Ahmed Alkhani

King Faisal Specialist Hospital and Research Centre, Jeddah, Mintaqat Makkah, Saudi Arabia

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Publications (11)15.32 Total impact

  • Ahmed Alkhani
    The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 04/2008; 35(1):91-3. · 1.33 Impact Factor
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    ABSTRACT: To evaluate the diagnostic yield, accuracy, and safety of frame-based stereotactic brain biopsy procedures. A retrospective study of all pathologically diagnosed intracranial lesions, using frame-based stereotactic guided brain biopsy procedures performed at King Faisal Specialist Hospital and Research Centre (KFSH&RC), Riyadh, Kingdom of Saudi Arabia between 1993 and 2005 was conducted. Medical charts, radiological studies, and pathological slides were reviewed. A total of 120 consecutive patients who had frame-based stereotactic diagnostic biopsy procedures were identified. Data regarding procedural techniques, lesion locations, pathological diagnosis, and postoperative complications were collected. Patients` ages ranged from 3-72 years (mean +/- standard deviation: 39.4 +/- 20.3), 67 males and 53 females. Sites of biopsied lesions included: 49 thalamic, 29 deep frontal, 23 parietal, 9 temporal, and 10 others. Targeting accuracy was 99.2%. General anesthesia was used in 103 patients (85.8%). The rest was carried out under local anesthesia. Diagnostic yield was estimated at 96%. Most frequently encountered pathological diagnosis includes gliomas (63%), infections (16%), and lymphomas (7%). One mortality (0.8%), and 5 (4%) morbidities were encountered. Stereotactic brain biopsy is a relatively safe technique to obtain a tissue biopsy that represents the pathology of the lesion. Recent advances in stereotactic neurosurgical techniques have helped to improve the safety and diagnostic yield of such procedures.
    Neurosciences 04/2008; 13(2):142-5. · 0.32 Impact Factor
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    ABSTRACT: Although meningiomas represent the most common class of tumors of the central nervous system, the molecular events underlying their genesis and development are still not well defined, and therapeutic approaches based on the genetics of these tumors are currently lacking. In the present study we have used the immunoblotting technique to show that the p16(INK4A), Cdk6 and pRB proteins are differentially expressed in primary meningioma cells with 20-, 30- and 36-fold difference between the lowest and the highest levels of each protein, respectively. In addition, we present evidence that the level of the anti-apoptosis survivin protein is high in these benign tumors. Moreover, the annexin V-associated flow cytometry technique was used to show that 60% of meningioma cell cultures underwent apoptosis in response to both gamma-rays and cisplatin, and 50% of these cells exhibited significant sensitivity to hydroxyurea. These agents triggered apoptosis through the mitochondrial pathway, by increasing the Bax/Bcl-2 ratio. Interestingly, the induction of apoptosis following radiation and cisplatin was significant in all cells that expressed low levels of p16(INK4A), Cdk6 and pRB proteins. These data shed more light on the molecular biology of meningioma cells and suggest that survivin and proteins of the RB pathway could play a determinant role in the development and the treatment of meningiomas.
    Brain Research 02/2008; 1188:25-34. · 2.88 Impact Factor
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    ABSTRACT: Although meningiomas represent the most common class of tumors of the central nervous system, the molecular events underlying their genesis and development are still not well defined. In the present study we have used the immuno-blotting technique to study the expression level of the tumor suppressor proteins p53, p21 and PTEN in primary meningioma cells. We have also studied the induction of p21 and p53 in response to both UV light and gamma-rays. We present evidence that the p53/p21-dependent gamma-ray signaling pathway is defective in 5 out of 8 (62%) of these cells. Furthermore, we have shown that the tumor suppressor p21, p53 and PTEN proteins are differently expressed in these cells, with up to 40-folds difference between the lowest and the highest levels of each protein. These results suggest that the tumor suppressors p53/p21 signaling pathway and PTEN play important roles in the development of benign meningiomas.
