Text Box: Vertigo resulting from pathological neck conditions like cervical trauma, spondylosis and traction is postulated to arise from three mechanisms vis (1) arthritic involvement of sympathetic plexuses around the vertebral arteries, (2) osteophytic compression of vertebral arteries and (3) altered tonic neck reflexes (Grewal et al, Ind. J. Otology, 1997 Dec.; 3(4): 168-72). Diagnosis often entails the clinician rules out other causes of post-traumatic vertigo, and the gold standard for positive confirmation is vertebral angiography, an often risky procedure. A recent study from Greece (Olszewski et al, Otolaryngol Head Neck Surg. 2006 Apr;134(4):680-4.) investigated the association in patients with cervical spondylosis of positional blood flow in vertebral and basilar arteries and observed significant association. Abstract: OBJECTIVE: The aim of our investigations was to characterize the relationship between basilar artery (BA) flow velocity in patients with cervical spondylosis and age, grade of radiological changes, prevalence of vertigo, and decreased blood flow velocity through vertebral arteries (VA) after head rotation. STUDY DESIGN AND SETTING: A prospective, controlled study in academic neurotology was conducted. We examined 80 patients with radiological evidence of cervical spondylosis. Forty patients complained of positional vertigo lasting more than 6 months. Patients were examined by transcranial Doppler ultrasound with head rotations. RESULTS: We showed significant association between velocity flow in basilar artery after neck rotation and age, prevalence of vertigo, grade of radiological changes, and positional vertebral artery flow lesion. CONCLUSION: Spondylotic-induced VA compression may be the reason for decreased blood flow velocity in the basilar artery during head rotation, which may be of particular importance for older patients, especially complaining of vertigo. SIGNIFICANCE: Every patient with high-grade cervical spondylosis, especially complaining of vertigo, should be examined by using TCD (transcranial Doppler) with head rotations. In case of positional blood flow reduction during head rotation, further angiographic examination should be undertaken so as to plan suitable treatment. Text Box: Editor's Choice: Cervical Vertigo & Transcranial Doppler...? Text Box: The issue of how to predict outcome in cases with severe acute head injury has been at the front burner of most ICU clinicians worries. Most of the models suggested have been mathematical , relying on formulas involving Glasgow coma scale, brain stem reflexes, best motor response, etc, with that of  Mukherjee KK at al (Neurol India 2000;48:43-8) been the most curious. A recent study from Australia (Wilson et al, Audiology and Neurotology 2006;11:249-258) reported that in patients with acute severe closed head injury, the addition of time-frequency information can improve the ability of the 'normal' ABR result to predict outcome. Abstract:  Previous research has shown that complex statistical analysis (discriminant function analysis) of a 'normal' auditory brainstem response (ABR) result can improve this measure's ability to predict subject outcome following severe acute closed head injury (ACHI). We hypothesized that adding the ABR's time-frequency information to such an analysis would improve this predictive value even further. 'Normal' ABR results were sampled from 69 severe ACHI subjects (22 of whom died and 47 of whom lived) and their time-frequency information extracted using an over-complete discrete wavelet transformation (OCDWT). A series of logistic regression analyses then showed correct predictions of death and survival as follows: ABR measures only 72 and 89% (respectively), ABR OCDWT measures only 82 and 89% (respectively), and ABR and ABR OCDWT measures combined 86 and 93% (respectively). These results showed that the addition of time-frequency information can improve the ability of the 'normal' ABR result to predict outcome following severe ACHI. Text Box: Abreast of Ear, Nose, Throat, Head & Neck Advances

Text Box: Volume 3, N0. 6 Text Box: May 14, 2006

Text Box: Otorhinolaryngology News

Text Box: Inside This Issue · Cervical Vertigo & TC Doppler · ABR & Outcome of ACHI · More on OAE & NHSP *     Case of the Week

 

 

 Case Review

 Clinical Photo of The Week
A 48-year old male presented with a year history of diminished hearing on the left. He gave a history of left ear canal surgery 10 years earlier. The surgery was to correct post traumatic closure of left ear canal observed following a vehicular accident. Examination revealed the sign shown in this picture. CT-Scan showed normal distal 1/3rd bony canal, normal middle and inner ear, and soft tissue density in the outer 2/3rd ear canal. Audiometry revealed air-bone gap of 15-20dB across speech frequencies.

