儿童交替性偏瘫的临床特征和脑血流灌注改变

目的探讨儿童交替性偏瘫的临床特点及脑血流改变。方法对近23年收治的11例患儿的临床资料进行分析,并对6例患儿应用单光子发射计算机断层扫描进行脑血流灌注观察,其中4例在发作间期,1例在发作期,1例在发作间期和发作期均进行测定,以兴趣区法作半定量分析。结果11例患儿的临床特征一般为18个月内起病,表现为频繁发作的交替性偏瘫、短暂的眼球震颤、肌张力异常、舞蹈徐动样动作,常伴自主神经功能紊乱和认知功能减退;睡眠可缓解上述症状。2次发作期单光子发射计算机断层扫描均示偏瘫对侧脑血流减少,5次发作间期均正常。结论本病的主要临床特征为一般18个月内起病的反复发作的交替性偏瘫,伴锥体外系症状及智能障碍;发作期偏瘫对侧脑血流减少。     

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Several reports have indicated that cortical resection is effective in alleviating intractable epilepsy in children with tuberous sclerosis complex (TSC). Because of the multitude of cortical lesions, however, identifying the epileptogenic tuber(s) is difficult and often requires invaise intracranial electroencephalographic (EEG) monitoring. As increased concentrations of serotonin and serotonin-immunoreactive processes have been reported in resected human epileptic cortex, we used α-[¹¹C]methyl-L-tryptophan ([¹¹C]AMT) position emission tomography (PET) to test the hypothesis that serotonin synthesis is increased interictally in epileptogenic tubers in patients with TSC. Nine children with TSC and epilepsy, aged 1 to 9 years (mean, 4 years 1 month), were studied. All children underwent scalp video-EEG monitoring, PET scans of glucose metabolism and serotonin synthesis, and EEG monitoring during both PET studies. [¹¹C]AMT scans were coregistred with magnetic resonance imaging and with glucose metabolism scans. Whereas glucose metabolism PET showed multifocal cortical hypometabolism corresponding to the locations of tubers in all 9 children, [¹¹C]AMT uptake was increased in one tuber (n = 3), two tubers (n = 3), three tubers (n = 1), and four tubers (n = 1) in 8 of the 9 children. All other tubers showed decreased [¹¹C]AMT uptake. Ictal EEG data available in 8 children showed seizure onset corresponding to foci of increased [¹¹C]AMT uptake in 4 children (including 2 with intracranial EEG recordings). In 2 children, ictal EEG was nonlocalizing, and in 1 child there was discordance between the region of increased [¹¹C]AMT uptake and the region of ictal onset on EEG. The only child whose [¹¹C]AMT scan showed to no regions of increased uptake had a left frontal seizure focus on EEG; however, at the time of his [¹¹C]AMT PET scan, his seizures had come under control. [¹¹C]AMT PET may be a powerful tool in differentiating between epileptogenic and nonepileptogenic tubers in patients with TSC.     

Single photon emission computed tomography findings in a case of alternating hemiplegia of childhood in relation to migraine

Single photon emission computed tomography (SPECT) was performed 3 times during attacks and performed 4 times during postictal periods on a case of alternating hemiplegia of childhood. Hyperperfusion of the corresponding hemisphere to hemiparesis was suggested by asymmetric increase RI uptake during the ictal scans, whereas interictal scans showed symmetric topography of cerebral blood flow. Manifestations except hemiplegia included loss of consciousness and vomiting. These manifestations and ictal SPECT findings are the same evidence as hemiplegic migraine. It suggests that these two disorders have a similar pathophysiology. There are two interesting findings regarding this patient. The first finding is magnetic resonance imaging showed progressive cerebellar atrophy. Second finding is interictal SPECT showed a progressive decrease of cerebral perfusion, especially in cerebellar hemispheres. These two findings suggest alternating hemiplegia of childhood may be a chronic progressive disorder.     

