Cerebral Glucose Utilization During Sleep in Landau-Kleffner Syndrome: A PET Study

Three right-handed male children (aged 5, 6, and 11 years) with signs, symptoms and/or history of the syndrome of acquired aphasia-epilepsy (Landau-Kleffner syndrome) were studied during drug-induced, electroencephalographically (EEG)-monitored sleep by positron-emission tomography (PET) and the [18F]fluorodeoxyglucose (FDG) method. Our data demonstrate that in Landau-Kleffner syndrome, cerebral glucose utilization is not normal during sleep. The metabolic pattern varied between the children but the metabolic disturbances always predominated over the temporal lobes. They were right-sided, left-sided, or bilateral. In the two first patients, EEG recordings showed continuous spike-and-wave discharges during sleep and a right-greater-than-left asymmetry was observed in temporal areas. In patient 1, the asymmetry was associated with a relative increase of glucose utilization of the right posterior temporal region. In patient 2, the glucose utilization was relatively decreased in the left anterotemporal and left perisylvian regions. In patient 3, the sleep EEG showed no discharge and no significant asymmetry was observed; however, glucose utilization of both temporal lobes was decreased. Lower metabolic rates in subcortical structures than in cortex were also noted in the three children. This metabolic pattern may be related to the maturation of the central nervous system (CNS).     

Landau-Kleffner syndrome: course and correlates with outcome

The presenting characteristics of 18 (11 female, seven male) children with Landau-Kleffner syndrome (LKS) were studied with respect to course and outcome of their condition at a mean length of 67 (SD 46) months' follow-up. All had regression of receptive language (mean age of onset 4 years 9 months) and electrical status epilepticus in sleep (ESES). Length of ESES correlated strongly with length of period between onset of illness and onset of recovery (p<0.006) and also with eventual receptive (p<0.001) and expressive (p<0.007) language. Behaviour during the acute phase was severely affected in nine children and associated with frontal lobe discharges in awake EEGs (p<0.004). Age at onset was not correlated with outcome. All children had impaired short-term memory at follow-up. Three children had language outcome within the normal range. No child with ESES lasting longer than 36 months had normal language outcome. These data lend support for intervention in ending ESES by 36 months using multiple subpial transection (MST) if steroids are ineffective or cause unacceptable side effects.     

Crossed aphasia in a child

Aphasia due to a cortical--subcortical infarct occurred in a right-handed, five year-old boy. Twelve years later, language disturbances were still present.     

Acquired epileptiform aphasia in children (Landau-Kleffner syndrome)

The association of a language disorder with epilepsy is frequent in children, but there is usually no causal relationship. In acquired epileptiform aphasia (AEA), the so-called Landau-Kleffner syndrome, there is increasing evidence that the language disorder is directly caused by epileptic discharges in critical language areas and must be viewed as a special kind of epileptic aphasia. This is based on a review of the published cases of AEA over the last 30 years and on the analogies that can be made between AEA and other epileptic syndromes, mainly benign partial epilepsy with centrotemporal spikes. AEA can start early in development and present as developmental dysphasia. It is only one among other cognitive or behavioral disturbances that can be epileptic manifestations of some particular epileptic syndromes, for example, epilepsy with continuous spike waves during slow sleep, which probably has the same pathophysiology as AEA. AEA must be seen, at least in some cases, as a particular form of resistant epilepsy. AEA is an important model because it suggests that isolated cognitive and behavioral disturbances can be epileptic manifestations in children.     

Acquired Aphasia with Epilepsy–Landau-Kleffner Syndrome

Landau-Kleffner syndrome is characterized by long-lasting acquired aphasia associated with seizures and EEG abnormalities. Three new cases of this rare syndrome are reported from India.     

Acquired aphasia in epilepsy in children with special reference to the Landau-Kleffner syndrome

The problem of acquired aphasia during epilepsy in children is discussed with reference to the correlations between aphasia, epileptic seizures and EEG changes as well as diagnostic difficulties and diagnosis.     

Sign language in childhood epileptic aphasia (Landau-Kleffner syndrome)

Acquired epileptic aphasia (AEA, or Landau-Kleffner syndrome) is a unique condition in which children can lose oral language (OL) comprehension and expression for a prolonged period. These children can benefit from visual forms of language, mainly sign language (SL), but the quality of SL has never been analyzed. The case is reported here of a boy with AEA who lost speech comprehension and expression from 3 years 6 months to 7 years and was educated in SL from the age of 6 years. His SL was evaluated at the age of 13 years and 6 months and compared with a control child with congenital sensorineural deafness. It was found that: (1) our patient achieved the same proficiency in SL as the control child with deafness; (2) SL learning did not compete with, but perhaps even hastened, the recovery of OL. Intact ability to learn a new linguistic code such as SL suggests that higher-order language areas were preserved and received input from a separate visual route, as shown by neuropsychological and functional imaging research in deaf and hearing signers.     

