Central scalp projection of the N30 SEP source activity after median nerve stimulation

Conflicting results have been reported about abnormalities of the N30 somatosensory evoked potential (SEP) in movement disorders. In these studies, the N30 amplitude was measured in the frontal scalp region. Our aim was to identify the scalp electrodes recording the genuine activity of the N30 generator. In 18 subjects, we recorded the scalp SEPs from 19 electrodes and found a negative potential around 30 ms reaching its maximal amplitude in the frontal region. However, neither simple visual inspection of the frontal traces nor topographic analysis could distinguish the N24 from the N30 component of the frontal negativity. Brain electrical source analysis of SEPs showed that a four dipolar source model could well explain the scalp SEP distribution. We calculated the scalp field distributions of the source activities as modeled from the scalp recordings and observed that the maximal field distribution reflecting the activity of the N30 source was in the central region, whereas that reflecting the N24 source activity was frontal. We conclude that the negative response recorded around 30 ms in the central traces represents "genuine" N30 source activity, whereas the frontal negativity, which is higher in amplitude, is a mixture of the activities of both the N30 and N24 sources. (C) 2000 John Wiley & Sons, Inc. Muscle Nerve 23: 353-360, 2000

Clinical and neurophysiological abnormalities before and after reconstruction of the anterior cruciate ligament of the knee

Objectives - We aimed to study knee proprioception and somatosensory evoked potentials (SEPs) to stimulation of the common peroneal nerve (CPN) in 7 patients with lesion of the anterior cruciate ligament (ACL) before and after ACL reconstruction. Materials and methods - We recorded the spinal N14 and scalp P27 potentials in 5 patients, while in the remaining 2 patients we calculated scalp SEP maps by 20 electrodes. The knee proprioception was tested by comparing the sensitivity to movement of both the knees. Results - Before surgery, all patients showed decreased knee position sense and lack of the cortical P27 potential on the side of the ACL lesion. Arthroscopic reconstruction of the ligament improved neither the knee proprioception nor the somatosensory central conduction. Conclusion - We suggest that the loss of the knee mechanoreceptors can be followed by modifications of the central nervous system, which are not compensated by other nervous structures

Effects of immunomodulatory treatment with subcutaneous interferon beta-1a oncognitive decline in mildly disabled patients with relapsing-remitting multiple sclerosis

The objective of this study was to assess the effects of subcutaneous (sc) interferon beta-1a (IFNbeta-1a) on cognition in mildly disabled patients with relapsing-remitting multiple sclerosis (RRMS). Patients aged 18-50 years with RRMS (McDonald criteria; Expanded Disability Status Scale score <or=4.0) were assigned IFNbeta therapy at the physician's discretion and underwent standardized magnetic resonance imaging, neurological examination and neuropsychological testing at the baseline and regular intervals for up to three years. This analysis included 459 patients who received sc IFNbeta-1a (44 mcg: n = 236; 22 mcg: n = 223; three-year follow up was available for 318 patients). The hazard ratio for cognitive impairment over three years (44 mcg versus 22 mcg) was 0.68 (95% confidence interval [CI]: 0.480-0.972), suggesting a 32% lower risk with the higher dose treatment. At year 3, the proportion of patients who were cognitively impaired increased slightly from 23.5% at the baseline to 24.8% in the IFNbeta-1a 22 mcg treatment group, but remained stable at 15.2% in the IFNbeta-1a 44 mcg treatment group. The proportion of patients with cognitive impairment at year 3 was significantly higher in the 22 mcg group than in the 44 mcg group (P = 0.03), although a trend was also seen at the baseline (P = 0.058). Multivariate logistic regression (corrected for baseline cognitive deficits) indicated that treatment with the higher dose of IFNbeta-1a was predictive of lower cognitive impairment at three years (odds ratio: 0.51, 95% CI: 0.26-0.99) compared with the lower dose of IFNbeta-1a. These findings suggest that sc IFNbeta-1a may have dose-dependent cognitive benefits in mildly disabled patients with RRMS, and may support early initiation of high-dose IFNbeta-1a treatment

Subcutaneous interferon \u3b2-1a may protect against cognitive impairment in patients with relapsing-remitting multiple sclerosis: 5-year follow-up of the COGIMUS study