Developmental changes in brain serotonin synthesis capacity in autistic and nonautistic children

Serotonin content, serotonin uptake sites, and serotonin receptor binding measured in animal studies are all higher in the developing brain, compared with adult values, and decline before puberty. Furthermore, a disruption of synaptic connectivity in sensory cortical regions can result from experimental increase or decrease of brain serotonin before puberty. The purpose of the present study was to determine whether brain serotonin synthesis capacity is higher in children than in adults and whether there are differences in serotonin synthesis capacity between autistic and nonautistic children. Serotonin synthesis capacity was measured in autistic and nonautistic children at different ages, using alpha[11C]methyl-L-tryptophan and positron emission tomography. Global brain values for serotonin synthesis capacity (K complex) were obtained for autistic children (n = 30), their nonautistic siblings (n = 8), and epileptic children without autism (n = 16). K-complex values were plotted according to age and fitted to linear and five-parameter functions, to determine developmental changes and differences in serotonin synthesis between groups. For nonautistic children, serotonin synthesis capacity was more than 200% of adult values until the age of 5 years and then declined toward adult values. Serotonin synthesis capacity values declined at an earlier age in girls than in boys. In autistic children, serotonin synthesis capacity increased gradually between the ages of 2 years and 15 years to values 1.5 times adult normal values and showed no sex difference. Significant differences were detected between the autistic and epileptic groups and between the autistic and sibling groups for the change with age in the serotonin synthesis capacity. These data suggest that humans undergo a period of high brain serotonin synthesis capacity during childhood, and that this developmental process is disrupted in autistic children.     

Increased brain serotonin synthesis in migraine.

OBJECTIVE: To measure brain serotonin synthesis with PET using the tracer alpha-[11C]methyl-L-tryptophan in migraine patients. BACKGROUND: Although the cause of migraine remains poorly understood, there is considerable evidence to support a role of the neurotransmitter serotonin in the pathophysiology of migraine. METHODS: We studied 11 women (aged 33+/-7.7 years) with a diagnosis of migraine according to International Headache Society criteria and 8 healthy women (aged 29+/-9.2 years). Five patients were studied before and after chronic treatment with propranolol or nadolol. RESULTS: Serotonin synthesis capacity (K-complex) values in migraine patients were higher than those measured in controls throughout the brain (p = 0.016); mean K-complex for whole brain was 0.0077 + 0.0020 mL/g/min in patients with migraine and 0.0054+/-0.0003 mL/g/min in controls. The regional pattern did not differ between the two groups. However, the K-complex for whole brain in the subgroup of migraine patients with aura (n = 3) did not differ from that of the control group (p = 0.32). In the five patients studied twice (before and after treatment), we found a trend of increased whole-brain K-complex after drug treatment (p = 0.06). CONCLUSIONS: Our findings indicating increased brain serotonin synthesis capacity in migraine patients are consistent with previous reports of systemic alteration of serotonin metabolism in patients without aura. Our results also suggest that the mechanism of action of beta-adrenergic antagonists for migraine prophylaxis may involve regulation of serotonin synthesis.     

Single-photon Emission Computed Tomography Investigations of Alternating Hemiplegia of Childhood

Alterations in regional cerebral blood-flow, a s determined by single-photon emission computed tomography (SPECT) using technetium [*Tc] hexamethyl propylenamine oxime, were studied in two children presenting with alternating hemiplegia of childhood. Both experienced hemiplegic episodes several times per month, despite marked improvement on flunarizine therapy. SPECT images of both patients revealed focal areas of decreased uptake of the radiotracer, representing impaired regional cerebral blood-flow during, as well as between, seizures. The interictal finding of localized areas of reduced tracer uptake suggest that long-lasting hypoperfusion could be the patho-physiological, mechanism by which the slowly resolving hemiplegia, and ultimately the permanent multifocal neurological deficits, are produced.     

Localizing value of alpha-methyl-L-tryptophan PET in intractable epilepsy of neocortical origin.

