Luca Magistrelli

Peripheral nervous system involvement in Parkinson's disease: Evidence and controversies

BACKGROUND In recent years, non-motor features of Parkinsons disease (PD) have received increasing attention and PD is currently considered a systemic rather than a pure basal ganglia disorder. Among the systemic features, peripheral neuropathy (PN) is a recent acquisition since the first case-control study reporting increased frequency of PN in PD dates back to 2008. METHODS We reviewed available literature on peripheral nervous system (PNS) involvement in PD. RESULTS Evidence of α-synuclein deposition in the PNS and small nerve fiber deterioration in both drug-naïve and treated PD patients is becoming stronger. In addition, several recent reports documented a significant role of levodopa exposure together with group B vitamin deficiency in facilitating the development of PN and case reports suggested that treatment with continuous levodopa intestinal infusion may increase the risk of acute PN compared to both oral levodopa and other dopaminergic treatments. CONCLUSION It is currently debated whether PN is an intrinsic disease-related feature, a consequence of levodopa treatment or both. In this review, we will discuss the different hypotheses, as well as our perspective on open issues and controversies.

Polymorphisms of Dopamine Receptor Genes and Risk of L-Dopa–Induced Dyskinesia in Parkinson’s Disease

L-dopa–induced dyskinesia (LID) is a frequent motor complication of Parkinson’s disease (PD), associated with a negative prognosis. Previous studies showed an association between dopamine receptor (DR) gene (DR) variants and LID, the results of which have not been confirmed. The present study is aimed to determine whether genetic differences of DR are associated with LID in a small but well-characterized cohort of PD patients. To this end we enrolled 100 PD subjects, 50 with and 50 without LID, matched for age, gender, disease duration and dopaminergic medication in a case-control study. We conducted polymerase chain reaction for single nucleotide polymorphisms (SNP) in both D1-like (DRD1A48G; DRD1C62T and DRD5T798C) and D2-like DR (DRD2G2137A, DRD2C957T, DRD3G25A, DRD3G712C, DRD4C616G and DRD4nR VNTR 48bp) analyzed genomic DNA. Our results showed that PD patients carrying allele A at DRD3G3127A had an increased risk of LID (OR 4.9; 95% CI 1.7–13.9; p = 0.004). The present findings may provide valuable information for personalizing pharmacological therapy in PD patients.

Correction to: Villaret syndrome as clinical presentation of occult metastatic breast cancer

The author’s given name and family name were initially interchanged inadvertently. The correct names have been corrected above. The original article was corrected.

Correction to: The Italian Dystonia Registry: rationale, design and preliminary findings

In the original article, Gina Ferrazzano was affiliated to Department of Neurology and Psychiatry, Neuromed Institute IRCCS, Sapienza University of Rome, Pozzilli, Italy.The corrected affiliation should be: Neuromed Institute IRCCS, Pozzilli, IS, Italy.

Villaret syndrome as clinical presentation of occult metastatic breast cancer

Dear Editor, Villaret syndrome is a rare neurological picture with unilateral involvement of four cranial nerves, from the ninth to the twelfth, associated with the Horner’s sign [1]. It may be caused by skull base masses at the retroparotideal space, including both primary tumors [2] and metastatic localization of lung [2], breast [3], or prostatic neoplasms [4]. Moreover, it can be related to an internal carotid dissection [5] or some infections [6]. Here we describe a case of Villaret syndrome due to an occult metastatic breast tumor.

Parkinson’s disease patients have a complex phenotypic and functional Th1 bias: cross-sectional studies of CD4+ Th1/Th2/T17 and Treg in drug-naïve and drug-treated patients

BackgroundParkinson’s disease (PD) affects an estimated 7 to 10 million people worldwide, and only symptomatic treatments are presently available to relieve the consequences of brain dopaminergic neurons loss. Neuronal degeneration in PD is the consequence of neuroinflammation in turn influenced by peripheral adaptive immunity, with CD4+ T lymphocytes playing a key role. CD4+ T cells may however acquire proinflammatory phenotypes, such as T helper (Th) 1 and Th17, as well as anti-inflammatory phenotypes, such as Th2 and the T regulatory (Treg) one, and to what extent the different CD4+ T cell subsets are imbalanced and their functions dysregulated in PD remains largely an unresolved issue.MethodsWe performed two cross-sectional studies in antiparkinson drug-treated and drug-naïve PD patients, and in age- and sex-matched healthy subjects. In the first one, we examined circulating Th1, Th2, Th17, and in the second one circulating Treg. Number and frequency of CD4+ T cell subsets in peripheral blood were assessed by flow cytometry and their functions were studied in ex vivo assays. In both studies, complete clinical assessment, blood count and lineage-specific transcription factors mRNA levels in CD4+ T cells were independently assessed and thereafter compared for their consistency.ResultsPD patients have reduced circulating CD4+ T lymphocytes, due to reduced Th2, Th17, and Treg. Naïve CD4+ T cells from peripheral blood of PD patients preferentially differentiate towards the Th1 lineage. Production of interferon-γ and tumor necrosis factor-α by CD4+ T cells from PD patients is increased and maintained in the presence of homologous Treg. This Th1-biased immune signature occurs in both drug-naïve patients and in patients on dopaminergic drugs, suggesting that current antiparkinson drugs do not affect peripheral adaptive immunity.ConclusionsThe complex phenotypic and functional profile of CD4+ T cell subsets in PD patients strengthen the evidence that peripheral adaptive immunity is involved in PD, and represents a target for the preclinical and clinical assessment of novel immunomodulating therapeutics.

