Simon K W Lloyd

Cambridge University Hospitals NHS Foundation Trust, Cambridge, England, United Kingdom

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Publications (12)10 Total impact

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    ABSTRACT: To date, only a very limited number of lipomas of the cerebellopontine angle (CPA) have been reported. Our objective was to examine clinical and radiologic features of CPA lipomas and determine the most appropriate management plan. Retrospective case series. Tertiary referral center. Patients with CPA lipomas were identified through the skull base multidisciplinary meeting database. Radiologic surveillance and clinical assessment. Tumor growth, assessed through radiologic measurements on serial magnetic resonance imaging, demographics, presenting symptoms, and any correlation between weight gain and lipoma growth were among the examined factors. Of the 15 patients with CPA lipomas, six were female and nine were male, with an average age at presentation of 50.2 years (range, 31.7-76.4 yr) and an average follow-up time of 51.7 months (range, 6-216 mo). The lipomas were unilateral in all cases, nine on the right (60%) and six on the left (40%) side. None of the lipomas increased in size. All patients were treated conservatively. Sensorineural hearing loss was the main presenting symptom (80%) followed by tinnitus (46.7%) and vertigo (20%). None of the patients suffered from facial nerve dysfunction. There was no correlation between weight gain and tumor growth. CPA lipomas can be diagnosed accurately with appropriate magnetic resonance imaging techniques and be managed conservatively with safety. Cochleovestibular are the most common presenting symptoms, whereas facial nerve involvement is rare. CPA lipomas do not tend to grow and can be monitored on a less regular basis.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 03/2014; · 1.44 Impact Factor
  • Simon Lloyd, Deborah Mawman, Chris Raine
    Cochlear implants international 11/2013; 14 Suppl 4:1-2.
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    ABSTRACT: The assessment process is critical in deciding whether a profoundly deaf child with cochlear nerve deficiency (CND) will be suitable for a cochlear or auditory brainstem implant (ABI). Magnetic resonance imaging (MRI) using submillimetric T2 weighted gradient echo or turbo spin echo sequences is mandatory for all profoundly deaf children to diagnose CND. Evidence of audition on behavioural or electrophysiological tests following both auditory and electrical stimulation sometimes allows identification of significant auditory tissue not visible on MRI. In particular electric auditory brainstem response (EABR) testing may allow some quantification of auditory tissue and help decide whether a cochlear implant will be beneficial. Age and cognitive development are the most critical factors in determining ABI benefit. Hearing outcomes from both cochlear implants and ABIs are variable and likely to be limited in children with CND. A proportion of children will get no benefit. Usually the implants would be expected to provide recognition of environmental sounds and understanding of simple phonetics. Most children will not develop normal speech and they will often need to learn to communicate with sign language. The ABI involves a major neurosurgical procedure and at present the long term outcomes are unknown. It is therefore essential that parents who are considering this intervention have plenty of time to consider all aspects and the opportunity for in depth discussion.
    Cochlear implants international 11/2013; 14 Suppl 4:27-31.
