Benign nocturnal alternating hemiplegia of childhood: The first clinical report with paroxysmal events home‐video recordings

Benign familial nocturnal alternating hemiplegia of childhood (BNAHC) is a rare disorder characterized by recurrent attacks of hemiplegia, arising from sleep without progression to neurological or intellectual impairment. It is distinct from the malignant, relatively more common, alternating hemiplegia of childhood (AHC), complicated by developmental deterioration, cognitive impairment, and permanent neurological deficits such as choreoathetosis. The authors add a new case of BNAHC to the pertinent literature and report, for the first time, a video with the typical nocturnal hemiplegic attacks in order to improve knowledge about this disorder among child neurologists and pediatricians and increase the possibility of clarifying its pathogenesis and molecular basis. © 2008 Movement Disorder Society     

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: Two cases with positive evolution

Benign nocturnal alternating hemiplegia (BNAH) of childhood is distinct from the classic form of malignant alternating hemiplegia of childhood [1]. It is characterized by hemiplegic attacks occurring exclusively during sleep [2]. It can be misdiagnosed as migraine, nocturnal frontal lobe epilepsy, benign rolandic epilepsy, Panayiotopoulos syndrome, or sleep-related movement disorder [1], [2], [3] and [4]. Only nine patients have been described to date, with typically, a normal development [1], [5], [6] and [7]. In order to insist about the benignity of the affection, we report two cases: a new three-year-old boy suffering from BNAH and a patient already published to show positive evolution at fourteen years of age. BNAH is a rare disorder but may be underdiagnosed. Making an early diagnosis can help to describe to the parents the good prognosis without treatment.     

Alpha[11C] methyl-L-typtophan positron emission tomography in patients with alternating hemiplegia of childhood

Based on previous reports suggesting a role of the neurotransmitter serotonin in the pathomechanism of alternating hemiplegia of childhood and speculation that it may be a migraine variant, we measured brain serotonin synthesis in children with alternating hemiplegia of childhood. Clinical and neurodevelopmental data, as well as standard uptake values in 25 brain regions and whole-brain serotonin synthesis capacity (unidirectional uptake rate constant or K-complex), were assessed in six patients with alternating hemiplegia of childhood (three girls and three boys; mean age = 7 6/12 years) using alpha[11C]methyl-L-tryptophan positron emission tomography (PET). The PET studies were performed interictally in three patients, during the ictal state in two patients, and postictally in one patient. The PET data were compared to those obtained interictally from six age-matched patients with focal epilepsy (two girls and four boys; mean age = 7 8/12 years) and six non-age-matched apparently normal siblings of autistic children (two girls and four boys; mean age = 9 11/12 years). Patients with alternating hemiplegia of childhood studied in the ictal or postictal state showed increased serotonin synthesis capacity in the frontoparietal cortex, lateral and medial temporal structures, striatum, and thalamus when compared to controls, and subjects with alternating hemiplegia of childhood studied interictally. The involvement of these brain regions was consistent with the semiology of the hemiplegic attacks. In patients with interictal studies and in the controls, the PET scans revealed similar and bilaterally symmetric regional patterns of serotonin synthesis capacity. Increased whole-brain serotonin synthesis capacity (reported in migraine subjects without aura) was not found in the alternating hemiplegia of childhood group. There was no correlation between the neurodevelopmental scores and regional standard uptake values; however, patients with a larger estimated lifetime attack number showed greater delay in communication (P = .005) and daily living skills (P = .042). These studies suggest increased regional serotonergic activity associated with attacks in alternating hemiplegia of childhood. Furthermore, the attack number may have an effect on neurodevelopmental delay, thus supporting the notion that alternating hemiplegia of childhood may be a progressive disorder.     

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.     

