A Case of Posterior Circulation Embolism Due to a Subtype of Bow Hunter's Syndrome Diagnosed by Non-Invasive Examination.

Bow hunter's syndrome is the mechanical compression of the vertebral artery due to cervical rotation, resulting in ischemic symptoms in the vertebrobasilar artery territory. However, some cases present without typical symptoms and exhibit compression of the non-dominant side of the vertebral artery. We encountered a case of posterior circulation embolism due to a subtype of bow hunter's syndrome in a 74-year-old man. Although the right vertebral artery was not visualized on time-of-flight magnetic resonance angiography in the neutral position, duplex ultrasonography and time-of-flight magnetic resonance angiography in the left cervical rotation position showed blood flow in the right vertebral artery. In this case, blood flow in the contralateral vertebral artery was normal, and typical bow hunter's syndrome symptoms did not occur. In a case of posterior circulation embolism with undetermined etiology, wherein the routine duplex ultrasonography and time-of-flight magnetic resonance angiography results were inconclusive, additional testing with head positioning led to the diagnosis of a subtype of bow hunter's syndrome.

Kleine-Levin syndrome elicited by encephalopathy with reversible splenial lesion.

Kleine-Levin syndrome is a rare sleep disorder of unknown etiology characterized by repetitive episodes of hypersomnia between asymptomatic periods. We report the case of a 13-year-old girl who presented with drowsiness triggered by influenza A as the first episode. Magnetic resonance imaging (MRI) on day 6 showed transient reduction of diffusion in the corpus callosum splenium. The patient was diagnosed with encephalopathy with a reversible splenial lesion. The symptoms resolved after 10 days, but additional episodes of hypersomnia lasting 5-10 days occurred 1, 5, 6, 11, 13, and 25 months after the first episode. MRI during hypersomnia indicated no lesions, and sleep duration and cognition were normal between episodes. The patient was diagnosed with Kleine-Levin syndrome. Electroencephalographic and clinical findings during the first episode were similar to those during the other episodes. Encephalopathy with a splenial lesion and Kleine-Levin syndrome may have similar pathological mechanisms causing a disturbance in consciousness.

De novo GABRA1 mutations in Ohtahara and West syndromes.

OBJECTIVE: GABRA1 mutations have been identified in patients with familial juvenile myoclonic epilepsy, sporadic childhood absence epilepsy, and idiopathic familial generalized epilepsy. In addition, de novo GABRA1 mutations were recently reported in a patient with infantile spasms and four patients with Dravet syndrome. Those reports suggest that GABRA1 mutations are associated with infantile epilepsy including early onset epileptic encephalopathies. In this study, we searched for GABRA1 mutations in patients with infantile epilepsy to investigate the phenotypic spectrum of GABRA1 mutations. METHODS: In total, 526 and 145 patients with infantile epilepsy were analyzed by whole-exome sequencing and GABRA1-targeted resequencing, respectively. RESULTS: We identified five de novo missense GABRA1 mutations in six unrelated patients. A p.R112Q mutation in the long extracellular N-terminus was identified in a patient with infantile epilepsy; p.P260L, p.M263T, and p.M263I in transmembrane spanning domain 1 (TM1) were identified in three unrelated patients with West syndrome and a patient with Ohtahara syndrome, respectively; and p.V287L in TM2 was identified in a patient with unclassified early onset epileptic encephalopathy. Four of these mutations have not been observed previously. SIGNIFICANCE: Our study suggests that de novo GABRA1 mutations can cause early onset epileptic encephalopathies, including Ohtahara syndrome and West syndrome.

High-dose phenobarbital with intermittent short-acting barbiturates for acute encephalitis with refractory, repetitive partial seizures.

Acute encephalitis with refractory, repetitive partial seizures (AERRPS) is characterized by repetitive seizures during the acute and chronic phases and has a poor neurological outcome. Burst-suppression coma via continuous i.v. infusion of a short-acting barbiturate is used to terminate refractory seizures, but the severe side-effects of short-acting barbiturates are problematic. We report on a 9-year-old boy with AERRPS who was effectively treated with very-high-dose phenobarbital (VHDPB) combined with intermittent short-acting barbiturates. VHDPB side-effects were mild, especially compared with those associated with continuous i.v. infusion of short-acting barbiturates (dosage, 40-75 mg/kg/day; maximum blood level, 290 µg/mL). Using VHDPB as the main treatment, short-acting barbiturates were used intermittently and in small amounts. This is the first report to show that VHDPB, combined with intermittent short-acting barbiturates, can effectively treat AERRPS. After treatment, convulsions were suppressed and daily life continued, but intellectual impairment and high-level dysfunction remained.

[Varicella-zoster meningoencephalitis and vasculitis after treatment with amenamevir to herpes zoster in the trigeminal nerve area].

