Variants of posterior semicircular canal involvement in benign paroxysmal positional vertigo

Benign paroxysmal positional vertigo is the most common cause of peripheral vertigo. It is characterized by short and recurrent episodes of vertigo, trigged by specific head movements that displace otoconia within the semicircular canals. The movement of dislodge otoconia from the utricle cause abnormal positional endolymphatic currents. Primary treatment involves reposition maneuvers aimed at moving the displaced otoconia out the affected canal, therefore correct identification of the affected canal is essential for the diagnosis. The posterior semicircular canal (PSC) is the most frequently affected due to its spatial orientation and the force of gravity. Recent technological advances have allowed for better assessment of positional nystagmus during diagnostic and therapeutic maneuvers, revealing various possible scenarios of PSC involvement. Regarding the PSC, otoconia may be found in different parts of the canal, and not just in the expected location, floating in the long arm of the canal. The understanding of these variants is crucial, as the prognosis and the disease progression differ in such cases. This review aims to describe the six possible variants of PSC involvement described so far.

Seizure prophylaxis in meningiomas: a systematic review and meta-analysis

INTRODUCTION

No formal indication currently exists for seizure prophylaxis in neurosurgical oncology patients. Neither have specific recommendations been made on the use of antiepileptic drugs (AED) in seizure-free patients with meningiomas scheduled for surgery. AEDs are generally prescribed on a discretionary basis, taking into consideration a range of clinical and radiological risk factors. We present a systematic review and meta-analysis exploring the effectiveness of antiepileptic prophylaxis in patients with meningioma and no history of seizures.

METHODS

We performed a systematic review of the PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Embase, and clinicaltrials.gov databases. Of a total of 4368 studies initially identified, 12 were selected for extraction of data and qualitative analysis. Based on the clinical data presented, we were only able to include 6 studies in the meta-analysis. We performed heterogeneity studies, calculated a combined odds ratio, evaluated publication bias, and conducted a sensitivity analysis.

RESULTS

AED prophylaxis in patients with meningioma and no history of seizures did not significantly reduce the incidence of post-operative seizures in comparison to controls (Mantel-Haenszel combined odds ratio, random effects model: 1.26 [95% confidence interval, 0.60-2.78]; 2041 patients). However, we are unable to establish a robust recommendation against this treatment due to the lack of prospective studies, the presence of selection bias in the studies reviewed, the likelihood of underestimation of seizure frequency during follow-up, and the strong influence of one study on the overall effect.

CONCLUSIONS

Despite the limitations of this review, the results of the meta-analysis do not support the routine use of seizure prophylaxis in patients with meningioma and no history of seizures.

Seizure prophylaxis in meningiomas: A systematic review and meta-analysis

INTRODUCTION

No formal indication currently exists for seizure prophylaxis in neurosurgical oncology patients. Neither have specific recommendations been made on the use of antiepileptic drugs (AED) in seizure-free patients with meningiomas scheduled for surgery. AEDs are generally prescribed on a discretionary basis, taking into consideration a range of clinical and radiological risk factors. We present a systematic review and meta-analysis exploring the effectiveness of antiepileptic prophylaxis in patients with meningioma and no history of seizures.

METHODS

We performed a systematic review of the PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Embase, and clinicaltrials.gov databases. Of a total of 4368 studies initially identified, 12 were selected for extraction of data and qualitative analysis. Based on the clinical data presented, we were only able to include 6 studies in the meta-analysis. We performed heterogeneity studies, calculated a combined odds ratio, evaluated publication bias, and conducted a sensitivity analysis.

RESULTS

AED prophylaxis in patients with meningioma and no history of seizures did not significantly reduce the incidence of post-operative seizures in comparison to controls (Mantel-Haenszel combined odds ratio, random effects model: 1.26 [95% confidence interval, 0.60-2.78]; 2041 patients). However, we are unable to establish a robust recommendation against this treatment due to the lack of prospective studies, the presence of selection bias in the studies reviewed, the likelihood of underestimation of seizure frequency during follow-up, and the strong influence of one study on the overall effect.

CONCLUSIONS

Despite the limitations of this review, the results of the meta-analysis do not support the routine use of seizure prophylaxis in patients with meningioma and no history of seizures.

Atypical manifestations of hepatitis A virus infection

Acute hepatitis due to the hepatitis A virus usually has a short, benign and self-limited course, without causing chronic hepatitis. However, some cases have an atypical presentation, such as relapsing hepatitis, prolonged or persistent cholestasis, fulminant hepatic failure, or liver failure associated with autoimmune hepatitis. The typical clinical course of acute hepatitis A virus infection is spontaneous remission in 90% of the cases, but atypical cases have a prevalence that varies from less than 1 to 20%, depending on the manifestation (overall prevalence ∼7%). There is little information on the atypical clinical courses of hepatitis A virus infection and the lack of recognizing those presentations in clinical practice often results in carrying out numerous studies and treatments that not only are unnecessary, but can also be harmful. The aim of the present article was to describe 3 clinical cases of atypical hepatitis A infection and provide a literature review of such cases.