RNA Foci in Two bi-Allelic RFC1 Expansion Carriers

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) is a late-onset, autosomal recessive neurodegenerative disorder caused by biallelic AAGGG/ACAGG repeat expansion (AAGGG-exp/ACAGG-exp) in RFC1. The recent identification of patients with CANVAS exhibiting compound heterozygosity for AAGGG-exp and truncating variants supports the loss-of-function of RFC1 in CANVAS patients. We investigated the pathological changes in 2 autopsied patients with CANVAS harboring biallelic ACAGG-exp and AAGGG-exp. RNA fluorescence in situ hybridization of the 2 patients revealed CCTGT- and CCCTT-containing RNA foci, respectively, in neuronal nuclei of tissues with neuronal loss. Our findings suggest that RNA toxicity may be involved in the pathogenesis of CANVAS. ANN NEUROL 2024;95:607-613.

Long-read sequencing revealing intragenic deletions in exome-negative spastic paraplegias

Hereditary spastic paraplegias (HSPs) are a heterogeneous group of neurodegenerative disorders characterized by progressive spasticity and weakness in the lower extremities. To date, a total of 88 types of SPG are known. To diagnose HSP, multiple technologies, including microarray, direct sequencing, multiplex ligation-dependent probe amplification, and short-read next-generation sequencing, are often chosen based on the frequency of HSP subtypes. Exome sequencing (ES) is commonly used. We used ES to analyze ten cases of HSP from eight families. We identified pathogenic variants in three cases (from three different families); however, we were unable to determine the cause of the other seven cases using ES. We therefore applied long-read sequencing to the seven undetermined HSP cases (from five families). We detected intragenic deletions within the SPAST gene in four families, and a deletion within PSEN1 in the remaining family. The size of the deletion ranged from 4.7 to 12.5 kb and involved 1-7 exons. All deletions were entirely included in one long read. We retrospectively performed an ES-based copy number variation analysis focusing on pathogenic deletions, but were not able to accurately detect these deletions. This study demonstrated the efficiency of long-read sequencing in detecting intragenic pathogenic deletions in ES-negative HSP patients.

Reduced likelihood of the Poggendorff illusion in cerebellar strokes: a clinical and neuroimaging study

This study aimed to test our hypothesis that the cerebellum plays an important role in the generation of the optical-geometric illusion known as the Poggendorff illusion, the mechanism of which has been explained by accumulated experience with natural scene geometry. A total of 79 participants, comprising 28 patients with isolated cerebellar stroke, 27 patients with isolated cerebral stroke and 24 healthy controls, performed Poggendorff illusion tasks and 2 different control tasks. We also investigated core brain regions underpinning changes in the experience of the illusion effect using multivariate lesion-symptom mapping. Our results indicate that patients with isolated cerebellar stroke were significantly less likely to experience the Poggendorff illusion effect than patients with isolated cerebral stroke or healthy controls (74.6, 90.5 and 89.8%, respectively; F(2,76) = 6.675, P = 0.002). However, there were no inter-group differences in the control tasks. Lesion-symptom mapping analysis revealed that the brain lesions associated with the reduced frequency of the Poggendorff illusion effect were mainly centred on the right posteromedial cerebellar region, including the right lobules VI, VII, VIII, IX and Crus II. Our findings demonstrated, for the first time, that patients with cerebellar damage were significantly less likely to experience the Poggendorff illusion effect and that right posteromedial cerebellar lesions played an important role in this effect. These results provide new insight into alterations of a geometric illusion effect in patients with cerebellar disorders and pave the way for future clinical use of the illusion task to detect cerebellar abnormalities.

Periodic paralysis due to cumulative effects of rare variants in SCN4A with small functional alterations

INTRODUCTION/AIMS

Mutations in the SCN4A gene encoding a voltage-gated sodium channel (Nav1.4) cause hyperkalemic periodic paralysis (HyperPP) and hypokalemic periodic paralysis (HypoPP). Typically, both HyperPP and HypoPP are considered as monogenic disorders caused by a missense mutation with a large functional effect. However, a few cases with atypical periodic paralysis phenotype have been caused by multiple mutations in ion-channel genes expressed in skeletal muscles. In this study we investigated the underlying pathogenic mechanisms in such cases.

