Libyan Cochlear Implant Programme

Reappraisal of the Libyan Cochlear Implant Programme

Declaration

“ Plagiarism is the usage, without equal recognition, of the rational work of another individual in work submitted for appraisal ”

I hereby acknowledge that I have read and understand the above definition of plagiarism. I declare that all stuff from other beginnings used in this piece of assessed work, whether straight quoted or paraphrased, has been clearly identified and attributed to the beginning from which it came by agencies of a footer or endnote mention, and that the University militias the right to execute plagiarism cheques on all informations and that this will be done indiscriminately on all class stuffs.

Recognitions

I would wish to show my sincere gratitude and thanks for the support and advice of the undermentioned people, without whom this survey would non hold been possible:

Dr Anwar Esriti (Consultant ENT SuRgeon & A ; Head of ENT Department, Tripoli Medical Centre) for oversing me throughout my elected period ; Dr Samia El-Ogbi( Specialist Registrar inENT )and Dr Asia Ehituish( Specialist Registrar in ENT )for their aid and aid on roll uping informations ; and the ENT section for their sort cordial reception and aid throughout my clip in Libya.

Abstraction

Cochlear nidation ( CI ) has become an constituted worldwide as a safe and effectual method of audile rehabilitation in selected badly and profound deaf kids and grownups. Over 100,000 patients have received cochlear implants worldwide and kids are emerging as the largest group to profit. The Libyan cochlear implant programme was set up in 2004. Data relating to the patients who received cochlear nidation between the October 2007 and January 2010 were studied. A sum of 30 seven implant operations were performed on 30 seven patients. All patients received Med-El SONATATI100 devices. Thirty-four ( 91.9 % ) of these patients were kids, whilst three ( 8.1 % ) were grownups. Combined, inborn hearing loss ( 54.1 % ) and perinatal/neonatal ( 29.7 % ) were the two chief aetiological factors in kids. Sixteen patients ( 43.2 % ) were born to blood related parents. The overall rate of child and major complications was 16.2 % . The purpose of this paper is to depict the experiences and advancement of the cochlear implant in Libya in add-on to the tendencies and the initial results of the programme.

Background

Hearing damage is a wide term used to depict the loss of hearing in one or both ears. Hearing impairment refers to finish or partial loss of the ability to hear from one or both ears. The degree of damage can be mild, moderate, terrible or profound. The footings hearing loss refers to the complete loss of ability to hear from one or both ears ( WHO Deafness and hearing damage ) . The World Health Organisation ( WHO ) estimate that 278 million people worldwide suffer from terrible to profound hearing loss in both ears. Additionally, the figure of people enduring from hearing loss will lift proportionately due to the turning universe population ( WHO Deafness and hearing damage ) . The WHO suggests that 50 % of hearing loss and hearing damage is evitable through early bar, diagnosing and direction ( WHO Deafness and hearing damage ) .

Social and economic load of hearing loss

Hearing damage and hearing loss are serious disablements that can enforce a heavy societal and economic load on persons, households, communities and states. Children with hearing impairment frequently experience delayed development of address, linguistic communication and cognitive accomplishments, which may ensue in slow acquisition and trouble progressing in school. In grownups, hearing damage and hearing loss frequently make it hard to obtain, execute, and maintain employment. As a consequence, kids and grownups may endure from societal stigmatisation and isolation as a consequence of hearing damage. ( Smith WHO 2001 ; REFERENCE )

Hazard Factors for Deafness ( Lecture Notes, Diseases of the Ear, Nose and Throat 10th edition and Smith WHO 2001 )

1. Inherited causes ( syndromic and non-syndromic )
2. Intrauterine exposure to infections ( e.g. German measles, CMV infection, toxoplasmosis, pox, Herpes simplex )
3. Perinatal and neonatal factors ( e.g. birth asphyxia or hypoxia, birth injury, A icterus, A due to Rhesus mutual exclusiveness )
4. Bacterial meningitis ( neonatal and postpartum )
5. Infectious diseases ( e.g. rubeolas, epidemic parotitiss, HIV and Lyme Disease )
6. Ototoxic drugs ( aminoglycoside antibiotics ( e.g. streptomycin, Garamycin ) , antimalarials ) .
7. Trauma, chiefly head hurt or hurt to the ear can do hearing damage.

