Search Results

You are looking at 1 - 9 of 9 items for

  • Author or Editor: Mahmoud Kamel x
Clear All Modify Search
Restricted access

Joseph Kelly, Chris Lim, Mahmoud Kamel, Catherine Keohane and Michael O'Sullivan

✓ Despite the fact that gout is a common metabolic disorder, because its involvement of the axial skeleton is rare the diagnosis is often delayed, even in patients with long-standing gout who present with neurological deficits. The authors report the case of a woman with a history of extensive gout, emphasizing the clinical, radiological, and pathological features of a lumbar spinal stenosis.

Full access

Omar A. AlMasri, Emma E. Brown, Alan Forster and Mahmoud H. Kamel

Object

The aim in this paper was to localize and detect incipient damage to the ophthalmic and maxillary branches of the trigeminal nerve during tumor surgery.

Methods

This was an observational study of patients with skull base, retroorbital, or cavernous sinus tumors warranting dissection toward the cavernous sinus at a university hospital. Stimuli were applied as normal during approach to the cavernous sinus to localize cranial nerves (CNs) III, IV, and VI. Recordings were also obtained from the facial muscles to localize CN VII. The trigeminofacial reflex was sought simply by observing a longer time base routinely.

Results

Clear facial electromyography responses were reproduced when stimuli were applied to the region of V1, V2, and V3. Response latency was increased compared with direct CN VII stimuli seen in some cases. Responses gave early warning of approach to these sensory trigeminal branches.

Conclusions

The authors submit this as a new technique, which may improve the chances of preserving trigeminal sensory branches during surgery in this region.

Restricted access

Skull base tumor model

Laboratory investigation

Cristian Gragnaniello, Remi Nader, Tristan van Doormaal, Mahmoud Kamel, Eduard H. J. Voormolen, Giovanni Lasio, Emad Aboud, Luca Regli, Cornelius A. F. Tulleken and Ossama Al-Mefty

Object

Resident duty-hours restrictions have now been instituted in many countries worldwide. Shortened training times and increased public scrutiny of surgical competency have led to a move away from the traditional apprenticeship model of training. The development of educational models for brain anatomy is a fascinating innovation allowing neurosurgeons to train without the need to practice on real patients and it may be a solution to achieve competency within a shortened training period. The authors describe the use of Stratathane resin ST-504 polymer (SRSP), which is inserted at different intracranial locations to closely mimic meningiomas and other pathological entities of the skull base, in a cadaveric model, for use in neurosurgical training.

Methods

Silicone-injected and pressurized cadaveric heads were used for studying the SRSP model. The SRSP presents unique intrinsic metamorphic characteristics: liquid at first, it expands and foams when injected into the desired area of the brain, forming a solid tumorlike structure. The authors injected SRSP via different passages that did not influence routes used for the surgical approach for resection of the simulated lesion. For example, SRSP injection routes included endonasal transsphenoidal or transoral approaches if lesions were to be removed through standard skull base approach, or, alternatively, SRSP was injected via a cranial approach if the removal was planned to be via the transsphenoidal or transoral route. The model was set in place in 3 countries (US, Italy, and The Netherlands), and a pool of 13 physicians from 4 different institutions (all surgeons and surgeons in training) participated in evaluating it and provided feedback.

Results

All 13 evaluating physicians had overall positive impressions of the model. The overall score on 9 components evaluated—including comparison between the tumor model and real tumor cases, perioperative requirements, general impression, and applicability—was 88% (100% being the best possible achievable score where the evaluator strongly agreed with the proposed factor). Individual components had scores at or above 80% (except for 1). The only score that was below 80% was related to radiographic visibility of the model for adequate surgical planning (score of 74%). The highest score was given to usefulness in neurosurgical training (98%).

Conclusions

The skull base tumor model is an effective tool to provide more practice in preoperative planning and technical skills.

Restricted access

Mahmoud Hamdy Kamel, Martin Murphy, Michael Kelleher, Kristian Aquilina, Chris Lim and Charles Marks

✓ The authors report on a case of schistosomiasis of the spinal cord in an individual returning to Ireland after a 25-year residence in Africa, where the infection affects approximately 200 million people.