BACKGROUND: [(11)C] alpha-methyl-L-tryptophan (alpha-MTrp) has been developed as a tracer for the study of the synthesis of serotonin in the brain with PET. However, it has been shown that in pathologic conditions the tracer may reflect the activation of kynurenine metabolism. Increased levels of serotonin and quinolinic acid have been described in resected epileptogenic cortex, raising the possibility that alpha-MTrp can localize seizure foci in patients with intractable partial epilepsy. The authors assessed the uptake of alpha-MTrp in 18 patients (11 men, mean +/- SD age 27.1 +/- 10.1 years, range 13 to 54) with intractable partial epilepsy to correlate the PET findings with the epileptogenic area defined by electroclinical and neuroimaging data. METHOD: Seven patients with cortical dysplasia (CD) and 11 with partial epilepsy in which conventional MRI and fluorine-18-deoxyglucose ((18)FDG)-PET studies failed to detect any abnormality were studied. All underwent scalp EEG monitoring during the PET scan to exclude ictal events and estimate the interictal epileptic activity. RESULTS: In seven patients (39%; CD four and cryptogenic partial epilepsy three), PET showed focal increased uptake of alpha-MTrp corresponding to the epileptogenic area. alpha-MTrp uptake in the epileptic focus correlated with the frequency of interictal spikes (r = 0.7, p < 0.05). CONCLUSIONS: alpha-MTrp-PET may be of value in the localization of the epileptogenic area not only in patients with visible dysplastic lesions, but also in those with cryptogenic partial epilepsy.     

Functional Neuroimaging with Positron Emission Tomography

Summary: Epilepsy research using positron emission tomography (PET) has provided considerable new information about ictal and interictal dysfunctions in human epilepsy. Neuroreceptor mapping with PET ligands has revealed altered central benzodiazepine receptor and opiate receptor densities in partial epilepsies interictally, and regional increases in endogenous opioid peptide concentrations during absence seizures. Imaging of perfusion and glucose metabolism during cognitive processing has shown interictal abnormalities of regional activation in partial and generalized epilepsies. The diagnostically robust patterns of interictal glucose hypometabolism are not adequately explained by macrostructural and microstructural alterations in temporal lobe epilepsy. Current investigations of the pathophysiology of interictal hypometabolism must address ultrastructural and neurochemical factors. Clinical PET in pre-surgical evaluation of medically refractory epilepsies remains an active area of research, but remarkably little antiepileptic drug research has exploited PET techniques.     

Alternating hemiplegia of childhood: Studies of regional cerebral blood flow using 99mTc-hexamethylpropylene amine oxime single-photon emission computed tomography

Alternating hemiplegia of childhood is a rare disorder of unknown cause associated with progressive neurological deterioration. We report the results of regional cerebral blood flow studies using ^99mTc-hexamethylpropylene amine oxime single-photon emission computed tomography in 3 patients. These studies were performed during the hemiplegic attacks (n = 6) and during the symptom-free periods (n = 2). Six single-photon emission computed tomographic studies performed during hemiplegic attacks consistently showed relative hyperperfusion of the contralateral cerebral hemisphere. Two single-photon emission computed tomographic studies performed during the asymptomatic phase showed normal and symmetrical cerebral perfusion. This is the first definite demonstration of unilateral increase of cerebral blood flow in alternating hemiplegia. These findings support the possibility of a relationship between the cause of alternating hemiplegia and migraine.     

Age-related gender differences in reporting ictal fear: analysis of case histories and review of the literature

To determine if there are age or gender-related differences in reporting fear as a symptom of epileptic seizure, all clinical charts of patients evaluated at the "C. Munari - Epilepsy Surgery Center" of Milan from 1990 to June 2005 were analyzed, looking for patients with ictal fear. Among the 2,530 clinical charts examined (1,330 male and 1,200 female), 265 patients were found with ictal fear (100 men, 165 women). The gender difference in reporting ictal fear was not so marked in the pediatric age group (98 girls, 74 boys), whereas in adult patients the difference was significant (158 women, 83 men). Interestingly, more men than women (14:3) had ictal fear during childhood that disappeared during adulthood. The literature review confirmed that ictal fear is significantly more common in women, though there is no gender difference in the pediatric age group.     