Topiramate: a new agent for patients with alternating hemiplegia of childhood

Alternating hemiplegia of childhood is a rare syndrome characterized by the onset, before 18 months of age, of frequent attacks of alternating paralysis. Here we report the efficacy of topiramate in four patients with alternating hemiplegia of childhood (AHC) that did not respond to flunarizine, as well as in two newly diagnosed patients. Following treatment with topiramate, the frequency and duration of hemiplegic attacks significantly improved in all patients. Additional symptoms such as seizures, migraine, involuntary movements, autonomic symptoms, and impaired mental development also improved. Topiramate is worth trying when treating patients with AHC as a first trial, or a substitute for flunarizine once the latter agent loses effect.     

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.     

Alternating hemiplegia of childhood: a syndrome inherited with an autosomal dominant trait

Alternating hemiplegia of childhood is a rare disorder characterized by recurrent attacks of hemiplegia affecting either side of the body, oculomotor and autonomic disturbances, movement disorders, and progressive cognitive impairment. We report on one family with autosomal dominant alternating hemiplegia. The disorder was first recognized in a 9-year-old child, the third son of the family, who presented with learning disability, tonic-clonic seizures, dystonic attacks, and episodes of alternating hemiplegia starting at the age of 2 1/2 years. His mother and three brothers had similar symptoms. The maternal uncle, who has learning disability, had experienced multiple dystonic attacks. Tests performed on the family, including computerized tomography, magnetic resonance imaging, and magnetic resonance angiography of the brain as well as metabolic evaluation, were normal. Cytogenetic analysis was normal and mitochondrial DNA analysis revealed no deletions or mutations in the four affected family members and the grandmother. An autosomal dominant mode of inheritance is suggested by the fact that both sexes are affected in two generations.     

An 11-year follow-up study of neonatal-onset, bath-induced alternating hemiplegia of childhood in twins

The authors previously reported on the initial manifestations in a set of female twins, who presented soon after birth with bath-induced paroxysmal events each time they were immersed in a warm water bath. These episodes progressively ceased by the age of 36 months, replaced by paroxysmal episodes of alternating hemiplegia unrelated to water immersion. By age 4 years, the twins developed the classic features of alternating hemiplegia of childhood. Clinical outcomes at the age of 11 years are now reported. Standard and video-electroencephalograms showed a large, slow background activity followed by lower amplitude waves without focal abnormalities or other abnormal findings. This represents the first report on (a) alternating hemiplegia of childhood started with bath-induced paroxysmal episodes; (b) this condition in monozygotic twins; and (c) an 11-year follow-up study in which the twins continue to experience episodes of alternating hemiplegia in the setting of baseline cognitive impairment without epileptic episodes.     

三例儿童交替性偏瘫的回顾性分析

目的探讨儿童交替性偏瘫病因、临床特点、治疗效果。方法回顾性分析3例儿童交替性偏瘫患者的病因、临床表现及疗效。结果本组3例患者起病年龄均小于18个月,反复发作的交替性偏瘫；进行性的智能障碍,其中1例伴有短暂眼球震颤及眼球活动障碍,1例伴有张力障碍性姿势异常；睡眠可缓解无力及锥体外系症状,应用氟桂嗪治疗后,2例患者发作频率及持续时间降低,1例无效。结论本病病因不明,多为散发,临床表现为18月内起病的发作性交替性偏瘫,辅助检查无特征性改变,氟桂利嗪治疗部分有效。     

儿童交替性偏瘫六例分析

目的探讨儿童交替性偏瘫（ＡＨＣ）的临床特点及治疗方法。方法对６例ＡＨＣ患儿的临床资料进行分析。结果６例患儿的临床特征为出生后１８个月起内病，频繁发作，持续数分钟至数小时；短暂的眼球震颤，肌张力异常，舞蹈徐动样动作，植物神经机能紊乱和认知机能减退；睡眠可缓解无力及锥体外系症状。应用氟桂嗪治疗后，１例患儿发作完全停止，其余５例患儿均显示发作频率和持续时间降低。结论本病的主要特征为１８个月内起病的发作性交替性偏瘫，伴锥体外系症状及智力障碍，氟桂嗪治疗本病有效     

Brainstem auditory evoked potentials in alternating hemiplegia: ictal vs interictal assessment in one case

The authors report a case of alternating hemiplegia (AH) in a 3yr 6m old boy who had presented, from the age of 4 months on, episodes of alternating hemi- or quadriplegia. Brainstem auditory evoked potentials were recorded both in the interictal state and, for the first time, during an attack. There was no significant difference between the two states. These findings suggest that a massive involvement of the posterior vascular territory is not likely to be associated with attacks in AH.     