METHODS

We clinically assessed two families: proband 1 with HyperPP and proband 2 with atypical periodic paralysis with hypokalemia. Genetic analyses were performed by next-generation sequencing and conventional Sanger sequencing, followed by electrophysiological analyses of the mutant Nav1.4 channels expressed in human embryonic kidney 293T (HEK293T) cells using the whole-cell patch-clamp technique.

RESULTS

In proband 1, K880del was identified in the SCN4A gene. In proband 2, K880del and a novel mutation, R1639H, were identified in the same allele of the SCN4A gene. Functional analyses revealed that the K880del in SCN4A has a weak functional effect on hNav1.4, increasing the excitability of the sarcolemma, which could represent a potential pathogenic factor. Although R1639H alone did not reveal functional changes strong enough to be pathogenic, Nav1.4 with both K880del and R1639H showed enhanced activation compared with K880del alone, indicating that R1639H may modify the hNav1.4 channel function.

DISCUSSION

A cumulative effect of variants with small functional alterations may be considered as the underpinning oligogenic pathogenic mechanisms for the unusual phenotype of periodic paralysis.

[Motor Neuron Involvement in RFC1 CANVAS/Spectrum Disorders]

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is characterized by the triad of cerebellar ataxia, bilateral vestibular impairment, and sensory neuropathy. The responsible anatomical region for the sensory disturbance in CANVAS is reportedly the dorsal root ganglion, which suggests neuronopathy rather than neuropathy as the pathomechanism of this peripheral nervous system disorder. Early on, motor neuron involvement was considered rare in CANVAS. The etiology of CANVAS includes the homozygous pentanucleotide repeat expansion within the RFC1 gene, resulting in diverse phenotypes and motor deficits such as brisk reflex, extensor plantar responses, or spasticity of the upper motor neurons and muscle wasting, weakness, cramp, or fasciculation of the lower motor neurons. CANVAS patients with AAGGG repeat expansions may show motor neuron involvement, with considerable variation in the reported frequencies. In contrast, although some patients with ACAGG repeat expansions also show motor neuron involvement, its frequency remains elusive.

Sensory Ataxic Guillain-Barré Syndrome with Dysgeusia after mRNA COVID-19 Vaccination

Guillain-Barré syndrome (GBS) has occasionally occurred in people who have received coronavirus disease 2019 (COVID-19) vaccines. Dysgeusia is rare symptom of GBS. We herein report a rare case of sensory ataxic GBS with dysgeusia just after the second dose of the Pfizer-BioNTech COVID-19 vaccine. Although autoantibodies against glycolipids were not detected, immunotherapy with intravenous immunoglobulin and methylprednisolone pulse therapy effectively ameliorated the symptoms. Our report suggests that the COVID-19 vaccine may induce various clinical subtypes of GBS, including a rare variant with sensory ataxia and dysgeusia.

Repeat conformation heterogeneity in cerebellar ataxia, neuropathy, vestibular areflexia syndrome

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) is a late-onset, slow-progressing multisystem neurodegenerative disorder. Biallelic AAGGG repeat expansion in RFC1 has been identified as causative of this disease, and repeat conformation heterogeneity (ACAGG repeat) was also recently implied. To molecularly characterize this disease in Japanese patients with adult-onset ataxia, we accumulated and screened 212 candidate families by an integrated approach consisting of flanking PCR, repeat-primed PCR, Southern blotting and long-read sequencing using Sequel II, GridION or PromethION. We identified 16 patients from 11 families, of whom seven had ACAGG expansions [(ACAGG)exp/(ACAGG)exp] (ACAGG homozygotes), two had ACAGG and AAGGG expansions [(ACAGG)exp/(AAGGG)exp] (ACAGG/AAGGG compound heterozygotes) and seven had AAGGG expansions [(AAGGG)exp/(AAGGG)exp] (AAGGG homozygotes). The overall detection rate was 5.2% (11/212 families including one family having two expansion genotypes). Long-read sequencers revealed the entire sequence of both AAGGG and ACAGG repeat expansions at the nucleotide level of resolution. Clinical assessment and neuropathology results suggested that patients with ACAGG expansions have similar clinical features to previously reported patients with homozygous AAGGG expansions, although motor neuron involvement was more notable in patients with ACAGG expansions (even if one allele was involved). Furthermore, a later age of onset and slower clinical progression were implied in patients with ACAGG/AAGGG compound heterozygous expansions compared with either ACAGG or AAGGG homozygotes in our very limited cohort. Our study clearly shows the occurrence of repeat conformation heterogeneity, with possible different impacts on the affected nervous systems. The difference in disease onset and progression between compound heterozygotes and homozygotes might also be suspected but with very limited certainty due to the small sample number of cases in our study. Studies of additional patients are needed to confirm this.

