Enrico Granieri

The diagnostic criteria for small fibre neuropathy: from symptoms to neuropathology

Small fibre neuropathy (SFN), a condition dominated by neuropathic pain, is frequently encountered in clinical practise either as prevalent manifestation of more diffuse neuropathy or distinct nosologic entity. Aetiology of SFN includes pre-diabetes status and immune-mediated diseases, though it remains frequently unknown. Due to their physiologic characteristics, small nerve fibres cannot be investigated by routine electrophysiological tests, making the diagnosis particularly difficult. Quantitative sensory testing (QST) to assess the psychophysical thresholds for cold and warm sensations and skin biopsy with quantification of somatic intraepidermal nerve fibres (IENF) have been used to determine the damage to small nerve fibres. Nevertheless, the diagnostic criteria for SFN have not been defined yet and a ‘gold standard’ for clinical practise and research is not available. We screened 486 patients referred to our institutions and collected 124 patients with sensory neuropathy. Among them, we identified 67 patients with pure SFN using a new diagnostic ‘gold standard’, based on the presence of at least two abnormal results at clinical, QST and skin biopsy examination. The diagnosis of SFN was achieved by abnormal clinical and skin biopsy findings in 43.3% of patients, abnormal skin biopsy and QST findings in 37.3% of patients, abnormal clinical and QST findings in 11.9% of patients, whereas 7.5% patients had abnormal results at all the examinations. Skin biopsy showed a diagnostic efficiency of 88.4%, clinical examination of 54.6% and QST of 46.9%. Receiver operating characteristic curve analysis confirmed the significantly higher performance of skin biopsy comparing with QST. However, we found a significant inverse correlation between IENF density and both cold and warm thresholds at the leg. Clinical examination revealed pinprick and thermal hypoesthesia in about 50% patients, and signs of peripheral vascular autonomic dysfunction in about 70% of patients. Spontaneous pain dominated the clinical picture in most SFN patients. Neuropathic pain intensity was more severe in patients with SFN than in patients with large or mixed fibre neuropathy, but there was no significant correlation with IENF density. The aetiology of SFN was initially unknown in 41.8% of patients and at 2-year follow-up a potential cause could be determined in 25% of them. Over the same period, 13% of SFN patients showed the involvement of large nerve fibres, whereas in 45.6% of them the clinical picture did not change. Spontaneous remission of neuropathic pain occurred in 10.9% of SFN patients, while it worsened in 30.4% of them.

Restless legs syndrome and pregnancy

Objective: To perform a large and detailed epidemiologic study on restless legs syndrome (RLS) during pregnancy and the puerperium. Methods: A structured clinical interview, assessing symptoms since the beginning of pregnancy, was performed to a population of 642 pregnant women at the time of delivery and at follow-up evaluation (1, 3, and 6 months after delivery). Main hematologic tests were also evaluated. A woman was considered affected if she met the International RLS Study Group criteria for RLS diagnosis. Results: Twenty-six percent of women were affected by RLS during their pregnancy. The disease was strongly related to the third trimester of pregnancy and tended to disappear reaching the time of delivery. Affected women presented lower values of hemoglobin and mean corpuscular volume compared with healthy subjects (both groups received the same supplemental iron and folate therapy). Conclusions: Pregnancy is associated with transient restless legs syndrome.

Case-control study of risk factors of Creutzfeldt-Jakob disease in Europe during 1993-95

BACKGROUND Creutzfeldt-Jakob disease (CJD) is a transmissible spongiform encephalopathy. Genetic and iatrogenic forms have been recognised but most are sporadic and of unknown cause. We have studied risk factors for CJD as part of the 1993-95 European Union collaborative studies of CJD in Europe. METHODS The 405 patients with definite or probable CJD who took part in our study had taken part in population-based studies done between 1993 and 1995 in Belgium, France, Germany, Italy, the Netherlands, and the UK. Data on putative risk factors from these patients were compared with data from 405 controls. FINDINGS We found evidence for familial aggregation of CJD with dementia due to causes other than CJD (relative risk [RR] 2.26, 95% CI 1.31-3.90). No significant increased risk of CJD in relation to a history of surgery and blood transfusion was shown. There was no evidence for an association between the risk of CJD and the consumption of beef, veal, lamb, cheese, or milk. No association was found with occupational exposure to animals or leather. The few positive findings of the study include increased risk in relation to consumption of raw meat (RR 1.63 [95% CI 1.18-2.23]) and brain (1.68 [1.18-2.39]), frequent exposure to leather products (1.94 [1.13-3.33]), and exposure to fertiliser consisting of hoofs and horns (2.32 [1.38-2.91]). Additional analyses, for example stratification by country and of exposures pre-1985 and post-1985, suggest that these results should be interpreted with great caution. INTERPRETATION Within the limits of the retrospective design of the study, our findings suggest that genetic factors other than the known CJD mutations may play an important part in CJD. Iatrogenic transmission of disease seems rare in this large population-based sample of patients with CJD. There is little evidence for an association between the risk of CJD and either animal exposure, or consumption of processed bovine meat or milk products for the period studied.

