Multiple Sclerosis: Shall We Target CD33?

BACKGROUND

Multiple sclerosis (MS) is a chronic disease of the central nervous system (CNS). Myeloid lineage cells (microglia and macrophages) may participate in the pathogenic mechanisms leading to MS. CD33 is a transmembrane receptor, mainly expressed by myeloid lineage cells. CD33 rs3865444 is a promoter variant previously associated with Alzheimer's disease, whose role in MS remains obscure.

OBJECTIVE

To assess the role of CD33 rs3865444 in MS risk.

METHODS

We genotyped 1396 patients with MS and 400 healthy controls for the presence of the CD33 rs3865444 variant. Odds ratios (ORs) with the respective 95% confidence intervals (CIs), were calculated with the SNPStats software, assuming five genetic models (co-dominant, dominant, recessive, over-dominant, and log-additive), with the G allele as the reference allele. The value of 0.05 was set as the threshold for statistical significance.

RESULTS

CD33 rs3865444 was associated with MS risk in the dominant (GG vs. GT + TT; OR (95% C.I.) = 0.79 (0.63-0.99), p = 0.041) and the over-dominant (GG + TT vs. GT; OR (95% C.I.) = 0.77 (0.61-0.97), p = 0.03) modes of inheritance. Given that the GG genotype was more frequent and the GT genotype was less frequent in MS patients compared to controls-while the observed frequency of the TT genotype did not differ between the two groups-the observed difference in MS risk may be stemming from either the GG (as a risk factor) or the GT (as a protective factor) genotype of CD33 rs3865444.

CONCLUSIONS

Our preliminary results suggest a possible contribution of CD33 rs3865444 to MS. Therefore, larger multiethnic studies should be conducted, investigating the role of CD33 rs3865444 in MS.

Heterogeneity of Baló's concentric sclerosis: a study of eight cases with different therapeutic concepts

Background

Baló’s Concentric Sclerosis (BCS) is a rare heterogeneous demyelinating disease with a variety of phenotypes on Magnetic Resonance Imaging (MRI). Existing literature lacks data especially on the therapeutic approach of the disease which we intended to elucidate by means of suggesting a new possible BCS classification and introducing different therapeutic concepts based on each BCS-subgroup characteristics.

Methods

We present a retrospective study of eight treated patients with BCS-type lesions, emphasizing on MRI characteristics and differences on therapeutic maneuvers.

Results

Data analysis showed: at disease onset the BCS-type lesion was tumefactive (size ≥2 cm) in 6 patients, with a mean size of 2.7 cm (± 0.80 SD); a coexistence of MS-like plaques on brain MRI was identified in 7 patients of our cohort. The mean age was 26.3 years (±7.3 SD) at disease onset and the mean follow-up period was 56.8 months (range 9–132 months). According to radiological characteristics and response to therapies, we further categorized them into 3 subgroups: a) Group-1; BCS with or without coexisting nonspecific white matter lesions; poor response to intravenous methylprednisolone (IVMP); treated with high doses of immunosuppressive agents (4 patients), b) Group-2; BCS with typical MS lesions; good response to IVMP; treated with MS-disease modifying therapies (2 patients), c) Group-3; BCS with typical MS lesions; poor response to IVMP; treated with rituximab (2 patients).

Conclusions

Our study introduces a new insight regarding the categorization of BCS into three subgroups depending on radiological features at onset and during the course of the disease, in combination with the response to different immunotherapies. Immunosuppressive agents such as cyclophosphamide are usually effective in BCS. However, therapeutic alternatives like anti-CD20 monoclonal antibodies or more classical disease-modifying MS therapies can be considered when BCS has also mixed lesions similar to MS. Future studies with a larger sample size are necessary to further establish these findings, thus leading to better treatment algorithms and improved clinical outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-020-01971-2.

Paroxysmal Lower Limb Tremor as a Rare Presentation of Colloid Cyst of the Third Ventricle: A Case Report and Literature Review

Objective:

Colloid cysts of the third ventricle are benign intracranial tumors. They are most commonly presented with signs of intracranial hypertension due to obstructive hydrocephalus, including headache, nausea/vomiting and vision disturbances, whereas extrapyramidal symptoms such as tremor are very rare. Sudden death, due to abruptly developed hydrocephalus, can be also observed. Although paroxysmal symptomatology attributed to the intermittent obstruction of the foramen of Monro is considered the “classical” clinical presentation, it is rather the exception in clinical practice.

