Prevalence of sleep disturbances in mild cognitive impairment and dementing disorders: a multicenter Italian clinical cross-sectional study on 431 patients.

BACKGROUND/AIMS: Sleep disturbances are common in the elderly and in persons with cognitive decline. The aim of this study was to describe frequency and characteristics of insomnia, excessive daytime sleepiness, sleep-disordered breathing, REM behavior disorder and restless legs syndrome in a large cohort of persons with mild cognitive impairment or dementia. METHODS: 431 consecutive patients were enrolled in 10 Italian neurological centers: 204 had Alzheimer's disease, 138 mild cognitive impairment, 43 vascular dementia, 25 frontotemporal dementia and 21 Lewy body dementia or Parkinson's disease dementia. Sleep disorders were investigated with a battery of standardized questions and questionnaires. RESULTS: Over 60% of persons had one or more sleep disturbances almost invariably associated one to another without any evident and specific pattern of co-occurrence. Persons with Alzheimer's disease and those with mild cognitive impairment had the same frequency of any sleep disorder. Sleep-disordered breathing was more frequent in vascular dementia. REM behavior disorder was more represented in Lewy body or Parkinson's disease dementia. CONCLUSION: A careful clinical evaluation of sleep disorders should be performed routinely in the clinical setting of persons with cognitive decline. Instrumental supports should be used only in selected patients.

Inter-critical and critical excessive daily sleepiness in episodic migraine patients.

The objective of this study was to determine the relationship between sleepiness and migraine in the intercritical period and to evaluate the time course of critical drowsiness during the attacks. One hundred patients fulfilling IHCD 2nd (2004) criteria for migraine without aura were compared to 100 healthy subjects. Habitual excessive daily sleepiness, evaluated by means of Epworth Sleepiness Scale, was not more frequent in patients with episodic migraine than in controls (12% migraineurs vs. 8% controls, NS). The analysis of critical sleepiness by means of Stanford Sleepiness Scale (SSS) revealed a beginning of sleepiness increase before the attack onset, starting 12 h before, a peak of SSS values at the migraine attack onset and then a gradual decrease to reach baseline values only 12-24 h later. Moreover, patients responding to symptomatic drugs showed a greater and faster decrease of critical sleepiness in comparison with non-responder migraineurs; this finding allows excluding the role of medications in promoting critical somnolence and together with critical drowsiness time-course supports the hypothesis that vigilance impairment could be related to migraine pathogenesis.

Tetracycline treatment in patients with progressive external ophthalmoplegia.

BACKGROUND: Tetracyclines could have neuroprotective effects in neuromuscular and neurodegenerative disorders. AIMS OF THE STUDY AND METHODS: Objective of this double-blind randomized pilot study (followed by an adjunctive open-label phase) was to evaluate whether tetracycline (500 mg/day × 14 days/month × 3 months) could be useful in patients (n = 16) with progressive external ophthalmoplegia (PEO). RESULTS: Our results do not formally support any effect of tetracycline on eye motility in PEO. However, some possible protective effects could not be completely ruled out, i.e. a further analysis suggests a possible difference between the tetracycline group and the placebo group, significant at least for oblique motility, when comparing the ratio between the end of the double-blind phase and baseline. Tetracycline could modify some oxidative stress biomarkers in patients with PEO. CONCLUSIONS: Further studies are needed to confirm such effects of tetracycline in patients with PEO, if any, and to clarify the mechanisms of action for antioxidant effects of tetracyclines in mitochondrial disorders and other diseases.

Dysfunction of the magnocellular stream in Alzheimer's disease evaluated by pattern electroretinograms and visual evoked potentials.

BACKGROUND: Visuo-spatial disturbances could represent a clinical feature of early stage Alzheimer's disease (AD). The magnocellular (M) pathway has anatomo-physiological characteristic which make it more suitable for detecting form, motion and depth compared with parvocellular one (P). OBJECTIVE: Aim of our study was to evaluate specific visual subsystem involvement in a group of AD patients, recording isoluminant chromatic and luminance pattern electroretinograms and pattern visual evoked potentials. MATERIAL AND METHODS: data were obtained from 15 AD patients (9 females and 6 males, mean age+/-1SD: 77.6+/-4.01 years) not yet undergoing any treatment, and from 10 age-matched healthy controls. Diagnosis of probable AD was clinically and neuroradiologically established. PERGs were recorded monocularly in response to equiluminant red-green (R-G), blue-yellow (B-Y) and luminance yellow-black (Y-Bk) horizontal square gratings of 0.3c/deg and 90% contrast, reversed at 1Hz. VEPs were recorded in response to full-field (14 deg) equiluminant chromatic R-G, B-Y and luminance Y-Bk sinusoidal gratings of 2c/deg, presented in onset (300ms)-offset (700ms) mode, at the contrast levels of 90%. RESULTS: All data were retrieved in terms of peak-amplitude and latency and assessed using the Student's t-test for paired data. Temporal differences of PERGs and VEPs, evoked by Y-Bk grating in AD patients compared with controls, suggest a specific impairment of the magnocellular stream. CONCLUSIONS: Our study support the hypothesis that the impairment of the PERGs and VEPs arising from the magnocellular streams of visual processing may indicate a primary dysfunction of the M-pathways in AD.

