Cerebral Microbleeds, Cerebrospinal Fluid, and Neuroimaging Markers in Clinical Subtypes of Alzheimer's Disease.

Lobar cerebral microbleeds (CMBs) in Alzheimer's disease (AD) are associated with cerebral amyloid angiopathy (CAA) due to vascular amyloid beta (Aß) deposits. However, the relationship between lobar CMBs and clinical subtypes of AD remains unknown. Here, we enrolled patients with early- and late-onset amnestic dominant AD, logopenic variant of primary progressive aphasia (lvPPA) and posterior cortical atrophy (PCA) who were compatible with the AD criteria. We then examined the levels of cerebrospinal fluid (CSF) biomarkers [Aß1-42, Aß1-40, Aß1-38, phosphorylated tau 181 (P-Tau), total tau (T-Tau), neurofilament light chain (NFL), and chitinase 3-like 1 protein (YKL-40)], analyzed the number and localization of CMBs, and measured the cerebral blood flow (CBF) volume by 99mTc-ethyl cysteinate dimer single photon emission computerized tomography (99mTc ECD-SPECT), as well as the mean cortical standard uptake value ratio by 11C-labeled Pittsburgh Compound B-positron emission tomography (11C PiB-PET). Lobar CMBs in lvPPA were distributed in the temporal, frontal, and parietal lobes with the left side predominance, while the CBF volume in lvPPA significantly decreased in the left temporal area, where the number of lobar CMBs and the CBF volumes showed a significant inversely correlation. The CSF levels of NFL in lvPPA were significantly higher compared to the other AD subtypes and non-demented subjects. The numbers of lobar CMBs significantly increased the CSF levels of NFL in the total AD patients, additionally, among AD subtypes, the CSF levels of NFL in lvPPA predominantly were higher by increasing number of lobar CMBs. On the other hand, the CSF levels of Aß1-38, Aß1-40, Aß1-42, P-Tau, and T-Tau were lower by increasing number of lobar CMBs in the total AD patients. These findings may suggest that aberrant brain hypoperfusion in lvPPA was derived from the brain atrophy due to neurodegeneration, and possibly may involve the aberrant microcirculation causing by lobar CMBs and cerebrovascular injuries, with the left side dominance, consequently leading to a clinical phenotype of logopenic variant.

Noncoding CGG repeat expansions in neuronal intranuclear inclusion disease, oculopharyngodistal myopathy and an overlapping disease.

Noncoding repeat expansions cause various neuromuscular diseases, including myotonic dystrophies, fragile X tremor/ataxia syndrome, some spinocerebellar ataxias, amyotrophic lateral sclerosis and benign adult familial myoclonic epilepsies. Inspired by the striking similarities in the clinical and neuroimaging findings between neuronal intranuclear inclusion disease (NIID) and fragile X tremor/ataxia syndrome caused by noncoding CGG repeat expansions in FMR1, we directly searched for repeat expansion mutations and identified noncoding CGG repeat expansions in NBPF19 (NOTCH2NLC) as the causative mutations for NIID. Further prompted by the similarities in the clinical and neuroimaging findings with NIID, we identified similar noncoding CGG repeat expansions in two other diseases: oculopharyngeal myopathy with leukoencephalopathy and oculopharyngodistal myopathy, in LOC642361/NUTM2B-AS1 and LRP12, respectively. These findings expand our knowledge of the clinical spectra of diseases caused by expansions of the same repeat motif, and further highlight how directly searching for expanded repeats can help identify mutations underlying diseases.

Oral Immunization with Soybean Storage Protein Containing Amyloid-ß 4-10 Prevents Spatial Learning Decline.

Amyloid-ß (Aß) plays a central role in the pathogenesis of Alzheimer's disease (AD). Because AD pathologies begin two decades before the onset of dementia, prevention of Aß amyloidosis has been proposed as a mean to block the pathological cascade. Here, we generate a transgenic plant-based vaccine, a soybean storage protein containing Aß4-10, named Aß+, for oral Aß immunization. One mg of Aß+ or control protein (Aß-) was administered to TgCRND8 mice once a week from 9 weeks up to 58 weeks. Aß+ immunization raised both anti-Aß antibodies and cellular immune responses. Spatial learning decline was prevented in the Aß+ immunized group in an extended reference memory version of Morris water maze test from 21 to 57 weeks. In Tris-buffered saline (TBS), sodium dodecyl sulfate (SDS), and formic acid (FA) serial extractions, all sets of Aß species from Aß monomer, low to high molecular weight Aß oligomers, and Aß smears had different solubility in TgCRND8 brains. Aß oligomers decreased in TBS fractions, corresponding to an increase in high molecular weight Aß oligomers in SDS extracts and Aß smears in FA fraction of the Aß+ treated group. There was significant inhibition of histological Aß burden, especially in diffuse plaques, and suppression of microglial inflammation. Processing of amyloid-ß protein precursor was not different between Aß+ and Aß- groups. No evidence of amyloid-related inflammatory angiopathy was observed. Thus, Aß+ oral immunization could be a promising, cheap, and long-term safe disease-modifying therapy to prevent the pathological process in AD.