A Descriptive Study of Epilepsy in the District of Copparo, Italy, 1964–1978

Summary: Worldwide investigation of the epidemiology of epilepsy has suggested wide variations in the frequency of convulsive disorders. However, descriptive studies in general populations cannot be completely comparable because of a remarkable methodological dishomogeneity in definition of epilepsy, classification of seizures, and ascertainment, collection, and selection of the cases. The position with regard to the Mediterranean people was still little known, and the few studies presently available from Italy offer underestimates of epilepsy frequency owing to incompleteness in case‐collection practices and lack of information about the incidence of the disease. Therefore, to verify the true frequency of epilepsy in our country, we performed a community‐based epidemiologic study of convulsive disorders in the district of Copparo (population 45,153) in northern Italy. Based on 278 accepted cases with “active” epilepsy, the prevalence per 1,000 population on December 31, 1978, was 6.2 (6.4 if standardized to the Italian population). The average annual incidence for the period 1964 through 1978 was 33.1 per 100,000 (38.3 if standardized). These results, similar to those found in other Western countries, support the view that the frequency of epilepsy in Italy as a whole is higher than that indicated by the Italian studies previously published, and suggest that epilepsy is evenly distributed in Europe and the United States. Antecedents which could be considered potential causes of epilepsy were found in 39.6%, and in 39.1% of the prevalence and incidence cases, respectively; for both prevalence and incidence groups, perinatal brain injuries were the most frequent event. This high proportion of epileptic cases with underlying causes emphasizes the urgency of planning precautionary measures in Italy to improve prenatal and perinatal medical care.

Encoding of human action in Broca's area.

Brocas area has been considered, for over a century, as the brain centre responsible for speech production. Modern neuroimaging and neuropsychological evidence have suggested a wider functional role is played by this area. In addition to the evidence that it is involved in syntactical analysis, mathematical calculation and music processing, it has recently been shown that Brocas area may play some role in language comprehension and, more generally, in understanding actions of other individuals. As shown by functional magnetic resonance imaging, Brocas area is one of the cortical areas activated by hand/mouth action observation and it has been proposed that it may form a crucial node of a human mirror-neuron system. If, on the one hand, neuroimaging studies use a correlational approach which cannot offer a final proof for such claims, available neuropsychological data fail to offer a conclusive demonstration for two main reasons: (i) they use tasks taxing both language and action systems; and (ii) they rarely consider the possibility that Brocas aphasics may also be affected by some form of apraxia. We administered a novel action comprehension test--with almost no linguistic requirements--on selected frontal aphasic patients lacking apraxic symptoms. Patients, as well as matched controls, were shown short movies of human actions or of physical events. Their task consisted of ordering, in a temporal sequence, four pictures taken from each movie and randomly presented on the computer screen. Patients performance showed a specific dissociation in their ability to re-order pictures of human actions (impaired) with respect to physical events (spared). Our study provides a demonstration that frontal aphasics, not affected by apraxia, are specifically impaired in their capability to correctly encode observed human actions.

Altered miRNA expression in T regulatory cells in course of multiple sclerosis.

OBJECTIVES Multiple sclerosis (MS) is a chronic inflammatory response against constituents of the central nervous system. It is known that regulatory T cells (Tregs) play a key role in the autoimmune balance and their improper function may facilitate the expansion of autoaggressive T cell clones. Recently, microRNAs (miRNAs) have been involved in autoimmune disorders and their loss-of-function in immune cells was shown to facilitate systemic autoimmune disorders. Here, we analyzed the miRNA expression profile in Tregs from MS-RR. METHODS We assessed miRNA genome-wide expression profile by microarray analysis on CD4(+)CD25(+high) T cells from 12 MS relapsing-remitting patients in stable condition and 14 healthy controls. Since CD4(+)CD25(+high) T cells comprise both T regulatory cells (CD4(+)CD25(+high)CD127(dim/-)) and T effector cells (CD4(+)CD25(+high)CD127(+)), we performed a quantitative RT-PCR on CD4(+)CD25(+high)CD127(dim/-) and CD4(+)CD25(+high)CD127(+) cells isolated from the same blood sample. RESULTS We found 23 human miRNAs differentially expressed between CD4(+)CD25(high)bona fide Treg cells from MS patients vs. healthy donors, but, conversely, among the deregulated miRNAs, members of the miR-106b-25 were found down-regulated in MS patients when compared to healthy donors in CD4(+)CD25(high)CD127(dim/-) T regulatory cells. More interesting, the ratio between Treg/Teff showed an enrichment of these microRNA in T regulatory cells derived from patients if compared to healthy controls. CONCLUSION miR-106b and miR-25 were previously shown to modulate the TGF-β signaling pathway through their action on CDKN1A/p21 and BCL2L11/Bim. TGF-β is involved in T regulatory cells differentiation and maturation. Therefore, the deregulation of this miRNA cluster may alter Treg cells activity in course of MS, by altering TGF-β biological functions.