Case Report:

A 42-year-old woman with no medical history was admitted to the neurology department as suffering from a potential demyelinating disease due to episodes of paroxysmal tremor of her right lower limb and persistent mild gait instability, which presented 15 days prior to her arrival. She also complained of episodes of partially position-dependent bilateral headache over the last 10 years, as well as episodes of vertigo over the last 4 years. On arrival, her gait was shuffling and mildly wide-based and an intermittent tremor of her right lower limb was observed in supine and sitting positions, but not in a prone position. Brain magnetic resonance imaging (MRI) demonstrated a round cystic lesion of the third ventricle, accompanied by hydrocephalus with enlargement of lateral ventricles. MRI findings were highly indicative of a colloid cyst. The patient underwent resection of the mass and the tremor resolved after surgery.

Conclusion:

Given the greatly heterogeneous clinical presentation of colloid cysts, our case highlights the significance of the prompt diagnosis of this rare but potentially fatal cause of paroxysmal limb tremor.

Recurrent Fulminant Tumefactive Demyelination With Marburg-Like Features and Atypical Presentation: Therapeutic Dilemmas and Review of Literature

Atypical forms of demyelinating diseases with tumor-like lesions and aggressive course represent a diagnostic and therapeutic challenge for neurologists. Herein, we describe a 50-year-old woman presenting with subacute onset of left hemiparesis, memory difficulties and headache. Brain MRI revealed a tumefactive right frontal-parietal lesion with perilesional edema, mass effect and homogenous post-contrast enhancement, along with other small atypical lesions in the white-matter. Brain biopsy of cerebral lesion ruled out lymphoma or any other neoplastic process and patient placed on corticosteroids with complete clinical/radiological remission. Two years after disease initiation, there was disease exacerbation with reappearance of the tumor-like mass. The patient initially responded to high doses of corticosteroids but soon became resistant. Plasma-exchange sessions were not able to limit disease burden. Resistance to therapeutic efforts led to a second biopsy that showed perivascular demyelination, predominantly consisting of macrophages, with a small number of T and B lymphocytes, and the presence of reactive astrocytes, typical of Creutzfeldt-Peters cells. The patient received high doses of cyclophosphamide with substantial clinical/radiological response but relapsed after 7-intensive cycles. She received 4-weekly doses of rituximab with disease exacerbation and brainstem involvement. She eventually died with complicated pneumonia. We present a very rare case of recurrent tumefactive demyelinating lesions, with atypical tumor-like characteristics, with initial response to corticosteroids and cyclophosphamide, but subsequent development of drug-resistance and unexpected exacerbation upon rituximab administration. Our clinical case raises therapeutic dilemmas and points to the need for immediate and appropriate immunosuppression in difficult to treat tumefactive CNS lesions with Marburg-like features.

Wide range of reduced penetrance alleles in spinal and bulbar muscular atrophy: a model-based approach

BACKGROUND

Spinal and bulbar muscular atrophy (SBMA), also known as Kennedy's disease, is an X-linked motor neuron disorder caused by an expanded CAG repeat in the gene coding for the androgen receptor (AR). The range and significance of reduced penetrance alleles in SBMA has not been fully determined to date. We presently sought to determine the range of reduced penetrance alleles in SBMA.

METHODS

Through systematic literature review and meta-analysis, we collected and analysed data from 2576 patients with SBMA and compared the distributions of the CAG repeat number (CAG)_n in the AR gene between patients and 112 248 control alleles of the general population.

RESULTS

Our analysis revealed an unexpectedly high frequency of expanded SBMA-associated alleles, with (CAG)_n ≥35 present in 107/100,000 and (CAG)_n ≥38 present in 27/100,000 of the general population. Consequently, we suggest an updated model describing the distribution of expanded alleles in the general population. We argue against the established cut-off principle for the penetrance of SBMA and suggest that penetrance gradually increases from 35 to approximately 46 (CAG)_n, above which it reaches a plateau approaching maximum value.

CONCLUSION

Asymptomatic men of the general population with no/unknown SBMA family history are free of risk when carrying (CAG)_n ≤34, are at intermediate but increasing risk for developing SBMA when carrying (CAG)_n ≈35-46 and have close to 100% risk of developing the disease when carrying (CAG)_n ≥47. The above observations should be helpful and clinically useful when providing genetic counselling to individuals and families bearing SBMA-associated alleles.

