Long-term cognitive outcome of hemiconvulsion-hemiplegia-epilepsy syndrome affecting the left cerebral hemisphere

Hemiconvulsion-hemiplegia-epilepsy syndrome in Niger: A retrospective case series

OBJECTIVE

To report the demographic, clinical and paraclinical characteristics as well as the outcomes during follow-up visits of HHE syndrome in Niger.

PATIENTS AND METHODS

It was a retrospective study conducted at the Neurology Outpatient Clinic of the National Hospital of Niamey (Niger) between May 2003 and May 2018.

RESULTS

During the period of study, 882 patients with epilepsy aged 20 years or less were seen in consultation among whom we collected 22 cases of HHE syndrome with a hospital prevalence of 2.5%. They were 14 men and 8 women (sex ratio = 1.75) with a mean age of 3.76 years (range: 1 and 20 years). At the time of diagnosis, 81.8% of patients were aged under 6 years. The antecedent of febrile convulsions in childhood was found in only 31.8% of cases. The mean age of onset of hemiplegia was 1.9 years (range: 9 months and 5 years). The mean age of onset of epileptic seizures was 2.94 years (range: 1 and 8 years). The mean interval between the onset of hemiplegia and onset of epileptic seizures was 9 months (range: 1 month and 4 years). 31.8% of patients had a delay of acquisitions at the time of diagnosis. 95.5% of patients had drug-resistant epilepsy.

CONCLUSION

HHE syndrome is still seen in the countries of Sub-Saharan Africa. The high morbidity and mortality in children with HHE syndrome highlight the need to improve emergency care for febrile clonic seizures in childhood and the early and adequate management of infectious diseases in the child.

Clinical aspects, neuroimaging, and electroencephalography of 35 cases of hemiconvulsion-hemiplegia syndrome

INTRODUCTION

The hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome is a rare consequence of febrile seizures during childhood. It is characterized by the presence of prolonged unilateral clonic seizures occurring during febrile illness in a child less than 4years of age. Then, a flaccid unilateral hemiplegia with variable duration occurs.

OBJECTIVES

The objective of the study was to describe the clinical, electroencephalogram (EEG), and neuroimaging treatment and outcome of series of cases of HHE syndrome followed for 10years in our clinical neurophysiology department of the specialty hospital of Rabat.

PATIENTS AND METHODS

We report a retrospective study of 35 patients followed up for HHE syndrome from January 2005 to December 2015. All patients included in the study met the definition criteria for HHE syndrome.

RESULTS

The age of onset ranged from 1 to 10years. Hemiplegia or spastic hemiparesis of the ipsilateral side to the convulsion was present in all patients. Abnormal brain magnetic resonance imaging (MRI) was found in all patients. All patients developed drug-resistant focal epilepsy during the course of the disease.

CONCLUSIONS

The management of HHE syndrome constitutes a real public health problem in developing countries like Morocco. The neurological morbidity and the severe sequels are of high impact in these young kids. On the one hand, authors highlight the need for improving emergency care of status epilepticus. On the other hand, in our context, the prophylaxis of febrile seizures seems to be the corner stone of the prevention of HHE Syndrome.

An autopsy case of hemiconvulsion-hemiplegia-epilepsy syndrome manifesting as cerebral hemiatrophy in an elderly man

We report an autopsy case of hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome in a 79-year-old man. HHE syndrome usually occurs in children younger than 4 years of age. Although most HHE syndrome patients live into adult life, only a few cases of the syndrome have been reported in the elderly. In our case, cerebral hemiatrophy, left mesial temporal sclerosis and crossed cerebellar atrophy were observed. Because this is the oldest case ever reported, we further investigated age-related neuropathological changes and found an interhemispheric difference in amyloid-β-related neuropathologic changes. There were almost no senile plaques or amyloid-laden vessels in the left hemisphere. As far as we know, this is the first report of age-related neuropathology in a brain manifesting HHE syndrome.