Classs of hearing damage

Appraisal of Hearing Loss

Hearing can be cassessed in a figure of ways. Initially, clinical trials such as otoscopy, free field voice proving, Rinne ‘s trial and Weber ‘s trial are normally sufficient in placing hearing loss and possible causes. ( PICTURE OF RINNE ‘S and WEBER ‘S )

More advanced signifiers of proving are required to place the degree of hearing loss. One such trial that can measure a patient ‘s hearing threshold is the audile brain-stem response ( ABR ) . The ABR is one constituent of auditory evoked potencies which is recorded from electrodes attached to assorted locations on the caput. The ABR consists of a series of seven moving ridges happening within about 10 msecs after stimulus oncoming. It is by and large accepted that the ABR is generated by the auditory nervus and subsequent fiber piece of lands and karyon within the audile brain-stem tracts ( Head and Neck Surgery, Otolaryngology, 4th edition, Byron J Bailey, Jonas T. Johnson, Vol.2 Page 1901-2 )

The ABR is generated by a click stimulation, as it yields the clearest response. In a clinical scene, the ABR can be used to gauge audile sensitiveness in add-on to otoneurological appraisal.

Types of Hearing Loss

Hearing damage may be classified by manner of acquisition as familial or acquired and by the clip of oncoming as prelingual ( inborn ) or postlingual ( late oncoming ) ( Ballenger ‘s Manual of Otolaryngology and Head and Neck Surgery ) .A

Conductive hearing loss ( CHL ) is due to any job in the outer or in-between ear, which prevents sound moving ridges from making the interior ear ( Borgstein ENT ) . Sensorineural hearing loss ( SNHL ) is the consequence of a defect or harm in the interior ear or auditory ( Borgstein ENT ) . ( Table I )

Introduction

Cochlear nidation ( CI ) has become established worldwide as a safe and effectual intercession for audile rehabilitation of selected badly and profound deaf kids and grownups with sensorineural hearing loss ( Khan et al. 2007 ; Collins et Al. 1997 ) . Cochlear nidation permits the implant receiver to reintegrate with the hearing universe ( Muhaimeed et. al 2009 ) . Its efficaciousness, safety and dependability are good recognised ( Khan et al. 2007 ) . Over 100,000 patients have received cochlear implants worldwide and kids are emerging as the largest group to profit ( Khan et al. 2007 ) . Surveies have revealed that the bulk of CI users, with a prelingual or postlingual oncoming of hearing loss, obtain important benefit from this prosthetic device ( Nijmegen paper 1997 ) . This makes the cochlear implant arguably the most successful nervous prosthetic device in the history of medical specialty ( Muhaimeed et al. 2009 )

Cochlear implants seek to replace a non-functional inner ear hair cell transducer system by change overing mechanical sound energy into electrical signals that can be delivered to the cochlear nervus ( besides auditory or acoustic nervus ) in deeply deaf patients. The indispensable constituents of a cochlear implant system are a mike, which picks up acoustic information and converts it into electrical signals ; an externally worn address processor that processes the signal harmonizing to a predefined scheme ; and a surgically deep-rooted electrode array that is in the cochlea near the auditory nervus. Transmission of the electrical signal across the tegument from the external unit to the deep-rooted electrode array is most normally accomplished by the usage of electromagnetic initiation. ( Reference ) . The implant provides a direct stimulation of the coiling ganglion cells of the cochlear nervus short-circuiting the damaged hair cells ( Kandogan et.al 2005 ) . Visualize

Libya is a developing North African state with an estimated population of 6,420,000 ( Libya Health Information Centre ) . Tripoli is the capital metropolis of the Libya situated in the northwest coastline of the state. Tripoli Medical Centre ( TMC ) is a public infirmary with about 1450 beds, 1000 doctors and about 3000 employees ( Hospital website ) . The infirmary provides its services to a important figure of the population. In add-on to the dwellers of Tripoli, patients from across Libya nowadays to TMC due to its expertness, installations and degree of attention. Tripoli Medical Centre is the exclusive establishment in Libya that installs cochlear implants.