Evidence for Cognitive Deficits in X-Linked Charcot-Marie-Tooth Disease

OBJECTIVE

X-linked Charcot-Marie-Tooth disease (CMTX) is an hereditary neuropathy caused by mutations in GJB1 coding for connexin-32, found in Schwann cells, but also expressed in oligodendrocytes. Reports have identified CNS involvement in CMTX, but no systematic study of cognitive function has been published.

METHODS

We assessed 24 CMTX patients (13 males; 9GJB1 mutations) with a comprehensive neuropsychological battery, including tests of memory, language, and executive functions.

RESULTS

No differences in cognitive performance were observed between males and females. A case-by-case investigation revealed selective deficits in individual patients. One subgroup (29%) demonstrated executive abnormalities; and a non-overlapping subgroup (29%), prominent reading (decoding) abnormalities.

CONCLUSIONS

The present data provide evidence for cognitive deficits in CMTX. Emerging neuropsychological patterns are also discussed.

Deciphering anti-MOG IgG antibodies: Clinical and radiological spectrum, and comparison of antibody detection assays

IgG antibodies to myelin oligodendrocyte glycoprotein (MOG) detected by cell based assays (CBA) have been identified in a constantly expanding spectrum of CNS demyelinating disorders. However, a universally accepted CBA has not been adopted yet. We aimed to analyze the clinical and radiological features of patients with anti-MOG IgG1-antibodies detected with a live-cell CBA and to compare the three most popular MOG-CBAs. We screened sera from 1300 Greek patients (including 426 patients referred by our 8 clinics) suspected for anti-MOG syndrome, and 120 controls with the live-cell MOG-CBA for IgG1-antibodies. 41 patients, versus 0 controls were seropositive. Clinical, serological and radiological data were available and analyzed for the 21 seropositive patients out of the 426 patients of our clinics. Their phenotypes were: 8 optic neuritis, 3 myelitis, 3 neuromyelitis optica, 2 encephalomyelitis, 2 autoimmune encephalitis and 3 atypical MS. We then retested all sera of our 426 patients with the other two most popular MOG-CBAs for total IgG (a live-cell and a commercial fixed-cell CBAs). Seven IgG1-seropositive patients were seronegative for one or both IgG-CBAs. Yet, all 21 patients had clinical and radiological findings previously described in MOG-antibody associated demyelination disease supporting the high specificity of the IgG1-CBA. In addition, all IgG1-CBA-negative sera were also negative by the IgG-CBAs. Also, all controls were negative by all three assays, except one serum found positive by the live IgG-CBA. Overall, our findings support the wide spectrum of anti-MOG associated demyelinating disorders and the superiority of the MOG-IgG1 CBA over other MOG-CBAs.

Recurrent myelitis and asymptomatic hypophysitis in IgG4-related disease: case-based review

IgG4-related disease (IgG4-RD) is a disorder with various clinical manifestations. Central nervous system (CNS) involvement is well recognized, with hypertrophic pachymeningitis and hypophysitis being the most common manifestations. Spinal cord involvement is an extremely rare manifestation. We present the first case of an IgG4-RD patient with spinal cord parenchymal disease and concurrent hypophysitis. We review also the current literature about CNS parenchymal involvement in the context of IgG4-RD. A young female presented with clinical symptoms of myelitis. Cervical spinal cord magnetic resonance imaging (MRI) displayed features of longitudinally extensive transverse myelitis (LETM). Brain MRI showed a small number of high-intensity lesions in the deep white matter and enlargement of hypophysis with homogeneous gadolinium enhancement (asymptomatic hypophysitis). Diagnostic workup revealed elevated IgG4 serum levels (146 mg/dL). Our patient fulfilled the organ-specific diagnostic criteria of IgG4-hypophysitis. Treatment with intravenous glucocorticoids led to rapid clinical response, and to the substantial resolution of imaging findings. Azathioprine was used as a maintenance treatment. One relapse occurred 2 years after the initial diagnosis and patient was re-treated with glucocorticoids. Three years after relapse, patient is in remission with azathioprine. We present the first case of myelitis with radiological features of LETM associated with increased IgG4 serum levels and the simultaneous presence of asymptomatic IgG4-related hypophysitis.