Motor neuron disease in the province of Ferrara, Italy, in 1964–1982

We carried out an intensive incidence, prevalence, and mortality survey of motor neuron disease (MND) in the province of Ferrara, northern Italy. Based on 72 patients, the mean incidence per year for the period 1964 through 1982 was 0.98 cases per 100,000. On December 31, 1981, the prevalence rate was 3.95 per 100,000. In the 19-year period the average mortality rate was 0.83 per 100,000 per year. The disease was more common in men, in individuals aged 50 to 70 years, and in residents in rural areas engaged in agricultural work. A retrospective case-control study, confirming a significantly higher frequency of MND in farmers and persons living in rural areas, revealed that the disease was more common in the lower social classes to which most unskilled and heavy laborers belong. In addition, a significantly increased risk for MND was found in patients with previous histories of trauma, but confounding variables may account for this association.

Epidemiology of the Guillain-barré syndrome

This review focuses on recent epidemiological findings on Guillain-Barré syndrome regarding incidence, antecedent events related to the disease, prognosis and prognostic indicators, and treatment. Moreover, this review summarizes recent observations on clinical variants of Guillain-Barré syndrome and their relationship with the prevailing clinical presentation of the disease. The epidemiological observations which have advanced the understanding of the pathogenesis of Guillain-Barré syndrome are also discussed.

Studies on epidemiological, clinical, and etiological aspects of ALS disease in Sardinia, Southern Italy.

This investigation was conducted to clarify the epidemiology of ALS disease in Sardinia. During the years 1965–1974, the average annual incidence was found to be 0.64/100,000 inhabitants. On prevalence day, October 24st, 1971, the prevalence rate was 1.56/100,000 inhabitants. A significant male predominance was found, the average annual incidence rates for men and women being 0.88 and 0.40 respectively. The peak in both sexes was reached between 60 and 69 years. ALS distribution in the study area was uniform but its occurrence was significantly higher among agricultural workers (5.28/100,000). ALS started on average at 56.58 years and its duration was 2.5 years, being significantly longer in patients under 40‐years‐old. The distribution of the various clinical forms was: 66 per cent conventional forms, 20 per cent bulbar and 14 per cent pseudo‐polyneuritic. In the bulbar type, a female predominance was found. About 96 per cent of cases were sporadic and 4 per cent familial. Familial cases presented no difference from sporadic cases. Trauma was present in 10.5 per cent of the cases and gastrointestinal disfunction in 13 per cent. This probably reflects some relationship between trauma and ALS, and between malnutrition and ALS. No combination of ALS, dementia and parkinsonism was observed. Dementia was associated with ALS in four cases and Parkinsons disease in one case, separately. The combination of other disease states with ALS in the present study may be simple coincidence.

Cerebrospinal fluid and serum levels and intrathecal production of active matrix metalloproteinase-9 (MMP-9) as markers of disease activity in patients with multiple sclerosis.

In this study, we employed a sensitive activity assay system to measure cerebrospinal fluid (CSF) and serum levels of active matrix metalloproteinase-9 (MMP-9) in 37 relapsing-remitting (RR), 15 secondary progressive (SP) and nine primary progressive (PP) multiple sclerosis (MS) patients, grouped according to clinical and magnetic resonance imaging (MRI) evidence of disease activity. We also studied, as neurological controls, 48 patients with other inflammatory neurological disorders (OIND) and 48 with non-inflammatory neurological disorders (NIND). To assess active MMP-9/TIMP-1 circuit, CSF and serum levels of MMP-9 tissue inhibitor TIMP-1 were quantified by ELISA in the same patient population. CSF mean levels of active MMP-9, CSF active MMP-9/TIMP-1 ratios and intrathecal active MMP-9 synthesis, as indicated by specific index, were more elevated in MS than in NIND (P <0.05, <0.02 and <0.02, respectively), serum active MMP-9/TIMP-1 ratio was higher in MS (P<0.01) and OIND (P<0.02) than in NIND, and serum TIMP-1 concentrations were lower in MS than in NIND (P<0.05). More importantly, serum active MMP-9 mean levels, serum active MMP-9/TIMP-1 ratio and intrathecal production of active MMP-9 were increased in MS patients with clinical (P<0.001, <0.001 and <0.05, respectively) and MRI (P<0.001, <0.001 and <0.02, respectively) disease activity, whereas CSF mean concentrations of active MMP-9 and CSF active MMP-9/TIMP-1 ratio were enhanced only in MS patients with MRI evidence of disease activity (P<0.02 and <0.01, respectively). Altogether, these findings suggest that a shift in MMP-9/TIMP-1 balance towards proteolytic activity of MMP-9 could be relevant in MS immune dysregulation. In addition, our results indicate that CSF and serum levels of active MMP-9 may represent a potential surrogate biomarker for monitoring MS disease activity. In particular, serum active MMP-9/TIMP-1 ratio seems to be a very appropriate indicator of ongoing MS inflammation, since it is easily measurable.