The Libyan cochlear implant programme was set up in 2004. Prior to the development of the programme, patients preponderantly travelled to Europe every bit good as neighboring Arab states such as Egypt and Jordan for cochlear nidation. However, due to significant fiscal deductions of medical attention and going among many other factors, really few patients could afford the costs of surgery, aftercare and rehabilitation.

The purpose of this paper is to depict the experiences and advancement of the cochlear implant in Libya in add-on to the tendencies and the initial results of the programme.

Methods

The Libyan Cochlear Implant Programme ( LCIP ) was set up in 2004 with the purpose of supplying its services to the kids and grownups of the state, enduring from hearing damages and hearing loss. There were no lower limit or maximal age bounds for referral and assessment.A

Datas associating to the patients who received cochlear nidation between the October 2007 and January 2010 were studied. Data relating to patients who were implanted from 2004 to 2007 were unavailable. A sum of 37 implant operations were performed on 37 patients. Patient records available the clip of the survey included age of patient at nidation, twelvemonth of nidation, topographic point of birth, diagnosing taking to hearing loss, neonatal and medical history, pre-operative probes ( Computed Tomography ( CT ) and Magnetic Resonance Imaging ( MRI ) ) , pre-operative audiology trials and any post-operative complications.

Choice Standards

In order to obtain good consequences, it is by and large reported that careful capable choice is necessary and that a rehabilitation programme should follow cochlear nidation ( Nijmegen paper 1997 ) .A The procedure of choosing suited campaigners for cochlear nidation requires medical, audiological and psychological rating ( Nijmegen paper 1997 ) .

So far, no individual pre-operative factor has been found that can foretell the result of cochlear nidation ( Nijmegen paper 1997 ) . However, it is common cognition that some biographical factors such as age at oncoming of hearing loss, continuance and type of hearing loss ( prelingual or postlingual hearing loss ) every bit good as age of nidation no uncertainty play a important function ( Nijmegen paper 1997 ; Muhaimeed et al. 2009 ; Khan et Al. 2003 ) .

The multi-disciplinary influence in cochlear implant rating allows for an exchange of information between the sawbones and other members of the implant and rehabilitation procedure, including audiologists, societal workers, and psychologists.

To get down with, the patient is referred to a cochlear implant Centre, and initial contact is made. The patient may foremost be seen and identified as an implant campaigner by an audiologist. Then they are seen by the sawbones in order to measure the patients for fittingness for surgery every bit good as sing if there any contra-indications to nidation. A everyday ENT scrutiny is performed on all of the patients taking portion in the programme.

Campaigning of patients taking portion in the LCIP focused chiefly on their general wellness and aetiology of hearing loss, in add-on to the patient and their household ‘s committedness to post-operative rehabilitation. In maintaining with old surveies ( Kandogan et al. 2005 ) , A the LCIP presently accepted minimal age for nidation is two old ages

Audiology appraisal

Audiological appraisal of each campaigner was performed pre-operatively to find suitableness of the patient for surgery. Such proving would corroborate profound, bilateral sensorineural hearing loss, without utile residuary hearing ( Nijmegen paper 1997 ) . Data received pre-operatively are a valuable resource for agencies of comparing with post-implant tonss ( Nijmegen paper 1997 ) .A

ABR testing of all the patients was done pre-operatively to… … … … … … … … …

Due to fiscal deductions associated with developing a cochlear implant programme in a underdeveloped state, station operative hearing testing was really limited. Presently, the lone hearing appraisals done after nidation include. Ideally,

Radiological Appraisal

Pre-operative radiological appraisal of all the patients taking portion in the LCIP included high declaration computed imaging ( HRCT ) every bit good as a magnetic resonance imagination ( MRI ) scan. These radiological scans are an indispensable requirement in order to measure the cochlear anatomy and patency, to define surgical entree, and to help the pick of which ear is best to engraft ( Gleeson et.al 2003 ) .