Cyclosporine for acute encephalopathy with biphasic seizures and late reduced diffusion

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common syndrome among the acute encephalopathies, and is associated with a high incidence of neurologic sequelae. This study examined the efficacy of cyclosporine (CsA) for the treatment of AESD.

METHODS

Fourteen children with AESD were recruited and categorized as group A (not receiving CsA) and group B (receiving CsA). Clinical course, laboratory data, magnetic resonance imaging (MRI), and outcome were analyzed retrospectively. We divided the patients into three types according to the distribution of abnormalities on MRI: frontal lobe predominant type, unilateral cerebral hemisphere type, and diffuse type. We used the Pediatric Cerebral Performance Category scale (PCPC) and the Pediatric Overall Performance Category scale (POPC) as prognostic measures.

RESULTS

Of the 14 children, five were boys (age range, 9-32 months). PCPC score was: 1 for seven patients, 2 for three patients, and 3 for four patients. There was no significant difference in PCPC between groups A and B (P = 0.293). POPC score was: 1 for six patients, 2 for five patients, and 3 for three patients. There was a significant difference in POPC between groups A and B when patients with the frontal lobe predominant type were excluded (P = 0.020).

CONCLUSIONS

CsA could improve the neurological prognosis of patients with AESD, except for those with frontal lobe predominant type.

Hemiconvulsion-hemiplegia-epilepsy syndrome. Magnetic resonance findings in a 3-year-old boy

The term 'hemiconvulsion-hemiplegia-epilepsy syndrome' (HHE) was first used by Gastaut et al. to describe the se-quential combination of unilateral or predominantly unilateral clonic seizures (hemiconvulsion), occurring during the first 2 years of life, immediately followed by an ipsilateral flaccid hemiplegia lasting 7 or more days. In the following phase partial epileptic seizures occur. We report a case of HHE syndrome in a 3-year-old boy with partial seizures (hemiconvulsion lasting 15-30 minutes) followed by left hemiplegia and hyporeflexia. Magnetic resonance imaging showed diffuse and high signal hyperintensity of the whole right cerebral hemisphere. Diffusion-weighted images showed a reduction of the apparent diffusion coefficient in the subcortical region. Magnetic resonance arterio-graphy showed a narrow flow signal in the distal territory of the right middle cerebral artery. The authors emphasize the importance of neuroradiological findings in early diagnosis and in the follow-up of HHE syndrome.

Hemiconvulsion-hemiplegia-epilepsy syndrome: current understandings

Hemiconvulsion-Hemiplegia (HH) syndrome is an uncommon consequence of prolonged focal febrile convulsive seizures in infancy and early childhood. It is characterized by the occurrence of prolonged clonic seizures with unilateral predominance occurring in a child and followed by the development of hemiplegia. Neuroradiological studies showed unilateral edematous swelling of the epileptic hemisphere at the time of initial status epilepticus (SE). This acute phase is followed by characteristic cerebral hemiatrophy with subsequent appearance of epilepsy, so called Hemiconvulsion-Hemiplegia-Epilepsy (HHE) syndrome. The etiologies and the underlying mechanisms remain to be understood. Using a review of the literature, we summarized the data of the last 20 years. It appears that idiopathic HH/HHE syndrome is the most common reported form. The basic science data suggest that immature brain is relatively resistant to SE-induced cell injury. Several factors might contribute to the pathogenesis of HH/HHE syndrome: 1. prolonged febrile seizure in which inflammation may worsen the level of cell injury; 2. inflammation and prolonged ictal activity that act on blood-brain-barrier permeability; 3. predisposing factors facilitating prolonged seizure such as genetic factors or focal epileptogenic lesion. However, these factors cannot explain the elective involvement of an entire hemisphere. We draw new hypothesis that may explain the involvement of one hemisphere such as maturation of brain structure such as corpus callosum or genetic factors (CACNA1A gene) that are specifically discussed. An early diagnosis and a better understanding of the underlying mechanisms of HHE are needed to improve the outcome of this condition.

