Persistence of suppression-bursts in a patient with Ohtahara syndrome

Early infantile epileptic encephalopathy, or Ohtahara syndrome, is characterized by tonic spasms and a suppression-burst pattern on the electroencephalography (EEG). The EEG demonstrates a suppression-burst pattern during waking and sleeping states that often evolves into hypsarrhythmia and followed later by a diffuse slow spike-wave pattern. In other patients, the EEG evolves into focal spike discharges or multiple independent spike foci. We report a 5-year-old girl with Ohtahara syndrome that persistently demonstrated tonic spasms and suppression-burst on multiple EEGs. Over her lifetime, neither hypsarrhythmia nor diffuse slow spike-wave pattern were seen. This suggests that in Ohtahara syndrome, a suppression-burst pattern can persist over a long period of time.     

Epileptic encephalopathies in early infancy with suppression-burst.

Early infantile epileptic encephalopathy with suppression-burst, or Ohtahara syndrome (OS), and early myoclonic encephalopathy (EME) are epileptic encephalopathies with onset of frequent seizures in the neonatal and early infancy period and with a characteristic EEG pattern, namely, suppression-burst, in which higher-voltage bursts of slow waves mixed with multifocal spikes alternate with isoelectric suppression phase. Their nosologic independence is now widely accepted, although some controversy initially occurred because of their common characteristics such as age of onset, EEG features, seizure intractability, and poor prognosis. Major differences between the two syndromes include (1) tonic spasms in OS versus partial seizures and erratic myoclonias in EME, (2) continuous suppression-burst pattern in both waking and sleeping states in OS versus this EEG pattern almost limited to sleep in EME, and (3) static structural brain damage in OS versus genetic or metabolic disorders in EME. The most important differentiating point is their evolutional pattern with age, which may reflect their pathophysiologic difference. Ohtahara syndrome evolves to West syndrome and further to Lennox-Gastaut syndrome with age, but EME demonstrates no unique evolution; namely, it continues as such for a long time or changes into partial epilepsy or severe epilepsy with multiple independent spike foci.     

A case of infantile epileptic encephalopathy with frequent focal motor status convulsivus: successful treatment with zonisamide]

We reported a 41-day-old girl starting with partial status convulsivus. She had suffered from infantile epileptic encephalopathy manifesting with recurrent focal motor status convulsivus, eventually requiring general anesthesia for the treatment. She had had never myoclonic seizures nor tonic spasms. The examinations including brain MRI scan and metabolic screening tests were all negative. The ictal EEGs showed the onset of the seizures from the left frontal region. Interictal EEG demonstrated multifocal spike discharges as well as discontinuous abnormal EEG pattern resembling suppression-burst during sleep. The seizures were resistant to the multiple antiepileptic drugs, but zonisamide achieved full seizure control as well as improvement of the EEG. Her psychomotor development was severely retarded at 3 years of age.     

An autopsy case of Fahr disease (infantile form)]

A 13-year-old girl with Fahr disease (infantile form) was reported. Her parents were consanguineous. Her elder sister had mental retardation and spasticity of the lower limbs, and died at 23 years of age. The patient suffered from infantile spasms at 3 month. She was bed-ridden, nonverbal, microcephalic and blind. Cranial CT revealed massive calcifications in the basal ganglia, periventricular white matter, dentate nucleus and cerebellar white matter. EEG showed a suppression-burst pattern. At 13 years, she died of pneumonia and hyperammonemia. Microscopic examination of brain showed perivascular non-arteriosclerotic ferro-calcinosis. The periventricular granules are 1-4 mu or 12 mu in diameter. This pathological change was observed only in the central nervous system above midbrain. No calcifications were found in the pituitary and the vessels of pia mater. Also a reduced ornithine transcarbamylase activity was found in the liver, which was probably not related with cerebral calcifications. Infantile form of Fahr disease is rare and may be heterogeneous in etiology. However, clinical manifestations and pathological findings were similar to those in previous reports of Fahr disease in childhood. It is one of the disorders causing infantile spasms.     

