Christina Caon
Wayne State University
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Featured researches published by Christina Caon.
Multiple Sclerosis Journal | 2006
Corey C. Ford; Kenneth P. Johnson; R. P. Lisak; Hillel Panitch; G. Shifroni; Jerry S. Wolinsky; Clyde Markowitz; Amy A. Pruitt; Dorothea Pfohl; Gary A. Rosenberg; Elida Greinel; Omar Khan; Deena Lisak; Alexandros Tselis; John Kamholz; Christina Caon; Lawrence W. Myers; W. Baumhefner; Ricki Klutch; Christopher T. Bever; Eleanor Katz; John Rose; James Burns; Connie Kawai; Andrew D. Goodman; Steven R. Schwid; Mary Petrie; Jana Preiningerova; Silva Markovic Plese; George Blanco
A decade of continuous glatiramer acetate (GA) use by relapsing remitting multiple sclerosis (RRMS) patients was evaluated in this ongoing, prospective study, and the neurological status of ‘Withdrawn’ patients was assessed at a 10-year long-term follow-up (LTFU) visit. Modified intention-to-treat (mITT, n=232) patients received ≥ 1 GA dose since 1991; ‘Ongoing’ patients (n=108) continued in November 2003. Of 124 patients, 50 Withdrawn patients returned for LTFU. Patients were evaluated every six months (EDSS). Mean GA exposure was 6.99, 10.1 and 4.26 years for mITT, Ongoing, and Withdrawn/LTFU patients, respectively. While on GA, mITT relapse rates declined from 1.18/year prestudy to ∼1 relapse/5 years; median time to ≥ 1 EDSS point increase was 8.8 years; mean EDSS change was 0.739±1.66 points; 58% had stable/improved EDSS scores; and 24, 11 and 3% reached EDSS 4, 6 and 8, respectively. For Ongoing patients, EDSS increased 0.509±1.65; 62% were stable/improved; and 24, 8 and 1% reached EDSS 4, 6 and 8, respectively. For Withdrawn patients at 10-year LTFU, EDSS increased 2.249±1.86; 28% were stable/improved; and 68, 50 and 10% reached EDSS 4, 6 and 8, respectively. While on GA nearly all patients (mean disease duration 15 years) remained ambulatory. At LTFU, Withdrawn patients had greater disability than Ongoing patients.
Multiple Sclerosis Journal | 2005
Omar Khan; Yimin Shen; Christina Caon; Fen Bao; Wendy Ching; Melissa Reznar; Alyssa Buccheister; Jiani Hu; Zahid Latif; Alexandros Tselis; Robert P. Lisak
Glatiramer acetate (GA) is a disease-modifying therapy for relapsing-remitting multiple sclerosis (RRMS) with several putative mechanisms of action. Currently, there is paucity ofin vivo human data linking the well-established peripheral immunologic effects of therapy with GA to its potential effects inside the central nervous system (CNS). Brain proton magnetic resonance spectroscopy (MRS) allows in vivo examination of axonal integrity by quantifying the resonance intensity of the neuronal marker N-acetylaspartate (NAA). In a pilot study to investigate the effect of GA on axonal injury, we performed combined brain magnetic resonance imaging (MRI) and MRS studies in 18 treatment naïve RRMS patients initiating therapy with GA at baseline and annually for two years on therapy. A small group of four treatment naïve RRMS patients, electing to remain untreated, served as controls. NAA/Cr was measured in a large central brain volume of interest (VOI) as well as the normal appearing white matter (NAWM) within the VOI. After two years, NAA/Cr in the GA-treated group increased significantly by 10.7% in the VOI (2.179±0.26 versus 1.969±0.24, P=0.03) and by 7.1% in the NAWM (2.239±0.26 versus 2.089±0.31, P=0.04). In the untreated group, NAA/Cr decreased by 8.9% at two years in the VOI (2.019±0.16 versus 1.839±0.21, P=0.03) and 8.2% in the NAWM (2.079±0.24 versus 1.909±0.29, P=0.03). Our data shows that treatment with GA leads to axonal metabolic recovery and protection from sub-lethal axonal injury. These results support an in situ effect of GA therapy inside the CNS and suggest potential neuroprotective effects of GA.