A 78-year-old woman was diagnosed with herpes zoster in the first branch of the trigeminal nerve and was treated with amenamevir. Subsequently, she was hospitalized for postherpetic neuralgia. Fever and unconsciousness were observed, and a diagnosis of varicella-zoster virus meningoencephalitis and vasculitis was made. In addition to the antithrombotic therapy, she was treated with intravenous acyclovir and steroid pulse therapy; however, her unconsciousness persisted. Amenamevir was not transferrable to the spinal fluid and resulted in an incomplete treatment of herpes zoster in the cerebral nerve region, suggesting that this case may be related to the severe course of the disease.

Acute encephalopathy with a truncation mutation in the SCN1A gene: a case report.

A girl aged 1 year 9 months had recurrent episodes of febrile status epilepticus. She recovered completely after the first three episodes. However, at 9 months she developed acute encephalopathy resulting in severe neurologic sequelae. Diffusion-weighted magnetic resonance imaging revealed diffuse high-intensity signals over the cortex and subcortical white matter in the acute phase and severe diffuse cerebral atrophy in the chronic phase. Mutations were detected in the neuronal voltage-gated sodium channel alpha subunit type 1 (SCN1A) gene. SCN1A sequence analysis revealed a truncation mutation:e x1-c.126Adel (D43fs). Our patient was likely afflicted by severe myoclonic epilepsy in infancy, and the fourth episode of status epilepticus was similar to acute encephalopathy. This report provides further insight into the molecular pathophysiology underlying acute encephalopathy.

[A case of cerebral infarction in young adult resulting in thrombotic occlusion of vertebral artery due to repeated contact stimulation of cervical rotation accompanied to systemic malformations such as atlantoaxial subluxation and atlas dysplasia].

A 23-year-old man admitted to our hospital with headache and dysarthria. Head MRI showed multiple acute cerebral infarctions in the right posterior circulation. Atlantoaxial dislocation, atlas dysplasia and thrombotic occlusion of right vertebral artery (VA), and blood flow disruption due to cervical rotation was observed. The axial dental process bordered to the right VA, and repeated contact stimulation by cervical rotation may cause intimal damage resulting in thrombotic occlusion. In this case, various systemic malformations such as atrial septal defect, atlas posterior arch hypoplasia, bovine left common carotid bifurcation malformation, double inferior vena cava and horseshoe kidney may have been congenital syndromes. Atlantoaxial dislocation may be an important and under-recognized cause of stroke in young adults.

[Amyloid ß related angitis without marked leukoencephalopathy].

An 86-year-old woman was admitted to our hospital with headache and acute detarioration of consciousness. Cerebral microbleeds (CMBs) dominated the occipital lobe on the head MRI, revealing white matter lesions. It was accompanied by gadolinium (Gd) imaging effect in the leptomeninges and some CMBs. She was clinically diagnosed with amyloid ß-related vasculitis and a good outcome was obtained with steroid therapy. Even when symptoms re-exacerbated, exacerbation of the contrast effect of CMBs was observed, but no white matter lesions appeared, and leptomeningeal enhancement did not change remarkably throughout the entire course.

Beta-phenylethylamine inhibits K+ currents in neocortical neurons of the rat: a possible mechanism of beta-phenylethylamine-induced seizures.

beta-Phenylethylamine (beta-PEA), an endogenous amine synthesized in the brain, serves as a neuromodulator and is involved in the pathophysiology of various neurological disorders such as depression, schizophrenia, and attention-deficit hyperactivity disorder. beta-PEA fully exerts the physiological effects within the nanomolar concentration range via the trace amine receptors, but beta-PEA also causes convulsions at much higher concentrations via an as yet unknown mechanism. To investigate the electrophysiological mechanism by which beta-PEA induces convulsions, we examined the effect of beta-PEA on ionic currents passing through the cell membrane of dissociated rat cerebral cortical neurons, using a patch-clamp technique. The external application of beta-PEA suppressed ionic currents which continuously flowed when the membrane potential was held at -25 mV. The suppression was in a concentration-dependent manner and a half-maximal effective concentration was 540 muM. These currents suppressed by beta-PEA consisted of two K(+) currents: a time- and voltage-dependent K(+) current (M-current) and a leakage K(+) current. The suppression of the M-current reduces the efficacy of the current in limiting excessive neuronal firing, and the suppression of the leakage K(+) current can cause membrane depolarization and thus promote neuronal excitation. Reducing both of these currents in concert may produce neuronal seizing activity, which could conceivably underlie the convulsions induced by high-dose beta-PEA.

[Cerebrospinal fluid leakage and abducens nerve palsy caused by bowling activity].