West syndrome associated with mosaic Down syndrome

We report a girl with West syndrome associated with mosaic Down syndrome. She had repetitive tonic spasms at 6 months and an electroencephalography (EEG) showed hypsarrhythmia. Her facial appearance was normal and she had no minor anomalies. Her karyotype was mosaic(46,XX/47,XX,+21). Adrenocorticotropin (ACTH) therapy was effective, and her developmental quotient was 76 at 17 months. This report re-emphasize that chromosomal analysis is recommended for epileptic patients with infantile onset when the cause is unclear.     

A case of Kabuki syndrome presenting West syndrome

A 6-month-old girl visited our hospital because of mental retardation, regression, and tonic spasms in cluster. We diagnosed her as West syndrome because of hypsarrhythmia on electroencephalogram (EEG) and tonic spasms in cluster. We also diagnosed her as Kabuki syndrome because of multiple malformations, especially a characteristic peculiar face (resembling a Kabuki actor). She was first administered clonazepam, but this was not effective. Later, she was administered vitamin B6, valproic acid, and zonisamide. Zonisamide was effective, and her tonic spasms were suppressed. Her EEG at 9 months of age showed the disappearance of hypsarrhythmia and sporadic spike and wave complexes on P3, P4, O1, and O2. At 2 years of age, she still showed mental retardation, despite the good control of West syndrome. To the best of our knowledge, Kabuki syndrome presenting West syndrome has been reported in only one previous case. We must pay attention to the occurrence of West syndrome in Kabuki syndrome.     

Age-Dependent Epileptic Encephalopathy: a Longitudinal Study

Abstract: A longitudinal clinico-electroencephalographic study was conducted on 484 cases of age-dependent epileptic encephalopathy; early-infantile epileptic encephalopathy with suppression-burst (Ohtahara) (EIEE), the West and Lennox syndromes. 1) The three types had the same kind of etiologic heterogeneity. 2) An evolutional change with age was noted from EIEE to the West and from the West to the Lennox syndromes, with the change from suppression-burst to hypsarhythmia, and from hypsarhythmia to the diffuse slow spike-waves. 3) The core ictal EEG pattern of tonic spasms was the desynchronization in EIEE and the West syndrome, with the rapid synchronization and recruiting rhythm in the Lennox syndrome. In the same cases, the changes from desynchronization to hypersynchronization were observed with age. These facts suggest that the three syndromes are based on the same pathophysiology, strongly related to the subcortical mechanism, and that their clinico-electrical manifestations are modified by the degree of brain maturation.     

Surgical treatment of a case of early infantile epileptic encephalopathy with suppression-bursts associated with focal cortical dysplasia

We report a surgically treated case of early infantile epileptic encephalopathy (EIEE) with suppression-bursts associated with focal cortical dysplasia. Tonic-clonic seizures followed by a series of spasms occurred about a hundred times a day at a few days of age. Interictal electroencephalogram (EEG) revealed a suppression-burst pattern that was predominant in the left hemisphere. Magnetic resonance imaging (MRI) suggested focal cortical dysplasia in the left prefrontal area. Combination therapies with antiepileptic treatments showed only partial efficacy. The patient underwent lesionectomy at age 4 months, after which he gradually showed psychomotor development and a decrease of spasms to 0-2 series daily. In cases of EIEE with focal cortical dysplasia, surgical treatment may have beneficial effects on both psychomotor development and seizure control.     

Aicardi Syndrome: A Longitudinal Clinical and Electroencephalographic Study

Summary: We report clinical and EEC follow-up of 6 children with Aicardi syndrome. Age at seizure onset was <3 months in 5 patients and 4 months in 1 patient. All patients had spasms, and these continued at time of follow-up in 5 patients. Five patients had seizures other than spasms which disappeared during early infancy. Bilateral independent bursts (BIBs) characteristic of Aicardi syndrome were noted in 4 patients. In 1, BIBs showed suppression-burst patterns. BIBs converted to hypsarrhythmia or multifocal spikes with a tendency to BIBs during sleep. BIBs disappeared completely during both waking and sleeping states between the ages of 3 years 1 month and 4 years 9 months. After BIB disappearance, the EEG of 1 patient showed diffuse slow spike-and-wave complexes most of which appeared asynchronously. At onset, 1 patient had early-infantile epileptic encephalopathy with suppression-burst which evolved initially into West syndrome (WS) and then Lennox-Gastaut syndrome (LGS). The other 3 children also had WS.     