Case Report: Takotsubo Cardiomyopathy in Bickerstaff Brainstem Encephalitis Triggered by COVID-19

Takotsubo cardiomyopathy (TCM) is a stress-induced cardiomyopathy triggered by critical illness including severe neurological disorders. However, an association between TCM and Bickerstaff brainstem encephalitis (BBE) has rarely been described. During the current coronavirus disease 2019 (COVID-19) pandemic, growing evidence indicates that COVID-19 often leads to various neurological disorders, but there are few reports of an association between COVID-19 and BBE. Here we report a case of TCM associated with BBE triggered by COVID-19, which subsided with immunotherapy for BBE. Both transthoracic echocardiography and electrocardiography led to early and accurate diagnosis of TCM. Sustained hemodynamic instability due to TCM was immediately lessened with immunotherapy whereas additional plasmapheresis and immunotherapy were required to treat BBE. This case indicates that BBE might follow COVID-19 and TCM should be considered when hemodynamic status remains unstable in a patient with BBE.

Therapeutic efficacy of heparin and direct factor Xa inhibitors in cancer-associated cryptogenic ischemic stroke with venous thromboembolism

BACKGROUND

Anticoagulation therapy, especially using heparin or recently developed oral direct factor Xa inhibitors (DiXals), is recommended as first-line treatment for cancer-related venous thromboembolism (VTE). However, the preventive efficacy of these anticoagulants for cancer-associated ischemic stroke is still unknown. We retrospectively investigated the efficacy of subcutaneous unfractionated heparin (UFH) and DiXals for preventing the recurrence of cancer-associated cryptogenic ischemic stroke with VTE.

METHODS

We retrospectively studied consecutive patients with cancer-associated cryptogenic ischemic stroke and comorbid VTE who received subcutaneous UFH or oral DiXaIs at 9 hospitals.

RESULT

Fifty-three patients (24 treated with UFH and 29 treated with DiXaIs) were enrolled. Of these, 47 demonstrated systemic metastasis (cancer stage IV). During 30-day follow-up after initiation of anticoagulation therapy, recurrent ischemic stroke was observed in only 1 patient (4%) in the UFH group and in 9 patients (31%) in the DiXal group. The incidence of major bleeding complications was similar between the 2 groups (4% and 10%, respectively). The cumulative risk of ischemic stroke recurrence within 30 days was lower with UFH than with DiXals (competing risk analysis, p = 0.008). In the DiXal group, patients who experienced recurrence showed significantly higher D-dimer levels than those without recurrence.

CONCLUSION

In patients with cancer-associated cryptogenic ischemic stroke and comorbid VTE, UFH demonstrated a lower rate of recurrent ischemic stroke than DiXaIs, and there were no differences in bleeding risk between the 2 treatments. D-dimer levels at stroke onset increased the risk of recurrence in the DiXal group but not in the UFH group.

Determining C5, C6 and C7 myotomes through comparative analyses of clinical, MRI and EMG findings in cervical radiculopathy

Objective

There are many myotome charts in the literature, but few studies have presented actual data to support their identification. We aimed to determine C5/C6/C7 myotomes based on clinical and EMG data of patients with cervical spondylotic radiculopathy (CSR) having a single-root lesion confirmed by MRI.

Methods

Medical Research Council (MRC) scores and EMG findings were retrospectively reviewed for patients enrolled from our EMG database.

Results

Enrolled were 25 patients (10 C5, 6 C6, and 9 C7 CSR). In C5 CSR, weakness or denervation potentials in EMG, or both, were observed in the deltoid (Del) and infraspinatus (Isp) muscles for all patients, and in the biceps brachii (BB) and brachioradialis (BR) muscles for 9/10 and 8/9 patients, respectively. In C6 CSR, weakness of the wrist extensor and/or denervation of the extensor carpi radialis longus (ECRL)/extensor carpi radialis brevis (ECRB), and those of the pronator teres (PT) were observed for all patients. Weakness was not observed for any other muscle in C6 CSR. Denervation potentials of ECRL were found in 5/8 and 3/5 patients with C5 and C6 CSR, respectively, whereas those of ECRB were found in 1/5, 6/6, and 2/5 patients with C5, C6 and C7 CSR, respectively. In C7 CSR, weakness/denervation of the triceps brachii (TB) and denervation potentials of the flexor carpi radialis (FCR) were observed for all patients. Denervation potentials in PT and weakness/denervation of the extensor digitorum (ED) were observed in 2/9 and 4/9 patients, respectively.