CT straight images the temporal bone constructions while at the same time imaging the soft tissues of the cochlea and its milieus. Besides, CT is utile at placing a narrow internal auditory meatus, which has been associated with an absent vestibulocochlear nervus ( Silberman 1995 ; Mueller et.al 1989 ; Gleeson et.al 2003 )

MRI is considered a superior mode at visualising cochlear fluid leting a much more accurate thought sing cochlear patency. The semicircular canals, the cerebello-pontine angle and the vestibulocochlear nervus are more easy identified on MRI ( Arriage MA, Carrier 1996 ; Gleeson 2003 )

However, some contention surrounds the affair of which type of imaging mode is most suited for pre-operative appraisal. A recent survey ( Gleeson et.al 2003 ) , suggests that the usage of either imaging method entirely were non superior to the other, and each manner of imagination was sufficient plenty to place any abnormalcies at the clip of surgery. However, the usage of both modes, as with the LCIP, is utile in finding the most suited side of nidation, therefore avoiding any surgical troubles. ( Gleeson et.al 2003 )

Surgical attack

From the beginning of the programme, the classical surgical technique for cochlear nidation has been used on all. The chief stairss in this attack include a post-auricular ‘C ‘ molded scratch normally made 1cm from the planned site of the receiving system. The pericranium is raised with the tegument flap in order to keep good vascular supply, as mentioned in old surveies ( Nijmegen 1997 ) . Afterwards a cortical mastoidectomy is performed and a bed ( cadaverous good ) was drilled for the receiver-stimulator unit ( Hehar et al. 2002 ) . Posterior tympanotomy is so carried out, followed by cochleostomy, which has been enthusiastically adopted by cochlear implant sawboness as it provides good entree to the unit of ammunition window and headland ( Kronenberg et al. 2001 ) . Care and preciseness is taken non to misidentify hypotympanic cells for the unit of ammunition window niche in order to right infix the electrode array in the scala kettle, in order to forestall what is considered an unacceptable complication ( Nijmegen 1997 ) .

Complications of cochlear implant surgery include wound infection, post-operative giddiness and sickness, In an effort to understate the incidence of complications, Kronenberg and co-workers ( Kronenberg et al. 2001 ) depict an alternate attack which involves come ining the in-between ear through a suprameatal attack ( SMA ) short-circuiting the mastoid pit. Harmonizing to their survey, this surgical attack shortens the continuance of the process to about one hr instead than the standard two hours. The survey besides reports that their technique minimises complications as it prevents possible hurt by direct injury or bore overheating of the chorda kettle or facial nervousnesss ( Kronenberg et al. 2001 ) .

All patients taking portion in the programme received a multi-channel cochlear implant ( SONATATI100, MED-EL, Innsbruck, Austria ) . Based on studies of meningitis following cochlear nidation, the bulk from the USA ( SA paper mention ) ; all pediatric patients taking portion in the LCIP were given pre and post-operative contraceptive antibiotics against Diplococcus pneumoniae and H.influenzae.

Cochlear nidation has been recognised as a safe intercession ( Muhaimeed et al. 2009, Khan et al. 2007 ) . However, as with any type of surgery, it possesses the hazard of child and major complications ( Collins et Al. 1997 ) . A major complication is defined as one taking to explantation or re-implantation, decease of a patient, or remain in infirmary in surplus of one hebdomad. A minor complication is defined as self-limiting, or improves with conservative direction ( Muhaimeed et al. 2009, Collins et Al. 1997 ) .

Post-operative switch on and adjustment was performed four hebdomads after the surgery. Each patient received single auditory and communications accomplishments developing which is incorporated in their rehabilitation programme.