Successful trial of amantadine hydrochloride for two patients with alternating hemiplegia of childhood

We report here the efficacy of amantadine hydrochloride for two patients with alternating hemiplegia of childhood (AHC) that did not respond to flunarizine. Amantadine was administered to one patient at age one year and seven months and to the other at age 25 years. The frequencies and duration of the hemiplegic attacks significantly improved in both patients. However, the attacks gradually returned to the previous level after a significant reduction in seizures for three years in the younger patient with ongoing AHC. Our therapeutic results further support the hypothesis that glutamate and NMDA receptors are involved in inducing alternating hemiplegic attacks, because amantadine as well as its derivative, memantine, are clinically available non-competitive N-methyl-D-aspartate (NMDA) receptor antagonists, with neuroprotective effects. Amantadine is worth trying when treating patients with AHC as a first trial or a substitute for flunarizine once the latter agent looses effect.     

A syndrome of autosomal dominant alternating hemiplegia: clinical presentation mimicking intractable epilepsy; chromosomal studies; and physiologic investigations.

We report the familial occurrence and apparent autosomal dominant inheritance of alternating hemiplegia of childhood. The proband, a 9-year-old boy, presented with developmental retardation, rare tonic-clonic seizures, and frequent episodes of flaccid alternating hemiplegia that had been presumed to represent postictal paralysis. The hemiplegia spells, which started in his first year, did not respond to multiple antiepileptics. Between attacks, there was choreoathetosis and dystonic posturing. Father, brother, paternal uncle, and paternal grandmother had similar histories of alternating hemiplegia. Investigations included negative CT, metabolic, and coagulation studies. EEG and SPECT 99mTc exametazime scanning failed to reveal any significant slowing or any major changes in cortical perfusion during hemiplegia as compared with nonhemiplegic periods. The karyotype revealed a balanced reciprocal translocation, 46,XY,t(3;9)(p26;q34) in the patient, in all the affected living relatives, and in one apparently unaffected sibling. The asymptomatic mother had a normal karyotype. Analysis of DNA markers was consistent with the karyotype results. Both affected siblings were treated with and responded to flunarizine therapy, with a greater than 70% decrease in attack frequency. Documented flunarizine trough serum concentrations were 28.9 ng/ml in the proband and 6.6 ng/ml in his brother.     

Alternating hemiplegia of childhood: clinical manifestations and long-term outcome

We present our analysis of 44 patients with alternating hemiplegia of childhood. The clinical course usually consisted of three phases. The first was dominated by abnormal eye movements and dystonic episodes, the second by hemiplegic spells and psychomotor regression, and the third by persistent developmental delay and fixed neurologic deficits. The age of onset was 0-54 months (mean = 7.9 +/- 13 months). The presenting signs included abnormal ocular movements in 65%, dystonia in 60%, and hemiplegia in 32%. Patients with an early onset of the disorder and an early appearance of hemiplegic spells faired the poorest developmentally. Developmental delay was present in 91%, ataxia in 68%, choreoathetosis in 50%, and seizures in 18%. Laboratory investigations suggested mitochondrial abnormalities and cerebrovascular dysfunction in several patients. Numerous therapies were largely ineffective. Flunarizine reduced the duration, severity, and frequency of the hemiplegic attacks in 78%. Patients who received flunarizine did not differ developmentally from those who did not. Our data suggest that flunarizine does not adversely affect and may favorably influence the outcome in patients with alternating hemiplegia of childhood. Additionally, the occurrence of autosomal-dominant cases of the syndrome, although rare, suggests that, in addition to mitochondrial dysfunction, genetic factors may be important.     