Ictal brain imaging in presurgical evaluation of patients with medically intractable complex partial seizures

At the Indiana University Medical Center, 99 patients with medically intractable complex partial seizures (MI-CPS) had presurgical evaluation with subsequent anterior temporal lobectomy. The majority of the patients had single photon emission tomography (SPECT) performed interictally as well as during an actual epileptic seizure (ictal scan). Decreased regional cerebral perfusion (rCP) was seen in 54/94 (57%) of the interictal scans corresponding to the eventual site of the surgery. However, ictal scans provided a higher yield; increased rCP in the temporal lobe during an actual seizure was observed in 60/82 (73%) concordant to the side of surgery. SPECT is a useful, noninvasive method of localizing the epilepti-form focus in patients with MI-CPS considered for resective surgery. Both interictal and ictal SPECT need to be performed; combined interictal hypo-perfusion and ictal hyperperfusion in the same focal area are unique to epileptogenic lesions. Ictal SPECT studies can be performed in the majority of patients during the period of continuous video/EEG monitoring with only a little additional effort. Combining the results of functional brain imaging (interictal and ictal SPECT, PET) with clinical semiology of seizures, surface and sphenoidal EEG, magnetic resonance imaging and other non-invasive tests, anterior temporal lobectomy can be recommended in approximately two-thirds of the patients without resorting to potentially dangerous intracranial EEG monitoring.     

Benzodiazepine-GABAA Receptor Binding During Absence Seizures

Summary: The role of benzodiazepine (BZD)-γ-aminobutyric acid, (GABA) receptors in the pathogenesis of absence seizures is uncertain. In this study, we examined the effect of absence seizures on the binding of flumazenil to the BZD binding site of the GABA, receptor. Five patients with idiopathic generalized epilepsy (IGE) were studied at rest and during absence seizures with [¹¹C]flumazenil and positron emission tomography (PET). Normalized regional cerebral time-activity curves from the resting and ictal scans were compared with each other and with computed simulations showing the effects of changes in cerebral blood flow (CBF) and [¹¹Clfluma-zenil binding. No evidence was found for a change in [¹¹C]flumazenil binding with absence seizures. This result, together with those of a recent study showing no abnormality of [¹¹C]flumazenil binding interictally in patients with childhood and juvenile absence epilepsy (JAE) does not support a primary role for the BZD binding site of the GABA, receptor in the pathogenesis of absence seizures.     

Alternating hemiplegia of childhood and a pathogenic variant of ATP1A3: a case report and pathophysiological considerations

We describe a case of a child suffering from alternating hemiplegia with a heterozygous p. E815K pathogenic variant of ATP1A3. The patient started to present abnormal eye movements in the first days of life, followed by the appearance at 2 months of dystonic episodes, and later on, by recurrent episodes of alternating hemiplegia more often on the right side. A severe epilepsy started at the age of 2 years with episodes of status epilepticus since the onset which frequently recurred, requiring admission to the intensive care unit. MRI showed bilateral mesial temporal sclerosis and a left‐sided ischaemic lesion. Interictal EEG showed bilateral abnormalities, whereas postictal EEG after status epilepticus showed overt slowing on the left side, suggesting a predominant involvement of ictal activity of the left hemisphere. We hypothesize that in our patient, the left hemisphere might have been more prominently affected by the pathogenetic abnormalities underlying alternating hemiplegia of childhood, rendering it more prone to early ischaemic lesions and recurrent unilateral status epilepticus. We speculate whether alternating hemiplegia of childhood shares some common pathophysiological mechanisms with familial hemiplegic migraine that may be associated with a pathogenic variant of ATP1A2.     

alpha-[11C]-Methyl-L-tryptophan PET identifies the epileptogenic tuber and correlates with interictal spike frequency