Suppression-burst patterns in intractable epilepsy with focal cortical dysplasia

We report on a patient with early-onset spasms in series and partial seizures associated with focal cortical dysplasia whose EEGs showed suppression-burst patterns during early infancy. These electroclinical characteristics suggested a diagnosis of Ohtahara syndrome, but the EEG findings were atypical because of the lack of suppression-burst patterns during wakefulness. In addition, the patient did not have severe psychomotor retardation. With high-dose pyridoxal phosphate therapy, seizures were suppressed and suppression-burst patterns disappeared at 2 months of age. Focal motor seizures recurred later and they often evolved into epilepsia partialis continua. Patients with early-onset intractable seizures associated with suppression-burst patterns on EEGs have several different etiologies, and these patients should be categorized according to their etiology in addition to their syndromic diagnosis.     

Early-infantile epileptic encephalopathy with suppression-bursts, Ohtahara syndrome; its overview referring to our 16 cases.

Ohtahara syndrome (OS) is characterized by frequent tonic spasms, with or without clustering, of early onset within a few months of life, and a suppression-burst (S-B) pattern in electroencephalography (EEG). Tonic spasms occur in not only waking but also sleeping state in most cases. Partial seizures are observed in about one-third of cases. Brain imagings reveal structural abnormalities including malformations, notably asymmetric lesions in most cases.S-B pattern is persistently observed regardless of circadian cycle. Bursts of 1-3s duration alternate with nearly flat suppression phase of 2-5s at an approximately regular rate; 5-10s of burst-burst interval. Some asymmetry in S-B is noted in about two-thirds of cases. Ictal EEG of tonic spasms shows principally desynchronization with or without initial rapid activity. Tonic spasms appear concomitant with bursts.Characteristic age-dependent evolution from OS to West syndrome (WS) in many cases, and further from WS to Lennox-Gastaut syndrome (LGS) in some, proceed concomitantly with EEG transition from S-B to hypsarrhythmia at around age 3-6 months, and further from hypsarrhythmia to diffuse slow spike-waves at around age 1.Under the inclusive concept of the age-dependent epileptic encephalopathy, OS, WS, and LGS have common characteristics such as age preference, frequent minor generalized seizures, and continuous massive epileptic EEG abnormality. Mutual transition suggests the same pathophysiology among three syndromes and the age factor should be considered as the common denominator responsible for the manifestation of each of their own specific clinico-electrical features. Namely, these syndromes may be the age-specific epileptic reaction to various non-specific exogenous brain insults, acting at the specific developmental stages.     

A case of malignant migrating partial seizures in infancy as a continuum of infantile epileptic encephalopathy

The syndrome of malignant migrating partial seizures in infancy (MMPSI) is characterized by onset before the age of 6 months, nearly continuous electrographic seizures involving multiple independent areas of onset in both hemispheres, and poor developmental outcome. This report presents a case involving a patient with MMPSI, who later developed West syndrome. At the age of 2 months old, he showed multifocal partial seizures, which were refractory to antiepileptic drugs. His electroencephalogram (EEG) revealed characteristic migrating multifocal epileptiform activities and neuroimaging finding was normal. The focal seizures were refractory to antiepileptic drugs and ketogenic diet. When he was 9 months old, epilepic spasms were observed with hypsarrhythmia on EEG. He also showed severe developmental delay. MMPSI may be a continuum of infantile epileptic encephalpathy and could evolve to West syndrome.     