Cerebrospinal Fluid and Plasma Biomarkers in Neurodegenerative Diseases.

Cerebrospinal fluid (CSF) amyloid-ß (Aß)42 and tau are biomarkers for Alzheimer's disease (AD); however, the effects of other neurodegenerative processes on these biomarkers remain unclear. We measured Aß40, Aß42, total tau, phosphorylated-tau, and α-synuclein in CSF and plasma using matched samples from various neurodegenerative diseases to expand our basic knowledge on these biomarkers and their practical applications. A total of 213 CSF and 183 plasma samples were analyzed from cognitively unimpaired subjects, and patients with Alzheimer's disease dementia (ADD), mild cognitive impairment (MCI), non-AD dementias, and other neurological diseases. The CSF/plasma ratios of Aß40 and Aß42 were approximately 25:1. Aß40/42 ratios in CSF and plasma were both 10:1. The CSF total tau/P181tau ratio was 6:1. The CSF/plasma α-synuclein ratio was 1:65. Significantly decreased Aß42 levels and an increased Aß40/42 ratio in CSF in ADD/MCI suggested that these relationships were specifically altered in AD. Increased total tau levels in ADD/MCI, encephalopathy, and multiple system atrophy, and increased P181tau in ADD/MCI indicated that these biomarkers corresponded to neurodegeneration and tauopathy, respectively. Although CSF α-synuclein levels were increased in ADD/MCI, there was no merit in measuring α-synuclein in CSF or plasma as a biomarker. The combination of biomarkers by the Aß40/42 ratio×p181tau reflected specific changes due to the AD pathology in ADD/MCI. Thus, CSF Aß40, Aß42, p181tau, and tau were identified as biomarkers for aggregated Aß associated state (A), aggregated tau associated state (T), and neurodegeneration state (N) pathologies in AD based on the NIA-AA criteria. Overlaps in these biomarkers need to be considered in clinical practice for differential diagnoses of neurodegenerative diseases.

Dentatorubral-pallidoluysian atrophy (DRPLA) with a small ganglioglioma component containing neurofibrillary tangles and polyglutamine aggregation.

Dentatorubral-pallidoluysian atrophy (DRPLA), one of the polyglutamine diseases, has not been reported in combination with ganglioglioma (GG). Herein, we report an autopsy case of a 72-year-old man with DRPLA with a small GG component harboring neurofibrillary tangles (NFTs) and polyglutamine aggregates. NFTs, cytoplasmic accumulations of hyper-phosphorylated tau, are mainly observed in Alzheimer's disease (AD) and other tau-associated neurodegenerative disorders. NFTs can also be present in normal aging, and are occasionally observed in low-grade central nervous system (CNS) neoplasms such as GG. In the present case, whole brain examination demonstrated widespread deposition of polyglutamine aggregates, including GG, whereas NFTs were restricted to the GG component. In addition, no other AD or aging-related neuropathological structures were detected throughout the CNS. These findings may provide us with clues to elucidate the pathogenetic mechanisms that neuronal neoplasms may have to develop NFTs regardless of aging, and that polyglutamine may accumulate in neoplastic neurons in polyglutamine disease.

A Case of Optic Neuritis Concomitant with Pituitary Tumor During Pregnancy.

BACKGROUND: Optic neuritis (ON) is unilateral painful optic nerve inflammation in a young healthy female diagnosed by excluding glaucoma. ON onset during pregnancy is rare, with only 2 cases reported to date. CASE DESCRIPTION: A 35-year-old previously healthy parous woman who was pregnant with her second child suffered rapidly progressive visual acuity loss. Magnetic resonance imaging (MRI) revealed a pituitary tumor. Emergency surgery was performed for optic nerve compression; however, her visual impairment worsened. Postoperative diffusion-weighted MRI showed high intensity in the bilateral optic nerves, and ON was diagnosed. Administration of methylprednisolone was effective, and her visual acuity recovered over 6 months. CONCLUSIONS: Associated pituitary macroadenoma complicated the true diagnosis of ON, because contrast medium cannot be used in pregnant women. The diffusion-weighted MRI findings were useful for diagnosing this complex clinical condition.

