranial Hypertension

PURPOSE

To determine if the use of oral contraceptive pills (OCP) and other hormonal contraceptives are associated with a higher incidence of idiopathic intracranial hypertension (IIH).

DESIGN

Retrospective, population-based, case-control study.

METHODS

Setting: Female IIH patients evaluated between January 1, 1990, and December 31, 2016 were identified using the Rochester Epidemiology Project (REP), a record-linkage system of medical records for all patient-physician encounters among Olmsted County, Minnesota, residents.

STUDY POPULATION

Fifty-three female residents of Olmsted County diagnosed with IIH between 15 and 45 years of age. The use of OCPs and other hormonal contraceptives was compared to controls matched for age, sex, and body mass index. Interventions/Exposures: Hormonal contraceptives.

MAIN OUTCOME MEASURE

Odds of developing IIH.

RESULTS

Of the 53 women diagnosed with IIH between 15 and 45 years of age, 11 (20.8%) had used hormonal contraceptives within ≤30 days of the date of IIH diagnosis, in contrast to 30 (31.3%) among the control patients. The odds ratio of hormonal contraceptive use and IIH was 0.55 (95% conficence interval [CI]: 0.24-1.23, P = .146). The odds ratio of OCP use was 0.52 (95% CI: 0.20-1.34, P = .174).

CONCLUSIONS

OCP and other hormonal contraceptives were not significantly associated with a higher incidence of IIH, arguing against the need for women with IIH to discontinue their use.

MMP-2: is too low as bad as too high in the cardiovascular system?

Matrix metalloproteinase (MMP)-2 cleaves a broad spectrum of substrates, including extracellular matrix components (responsible for normal tissue remodeling) and cytokines (modulators of the inflammatory response to physiological insults such as tissue damage). MMP-2 expression is elevated in many cardiovascular pathologies (e.g., myocardial infarction, hypertensive heart disease) where tissue remodeling and inflammatory responses are perturbed. Thus, it has generally been assumed that blockade of MMP-2 activity will yield therapeutic effects. Here, we provide a counterargument to this dogma based on 1) preclinical studies on Mmp2-null ( Mmp2−/−) mice and 2) clinical studies on patients with inactivating MMP2 gene mutations. Furthermore, we put forward the hypothesis that, when MMP-2 activity falls below baseline, the bioavailability of proinflammatory cytokines normally cleaved and inactivated by MMP-2 increases, leading to the production of cytokines and cardiac secretion of phospholipase A2activity into the circulation, which stimulate systemic inflammation that perturbs lipid metabolism in target organs. Finally, we suggest that insufficient understanding of the consequences of MMP-2 deficiency remains a major factor in the failure of MMP-2 inhibitor-based therapeutic approaches. This paucity of knowledge precludes our ability to effectively intervene in cardiovascular and noncardiovascular pathologies at the level of MMP-2.

Comparison of the Efficacy of Azithromycin Versus Doxycycline in Acne Vulgaris: A Meta-Analysis of Randomized Controlled Trials

Background

Acne vulgaris is one of the most common disorders of the pilosebaceous unit. Although doxycycline is considered to be a first-line anti-acne antibiotic, various other antibiotics have been tried due to its adverse effects and contraindications. We performed a meta-analysis of randomized controlled trials (RCTs) that compared the efficacy of oral azithromycin pulse therapy with that of oral daily doxycycline in the management of moderate to severe acne vulgaris.

Methods

Five scientific databases (MEDLINE, EMBASE, Cochrane Library, SCOPUS, and Web of Science) were searched to identify relevant studies. A review of 1,341 publications produced six RCTs that met our predefined inclusion criteria. The clinical outcome measures were remaining acne lesion counts, patients' self-assessment of treatment, and the investigators' assessment of treatment after 12 weeks.

Results

We included six studies assessing 906 patients with moderate to severe acne vulgaris. Meta-analyses of clinical outcome measures revealed no significant difference between the two groups regarding remaining acne lesion counts (p=0.27), patients' self-assessment of treatment (p=0.67), and the investigators' assessment of treatment (p=0.32). The incidence of severe adverse events leading to the discontinuation of therapy was higher in the doxycycline daily therapy group when compared with the azithromycin pulse therapy group.