Conclusion

Suggested dominant myotomes are: C5 for the Del, Isp, BB, and BR, C5/6 for the ECRL, C6 > C7 for the ECRB and PT, and C7 for the TB and FCR.

Significance

The current study identified dominant myotomes that differ from the existing literature.

Hepatitis B Virus-related Vasculitic Neuropathy in an Inactive Virus Carrier Treated with Intravenous Immunoglobulin

We herein report a 33-year-old woman who was an asymptomatic hepatitis B virus (HBV) carrier and presented with distal muscle weakness in the legs and asymmetrical paresthesia in the distal extremities. A nerve biopsy specimen revealed fibrinoid necrosis associated with inflammatory infiltration in the perineural space, and deposition of hepatitis B core antigen and C4d complement was detected in the vascular endothelial cells as well as around the vessels. She was diagnosed with HBV-related vasculitic neuropathy and treated with intravenous immunoglobulin (IVIG). Her symptoms completely subsided after eight weeks. Vasculitic neuropathy rarely develops in the chronic inactive stages of HBV infection. This is the first report of an HBV-inactive carrier with vasculitic neuropathy successfully treated with IVIG.

A new method to define cutoff values in nerve conduction studies for carpal tunnel syndrome considering the presence of false-positive cases

BACKGROUND

Nerve conduction studies (NCS) are useful tools for diagnosing carpal tunnel syndrome (CTS). Establishing the normal values is the first step required for utilizing NCS for diagnosis. Previous epidemiological studies demonstrated the presence of fairly large number of false-positive subjects regarding NCS among control population, which has not been properly considered in past studies. This study proposed a new method to address this issue.

METHODS

Non-diabetic 144 CTS patients were retrospectively enrolled using clinically defined inclusion criteria. Controls consisted of 73 age-matched volunteers without hand symptoms. Six NCS parameters were evaluated including peak-latency difference by the thumb method (thumbdif) and that by the ring-finger method (ringdif). The Youden index of the receiver operator characteristic curve was used both to judge the sensitivity of a parameter and to identify false-positive cases that were thought to have subclinical median neuropathy at the wrist. The linear function of six parameters was constructed, and the coefficient for each parameter was variously changed.

RESULTS

When the Youden index took on the maximum value, seven control subjects (10%) were identified as false-positive and were excluded from the calculation of normal values. The most sensitive parameter before exclusion was thumbdif, whereas ringdif became the most sensitive after exclusion. The cut-off value for ringdif was 1.15 ms before exclusion, but was 0.37 ms after exclusion.

CONCLUSION

This method can be widely applied to solve the statistical problem when the gold standard is lacking, and the outside reference standard is not completely reliable.

Interaction of cathodal and anodal stimulations in nerve conduction studies

INTRODUCTION

In this work we investigated the interaction of cathodal and anodal stimulations in nerve conduction studies (NCSs).

METHODS

Subjects assessed consisted of 10 healthy volunteers. The ulnar nerve was stimulated at the wrist using 2 bipolar surface electrodes, simulating ordinary NCSs. We were able to independently change the stimulus current value at the distal cathode and the proximal anode.

RESULTS

The anodal stimulation became more difficult to elicit as the stimulus current at the cathode was increased, whereas the cathodal stimulation became more likely to occur as the stimulus current at the anode was increased.

DISCUSSION

During bipolar stimulation, the cathodal stimulation suppresses the anodal stimulation, whereas the anodal stimulation assists the cathodal stimulation. This explains the common observation in NCSs that the cathodal stimulation becomes difficult to elicit when the anode is moved away from the nerve. Muscle Nerve 59:713-716, 2019.

Fasciculation potentials and decremental responses in amyotrophic lateral sclerosis

OBJECTIVE

The positive correlation between fasciculation potentials (FPs) and decremental responses in repetitive nerve stimulation test (RNS) in amyotrophic lateral sclerosis (ALS) patients has been described based on only one past study. We revisited this issue.