Epilepsy surgery has been successfully performed in patients with tuberous sclerosis complex (TSC) and seizures arising from a restricted epileptogenic area. The outcome of cortical excision depends on accurate pre-surgical identification of the epileptogenic tuber. [11C] alpha-methyl-L-tryptophan (alpha-MTrp) was originally developed to measure serotonin synthesis in vivo with positron emission tomography (PET). However in pathologic conditions its uptake may also depend on the synthesis of quinolinic or kynurenic acid via the kynurenine pathway. Increased levels of serotonin and quinolinic acid have been observed in epileptogenic lesions, raising the possibility that alpha-MTrp PET may localize the epileptogenic area. The aim of this study was to correlate alpha-MTrp PET uptake with the localization of the epileptogenic area and with interictal spike frequency in patients with TSC. alpha-MTrp uptake was measured in 8 patients (2 males, mean age 29.6+/-14.9 years, range 3-50 years) with intractable partial epilepsy due to TSC. All patients underwent scalp EEG monitoring during the PET scan. In four (50%), increased uptake of alpha-MTrp occurred in the epileptogenic area alone. Two (25%) patients showed multifocal abnormalities and the remaining two (25%) did not show focal changes. PET localization was mostly seen in patients with frequent interictal abnormalities on the EEG. Furthermore, there was a significant correlation between alpha-MTrp uptake and the frequency of interictal spikes (r=0.6; P<0.05). alpha-MTrp PET is a promising diagnostic tool in the localization of the epileptogenic area in patients with TSC.     

Human brain serotonin synthesis capacity measured in vivo with α-[C-11]methyl-L-tryptophan

Local cerebral serotonin synthesis capacity was measured with α-[C-11]methyl-L-tryptophan ([C-11]AMT) in normal adult human brain (n = 10; five males, five females; age range, 18–38 years, mean 28.3 years) by using positron emission tomography (PET). [C-11]AMT is an analog of tryptophan, the precursor for serotonin synthesis, and is converted to α-[C-11]methyl-serotonin ([C-11]AM-5HT), which is trapped in serotonergic neurons because [C-11]AM-5HT is not degraded by monoamine oxidase. Kinetic analysis of [C-11] activity in brain after injection of [C-11]AMT confirmed the presence of a compartment with unidirectional uptake that represented approximately 40% of the activity in the brain at 50 min after tracer administration. The undirectional rate constant K, which represents the uptake of [C-11]AMT from the plasma to brain tissue followed by the synthesis and physiologic trapping of [C-11]AM-5HT, was calculated using the Patlak graphic approach on a pixel-by-pixel basis, thus creating parametric images. The rank order of K values for different brain regions corresponded well to the regional concentrations of serotonin in human brain (P < .0001). High serotonin synthesis capacity values were measured in putamen, caudate, thalamus, and hippocampus. Among cortical regions, the highest values were measured in the rectal gyrus of the inferior frontal lobe, followed by transverse temporal gyrus; anterior and posterior cingulate gyrus; middle, superior, and inferior temporal gyri; parietal cortex; occipital cortex, in descending order. Values in women were 10–20% higher (P < .05, MANOVA) throughout the brain than those measured in men. Differences in the serotonin synthesis capacity between men and women measured in this study may reflect gender differences of importance to both normal and pathologic behavior. This study demonstrates the suitability of [C-11]AMT as a tracer for PET scanning of serotonin synthesis capacity in human brain and provides normal adult values for future comparison with patient groups. Synapse 28:33–43, 1998. © 1998 Wiley-Liss, Inc.     

Benign nocturnal alternating hemiplegia of childhood: A new case with unusual findings

It has been described a neuro developmental disorder labelled “Benign nocturnal alternating hemiplegia of childhood” (BNAHC) characterized by recurrent attacks of nocturnal hemiplegia without progression to neurological or intellectual impairment. We report a female patient who at 11 months revealed a motionless left arm, unusual crying without impairment of consciousness and obvious precipitating factors. The attacks occur during sleep in the early morning with lack of ictal and interictal electroencephalographic abnormalities, progressive neurological deficit, and cognitive impairment. Unlike previous reports of BNAHC our patient come from a family with a history of both migraine, hemiplegic migraine, and sleep disorders. Our study remarks on the typical features described in previous studies and stresses the uncommon aspects that could help to identify the disorder which is likely to have been underestimated. Despite some clinical similarities between BNAHC and familiar hemiplegic migraine and alternating hemiplegia of childhood, the genetic analyses of our patient did not reveal genetic mutations found in both disorders.     

Benign nocturnal alternating hemiplegia of childhood: six patients and long-term follow-up.

Benign familial nocturnal alternating hemiplegia of childhood refers to recurrent attacks of hemiplegia arising from sleep, described in young children without neurologic or mental impairment. It is probably migraine related. The authors report two unrelated patients with nocturnal attacks starting at 22 and 31 months, followed by daytime episodes in one. The authors confirm the benign course of this disorder. It is distinct from the classic malignant form of alternating hemiplegia of childhood.     

