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.     

Abnormal cerebral hemodynamics during attacks of alternating hemiplegia

Frequent episodes of bilateral weakness and apathy, followed later by hemiplegia of alternating sides were observed in a now 32-month-old girl. Transcranial Doppler ultrasonography showed reduced flow velocities in the middle cerebral artery of the affected side during a hemiplegic attack and increased flow velocities at different sites of the basilar artery during a bilateral episode. These abnormal cerebral hemodynamics appear to indicate that alternating hemiplegia and some forms of migraine have a similar pathophysiology.     

Focal brain dysfunction in a 41-year old man with familial alternating hemiplegia

The acute pathophysiologic changes during hemiplegic spells and the long-term outcome of alternating hemiplegia remain obscure. In a 41-year-old male with familial alternating hemiplegia we found an increase in right frontal cerebral blood flow 3 h into a 5-h left hemiplegic episode. A repeat high-resolution brain SPECT study performed 26 h after the resolution of the left hemiplegia revealed normalization of the frontal blood flow accompanied by hyperperfusion in the right parietal lobe. An interictal SPECT scan several weeks later showed no asymmetries. Head CT and MRI scans were negative. Neuropsychologic assessment and neurologic examination revealed evidence of a diffuse disorder which predominantly involved the right hemisphere. To our knowledge, there are no previous correlative studies of serial highresolution brain SPECT with MRI, or of detailed neuropsychologic assessment, in adult patients with such an advanced course of alternating hemiplegia of childhood.     

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.     

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.     

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.     

An autosomal dominant syndrome of hemiplegic migraine,nystagmus, and tremor

A mother and son suffer from hemiplegic migraine with onset in childhood. Both have nystagmus which has not changed for many years, but the date of onset is uncertain. They have an asymmetrical tremor, clinically indistinguishable from essential tremor. Neuroophthalmological examination revealed inability to produce, smooth pursuit, gaze-paretic nystagmus, rebound nystagmus, failure of fixation suppression of the vestibuloocular reflex both horizontally and vertically, and, low gain of the optokinetic system. These abnormalities, confirmed by electrooculography, are commonly seen in disease of the cerebellum and brainstem. Treatment with propranolol and pizotyline lessened the number of episodes of hemiplegia and improved the tremor. Hemiplegic migraine has been reported in association with nystagmus, retinal degeneration, deafness, and ataxia in varying combinations in three other families with autosomal dominant inheritance. These associated neurological manifestations likely represent system degenerations rather than the effect of repeated ischemia imputable to the migraine itself. The syndrome of hemiplegic migraine, tremor, and ocular smooth pursuit system disorder seen in this family appears to be inherited as a single autosomal dominant trait, although more than one autosomal dominant gene may be involved.     

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.     

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.     

Familial hemiplegic migraine,nystagmus, and cerebellar atrophy

Familial hemiplegic migraine (FHM) is an autosomal dominant disorder characterized by transient hemiplegia during the aura phase of a migraine attack. Nystagmus has been reported in individuals affected with this disorder, but the origin of the ocular motility findings is unknown. A three-generation family with FHM is described and clinical histories are outlined. Ocular motility evaluations were performed on 7 family members, 5 with a history of hemiplegic migraine and 2 without history of migraine. All affected family members had abnormal eye movements consistent with vestibulocerebellar dysfunction. Magnetic resonance imaging scans in affected family members revealed cerebellar vermian atrophy. DNA linkage analysis revealed a common marker in all the affected family members on chromosome 19. We suggest that the hemiplegic migraine attacks and the cerebellar degeneration are linked genetically and that the eye movements are not the ischemic sequelae of recurrent migraine. Strikingly similar ocular motility findings and cerebellar degeneration are reported in both FHM and a genetically related disorder, hereditary paroxysmal cerebellar ataxia (HPCA). The significance of these similarities is discussed along with a proposed pathophysiology for FHM.     

Hemiconvulsion-hemiplegia-epilepsy syndrome associated with CACNA1A S218L mutation

Hemiconvulsion-hemiplegia-epilepsy syndrome involves sudden and prolonged unilateral seizures, followed by transient or permanent hemiplegia and epilepsy during infancy or early childhood. Some patients with familial hemiplegic migraine and demonstrating the S218L mutation in CACNA1A experience severe attacks with unilateral cerebral edema after trivial head trauma. We report on a 5-year-old Japanese girl presenting with hemiconvulsion-hemiplegia-epilepsy syndrome after infection with parvovirus B19. Magnetic resonance imaging performed 2 days after admission revealed cerebellar atrophy and marked hyperintensity in the left hemisphere on T₂-weighted and diffusion-weighted imaging. Magnetic resonance angiography performed 7 days after admission demonstrated obliteration of the left proximal middle cerebral artery in the acute phase. However, this finding was not evident on brain angiography performed 25 hours after magnetic resonance angiography. Genetic analysis of familial hemiplegic migraine revealed a heterozygous S218L mutation in CACNA1A. Taken together, these results suggest that vasospasms of cerebral vascular smooth muscle, with possible cortical spreading depression, may have caused the hemiconvulsions and hemiplegia in the left hemisphere. This case report is the first, to the best of our knowledge, to associate CACNA1A with hemiconvulsion-hemiplegia-epilepsy syndrome and familial hemiplegic migraine, and to suggest that similar pathogenic mechanisms may underlie these two 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.     

