Vestibular dysfunction in adult patients with osteogenesis imperfecta

The International Standard Set of Outcome Measures for the Assessment of Hearing in People with Osteogenesis Imperfecta

OBJECTIVE

The aim is to recommend a minimum standard set of clinician-reported outcome measures (CROMs) and patient-reported outcome measures (PROMs) on hearing for people with osteogenesis imperfecta (OI). This project is part of the larger "Key4OI" project initiated by the "Care4BrittleBones foundation" of which the goal is to improve quality of life of people with OI. Key4OI provides a standard set of outcome measures and covers a large set of domains affecting the well-being of people with OI.

METHODS

An international team of experts in OI, comprising specialists in audiological science, medical specialists, and an expert patient representative, used a modified Delphi consensus process to select CROMs and PROMs to evaluate hearing problems in people with OI. In addition, focus groups of people with OI identified key consequences of their hearing loss. These criteria were matched to categories of preselected questionnaires to select a PROM that matched their specific hearing-related concerns best.

RESULTS

Consensus on PROMs for adults and CROMs for adults and children was reached. The focus of the CROMs was on specific audiological outcome measures and standardized follow-up.

CONCLUSIONS

This project resulted in a clear consensus statement for standardization of hearing-related PROMs and CROMs and follow-up management of patients with OI. This standardization of outcome measurements will facilitate comparability of research and easier international cooperation in OI and hearing loss. Furthermore, it can improve standard of care in people with OI and hearing loss by incorporating the recommendations into care pathways.

Clinical manifestations of osteogenesis imperfecta in adulthood: An integrative review of quantitative studies and case reports

Osteogenesis imperfecta (OI) is a rare genetic disorder of the bones caused by a mutation in Type I collagen genes. As adults with OI are aging, medical concerns secondary to OI may arise. This integrative review sought to review, appraise, and synthesize the clinical manifestations faced by adults with OI. Four electronic bibliographic databases were searched. Published quantitative, qualitative, and mixed-methods studies, as well as case reports from 2000 to March 2019, addressing a clinical manifestation in adulthood, were reviewed. Eligible studies and case reports were subsequently appraised using the Mixed Methods Appraisal Tool and Case Report Checklist, respectively. Twenty quantitative studies and 88 case reports were included for review regardless of the varying methodological quality score. These studies collectively included 2,510 adults with different OI types. Several clinical manifestations were studied, and included: hearing loss, cardiac diseases, pregnancy complications, cerebrovascular manifestations, musculoskeletal manifestations, respiratory manifestations, vision impairment, and other clinical manifestations. Increased awareness may optimize prevention, treatment, and follow-up. Opportunities to enhance the methodological quality of research including better design and methodology, multisite collaborations, and larger and diverse sampling will optimize the generalizability and transferability of findings.

Management of Benign Paroxysmal Positional Vertigo in an Adult With Severe Osteogenesis Imperfecta

The purpose of this case report was to describe the evaluation and management of atypical benign paroxysmal positional vertigo (BPPV) in an adult with severe osteogenesis imperfecta. A 29-year-old male was referred to a physical therapist with extensive experience in vestibular rehabilitation who provided horizontal canal BPPV treatment with a canalith repositioning maneuver over two treatment sessions. The individual's symptoms had reduced by 65% and his nystagmus during the roll test was reduced. Extreme care is needed to safely reposition individuals living with severe osteogenesis imperfecta, but the repositioning can reduce symptoms and improve quality of life. Laryngoscope, 130:2241-2244, 2020.

Genetics of Tinnitus: Still in its Infancy

Tinnitus is the perception of a phantom sound that affects between 10 and 15% of the general population. Despite this considerable prevalence, treatments for tinnitus are presently lacking. Tinnitus exhibits a diverse array of recognized risk factors and extreme clinical heterogeneity. Furthermore, it can involve an unknown number of auditory and non-auditory networks and molecular pathways. This complex combination has hampered advancements in the field. The identification of specific genetic factors has been at the forefront of several research investigations in the past decade. Nine studies have examined genes in a case-control association approach. Recently, a genome-wide association study has highlighted several potentially significant pathways that are implicated in tinnitus. Two twin studies have calculated a moderate heritability for tinnitus and disclosed a greater concordance rate in monozygotic twins compared to dizygotic twins. Despite the more recent data alluding to genetic factors in tinnitus, a strong association with any specific genetic locus is lacking and a genetic study with sufficient statistical power has yet to be designed. Future research endeavors must overcome the many inherent limitations in previous study designs. This review summarizes the previously embarked upon tinnitus genetic investigations and summarizes the hurdles that have been encountered. The identification of candidate genes responsible for tinnitus may afford gene based diagnostic approaches, effective therapy development, and personalized therapeutic intervention.