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    ABSTRACT: Hearing loss resulting from bilateral vestibular schwannomas (VSs) has a significant effect on the quality of life of patients with neurofibromatosis Type 2 (NF2). A national consensus protocol was produced in England as a guide for cochlear implantation (CI) and auditory brainstem implantation (ABI) in these patients. Consensus statement. English NF2 Service. Clinicians from all 4 lead NF2 units in England. A protocol for the assessment, insertion and rehabilitation of CI and ABI in NF2 patients RESULTS: Patients should undergo more detailed hearing assessment once their maximum aided speech discrimination score falls below 50% in the better hearing ear. Bamford-Kowal-Bench sentence testing scores below 50% should trigger assessment for auditory implantation, as recommended by the National Institute for Clinical Excellence guidelines on CI. Where this occurs in patients with bilateral stable VS or a unilateral stable VS where the contralateral cochlear nerve was lost at previous surgery, CI should be considered. Where VS surgery is planned, CI should be considered where cochlear nerve preservation is thought possible, otherwise an ABI should be considered. Intraoperative testing using electrically evoked auditory brainstem responses or cochlear nerve action potentials may be used to determine whether a CI or ABI is inserted. The NF2 centers in England agreed on this protocol. Multisite, prospective assessments of standardized protocols for auditory implantation in NF2 provide an essential model for evaluating candidacy and outcomes in this challenging patient population.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 10/2013; · 1.44 Impact Factor
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    ABSTRACT: Objectives. To analyse the long-term outcome of translabyrinthine surgery for vestibular schwannoma (VS) in neurofibromatosis type 2 (NF2). Research type. Retrospective cohort study. Setting. Two tertiary referral NF2 units. Patients. One hundred and forty eight translabyrinthine operations for patients with VS were performed. Preoperative stereotactic radiotherapy had been performed on 12(9.4%) patients. Results. Mean tumour size was 3.1 cm. Total tumour excision was achieved in 66% of cases, capsular remnants were left in 24% of cases, and subtotal excision was achieved in 5% and partial removal was achieved in 5%. The radiological residual/recurrence rate was 13.9%. The perioperative mortality was 1.6%. At 2 years postoperatively, facial function was expressed in terms of House-Brackmann score (HB): HB 1 in 53.4%, HB 1/2 in 61.3%, HB 1-3 in 83.2% and HB 4-6 in 16.8%. All nine patients who underwent surgery following failed stereotactic radiotherapy had HB 3 function or better. Among 9.5% of the cases, 14 facial nerves were lost during surgery and repaired using direct anastomosis or grafting. There was no tinnitus present preoperatively in 27% of the cases, and 22% of patients developed tinnitus postoperatively. In patients with preoperative tinnitus, 61% remained the same, 17% got it resolved and only in 21% it worsened. The preoperative hydrocephalus rate was 26%, and among 15% of the cases five ventriculo-peritoneal (VP) shunts were performed. The cerebrospinal fluid leak rate was 2.5%. Fifty-six patients underwent auditory brainstem implantation (ABI) and two patients had cochlear implant (CI) sleepers inserted. Conclusions. The management of patients with NF2 presents the clinician with a formidable challenge with many patients still presenting themselves late with the neurological compromise and a large tumour load. There is still an argument for the management by observation until the neurological compromise dictates interventional treatment particularly with the option of hearing rehabilitation with ABI or CI. The translabyrinthine approach provides a very satisfactory means of reducing the overall tumour volume.
    British Journal of Neurosurgery 03/2013; · 0.86 Impact Factor
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    ABSTRACT: There is very little information in the literature regarding outcomes of cochlear implantation in patients profoundly deafened after head injury. The aim of this study was to assess outcomes in this group of patients. Retrospective case review. The Manchester Cochlear Implant Programme, University of Manchester. Profoundly deafened patients after head injury who proceeded to cochlear implantation for auditory rehabilitation. Mean age and duration of deafness at implantation. Preimplantation and postimplantation speech perception outcomes were measured using Bench Kowel Bamford (BKB) sentences in quiet and noise, City University of New York sentences with lip reading and Arthur Boothroyd words scoring the percentage phonemes correct. Twenty patients received 23 cochlear implants. Mean age at implantation was 51 years (standard deviation, 12 yr). Mean duration of deafness at implantation was 12 years (range, 1-30 yr).Preimplantation BKB score in quiet of 0%. Mean postimplantation BKB score in quiet was 64% (range, 0%-100%) and in noise was 61% (range, 0%-97%). Three were nonusers, and 1 required reimplantation. There was a moderately negative correlation between outcome and age at implantation (r = -0.41, p < 0.05) and between outcome and duration of deafness (r = -0.52, p < 0.05). Cochlear implantation is an effective method for hearing rehabilitation in profoundly deafened patients after head injury. However, negative factors, such as significant injury to the central auditory pathway, basal turn obliteration, long duration of deafness, and nonauditory stimulation, should be considered in the preoperative assessment of these patients.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 08/2012; 33(8):1328-32. · 1.44 Impact Factor
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    ABSTRACT: A new dual temporal resolution-based, high spatial resolution, pharmacokinetic parametric mapping method is described--improved coverage and spatial resolution using dual injection dynamic contrast-enhanced (ICE-DICE) MRI. In a dual-bolus dynamic contrast-enhanced-MRI acquisition protocol, a high temporal resolution prebolus is followed by a high spatial resolution main bolus to allow high spatial resolution parametric mapping for cerebral tumors. The measured plasma concentration curves from the dual-bolus data were used to reconstruct a high temporal resolution arterial input function. The new method reduces errors resulting from uncertainty in the temporal alignment of the arterial input function, tissue response function, and sampling grid. The technique provides high spatial resolution 3D pharmacokinetic maps (voxel size 1.0 × 1.0 × 2.0 mm(3)) with whole brain coverage and greater parameter accuracy than that was possible with the conventional single temporal resolution methods. High spatial resolution imaging of brain lesions is highly desirable for small lesions and to support investigation of heterogeneity within pathological tissue and peripheral invasion at the interface between diseased and normal brain. The new method has the potential to be used to improve dynamic contrast-enhanced-MRI techniques in general.