Cerebrospinal fluid leakage can develop due to traffic trauma or lumbar puncture; however, in many cases, it develops spontaneously without any obvious cause. This report describes a case of cerebrospinal fluid leakage caused by bowling activity. A 57-year-old woman adjusted her bowling form, which led to the development of an orthostatic headache and double vision. Cerebrospinal fluid leakage and right abducens nerve palsy was diagnosed, which was resistant to conservative treatment. An epidural blood patch was performed, leading to an improvement in the headache and abducens nerve palsy. The hypotension and nerve palsy may have been caused by small amounts of cerebrospinal fluid leakage due to repeated traction of the brachial plexus and nerve root resulting from an irregular bowling form. To the best of our knowledge, there are no reported cases of cerebrospinal fluid leakage caused by bowling; therefore, this is a valuable case to investigate the mechanism of onset. Similar mechanisms may have remained undiscovered in other cases of spontaneous intracranial hypotension.

A patient with Muenke syndrome manifesting migrating neonatal seizures.

We report a patient with Muenke syndrome who had repetitive apneic spell followed by focal status epilepticus in the early infancy. Ictal EEG showed focal spikes bursts originated from the left hemisphere and sifted to the right hemisphere, during which he had migrating tonic seizures from right side of the body to the left side of the body. Brain MRI showed abnormal development of bilateral hippocampus, which was characterized as abnormal folding of hippocampal gyri. However, the long-term seizure prognosis was favorable. Results from this and previous studies failed to support the notion that FGFR3 (P250) mutation results in epileptic encephalopathy.

Initial vasodilatation in a child with reversible cerebral vasoconstriction syndrome.

We describe the case of a 10-year-old boy who developed reversible cerebral vasoconstriction syndrome (RCVS) after cerebellitis. He received intravenous immunoglobulin and methylprednisolone to treat the cerebellitis. However, he then presented with a sudden severe headache, vomiting, and generalized tonic-clonic seizure. Brain magnetic resonance angiography (MRA) initially revealed diffuse cerebral vasodilatations, and diffuse multifocal segmental vasoconstrictions developed several days later. His clinical symptoms gradually resolved after several days, in the absence of any specific therapy. MRA performed 46days after symptom onset showed that the multifocal segmental vasoconstrictions had resolved, suggesting a diagnosis of RCVS. The imaging features of RCVS include multifocal segmental vasoconstriction. However, our case suggests that diffuse cerebral vasodilatation may in fact be evident during the early stage of disease.

Successful treatment of a 2-year-old girl with intractable myasthenia gravis using tacrolimus.

We used tacrolimus to successfully treat a patient with childhood-onset oropharyngeal myasthenia gravis (MG). A girl (2 years, 5 months old) with oropharyngeal MG responded partially to treatment including pyridostigmine bromide, intravenous immunoglobulin, and prednisolone (2 mg/kg/day) for 7 weeks, but this resulted in worsening of her eye symptoms. By contrast, tacrolimus at 2 mg/day resulted in complete remission of the MG, which made it possible to reduce the dose of prednisolone. This is a rare report of the use of tacrolimus as an effective treatment for patients with intractable childhood-onset MG.

Serial changes on diffusion-weighted magnetic resonance imaging in encephalitis or encephalopathy.

It is recognized that diffusion-weighted magnetic resonance imaging is a sensitive method of detecting cerebral lesions in various neurologic disorders. This report presents two patients with acute encephalitis or encephalopathy who manifested similar serial changes on diffusion-weighted magnetic resonance imaging. Clinically, Patient 1, a 2-year-old male, was diagnosed as having hemiconvulsion-hemiplegia-epilepsy syndrome and Patient 2, a 9-month-old male, acute encephalitis associated with exanthema subitum. Despite the different etiology and the distribution of lesions, diffusion-weighted magnetic resonance imaging of these two patients revealed high-intensity lesions in the subcortical white matter in the acute phase, and then in the cortex, or basal ganglia, or both. In the convalescent phase, high-intensity lesions disappeared and brain atrophy developed. These serial changes were not recognized using other conventional methods. Although the exact mechanism for these serial changes remains unknown, these changes might reflect some pathogenic mechanism in acute encephalopathy or encephalitis.

FDG-PET study of patients with Leigh syndrome.

