PubMed Health⌕ Search

Biomedical subjects

M M van Dongen

Publications and source records attributed to M M van Dongen.

5 recordsLinked to original sources
PubMed1993

4-Aminopyridine induces functional improvement in multiple sclerosis patients: a neurophysiological study.

This study reports on the neurophysiological measurements that were performed in the context of a randomized, double-blind, placebo-controlled, cross-over study with intravenously administered 4-aminopyridine (4-AP) in 70 patients with definite multiple sclerosis (MS). A beneficial effect of 4-AP was found for both visual evoked response and eye movement registration parameters. This study extends the experimental data obtained on animal nerve fibers, showing that 4-AP can improve impulse conduction in demyelinated nerve, to clinical data which indicate that 4-AP induces an objective improvement in the central nervous system function in MS-patients. It thereby also provides a theoretical basis for clinical efficacy of 4-AP in MS.

4-Aminopyridine↗
PubMed1992

Increased visual impairment after exercise (Uhthoff's phenomenon) in multiple sclerosis: therapeutic possibilities.

The Uhthoff symptom, a transient impairment of visual function after exercise, is demonstrated in 2 multiple sclerosis patients. Following exercise, impairment of visual function, as documented most clearly by the testing of contrast sensitivity, was less obvious after body surface cooling and after treatment with orally administered 4-aminopyridine. It is hypothesized that both treatment modalities improve the nerve conduction safety factor and thereby prevent the occurrence of a conduction block, which is believed to be the mechanism underlying the Uhthoff symptom.

4-Aminopyridine↗
PubMed1991

Sensitivity of eye movement registration and visual evoked potentials in evaluation of therapy in patients with multiple sclerosis.

A major problem in the evaluation of multiple sclerosis (MS) treatment protocols is the lack of an objective and reliable marker of disease activity. In 24 MS patients who were treated with high doses of intravenous methylprednisolone because of an acute relapse or progressive disease the clinical improvement (as measured by the Kurtzke expanded disability status scale) was compared with two paraclinical parameters, i.e. visual evoked potentials (VEP) and the registration of saccadic and smooth pursuit eye movements. After treatment a significant clinical improvement was found in 50% of the patients. The registration of eye movements revealed a significant improvement in 83% of the patients, the VEP in 21%. It is demonstrated that especially the registration of eye movements can have an important application as an objective and sensitive method in the assessment of neurological functions during MS treatment protocols.

Adult↗
PubMed1987

Are eye movement evoked potentials different from pattern reversal evoked potentials?

The averaged lambda wave elicited by saccadic eye movements across a checkerboard pattern has been reported to differ from checkerboard reversal evoked responses, even when the electroencephalographic responses were corrected for the artefact caused by the movement of the dipole moment of the eye itself. Because of these differences it was suggested that the recording of the lambda wave might provide extra information in pathological circumstances. We performed experiments in which the parameters of the pattern (high contrast checkerboard pattern, 20' checks, large field 72 x 72 degrees) shift across the retina were carefully adjusted. For instance, eye movements were made across an integer and odd number of checks in order to mimic the pattern reversal. Furthermore, the timing of the pattern movement in the pattern reversal condition was adjusted so as to simulate the saccadic eye movement. The results seem to suggest that the reported dissimilarities between pattern reversal and eye movement evoked responses can be accounted for by the small differences of the retinal shift in the two conditions.

Evoked Potentials↗