P4136Neurogenic stunned myoacardium in multiple sclerosis patients

Method

We enrolled 50 asymptomatic fulfilling the criteria MS patients, aged 45±7 years old and disease in our study duration of 6±13 years with EDSS= 2,5. After echocardiography and clinical examination as primary screening, pharmacologic stress thallium 201 scintigraphy and/or coronary angiography were performed to identify the incidence of NSM. Clinical characteristics of MS, type of disease, treatments as well as localization of demyelinating plaques (DP) were noted.

Results

13 patients (26%) had abnormal scintigraphy test although clinical profile was not indicative. Cardiac ultrasound showed that 2 patients from this group had a critical ejection fraction (around 50%). All positive patients that underwent for coronary angiogram were negative implying coronary artery spasm as a potential mechanism for the stress positive result. A common finding of all positive patients was the localization of DP which was in the lateral horn of the lower cervical part (C5–7) and upper thoracic part (Th1–4). No correlation seems to have the presence of CAD with disease duration, EDSS and treatment approaches.

Discussion

Our study shows a high incidence of NSM. This finding due to the location of the DP seems to correlate with ANS disturbance and might help to distinguish patients at higher risk.

TREM2 R47H (rs75932628) variant is unlikely to contribute to Multiple Sclerosis susceptibility and severity in a large Greek MS cohort

BACKGROUND

Multiple Sclerosis is a multifactorial autoimmune disease of the central nervous system, characterized by focal inflammation, demyelination and secondary axonal injury. TREM2 is a signaling protein which participates in the innate immune system by implication to inflammation, proliferation and phagocytosis. The R47H (rs75392628) rare variant of the TREM2 gene has been related to various neurological diseases and leads to impaired signaling, lipoprotein binding, lipoprotein uptake and surface uptake.

AIM

To assess the role of TREM2 rs75932628 on MS risk through a genetic candidate gene association case-control study in a Greek population.

METHODS

1246 MS cases and 398 controls were genotyped for this variant.

RESULTS

No MS or healthy subjects carried the variant.

CONCLUSION

This variant does not seem to play a determining role in the pathogenesis of MS, although further studies examining the presence of TREM2 mutations in other, phylogenetically different populations and the epigenetic regulation of this gene are needed in order to thoroughly investigate its role in MS.

Mutational screening of the SH3TC2 gene in Greek patients with suspected demyelinating recessive Charcot-Marie-Tooth disease reveals a varied and unusual phenotypic spectrum

Charcot-Marie-Tooth disease type 4 C (CMT4C) is an autosomal recessive form of demyelinating peripheral neuropathy caused by mutations in SH3TC2, characterized by early onset, spine deformities, and cranial nerve involvement. We screened SH3TC2 in 50 unrelated Greek patients with suspected demyelinating Charcot-Marie-Tooth disease and pedigree compatible with recessive inheritance. All patients had been previously screened for PMP22, GJB1, and MPZ mutations. We found five previously identified pathogenic mutations in SH3TC2 distributed among 13 patients in homozygosity or compound heterozygosity (p. Arg954Stop, Arg1109Stop, Gln892Stop, Ala878Asp, and Arg648Trp). Although most cases had early onset and spine deformities were almost omnipresent, a wide phenotypic spectrum was observed. Particularly notable were two siblings with Roussy-Lévy syndrome and one patient with young-onset trigeminal neuralgia. In conclusion, mutations in SH3TC2 are responsible for 26% of Greek patients with suspected CMT4, identifying CMT4C as the most common recessive demyelinating neuropathy in the Greek population, in accordance with other Mediterranean cohorts.

X linked Charcot-Marie-Tooth disease and multiple sclerosis: emerging evidence for an association

OBJECTIVE

X linked Charcot-Marie-Tooth disease (CMTX) is a hereditary neuropathy caused by mutations in GJB1 coding for connexin-32, a gap junction protein expressed in Schwann cells, but also found in oligodendrocytes. Four patients with CMTX developing central nervous system (CNS) demyelination compatible with multiple sclerosis (MS) have been individually published. We presently sought to systematically investigate the relationship between CMTX and MS.

METHODS

Over 20 years, 70 consecutive patients (36 men) with GJB1 mutations were identified at our Neurogenetics Unit, Athens, Greece, and assessed for clinical features suggestive of MS. Additionally, 18 patients with CMTX without CNS symptoms and 18 matched controls underwent brain MRI to investigate incidental findings. Serum from patients with CMTX and MS was tested for CNS immunoreactivity.

