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Dive into the research topics where Imad Zak is active.

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Featured researches published by Imad Zak.


Annals of Neurology | 2010

Chronic Cerebrospinal Venous Insufficiency and Multiple Sclerosis

Omar Khan; Massimo Filippi; Mark S. Freedman; Frederik Barkhof; Paula Dore-Duffy; Hans Lassmann; Bruce D. Trapp; Amit Bar-Or; Imad Zak; Marilyn J. Siegel; Robert P. Lisak

A chronic state of impaired venous drainage from the central nervous system, termed chronic cerebrospinal venous insufficiency (CCSVI), is claimed to be a pathologic phenomenon exclusively seen in multiple sclerosis (MS). This has invigorated the causal debate of MS and generated immense interest in the patient and scientific communities. A potential shift in the treatment paradigm of MS involving endovascular balloon angioplasty or venous stent placement has been proposed as well as conducted in small patient series. In some cases, it may have resulted in serious injury. In this Point of View, we discuss the recent investigations that led to the description of CCSVI as well as the conceptual and technical shortcomings that challenge the potential relationship of this phenomenon to MS. The need for conducting carefully designed and rigorously controlled studies to investigate CCVSI has been recognized by the scientific bodies engaged in MS research. Several scientific endeavors examining the presence of CCSVI in MS are being undertaken. At present, invasive and potentially dangerous endovascular procedures as therapy for patients with MS should be discouraged until such studies have been completed, analyzed, and debated in the scientific arena. ANN NEUROL 2010;67:286–290


JAMA Neurology | 2009

Progressive Multifocal Leukoencephalopathy and Relapsing-Remitting Multiple Sclerosis: A Comparative Study

Aaron Boster; S. Hreha; Joseph R. Berger; Fen Bao; Ramya Penmesta; Alexandros Tselis; Christina Endress; Imad Zak; Jai Perumal; Christina Caon; Jose A. Vazquez; Kenneth L. Tyler; Michael K. Racke; Scott R. Millis; Omar Khan

OBJECTIVE To identify clinical and magnetic resonance imaging (MRI) features that distinguish progressive multifocal leukoencephalopathy (PML) from relapsing-remitting multiple sclerosis (RRMS). DESIGN Retrospective medical record review. SETTING Two urban teaching hospitals in Detroit, Michigan. Patients Forty-five confirmed PML cases and 100 patients with RRMS. MAIN OUTCOME MEASURES Clinical and MRI features distinguishing PML from RRMS. RESULTS Overall, monosymptomatic presentations were more common in multiple sclerosis (MS) than PML (85% vs 47%; P < .01). However, patients with PML presented more often with hemiparesis (24% vs 5%; P = .001) and altered mentation (19% vs 0%; P < .0001), whereas brainstem (2% vs 18%; P = .007) presentations were more common in patients with RRMS. Spinal cord and optic neuritis presentations were seen in 18% and 33% of patients with RRMS, respectively, but not in patients with PML (m < .0001). Brain MRI scans, available in 35 (78%) PML cases, revealed 7 lesion types. Large, confluent T2-weighted lesions (74% vs 2%; P < .0001) and deep gray matter lesions (31% vs 7%; P < .001) were more frequent in patients with PML than patients with RRMS. Crescentic cerebellar lesions (23% vs 0%; P < .001) were seen only in patients with PML. Gadolinium-enhancing (23%), transcallosal (9%), and periventricular (9%) lesions were noted in patients with PML. Brain magnetization transfer ratio (MTR) was low in both PML and MS lesions. However, normal-appearing brain tissue MTR in PML was higher than normal-appearing brain tissue MTR in RRMS (44.15% vs 41.04%; P = .002), suggesting that PML may be relatively more focal than MS. CONCLUSIONS There appear to be differences between the clinical and MRI characteristics of PML and RRMS, which may help distinguish new MS activity from PML. Magnetization transfer ratio studies may provide additional clues in improving early detection of PML in patients with preexisting MS and warrant further investigation.


Journal of Neuroimaging | 2008

Long-term study of brain 1H-MRS study in multiple sclerosis: Effect of glatiramer acetate therapy on axonal metabolic function and feasibility of long-term 1H-MRS monitoring in multiple sclerosis

Omar Khan; Yimin Shen; Fen Bao; Christina Caon; Alexandros Tselis; Zahid Latif; Imad Zak

Glatiramer acetate (GA) has several putative mechanisms of action with the potential of limiting sublethal axonal injury in the central nervous system (CNS). Brain proton magnetic resonance spectroscopy (1H‐MRS) allows in vivo examination of axonal integrity by quantifying the neuronal marker N‐acetylaspartate (NAA), often expressed as a ratio to creatine (Cr). We showed that treatment with GA led to improvement in NAA/Cr over a 2‐year period. We now report the results of this ongoing study after 4 years of annual brain 1H‐MRS examinations. Compared to baseline, at year 4, patients receiving continuous GA therapy showed a 12.7% increase in NAA/Cr and (P= .03) in the multivoxel brain volume of interest (VOI) studied and by 9.6% (P= .04) in the normal‐appearing white matter within the VOI. Three patients in the control group who began therapy with GA during the course of the study showed similar increases in NAA/Cr after the first year of therapy. These data support the long‐term effect of GA on maintaining axonal metabolic function and protection from sublethal injury as well as the feasibility of employing brain 1H‐MRS in long‐term investigative studies in MS.