CSF levels of Aß1-38/Aß1-40/Aß1-42 and (11)C PiB-PET studies in three clinical variants of primary progressive aphasia and Alzheimer's disease.

Primary progressive aphasia (PPA) is a cognitive syndrome characterized by progressive and isolated language impairments due to neurodegenerative diseases. Recently, an international group of experts published a Consensus Classification of the three PPA clinical variants (naPPA, svPPA and lvPPA). We analyzed 24 patients with PPA by cognitive functions, neuroimaging (MRI, (99 m)Tc ECD-SPECT, (11)C PiB-PET and FDG-PET) and cerebrospinal fluid (CSF) analysis (ptau-181, Aß1-42, Aß1-40 and Aß1-38), to elucidate relationships between neuroimaging studies and biochemical findings in the three PPA clinical variants. Cognitive and speech functions were measured by mini-mental state examination and standard language test of aphasia. The patients with lvPPA showed significant decreases in CSF Aß1-42 and ratios of Aß1-42/Aß1-40 and Aß1-42/Aß1-38, and significant increases in CSF ptau-181 and ratios of ptau-181/Aß1-42 and ptau-181/Aß1-38; these findings were similar to those of patients with Alzheimer's disease (AD). We observed a higher frequency of the ApoE ε4 allele in the lvPPA patients relative to the two other PPA variants. In (11)C PiB-PET of lvPPA patients, PiB positive findings were detected in cortices of frontal, temporal and parietal lobes and the posterior cingulate, where massive Aß may accumulate due to AD. Our results of AD-CSF markers including Aß1-38 and (11)C PiB-PET in the lvPPA patients demonstrate a common pathological mechanism with the occurrence of AD.

Lack of genetic association between TREM2 and late-onset Alzheimer's disease in a Japanese population.

Rare non-synonymous variants of TREM2 have recently been shown to be associated with Alzheimer's disease (AD) in Caucasians. We here conducted a replication study using a well-characterized Japanese sample set, comprising 2,190 late-onset AD (LOAD) cases and 2,498 controls. We genotyped 10 non-synonymous variants (Q33X, Y38C, R47H, T66M, N68K, D87N, T96K, R98W, H157Y, and L211P) of TREM2 reported by Guerreiro et al. (2013) by means of the TaqMan and dideoxy sequencing methods. Only three variants, R47H, H157Y, and L211P, were polymorphic (range of minor allele frequency [MAF], 0.0002-0.0059); however, no significant association with LOAD was observed in these variants. Considering low MAF of variants examined and our study sample size, further genetic analysis with a larger sample set is needed to firmly evaluate whether or not TREM2 is associated with LOAD in Japanese.

Haploinsufficiency of CSF-1R and clinicopathologic characterization in patients with HDLS.

OBJECTIVE: To clarify the genetic, clinicopathologic, and neuroimaging characteristics of patients with hereditary diffuse leukoencephalopathy with spheroids (HDLS) with the colony stimulating factor 1 receptor (CSF-1R) mutation. METHODS: We performed molecular genetic analysis of CSF-1R in patients with HDLS. Detailed clinical and neuroimaging findings were retrospectively investigated. Five patients were examined neuropathologically. RESULTS: We found 6 different CSF-1R mutations in 7 index patients from unrelated Japanese families. The CSF-1R mutations included 3 novel mutations and 1 known missense mutation at evolutionarily conserved amino acids, and 1 novel splice-site mutation. We identified a novel frameshift mutation. Reverse transcription PCR analysis revealed that the frameshift mutation causes nonsense-mediated mRNA decay by generating a premature stop codon, suggesting that haploinsufficiency of CSF-1R is sufficient to cause HDLS. Western blot analysis revealed that the expression level of CSF-1R in the brain from the patients was lower than from control subjects. The characteristic MRI findings were the involvement of the white matter and thinning of the corpus callosum with signal alteration, and sequential analysis revealed that the white matter lesions and cerebral atrophy relentlessly progressed with disease duration. Spotty calcifications in the white matter were frequently observed by CT. Neuropathologic analysis revealed that microglia in the brains of the patients demonstrated distinct morphology and distribution. CONCLUSIONS: These findings suggest that patients with HDLS, irrespective of mutation type in CSF-1R, show characteristic clinical and neuroimaging features, and that perturbation of CSF-1R signaling by haploinsufficiency may play a role in microglial dysfunction leading to the pathogenesis of HDLS.