Ictal 99mTc-HMPAO SPECT in alternating hemiplegia

99mTc-hexamethylpropylenamine oxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) was performed in a patient with alternating hemiplegia during 2 episodes of the disease. The regional cerebral blood flow patterns correlated with the clinical manifestations during both episodes. Hyperperfusion of the contralateral hemisphere was suggested by asymmetric 99mTc-HMPAO uptake, whereas symmetric 123I-N-isopropyl-p-iodoamphetamine uptake was detected during the interictal period. The results suggested that alternating hemiplegia in infants represents an atypical manifestation of epilepsy, despite the lack of paroxysmal electroencephalographic abnormalities during the episodes. 99mTc-HMPAO SPECT appears to be a useful method for detecting transient regional cerebral blood flow alterations during paroxysmal events because the tracer is rapidly available for emergencies and retains a fixed distribution for 5-8 hours, sufficient time to allow for SPECT acquisition.     

Significance of abnormalities in developmental trajectory and asymmetry of cortical serotonin synthesis in autism

The role of serotonin in prenatal and postnatal brain development is well documented in the animal literature. In earlier studies using positron emission tomography (PET) with the tracer alpha[(11)C]methyl-l-tryptophan (AMT), we reported global and focal abnormalities of serotonin synthesis in children with autism. In the present study, we measured brain serotonin synthesis in a large group of autistic children (n = 117) with AMT PET and related these neuroimaging data to handedness and language function. Cortical AMT uptake abnormalities were objectively derived from small homotopic cortical regions using a predefined cutoff asymmetry threshold (>2 S.D. of normal asymmetry). Autistic children demonstrated several patterns of abnormal cortical involvement, including right cortical, left cortical, and absence of abnormal asymmetry. Global brain values for serotonin synthesis capacity (unidirectional uptake rate constant, K-complex) values were plotted as a function of age. K-complex values of autistic children with asymmetry or no asymmetry in cortical AMT uptake followed different developmental patterns, compared to that of a control group of non-autistic children. The autism groups, defined by presence or absence and side of cortical asymmetry, differed on a measure of language as well as handedness. Autistic children with left cortical AMT decreases showed a higher prevalence of severe language impairment, whereas those with right cortical decreases showed a higher prevalence of left and mixed handedness. Global as well as focal abnormally asymmetric development in the serotonergic system could lead to miswiring of the neural circuits specifying hemispheric specialization.     

Evidence for coupling between glucose metabolism and glutamate cycling using FDG PET and 1H magnetic resonance spectroscopy in patients with epilepsy.

The purpose of this study was to examine the relation between glucose metabolism and glutamate concentration in the human brain, in both the normal and diseased state. Regional values of glucose metabolism measured with 2-deoxy-2[F-18]fluoro-D-glucose positron emission tomography (FDG PET) studies and single-voxel proton magnetic resonance spectroscopy (1H MRS) measurements of the glutamate/ glutamine/gamma-aminobutyric acid (Glx) tissue concentration were determined in multiple brain regions in 11 patients (5 girls and 6 boys, mean age 7.5 years) with medically intractable partial epilepsy. FDG PET and 1H MRS studies were performed in the interictal state in seven patients and in the ictal/periictal state in four patients. Regions of interest were identified in epileptic cortex (determined by intracranial and/or scalp electroencephalography) and in contralateral normal brain regions. Lower glucose metabolism and lower Glx concentrations were found in the epileptic focus than in the contralateral normal cortex in all seven patients examined in the interictal state, whereas higher glucose metabolism and higher Glx concentrations were observed in the epileptic focus in the four patients who had ictal/periictal studies. Significant correlations were found between the values of cerebral glucose utilization and Glx concentration in epileptic brain region, in nonepileptic brain regions, and in epileptic and nonepileptic regions combined. These results demonstrate a significant relation between glucose metabolism and glutamate/glutamine concentration in normal and epileptic cerebral cortex. This relation is maintained in both the interictal and ictal states.