Bilateral cerebellar cysts and cerebral white matter lesions with cortical dysgenesis: Expanding the phenotype of LAMB1 gene mutations.

LAMB1 gene analysis should be considered for intellectually disabled patients with cerebellar cysts, white matter signal change, and cortical malformation. Muscular involvement is absent, in contrast to the α-dystroglycanopathy types of congenital muscular dystrophies.

A nationwide survey of pediatric acquired demyelinating syndromes in Japan.

OBJECTIVE: To investigate the clinical and epidemiologic features of pediatric acquired demyelinating syndromes (ADS) of the CNS in Japan. METHODS: We conducted a nationwide survey and collected clinical data on children with ADS aged 15 years or younger, who visited hospitals between 2005 and 2007. RESULTS: Among 977 hospitals enrolled, 723 (74.0%) responded to our inquiries and reported a total of 439 patients as follows: 244 with acute disseminated encephalomyelitis (ADEM), 117 with multiple sclerosis (MS), 14 with neuromyelitis optica (NMO), and 64 with other ADS. We collected and analyzed detailed data from 204 cases, including those with ADEM (66), MS (58), and NMO (10). We observed the following: (1) the estimated annual incidence rate of pediatric ADEM in Japan was 0.40 per 100,000 children (95% confidence interval [CI], 0.34-0.46), with the lowest prevalence in the north; (2) the estimated prevalence rate of MS was 0.69 per 100,000 children (95% CI, 0.58-0.80), with the lowest prevalence in the south; (3) NMO in Japan was rare, with an estimated prevalence of 0.06 per 100,000 children (95% CI, 0.04-0.08); and (4) the sex ratio and mean age at onset varied by ADS type, and (5) male/female ratios correlated with ages at onset in each ADS group. CONCLUSIONS: Our results clarify the characteristic clinical features of pediatric ADS in the Japanese population.

Characterization of SPATA5-related encephalopathy in early childhood.

Mutations in SPATA5 have recently been shown to result in a phenotype of microcephaly, intellectual disability, seizures, and hearing loss in childhood. Our aim in this report is to delineate the SPATA5 syndrome as a clinical entity, including the facial appearance, neurophysiological, and neuroimaging findings. Using whole-exome sequencing and Sanger sequencing, we identified three children with SPATA5 mutations from two families. Two siblings carried compound heterozygous mutations, c.989_991del (p.Thr330del) and c.2130_2133del (p.Glu711Profs*21), and the third child had c.967T>A (p.Phe323Ile) and c.2146G>C (p.Ala716Pro) mutations. The three patients manifested microcephaly, psychomotor retardation, hypotonus or hypertonus, and bilateral hearing loss from early infancy. Common facies were a depressed nasal bridge/ridge, broad eyebrows, and retrognathia. Epileptic spasms or tonic seizures emerged at 6-12 months of age. Interictal electroencephalography showed multifocal spikes and bursts of asynchronous diffuse spike-wave complexes. Augmented amplitudes of visually evoked potentials were detected in two patients. Magnetic resonance imaging revealed hypomyelination, thin corpus callosum, and progressive cerebral atrophy. Blood copper levels were also elevated or close to the upper normal levels in these children. Clinical delineation of the SPATA5-related encephalopathy should improve diagnosis, facilitating further clinical and molecular investigation.

Fulminant sepsis-associated encephalopathy in two children: serial neuroimaging findings and clinical course.

We report on two children with sepsis-associated encephalopathy. They presented with fulminant neurological damage on clinical, neuroimaging, and neurophysiological findings. At onset, both went into deep coma after status epilepticus, resulting in near brain death. Both patients showed diffuse brain edema on CT and severe brain dysfunction on electroencephalography within a day of onset. Brain magnetic resonance (MR) imaging of one patient on day 2 showed restricted diffusion in the basal ganglia and the subcortical white matter of the frontal and occipital lobes. Brain edema aggravated and lasted for a few months despite a variety of treatments. MR imaging in the chronic phase revealed cracking lesions extending to the cerebral white matter, the cerebellum, and the brainstem. MR angiography showed diminished intracranial major arteries. These serial neuroradiological findings suggested severe brain damage resulting from fulminant elevation of intracranial pressure, which mimicked "brain death" or "respirator brain".