The Length of SNCA Rep1 Microsatellite May Influence Cognitive Evolution in Parkinson’s Disease

Background Alpha-synuclein is a constituent of Lewy bodies and mutations of its gene cause familial Parkinson’s disease (PD). A previous study showed that a variant of the alpha-synuclein gene (SNCA), namely the 263 bp allele of Rep1 was associated with faster motor progression in PD. On the contrary, a recent report failed to detect a detrimental effect of Rep1 263 on both motor and cognitive outcomes in PD. Aim of this study was to evaluate the influence of the Rep1 variants on disease progression in PD patients. Methods We recruited and genotyped for SNCA Rep1 426 PD patients with age at onset ≥40 years and disease duration ≥4 years. We then analyzed frequency and time of occurrence of wearing-off, dyskinesia, freezing of gait, visual hallucinations, and dementia using a multivariate Cox’s proportional hazards regression model. Results SNCA Rep1 263 carriers showed significantly increased risk of both dementia (HR = 3.03) and visual hallucinations (HR = 2.69) compared to 263 non-carriers. Risk of motor complications did not differ in the two groups. Conclusion SNCA Rep1 263 allele is associated with a worse cognitive outcome in PD.

Primary brain calcification: an international study reporting novel variants and associated phenotypes

Primary familial brain calcification (PFBC) is a rare cerebral microvascular calcifying disorder with a wide spectrum of motor, cognitive, and neuropsychiatric symptoms. It is typically inherited as an autosomal-dominant trait with four causative genes identified so far: SLC20A2, PDGFRB, PDGFB, and XPR1. Our study aimed at screening the coding regions of these genes in a series of 177 unrelated probands that fulfilled the diagnostic criteria for primary brain calcification regardless of their family history. Sequence variants were classified as pathogenic, likely pathogenic, or of uncertain significance (VUS), based on the ACMG-AMP recommendations. We identified 45 probands (25.4%) carrying either pathogenic or likely pathogenic variants (n = 34, 19.2%) or VUS (n = 11, 6.2%). SLC20A2 provided the highest contribution (16.9%), followed by XPR1 and PDGFB (3.4% each), and PDGFRB (1.7%). A total of 81.5% of carriers were symptomatic and the most recurrent symptoms were parkinsonism, cognitive impairment, and psychiatric disturbances (52.3%, 40.9%, and 38.6% of symptomatic individuals, respectively), with a wide range of age at onset (from childhood to 81 years). While the pathogenic and likely pathogenic variants identified in this study can be used for genetic counseling, the VUS will require additional evidence, such as recurrence in unrelated patients, in order to be classified as pathogenic.

Auditory seizures in autoimmune epilepsy: a case with anti‐thyroid antibodies

In its classic presentation, Hashimotos encephalopathy is an acute-subacute complex neuropsychiatric syndrome with cognitive impairment, hallucinations, myoclonus, tremor or ataxia, associated with elevated anti-thyroid antibodies. Corticoids and immunotherapy are dramatically effective. However, in some cases, not all the associated features are presented and this delays diagnosis and appropriate treatment. We describe a man with abrupt onset of recurrent auditory seizures resulting in refractory non-convulsive status epilepticus. The patient was diagnosed with an autoimmune encephalopathy with elevated serum and CSF anti-thyroid antibodies. None of the antiepileptic drugs were successful, however, following immune-modulating therapy, the refractory non-convulsive status epilepticus dramatically improved, as did the patient overall. We suggest that Hashimotos encephalopathy should be suspected in otherwise healthy patients with unexplained new-onset focal recurrent auditory seizures which do not respond to antiepileptic drugs. The presence of anti-thyroid antibodies in the CSF supports this diagnosis.

Abnormal postural reflexes in a patient with pontine ischaemia.

The control of body posture is a complex activity that needs a very close relationship between different structures, such as the vestibular system, and the muscle and joint receptors of the neck. Damage of even one of these structures can lead to abnormal postural reflexes. We describe a case of a woman with a left pontine ischaemia who developed a ‘dystonic’ extensor posture of the left limbs while turned on the right side. This clinical picture differs from previous reports on the subject, and may relate to ischaemic damage of a pontine structure involved in posture control, or of adjacent neural connections to be yet identified. To the best of our knowledge, this is the first case reported in the literature. Clinical examples of an altered interplay between vestibular and neck receptors are rare.