Objective: To assess the effects of subcutaneous (sc) interferon (IFN) -1a on cognition over 5 years in mildly disabled patients with relapsing\u2013remitting multiple sclerosis (RRMS). Methods: Patients aged 18\u201350 years with RRMS (Expanded Disability Status Scale score #4.0) who had completed the 3- year COGIMUS study underwent standardized magnetic resonance imaging, neurological examination, and neuropsychological testing at years 4 and 5. Predictors of cognitive impairment at year 5 were identified using multivariate analysis. Results: Of 331 patients who completed the 3-year COGIMUS study, 265 participated in the 2-year extension study, 201 of whom (75.8%; sc IFN b-1a three times weekly: 44 mg, n = 108; 22 mg, n = 93) completed 5 years\u2019 follow-up. The proportion of patients with cognitive impairment in the study population overall remained stable between baseline (18.0%) and year 5 (22.6%). The proportion of patients with cognitive impairment also remained stable in both treatment groups between baseline and year 5, and between year 3 and year 5. However, a significantly higher proportion of men than women had cognitive impairment at year 5 (26.5% vs 14.4%, p = 0.046). Treatment with the 22 versus 44 mg dose was predictive of cognitive impairment at year 5 (hazard ratio 0.68; 95% confidence interval 0.48\u20130.97). Conclusions: This study suggests that sc IFN b-1a dose-dependently stabilizes or delays cognitive impairment over a 5-year period in most patients with mild RRMS. Women seem to be more protected against developing cognitive impairment, which may indicate greater response to therapy or the inherently better prognosis associated with female sex in MS

Quality of life, depression and fatigue in mildly disabled patients with relapsing-remitting multiple sclerosis receiving subcutaneous interferon beta-1a: 3-year results from the COGIMUS (COGnitive Impairment in MUltiple Sclerosis) study.

BACKGROUND: The precise relationships among quality of life, depression, fatigue and cognitive impairment in multiple sclerosis (MS) are complex and poorly understood. OBJECTIVE: To assess the effects of subcutaneous interferon beta-1a on quality of life, depression and fatigue over 3 years in the COGIMUS study, and to examine the relationship between these outcomes and baseline cognitive status. METHODS: COGIMUS was an observational 3-year trial assessing cognitive function in 459 patients with relapsing-remitting MS treated with subcutaneous interferon beta-1a. RESULTS: In total, 331 patients completed the study (168 received interferon beta-1a, 44 µg subcutaneously three times weekly, and 163 received interferon beta-1a, 22 µg subcutaneously three times weekly). Mean MS Quality of Life-54 (MSQoL-54) composite scores did not change over time. There were no significant differences between groups in MSQoL-54 composite scores when patients were grouped by treatment dose and baseline cognitive status. Mean (standard deviation) Hamilton Depression Rating Scale score decreased from 6.8 (4.9) at baseline to 5.8 (5.9) at year 3. Mean total Fatigue Impact Scale scores were low (<30) at all time points. CONCLUSION: Quality of life, depression and fatigue remained largely stable over 3 years; no effects of treatment dose or baseline cognitive status were found

Changes in magnetic resonance imaging disease measures over 3 years in mildly disabled patients with relapsing-remitting multiple sclerosis receiving interferon β-1a in the COGnitive Impairment in MUltiple Sclerosis (COGIMUS) study

<p>Abstract</p> <p>Background</p> <p>Conventional magnetic resonance imaging (MRI) has improved the diagnosis and monitoring of multiple sclerosis (MS). In clinical trials, MRI has been found to detect treatment effects with greater sensitivity than clinical measures; however, clinical and MRI outcomes tend to correlate poorly.</p> <p>Methods</p> <p>In this observational study, patients (n = 550; 18-50 years; relapsing-remitting MS [Expanded Disability Status Scale score ≤4.0]) receiving interferon (IFN) β-1a therapy (44 or 22 µg subcutaneously [sc] three times weekly [tiw]) underwent standardized MRI, neuropsychological and quality-of-life (QoL) assessments over 3 years. In this <it>post hoc </it>analysis, MRI outcomes and correlations between MRI parameters and clinical and functional outcomes were analysed.</p> <p>Results</p> <p>MRI data over 3 years were available for 164 patients. T2 lesion and T1 gadolinium-enhancing (Gd+) lesion volumes, but not black hole (BH) volumes, decreased significantly from baseline to Year 3 (<it>P </it>< 0.0001). Percentage decreases (baseline to Year 3) were greater with the 44 μg dose than with the 22 μg dose for T2 lesion volume (-10.2% vs -4.5%, <it>P </it>= 0.025) and T1 BH volumes (-7.8% vs +10.3%, <it>P </it>= 0.002). A decrease in T2 lesion volume over 3 years predicted stable QoL over the same time period. Treatment with IFN β-1a, 44 μg sc tiw, predicted an absence of cognitive impairment at Year 3.</p> <p>Conclusion</p> <p>Subcutaneous IFN β-1a significantly decreased MRI measures of disease, with a significant benefit shown for the 44 µg over the 22 µg dose; higher-dose treatment also predicted better cognitive outcomes over 3 years.</p

Postural axial tremor in a patient with cerebellar atrophy

A patient affected by low‐frequency postural tremor of the trunk and limbs is reported. Apart from mild dysarthria and gait ataxia, no other neurological abnormalities were present. Cerebellar atrophy was demonstrated by means of magnetic resonance imaging. The tremor was associated with alternating activity in antagonistic muscles; it was triggered whenever a contraction of lumbar back extensor muscles occurred. Electrical stimulation of the cerebellum did not produce the normal suppression phases of motor responses evoked by a magnetic stimulation of the cerebral cortex. Copyright © 1992 Movement Disorder Societ