Cerebrospinal fluid levels of phosphorylated tau and Aß1-38/Aß1-40/Aß1-42 in Alzheimer's disease with PS1 mutations.

We studied seven cases of Alzheimer's disease (AD). Six of the patients had presenilin 1 (PS1) mutations (PS1AD). Three novel PS1 mutations (T99A, H131R and L219R) and three other missense mutations (M233L, H163R and V272A) were found in the PS1AD group. We measured the levels of phosphorylated tau (ptau-181, ptau-199) and Aß (Aß1-42, Aß1-40 and Aß1-38) in the cerebrospinal fluid (CSF) of PS1AD patients, early-onset sporadic AD (EOSAD), late-onset sporadic AD (LOSAD) and non-demented subjects (ND). The CSF levels of Aß1-42 in the three AD groups were significantly lower than those of the ND group (p < 0.0001). CSF levels of Aß1-42 in the PS1AD group were significantly lower than those in the two sporadic AD groups. The Aß1-40 and Aß1-38 levels in the CSF of the PS1AD group were significantly lower than those of the three other groups (p < 0.0001, respectively). The levels of Aß1-40, Aß1-38 and Aß1-42 in the CSF of the PS1AD group remained lower than those of the ND group for 4 years. Not only CSF Aß1-42, but also Aß1-40 and Aß1-38 decreased in the advanced stages of PS1AD.

SORL1 is genetically associated with late-onset Alzheimer's disease in Japanese, Koreans and Caucasians.

To discover susceptibility genes of late-onset Alzheimer's disease (LOAD), we conducted a 3-stage genome-wide association study (GWAS) using three populations: Japanese from the Japanese Genetic Consortium for Alzheimer Disease (JGSCAD), Koreans, and Caucasians from the Alzheimer Disease Genetic Consortium (ADGC). In Stage 1, we evaluated data for 5,877,918 genotyped and imputed SNPs in Japanese cases (n = 1,008) and controls (n = 1,016). Genome-wide significance was observed with 12 SNPs in the APOE region. Seven SNPs from other distinct regions with p-values <2×10(-5) were genotyped in a second Japanese sample (885 cases, 985 controls), and evidence of association was confirmed for one SORL1 SNP (rs3781834, P = 7.33×10(-7) in the combined sample). Subsequent analysis combining results for several SORL1 SNPs in the Japanese, Korean (339 cases, 1,129 controls) and Caucasians (11,840 AD cases, 10,931 controls) revealed genome wide significance with rs11218343 (P = 1.77×10(-9)) and rs3781834 (P = 1.04×10(-8)). SNPs in previously established AD loci in Caucasians showed strong evidence of association in Japanese including rs3851179 near PICALM (P = 1.71×10(-5)) and rs744373 near BIN1 (P = 1.39×10(-4)). The associated allele for each of these SNPs was the same as in Caucasians. These data demonstrate for the first time genome-wide significance of LOAD with SORL1 and confirm the role of other known loci for LOAD in Japanese. Our study highlights the importance of examining associations in multiple ethnic populations.

Phagocytized corpora amylacea as a histological hallmark of astrocytic injury in neuromyelitis optica.

Neuromyelitis optica (NMO) is an inflammatory demyelinating and necrotizing disorder of the CNS that mainly affects the optic nerve and spinal cord. The etiology is still uncertain; however, the discovery of serum anti-aquaporin-4 (AQP4) autoantibody is becoming the center of attention, and a new hypothesis is emerging that NMO is essentially astrocytopathy provoked by this autoantibody. In this study, we focused on corpora amylacea (CA), glycoproteinaceous inclusions in astrocytic processes. We examined 57 lesions in nine cases of NMO spectrum disorder, and demonstrated that CA were phagocytized by macrophages in 42 lesions (74%) of eight cases, while phagocytized figures were not seen in unaffected areas. Phagocytized CA were frequently encountered in early-phase lesions still retaining myelin structures, while fewer or none were found in chronic destructive lesions. Moreover, phagocytized CA were significantly smaller in diameter than intact ones, and CA were decreased or absent in most lesions assessed. These findings suggest the following pathophysiological process: the astrocytes are affected at an early phase in NMO, CA are expelled from the astrocytes and phagocytized by macrophages finally leading to clearance. A phagocytized figure and subsequent loss of CA can be a histological hallmark of astrocytic injury of NMO.