Osteogenesis imperfecta: clinical diagnosis, nomenclature and severity assessment

Recently, the genetic heterogeneity in osteogenesis imperfecta (OI), proposed in 1979 by Sillence et al., has been confirmed with molecular genetic studies. At present, 17 genetic causes of OI and closely related disorders have been identified and it is expected that more will follow. Unlike most reviews that have been published in the last decade on the genetic causes and biochemical processes leading to OI, this review focuses on the clinical classification of OI and elaborates on the newly proposed OI classification from 2010, which returned to a descriptive and numerical grouping of five OI syndromic groups. The new OI nomenclature and the pre-and postnatal severity assessment introduced in this review, emphasize the importance of phenotyping in order to diagnose, classify, and assess severity of OI. This will provide patients and their families with insight into the probable course of the disorder and it will allow physicians to evaluate the effect of therapy. A careful clinical description in combination with knowledge of the specific molecular genetic cause is the starting point for development and assessment of therapy in patients with heritable disorders including OI. © 2014 The Authors. American Journal of Medical Genetics Published by Wiley Periodicals, Inc. This is an open access article under the terms of the Creative Commons Attribution–NonCommercial–NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Low bone mineral density is associated with balance and hearing impairments

PURPOSE

Bone demineralization affects the skeletal system, including the temporal bone, which contains the cochlea and the vestibular labyrinth. However, research on the association of bone mineral density (BMD) with balance and hearing sensitivity is limited with conflicting results. Therefore, we examined the relationship in a population representative sample.

METHODS

We analyzed 8863 participants to the National Health and Nutrition Examination Survey (1999-2004) aged 40 years and older. Total and head BMD were measured by dual energy x-ray absorptiometry. Balance was evaluated using the Romberg Test of Standing Balance on Firm and Compliant Support Surfaces condition 4, also indicative of vestibular dysfunction. Hearing condition was self-reported. The associations of total and head BMD with balance and hearing were assessed using multiple and multinomial logistic regressions adjusting for covariates.

RESULTS

On multiple logistic regression, low total BMD was associated with balance impairment (odds ratio [OR], 2.21; 95% confidence interval [CI], 1.43-4.75), especially in older adults (≥65 years old; OR, 3.72; 95% CI, 1.07-12.85). In multinomial regression, low total BMD was associated with report of significant hearing impairment in older adults (OR, 5.30; 95% CI, 1.20-23.26).

CONCLUSIONS

Low BMD is associated with balance and hearing impairments, especially in older adults.

Otologic and audiologic characteristics of children with skeletal dysplasia in central China

CONCLUSION

Otologic and audiologic abnormalities are both highly prevalent in Chinese children with skeletal dysplasias. Audiologic and otologic evaluations with medical intervention are recommended for these children.

OBJECTIVE

Children with skeletal dysplasia have a number of otolaryngologic issues including hearing loss. This study aimed to investigate the otologic and audiologic features of Chinese children with skeletal dysplasia in central China.

METHODS

Otologic evaluations and pure tone audiometry were performed in children with skeletal dysplasias. To explore the potential associations with hearing loss, we studied various craniofacial anomalies.

RESULTS

A total of 125 children (mean age 9.2 years, range 5-18 years) with skeletal dysplasia were enrolled, and otoscopic examination identified eardrum abnormalities in 45.6% of the children. Audiologic analysis revealed 14 cases (11.2%) with conductive hearing loss (CHL) and 22 cases (17.6%) with sensorineural hearing loss (SNHL).

