Our objective was to assess the clinical characteristics and present follow-up data and medium-term outcome for 6 Tunisian patients with Baló concentric sclerosis (BCS).

Baló concentric sclerosis is a rare demyelinating disease. It is a rare form of multiple sclerosis (MS). The prognosis of patients who develop symptoms of a Baló lesion varies. It is usually considered to be poor or even fatal. Benign evolution is more rare.

Six patients from Tunisia diagnosed with BCS during first clinical event were studied retrospectively (median time follow up was 5.9  years). Demographic, clinical and radiological data were analysed. Clinical medium-term outcome was assessed with EDSS score.

Mean age at onset was 36. All patients developed relapsing-remitting MS. Motor symptoms were the most common mode of onset ( five patients ). Two patients had focal seizures which were inaugural in one case, requiring the use of anti-epileptic drugs. CSF examination was normal in five cases including immunoglobulin G (IgG) index and electrophoresis to detect oligoclonal bands except one case were we noticed hyperproteinorachia at 0,91g/l. All patients recieved 3 to 5 days of IV methylprednisolone (IVMP) within the first relapse relayed with Bolus therapy with methylprednisolone (1 g), given monthly for one year. Only two patients were treated with an interferon. EDSS score at the end of follow up was zero for three patients, one for two patients and two for the last patient.

Our study shows that patients who develop symptomatic Baló lesions can make a substantial or complete recovery.  Our BCS patients seems not to differ from the classical relapsing-remitting MS or even to have better outcome. Despite improved understanding of BCS, there are still several areas of uncertainty such as the prognosis of this form of MS. An international collaborative study is needed to reach conclusions about various aspects of this disease.