    Journal of Neuro-Oncology 06/2007; 83(1):9-15. · 3.12 Impact Factor
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    ABSTRACT: Tuberculosis (TB) of the central nervous system (CNS) is still prevalent in many developing countries. Tuberculoma is always considered in the differential diagnosis of enhancing intra-axial lesions of the brain. Brain tuberculomas can present in many different clinical and radiological patterns, disseminated or miliary brain tuberculomas are very rare. We describe the case of a 25-year-old immunocompetent female with miliary brain tuberculomas. She presented with a history of progressive headache and unsteady gait. Serial Magnetic resonance imaging (MRI) studies revealed growing, multiple small enhancing lesions in the brain, most lesions measured approximately 2mm in diameter, in both the supratentorial and infratentorial compartments. Her investigation failed to reveal any evidence of TB outside the CNS. Open biopsy revealed multiple caseating granulomas and mycobacterin tuberculosis was cultured. She improved clinically and radiologically after starting anti-tuberculous pharmacotherapy. The clinical course, radiological images and pathological studies of this patient are presented. In conclusion miliary brain tuberculomas are rare and unique clinical and radiological entity. It may affect immunocompetent individuals with no other signs of other systemic involvement.
    Clinical Neurology and Neurosurgery 07/2006; 108(4):411-4. · 1.23 Impact Factor
  • Nabeel Alnaghmoosh, Ahmed Alkhani
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    ABSTRACT: Colloid cysts are uncommon in children. They occur more frequently in young adults. This is a retrospective study on all pediatric patients (<or=18 years) with colloid cysts treated surgically in our institute between 1977 and 2005. A total of 43 patients with colloid cyst were treated surgically. Seven pediatric patients (16% of the total number of patients) were identified. Patients' ages ranged from 6 to 18 years (mean of 14.1+/-4.67). They all presented clinically with symptoms and signs of increased intracranial pressure. Radiologically, the cyst size ranged from 10 to 25 mm (mean of 16.1+/-5.2). All patients had either diagnostic computed tomography (CT) or magnetic resonance imaging (MRI), or both. The colloid cysts appeared hyperdense on CT in five patients (83%) and isodense in one (six available studies). On MRI, all (five available studies) lesions were hyperintense on T2-weighted images. All seven patients had complete cyst resection. Either transcortical (five patients) or transcallosal approaches (two patients) was used in the surgical resection. There was no mortality. One patient developed a delayed cerebrospinal fluid leak related to hydrocephalus, and another patient developed a delayed postoperative seizure. The radiological findings supported the aggressive clinical scenario of these lesions in the pediatric group of patients. In conclusion, colloid cysts can occur in children. They are associated with more aggressive clinical and radiological patterns. Early surgical intervention is highly recommended.
    Child s Nervous System 06/2006; 22(5):514-6. · 1.24 Impact Factor
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    ABSTRACT: To address the limitations of standard electromyography (EMG) facial nerve monitoring techniques by exploring the novel application of multi-pulse transcranial electrical stimulation (mpTES) to myogenic facial motor evoked potential (MEP) monitoring. In 76 patients undergoing skull base surgery, mpTES was delivered through electrodes 1cm anterior to C1 and C2 (M1-M2), C3 and C4 (M3-M4) or C3 or C4 and Cz (M3/M4-Mz), with the anode contralateral to the operative side. Facial MEPs were monitored from the orbicularis oris muscle on the operative side. Distal facial nerve excitation was excluded by the absence of single pulse responses and by onset latency consistent with a central origin. M3/M4-Mz mpTES (n=50) reliably produced facial MEPs while M1-M2 (n=18) or M3-M4 (n=8) stimulation produced 6 technical failures. Facial MEPs could be successfully monitored in 21 of 22 patients whose proximal facial nerves were inaccessible to direct stimulation. Using 50, 35 and 0% of baseline amplitude criteria, significant facial deficits were predicted with a sensitivity/specificity of 1.00/0.88, 0.91/0.97 and 0.64/1.00, respectively. Facial MEPs can provide an ongoing surgeon-independent assessment of facial nerve function and predict facial nerve outcome with sufficiently useful accuracy. This method substantially improves facial nerve monitoring during skull base surgery.
