Audio-Vestibular Profile of COVID-19; Systematic Review and Meta-analysis.

Introduction: After more than a year of the COVID-19 pandemic, audio-vestibular problems have been reported as consequences. Several limited case report studies with different methodologies were published. This study aimed to describe the impact of COVID-19 on the auditory-vestibular system and communication problems in subjects with hearing impairment. Materials and Methods: The current systematic review was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guideline. PubMed, Web of Science, and Google Scholar were searched to find relevant articles using combined keywords. Results: Out of 26 final studies, 20 studies dealt with the effects of COVID-19 on the auditory and vestibular system, and six articles examined the COVID-19 effects on hearing-impaired people and patients. In these studies, dizziness (17.8%), tinnitus (8.1%), and vertigo (2.8%) were common symptoms. Most studies were case reports (42.30%), and in terms of quality, nine studies (34.61%) were in the suitable quality group. Conclusions: COVID-19 might cause auditory-vestibular system problems by directly affecting the structures or functions of the inner ear or by weakening the immune system. The need for taking preventive measures during the COVID-19 pandemic has caused communication and social challenges, particularly for people with hearing loss.

Effect of aging on saccular function.

BACKGROUND: Aging can cause loss of balance, which may lead to physical and psychological problems. As the role of the otolith organs in maintaining postural stability has been emphasized in recent years, the present study investigated the effect of aging on saccular function using cervical vestibular evoked myogenic potentials (cVEMP). METHODS: The participants were assigned into two groups; group one included 31 young adults with a mean age of 22.15 (range: 19-26 yr) and group two consisted of 31 old adults with a mean age of 69.76 years (range: 61-79 yr). All participants hearing sensitivity was normal with no history of balance problems. VEMP was recorded for all subjects using tone burst 500 Hz stimuli at the threshold level and 95 dB nHL intensity level through air-conduction stimulation via an insert receiver. RESULTS: There was a significant difference in the cVEMP response threshold (p< 0.001), P1 wave latency (p<0.001), P1/N1 amplitude (p< 0.001), and asymmetry ratio of P1/N1 amplitude (p< 0.05) between the two groups. No significant difference was found between the left and right ears or in N1 wave latency between the two groups. CONCLUSION: VEMP abnormalities observed in healthy older adults showed the sensitivity of this test in identifying early signs of vestibular dysfunction. VEMP is an easy-to-use test that requires a short time to be performed. Therefore, it can be used as a selective objective screening test to detect vestibular disorders.

Association analysis of intractable epilepsy with C3435T and G2677T/A ABCB1 gene polymorphisms in Iranian patients.

OBJECTIVE: The results from studies investigating a possible association between ABCB1 polymorphism and drug-resistant epilepsy are so far inconsistent. Moreover, recent meta-analyses studies do not confirm any link between ABCB1 C3435T polymorphism and drug resistance. Yet, if patients with comparable clinical status (same type of epilepsy, antiepileptic drugs, epilepsy onset and gender) are evaluated, the link between ABCB1 polymorphisms and drug resistance may be unmasked. We studied the association between C3435T and G2677T/A ABCB1 gene polymorphisms and drug resistance in Iranian epilepsy patients. METHODS: Two hundred healthy subjects and 332 epilepsy patients (200 drug-responsive and 132 drug-resistant) were selected. Genotypes were determined by polymerase chain reaction followed by restriction fragment length polymorphism or the amplification refractory mutation system. RESULTS: The risk of drug resistance was higher in patients with a C/T genotype than in those with C/C or T/T genotypes at position 3435 in patients with cryptogenic epilepsy (p=0.01). A higher risk of drug resistance was observed in adult patients with a C/C genotype than in those with a T/T genotype at position 3435 (25.8% vs 15.8%, p=0.01). The risk of drug resistance was also higher in female patients with a C/C genotype than in those with a T/T genotype at position 3435 (26.8% vs 16.3%, p=0.04). No significant association was found between G2677T/A polymorphism and epilepsy drug resistance in the different subgroups of patients. CONCLUSION: Iranian adult female patients with a C/C genotype at position 3435 of the ABCB1 gene have a higher risk of resistance to antiepileptic drugs. Replication studies with large sample sizes are needed to confirm the results.

Association between ABCB1-T1236C polymorphism and drug-resistant epilepsy in Iranian female patients.

BACKGROUND: One third of epileptic patients are resistant to several anti-epileptic drugs (AED). P-glycoprotein (P-gp) is an efflux transporter encoded by ATP-binding cassette subfamily B member 1 (ABCB1) gene that excludes drugs from the cells and plays a significant role in AEDs resistance. Over-expression of P-gp could be a result of polymorphisms in ABCB1 gene. We studied the association of T129C and T1236C single-nucleotide polymorphisms (SNP) of ABCB1 gene with drug-resistant epilepsy in Iranian epileptics. METHODS: DNA samples were obtained from 200 healthy controls and 332 epileptic patients, of whom 200 were drug responsive and 132 drug resistant. The frequencies of the genotypes of the two SNP were determined by polymerase chain reaction followed by restriction fragment length polymorphism. RESULTS: No significant association was found between T129C and T1236C genotypes and drug-resistant epilepsy neither in adults nor in children. However, the risk of drug resistance was higher in female patients with 1236CC (P = 0.02) or CT (P = 0.008) genotype than in those with TT genotype. The risk of drug resistance was also higher in patients with symptomatic epilepsies with 1236CC (P = 0.02) or CT (P = 0.004) genotype than in those with TT genotype. The risk of drug resistance was lower in patients with idiopathic epilepsies with 129TT genotype (P = 0.001) than in those with CT genotype. CONCLUSION: Our results indicate that T1236C polymorphism is associated with drug resistance in Iranian female epileptic patients. Replication studies with large sample sizes are needed to confirm our results.