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.