Landau-Kleffner Syndrome: A Pharmacologic Study of Five Cases

Five children with Landau-Kleffner syndrome (epilepsy, acquired aphasia, and continuous spike-wave discharges during sleep), were treated with antiepileptic drugs (AEDs), sleep-modifying drugs, and corticosteroids. The pharmacologic profiles differed from those observed in focal epilepsies, resembling instead those of certain generalized epilepsies, such as West or Lennox-Gastaut syndromes. Phenobarbital (PB), carbamazepine (CBZ), and phenytoin (PHT) were ineffective or worsened the EEG and neuropsychological symptoms, whereas valproate (VPA), ethosuximide (ESM), and benzodiazepines were partially or transiently efficacious. Dextroamphetamine produced a dramatic but transient improvement in waking and sleep EEG in one of two children; aphasia did not change. Corticosteroid treatment resulted in improved speech, suppression of seizures, and normalization of the EEG in three of three children. Our own experience and data from the literature suggest that corticosteroids should be given in high doses as soon as the diagnosis is firmly established and should be continued in maintenance dose for several months or years to avoid escape. Early diagnosis, before mutism or global deterioration develops, appears to be essential for effective therapy with minimal neuropsychological sequelae.     

Correlation between CSWS and aphasia in Landau-Kleffner syndrome: A study of three cases

We report three typical cases of Landau-Kleffner syndrome with varied courses. The very frequent discharges in sleep EEGs, often showing the patterns of CSWS (continuous spike-waves during slow-wave sleep), either typical (spike-wave complex occupying over 85% of slow-wave sleep duration) or atypical (spike-waves occupying less than 85% of slow-wave sleep), were presented in all our cases. The CSWS seems correlated with aphasia in our cases. Since the disappearance of CSWS might be indicative of a lagged improvement in aphasia, we suggest that sufficiently long-term treatment with anticonvulsants and/or corticosteroids is worthwhile, if the EEG is improved significantly by this treatment.     

Low erythrocyte zinc content in acquired aphasia with convulsive disorder (Landau-Kleffner syndrome)

Abnormal zinc metabolism in a 6-year-old male patient with Landau-Kleffner syndrome (acquired aphasia and convulsive disorder) is the subject of our report. We describe a significant decrease of erythrocyte and plasma zinc levels in the patient as compared with normal. Red blood cell zinc content is normally 38.5 +/- 2.7 micrograms/g hemoglobin v 16.5 micrograms/g hemoglobin found in the patient. Plasma zinc level is 94.6 +/- 10.4 micrograms/dL in normal in comparison with 50.4 micrograms/dL in the patient. Normal oral zinc tolerance test performed on the patient precludes altered zinc absorption or increased urinary loss. The possible connection between abnormal zinc metabolism and the pathophysiology of Landau-Kleffner syndrome is discussed.     

Neuropsychological Findings in Rolandic Epilepsy and Landau-Kleffner Syndrome

Summary:  In an attempt to correlate neuropsychological deficits and various neurophysiological aspects of focal epileptic activity in benign childhood epilepsy, we have reviewed the findings of a longitudinal group study of benign childhood epilepsy with centrotemporal spikes (BCECTS) and several case studies of continuous spike-waves during slow sleep syndrome (CSWS). We first distinguish the temporary neuropsychological impairments often observed in the natural history of BCECTS from the more long-lasting and more specific neuropsychological deficits associated with CSWS, of which the Landau-Kleffner syndrome (LKS) is the most studied clinical form. A series of metabolic findings from ¹⁸FDG-PET studies in BCECTS and CSWS children have shown that specific cognitive impairment is related to increased glucose uptake in cortical areas restricted to the associative cortex coincident with the focus of spike-wave discharges. From recent functional neuroimaging data of three patients recovered from LKS, we address the issue of the pathophysiology of cognitive impairment persisting after complete recovery of epilepsy. Finally, we discuss the reliability of the study of mismatch negativity to address the issue of the early effect of interictal discharges in typical and atypical BCECTS on the auditory cortex and the development of speech processing essential to verbal learning.     

The prognostic significance of sound recognition in receptive aphasia

Among 42 aphasics with notable to severe aural verbal comprehension defects in the acute stage of aphasia, 20 with normal sound recognition showed rapid and almost complete recovery of aural comprehension, regardless of how severely aural comprehension was initially impaired. Among 22 receptive aphasics with impaired sound recognition in the acute stage of aphasia, only 32% recovered rapidly; 45% had impairment two years after onset. Results indicated that intact sound recognition predicts rapid and complete recovery of aural comprehension.     

Pseudomigraine with prolonged aphasia in a child with cranial irradiation for medulloblastoma

We report a 12-year-old child with episodes of migraine-like headaches with visual and motor auras a year after the surgical resection and radiation therapy for medulloblastoma The patient presented with an episode of headache, prolonged aphasia, right hemiparesis, status epilepticus, and salt wasting. There was no evidence of a structural lesion. The neurologic deficits resolved over a period of 6 weeks. Because of the progressive deterioration in neurologic deficits, the patient underwent an extensive battery of laboratory tests and multiple neuroimages, all of which were normal. The unusually prolonged neurologic deficit in this patient without demonstrable structural lesions and his eventual complete recovery were most likely caused by ischemia in the left hemisphere secondary to vasospasm. This presentation mimics migraine headache. Evidence suggesting that this represents a long-term complication of treatment of children with central nervous system neoplasia is presented.     

Episodic Memory and Remembering in Adults with Asperger Syndrome

A group of adults with Asperger syndrome and an IQ-matched control group were compared in remember versus know recognition memory. Word frequency was also manipulated. Both groups showed superior recognition for low-frequency compared with high-frequency words, and in both groups this word frequency effect occurred in remembering, not in knowing. Nor did overall recognition differ between the two groups. However, recognition in the Asperger group was associated with less remembering, and more knowing, than in the control group. Since remembering reflects autonoetic consciousness, which is the hallmark of an episodic memory system, these results show that episodic memory is moderately impaired in individuals with Asperger syndrome even when overall recognition performance is not.