Yamaguchi fox-pigeon imitation test (YFPIT) for dementia in clinical practice.

BACKGROUND: In out-patient clinics, having simple procedures to check for signs of dementia is invaluable. In the present study, we evaluated the imitation of hand gestures to detect visuomotor deficits in dementia in clinical practice. METHODS: In all, 1219 subjects were enrolled in the present study, including 497 with Alzheimer's disease (AD), 98 with dementia with Lewy bodies (DLB), 71 with other types of dementia diseases, 175 with a Clinical Dementia Rating (CDR) of 0.5, and 378 normal controls. All subjects were aged 65 years or older. Subjects were recruited from 10 clinics and two communities. Visuomotor function was evaluated by the Yamaguchi fox-pigeon imitation test (YFPIT), which consists of a simple one-handed sign for 'fox' and a complex two-handed sign for 'pigeon', a rapid, game-like test with low psychological burden. RESULTS: The success rate (successful/total) for imitating the 'pigeon' hand gesture was reduced as the severity of the dementia increased: 85.7% in normal controls, 60.6% in CDR 0.5 (mild cognitive impairment), 39.2% in CDR 1 (mild dementia), 21.2% in CDR 2 (moderate dementia), and 5.7% in CDR 3 (severe dementia). The success rate for imitating the 'pigeon' hand gesture was higher in patients with DLB than AD within the CDR 1 group (51.2% vs 35.4%, respectively), but lower for patients with DLB than AD within the CDR 2 group (12.5% vs 24.4%, respectively). The success of imitating the hand gesture for 'fox' was similar for patients with AD and DLB. Of those subjects who failed to imitate the hand gesture for 'pigeon', 49.5% of those with AD showed the palm-palm pattern (both palms facing outward), suggesting deficits of perspective conversion from the first-person to the third-person. Conversely, 52.8% of patients with DLB showed a dorsum-dorsum pattern (both dorsa facing outwards), suggesting deterioration of visual attention and recognition. CONCLUSION: In conclusion, the YFPIT is a useful test to detect visuomotor deficits in dementia that can differentiate between AD and DLB.

Quantification of cystatin C in cerebrospinal fluid from various neurological disorders and correlation with G73A polymorphism in CST3.

Cystatin C (CC) is a cysteine protease inhibitor abundantly expressed in the central nervous system. Bunina bodies, small eosinophilic intraneuronal inclusions, are stain positive for CC and are the most specific histological hallmark of amyotrophic lateral sclerosis (ALS). In this study, employing a latex turbidimetric immunoassay, levels of CC in cerebrospinal fluid (CSF) were quantified in 130 age-matched individuals with either a neurological disorder [ALS, Alzheimer's disease (AD), Parkinson's disease (PD), tauopathy (TP), multiple system atrophy (MSA), chronic inflammatory demyelinating polyneuropathy (CIDP)] or no known neurological condition (normal control, NC). The CC level in CSF was found to be correlated with the age during the investigation but not the protein concentration. There was no difference in CC levels between NC and ALS or CIDP cases, whereas CC levels were significantly lower in MSA compared with NC. Of the 130 cases, 96 were genotyped, and G/A or A/A polymorphism at +73 within the CST3 gene was found in 28 individuals. The CC level was significantly lower in the combined group of G/A and A/A genotypes compared with G/G. The present data demonstrate that the level of CC in CSF should not be considered as a biomarker of ALS, but there is a correlation between CC levels and the CST3 genotype.

Extensive screening system using suspension array technology to detect mitochondrial DNA point mutations.

We established an extensive and rapid system using suspension array to detect 61 representative mitochondrial DNA (mtDNA) heteroplasmic or homoplasmic point mutations (29 for Series A and 32 for Series B) in 22 genes: 1 each in MT-RNR1, -TV, -ND1, -TQ, -TW, -TC, and -TH genes; 2 each in MT-TN, -TG, -ND4, -TL2, -TE, and -CYB genes; 3 each in MT-ATP6, -ND3, and -ND5 genes; 4 each in MT-CO1 and -TK genes; 5 each in MT-TI, -TS1, and -ND6 genes; and 10 in the MT-TL1 gene. We carefully selected 5'-biotinylated primers and pooled primers for use in two sets of multiplex-PCR amplifications. To detect both mutant and wild-type mtDNA, even when polymorphisms were present near the target mutation sites, we designed specific oligonucleotide probes. By using the mtDNA point mutation detection system of Series A (29 mutations) and Series B (32 mutations), we screened a total of 3103 mutant sites in 107 DNA samples for Series A and 13,101 mutant sites in 397 DNA samples for Series B. We succeeded in determining 99.4% (Series A) and 99.6% (Series B) of the targeted mutant sites by use of the system. The 22 samples with the m.3243A>G heteroplasmic mutation revealed positive signals with both mutant- and wild-type-specific probes in this detection system with a detection limit of approximately 2%. This genetic screening platform is useful to reach a definitive diagnosis for mitochondrial diseases.