Conclusion

This study indicates that azithromycin pulse therapy is equivalent to doxycycline at 12 weeks in the efficacy of the treatment for moderate to severe acne vulgaris Therefore, oral azithromycin pulse therapy may be a good alternative to doxycycline in the management of acne for those unable to tolerate doxycycline.

Pseudotumor Cerebri Syndrome with Resolution After Discontinuing High Vitamin A Containing Dietary Supplement: Case Report and Review

A 24-year-old non-obese, but slightly overweight, female presented with a two-week history of progressive severe headache associated with two days of blurry vision. Clinical exam was significant for bilateral papilledema and an enlarged blind spot on visual field testing. Contrast enhanced MRI head revealed no space occupying lesion. A lumbar puncture revealed an elevated opening pressure of 38 cm H₂O with normal cerebrospinal fluid composition leading to a diagnosis of pseudotumor cerebri syndrome (PTCS). The patient lacked the typical risk factors of high body mass index or obvious antecedent medications; however, on subsequent questioning, she was chronically ingesting a high vitamin A containing weight loss dietary supplement (Thrive W® - Table 1), which we believe had caused intracranial hypertension. Discontinuation of the diet pill and treatment with acetazolamide led to marked improvement of her PTCS. This case highlights the fact that non-traditional products or medications with high vitamin A may cause pseudotumor cerebri, which treating physicians should assess for while dealing with non-obese PTCS patients.

Safety of antimalarial medications for use while scuba diving in malaria Endemic Regions

Background

Recreational diving occurs annually in areas of the world where malaria is endemic. The safety and efficacy of antimalarials for travelers in a hyperbaric environment is unknown. Of particular concern would be medications with adverse effects that could either mimic diving related illnesses such as barotrauma, decompression sickness (DCS) and gas toxicities, or increase the risk for such illnesses.

Methods

We conducted a review of PubMed and Cochrane databases to determine rates of neurologic adverse effects or other effects from antimalarials that may be a problem in the diving environment.

Results

One case report was found on diving and mefloquine. Multiple case reports and clinical trials were found describing neurologic adverse effects of the major chemoprophylactic medications atovaquone/proguanil, chloroquine, doxycycline, mefloquine, and primaquine.

Conclusions

Of the available literature, atovaquone/proguanil and doxycycline are most likely the safest agents and should be preferred; atovaquone/proguanil is superior due to reduced rates of sunburn in the marine environment. Primaquine also appears to be safe, but has reduced efficacy against P. falciparum; mefloquine possesses the highest rate of neurologic side effects and therefore these agents should be limited to extreme cases of patients intolerant to other agents. Chloroquine appears unsafe in the hyperbaric environment and should be avoided. More studies are required to include database reviews of returned divers traveling to malaria endemic areas and randomized controlled trials in the hyperbaric environments.

Oral fluoroquinolones and risk of secondary pseudotumor cerebri syndrome: Nested case-control study

OBJECTIVE

To quantify the risk of secondary pseudotumor cerebri syndrome (PTCS) with fluoroquinolones.

METHODS

A case-control study of people 15-60 years of age from the LifeLink Database (QuintilesIMS, Parsippany, NJ) was conducted. Cases had the first ICD-9-CM code for benign intracranial hypertension (BIH) as well as having received a procedure code for an MRI or CT scan and a lumbar puncture within 15 days or 30 days of the BIH code. For each case, 10 controls were selected using density-based sampling. Current users of fluoroquinolones received a prescription within 15 days or 30 days of the date of the diagnosis. For the sensitivity analysis, risk periods for 30 and 60 days were also examined. Adjusted rate ratios (RRs) were computed from a conditional logistic regression model.

RESULTS

From a cohort of 6,110,723 people, there were 339 cases of PTCS and 3,390 corresponding controls. In the primary analysis, the adjusted RR for current users of fluoroquinolones for both the 15-day and 30-day definitions were 5.67 (95% confidence interval [CI] 2.72-11.83) and 4.15 (95% CI 2.29-7.50), respectively. The risk with tetracycline antibiotics was also increased, with RRs for 15 and 30 days of current use of 2.68 (0.89-8.11) and 3.64 (1.67-7.91), respectively.

CONCLUSION

Our study suggests an increase in the risk of PTCS with current users of fluoroquinolones. Although this adverse event is rare, patients who experience symptoms of raised intracranial pressure including headaches, tinnitus, and double vision while taking fluoroquinolones should seek medical attention.