Restricted access

Kristian Aquilina, Christopher Lim, Mahmoud Hamdy Kamel, Charles J. Marks, Michael G. O'Sullivan and Catherine Keohane

✓ Epithelioid hemangioendothelioma (EH) is a rare tumor of vascular origin. The authors describe two cases of spinal EH, one involving the T-10 vertebra and the second involving the upper cervical spine. In the first case the patient underwent resection of the tumor; this case represents the longest reported follow-up period for spinal EH. In the second case, extensive involvement of C-2, C-3, and C-4 as well as encasement of both vertebral arteries precluded safe tumor resection, and posterior occipitocervical stabilization was performed. The patient subsequently died of metastatic disease. The findings in these two cases underscore the difficulty in predicting the clinical behavior of spinal EH based solely on histological and clinical features as well as the uncertainty of the roles of surgery, chemotherapy, and radiotherapy in the oncological management of a spinal tumor for which clinical data are very limited.

Restricted access

Michael O. Kelleher, Dylan J. Murray, Anne McGillivary, Mahmoud H. Kamel, David Allcutt and Michael J. Earley

Object

The neurobehavioral morbidity of nonsyndromic trigonocephaly is incompletely understood. The purpose of this study was twofold: first, to assess the degree of developmental, educational, and behavioral problems in patients with nonsyndromic trigonocephaly and second, to establish whether patients with mild degrees of trigonocephaly had a lower frequency of such problems.

Methods

The authors performed an observational study of the frequency of developmental, educational, and behavioral problems in 63 children with trigonocephaly at the National Craniofacial Centre in the Republic of Ireland between 1989 and 2004. The parents of the children completed a follow-up questionnaire. Thirty percent of patients had a mild form of trigonocephaly and were treated conservatively. The remainder underwent surgical correction. Speech and/or language delay was reported in 34% of the children. Thirty-three percent of the children needed to be assessed by a school psychologist, and 47% were receiving remedial or resource hours within the school system. Twenty percent of children required a special needs classroom assistant because of behavioral issues, and 37% of parents expressed concerns about their child’s behavior. There were no statistically significant differences between children treated with surgery and those who had a mild deformity and were treated conservatively.

Conclusions

Nonsyndromic trigonocephaly is associated with a high frequency of developmental, educational, and behavioral problems. The frequency of these problems is not related to the severity of the trigonocephaly.

Restricted access

Mahmoud Hamdy Kamel, Chris Lim, Michael Kelleher, Kristian Aquilina, Catherine Keohane and George Kaar

✓ Chordoma is a locally invasive tumor of low metastatic potential. Only six cases of chordoma that metastasized to the brain are found in the English literature. Most of these lesions were clinically silent and all were associated with extraneural metastases. The authors report a case of symptomatic brain metastasis from a sacrococcygeal chordoma in the absence of other metastases. The incidence, sites, and factors predictive of chordoma metastasis are discussed.

Restricted access

Mahmoud Hamdy Kamel, Michael Kelleher, Kristian Aquilina, Chris Lim, John Caird and George Kaar

Object. Neuroendoscopists often note pulsatility or flabbiness of the floor of the third ventricle during endoscopic third ventriculostomy (ETV) and believe that either is a good indication of the procedure's success. Note, however, that this belief has never been objectively measured or proven in a prospective study. The authors report on a simple test—the hydrostatic test—to assess the mobility of the floor of the third ventricle and confirm adequate ventricular flow. They also analyzed the relationship between a mobile floor (a positive hydrostatic test) and prospective success of ETV.