Clinical trials for neuroprotection in ALS.

Owing to uncertainty on the pathogenic mechanisms underlying motor neuron degeneration in amyotrophic lateral sclerosis (ALS) riluzole remains the only available therapy, with only marginal effects on disease survival. Here we review some of the recent advances in the search for disease-modifying drugs for ALS based on their putative neuroprotective effetcs. A number of more or less established agents have recently been investigated also in ALS for their potential role in neuroprotection and relying on antiglutamatergic, antioxidant or antiapoptotic strategies. Among them Talampanel, beta-lactam antibiotics, Coenzyme Q10, and minocycline have been investigated. Progress has also been made in exploiting growth factors for the treatment of ALS, partly due to advances in developing effective delivery systems to the central nervous system. A number of new therapies have also been identified, including a novel class of compounds, such as heat-shock protein co-inducers, which upregulate cell stress responses, and agents promoting autophagy and mitochondriogenesis, such as lithium and rapamycin. More recently, alterations of mRNA processing were described as a pathogenic mechanism in genetically defined forms of ALS, as those related to TDP-43 and FUS-TLS gene mutations. This knowledge is expected to improve our understanding of the pathogenetic mechanism in ALS and developing more effective therapies.

Sleep disturbances in elderly subjects: an epidemiological survey in an Italian district.

OBJECTIVES: Disturbed sleep is common in elderly people and has been related to comorbidities. The aim of this study was to evaluate the prevalence of sleep problems and their relationship with chronic disease in an elderly population. MATERIALS AND METHODS: The whole population of subjects aged more than 65 years, in the municipality of Vecchiano, Pisa was considered as eligible and underwent a clinical interview and a questionnaire about insomnia, sleepiness, snoring and sleep apnea. A model of logistic regression was applied to the data. RESULTS: The participation rate was 60.3% (1427 subjects). Insomnia was observed in 44.2% of our population, while sleepiness in 31.3%, snoring in 47.2% and sleep apnea in 9.0%. The most common diseases associated with sleep symptoms were depression, cognitive decline and diabetes. CONCLUSIONS: Our results confirm that sleep problems are very common in elderly subjects and closely related to medical and psychiatric illnesses.

Clinical Recovery despite Cortical Cerebral and Cerebellar Damage in Heat Stroke.

The prognosis of heat stroke has considerably improved with a mortality rate drop to 10% when therapeutic measurements including external cooling and aggressive rehydration are adopted. The role of imaging in predicting prognosis is uncertain. Some noted that development of cortical cerebellar atrophy is associated with development of a pancerebellar syndrome, while others suggested that evidence of cerebral cortical damage due to hypoxic-ischemic injury implies a poor prognosis. We observed a 17-year-old female who presented with lost of consciousness and seizure while jogging on a hot summer day followed by multi-organ failure. Brain MRI revealed a symmetric area of T2 hyperintensity and decreased diffusion in the cortical gyri of the frontal lobes. The patient made a complete recovery. MRI two years later showed disappearance of signal changes in the frontal cortex, but progressive atrophy of the cerebellum which was clinically silent. Our observation challenges the view of a close correlation between the imaging findings and prognosis in heat stroke.

Does sphenopalatine endoscopic ganglion block have an effect in paroxysmal hemicrania? A case report.

The authors report the case of a 69-year-old woman suffering from paroxysmal hemicrania (PH), intolerant to indomethacin and resistant to multiple therapies, in which sphenopalatine endoscopic ganglion block (SPG) dramatically modified the clinical outcome. SPG blockade could be considered a reasonable alternative in drug-resistant PH cases where indomethacin is contraindicated.

Behavioural sensitisation during dopamine replacement therapy in Parkinson's disease is reminiscent of the addicted brain.