Epidermal nevus syndrome with hemimegalencephaly: a clinical report of a case with acanthosis nigricans-like nevi on the face and neck, hemimegalencephaly, and hemihypertrophy of the body

A 5-year-old boy with the epidermal nevus syndrome and hemimegalencephaly is reported. He had pigmented nevi on the forehead and neck, and hemihypertrophy of the body from the birth. He developed intractable seizures, mental retardation, and right hemiparesis. His seizure pattern changed from early infantile epileptic encephalopathy to infantile spasms at 2 months of age. Electroencephalograms showed a suppression-burst pattern in the neonatal period, subsequently changing to hypsarrhythmia. Computerized tomography of the brain disclosed slight dilatation of the posterior horn of the lateral ventricle at the age of 2 months. Later, hemimegalencephaly with calcification on the left side of the brain was noted. Histological examination of the pigmented nevus on the neck showed it to be an acanthosis nigricans-like lesion. Clinical differences between tuberous sclerosis and epidermal nevus syndrome with hemimegalencephaly are discussed.     

Seizures in Series: Similarities Between Seizures of the West and Lennox-Gastaut Syndromes

We observed seizures resembling infantile spasms in patients with Lennox-Gastaut syndrome (LGS). Infantile spasms, the type of seizures that occurs in patients who have West syndrome, have been well characterized by video-EEG studies and typically occur as a series of sudden generalized flexor or extensor jerks. The seizure types that occur in LGS have not been as clearly delineated. Some patients with West syndrome (WS) in early infancy later develop LGS. Using intensive video-EEG monitoring, we evaluated 14 LGS patients who had seizures that occurred in series. Clinically, the seizures greatly resembled infantile spasms, and the ictal EEG changes were identical to those that occur with infantile spasms. These findings expand the number of features known to be shared by these two syndromes and strengthen the hypothesis that the two syndromes represent age-related manifestations of similar epileptogenic processes.     

Combined treatment with vigabatrin and topiramate in West syndrome

The clinical and electroencephalographic (EEG) response to combined therapy with vigabatrin and topiramate was evaluated in five patients ages 7 to 15 months affected by West syndrome in an open-label trial. Four patients had cryptogenic and one patient had symptomatic (tuberous sclerosis) West syndrome. In cryptogenic patients who failed to respond to pyridoxine, vigabatrin was titrated to 80 to 100 mg/kg. Because control of infantile spasms or an EEG improvement was not obtained with vigabatrin treatment, topiramate was added (3-3.8 mg/kg/day). In all patients, the combined therapy with topiramate and vigabatrin achieved a rapid and complete normalization of infantile spasms, and in three patients with cryptogenic West syndrome, the EEG also became normal. In only one patient, transient anorexia was observed. This drug combination led to rapid neurodevelopmental normalization in cryptogenic patients. The results are promising and justify more trials in larger numbers of children with West syndrome.     

A case with congenital hydrocephaly and west syndrome who recovered from hypsarrhythmia after the resolution of shunt trouble

Hydrocephalus occasionally causes West syndrome, but the mechanism is unknown. We experienced a case with West syndrome and congenital hydrocephaly, in which the EEG findings improved after the resolution of shunt complications. The course of this case implied the pathogenesis of West syndrome associated with congenital hydrocephaly, as well as the origin of the seizures and that of the EEG findings in West syndrome. A 7-month-old girl had congenital hydrocephaly. A prenatal diagnosis was made by ultrasonography, and ventricle-peritoneal shunting was performed 7 days after birth. During the following 7 months several shunt replacements were done because of recurrent shunt complications. Her first series of infantile spasms began at the age of 6 months, and treatment was started under the diagnosis of West syndrome. One month later, her seizures were controlled by pyridoxal phosphate, while the EEG still showed hypsarrythmia. Her shunt was then removed again, because of bacterial meningitis due to shunt infection. The recovery from shunt complication resulted in marked improvement of the hypsarrhythmia. Our experience and previous literature suggest the involvement of cerebral cortex in the occurrence of West syndrome associated with congenital hydrocephaly.     

