Barrie J. Hurwitz

Jugular bulb saturation and cognitive dysfunction after cardiopulmonary bypass

Inadequate cerebral oxygenation during cardiopulmonary bypass may lead to postoperative cognitive dysfunction in patients undergoing cardiac operations. A psychological test battery was administered to 255 patients before cardiac operation and just before hospital discharge. Postoperative impairment was defined as a decline of more than one standard deviation in 20% of tests. Variables significantly (p < 0.05) associated with postoperative cognitive impairment are baseline psychometric scores, largest arterial-venous oxygen difference, and years of education. Jugular bulb hemoglobin saturation is significant if it replaces arterial-venous oxygen difference in the model. Factors correlated with jugular bulb saturation at normothermia were cerebral metabolic rate of oxygen consumption (r = -0.6; p < 0.0005), cerebral blood flow (r = 0.4; p < 0.0005), oxygen delivery (r = 0.4; p < 0.0005), and mean arterial pressure (r = 0.15; p < 0.05). Three measures were significantly related to desaturation at normothermia and at hypothermia as well: greater cerebral oxygen extraction, greater arterial-venous oxygen difference, and lower ratio of cerebral blood flow to arterial-venous oxygen difference. We conclude that cerebral venous desaturation occurs during cardiopulmonary bypass in 17% to 23% of people and is associated with impaired postoperative cognitive test performance.

Degeneration of the central nervous system associated with celiac disease

The following report describes a 57-year-old man with celiac disease who developed a progressive and fatal neurologic disorder despite intensive medical and nutritional care. The clinical and pathological CNS findings in this patient are compared with those of 9 previously reported patients with well documented celiac disease in whom a progressive CNS disorder was carefully studied both pre-and postmortem. An entity of CNS degeneration associated with celiac disease appears to emerge from the study of these 10 cases. This disorder affects predominantly the cerebellum, deep gray masses, certain brain stem nuclei, and spinal cord; its cause and pathogenesis are unknown.

The diagnosis of multiple sclerosis and the clinical subtypes

The diagnosis of multiple sclerosis (MS) requires objective findings referable to the central nervous system. A wide differential diagnosis often has to be considered. Magnetic resonance imaging and electrophysiologic and cerebrospinal fluid studies can all contribute to an early definitive diagnosis. The McDonald diagnostic criteria for MS (2005) are the currently recognized MS diagnostic criteria. The clinical subtypes of MS and their diagnosis are discussed in this article. Being informed of the diagnosis may be a stressful experience for the patient and this is also dealt with.

Tolerability and safety profile of 12- to 28-week treatment with interferon beta-1b 250 and 500 µg QOD in patients with relapsing-remitting multiple sclerosis: A multicenter, randomized, double-blind, parallel-group pilot study