RESULTS

We identified three patients with CMTX who developed clinical features suggestive of inflammatory CNS demyelination fulfilling MS diagnostic criteria. The resulting 20-year MS incidence (4.3%) differed significantly from the highest background 20-year MS incidence ever reported from Greece (p=0.00039). The search for incidental brain MRI findings identified two CMTX cases (11%) with lesions suggestive of focal demyelination compared with 0 control. Moreover, 10 cases in the CMTX cohort had hyperintensity in the splenium of the corpus callosum compared with 0 control (p=0.0002). No specific CNS-reactive humoral factors were identified in patients with CMTX and MS.

CONCLUSIONS

We have demonstrated a higher than expected frequency of MS in patients with CMTX and identified incidental focal demyelinating lesions on brain MRI in patients with CMTX without CNS symptoms. This provides circumstantial evidence for GJB1 mutations acting as a possible MS risk factor.

Ocular flutter as presenting manifestation of pediatric MOG antibody–associated demyelination: A case report

A 13-year-old girl presented with a 5-day history of oscillopsia. On examination, ocular flutter and mild cerebellar signs were found. Brain magnetic resonance imaging (MRI) revealed four periventricular and subcortical non-enhancing lesions. Cerebrospinal fluid (CSF) oligoclonal bands were negative. Neuroblastoma or other malignancies were not found. She responded well to a corticosteroid–intravenous immunoglobulin (IVIG) combination and remained symptom-free for 3 years until presenting again with isolated ocular flutter. Brain MRI at this time remained atypical for classic multiple sclerosis (MS) with a predominance of juxtacortical demyelinating lesions. CSF was positive for oligoclonal bands. Serum myelin oligodendrocyte glycoprotein (MOG) antibodies were present. Ocular flutter can be the presenting feature of MOG antibody–associated pediatric demyelination.

A case of Alemtuzumab-induced neutropenia in multiple sclerosis in association with the expansion of large granular lymphocytes

BACKGROUND

Alemtuzumab has been demonstrated to reduce the risks of relapse and accumulation of sustained disability in Multiple Sclerosis (MS) patients compared to β-interferon. It acts against CD52, leading primarily to lymphopenia. Recent data have shown that mild neutropenia is observed in 16% of treated MS-patients whereas severe neutropenia occurred in 0.6%.

CASE PRESENTATION

Herein, we present the case of a 34-year-old woman with relapsing-remitting MS, with a history of treatment with glatiramer acetate and natalizumab, who subsequently received Alemtuzumab (12 mg / 24 h × 5 days). 70-days after the last Alemtuzumab administration, the patient displayed neutropenia (500 neutrophils/μL) with virtual absence of B-cells (0.6% of total lymphocytes), low values of CD4-T-cells (6.6%) and predominance of CD8-T-cells (48%) and NK-cells (47%); while large granular lymphocytes (LGL) predominated in the blood-smear examination. Due to prolonged neutropenia (5-days) the patient was placed on low-dose corticosteroids leading to sustained remission.

CONCLUSION

This is the first case of a patient with relapsing-remitting MS with neutropenia two months post-Alemtuzumab, with simultaneous presence of LGL cells in the blood and a robust therapeutic response to prednisolone. We recommend testing with a complete blood count every 15 days in the first 3 months after the 1st Alemtuzumab administration and searching for large granular lymphocytes cell expansion on microscopic examination of the peripheral blood if neutropenia develops.

Replication study of GWAS risk loci in Greek multiple sclerosis patients

OBJECTIVES

To validate in an ethnically homogeneous Greek multiple sclerosis (MS) cohort, genetic risk factors for the disease, identified through a number of previous multi-ethnic genome-wide association studies (GWAS).

METHODS

A total of 1228 MS cases and 1014 controls were recruited in the study, from 3 MS centers in Greece. We genotyped 35 susceptibility SNPs that emerged from previous GWAS or meta-analyses of GWAS. Allele and genotype single locus regression analysis, adjusted for gender and site, was performed. Permutation testing was applied to all analyses.