Consequences

Since the beginning of the LCIP, a sum of 37 nidations have been performed on 37 patients ( Figure 1 ) . Four of these operations ( 10.8 % ) were performed in 2007, 12 ( 32.4 % ) in 2008, nineteen ( 51.4 % ) in 2009 and two ( 5.4 % ) up and till February 2010. All patients received MED-EL SONATATI100 devices. Thirty-four ( 91.9 % ) of these patients were kids ( male, 19 ; female, 15 ) . Whilst three grownups ( 8.1 % ) were installed with implants, of which two were male and one female. Thirty-two ( 86.5 % ) patients received implants in their right ear, whilst five ( 13.5 % ) patients were implanted in their left ear. Seventeen ( 45.9 % ) patients received cochlear implants before the age of five. Of this subgroup, nine ( 52.9 % ) were male and eight ( 47.1 % ) were female. The average age of pediatric patients taking portion in the programme was 3.4 old ages.

This survey revealed that 20 ( 54.1 % ) of patients presented with inborn hearing loss as the primary aetiology of their hearing loss ( Table ) . Other aetiologies included meningitis, maternal German measles, progressive disease and perinatal/neonatal ( including prematureness, preeclampsia, birth asphyxia, meconium aspiration, feverish paroxysms and maternal German measles ) . Thirty-five patients ( 94.6 % ) presenting to programme were diagnosed with sensorineural hearing loss ( SNHL ) . Two patients ( 5.4 % ) who were diagnosed with audile neuropathy were referred for cochlear nidation and will be officially reviewed in the treatment.

As antecedently mentioned, three patients taking portion in the programme were grownups. Two of these patients had progressive aetiologies doing their profound hearing loss. One patient had a cerebrovascular accident which so led to their deteriorating hearing. This patient unluckily died a few months/years after being implanted. The 2nd and 3rd… … … … …

Records of each patients hearing thresholds were besides reviewed ( Table ) . As classified by the WHO, all patients were classified as holding profound hearing damage ( 81dB or greater in better ear ; AW Smith 2001 ) . Eighteen patients ( 48.7 % ) were recorded to hold ABR up to 90dB, 14 ( 37.8 % ) with ABR of up to 100dB, four ( 10.8 % ) up to 105dB and one patient with an ABR of up to 110dB. Three station linguistic patients, all of whom were grownups, received tympanometry proving. Two patients were tested utilizing otoacoustic emanations, due to their unnatural ABR in maintaining with their diagnosing of auditory neuropathy.

Data collected in this survey besides included the hometown of each patient. 14 patients ( 37.8 % ) presented from Tripoli, 4 patients ( 10.8 % ) each from Benghazi and Al-Zawya, 2 patients ( 5.4 % ) each from Al-Bayda, Kikla, Ghriyan, Misrata and Subrata and a patient ( 2.7 % ) each from Al-Azizia, Ghat, Al-Zahra, Mselata and Zletan ( Figure )

Seventeen patients ( 45.9 % ) had a positive history of hearing loss in the household. Sixteen patients ( 43.2 % ) had blood related parents, 13 had parents whom were 1st grade cousins ( 35.1 % ) , one patient ( 2.7 % ) with parents whom were 2nd grade cousins and two patients ( 5.4 % ) whom parents were 3rd degree cousins. 21 patients ( 56.8 % ) had parents whom were non related Of the 17 patients with a household history of hearing loss, 11 patients ( 64.7 % ) had parents related to the 1st grade, two ( 11.8 % ) with 3nd grade related parents and four patients ( 23.5 % ) with parents non blood related. While in comparing, patients with a negative household history of hearing loss, two patients ( 10 % ) had parents related to the 1st grade, one ( 5 % ) with 2nd grade related parents and 17 patients ( 85 % ) with parents non blood related.

The overall incidence of post-operative complications was 16.2 per cent. There were minor complications in three patients ( 8.1 % ) , all of whom had a hematoma environing the implant happening within the first hebdomad of surgery. In two of these patients, their hematoma resolved spontaneously, while the 3rd patient had his hematoma aspirated and all recovered without incidence. Two patients ( 5.4 % ) were re-implanted due to damaged implants which were performed in 2004. However, due to… … … … … … … … … … ..During the programme, merely one patient ( 2.7 % ) developed CSF gusher which is considered as a major complication. This complication was managed by mending… …

Discussion

There are studies of meningitis following cochlear nidation, the bulk from the USA ( Muhaimeed et al. 2009 ) . Post-operative meningitis was non observed in any of the patients. All pediatric patients were vaccinated against Diplococcus pneumoniae and H.influenzae. The bulk of our deep-rooted patients were kids ( 91.9 % ) and their average age at nidation was 3.4 old ages. 54.1 % of patients presented with inborn hearing loss which is comparable to other studies ( Muhaimeed et al. 2009 ) . The incidence of sensorineural hearing loss among kids in Libya today is still unknown and requires farther research.