    Magnetic Resonance in Medicine 08/2012; 68(2):452-62. · 3.27 Impact Factor
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    ABSTRACT: To assess the growth characteristics of small- to medium-sized vestibular schwannomas in patients undergoing watch, wait, and rescan management. Cohort study using prospectively collected size and tumor morphology data. Tertiary referral center for cranial base surgery. Three hundred eighty-one patients with sporadic unilateral vestibular schwannomas and 2 or more magnetic resonance scans were included. Linear measurements were used to assess tumor size. The point of growth and pattern of growth progression were assessed. Factors influencing growth were investigated. Approximately 33% of tumors demonstrated significant growth. Mean size at presentation was 9.9 mm (standard deviation [SD]. 4.8). For growing tumors, mean size at final review was 13.7 mm (SD, 4.8). This was a statistically significant increase in size (p < 0.0001). Mean annual change in size for growing tumors was 2.3 mm (SD, 2.3). 52.4% of growing tumors showed radiologically demonstrable first growth within 18 months of presentation. Approximately 7.2% of tumors showed radiologically demonstrable first growth after 5 years of follow-up. There were no demographic or morphologic predictors of growth. Tumor growth is usually slow and is most likely to occur within the first 3 years of observation. Growth may occur after five years of follow-up. A protocol for the scanning of patients is suggested based on the findings of the study.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 06/2012; 33(6):1053-8. · 1.44 Impact Factor
  • Gareth R Evans, Simon K W Lloyd, Richard T Ramsden
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    ABSTRACT: Neurofibromatosis type 2 (NF2) is an autosomal-dominant inherited tumour predisposition syndrome caused by mutations in the NF2 gene on chromosome 22. Affected individuals develop schwannomas characteristically affecting both vestibular nerves leading to hearing loss and eventual deafness. Rehabilitation with brain stem implants and in some cases cochlear implants is improving this outcome. Schwannomas also occur on other cranial nerves, on spinal nerve roots and peripheral nerves. Meningiomas and ependymomas are other tumour features. In excess of 50% of patients represent de novo mutations and as many as 33% are mosaic for the underlying disease causing mutation. Truncating mutations (nonsense, frameshift insertions/deletions) are the most frequent germline events and cause the most severe disease, whilst single and multiple exon deletions are common and are usually associated with milder NF2. A strategy for detection of the latter is vital for a sensitive genetic analysis. NF2 represents a difficult management problem with most patients facing substantial morbidity and reduced life expectancy. Surgery remains the focus of current management although watchful waiting and occasionally radiation treatment have a role. We are seeing the advent of tailored drug therapies aimed at the genetic level and these are likely to provide huge improvements for this devastating, life limiting condition.
    Advances in oto-rhino-laryngology 01/2011; 70:91-8.
