Clinical and diagnostic features of patients with familial multiple sclerosis

Background: Multiple Sclerosis (MS) is a demyelinating CNS disease. Most MS cases are sporadic, however about 20 percent of them are hereditary (Ramagopalan and Sadovnick, 2011). The incidence of familial MS is greater in regions with the highest prevalence of this disease (in North America, Europe) (Ramagopalan and Sadovnick, 2011). It is still unclear whether heredity affects the progression and severity of the disease. The aim of this study is to assess the effect of heredity on the development of multiple sclerosis and on the course of disease by analyzing the results of disability and severity scales, as well as clinical studies, and comparing them with sporadic cases.

Methods: Our study included 104 patients with MS. The study group was comprised of 38 patients with history of first degree relative also affected by MS; the control group consisted of 66 patients with no family history (sporadic case). The anonymous survey included questions about demographic and clinical characteristics. Diagnostic results of magnetic resonance imaging (MRI), oligoclonal bands (OCBs) and visual evoked potentials (VEP) were evaluated retrospectively from medical records. Disability assessment was made according to expanded disability status scale (EDSS). Multiple Sclerosis Severity Score (MSSS) score was calculated using conversion table based on EDSS score and duration of disease in years.

Results: MS patients with first degree relative affected by MS tend to have slower onset of the disease, while control group is more likely to have an acute onset (p < 0.001). The majority of MS with family history considered that their disease is caused by certain factors, while patients in the control group considered that the disease started without any identifiable cause (p < 0.05). Study group more often complained of pyramidal disorders (74% vs. 50%), symptoms related to brainstem (68% vs. 20%) and cortical lesions (47% vs. 20%), headache (37% vs. 9%), back pain (32% vs. 9%) than those in control group, p < 0.05. The degree of disability according to EDSS and MSSS scores were higher in the group of patients with first degree relative with MS (p < 0.05). The number of exacerbations per year was also higher in study group than in the control group (1.4 vs. 0.8; p < 0.05). Patients with a family history have a higher incidence of MRI changes in brainstem (74% vs. 30%) and cerebellum (58% vs. 30%) than the control group (p < 0.01).

Conclusions: MS patients with a family history of MS tend to have slower onset of the disease, while control group is more likely to have an acute onset. Patients with a family history of MS more often complained of brainstem and cortical dysfunction, and pain in head or back. Both the degree of disability according to EDSS and MSSS scores were higher in familial cases. They also have a higher number of exacerbations per year. Patients with a history of first degree relative with MS have a higher incidence of MRI changes in brainstem and cerebellum.