Motor impairment and aberrant production of neurochemicals in human alpha-synuclein A30P+A53T transgenic mice with alpha-synuclein pathology.

Missense point mutations, duplication and triplication in the alpha-synuclein (alphaSYN) gene have been identified in familial Parkinson's disease (PD). Familial and sporadic PD show common pathological features of alphaSYN pathologies, e.g., Lewy bodies (LBs) and Lewy neurites (LNs), and a loss of dopaminergic neurons in the substantia nigra that leads to motor disturbances. To elucidate the mechanism of alphaSYN pathologies, we generated TgalphaSYN transgenic mice overexpressing human alphaSYN with double mutations in A30P and A53T. Human alphaSYN accumulated widely in neurons, processes and aberrant neuronal inclusion bodies. Sarcosyl-insoluble alphaSYN, as well as phosphorylated, ubiquitinated and nitrated alphaSYN, was accumulated in the brains. Significantly decreased levels of dopamine (DA) were recognized in the striatum. Motor impairment was revealed in a rotarod test. Thus, TgalphaSYN is a useful model for analyzing the pathological cascade from aggregated alphaSYN to motor disturbance, and may be useful for drug trials.

Transthyretin accelerates vascular Abeta deposition in a mouse model of Alzheimer's disease.

Transthyretin (TTR) binds amyloid-beta (Abeta) and prevents Abeta fibril formation in vitro. It was reported that the lack of neurodegeneration in a transgenic mouse model of Alzheimer's disease (AD) (Tg2576 mouse) was associated with increased TTR level in the hippocampus, and that chronic infusion of anti-TTR antibody into the hippocampus of Tg2576 mice led to increased local Abeta deposits, tau hyperphosphorylation and apoptosis. TTR is, therefore, speculated to prevent Abeta pathology in AD. However, a role for TTR in Abeta deposition is not yet known. To investigate the relationship between TTR and Abeta deposition, we generated a mouse line carrying a null mutation at the endogenous TTR locus and the human mutant amyloid precursor protein cDNA responsible for familial AD (Tg2576/TTR(-/-) mouse) by crossing Tg2576 mice with TTR-deficient mice. We asked whether Abeta deposition was accelerated in Tg2576/TTR(-/-) mice relative to the heterozygous mutant Tg2576 (Tg2576/TTR(+/-)) mice. Contrary to our expectations, the degree of total and vascular Abeta burdens in the aged Tg2576/TTR(-/-) mice was significantly reduced relative to the age-matched Tg2576/TTR(+/-) mice. Our experiments present, for the first time, compelling evidence that TTR does not suppress but rather accelerates vascular Abeta deposition in the mouse model of AD.

Differentiation of PA from early PSP with different patterns of symptoms and CBF reduction.

OBJECTIVE: To clarify the features of pure akinesia (PA) and progressive supranuclear palsy (PSP) in the early stage of disease. METHODS: We investigated 15 PA and 41 PSP patients' clinical and radiologic features including head MRI, ethyl cysteinate dimmer-single photon emission-computed tomography (ECD-SPECT) and iodine-123 meta-iodobenzyl guanidine (123I-MIBG) myocardial scintigraphy. In ECD-SPECT study, cerebral blood flow (CBF) reduction was quantitatively expressed as Z-score, and that in the frontal lobe was evaluated. RESULTS: Many PSP patients claimed falls as the initial symptom but no PA patients did. Eye movement, as well as optokinetic nystagmus elicitation, was more frequently disturbed in PSP. Dementia, dysarthria and rigidity were also more frequent in PSP than in PA. Midbrain tegmentum atrophy in head MRI was more frequently observed in PSP. CBF in the frontal lobe, especially in the frontal eye field, was significantly lower in PSP than in PA. MIBG myocardial scintigraphy showed no difference between two groups. DISCUSSION: PA and PSP show distinct symptoms from the early stage, indicating that they are distinct disorders. The occurrence of falls and eye movement disturbance, as well as CBF reduction at the frontal eye field, is very important for distinguishing these disorders.