METHODS

Subjects consisted of 30 prospectively-enrolled ALS patients on whom both needle EMG and RNS were conducted in the same trapezius muscle. Fasciculation potentials (FPs) were identified off-line from the restored 3-min signal. Firing rate of FPs (FR-FP) per minute was calculated from the total count of FPs of different origins. Correlations between FR-FP, decremental percentage (Decr%) and the amplitude of the initial compound muscle action potential (CMAPamp) in RNS were investigated.

RESULTS

There was no correlation between FR-FP and Decr% (r = 0.03) or between FR-FP and CMAPamp (r = 0.04). A significant negative correlation was observed between CMAPamp and Decr% (r = -0.56, P < .005).

CONCLUSION

FPs are not correlated with the decremental response in RNS.

SIGNIFICANCE

The underlying mechanism for FPs and decremental responses in ALS must be different and unrelated to each other.

Late Seizures after Stroke in Clinical Practice: The Prevalence of Non-convulsive Seizures

Objective The prevalence of the non-convulsive type of late seizure after stroke is unknown. The aim of the present study was to clarify the characteristics of late seizure in clinical practice, mainly focusing on the prevalence of non-convulsive seizure. Methods A total of 178 consecutive patients who were admitted and diagnosed with late seizure after stroke were retrospectively enrolled, and the data of 127 patients for whom the complete seizure was observed by a bystander were analyzed. Clinical information was obtained from the medical records and nursing notes. Results A non-convulsive seizure was observed in 37 patients (29%). A focal seizure and its secondary generalization accounted for 79% of the seizure types. Status epilepticus was observed in 60 patients (47%), including 11 patients (9%) without convulsion. The patients with non-convulsive seizures were significantly younger than those with convulsive seizures, but there were no other significant differences between the two groups with respect to sex, classification or the lesion of stroke. Conclusion There was a high rate of non-convulsive seizures in patients with late seizure after stroke. A non-convulsive seizure may be caused by any type or location of preceding stroke. More attention is needed in the differential diagnosis of neurological deterioration after stroke.

Investigation of anodal stimulation and its implications for F-wave examinations

INTRODUCTION

Recent studies have shown that stimulation occurs at the anode of stimulating electrodes instead of anodal block. This phenomenon may be a pitfall in F-wave examinations.

METHODS

Subjects included 10 healthy volunteers. Their ulnar nerve was stimulated at the wrist with the cathode placed distally. Antidromic impulses were evaluated using mixed nerve action potential (MNAP) at the elbow.

RESULTS

Anodal stimulation occurred for both sensory and motor fibers at 22 mm proximal to the anode, on average, which may theoretically shorten the F-wave latency by about 0.8 ms. Displacement of the anode away from the nerve made anodal stimulation less likely. In contrast, displacement of the cathode away from the nerve lowered the threshold for anodal stimulation, a newly found interaction between cathode and anode.

CONCLUSIONS

In this work we identified detailed features of anodal stimulation and potential influence on F-wave examinations. Muscle Nerve 56: 51-56, 2017.

Primary aldosteronism in patients with acute stroke: prevalence and diagnosis during initial hospitalization

Background

Hypertension is the prime risk factor for stroke, and primary aldosteronism (PA) is the most common cause of secondary hypertension. The prevalence of PA in stroke patients has never been reported. The aim of this study was to elucidate the prevalence of PA.

Methods

A total of 427 consecutive patients with acute stroke were prospectively enrolled for this study. The screening tests were performed at the initial visit and a week after admission by measuring plasma aldosterone concentration and plasma renin activity. The rapid adrenocorticotropic hormone (ACTH) test was performed as the confirmatory test when both screening tests were positive. The primary endpoint was a final diagnosis of PA.

Results

The sensitivity of the dual screening system for the diagnosis of PA was 88.2 %, and PA was finally diagnosed in 4.0 % of acute stroke patients and in 4.9 % of stroke patients with a history of hypertension. Patients with PA were less likely to be male and have diabetes, and they had higher blood pressure at the initial visit, lower potassium concentration, and more intracerebral hemorrhage. The rapid ACTH test was performed safely even in acute stroke patients.

Conclusions

The prevalence of PA is not low among acute stroke patients. Efficient screening of PA should be performed particularly for patients with risk factors.

Trial registration

UMIN-CTR; UMIN000011021. Trial registration date: June 23, 2013 (retrospectively registered).