Journal of Neurology | 2008

Acute transverse myelitis with normal brain MRI Long-term risk of MS

Jai Perumal; Rana Zabad; Christina Caon; Megan Mackenzie; Alexandros Tselis; Fen Bao; Zahid Latif; Imad Zak; Robert P. Lisak; Omar Khan

ObjectiveTo investigate the long-term risk of developing MS in patients presenting with acute transverse myelitis (ATM) and normal brain MRI scans at onset.MethodsWe studied 58 ATM patients with normal brain MRI at presentation for up to 5 years with serial neurologic and imaging studies. All patients underwent CSF analysis at onset which was defined positive if two or more IgG oligoclonal bands and/or elevated IgG index were present. Brain and spinal cord MRI scans were obtained every 6 months for the first 2 years, and annually thereafter unless the patient experienced a second neurologic attack different from the initial episode to confirm CDMS or there was demonstration of MRI lesions confirming dissemination in time and space to fulfill McDonald imaging criteria to diagnose MS.ResultsSeventeen of 58 (29%) patients developed MS of which 7 (41%) patients developed CDMS and 10 (59%) developed MS using McDonald Imaging Criteria. Mean time to CDMS by a second clinical attack was 11. 1 months compared to 19. 2 months by MRI lesions (P = 0. 03). None of the patients developed MS after 24 months of onset. All 17 patients who developed MS had positive CSF although 15 patients who had positive CSF did not develop MS during the 5 years of follow-up.ConclusionsThe majority of patients with ATM and normal brain MRI do not develop MS after 5 years of follow-up confirming the relatively low risk compared to patients with abnormal brain MRI scans. CSF is helpful in distinguishing patients more likely to develop MS. Compared to clinical attacks, serial imaging may not lead to an earlier diagnosis in ATM patients with normal brain MRI.


Journal of the Neurological Sciences | 2012

Effect of disease-modifying therapies on brain volume in relapsing-remitting multiple sclerosis: Results of a five-year brain MRI study

Omar Khan; Fen Bao; M. Shah; Christina Caon; Alexandros Tselis; Ronald Bailey; Bruce Silverman; Imad Zak

OBJECTIVE To compare the long-term effect of disease-modifying therapies (DMT) on brain volume loss in relapsing-remitting MS (RRMS) patients. METHODS We conducted a study to examine the effect of daily glatiramer acetate (GA), weekly low dose interferon beta (LD-IFNB), and high-dose high-frequency interferon beta disease (HD-IFNB) on brain volume loss over 5 years in RRMS patients. All patients were previously treatment naïve, had disease duration ≤5 years at the time of initiating DMT, and subsequently received the same DMT for 5 years continuously. The percentage change in brain volume (PCBV) was measured using fully automated software. MRI analysis was performed blinded to treatment allocation. RESULTS The adjusted PCBV from baseline to year 5 was -2.27% in GA, -2.62% in LD-IFNB, and -3.21% in the HD-IFNB groups (-2.27 vs -2.62, p=0.0036; -2.27 vs -3.21, p<0.0001; -2.62 vs -3.21, p<0.0001). These data remained unchanged from year 1 to year 5, after adjusting for pseudoatrophy in the first year. A group of RRMS patients that remained untreated for a period ranging from 8 to 24 months, served as controls. All treatment groups were significantly better than the rate of projected brain volume loss in the untreated group over 5 years (p<0.0001). CONCLUSIONS Global brain volume loss is a dynamic process even in relatively early RRMS patients that occurs despite intervention with therapy. However, all DMT significantly reduced the loss of brain volume compared to no treatment. The GA-treated group experienced the least reduction in brain volume over 5 years, compared to the LD-IFNB and HD-IFNB treated groups. These differences could be partly related to the immunologic consequences of GA therapy in RRMS.


Clinical Nuclear Medicine | 1995

Tc-99m MIBI scintigraphic detection of metastatic insular thyroid carcinoma.