Hemiconvulsion-hemiplegia-epilepsy syndrome in South African children: insights from a retrospective case series

INTRODUCTION

Hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome is a recognized sequel of febrile partial status in children younger than 4 years.

OBJECTIVE

To describe the clinical features, neuroradiology and outcome in 8 South African children with HHE syndrome.

METHOD

A retrospective descriptive study of 8 consecutive cases of HHE syndrome presenting to tertiary hospitals in the Western Cape over a 2 year period.

RESULTS

The median age of onset of convulsive status was 16 months (range: 9-36 months). Gender distribution was equal. The duration of the initial episode of status exceeded 2 h in all children. All children were reported to have been developmentally normal prior to the onset of the first seizure and none previously suffered seizures or had a family history of febrile seizures and epilepsy. In 7 of the 8 cases the initial seizure was not associated with fever or preceding illness. Imaging demonstrated cerebral hemiatrophy in all and additional crossed cerebellar atrophy in 2 children. Moderate to severe intellectual disability ensued in the majority of children. The severity of the intellectual disability correlated with the degree of the motor deficit and occurred irrespective of the cerebral hemisphere involved.

CONCLUSION

In contrast to developed countries, HHE syndrome is still prevalent in South Africa. The neurological morbidity in South African children is significant and highlights the need for improved emergency care of status epilepticus.

Hemiconvulsion-hemiplegia-epilepsy syndrome associated with CACNA1A S218L mutation

Hemiconvulsion-hemiplegia-epilepsy syndrome involves sudden and prolonged unilateral seizures, followed by transient or permanent hemiplegia and epilepsy during infancy or early childhood. Some patients with familial hemiplegic migraine and demonstrating the S218L mutation in CACNA1A experience severe attacks with unilateral cerebral edema after trivial head trauma. We report on a 5-year-old Japanese girl presenting with hemiconvulsion-hemiplegia-epilepsy syndrome after infection with parvovirus B19. Magnetic resonance imaging performed 2 days after admission revealed cerebellar atrophy and marked hyperintensity in the left hemisphere on T(2)-weighted and diffusion-weighted imaging. Magnetic resonance angiography performed 7 days after admission demonstrated obliteration of the left proximal middle cerebral artery in the acute phase. However, this finding was not evident on brain angiography performed 25 hours after magnetic resonance angiography. Genetic analysis of familial hemiplegic migraine revealed a heterozygous S218L mutation in CACNA1A. Taken together, these results suggest that vasospasms of cerebral vascular smooth muscle, with possible cortical spreading depression, may have caused the hemiconvulsions and hemiplegia in the left hemisphere. This case report is the first, to the best of our knowledge, to associate CACNA1A with hemiconvulsion-hemiplegia-epilepsy syndrome and familial hemiplegic migraine, and to suggest that similar pathogenic mechanisms may underlie these two disorders.

Right cerebral hemiatrophy: neurocognitive and electroclinical features

The purpose of this study was to retrospectively evaluate the cognitive and electroclinical characteristics of right cerebral hemiatrophy (Dyke-Davidoff-Masson syndrome [DDMS]). Cognitive assessments with a particular emphasis on visuospatial functions, electroclinical features, and neuroimaging characteristics were analyzed for five patients with a clinically and neuroradiologically confirmed diagnosis of right-sided DDMS. Intelligence tests revealed mental retardation in all but one. Neuropsychological assessments demonstrated consistent impairments in tasks that have a spatial component (spatial processing and orientation discrimination), whereas attention, executive functions and verbal memory domains were variably impaired. Electroclinically, the main seizure types were simple partial motor, complex partial, and secondarily generalized seizures. Interictal EEG delineated lower amplitudes and slow background activity in the affected hemisphere. Overall, the cognitive performance of patients with DDMS encompasses a broad spectrum of impairments affecting multiple domains. Our findings support the concept that dorsal visual pathways responsible for spatial processing may be lateralized to the right hemisphere.