Diffusion MRI abnormalities after prolonged febrile seizures with encephalopathy.

BACKGROUND: Patients with encephalopathy heralded by a prolonged seizure as the initial symptom often have abnormal subcortical white matter on diffusion-weighted MRI (DWI). OBJECTIVE: To determine if these patients share other common features. METHODS: Patients with encephalopathy heralded by a prolonged seizure and followed by the identification of abnormal subcortical white matter on MRI were collected retrospectively. Their clinical, laboratory, and radiologic data were reviewed. RESULTS: Seventeen patients were identified, ages 10 months to 4 years. All had a prolonged febrile seizure (longer than 1 hour in 12 patients) as their initial symptom. Subsequent seizures, most often in clusters of complex partial seizures, were seen 4 to 6 days after the initial seizure in 16 patients. Outcome ranged from almost normal to severe mental retardation. MRI performed within 2 days of presentation showed no abnormality. Subcortical white matter lesions were observed on DWI between 3 and 9 days in all 17 patients. T2-weighted images showed linear high intensity of subcortical U fibers in 13 patients. The lesions were predominantly frontal or frontoparietal in location with sparing of the perirolandic region. The diffusion abnormality disappeared between days 9 and 25, and cerebral atrophy was detected later than 2 weeks. Three patients having only frontal lesions had relatively good clinical outcome. CONCLUSIONS: Although the pathophysiologic mechanism remains unknown, these patients seem to have a distinctive encephalopathy syndrome. MRI is helpful in establishing the diagnosis of this encephalopathy.

Biphasic clinical course and early white matter abnormalities may be indicators of neurological sequelae after status epilepticus in children.

Clinical course and serial neuroimaging findings are not fully described in children who have had neurological sequelae following status epilepticus. We found four patients who had neurological sequelae out of 42 children with status epilepticus in 2004. MRI studies were reviewed with specific attention to diffusion-weighted images (DWI) and the apparent diffusion coefficient (ADC). Proinflammatory cytokines, including tumor necrosis factor-alpha and interleukin-6, were measured in the cerebrospinal fluid (CSF) (3 patients). The clinical course showed biphasic; initial status epilepticus and neurological exacerbation along with seizure recurrence four to five days after onset. Within three days after initial status epilepticus, CT (all patients) and MRI (2 patients) did not show any abnormalities. From four to ten days after onset, MRI demonstrated diffuse hyperintensity in the cerebral white matter on DWI and hypointensity on ADC maps in all patients. Diffuse brain atrophy progressed thereafter. Tumor necrosis factor-alpha or interleukin-6 was elevated in all patients. A biphasic clinical course may be a specific feature for neurological sequelae. The preferential white matter involvement on MRI and elevated CSF cytokines indicate that glial dysfunction may play an important role in the pathophysiology of status epilepticus-associated cerebral damage.

Clinical characteristics of acute encephalopathy of obscure origin: a biphasic clinical course is a common feature.

OBJECTIVE: To evaluate the clinical characteristics of acute encephalopathy of obscure origin (AE). STUDY DESIGN: We examined clinical, imaging, and laboratory findings in children with AE. Specific subtypes of AE such as Reye's syndrome (RS), acute necrotizing encephalopathy (ANE), hemorrhagic shock and encephalopathy (HSE), acute encephalitis with refractory, repetitive partial seizures (AERRPS), and hemiconvulsion-hemiplegia syndrome (HH) were diagnosed. Other AE patients were regarded as non-specific subtype. RESULTS: Nineteen patients were identified; specific AEs in 14 and non-specific AE in 5. Patients with RS, ANE, HSE frequently showed neuroimaging abnormalities (9/9) and significant elevation of liver enzymes (7/9) within 2 days after onset. Prognoses were extremely poor; early death in 6 and severe neurological sequelae in 3. Two of the 3 HH patients and 4 of the 5 non-specific AE patients showed biphasic clinical courses (AEBC); consciousness levels transiently improved following initial seizures and were exacerbated at the fourth to sixth days. In AEBC, neuroimaging abnormalities were rarely observed during the acute phase (1/5) but were detectable at clinical exacerbation. They rarely showed severely abnormal elevation in liver enzymes (1/6) and resulted in mild to moderate neurological sequelae (6/6). CONCLUSION: A biphasic clinical course is a common feature in HH and non-specific AE.