Imad Zak; James E. Seabold; Nelson J. Gurll

Thallium-201 and, recently, Tc-99m MIBI have been used in conjunction with I-131 scintigraphy for follow-up of patients with well-differentiated thyroid cancer. Insular carcinoma of the thyroid is a fairly aggressive thyroid neoplasm that is believed to arise from follicular cells and usually concentrates I-131. The authors report a patient with recurrent insular thyroid carcinoma in whom bilateral adrenal and lung metastatic lesions developed 3 years after ablative I-131 therapy for cervical lymph node and skeletal metastases. Tc-99m MIBI planar and SPECT images demonstrated these new lesions better than pretherapy I-131 scintigraphy and affords an imaging technique for post-I-131 therapy follow-up that does not require withholding thyroid hormone suppression.


Journal of the Neurological Sciences | 2009

Rare sensory and autonomic disturbances associated with vitamin B12 deficiency.

Preeti Puntambekar; Maysaa Basha; Imad Zak; Ramesh Madhavan

Vitamin B12 deficiency is an important nutritional disorder causing neurological manifestations of myelopathy, neuropathy and dementia. Sub-acute combined degeneration (SCD) with involvement of the posterior columns in the cervical and thoracic cord is a common presentation of this disorder. In this case report, we describe a 43 year old woman with pernicious anemia and myelopathy with atypical clinical features. The patient presented with motor symptoms, a sensory level and bladder dysfunction. She had severe autonomic disturbances including an episode of unexplained bronchospasm, which has not been previously reported as a manifestation of vitamin B12 deficiency. We review the literature regarding these rarely reported features of vitamin B12 deficiency, and discuss aspects of management of this reversible condition. We emphasize the importance of awareness of autonomic disturbances in B12 deficient individuals.


Clinical Nuclear Medicine | 2004

Retroperitoneal malignant peripheral nerve sheath tumor: Evaluation with serial FDG-PET

Subhash Chander; Steven Westphal; Imad Zak; David A. Bloom; Alkis P. Zingas; Richard Joyrich; Peter Littrup; Jeffrey W. Taub; Todd M. Getzen

Retroperitoneal malignant peripheral nerve sheath tumor (MPNST), a rare type of neurogenic tumor, was diagnosed in a 14-year-old girl with a history of neurofibromatosis type 1 (NF1). Immunochemistry demonstrated spindle cells positive for S-100 protein. The patient had multiple tumor recurrences and she was evaluated with serial F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET). A tumor in the right iliac wing showed increased FDG uptake on PET. FDG-PET played an important role in therapy planning and subsequent follow up. This case emphasizes the important role FDG-PET could play in the staging, restaging, and posttherapy follow up of MPNST.


Multiple sclerosis and related disorders | 2015

Spinal cord atrophy in multiple sclerosis and relationship with disability across clinical phenotypes

Evanthia Bernitsas; Fen Bao; Navid Seraji-Bozorgzad; Jessica Chorostecki; Carla Santiago; Alexandros Tselis; Christina Caon; Imad Zak; Scott R. Millis; Omar Khan

BACKGROUND Several studies have shown a relationship between spinal cord atrophy and clinical disability in patients with multiple sclerosis (MS). OBJECTIVES We examined the correlation between cervical cord cross-sectional area at the C2 vertebral level (CSA-C2) and the expanded disability status scale (EDSS) in patients with relapsing-remitting and progressive forms of MS. The latter included both secondary and primary progressive MS patients. METHODS A total of 150 patients with MS were recruited from the Wayne State University MS clinic. Ninety-three had relapsing-remitting MS and 57 patients had progressive MS. MRI scan of the cervical cord was obtained for each patient. Correlation studies and multivariate regression analysis was performed, blinded to clinical status. RESULTS The mean age was 41.3 year old, 64.6% were women, mean disease duration was 11.2 years, CSA-C2 was 80.2mm(2) and mean EDSS was 3.8. There was significant correlation between CSA-C2 and EDSS (r -0.75, p<0.0001). Sub-group analysis showed CSA-C2 was 68.6mm(2) and 87.3mm(2) in the progressive and relapsing-remitting groups, respectively (p<0.0001). Multivariable regression showed that CSA-C2 was a significant predictor of disability independent of disease duration, and phenotype. CONCLUSIONS Our study demonstrates that CSA-C2 has a strong correlation with clinical disability in both RRMS and progressive MS. Greater spinal cord atrophy was seen in patients with progressive than relapsing-remitting MS. CSA-C2, disease duration, and phenotype are independent predictors of disability.


Movement Disorders | 2015

Longitudinal study of the substantia nigra in Parkinson disease: A high-field (1) H-MR spectroscopy imaging study.

Navid Seraji-Bozorgzad; Fen Bao; Edwin George; Shana Krstevska; Veronica Gorden; Jessica Chorostecki; Carla Santiago; Imad Zak; Christina Caon; Omar Khan

The value of biomarkers in early diagnosis and development of therapeutics in Parkinsons disease (PD) is well established.

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Omar Khan

Wayne State University

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Fen Bao

Wayne State University

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