[Aseptic meningitis in a patient with cerebrospinal fluid anti-agalactosyl IgG antibody-positive preclinical rheumatoid arthritis: a case report]

A 69-year-old woman presented with non-fluent aphasia, ideomotor apraxia, right hemiparesis and convulsion. Her medical history was unremarkable, and she had not suffered from arthritis. DWI and FLAIR image of brain MRI showed hyperintensities in the subarachnoid space along the left frontal and both parietal lobes, and these lesions were associated with gadolinium enhancement. The levels of serum anti-cyclic citrullinated peptide antibody, anti-agalactosyl IgG antibody and matrix metalloproteinase-3 were elevated. The results of blood cultures were negative. Cerebrospinal fluid (CSF) analysis revealed monocytic pleocytosis and negative findings for infection or malignancy. The level of anti-agalactosyl IgG antibody in CSF was elevated. The antibody index (AI) of anti-agalactosyl IgG antibody (the ratio between the CSF/serum quotient for IgG antibodies, and the CSF/serum quotient for total IgG; normal value of AI < 1.3) showed considerably high value of 8.4, indicating the intrathecal-specific antibody synthesis. As a result, the pathogenesis of her disease was consistent with rheumatoid meningitis despite lack of arthritis. After intravenous administration of methylprednisolone, her symptoms, the level of anti-agalactosyl IgG antibody in CSF, and the MRI findings were ameliorated. Anti-agalactosyl IgG antibody in the CSF was a helpful biomarker in diagnosis and assessment of the severity of rheumatoid meningitis.

High-resolution magnetic resonance imaging findings of basilar artery plaque in a patient with branch atheromatous disease: a case report

Introduction

Intracranial branch atheromatous disease is a type of ischemic stroke that is caused by narrowing or occlusion of the orifice of the penetrating artery by atheromatous plaque. Pontine branch atheromatous disease is usually diagnosed using indirect findings such as the extension of a lesion to the basal surface of the pons because of the difficulty of demonstrating plaque in the basilar artery.

Case presentation

A 72-year-old Japanese man developed sudden dysarthria and left hemiparesis, and his symptoms deteriorated thereafter. Brain magnetic resonance imaging revealed an acute infarction in the territory of the right paramedian pontine artery extending to the basal surface. Non-contrast-enhanced three-dimensional fast spin-echo T1 imaging with variable flip angles and three-dimensional fast imaging with steady-state acquisition revealed a plaque in the dorsal wall of the basilar artery that spread to the origin of the paramedian pontine artery that branched toward the infarction. Although antithrombotic agents were started, the left hemiparesis got worse and became flaccid on the following day.

Conclusions

This is the first report to confirm the pathological basis of branch atheromatous disease by three-dimensional images using the new modalities of 3-Tesla magnetic resonance imaging. The use of these techniques will foster better understanding of the clinicopathological mechanisms of branch atheromatous disease.

[A 68 year-old man presenting ideomotor apraxia and incomplete Gerstmann syndrome with multiple cystic lesions in the left hemisphere]

A 68-year-old man was referred to our hospital with tension-type headaches and a 1-year history of dementia. On neurologic examination, he had ideomotor apraxia and incomplete Gerstmann syndrome that was characterized by acalculia, agraphia, and finger agnosia. On imaging, multiple cystic lesions reported as "unusually dilated perivascular spaces" were observed along the medullary arteries in the left hemisphere; some of them had adjacent hyperintense areas in fluid attenuated inversion recovery images. We assumed that the multiple cystic lesions caused his higher cerebral dysfunction, because ideomotor apraxia and Gerstmann syndrome are usually indicative of a left parietal lobe lesion. MR spectroscopy in the lesion site revealed increased lactate. On MR angiography, the left middle cerebral artery and the left posterior cerebral artery were poorly visualized without localized stenosis. Technetium-99 bicisate single-photon emission computed tomography showed severely decreased cerebral blood flow in the left hemisphere. Electroencephalography showed slow waves in the left hemisphere.

Vascular corticobasal syndrome caused by unilateral internal carotid artery occlusion

A 65-year-old man developed progressive worsening of right-sided limb-kinetic apraxia and extrapyramidal dysfunction. His left internal carotid artery was found to be occluded, and there was general atrophy and severely decreased cerebral blood flow in the left hemisphere. He had experienced an acute infarction in the left watershed area before superficial temporal artery to middle cerebral artery bypass surgery. After surgery, the cerebral blood flow in the left hemisphere was remarkably improved. Unilateral internal carotid artery occlusion may result in clinical manifestations similar to corticobasal degeneration.