BACKGROUND It is not known whether the currently available treatment regimen of interferon beta-1b (IFNbeta-1b) 250 microg provides the maximum benefit possible in the treatment of relapsing-remitting multiple sclerosis (RRMS), or whether higher doses of IFNbeta-1b will prove to be more beneficial. OBJECTIVE The objective of the present study was to evaluate the tolerability and safety profile of IFNbeta-1b 500 microg compared with the currently approved 250-microg dose. METHODS A multicenter, randomized, double-blind, parallel-group pilot study was carried out to compare IFNbeta-1b 250 microg with IFNbeta-1b 500 microg, both self-administered SC QOD for >or=12 weeks in patients with RRMS. Patients in both groups started with 25% (0.25 mL) of their final dose and were scheduled to increase the dose by 0.25 mL every 2 weeks, so that the full dose (1.0 mL, 250 microg or 500 microg) would be reached by week 7. The primary outcome measure was the percentage of patients experiencing each of the following adverse events (AEs): influenza-like symptoms (general term used to code the presence of >1 symptom typical of influenza), fever, myalgia, asthenia, headache, injection-site reactions, injection-site pain, or liver or hematologic abnormalities. All patients underwent a priori magnetic resonance imaging (MRI) with 0.1 mmol/kg gadolinium (Gd)-diethylenetriaminepentaacetic acid as contrast medium at screening and at week 12. MRI evaluation was included as a safety measure to monitor for excessive new disease not visible through clinical symptoms. RESULTS Seventy-seven patients were assessed for inclusion in the study. Of these, 6 patients were screening failures and the remaining 71 were randomized to treatment (38-250 and 33-500 microg IFNbeta-1b). The uneven numbers in the groups were a consequence of the randomization process. Two patients in the 250-microg group (withdrawal of consent) and 1 in the 500-microg group (not completing follow-up visit) prematurely discontinued medication. The demographic characteristics were not significantly different between the 250-microg (n=38; mean [SD] age, 37.9 [8.3] years; weight, 83.5 [19.0] kg; height, 168.4 [9.3] cm) and 500-microg (n=33; mean [SD] age, 37.8 [7.7] years; weight, 82.3 [19.5] kg; height, 169.9 [10.5] cm) treatment groups. The patients in both groups were mostly white (87% and 73%, respectively). Baseline Expanded Disability Status Scale scores also were not significantly different between the 2 groups (mean [SD] score, 2.8 [1.4] vs 2.0 [1.4], respectively). In the IFN(2)-1b 250-microg group, 97% of the patients titrated to the full dose at some point during the course of the study, compared with 91% of the 500-microg group (P=NS). A dose-response effect was observed in some of the more frequent AEs (no. [%]) that included influenza-like syndrome (250-microg group, 13 [34] vs 500-microg group, 16 [48]), asthenia (13 [34] vs 16 [48], respectively), headache (12 [32] vs 12 [36]), myalgia (10 [26] vs 13 [39]), hypesthesia (10 [26] vs 11 [33]), nausea (6 [16] vs 8 [24]), paresthesia (6 [16] vs 8 [24]), myasthenia (4 [11] vs 8 [24]), chills (3 [8] vs 6 [18]), depression (3 [8] vs 5 [15]), back pain (2 [5] vs 5 [15]), increased liver enzymes (4 [11] vs 6 [18]), lymphopenia (4 [11] vs 3 [9]), fever (2 [5] vs 4 [12]), and pain in extremities (1 [3] vs 4 [12]). The between-group incidence of injection-site reactions was not significantly different. No new or unexpected AEs were recorded. Changes in MRI parameters between screening and 12 weeks were not significantly different between dose groups; these included median T2 lesion volume, median Gd-enhanced lesion volume, median Gd-enhanced lesion number, and mean number of newly active lesions. CONCLUSIONS IFNbeta-1b 500 microg administered SC QOD was generally well tolerated in these patients with RRMS. Large, randomized controlled studies are needed to determine if there are significant differences in MRI end points between the 250- and 500-microg doses.

Optimizing Outcomes in Multiple Sclerosis – A Consensus Initiative

Background Initiation of immunomodulators in patients experiencing a clinically isolated syndrome (CIS) may delay progression to clinically definite MS. However, lack of consensus remains on many issues affecting optimal management of MS. Method A panel of 21 MS experts met during 9 meetings to explore key issues in MS and CIS. Meetings addressed 3 phases: 1. CIS definition and diagnosis; 2. initial therapy; and 3. monitoring disease progression and treatment efficacy. Newsletters covering each phase were sent to 5000 U.S.-based neurologists who were invited to participate in an online survey on key issues. Results Most panel members agreed that early treatment may minimize neurodegeneration and most would recommend it for patients; that a dose-response relationship exists for beta-interferon therapy; that more aggressive therapy was most effective early in the disease course; and, that MRI has a role in monitoring disease progression. In face of suboptimal response, most would switch patients to a different therapy; while combination therapy would be reserved for those failing monotherapy regimes. Most online survey respondents agreed with these positions. Conclusions There was uniform consensus from this panel of MS experts that early initiation of immunomodulator therapy was beneficial for CIS patients.