Predictors of survival in a Huntington's disease population from southern Italy.

BACKGROUND: The primary aim of the present study was to determine the survival rates and identify predictors of disease duration in a cohort of Huntington's disease (HD) patients from Southern Italy. METHODS: All medical records of HD patients followed between 1977 and 2008 at the Department of Neurological Sciences of Federico II University in Naples were retrospectively reviewed and 135 patients were enrolled in the analysis. At the time of data collection, 41 patients were deceased (19 males and 22 females) with a mean ± SD age at death of 56.6 ± 14.9 years (range 18-83). RESULTS: The median survival time was 20 years (95% CI: 18.3-21.7). Cox regression analysis showed that the number of CAG in the expanded allele (HR 1.09 for 1 point triplet increase, p=0.002) and age of onset (HR 1.05 for 1 point year increase, p=0.002) were independent and significant predictors of lower survival rates. CONCLUSIONS: We believe that these findings are important for a better understanding of the natural history of the disease and may be relevant in designing future therapeutic trials.

Growth hormone response to arginine test differentiates between two subgroups of Huntington's disease patients.

OBJECTIVE: Huntington's disease (HD) is an autosomal dominant disorder characterised by motor, cognitive and psychiatric disturbances. Several studies have demonstrated that hypothalamic dysfunction is part of the phenotypic spectrum. The aim of the study was to evaluate the growth hormone (GH) response to arginine infusion in a cohort of HD patients, to search for an in vivo biomarker of hypothalamic dysfunction. METHODS: The authors investigated 17 HD patients and 17 age-, sex- and BMI-matched healthy controls. Clinical assessment of patients was performed using the Unified Huntington's Disease Rating Scale motor section and total function capacity. Metabolic and endocrine investigations included total, LDL and HDL cholesterol, basal insulin, GH, insulin-like growth factor 1 (IGF-1), SD Score IGF-1 (SDS IGF-1) and the GH response to arginine stimulation. RESULTS: HD patients showed lower plasma IGF-1 and SDS IGF-1 levels and a higher baseline GH in comparison with control subjects. The arginine test induced a normal GH peak in nine patients (53%; Arg+), whereas the response was absent in the remaining eight (47%; Arg-). Arg+ and Arg- also showed two distinct endocrine/metabolic profiles with differences in insulin and lipid metabolism. CONCLUSION: It remains to be clarified if these two subgroups of patients, according to the GH response to arginine, correspond to different disease stages or to different patterns of neurodegeneration.

The R495W mutation in SPG3A causes spastic paraplegia associated with axonal neuropathy.

Mutations in the SPG3A gene cause a form of pure, early-onset autosomal dominant hereditary spastic paraplegia linked to chromosome 14q. The encoded protein, atlastin, is a putative member of the dynamin superfamily of large GTPases involved in cellular trafficking patterns. We report a new atlastin mutation causing spastic paraplegia in association with axonal neuropathy in an Italian family.

A randomized clinical trial of lithium in multiple system atrophy.

The aim of our study was to test the safety and tolerability of lithium in multiple system atrophy (MSA). The study was randomized, placebo-controlled, and double-blind. The primary endpoint of the study was safety and tolerability. An interim analysis, performed 1 year after the first patient was randomized, showed a higher proportion of trial abandon (P < 0.01) and a higher number of adverse events (P < 0.02) in the lithium group. The trial was stopped by the Data Monitoring Committee. Overall, lithium was not well tolerated, and we do not encourage future studies with lithium in MSA patients.

Insulin sensitivity and early-phase insulin secretion in normoglycemic Huntington's disease patients.

BACKGROUND: Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by an expanded CAG repeat in exon 1 of the HTT gene. There is increasing evidence pointing towards an involvement of the endocrine system in HD. Recent studies, investigating the increased risk of diabetes mellitus and impaired insulin sensitivity and secretion in HD patients, led to contradictory results. OBJECTIVE: To investigate glucose homeostasis in HD. METHODS: Twenty-eight consecutive patients with HD and 28 healthy controls were matched for age, sex, and BMI. Diagnosis of HD was confirmed genetically. Clinical tools for assessment were the Unified Huntington's Disease Rating Scale (UHDRS) motor section and the Total Function Capacity (TFC). Basal metabolic and endocrine investigations and a 2-hour 75-g oGTT were performed. We used the homeostasis model assessment of insulin resistance (HOMA-IR) as index of insulin sensitivity and the insulinogenic index to assess insulin secretion. RESULTS: HD patients did not differ from the controls with respect to fasting plasma glucose, insulin sensitivity and secretion. CAG expansion size, disease stage and duration, or BMI did not influence HOMA-IR and insulinogenic index. Patients showed lower serum glucose (-19%) and insulin levels (-48%) at 30 min and higher serum insulin levels at 90 (+132%) and 120 min (+380%). CONCLUSIONS: Our data do not support an increased risk of diabetes among HD patients although they show glucose regulation abnormalities with a flat glucose curve and delayed insulin peak after oral glucose load.

A randomized controlled clinical trial of growth hormone in amyotrophic lateral sclerosis: clinical, neuroimaging, and hormonal results.

Amyotrophic lateral sclerosis (ALS) is a fatal neurological disease with motor neuron degeneration. Riluzole is the only available treatment. Two-thirds of ALS patients present with growth hormone (GH) deficiency. The aim of this study is to determine if add-on of GH to riluzole, with an individually regulated dose based on Insulin-like growth factor 1 (IGF-I) production, was able to reduce neuronal loss in the motor cortex, reduce mortality, and improve motor function of ALS patients. Patients with definite/probable ALS, in treatment with riluzole, aged 40-85 years, and with disease duration ≤3 years were enrolled. The study was randomized, placebo controlled, and double blind. Before treatment, patients were tested with a GH releasing hormone (GHRH) + arginine test. The initial dose of GH was 2 IU s.c. every other day, and was progressively increased to a maximum of 8 IU. Primary endpoint was N-acetylaspartate/(creatine + choline) (NAA/Cre + Cho) ratio in motor cortex assessed by magnetic resonance spectroscopy performed at months 0, 6, and 12. Secondary endpoints were mortality and ALS functional rating scale revised (ALSFRS-R). The NAA/(Cre + Cho) ratio decreased in all patients who completed the trial. No significant difference was noted between treated and placebo group. At baseline, although IGF-I levels were within the normal range, 73% of patients had GH deficiency, being severe in half of them. Compared with bulbar onset, spinal-onset patients showed more depressed GH response to the GHRH + arginine stimulation test (10.4 ± 7.0 versus 15.5 ± 8.1 ng/mL; p < 0.05). Insulin resistance [homeostasis model assessment of insulin resistance (HOMA-IR)] increased from 2.1 ± 1.0 at baseline to 4.6 ± 1.9 at 12 months (p < 0.001). Insulin-like growth factor (IGF) binding protein 3 (IGFBP-3) decreased from 8,435 ± 4,477 ng/mL at baseline to 3,250 ± 1,780 ng/mL at 12 months (p < 0.001). The results show that GH exerted no effect on cerebral NAA or clinical progression assessed by ALSFRS-R. Two-thirds of ALS patients had GH deficit, with higher levels in the bulbar-onset group. During follow-up, patients showed progressive increase in HOMA-IR and decrease in IGFBP-3 levels.

Suppression of myoclonus in SCA2 by piracetam.

We report on a 30-year-old patient with advanced cerebellar degeneration due to SCA2. He presented with severe myoclonus, which was resistant to conventional therapy and dramatically improved after administration of 12-18 gm/die piracetam. Piracetam may be considered in the treatment of refractory myoclonus in spinocerebellar degenerations.