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    ABSTRACT: Meningiomas have been reported to occur in approximately 50% of neurofibromatosis type 2 (NF2) patients. The NF2 gene is commonly biallelically inactivated in both schwannomas and meningiomas. The spectrum of NF2 mutations consists mainly of truncating (nonsense and frameshift) mutations. A smaller number of patients have missense mutations, which are associated with a milder disease phenotype. This study analysed the cumulative incidence and gender effects as well as the genotype-phenotype correlation between the position of the NF2 mutation and the occurrence of cranial meningiomas in a cohort of 411 NF2 patients with proven NF2 mutations. Patients with mutations in exon 14 or 15 were least likely to develop meningiomas. Cumulative risk of cranial meningioma to age 50 years was 70% for exons 1-3, 81% for exons 4-6, 49% for exons 7-9, 56% for exons 10-13, and 28% for exons 14-15. In the cohort of 411 patients, no overall gender bias was found for occurrence of meningioma in NF2 disease. Cumulative incidence of meningioma was close to 80% by 70 years of age for both males and females, but incidence by age 20 years was slightly increased in males (male 25%, female 18%; p=0.023). Conversely, an increased risk of meningiomas in women with mosaic NF2 disease was also found.
    Journal of Medical Genetics 01/2011; 48(4):261-5. · 5.70 Impact Factor
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    ABSTRACT: To measure the health-related quality of life (QoL) of patients undergoing conservative management of a vestibular schwannoma and to identify audiovestibular factors that influence health-related QoL. Cross-sectional case-control study. Adult patients undergoing conservative management of a sporadic vestibular schwannoma were identified from a prospectively updated database. Each patient was asked to complete a series of questionnaires, including the Short Form 36 health-related QoL instrument, the Hearing Handicap Inventory, the Tinnitus Handicap Inventory, and the Dizziness Handicap Inventory. The QoL data obtained were compared with UK normal data. Multiple linear regression was performed to identify audiovestibular factors influencing QoL. Of 241 patients still undergoing conservative management, 165 completed the questionnaires. The mean age was 66.6 years. Mean duration of follow-up was 5.7 years. Physical component summary scores were significantly lower than those of the normal population. Mental component summary scores were significantly above the normal population. Regression analysis showed that dizziness handicap score and age were strong predictors of physical component summary (both p < 0.0001). Dizziness handicap score and tinnitus handicap score were significant predictors of mental component summary (p = 0.0004 and p = 0.027 respectively). However, the model only explained a small amount of the data, suggesting that there may be other factors influencing QoL. Dizziness is the most significant audiovestibular predictor of QoL in patients with vestibular schwannomas. Tinnitus also has an impact on mental QoL. Hearing loss does not seem to influence QoL. Other factors such as illness perception may have an important role to play in determining QoL.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 08/2010; 31(6):968-76. · 1.44 Impact Factor
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    ABSTRACT: To investigate changes in cochlear orientation with age and discuss the implications of any change with respect to cochlear implantation. Cross-sectional study of computed tomographic scans of the temporal bones in patients with no congenital abnormalities. One hundred fifty-nine patients were included in the study, making a total of 318 ears. The age range was 9 months to 85 years. Axial computed tomographic scans showing the basal turn of the cochlea were identified. The angle of the basal turn of the cochlea was measured by drawing a line through the long axis of the basal turn and measuring its angle with a line drawn through the midsagittal plane. The patients were grouped according to age, and a 1-way analysis of variance was used to identify any statistically significant change in basal turn angulation. Interobserver and intraobserver errors were calculated and presented as repeatability coefficients. The basal turn angles of 3 difficult cases of cochlear implantation were related to the findings. The mean basal turn angle was 54.6 degrees (range, 46.8-63.8 degrees; standard deviation, 3.5). There was a statistically significant reduction in the angulation of the basal turn with increasing age (F = 10.1; p = 0.002). The majority of the change occurs between the ages of 11 and 15 years. The interobserver reliability coefficient was 4.8. The intraobserver reliability coefficient was 2.0. The 3 difficult cases had basal turn angles that were at the upper limit of the reference range. There is a statistically significant reduction in basal turn angulation relative to the midsagittal plane with increasing age. However, care should be taken in interpreting these results in light of the inherent error in the measuring technique, although the intraobserver repeatability coefficient was only 2.0. The more obtuse angulation of the basal turn in children may have implications for cochlear implantation.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 08/2010; 31(6):902-7. · 1.44 Impact Factor
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    ABSTRACT: Herpes simplex is a common human pathogen that has rare but severe manifestations including encephalitis. A 44-year-old man underwent uneventful resection of an acoustic neuroma. Postoperatively, he developed swinging pyrexia, vomiting, and episodic confusion. Analysis of cerebrospinal fluid showed a lymphocytosis, and polymerase chain reaction revealed herpes simplex DNA. After treatment of herpes encephalitis with acyclovir, the patient made a good recovery. Herpes encephalitis is a rare complication of neurosurgical procedures, and the most likely etiology is reactivation of latent infection from manipulation of cranial nerves.