What is the Diagnosis?
Text Box: Coming Events of Importance to Otorhinolaryngologists in Africa

1.          8th International Otology Course of the Jean Causse Ear Clinic June 22-24, 2006; Béziers, France

2. 110th American Academy of ORL, Head & Neck Surgery Annual Meeting & OTO EXPO, September 17-20, 2006; Toronto, Canada.

3. 42nd South African ENT Congress joint meeting with the British Association of Otolaryngology - Head & Neck Surgery, October 29-November 1, 2006; Cape Town, South Africa.

Recall the previous editions (Vol1, No5 & Vol3, No5) of this newsletter dealing with the subject of newborn hearing screening program and OAE. This new study from Hong Kong (McPherson B. et al, Ear Hear. 2006 Jun;27(3):256-262) reported that a combination of click-evoked OAE and tone burst-evoked OAE may reduce the incidence of false positive rates observed with OAE in neonatal hearing screening programs

Abstract: OBJECTIVE:: Click-evoked otoacoustic emissions (CEOAEs) are widely used in universal neonatal hearing screening programs. A common finding in many such programs is a relatively high false-positive rate. This is often due to infant physiological noise adversely affecting the emission recording,leading to a "refer" screening outcome. In an attempt to reduce false-positive screening outcomes related to the effects of noise on otoacoustic emission response detection, tone-burst-evoked otoacoustic emissions (TBOAEs) were included in a neonatal hearing screening program because TBOAEs may elicit a greater signal-to-noise ratio than CEOAEs. The research project compared the pass/refer rate for a CEOAE-based test using established pass/refer criteria with the pass/refer rate for screening criteria that were based on TBOAE results alone or on combined CEOAE and TEOAE results. DESIGN:: Neonates were recruited at the Hong Kong Adventist Hospital, and both CEOAEs and TBOAEs were performed. Six passing criteria were used in this study, based on CEOAEs only; CEOAEs plus 1 kHz TBOAEs; CEOAEs plus 2 kHz TBOAEs; CEOAEs plus 3 kHz TBOAEs; CEOAEs plus 1, 2, and 3 kHz TBOAEs; and TBOAEs only. RESULTS:: Data from 298 neonates (546 ears) were obtained. Criteria set 1, using CEOAEs only, demonstrated a pass rate of 79.1%, and 114 ears were referred. Criteria set 2, using CEOAEs together with TBOAEs recorded at 1 kHz, passed 39 more ears than Protocol 1, and the pass rate was 86.3%. Hence, the overall referral rate for total number of screened ears decreased by 7.2 percentage points. Criteria set 3, using CEOAEs together with TBOAEs recorded at 2 kHz, and Criteria set 4, using CEOAEs in conjunction with TBOAEs recorded at 3 kHz, gave pass rates similar to Criteria set 1. Criteria set 5, using TBOAE information at frequencies where CEOAEs were not rated as "pass," raised the pass rate from 79.1 to 87.6%, reducing the overall referral rate by 8.5 percentage points. Criteria set 6, in which neonates were screened with TBOAEs recorded at 1, 2, and 3 kHz, gave a pass rate of 78.4%, similar to results for the CEOAE-only procedure. CONCLUSIONS:: Both Criteria sets 2 and 5, which combined CEOAE and TBOAE recordings, gave significantly higher pass rates than Criteria sets 1, 3, 4, and 6. The results suggest that the introduction of combined CEOAE and TBOAE protocols may assist in the reduction of refer outcomes, and hence the false-positive rates, of neonatal hearing screening programs.
 

                 Journal Watch : Connexin 26 mutations & SNHL in Ghana. Hamelmann et al, 2001

  1.  Reviewers wanted for otolaryngology news journal's watch page. If you are an Otolaryngologist in Africa and will like to be our journal reviewer, please feel free to email orl-mailer@otolaryngologyinafrica.net

  2.   DODA 2006, capable of advanced hearing measure, and also paediatric hearing assessment is being developed. If you requested for and got a free copy of DODA, you may also look out for this latest version dubbed DODA-i, as well as for an additional page on outcome of hearing assessment using DODA.

 3.  You may want to check out this new site dedicated to early detection of hearing loss in developing countries

 Till Next Week,

 Biodun

 

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