Lymphocyte subtypes in relapsing-remitting multiple sclerosis patients treated with dimethyl fumarate

BACKGROUND

Recent data suggest that lymphopenia is more prevalent than reported in relapsing-remitting multiple sclerosis (RRMS) patients taking dimethyl fumarate (DMF).

OBJECTIVE

The objective of this study was to investigate the effect of DMF on lymphocyte subtypes in RRMS patients with and without lymphopenia.

METHOD

A retrospective study compared lymphocyte subtypes in DMF-treated RRMS patients with low (G1, n = 35) and normal lymphocyte counts (G2, n = 24).

RESULTS

Fifty-nine patients were identified, with mean age 49, 71.2% females, and average DMF duration 20 months. Age, sex, baseline white blood count, disease and treatment durations were similar between groups. Prior interferon therapy and baseline lower normal lymphocyte counts were more frequent in G1. Mean lymphocyte counts were 0.8 ± 0.2 × 10⁹/L in G1 and 1.6 ± 0.3 × 10⁹/L in G2. CD3⁺, CD4⁺, and CD8⁺ T cell mean counts were lower (p < 0.0001), while CD4/CD8 ratio higher (p = 0.03) in G1 than G2. Mean CD19 ⁺B cell counts were normal; however, values were lower in G1 (p = 0.04). After adjusting for confounders, significantly positive correlations were noted between lymphocyte counts and CD3 ⁺, CD4⁺, CD8⁺ T, and B cell counts. Negative correlation was observed between lymphocyte counts and CD4/CD8 ratio driven by low CD8⁺ T cell counts.

CONCLUSION

DMF treatment predominantly impacts T cells, in particular CD8⁺ subtype. This finding may have implications in this population's immunocompetence.

Hemineglect and seizures in Binswanger's disease: clinical-pathological report

The range of clinical effects from ischaemic damage to white matter in Binswanger's disease has not been fully characterised. Although focal deficits and seizures occur frequently, superficial infarcts often coexist, making the cause of these symptoms unclear. The case of a 69 year old woman is described who presented with acute left sided weakness and hemispatial neglect, followed a year later by electrographically documented seizures originating from the right hemisphere. Interim examinations showed bilateral pyramidal signs and mild intellectual decline. Serial CT and MRI studies showed bilateral diffuse ischaemic lesions of the cerebral white matter and old left sided lacunar infarcts but no evidence of acute infarction. Post-mortem examination showed gliosis and demyelination of the deep white matter which spared the subcortical arcuate fibres; this is consistent with Binswanger's disease. The neocortex was normal. This case and previous reports indicate that focal symptoms typically referable to the grey matter, including hemineglect and seizures, may occur as a manifestation of subcortical ischaemic injury to white matter in Binswanger's disease.

Paroxysmal kinesigenic dystonic choreoathetosis associated with a thalamic infarct

We describe a patient with the development of paroxysmal kinesigenic dystonic choreoathetosis (PKDC) after a thalamic infarct. PKDC consists of brief episodes of dystonia or choreoathetosis triggered by movement. PKDC improves with anticonvulsants, and in some cases, with L-Dopa or anticholinergics. We review PKDC, and relate its salient features to idiopathic and secondary torsion dystonia. We postulate a similar underlying pathophysiology.