Methods. During a period of 3 years between July 2001 and July 2004, 30 ETVs for obstructive hydrocephalus were performed in 22 male and eight female patients. Once the stoma had been created, the irrigating Ringer lactate solution was set at a 30-cm height from the external auditory meatus, and the irrigation valve was opened while the other ports on the endoscope were closed. The ventricular floor ballooned downward and stabilized. The irrigation valve was then closed and ports of the endoscope were opened. The magnitude of the upward displacement of the floor was then assessed. Funneling of the stoma was deemed to be a good indicator of floor mobility, adequate flow, and a positive hydrostatic test. All endoscopic procedures were recorded using digital video and recordings were subsequently assessed separately by two blinded experienced neuroendoscopists. Patients underwent prospective clinical follow up during a mean period of 11.2 months (range 1 month–3 years), computerized tomography and/or magnetic resonance imaging studies of the brain, and measurements of cerebrospinal fluid pressure through a ventricular reservoir when present. Failure of ETV was defined as the subsequent need for shunt implantation. The overall success rate of the ETV was 70% and varied from 86.9% in patients with a mobile stoma and a positive hydrostatic test to only 14.2% in patients with a poorly mobile floor and a negative test (p < 0.05). The positive predictive value of the hydrostatic test was 86.9%, negative predictive value 85.7%, sensitivity 95.2%, and specificity 66.6%.

Conclusions. The authors concluded that the hydrostatic test is an easy, brief test. A positive test result confirms a mobile ventricular floor and adequate flow through the created ventriculostomy. Mobility of the stoma is an important predictor of ETV success provided that there is no obstruction at the level of the arachnoid granulations or venous outflow. A thin, redundant, mobile third ventricle floor indicates a longstanding pressure differential between the third ventricle and the basal cisterns, which is a crucial factor for ETV success. A positive hydrostatic test may avert the need to insert a ventricular reservoir, thus avoiding associated risks of infection.

Full access

Mahmoud Hamdy Kamel, Michael Kelleher, Kristian Aquilina, Chris Lim, John Caird and George Kaar

Object

Neuroendoscopists often note pulsatility or flabbiness of the floor of the third ventricle during endoscopic third ventriculostomy (ETV) and believe that either is a good indication of the procedure's success. Note, however, that this belief has never been objectively measured or proven in a prospective study. The authors report on a simple test—the hydrostatic test—to assess the mobility of the floor of the third ventricle and confirm adequate ventricular flow. They also analyzed the relationship between a mobile floor (a positive hydrostatic test) and prospective success of ETV.

Methods

During a period of 3 years between July 2001 and July 2004, 30 ETVs for obstructive hydrocephalus were performed in 22 male and eight female patients. Once the stoma had been created, the irrigating Ringer lactate solution was set at a 30-cm height from the external auditory meatus, and the irrigation valve was opened while the other ports on the endoscope were closed. The ventricular floor ballooned downward and stabilized. The irrigation valve was then closed and ports of the endoscope were opened. The magnitude of the upward displacement of the floor was then assessed. Funneling of the stoma was deemed to be a good indicator of floor mobility, adequate flow, and a positive hydrostatic test. All endoscopic procedures were recorded using digital video and recordings were subsequently assessed separately by two blinded experienced neuroendoscopists. Patients underwent prospective clinical follow up during a mean period of 11.2 months (range 1 month–3 years), computerized tomography and/or magnetic resonance imaging studies of the brain, and measurements of cerebrospinal fluid pressure through a ventricular reservoir when present. Failure of ETV was defined as the subsequent need for shunt implantation. The overall success rate of the ETV was 70% and varied from 86.9% in patients with a mobile stoma and a positive hydrostatic test to only 14.2% in patients with a poorly mobile floor and a negative test (p < 0.05). The positive predictive value of the hydrostatic test was 86.9%, negative predictive value 85.7%, sensitivity 95.2%, and specificity 66.6%.

Conclusions

The authors concluded that the hydrostatic test is an easy, brief test. A positive test result confirms a mobile ventricular floor and adequate flow through the created ventriculostomy. Mobility of the stoma is an important predictor of ETV success provided that there is no obstruction at the level of the arachnoid granulations or venous outflow. A thin, redundant, mobile third ventricle floor indicates a longstanding pressure differential between the third ventricle and the basal cisterns, which is a crucial factor for ETV success. A positive hydrostatic test may avert the need to insert a ventricular reservoir, thus avoiding associated risks of infection.