Alternating hemiplegia of childhood: no mutations in the glutamate transporter EAAT1

Alternating hemiplegia of childhood (AHC) is a severe brain disorder, mainly characterised by episodes of hemiplegia, progressive mental retardation, and other severe paroxysmal and permanent neurological symptoms. Clinically and genetically, there is some overlap with sporadic (SHM) and familial (FHM) hemiplegic migraine, a severe monogenic subtype of migraine. Although no mutations were detected in the FHM1 CACNA1A and FHM2 ATP1A2 genes in sporadic AHC patients, a mutation was found in the FHM2 ATP1A2 gene in a family with AHC. Recently, a missense mutation was found in the SLC1A3 gene that encodes the glutamate transporter EAAT1, in a patient with alternating hemiplegia, episodic ataxia, seizures, and headache. Because of the remarkable clinical similarities and the potential role of glutamate in AHC, we analysed six sporadic patients with AHC for mutations in the SLC1A3 gene. No mutations were found. The SLC1A3 EAAT1 glutamate transporter gene does not seem to be involved in the pathogenesis of AHC.     

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.     

Recurrent episodes of coma: an unusual phenotype of familial hemiplegic migraine with linkage to chromosome 1

Over a period of ten years, a boy had several episodes of coma, lasting three to five days. Each episode was preceded by hemiparesis or paresthesias, aphasia, headaches and behavioural changes, with subsequent loss of consciousness. Partial seizures occurred during the first episode. A history of migraine or hemiplegic migraine was found in several members of the family. Linkage to chromosome 1q21-23, where a gene for familial hemiplegic migraine has been mapped, was shown in this family.     

Transient exacerbation of hemiplegia following minor head trauma in Sturge-Weber syndrome

Sturge-Weber syndrome (SWS) is a sporadic disorder characterized by naevus (port wine stain), a pial angioma, and glaucoma. The angioma comprises abnormal tortuous vessels on the leptomeninges with underlying brain gliosis, calcification, and atrophy. The cerebral angioma is commonly unilateral but may be bilateral. Hemiplegia usually follows recurrent hemiconvulsions and may be related to venous stasis. The hemiplegia can be static, progressive, or fluctuating. Transient worsening of the hemiplegia can be seen with seizures and episodes resembling hemiplegic migraine. We report five patients (four females, one male) with SWS who have had transient worsening of hemiplegia following minor head injuries, occurring between the ages of 10 months and 12 years (median age 4y 6mo). An additional pilot survey suggests that this may affect up to 20% of patients.     

Benign paroxysmal torticollis of infancy: four new cases and linkage to CACNA1A mutation

Benign paroxysmal torticollis of infancy (BPTI) is a disorder characterized by recurrent episodes of head tilt secondary to cervical dystonia. Attacks are often accompanied by vomiting, pallor, and ataxia, settling spontaneously within hours or days. Episodes begin within the first 12 months of life and resolve by 5 years. We report four patients with BPTI. Symptoms started from 3 months of age, with head tilting lasting between 10 minutes and 2 months; the shorter episodes were followed by vomiting, apathy, and unsteadiness. Head tilt became less prominent after infancy, replaced by vertigo and eventually by migraine headaches. Two patients came from a kindred with familial hemiplegic migraine linked to CACNA1A mutation. BPTI may be regarded as a migraine aura equivalent. The syndrome poses interesting questions regarding varying phenotypic expression of calcium channelopathies at different stages of development.     

Hemiplegic migraine: hyperperfusion and abortive therapy with intravenous verapamil

A 20-year-old female with hemiplegic migraine was treated during an acute attack with intravenous verapamil, which reproducibly resolved the headache within 20 min but did not affect her hemiplegia. Magnetic resonance (MR) and computed tomographic (CT) angiography and perfusion performed during the attack showed vasodilation and hyperperfusion. Cerebral hyperperfusion concurrent with hemiplegia suggests a dissociation between cerebral perfusion and neuronal function in hemiplegic migraine. The beneficial effect of verapamil on headache but not hemiplegia suggests a distinct mechanism for pain and neuronal dysfunction in hemiplegic migraine, with the beneficial effect on pain not due to vasodilation.     

Sporadic hemiplegic migraine presenting as acute encephalopathy

A 10-year-old boy with psychomotor developmental delay and cerebellar vermis atrophy developed right hemiplegia with vomiting, unconsciousness, convulsions, and late-onset fever. Slow delta activity was noted over the left hemisphere on electroencephalography, and neuroimaging revealed swelling of the left temporo-occipital cerebral cortex with restricted diffusivity, successive transient cortical atrophy, and hyperperfusion over the left cerebral hemisphere. Interleukin-6 was elevated in the cerebrospinal fluid. The acute symptoms resolved completely within 3 weeks after onset, but hypoperfusion persisted in the left posterior cortex thereafter. Another episode with transient left hemiplegia appeared 7 months later, followed by recurrence of migraine attacks. Analysis of the CACNA1A gene revealed a mutation of c.1997 C>T (p.T666M). None of his family members had migraine. This case represents an unusual evolution of sporadic hemiplegic migraine with manifestations of acute encephalopathy, for which the role of migraine-related inflammatory process is assumed.     

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.