Clinical and electroencephalographical follow-up study of early myoclonic encephalopathy

We report a clinico-electroencephalographical follow-up study on a male patient with early myoclonic encephalopathy. Frequent massive and fragmentary myoclonic seizures, and myoclonic-clonic seizures were the initial symptoms at the age of 3 days. EEG revealed a suppression-burst pattern at the onset in which burst phases often coincided with myoclonic seizures. Subsequently, non-epileptic erratic myoclonus, various partial seizures and flexor spasms were observed. The partial seizures ceased at around 4 months of age, while the non-epileptic myoclonus and flexor spasms have persisted beyond the age of 6 months. The EEG pattern evolved into atypical hypsarhythmia at two months of age. No specific biochemical or neuroradiological findings were disclosed. His neuropsychiatric development was arrested from the onset. These observations suggest that early myoclonic encephalopathy is an independent epileptic syndrome and that it might be different from early-infantile epileptic encephalopathy described by Ohtahara.     

Familial idiopathic West syndrome

Two families, each with occurrence of West syndrome in two siblings, are presented. Monozygotic twins in family 1 developed infantile spasms at the age of 4 months. Two female siblings in family 2 started to have seizures at the age of 6 months, but 2 years apart. The family history; development prior to West syndrome; clinical, electroencephalographic, and neuroradiologic findings; diagnostic work-up; and treatment are described. The outcome in family 1 (follow-up after 2 years) showed no conspicuous findings on physical and neurologic examination, and psychomotor development appropriate to cognitive, motor, and language developmental age in both twins. In family 2 (follow-up after 3 and 5 years), the older sister only was one standard deviation below mean in intellectual developmental age. Simultaneous occurrence of infantile spasms in both siblings from these two families but with variable clinical expression suggests there is a genetic susceptibility and variable phenotypic expression. Long-term follow-up will demonstrate whether these cases may be classified as "familial idiopathic West syndrome."     

Schinzel-Giedion syndrome: a further cause of West syndrome

Schinzel-Giedion syndrome (SGS) is a rare disorder with a likely autosomal recessive pattern of inheritance which is characterized by several facial dysmorphisms, midface hypoplasia, multiple skeletal anomalies including short and sclerotic skull base, short neck, and post-axial polydactyly. Cardiac and urogenital malformations are also present. Thirty-three cases have been described so far. We report on a boy affected by SGS in whom a long-term EEG follow-up showed a progressive deterioration of the background bioelectric activity ending, at the age of 19 months, with a hypsarrhythmic pattern clinically correlated with severe and refractory infantile spasms. EEG deterioration and neuroradiological findings, which showed progressive brain atrophy, confirm the neurodegenerative nature of SGS. We also re-evaluated all the published cases and found that 33% of patients with SGS experienced neonatal seizures and another 25% developed West syndrome in the following months. The seizures appeared extremely refractory to several anticonvulsive treatments. In conclusion, we believe that SGS should be included among the causes of secondary West syndrome.     

A longitudinal study of clinical and electroencephalographic findings in a female infant with early myoclonic encephalopathy]

We reported a female infant with early myoclonic encephalopathy (EME). She was diagnosed on the basis of clinical and laboratory features including electroencephalographic and magnetic resonance image (MRI) findings. Frequent erratic myoclonic seizures appeared since 28 days after birth and EEG showed a typical suppression-burst pattern. We administered a high-dose pyridoxal phosphate, thyrotropin-releasing hormone analogue (TRH), and then ACTH, but could not control the seizures at all. With seizure types, we observed the change from erratic myoclonus to tonic spasms in series, with concomitant EEG change to hypsarhythmia at the age of 6 months. Cranial MRI revealed delayed myelination in the white matter but no brain malformation. We administered ACTH to her again and succeeded partially in the decrease of the seizure frequency, and significantly in the improvement of EEG findings. It is supposed that the responsiveness to ACTH treatment changed with age as the seizure patterns developed from erratic myoclonus to tonic spasm.