European Journal of Neurology | 2006
Christina Caon; M. Din; W. Ching; Alex Tselis; Robert P. Lisak; Omar Khan
We examined the clinical course after switching disease‐modifying therapy (DMT) in patients with relapsing–remitting multiple sclerosis (RRMS). Eighty‐five consecutive RRMS patients who received weekly interferon beta‐1a (IFN beta‐1a) 6 MU i.m. for at least 18 months were enrolled. Baseline annualized relapse rate (ARR) for the 2 years prior to initiating therapy with IFN beta‐1a was obtained from charts. All 85 patients received treatment with IFN beta‐1a at 6 MU i.m. weekly for 18–24 months (mean 19.7 months). Treatment with IFN beta‐1a reduced the mean ARR from 1.41 to 1.23 (P = 0.005). All 85 patients were then switched to glatiramer acetate (GA) 20 mg s.c. daily and prospectively followed up for 36–42 months (mean 37.5 months). Patients were switched because of persistent clinical disease activity (n = 62) or persistently unacceptable toxicity (n = 23) as determined by the treating neurologist. Treatment with GA reduced the mean ARR from 1.23 to 0.53 (P = 0.0001). Subgroup analysis showed that in patients who were switched because of lack of efficacy (n = 62), the mean ARR was reduced from 1.32 on IFN beta‐1a to 0.52 on GA (P = 0.0001). In contrast, in patients who switched because of persistent toxicity (n = 23), the mean ARR was reduced from 0.61 on IFN beta‐1a to 0.47 on GA (P, non‐significant). Our observations suggest that clinical observations such as relapse rate and tolerability may be used as criteria for switching DMT in clinical practice. More definitive consensus criteria incorporating magnetic resonance imaging and clinical observations for defining optimal response and tolerability need to be developed for the routine clinical management of RRMS patients receiving DMT.
European Journal of Neurology | 2008
Jai Perumal; Christina Caon; S. Hreha; R. Zabad; Alexandros Tselis; Robert P. Lisak; Omar Khan
Background: A short course of intravenous methylprednisolone (IVMP) followed by oral prednisone taper (OPT) is often used for the treatment of relapses in multiple sclerosis (MS). We examined the effect of IVMP plus OPT compared with IVMP only on neurologic disability 1 year after treatment of a relapse in patients with relapsing–remitting multiple sclerosis..
Multiple Sclerosis Journal | 2005
Paul O'Connor; David Miller; Katherine Riester; Minhua Yang; Michael Panzara; Catherine Dalton; Katherine A. Miszkiel; Omar Khan; George Rice; William A. Sheremata; Gareth J. Barker; David G. MacManus; C. Webb; C. Middleditch; S. Lewis; T. Pepple; E. Riddle; C. Coombs; Mark A. Agius; David P. Richman; J. Adams; M. Buonocore; Jinan Al-Omaishi; K. Markopoulou; Kathleen Healey; P. Sorensen; David W. Bates; J. Forsyth; J. Curlis; P. English
Background: Natalizumab, a humanized monoclonal IgG4 antibody, is an a4-integrin antagonist, which inhibits the migration of inflammatory cells into the central nervous system, a key pathogenic mechanism in multiple sclerosis (MS). In a six month, phase II clinical trial of patients with relapsing MS, natalizumab significantly reduced the formation of new gadolinium-enhanced (Gd +) lesions and the number of clinical relapses. Objective: To investigate the relationship of historical relapse rate and new Gd+ lesion number with subsequent MS disease activity and natalizumab treatment in the phase II study. Methods: Patients who participated in the phase II study were stratified into subgroups according to: (i) the number of relapses in the two years prior to entry into the study: 2 relapses (n=108), 3 relapses (n=57), and-3 relapses (n=48); (ii) the number of new Gd+ lesions at baseline (Month 0): 0 (n=129), 1-2(n=50), and >2(n=33). Relapses and new Gd+ lesions during the treatment phase of the trial were determined and compared for each subgroup. Results: Both the prestudy relapse rate and number of new Gd+ lesions at baseline were related to the subsequent risk of a relapse; baseline number of Gd+ lesions was related to the likelihood of subsequent new Gd+ lesion formation. There was a lower proportion of subjects with an on-study relapse and fewer new Gd+ lesions in all natalizumab-treated subgroups when compared with their placebo counterpart; the difference was most apparent in the subgroups of patients with >3 relapses in the two years prior to study entry and >2 new Gd+ lesions at Month 0. Conclusions: There was a lower proportion of subjects with an on-study relapse in natalizumab-treated patients, particularly in those with a more active disease at study entry. Larger ongoing phase III studies will allow more definitive investigation of these preliminary subgroup findings.
JAMA Neurology | 2009
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
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.
Pediatric Neurology | 2009
Aaron Boster; Christina Endress; S. Hreha; Christina Caon; Jai Perumal; Omar Khan
Pediatric-onset multiple sclerosis is now recognized, but the association with ethnicity has not been well studied. In a retrospective review at a major teaching facility, 46 pediatric-onset multiple sclerosis patients were identified; of these, 24 were African-American black and 19 were European-origin white. Both groups were similar in mean age at onset (black, 13.6 +/- 3.36 years; white, 13.68 +/- 3.42 years) and total duration of follow-up (black, 42.7 +/- 43.5 months; white, 38.2 +/- 35.3 months), with no significant difference in time to onset of disease-modifying therapy (black, 11.2 +/- 4.7 months; white, 12.4 +/- 5.1 months). The percentage of females was higher in the black than in the white group (83% vs 47%; P = 0.014). The annualized relapse rate was significantly higher in the black than in the white group (1.80 +/- 1.14 vs 1.13 +/- 0.50; P < 0.001). These findings are consistent with data suggesting a more aggressive disease phenotype among African-American blacks with adult-onset multiple sclerosis. Larger multicenter studies are warranted to confirm the findings.
Journal of Neurology | 2008
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
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.