    Clinical Neurophysiology 04/2005; 116(3):588-96. · 3.14 Impact Factor
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    ABSTRACT: Venous angiomas` also known as deep vein anomalies (DVA), are one of the well-described brain vascular malformations. Frequently they are diagnosed as an incidental finding on neuroimaging (CT or MRI). A DVA may present as a single enhancing venous channel or as a large vascular abnormality illustrated on cerebral angiogram. Such a large DVA may mimic other intracranial lesions that mandate surgical intervention. We describe the radiological findings on CT, MRI, MRA and cerebral angiography of a 26-year-old male who presented with a few months` history of recurrent attacks of light-headiness, dizziness and slurring of speech that usually lasted for 2 minutes and resolved spontaneously. Cerebral angiography illustrated enlarged medullary veins draining into a central venous trunk then into the superior sagittal sinus resembling a caput medusa sign. Large DVAs may present radiologically as a brain lesion. Early recognition of these anomalies would avoid unnecessary or harmful intervention of this, otherwise, benign pathology.
    Neurosciences 04/2005; 10(2):177-9. · 0.32 Impact Factor
  • Ahmed M Alkhani, Ahmed J Al-Zahrani
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    ABSTRACT: We present a case of intradural multiple ring-enhancing lesions in a 20-year-old male with symptoms and signs of progressive spastic paraparesis. An MRI of the thoracolumbar area showed 2 peculiar ring-enhancing lesions, at the level of T12 and L1. The differential diagnosis includes inflammatory or infectious lesions in addition to rare cystic tumors. The patient underwent surgical resection of the 2 lesions with an uneventful perioperative course. Histologically, the diagnosis was consistent with cystic schwannomas.
    Neurosciences 01/2005; 10(1):101-2. · 0.32 Impact Factor
  • Ahmed M Alkhani, Abdulsattar H Ghomraoui
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    ABSTRACT: To obtain an appraisal for the use of methylprednisolone (MP) in the early management of acute spinal cord injury (SCI) in our health system and the attitude to its use. A printed questionnaire on MP in acute SCI was distributed to all major spinal and neurosurgical centers in Riyadh, Kingdom of Saudi Arabia between October and November 2001. A total of 31 replies were collected for statistical analysis. There were 23 replies from doctors (74%) who see 5 or more cases of acute SCI per year. Sixteen doctors (53%) use MP in acute SCI (National Acute Spinal Cord Injury Studies [NASCIS] protocol) regularly, 11 (37%) use it occasionally and 3 (10%) never use it. The use of MP in acute SCI was suggested as a standard of care by 16%, recommended only by 48% and considered optional by 35%. In addition, a review of the literature on the results of the NASCIS I, II and III was conducted. Our results confirm the diversities in clinical practice regarding the use of MP in acute SCI. They also raise the issue of the need for specialized centers in spinal trauma with a unified protocol for treatment throughout the Kingdom.
    Neurosciences 07/2003; 8(3):161-4. · 0.32 Impact Factor
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    ABSTRACT: Ependymoma is the most frequently encountered intramedullary tumor. Total surgical resection is the therapeutic modality of choice whenever possible, but carries a significant risk of morbidity. This study was designed to define prognostic factors that affect clinical outcome after surgical resection of spinal intramedullary ependymoma. The medical records, radiological and pathological studies of all patients with intramedullary spinal ependymomas treated surgically in one institution were reviewed retrospectively. Spinal myxopapillary ependymomas were excluded. In a multivariable regression analysis, possible prognostic factors were correlated with the 6-month postoperative neurological status using McCormick's grading scale. Surgery was performed on 17 patients (14 males, 3 females, mean age of 42+/-15 years) with spinal ependymoma. The cervical spine was the most common tumor location (71%). Total surgical resection of the tumor was achieved in 11 cases (65%). Intraoperative neurophysiological monitoring was used in 8 cases (47%). Postoperatively, 11 patients (65%) either improved or had no change from their preoperative neurological status. None of the 11 totally resected tumors has shown evidence of recurrence in a follow-up period range from 8-120 months (median, 33 months). Of several possible prognostic factors, the only statistically significant correlation identified with the 6-month postoperative neurological status was the preoperative McCormick grading score. Preoperative neurological status was the only statistically significant factor in determining the postoperative neurological outcome of patients with spinal intramedullary ependymomas. Early diagnosis and referral for surgery to specialized centers are recommended as controllable factors in improving outcome.
    Annals of Saudi medicine 28(2):109-13. · 1.10 Impact Factor