Pediatric Intracranial Hypertension

Primary (idiopathic) intracranial hypertension has been considered to be a rare entity, but with no precise estimates of the pediatric incidence in the United States. There have been attempts to revise the criteria over the years and adapt the adult criteria for use in pediatrics. The clinical presentation varies with age, and symptoms tending to be less obvious in younger individuals. In the prepubertal population, incidentally discovered optic disc edema is relatively common. By far the most consistent symptom is headache; other symptoms include nausea, vomiting tinnitus, and diplopia. Treatment mainstays include weight loss when appropriate and acetazolamide. Furosemide may exhibit a synergistic benefit when used in conjunction with acetazolamide. Surgical interventions are required relatively infrequently, but include optic nerve sheath fenestration and cerebrospinal fluid shunting. Pain and permanent vision loss are the two major complications of this disorder and these manifestations justify aggressive treatment. Once intracranial hypertension has resolved, up to two thirds of patients develop a new or chronic headache type that is different from their initial presenting headache.

Safety Considerations and Monitoring in Patients Treated with Systemic Medications for Acne

Acne vulgaris, a disorder of the pilosebaceous unit, is one of the most commonly encountered conditions in dermatology practice. Effective treatment of acne vulgaris is important in that it can prevent psychosocial distress and physical scarring. Systemic therapeutic options are available for moderate to severe acne. It is imperative that the safe and effective treatment revolves around the health care provider's familiarity of side effects of various treatments. In this article, the side effects and monitoring guide for the most commonly prescribed systemic agents for acne vulgaris are reviewed.

Lyme disease-related intracranial hypertension in children: clinical and imaging findings

Lyme disease (LD) is a tick-borne infection that is endemic to multiple areas of the United States. Patients with LD may present with sign and symptoms of intracranial hypertension (IH). The objective of this study is to evaluate the history, clinical findings, CSF analysis, and brain imaging results in pediatric patients with increased intracranial pressure secondary to LD. A retrospective database search was performed using the International Classification of Diseases (ICD) 9/10 codes to identify patients diagnosed with LD and IH between 2004 and 2014 at a tertiary referral pediatric hospital. Clinical, laboratory and neuroimaging data for each patient were reviewed. Seven patients met inclusion criteria; mean age was 9.6 years (standard deviation 4.0 years); 4/7 patients were male. Average body mass index was 18.8 kg/m(2) (standard deviation 3.0 kg/m(2)). Fever was present in four patients. Four had a history of LD related erythema migrans. All had elevated CSF opening pressure with leukocytosis and lymphocytic predominance. MRI obtained in six patients showed contrast enhancement of various cranial nerves. Tentorial enhancement was noted in all patients. In addition, patients had widening of the optic nerve sheath (ONS), optic nerve protrusion, and flattening of the posterior globe consistent with increased intracranial pressure. All patients had resolution of their symptoms after initiation of antibiotic therapy. In endemic areas, LD should be included in the differential of IH. MRI can help distinguish IH due to LD from its idiopathic form due to the presence of tentorial and cranial nerve enhancement in the former in addition to abnormal CSF showing leukocytosis with lymphocyte predominance.

Idiopathic intracranial hypertension

Background

Idiopathic intracranial hypertension or pseudotumour cerebri is primarily a disorder of young obese women characterised by symptoms and signs associated with raised intracranial pressure in the absence of a space-occupying lesion or other identifiable cause.

Summary

The overall incidence of idiopathic intracranial hypertension is approximately two per 100,000, but is considerably higher among obese individuals and, given the global obesity epidemic, is likely to rise further. The pathophysiology of this condition is poorly understood, but most theories focus on the presence of intracranial venous hypertension and/or increased cerebrospinal fluid outflow resistance and how this relates to obesity. A lack of randomised clinical trials has resulted in unsatisfactory treatment guidelines and although weight loss is important, especially when used in conjunction with drugs that reduce cerebrospinal fluid production, resistant cases remain difficult to manage and patients invariably undergo neurosurgical shunting procedures. The use of transverse cerebral sinus stenting remains contentious and long-term benefits are yet to be determined.

Conclusion

An understanding of the clinical features, diagnostic work-up and therapeutic options available for patients with idiopathic intracranial hypertension is important both for neurologists and ophthalmologists as visual loss maybe permanent if untreated.

