[Hemiconvulsion-hemiplegia syndrome: two case reports with findings from magnetic resonance imaging of the brain in diffusion-weighted sequences].

INTRODUCTION

Hemiconvulsion-hemiplegia (HH) syndrome is characterised by prolonged hemiclonic seizures followed by, very often permanent, hemiplegia. We report the cases of two patients with HH syndrome; in addition, the paper also includes a discussion of the value of neuroimaging in its diagnosis, including the use of magnetic resonance imaging (MRI) of the brain in diffusion-weighted sequences, and its clinical-radiological progression.

CASE REPORTS

Case 1: a 16-month-old female who was admitted to hospital owing to right-side hemiclonic seizures, with a febrile condition, that lasted at least 30 minutes, and persistent hemiparesis on the right-hand side of the body. Results of an initial computerised tomography (CT) brain scan were normal. Brain MRI at 3 days: T2 weighted sequences were normal; diffusion-weighted sequences showed lowered diffusion in the temporoparietooccipital region in the left hemisphere. Brain CT scan at 6 months: hemiatrophy on the left-hand side of the brain. Paresis of the right hand continues at the age of 4 years and 8 months; no further seizures have occurred and the patient's psychic development is normal. Case 2: a female aged 2 years and 6 months who was admitted to the Paediatric Intensive Care Unit owing to right-side hemiclonic seizures, with a feverish condition, lasting between 35-40 minutes, with persistent hemiplegia on the right-hand side of the body. The patient had a history of psychomotor retardation secondary to chromosome pathology; findings from a brain CT scan were normal. CT scan at 48 hours after the episode: edema in the left hemisphere of the brain. Brain MRI at 7 days following hospital admission: extensive involvement of the left hemisphere of the brain could be seen in T2 weighted sequences and in diffusion-weighted sequences. CT scan at 3 months: hemiatrophy on the left-hand side of the brain. Hemiparesis persists at the age of 5 years and 4 months; the patient has had no further seizures and attends specialised schooling.

CONCLUSION

Although rare in our environment, HH syndrome can be seen in the context of hemiclonic febrile conditions. MRI of the brain in diffusion-weighted sequences may be the only means of proving the initial brain lesion.