The intermittent oral intake of the dopamine (DA) precursor L-3,4-dihydroxyphenylalanine (L-DOPA) is the classic therapy of Parkinson's disease (PD). In this way, the drug precursor can be metabolised into the active neurotransmitter DA. Although this occurs throughout the brain, the therapeutic relief is believed to be due to restoring extracellular DA levels within the dorsal striatum (more in the putamen than the caudate nucleus) which lacks endogenous DA as a consequence of the disease process. However, differing from physiological DA transmission, this therapeutic pattern leads to abnormal peaks of non-synaptic DA, which are supposed to trigger behavioural sensitisation expressed as abnormal involuntary movements. A similar pattern of abnormal DA stimulation occurs during methamphetamine (METH) intake. In the present review we will provide evidence showing the similarities between METH- and L-DOPA-induced DA stimulation with an intact and denervated striatum respectively. This comparison will encompass various features; the timing, the areas and the amount of extracellular DA levels which reveal surprising homologies. Such an overlapping between L-DOPA in PD and METH will be further analysed to critically assess the commonalities concerning the following points: abnormal receptor stimulation, recruitment of altered transduction pathways, abnormal gene expression, alterations in the phenotype of striatal neurons, and the establishment of behavioural sensitisation which appear as distinct phenomena (i.e. abnormal involuntary movements in PD and drug addiction in METH abuse); nonetheless, this may also lead to common behavioural alterations (METH-like addictive behaviours in PD patients during the course of DA replacement therapy in subsets of PD patients).

Mitochondria, mitochondrial DNA and Alzheimer's disease. What comes first?

To date, the beta amyloid (Abeta) cascade hypothesis remains the main pathogenetic model of Alzheimer's disease (AD), but its role in the majority of sporadic AD cases is unclear. The mitochondria play central role in the bioenergetics of the cell and apoptotic cell death. In the past 20 years research has been directed at clarifying the involvement of mitochondria and defects in mitochondrial oxidative phosphorylation in late-onset neurodegenerative disorders, including AD. Morphological, biochemical and genetic abnormalities of the mitochondria in several AD tissues have been reported. Impaired mitochondrial respiration, particularly COX deficiency, has been observed in brain, platelets and fibroblasts of AD patients. The "mitochondrial cascade hypothesis" could explain many of the biochemical, genetic and pathological features of sporadic AD. Somatic mutations in mitochondrial DNA (mtDNA) could cause energy failure, increased oxidative stress and accumulation of Abeta, which in a vicious cycle reinforces the mtDNA damage and the oxidative stress. Despite the evidence of mitochondrial dysfunction in AD, no causative mutations in the mtDNA have been detected so far. Indeed, results of studies on the role of mtDNA haplogroups in AD are controversial. In this review we discuss the role of the mitochondria in the cascade of events leading to AD, and we will try to provide an answer to the question "what comes first".

Transcranial magnetic stimulation mapping: a model based on spline interpolation.

Transcranial magnetic stimulation (TMS) is a non-invasive method to investigate motor pathways and to create a map of the somatotopical organization of the motor cortex: ordinary mapping procedures requires a focal brain stimulation over different spots of the scalp and electromyographic (EMG) recording from a muscle. Finding an appropriate and a valid visual representation of collected data is a crucial step in research and clinical field to allow a relatively fast, intra- and inter-patient comparison of motor cortex mapping. Aim of this study was to develop and to validate a method to map cortical representation of an intrinsic hand muscle (abductor digiti minimi, ADM) using a two-dimensional spline interpolation of EMG peak amplitudes obtained with TMS. The interpolated model will result in a graphical colour-scaled representation of the motor cortex for the investigated muscle; fitted model was finally validated by comparing derived parameters with those directly measured to ensure the strength and reliability of the model. Ten healthy volunteers (mean age+/-S.D.: 35.3+/-4.7 years, 4 males and 6 females) were enrolled in the study. Transcranial stimulation was performed by placing a figure-of-eight coil over a predefined grid on the scalp of the subject. EMG responses were recorded from the right abductor digiti minimi (ADM): averaged EMG peak amplitudes obtained at each node were then used to perform spline interpolation and to derive other parameters like center of gravity (CoG). Arithmetical mean of all resting motor threshold at the hotspot was 50.6+/-3.4% of the maximal stimulator output. Average amplitude at the hotspot was 1.72+/-0.80 mV and its coordinates, expressed as median, were x=4.5 cm and y=0.0 cm. Mean CoG was located at x=4.86+/-0.57 cm and y=0.35+/-0.10 cm. Mean interpolated peak coordinates for ADM were xf=4.86+/-0.58 cm and yf=0.36+/-0.12 cm, while mean fitted peak amplitude was 0.87+/-0.47 mV. Results suggest how it is possible to map the primary motor cortex using two-dimensional spline interpolation of peak-to-peak amplitudes obtained by single pulse TMS delivered on several scalp positions, which will result in a smooth, easy to read, colour-scaled map. However, like other visual representation modalities, the interpolation should become complementary to traditional methods and not a substitute of a precise and accurate cortical motor mapping.

CSF phosporylated TAU protein levels correlate with cerebral glucose metabolism assessed with PET in Alzheimer's disease.

