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Phillip Chang

Publications and source records attributed to Phillip Chang.

8 recordsLinked to original sources
PubMed2003

Audiologic presentation of cerebellopontine angle cholesteatoma.

OBJECTIVE: The aim of this study was to examine the audiologic presentation of patients with cerebellopontine angle (CPA) cholesteatoma. DESIGN: Retrospective case review. SETTING: Neuro-otologic tertiary referral centre. METHODS: The study population consisted of 11 patients with CPA cholesteatomas. The patients underwent a standard audiologic investigation in the preoperative setting, which consisted of pure-tone audiometry, speech audiometry, and auditory brainstem response (ABR). MAIN OUTCOME MEASURES: The audiologic parameters that were analyzed were the pure-tone threshold, pure-tone average (PTA), and speech discrimination scores (SDSs). The morphology and latency of the ABR were evaluated. In addition, the clinical and radiologic presentations of the lesions were reviewed. RESULTS: The mean PTA in the diseased ear was 22.6 dB HL (SD 18.2), whereas in the contralateral ear, it was 19.1 dB HL (SD 19.6). In 4 patients, the hearing loss was asymmetric, with the diseased ear being the worse ear. The mean SDS was 82.28% in the affected ear and 95.28% in the contralateral ear. ABR was abnormal in 9 of 10 cases (90%), with only the affected ear being abnormal in 4 cases. In the other 5 cases, the ABR was bilaterally abnormal. CONCLUSIONS: CPA cholesteatomas are very slow-growing lesions that involve the eighth cranial nerve. The paucity and insidious onset of symptoms mean that the diagnosis is often late, permitting the lesions to reach impressive dimensions at the time of diagnosis. Although magnetic resonance imaging represents the gold standard in the diagnosis of these lesions, ABR proved to be of value in the assessment of the auditory pathway, especially in those patients referred with a vague symptomatology and with normal hearing.

Adult↗
PubMed2002

Management strategies in neurofibromatosis type 2.

The objective of this study was to review the experience of the Neurotology and Skull Base Surgery Unit of Addenbrooke's Hospital in Cambridge, England, in the management of patients with neurofibromatosis type 2 (NF2). This was a retrospective review of the institution's series conducted at a neurotological tertiary referral centre. Over a 17-year period (1984-2001), 35 patients with NF2 were managed. These patients presented with multiple cranio-spinal neoplasms, including 62 cerebellopontine angle tumours of which 59 were vestibular schwannomas (nine patients with unilateral tumours and 25 patients with bilateral tumours). Clinical presentation, diagnosis and patient management were reviewed. The outcome parameters measured were tumour progression, the incidence of complications (hearing deterioration and facial nerve palsy) and the need for secondary intervention. Five vestibular schwannomas were treated with stereotactic radiosurgery (gamma-knife), all of which showed evidence of progression in size and/or deterioration in hearing. Thirty-one VS were conservatively treated with annual surveillance. In nine cases, the tumours had a follow-up shorter than 6 months and were therefore excluded from the results. In 13 cases the VS did not progress in size, and the hearing remained stable, while in the remaining nine cases, tumour progression was evident. In fifteen cases, surgery was performed at the authors' institution. In 11 cases a translabyrinthine approach was adopted, and in the remaining four cases a retrosigmoid approach was preferred. In all these cases, tumour removal was total and facial nerve function was House-Brackmann grade I-III in 55%. Successful hearing preservation was elusive in those patients in whom a hearing preservation approach was attempted. NF2 remains an extremely challenging disorder for the neurotologist and the patient alike. Early diagnosis offers distinct advantages to the patients, their families and the community at large. Of the treatment modalities, surgery unequivocally offers the most superior tumour control. Hearing preservation remains a challenge in these patients, but is optimised by the early detection of tumours in the NF2 patient.

Adolescent↗
PubMed2002

Staging and management of primary cerebellopontine cholesteatoma.

Primary cerebellopontine angle (CPA) cholesteatoma grows slowly and silently in the subarachnoidal spaces. The diagnosis is often late, when the lesion has reached large dimensions. Surgical removal is the only available therapy. Fifteen consecutive cases of CPA cholesteatoma managed at a tertiary otoneurosurgical referral unit between September 1985 and April 1999 were reviewed. The study population, consisting of seven males and eight females, had a mean age of 44 years of age (range 21-69) at the time of surgery. The clinical, audiological and radiological presentations were examined. The tumours were classified according to the Moffat classification of CPA cholesteatomas. In 67 per cent of cases the presenting symptom was related to the vestibulo-cochlear nerve. The average duration of symptoms was 23 months (ranging from one month-10 years). The hearing preservation approaches were utilized the most (11 cases), while the translabyrinthine approach alone, or in association with a middle fossa craniotomy, was performed in four cases. Tumour removal was total in 12 cases and subtotal in three cases. In cases undergoing hearing preservation surgery the mean pre-operative pure tone average (PTA) for the frequencies 0.5, 1, 2, and 3 kHz was 19.3 dB HL (SD 13.84) and the mean pre-operative speech discrimination score (SDS) was 89.8 per cent (SD 5.97). In 44.4 per cent of patients the hearing was preserved and the mean post-operative PTA was 20.29 dB HL (SD 15.84). In five patients post-operative complications occurred. No peri- or post-operative death occurred in this series, one patient developed a recurrence 15 years after the initial surgery.

Adult↗
PubMed2002

Unusual MRI appearance of an intracranial cholesteatoma extension: the 'billiard pocket sign'.

We describe a unique case of an intracranial extension of acquired cholesteatoma. Previous reports have described cholesteatoma extension through the middle fossa plate and into the middle cranial fossa, but to our knowledge ours is the first report of a case in which the sac herniated into the temporal lobe and overlying dura from a site far lateral to the otic capsule. The findings on magnetic resonance imaging were most unusual, and we call the radiologic characteristics of the mass in this case the "billiard pocket sign." We also discuss the possible mechanisms that produced such an image.

Brain Diseases↗