Late-onset neuropsychological symptoms in a Japanese patient with megalencephalic leukoencephalopathy with subcortical cysts.

We herein report a Japanese patient with megalencephalic leukoencephalopathy with subcortical cysts (MLC) who developed late-onset neuropsychological symptoms. He demonstrated characteristic clinical features of MLC during childhood, such as slowly progressive megalencepaly, motor impairment with ataxia and spasticity, mild mental retardation, and well-controlled epilepsy. Thereafter, he showed specific neuropsychological symptoms, such as motor and vocal tics, compulsive behavior, perseveration, acquired stuttering, and dystonia since the age of 12. His performance abilities had been unchanged but his verbal abilities had degraded during the past 14 years. Higher cortical dysfunction tests revealed a frontal lobe dysfunction. On repeated brain MRI, a leukoencephalopathy with subcortical cysts remained stationary from infancy. On single photon emission computed tomography (SPECT), a hypoperfusion in the frontal lobe was detected at the age of 3.5 and 17, but the severity of hypoperfusion was also unchanged, respectively. Our results indicate that the frontal lobe dysfunction may be relevant to the late-onset neuropsychological symptoms with MLC.

Risk factors for fatality and neurological sequelae after status epilepticus in children.

Using multivariate regression analysis, we examined risk factors for fatality and neurological sequelae after status epilepticus (SE) in children. Possible risk factors included sex, age at onset, the cause of SE, pyrexia, asthmatic attack during SE, past history of seizure, predisposing neurological abnormality, seizure duration, type of seizure, and medication with theophylline. Consecutive patients with SE, aged 1 month to 18 years, who were referred to Tottori University Hospital from 1984 to 2002 were reviewed. Of the 234 patients enrolled, 45 patients (19.2 %) showed poor outcomes, namely early death in 9 and neurological sequela in 36. Acute neurological insult and progressive neurological disease as the cause of SE were very significantly related to poor outcome (OR = 33.68, p = 0.000). We excluded 21 patients with the etiology of acute neurological insult and progressive neurological disease and then reanalyzed risk factors in the remaining 213 patients. Twenty-nine patients (13.6 %) showed poor outcome, namely early death in 6 and neurological sequela in 23. Seizure duration of more than 2 hours (OR = 12.73, p = 0.000) and moderate to severe asthmatic attack (OR = 31.61, p = 0.010) were associated with poor outcome. These results indicate that long-lasting seizure activity and asthmatic attack can exacerbate SE-associated brain injury.

Vertebral artery dissection in an infant: ultrastructural aberrations in connective tissue components.

We report on a 14-month-old boy who had acute multiple infarcts in the posterior circulation due to an extremely early onset of spontaneous vertebral artery dissection. Despite the absence of clinical signs of connective tissue disorders, an ultrastructural change of collagen fibrils and elastic fibers indicated connective tissue abnormalities. Arterial dissection should be considered as a cause of stroke during infancy.

Frontal N30 of median nerve SSEPs for evaluation of movement disorders with destructive basal ganglia deficits.

This study was performed to show the usefulness of N30 and N20 of median nerve SSEPs for evaluating the pathogenesis of central nervous system movement disorders. The subjects were 14 patients, consisting of 7 patients with an extrapyramidal lesion, 3 patients with suspicion of hypoxic-ischemic cerebral injury before birth period (H-I group), 3 patients with kernicterus during the neonatal period (kernicterus group), and 1 patient having Wilson's disease. Seven patients had spastic hemiplegia. Patients with athetotic CP had the ability to handle an electric wheelchair alone, and those with spastic hemiplegia could walk alone. Thirty control subjects were included in this study for clinical investigation. The characteristic finding of a predominant absence or amplitude reduction of frontal N30 compared with that of parietal N20 (4 and 1, respectively, out of 6 examinations) was obtained in athetotic CP patients of the H-I group. The predominant absence of N30 compared with N20 did not appear in the kernicterus group, hemiplegic patients or a patient with Wilson's disease. Therefore, frontal N30 might sensitively reflect destructive damage in the frontal basal ganglia in children.