A figure of surveies have shown that first-class consequences are executable every bit good as accomplishable in pre-lingual patients when a cochlear implant is received before the age of three without surgical complications or functional tuning troubles ( SA paper ; Kandogan et Al. 2005 ; Hehar et Al. 2002 ) . The coveted purpose of the LCIP, certainly every bit good as other cochlear programmes, is to engraft younger pre-lingual kids every bit shortly as possible, finally even during the first twelvemonth of life from a neuro-developmental point of position ( Kandogan et al. 2005 ) . This construct nevertheless, in world is dependent on a figure of factors.

Early designation of high hazard patients is necessary, peculiarly patients with a positive household history. This issue has so far been dealt with good in Libya, of all time since the debut of the cochlear implant programme. Extensive media coverage of the programme on local telecasting has encouragingly raised consciousness about hearing loss and the cochlear implant programme among the general populace. First, this has lead to quicker presentation of patients whom complain of hearing loss. Second, this has lowered the thresholds of households in coming frontward with their kids with delayed hearing development. Third, it gave members of the multi-disciplinary squad an chance to step in at an earlier phase and offer rehabilitation Oklahoman than what was normally possible

Neonatal showing of hearing loss until now has yet to be officially set up in Libya. The affair of testing is multi-factorial and is dependent on a figure of issues. First, authorities support and backup is required to put up a successful showing procedure. Second, raised consciousness and instruction of the general population about hearing loss are needed in order for quicker presentation. Hopefully, this will finally take in the signifier of familial guidance of blood related parents and households with a positive histories of hearing damage.

As bar is better than remedy, it is a timely chance for the OBs and neonatal services in Libya to be reviewed. Perinatal and neonatal causes of hearing loss appear to be prevailing in our survey for some ground or another. Eleven patients ( 29.7 % ) had histories associating to conditions such as birth asphyxia, meconium aspiration, feverish paroxysms and maternal German measles. Future research and reappraisal of the mentioned services in Libya may place and foreground the possible causes of such events during perinatal and neonatal attention and suggest agencies of betterment and prospective development.

Familial causes of hearing damage are an of import cause of terrible and profound hearing loss ( AW Smith 2001 ) . Previous surveies ( Singh AP 1980 ; Elahi et Al. 1998 ) have revealed that 70 % of instances of terrible hearing loss were the consequence of akin matrimonies ( Pakistan paper ) . From our informations, 16 patients ( 43.2 % ) were born to blood related parents. Seventeen patients ( 45.9 % ) of patients had a positive household history of hearing loss. Interesting, as shown in tabular array… .. , eleven of the 17 ( 64.7 % ) had parents blood related to the 1st grade. Although, possibly non common in the West, the pattern of akin matrimonies isA prevalent and frequent pattern in many states across the universe, particularly in the Middle East and parts of Asia for a figure of societal and cultural fortunes ( Pakistan paper, SA paper, Singh AP ; mention akin ) . This makes undertaking the subject of hearing loss that spot harder. In malice of this, certain stairss should be taken in position of forestalling hearing loss every bit much as possible. Schemes such as wellness instruction, familial guidance, equal perinatal and neonatal attention, immunization programmes and testing will all impact the figure of patients that could be potentially give back the gift of hearing.

Decision

The Libyan cochlear implant programme has proved to be a successful rehabilitative intercession for kids and grownups in the state. Schemes such as wellness instruction, familial guidance, equal perinatal and neonatal attention, immunization programmes and testing will all impact the figure of patients that could be potentially give back the gift of hearing.