Lamotrigine therapy for paroxysmal dysarthria caused by multiple sclerosis: a case report

Abstract

Paroxysmal dysarthria is a transient dysfunction in the initiation, control or coordination of speech characterized by sudden onset, stereotyped patterns and short duration, occurring many times during the day [1]. The combination of paroxysmal episodes of severe dysarthria and ataxia has rarely been reported in multiple sclerosis (MS) patients and in other neurological diseases such a Beh1et’s and midbrain infarction [1–3]. We report a case of a patient with relapsing–remitting multiple sclerosis (MS–RR) who showed paroxysmal dysarthria as the only manifestation of an acute brainstem relapse. Treatment with carbamazepine was not effective for this patient, but lamotrigine completely suppressed paroxysmal attacks. A 36-year-old woman with a 14-year history of clinically definite multiple sclerosis, free of relapses for about 1 year, presented to our clinic in January 2010 with episodes of severe dysarthria lasting a few seconds, occasionally accompanied by rising burning sensation. Initially, the episodes occurred five or six times a day; later, despite steroid treatment (intravenous methylprednisolone 500 mg/ day for 5 days), the episodes became more frequent, once every 2–5 min. Neurological examination between the attacks showed only residual signs from previous relapses with decreased paresthesia at lower limbs, brisk tendon reflexes and Babinski sign. EEG recording during the attacks showed no paroxysmal discharges (see video). A brain MRI revealed a new right paramedian midbrain lesion below the level of the red nucleus (Fig. 1a) with gadolinium enhancement (Fig 1b). Carbamazepine (orally, 600 mg/day for 10 days) was started with no improvement, while lamotrigine (orally, 100 mg/day) markedly improved paroxysmal dysarthria, resulting in an almost complete suppression of the attacks in about 2 weeks. Because the discontinuation of Lamotrigine led to an immediate recurrence of paroxysmal symptoms, the drug was administered again at the dose of 100 mg/day and the patient remained free from the paroxysmal episodes for a 10-month follow up. A new brain MRI performed 3 months after the beginning of dysarthria showed the disappearance of midbrain lesion enhancement (Fig. 1c). We described one MS patient with episodes of severe dysarthria as the only manifestation of an acute relapse. Brain MRI showed a new right paramedian midbrain lesion below the level of the red nucleus with gadolinium enhancement. In previous reports [1–4], paroxysmal dysarthria, with or without ataxia, has rarely been reported in MS patients and in other neurological diseases such a Beh1et’s and midbrain infarction. All described patients had in common a lower midbrain lesion below the level of the red nucleus, suggesting that an interruption of the cerebellothalamocortical pathway inducing parietal diaschisis and, Electronic supplementary material The online version of this article (doi:10.1007/s00415-011-5901-8) contains supplementary material, which is available to authorized users.