New perspectives on osteogenesis imperfecta

A new paradigm has emerged for osteogenesis imperfecta as a collagen-related disorder. The more prevalent autosomal dominant forms of osteogenesis imperfecta are caused by primary defects in type I collagen, whereas autosomal recessive forms are caused by deficiency of proteins which interact with type I procollagen for post-translational modification and/or folding. Factors that contribute to the mechanism of dominant osteogenesis imperfecta include intracellular stress, disruption of interactions between collagen and noncollagenous proteins, compromised matrix structure, abnormal cell-cell and cell-matrix interactions and tissue mineralization. Recessive osteogenesis imperfecta is caused by deficiency of any of the three components of the collagen prolyl 3-hydroxylation complex. Absence of 3-hydroxylation is associated with increased modification of the collagen helix, consistent with delayed collagen folding. Other causes of recessive osteogenesis imperfecta include deficiency of the collagen chaperones FKBP10 or Serpin H1. Murine models are crucial to uncovering the common pathways in dominant and recessive osteogenesis imperfecta bone dysplasia. Clinical management of osteogenesis imperfecta is multidisciplinary, encompassing substantial progress in physical rehabilitation and surgical procedures, management of hearing, dental and pulmonary abnormalities, as well as drugs, such as bisphosphonates and recombinant human growth hormone. Novel treatments using cell therapy or new drug regimens hold promise for the future.

Basilar impression and osteogenesis imperfecta: a 21-year retrospective review of outcomes in 20 patients

Object

Basilar impression (BI) secondary to osteogenesis imperfecta (OI) is a rare but debilitating condition that is often progressive unless it is halted. More recently, ventral decompression surgery has been advocated for this condition. This study is a retrospective review of the 21-year experience of ventral decompression surgery and dorsal occipitocervical fixation in patients with BI secondary to OI and is the largest patient series reported to date.

Methods

Twenty patients treated between 1982 and 2003 by the senior author at the authors' institution were included in this study. All patients underwent ventral decompression surgery followed by dorsal craniocervical stabilization. Patients were followed up for a median of 10 years.

Results

There were no intraoperative or perioperative deaths. Postoperatively, 16 of 20 (80%) patients showed objective improvement or maintained their good preoperative level of function. After surgery, of the 15 patients admitted with Karnofsky Performance Scale (KPS) scores of 70% or less, 11 improved, two remained unchanged, one patient's condition deteriorated, and one patient died of an unrelated cause. Of five patients admitted with a KPS score of 80% or greater, no patient's condition deteriorated in the short- and midterm period, but one patient had recurrence 15 years after surgery. At the end of follow-up, 25% of the patients had recurrence of brainstem compression symptoms or had died, and 15% showed no improvement after surgery. All of the remaining patients (60%) had sustained a long-term benefit from surgery.

Conclusions

Aggressive ventral decompression surgery and dorsal stabilization for patients with BI secondary to OI can not only halt disease progression but can also produce a good and sustainable long-term functional outcome, even in those patients who present as severely symptomatic. Patients who presented early with minor symptoms had good long-term outcomes.

Cochlear implantation in 3 patients with osteogenesis imperfecta: imaging, surgery and programming issues

Osteogenesis imperfecta (OI) is a heterogeneous disease of the connective tissue caused by a defective gene that is responsible for the production of collagen type I, leading to defective bone matrix and connective tissue. Hearing loss affects 35-60% of the patients and will progress to deafness in 2-11% of OI patients for whom cochlear implantation may become the only remaining treatment option. Three patients with OI were retrieved from the Nijmegen Cochlear Implant Centre's database. Most of the specific observations in ear surgery on patients with OI, such as brittle scutum, sclerotic thickening of the cochlea, hyperplastic mucosa in the middle ear and persistent bleeding, were encountered in these 3 patients. In case 3, with severe deformities on the CT scan, misplacement of the electrode array into the horizontal semicircular canal occurred. In all 3 cases, programming was hindered by nonauditory stimulation. Even after reimplantation, nonauditory sensations lead to case 3 becoming a nonuser. Averaged electrode voltages in case 3 were deviant in accordance with an abnormally conductive otic capsule. Spatial spread of neural excitation responses in cases 1 and 2 suggested intracochlear channel interaction for several electrodes, often in combination with facial nerve stimulation (FNS). In case 1, the estimated pitch of the electrodes that caused FNS varied consistently. Despite the electrophysiological changes, after 1-year follow-up, open set phoneme scores of 81% and 78% were reached in cases 1 and 2, respectively. When aware and prepared for the specific changes of the temporal bone in OI, cochlear implantation can be a safe and feasible procedure. Preoperative imaging is recommended to be fully informed on the morphology of the petrosal bone. In case of severe deformities on the CT scan, during counseling the possibility of misplacement should be mentioned. Rehabilitation is often hindered by FNS requiring frequent refitting.