One major goal of drug development would be the establishment of biomarkers as objective indicators of normal biological and pathogenetic processes, or pharmacological response to a therapeutic intervention. A potential approach is to investigate proteins in CSF linked to key neuropathological features of Alzheimer's disease (AD). Recently CSF phosphorylated-Tau (p-Tau) levels have been reported to reflect neurofibrillary changes within the brain of patients with AD, however the use of serial CSF investigations in order to monitor the disease progression is not applicable. PET with FDG reveals characteristic patterns in AD patients, however so far no correlation between in vivo metabolic information and pathological features has been reported. In the present study, we tested whether CSF Tau levels correlate with metabolic rate for glucose consumption in a cohort of 28 AD patients. We found a statistically significative correlation between both CSF total and p-TAU protein and relative metabolic indexes obtained from 18FDG-PET scans in parietal, temporal and occipital lobes bilaterally. These results indicate the existence of a correlation between impairment of cerebral metabolism, estimated throughout FDG-PET, and CSF Tau protein levels.

Diffusion-weighted imaging in patients with progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the central nervous system due to JC polyoma virus infection of oligodendrocytes. PML develops in patients with impaired T-cell function as occurs in HIV, malignancy or immunosuppressive drugs users. Until now no imaging methods have been reported to correlate with clinical status. Diffusion-weighted imaging (DWI) is a robust MRI tool in investigating white matter architecture and diseases. The aim of our work was to assess diffusion abnormalities in focal white matter lesions in patients with PML and to correlate the lesion load measured with conventional MRI and DWI to clinical variables. We evaluated eight patients with a biopsy or laboratory-supported diagnosis of PML. All patients underwent MRI including conventional sequences (fluid attenuated inversion recovery-FLAIR) and DWI. Mean diffusivity (MD) maps were used to quantify diffusion on white matter lesions. Global lesion load was calculated by manually tracing lesions on FLAIR images, while total, central core and peripheral lesion loads were calculated by manually tracing lesions on DWI images. Lesion load obtained with the conventional or DWI-based methods were correlated with clinical variables such as disease duration, disease severity and survival. White matter focal lesions are characterized by a central core with low signal on DWI images and high MD (1.853 x 10(-3) mm2/s), surrounded by a rim of high signal intensity on DWI and lower MD (1.1 x 10(-3) mm2/s). The MD value of normal-appearing white matter is higher although not statistically significant (0.783 x 10(-3) mm2/s) with respect to control subjects (0.750 x 10(-3) mm2/s). Inter-rater correlations of global lesion load between FLAIR (3.96%) and DWI (3.43%) was excellent (ICC=0.87). Global lesion load on FLAIR and DWI correlates with disease duration and severity (respectively, p=0.037, p=0.0272 with Karnofsky scale and p=0.0338 with EDSS on FLAIR images; p=0.043, p=0.0296 with Karnofsky scale and p=0.0365 with EDSS on DW images). Central core lesion load on DWI correlates with disease duration and severity (respectively p=0.043, p=0.0103 with Karnofsky scale and p=0.0112 with EDSS), while peripheral lesion load does not correlate with any clinical variable. The global lesion load in PML correlates with disease duration and severity. DWI images, which can distinguish within lesions a central core from a peripheral rim, reveal that a larger central core component correlates to a worsened clinical status and longer disease duration. On the other hand the peripheral rim lesion load visualized on DWI images does not correlate with clinical variables and does not achieve obtaining further prognostic information with respect to conventional imaging.

Impairment of GH secretion in amyotrophic lateral sclerosis is not affected by riluzole treatment.

Amyotrophic lateral sclerosis (ALS), the most common motor neurone disorder in human adults, is characterized by selective and progressive degeneration of upper and lower motor neurones in the central nervous system. The main currently available drug for ALS treatment is riluzole, a compound that acts through inhibition of glutamate release, postsynaptic receptor activation, and voltage-sensitive channel inhibition. GH secretion, evaluated by GHRH+arginine (ARG) test, has recently been reported to be impaired in most untreated ALS patients. The aim of the present study was to evaluate whether riluzole administration could interfere with GH secretion and therefore with the diagnosis of adult GH deficiency. Ten patients (6 males, 4 females, mean age 59+/-11 yr) were studied performing GHRH+ARG test before and 3 months after starting riluzole treatment (100 mg/day). Blood samples for GH were collected at baseline, at 30 and 60 min. Both before and during riluzole treatment, 5 patients showed GH deficiency and 5 patients had a normal GH response according to body mass index (BMI). Mean peak GH levels were similar before and during riluzole treatment (13.4+/-10 vs 14.2+/-10.1 microg/l, p=ns). No significant correlation was observed between GH concentrations and age, BMI, disease duration, severity or clinical (bulbar/spinal) form. In conclusion, the present data confirm that GH secretion is impaired in a new series of ALS patients and indicate that riluzole treatment does not interfere with GH secretion. Thus, evaluation of GH secretion in ALS patients can also be performed without withdrawing riluzole treatment.