We conducted a [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) study in five patients (median age 11 (range 4-13) years) with Leigh syndrome to evaluate its usefulness for understanding the functional brain dysfunction in this disease and in future drug trials. Four patients were found to have reported mitochondrial DNA gene mutations. The brain T2-weighted magnetic resonance imaging (MRI) showed high-intensity areas in the putamen bilaterally in five patients, caudate bilaterally in four, thalamus bilaterally in two, and brainstem in one. Cerebellar atrophy was observed in older two patients. For disease control, seven age-matched epilepsy patients who had normal MRI and FDG-PET studies were selected. For semiquantitative analysis of the lesions with decreased (18)F-FDG uptake, the mean standard uptake value (SUV) was calculated in regions of interest (ROIs) placed in each brain structure. We compared the SUV of nine segments (the frontal, temporal, parietal, and occipital lobes, thalami, basal ganglia, mid-brain, pons, and cerebellum) between patients with Leigh syndrome and controls. The glucose uptake was decreased significantly in the cerebellum and basal ganglia, which could explain the ataxia and dystonia in patients with Leigh syndrome. Although this study had some limitations, FDG-PET might be useful for evaluating the brain dysfunction and treatment efficacy of new drugs in patients with Leigh syndrome. Further study with more patients using advanced methods to quantify glucose uptake is needed before drawing a conclusion.

The effects of copper-histidine therapy on brain metabolism in a patient with Menkes disease: a proton magnetic resonance spectroscopic study.

We report on metabolic changes in the brain of a boy with Menkes disease. He was treated with parenteral copper (Cu)-histidine supplementation, from 5 months of age, and assessed with proton magnetic resonance spectroscopy ((1)H-MRS). The single-voxel (1)H-MRS before treatment revealed an accumulation of lactate and a reduced N-acetyl aspartate (NAA)/total creatine (tCr) ratio with a z-score of -3.0. During treatment, the lactate signal faded away, whereas the NAA signal gradually increased to a z-score of -1.5 at 120 days of treatment. The choline/tCr ratio did not deviate much initially (z-score +0.5), but the ratio increased markedly during treatment (z-score +4.8). Consequently, the Cu-histidine therapy initiated after the critical period still improved the neuronal metabolism, suggesting that some Cu was delivered to neurons. Nevertheless, the brain atrophy, impaired myelination, and severe neurological symptoms were not ameliorated.

Elevated serum levels of neutrophil elastase in patients with influenza virus-associated encephalopathy.

We examined serum levels of various cytokines, chemokines, growth factors, and adhesion molecules in patients with uncomplicated influenza (n=20) and influenza virus-associated encephalopathy (IE) (n=18) to understand the underlying mechanism of IE. We found that IL-1ß, IL-2, IL-5, IL-6, IL-7, IL-8, IL-10, IL-13, G-CSF, GM-CSF, TNF-α, TIMP-1, MMP-9, sE-selectin, and neutrophil elastase were elevated significantly in sera from patients with uncomplicated influenza and those with IE, compared with normal controls (n=20). Of note, neutrophil elastase, sE-selectin, IL-8, and IL-13 were elevated significantly in IE as compared with uncomplicated influenza. In the present study, for the first time, we found that serum levels of neutrophil elastase were increased in patients with IE compared with uncomplicated influenza, which suggested that cerebral endothelial damage in the development of IE was mediated by neutrophil elastase. The present study implied that anti-elastase agents are possibly an effective therapeutic protocol for IE, but this needs further elucidation.

Acute dysautonomia: complete recovery after two courses of IVIg.

An 11-year-old boy presented with acute dysautonomia manifesting as severe orthostatic hypotension following fever. Serial orthostatic tests with measurement of the coefficient of variation in the R-R intervals showed improvement after one course and complete recovery after two courses of intravenous high-dose immunoglobulin therapy (IVIg). Repeated courses of IVIg should be considered to treat this disorder if spontaneous remission does not occur.

The usefulness of subtraction ictal SPECT and ictal near-infrared spectroscopic topography in patients with West syndrome.

The recent findings on subtraction ictal SPECT and ictal near-infrared spectroscopic topography in patients with West syndrome were summarized and its availability for presurgical evaluation was discussed. The subtraction ictal SPECT study in patients with West syndrome demonstrated the cortical epileptic region and subcortical involvement, which may consist of epilepsy networks related to the spasms. Moreover, subtraction ictal SPECT may have predictive power for short-term seizure outcome. Patients with a symmetric hyperperfusion pattern are predicted to have a better seizure outcome, whereas patients with asymmetric hyperperfusion pattern may develop poor seizure control. Importantly, asymmetric MRI findings had no predictive power for seizure outcome. Multichannel near-infrared spectroscopic topography applied to the patients with West syndrome detected an increase in regional cerebral blood volume in multiple areas which were activated either simultaneously or sequentially during spasms. Topographic changes in cerebral blood volume were closely correlated with spasm phenotype, suggesting that the cortex is involved in the generation of spasms. In conclusion, subtraction ictal SPECT may be considered as a useful tool for presurgical evaluation of patients with West syndrome and investigation of the pathophysiology of spasms. The ictal near-infrared spectroscopic topography should be more investigated to see if this is useful tool for presurgical evaluation.