RESULTS

Six polymorphisms reached statistical significance (permutation p value < 0.05). In particular, rs2760524 of LOC105371664, near RGS1 (permutation p value 0.001), rs3129889 of HLA-DRA, near HLA-DRB1 (permutation p value < 1.00e-04), rs1738074 of TAGAP (permutation p value 0.007), rs703842 of METTL1/CYP27B1 (permutation p value 0.008), rs9596270 of DLEU1 (permutation p value < 1.00e-04), and rs17445836 of LincRNA, near IRF8 (permutation p value 0.001) were identified as susceptibility risk factors in our group.

CONCLUSION

The current study replicated a number of GWAS susceptibility SNPs, which implies that some similarities between the examined Greek population and the MS genetic architecture of the GWAS populations do exist.

The different faces of the p. A53T alpha-synuclein mutation: A screening of Greek patients with parkinsonism and/or dementia

BACKGROUND

The p. A53T mutation in the alpha-synuclein (SNCA) gene is a rare cause of autosomal dominant Parkinson's disease (PD). Although generally rare, it is particularly common in the Greek population due to a founder effect. A53T-positive PD patients often develop dementia during disease course and may very rarely present with dementia.

METHODS

We screened for the p. A53T SNCA mutation a total of 347 cases of Greek origin with parkinsonism and/or dementia, collected over 15 years at the Neurogenetics Unit, Eginition Hospital, University of Athens. Cases were classified into: "pure parkinsonism", "pure dementia" and "parkinsonism plus dementia".

RESULTS

In total, 4 p. A53T SNCA mutation carriers were identified. All had autosomal dominant family history and early onset. Screening of the "pure parkinsonism" category revealed 2 cases with typical PD. The other two mutation carriers were identified in the "parkinsonism plus dementia" category. One had a diagnosis of PD dementia and the other of behavioral variant frontotemporal dementia. Screening of patients with "pure dementia" failed to identify any further A53T-positive cases.

CONCLUSIONS

Our results confirm that the p. A53T SNCA mutation is relatively common in Greek patients with PD or PD plus dementia, particularly in cases with early onset and/or autosomal dominant family history.

Spastic paretic hemifacial contracture as a presenting feature of multiple sclerosis

BACKGROUND

Spastic paretic hemifacial contracture (SPHC) is characterized by sustained unilateral contraction of the facial muscles associated with mild ipsilateral facial paresis. Rarely described in the context of multiple sclerosis (MS), it has never been reported as presenting symptom of MS.

CASE REPORTS

Two patients developed SPHC within the context of a clinically isolated syndrome suggestive of MS. EMG revealed continuous resting activity of irregularly firing motor unit potentials, associated with impaired recruitment upon voluntary contraction. SPHC remitted fully in both patients.

CONCLUSIONS

SPHC, a rare but distinct clinical and EMG entity, can occasionally be the presenting feature of MS.

Frontotemporal dementia as the presenting phenotype of p.A53T mutation carriers in the alpha-synuclein gene

INTRODUCTION

The p.A53T point mutation in SNCA, the alpha-synuclein gene, has been linked to a rare dominant form of Parkinson's disease (PD).

METHODS

Here, we describe two apparently unrelated cases of p.A53T (G209A) SNCA mutation carriers with an atypical initial manifestation and disease course. Moreover, cerebrospinal fluid (CSF) levels of tau, p-tau and amyloid Aβ42 were measured in these patients and in an additional cohort of 5 symptomatic and 2 asymptomatic p.A53T carriers without an initial manifestation of dementia.

RESULTS

Both patients exhibited an early onset frontal-dysexecutive dysfunction with apathy and emotional blunting resembling frontotemporal dementia (FTD). Motor symptoms typical of Parkinson's disease appeared only later in the disease course and were less prominent than cognitive ones, which included language impairment. Autonomic dysfunction and myoclonus also emerged in a more advanced disease stage. In both patients, Brain Magnetic Resonance Imaging showed fronto-temporo-parietal atrophy, and CSF analysis showed elevated tau protein levels. In contrast, tau protein levels were normal in a cohort of 7 other p.A53T mutation carriers (5 symptomatic/2 asymptomatic). A screen of Greek patients presenting with frontotemporal dementia failed to identify any additional subjects with the p.A53T SNCA mutation.

CONCLUSION

Although cognitive decline has been recognized as a feature of the full-blown clinical picture of p.A53T related parkinsonism, a predominant frontotemporal dementia-like phenotype at presentation has not been previously described. This may represent a subtype of this disorder, with distinctive clinical, imaging and CSF biochemical characteristics, in which additional genetic or epigenetic factors may play a role.