Skull base abnormalities in osteogenesis imperfecta: a cephalometric evaluation of 54 patients and 108 control volunteers

Object

Osteogenesis imperfecta (OI), which usually results from mutations in type I collagen genes, causes bone fragility and deformities. The head is often abnormally shaped, and changes in skull base anatomy in the form of basilar impression and basilar invagination have been reported. The authors analyzed the skull base anatomy on standardized lateral cephalograms from 54 patients with OI (Types I, III, and IV) and 108 control volunteers. They were surprised to find that the previously used diagnostic measures for basilar abnormality in patients with OI were exceeded in 6.5 to 7.4% of the controls, and hence needed to be reevaluated.

Methods

The authors calculated the distance from the odontoid process to four reference lines, including a novel one, in the controls. The normal mean distances were exceeded by more than two standard deviations (SDs) in 28.3 to 35.2%, and by more than three SDs in 13.2 to 16.6% of the patients with OI. The latter figures reliably reflect the prevalence of basilar impression. As a sign of basilar invagination the odontoid process protruded into the foramen magnum or reached the foramen magnum level in 22.2% of the patients with OI, whereas none of the controls showed this feature. Platybasia (an anterior cranial base angle > 146°) was present in 11.1% of the patients but in none of the controls.

Conclusions

Platybasia, basilar impression, and basilar invagination were often coexpressed, but each was also present as an isolated abnormality. These three abnormalities and wormian bones were predominantly found in OI Types III and IV as well as in patients exhibiting dentinal abnormality.

Lack of correlation between the type ofCOL1A1orCOL1A2mutation and hearing loss in osteogenesis imperfecta patients

Osteogenesis imperfecta (OI) is caused by mutations in COL1A1 and COL1A2 that code for the alpha1 and alpha2 chains of type I collagen. Phenotypes correlate with the mutation types in that COL1A1 null mutations lead to OI type I, and structural mutations in alpha1(I) or alpha2(I) lead to more severe OI types (II-IV). However, correlative analysis between mutation types and OI associated hearing loss has not been previously performed. A total of 54 Finnish OI patients with previously diagnosed hearing loss or age 35 or more years were analyzed here for mutations in COL1A1 or COL1A2. Altogether 49 mutations were identified, of which 41 were novel. The 49 mutations represented the molecular genetic background of 41.1% of the Finnish OI population. A total of 38 mutations were in COL1A1 and 11 were in COL1A2. Of these, 16 were glycine substitutions and 16 were splicing mutations in alpha1(I) or alpha2(I). In addition, 17 null allele mutations were detected in COL1A1. A total of 32 patients (65.3%) with a mutation had hearing loss. That is slightly more than in our previous population study on Finnish adults with OI (57.9%). The association between the mutation types and OI type was statistically evident. Patients with COL1A1 mutations more frequently had blue scleras than those with COL1A2 mutations. In addition, patients with COL1A2 mutations tended to be shorter than those with COL1A1 mutations. However, no correlation was found between the mutated gene or mutation type and hearing pattern. These results suggest that the basis of hearing loss in OI is complex, and it is a result of multifactorial, still unknown genetic effects.

Stapes surgery in osteogenesis imperfecta in Finland

We present the surgical findings and audiometric results of ear surgery performed between 1961 and 2002 on 33 Finnish patients (43 operations) with osteogenesis imperfecta (OI). The mean age at the time of the first operation was 30.1 years. The typical surgical findings were a thick, fixed, or obliterated footplate, thick and vascular mucosa with an excessive tendency to bleed, and elastic, fractured, or atrophic stapes crura. As compared with previous studies, the hearing gain was poorer and the remaining postoperative gap was greater for the 43 operations analyzed. The results of this nationwide study, however, may not be directly comparable with operative results of non-population studies. On the other hand, the hearing gain in our study was better in university hospitals than in central hospitals and, furthermore, was comparable with that of previous studies after surgery performed by a single surgeon in a university hospital. Conductive hearing loss related to OI may be successfully treated with surgery in most patients. The rarity of the disease, leading to small annual numbers of operations, the variable surgical findings, and the profuse bleeding tendency of the middle ear, as well as the audiometric results in this study, support centralization of ear surgery in OI patients.