[A case of spinocerebellar ataxia type 2 presenting with a clinical course similar to spastic paraparesis]

We report a 50-year-old woman with an unremarkable birth and developmental history, and with no family history of neurological disorders. The patient had a 6-year history of progressive cervical dystonia, oral dyskinesia, and hyperreflexia. She was initially considered to have spastic paraparesis of unknown cause. Because brain MRI showed mild atrophy of the cerebellar vermis, genetic analysis for spinocerebellar ataxia types 1, 2, 3, 6, 7, 8, 12, and 17, and dentatorubral-pallidoluysian atrophy was performed. The results revealed an abnormal expansion of CAG repeats (38 repeats) in one allele of ATXN2, and the patient was diagnosed with spinocerebellar ataxia type 2 (SCA2). She had no major clinical features of SCA2 such as cerebellar ataxia, slow saccade, or hyporeflexia. Recent reports have shown the CAG repeat expansion in ATXN2 to be detected in patients with familial L-dopa-responsive parkinsonism. The present case suggests that CAG repeat expansion in ATXN2 may be detected in some patients with spastic paraparesis, and that wide variations of clinical manifestations exist in SCA2.

Siblings with the adult-onset slowly progressive type of pantothenate kinase-associated neurodegeneration and a novel mutation, Ile346Ser, in PANK2: clinical features and (99m)Tc-ECD brain perfusion SPECT findings

Pantothenate kinase-associated neurodegeneration (PKAN), formerly known as Hallervorden-Spatz syndrome (HSS), is an autosomal recessive neurodegenerative disorder characterized by iron accumulation in the brain. Mutations in the pantothenate kinase 2 (PANK2) gene are known to be responsible for PKAN. Several studies have revealed correlations between clinical phenotypes and particular PANK2 mutations. The adult-onset slowly progressive type of PKAN with PANK2 mutations is very rare. In this report, we describe siblings with the adult-onset slowly progressive type of PKAN with a novel mutation, Ile346Ser, in PANK2. The siblings had the same mutation in PANK2 and had common clinical signs such as misalignment of teeth, a high arched palate, hollow feet, a slight cognitive decline, and an apparent executive dysfunction, although they showed different patterns of movement disorders. Thus, even if PKAN patients have identical mutations, it is likely that they will present with different types of movement disorders. Brain perfusion single photon emission computed tomography in both patients showed decreased regional cerebral blood flow in the bilateral frontoparietal lobes, the globus pallidus, the striatum, and around the ventriculus quartus. Cardiac uptake of [(123)I] meta-iodobenzylguanidine was normal in both patients. Analysis of genotype-phenotype correlations and the elucidation of mutational effects on pantothenate kinase 2 function, expression, and structure are important for understanding the mechanisms of PKAN.

Frequent reduced expression of alpha-1B-adrenergic receptor caused by aberrant promoter methylation in gastric cancers

Recent studies have suggested that epigenetic inactivation of tumour-related genes by promoter methylation participates in the development of gastric cancer. We newly identified the frequently aberrant promoter methylation of alpha-1B-adrenergic receptor (ADRA1B) in colorectal cancer by methylation-sensitive representational difference analysis (MS-RDA) and examined the methylation status of the ADRA1B promoter in 34 paired samples of colorectal cancer and surrounding epithelial tissue, and 34 paired samples of gastric cancer and surrounding epithelial tissue. In colorectal cancers, only four of 34 (11.8%) tumours showed ADRA1B promoter methylation. In contrast, ADRA1B promoter methylation was detected in 24 of 34 (70.6%) gastric cancers and in 14 of 34 (41.2%) surrounding epithelial tissues. The frequency of ADRA1B promoter methylation was higher in gastric epithelial tissues with intestinal metaplasia (41.6%) than in those without intestinal metaplasia (25.0%). Reverse transcription–PCR detected reduced ADRA1B expression in 12 of 18 (66.7%) gastric cancers, and its promoter methylation was detected in 11 of these 12 (91.7%) gastric cancers with reduced ADRA1B expression. Thus, ADRA1B promoter is frequently methylated in gastric cancer. Our results suggest that the ADRA1B gene is an important tumour-related gene frequently involved in the development and progression of gastric cancer.