Digoxin as a treatment for patients with idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH)-sometimes called pseudotumor cerebri-is a neurologic condition distinguished by any of the following symptoms: headache, increased cerebrospinal fluid pressure, papilledema, vision loss, diplopia, tinnitus, deafness, nausea and vomiting, or sixth nerve palsy. Medical and surgical management options are available for patients with IIH. The authors report a case of IIH that was successfully resolved with digoxin after standard avenues of therapy were exhausted.

Headache medicine meets neuro-ophthalmology: exam techniques and challenging cases

The neuro-ophthalmology examination is critical to anyone who sees patients with the common symptom of headache. By examining the visual acuity, pupils, visual fields, motility, and fundus, clues to both secondary causes of headache and primary headaches exist. In this review, we discuss how to do the neuro-ophthalmology examination and we review cases of primary and secondary headache where key features of the examination assisted in making the correct diagnosis.

Doxycycline-Induced Cutaneous Inflammation with Systemic Symptoms in a Patient with Acne Vulgaris

Background:

Doxycycline is a commonly prescribed antibiotic for the treatment of acne vulgaris. Often preferred to other tetracyclines due to a safer and milder side-effect profile, doxycycline is more frequently prescribed as a treatment of this common condition.

Objective:

To present a case report of a young patient who developed skin eruptions over the extremities; myalgias; fatigue; swelling involving the face, hands, and feet; headache; and mood changes after 2 years of using doxycycline. She promptly developed similar symptoms after a rechallenge with doxycycline 1 year later.

Results/Conclusion:

This important finding will make practitioners more vigilant to the side effects of this medication despite its current safety profile and regardless of the time that a patient is using it.

Pseudotumor cerebri and ciprofloxacin: a case report

Introduction

We present a case of ciprofloxacin-associated pseudotumor cerebri in a 22-year-old African American woman. Withdrawal of ciprofloxacin in our patient resulted in complete resolution of ciprofloxacin-associated pseudotumor, as evidenced by a normal neuro-ophthalmic examination and a cerebrospinal fluid opening pressure of 140 mmH20.

Case presentation

A 22-year-old African American woman presented with a headache of two weeks duration, visual blurring and horizontal diplopia after starting ciprofloxacin for pyelonephritis. An ophthalmic examination revealed that she had left eye esotropia, and a picture of the fundus demonstrated bilateral disc swelling without spontaneous venous pulsations. Magnetic resonance imaging of the brain and a magnetic resonance venogram were normal. A diagnostic lumbar puncture demonstrated an elevated opening pressure of 380mmH2O in a supine position. Laboratory examinations, including a cerebrospinal fluid exam, were unremarkable.

Conclusion

ciprofloxacin-associated pseudotumor can cause chronic disabling headache and visual complications. Therapy is sub-optimal, often symptomatic, insufficient and complicated by side effects. When ciprofloxacin-associated pseudotumor presents in an atypical population, an inciting agent must be suspected because prompt withdrawal of the agent may lead to complete resolution of symptoms and prevent recurrence of similar episodes.

Minocycline-associated pseudotumor cerebri with severe papilledema

Background. Pseudotumor cerebri is an acknowledged but unusual complication of oral minocycline use. Vision loss and papilledema have been described as mild and transient, and some authors suggest that treatment is not needed. Methods. Case series of 2 patients with severe papilledema and visual field loss. Results. Severe pseudotumor cerebri developed in 2 nonobese patients taking minocycline. Their disease required further treatment even upon drug discontinuation because of visual field loss and papilledema. Conclusions. Minocycline-associated pseudotumor cerebri is not always a self-limited condition and may require aggressive medical or surgical management.

Doxycycline-chloroquine vs. doxycycline-placebo for malaria prophylaxis in nonimmune soldiers: a double-blind randomized field trial in sub-Saharan Africa