[Mitochondrial DNA T to G mutation 8993 in Leigh encephalopathy and organic aciduria].

We report a 10-month-old female infant with Leigh encephalopathy caused by a T to G mutation at nucleotide 8993 of mitochondrial DNA. Initial manifestations were diarrhea and pyrexia, followed by disturbance of consciousness. Blood chemistry showed lactic acidosis, and cranial T2 weighted magnetic resonance imaging demonstrated symmetric high-intensity areas in the basal ganglia, consistent with Leigh encephalopathy. Analysis of urinary organic acids revealed a increase of alpha-ketoglutamate. Derivatives of branched chain amino acids, which accumulate in maple syrup disease, were also increased. Lipoamide dehydrogenase (E3) deficiency was initially suspected; however, normal activity of pyruvate dehydrogenase complex excluded the diagnosis. The organic aciduria disappeared after two weeks. The CNS lesions in our case were observed more prominently in the floor of the bilateral frontal lobes than in the globus pallidus and putamen. In this case, mitochondrial DNA mutation may have caused organic aciduria and the atypical imaging findings.

Somatosensory evoked high-frequency oscillations recorded directly from the human cerebral cortex.

OBJECTIVE: To elucidate the generator sources of high-frequency oscillations of somatosensory evoked potentials (SEPs), we recorded somatosensory evoked high-frequency oscillations directly from the human cerebral cortex. SUBJECTS AND METHODS: Seven patients, 6 with intractable partial epilepsy and one with a brain tumor, were studied. With chronically implanted subdural electrodes, we recorded SEPs to median nerve stimulation in all patients, and also recorded SEPs to lip and posterior tibial nerve stimulation in one. High-frequency oscillations were recorded using a restricted bandpass filter (500-2000 Hz). RESULTS: For the median nerve oscillations, all oscillation potentials were maximum at the electrodes closest to the primary hand sensorimotor area. Most oscillations were distributed similar to or more diffusely than P20/N20. Some later oscillations after the peak of P20 or N20 were present in a very restricted cortical area similar to P25. We investigated the phase change of each oscillation potential around the central sulcus. One-third of the oscillations showed phase reversal around the central sulcus, while later oscillations elicited in a restricted cortical area did not. High-frequency oscillations to posterior tibial nerve and lip stimulation were also maximum in the sensorimotor areas. Most of the lip oscillations showed phase reversal around the central sulcus, but most of the posterior tibial nerve oscillations did not. CONCLUSION: High-frequency oscillations are generated near the primary sensorimotor area. There are at least two different generator mechanisms for the median nerve high-frequency oscillations. We suspect that most oscillations are derived from the terminal segments of thalamocortical radiations or from the primary sensorimotor cortex close to the generator of P20/N20, and some later oscillations from the superficial cortex close to the generator of P25.

Unilateral involuntary movement associated with streptococcal infection: neurophysiological investigation.

Two boys developed rhythmic involuntary movements in the extremities on one side of the body after febrile illness. They also showed behavioral disturbances. In both patients, serum antistreptolysin-O and antistreptokinase titers were elevated in acute illness and decreased a few months later. One patient showed tremorous movement, and the other choreiform movement. In the former, a surface EMG showed short-duration (30 to 60 ms), highly frequent (6 to 8 Hz) and synchronous discharges of multiple muscles, including the antagonists, suggesting myoclonic jerk. In the latter, a surface EMG showed long-duration (0.5 to 1 s), repetitive (about 0.5 Hz) and synchronous or asynchronous discharges of the antagonists, suggesting choreoathetosis. In both patients, giant somatosensory evoked potentials and high-voltage slow EEG activities were observed predominantly in the hemisphere contralateral to the involuntary movement. In the myoclonic patient, long-latency EMG responses were enhanced and cortical potentials preceding the myoclonus were present by jerk-locked back averaging technique. The present data suggest that unilateral rhythmic involuntary movements occur secondary to streptococcal infection. The pathophysiology of the involuntary movements may be associated with sensorimotor cortex hyperexcitability.