    Surgical Neurology 08/2009; 72(5):502-4. · 1.67 Impact Factor
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    ABSTRACT: To determine the prevalence of Bruns' nystagmus in patients undergoing surgical treatment for unilateral sporadic vestibular schwannomas (VSs), identify the clinical characteristics of patients with Bruns' nystagmus and compare these characteristics with those of VS patients with no nystagmus and other types of nystagmus, and determine the long-term impact of having preoperative Bruns' nystagmus. A retrospective review using a prospectively updated database of patients who had undergone surgical removal of a VS. Patients were divided into 3 groups: Bruns' nystagmus, other types of nystagmus, or no nystagmus. Statistical comparison of each group was undertaken. Nine hundred eighty-four patients were included consisting of 492 men and 492 women with a mean age of 59 years (range, 11-86 yr). Bruns' nystagmus was present in 11% of patients. Bruns' nystagmus was associated with larger tumor size (p < 0.001). Beyond 3.5-cm maximum diameter, 92% of patients had nystagmus, 67% of which had Bruns' nystagmus. Preoperative balance impairment was present in 95% of patients with Bruns' nystagmus compared with 59% with no nystagmus. The balance status of all groups improved considerably postoperatively, but the patients with Bruns' nystagmus had a relatively greater improvement in balance status. Bruns' nystagmus occurs in patients with large VSs. These patients tend to have greater balance impairment pre\operatively, but after surgery, long-term balance outcomes are similar to those of patients with no nystagmus or other forms of nystagmus.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 06/2009; 30(5):625-8. · 1.44 Impact Factor
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    ABSTRACT: Vestibular schwannomas are benign, slow-growing tumors that originate from Schwann cells lining the vestibular nerves, most commonly the superior vestibular nerve. They arise at the neurilemmal/neuroglial junction which is situated within the internal auditory canal. They have an incidence of 1 per 100,000 per year and a prevalence of around 700 per million. A case of a patient undergoing a period of observation for a vestibular schwannoma whose hearing improved despite growth of the tumor is described. This raises interesting questions regarding the pathophysiology of hearing loss in patients with vestibular schwannomas. Possible hypotheses are discussed.
    Skull Base Surgery 04/2009; 19(2):159-62. · 0.72 Impact Factor
  • Otolaryngology-head and Neck Surgery - OTOLARYNGOL HEAD NECK SURG. 01/2009; 141(3).
  • Otolaryngology-head and Neck Surgery - OTOLARYNGOL HEAD NECK SURG. 01/2009; 141(3).
  • Otolaryngology-head and Neck Surgery - OTOLARYNGOL HEAD NECK SURG. 01/2009; 141(3).
  • S K W Lloyd, D M Baguley
    Clinical otolaryngology: official journal of ENT-UK; official journal of Netherlands Society for Oto-Rhino-Laryngology & Cervico-Facial Surgery 03/2008; 33(1):25-8. · 1.87 Impact Factor
  • Skull Base-an Interdisciplinary Approach - SKULL BASE-AN INTERDISCIP APP. 01/2008; 18.