123I-iodoamphetamine SPECT brain imaging in alternating hemiplegia

Alternating hemiplegia of childhood is an unusual disorder characterized by early onset (occurring before 18 months of age); repeated attacks of hemiplegia involving both sides of the body; other paroxysmal phenomena, such as tonic stiffening, dystonic posturing, choreoathetoid movements, ocular motor abnormalities, and autonomic disturbances, in association with bouts of hemiplegia or occurring independently; and evidence of mental or neurologic deficits. A girl was examined because of left hemiplegia at the age of 16 months. The patient had begun exhibiting episodes of alternating hemiplegia at approximately 4 months of age. They consisted of tonic stiffening and dystonia of the right or left extremities, lasting from 30 min to several hours and followed by residual hemiparesis. They were invariably accompanied by ocular motor abnormalities. Magnetic resonance imaging, computed tomography, and angiography all were normal. Single proton emission computed tomography brain images during an acute episode of right hemiplegia demonstrated hypoperfusion of the left cerebral hemisphere. Following improvement of the hemiplegia, the patient was re-evaluated. The uptake of the radiotracer in the left hemisphere was increased. The scan did not demonstrate significant asymmetry in cerebral perfusion.     

A boy with nystagmus, refractory dystonia and apneic attack due to alternating hemiplegia of childhood

We herein report the findings of a 2-year-6-month-old boy, who had been experiencing monocular pendular nystagmus, strabismus, and episodic eye deviation nystagmus, intractable dystonia and apneic attack which all began when he was 2 days of age. He underwent a complete blood count test, blood chemistry test, analysis of amino acids in the blood and urine, analysis of pyruvate/lactate in blood and cerebrospinal fluid, head computed tomography and magnetic resonance imaging and no abnormal results were identified. His attacks were resistant to multiple antiepileptic and dopaminergic drugs. He showed transient left and/or right hemiplegia after nystagmus, dystonia and/or apneic attacks at 8-months of age with retardation in intelligence. We diagnosed him to have alternating hemiplegia of childhood (AHC). We were unsure how to deal with his attacks after he was discharged from the hospital, however, resuscitation with the ambu bag by his mother at home and the intravenous infusion of diazepam or thiamylal at the hospital together was proven to be an effective method for treating his severe apneic attacks. The effect of diazepam and amantadine on these attacks was transient, however, the administration of flunarizine with amantadine resulted in an improvement in his attacks. We therefore consider the administration of flunarizine to be essential for the effective treatment of AHC in this case.     

Evidence for mitochondrial dysfunction in patients with alternating hemiplegia of childhood

Phosphorus magnetic resonance spectra of resting muscle were obtained from 4 patients with alternating hemiplegia of childhood. All patients had abnormally high resonance intensities from inorganic phosphate and an abnormally law calculared cytosolic phosphorylation potential. Tow of the 4 patients had abnormally law resonance intensities from phosphocreatine and an abnormally high calculated cytosolic free adenosine diphosphare conecntration. These abnormalities are indicative of mitochondrial dysfunction. The combination of a central nervous system disorder and evidence of mitochondrial dysfunction in muscle suggests that alternating hemiplegia of childhood may represent a previously unrecognized phenotype of mitochondrial disease.     

Epileptic seizures difficult to differentiate from alternating hemiplegia in infants: a case report

A child with epileptic seizures had a clinical course similar to that of alternating hemiplegia of infancy (AHI). Tonic hemiplegia began at 2 months of age, and atonic alternating hemiplegia and tetraplegic attacks began at 2 years of age. Clinical findings were paroxysmal ocular movement abnormalities, choreoathetotic involuntary movements, and severe developmental retardation. An interictal EEG at 6 years of age showed multiple independent spike discharges. An ictal EEG showed diffuse irregular spike-wave and slow wave bursts following focal spikes. The present case suggests that a long-term extensive follow-up is necessary to differentiate epileptic seizures from AHI.