Failures of malaria chemoprophylaxis have been related to a lack of compliance with doxycycline due to its short elimination half-life. Adding a molecule with a long half-life to doxycycline could be useful to take over from this drug in case of occasional missed doses. A double-blind, placebo-controlled randomized field trial was designed to compare the tolerability of a doxycycline-chloroquine combination vs. doxycycline as malaria prophylaxis among French soldiers deployed in Africa. Data from 936 volunteers were analyzed. In both groups, the proportion of volunteers who reported at least one adverse effect was about 57%. Tolerability was similar in the groups except for a higher proportion of nausea or vomiting in the doxycycline-chloroquine group. The reported compliance rate was 86.6% and was similar in the two groups. Eight Plasmodium falciparum malaria cases were diagnosed in the doxycycline group and seven in the doxycycline-chloroquine group. The efficacy of the two chemoprophylaxis regimens was similar. Our study was the first randomized field trial to assess a doxycycline-chloroquine combination as malaria prophylaxis and showed no significant decrease of overall tolerability of the combination compared with doxycycline alone. Our results showed that a doxycycline-chloroquine combination could be a safe combination for malaria chemoprophylaxis.

Safety and Efficacy Review of Doxycycline

Doxycycline is a member of the tetracycline class of antibiotics and has been used clinically for more than 40 years. It is a well-tolerated drug that is bacteriostatic and acts via the inhibition of bacterial ribosomes. It is generally given at a dose of 100-mg daily or twice daily. It is well absorbed and has generally good tissue penetration. The serum half-life is 18-22 hours and dosage does not need to be adjusted in the presence of renal or hepatic impairment. Major side effects are gastro-intestinal and dermatological and it is generally contra-indicated in pregnancy or childhood because of concerns about discolouration of developing teeth and potential effects on growing bones. Drug interactions are not common although can occur with the concomitant use of methotrexate and the oral contraceptive pill, and its absorption can be reduced by the co-administration with some antacids and iron preparations. It has activity against many organisms, including Gram-positives, Gram-negatives and atypical bacteria. In addition, it appears to have some potentially clinically useful anti-inflammatory properties.

Doxycycline-induced pseudotumor cerebri

Tetracyclines are a commonly prescribed medication for the treatment of acne vulgaris that are associated with pseudotumor cerebri (PTC). With doxycycline specifically, however, the incidence of PTC is very rare. A patient was using oral doxycycline and topical retinoids for acne, and within two months she developed PTC. This case illustrates that despite the rarity of doxycycline-induced PTC, patients and physicians should be aware of this possibility. Furthermore, in the setting of new-onset headaches or visual changes, early ophthalmologic examination for papilledema is recommended for early diagnosis.

Resolution of an anterior-inferior cerebellar artery feeding aneurysm with the treatment of a transverse-sigmoid dural arteriovenous fistula

A 27-year-old man developed an unruptured anterior-inferior cerebellar artery (AICA) feeding aneurysm from a transverse-sigmoid dural arteriovenous malformation. The patient, with a known history of left transverse and sigmoid sinus thrombosis, presented with pulse-synchronous tinnitus. Angiography revealed an extensive dural arteriovenous fistula (AVF), with feeders from both the extracranial and intracranial circulations, involving the right transverse sinus, the torcula, and the left transverse/sigmoid sinuses. Multimodal endovascular and open surgical therapy was used to manage the lesion. Before a planned second-stage treatment for the left sigmoid sinus component, the dural AVF improved significantly. During this interval, however, a small flow-related aneurysm developed on the left AICA feeding the petrous dural region. The aneurysm resolved after resection of the involved sigmoid sinus. This is the first reported case of an unruptured feeding-artery aneurysm in an intracranial dural AVF that resolved spontaneously with treatment of the dural AVF. Until more is known about the natural history, the decisions of when and whether to treat an unruptured dural AVF feeding-artery aneurysm must be made on an individual basis.

Medication-induced intracranial hypertension in dermatology

Pseudotumor cerebri (PTC) is a syndrome of intracranial hypertension that is idiopathic or from an identified secondary cause. It is characterized by headaches and visual manifestations. The hallmark of PTC is papilledema and the feared consequence is visual loss that may be severe and permanent. The idiopathic form generally occurs in obese women of childbearing age. Various medications may produce PTC in patients at any age, including children. Several medications used in dermatology, particularly those used in the treatment of acne vulgaris, are associated with PTC. There is a strong association with tetracycline usage. Minocycline and doxycycline have also been linked to PTC, although there are relatively few reported cases. PTC has also been described with retinoids, including vitamin A (retinol) and isotretinoin. Although corticosteroids are often used to lower intracranial pressure acutely, corticosteroid withdrawal after long-term administration may induce increased intracranial pressure. A high index of suspicion, early diagnosis and treatment generally yield a good prognosis.