Pietro Guaraldi

University of Bologna, Bolonia, Emilia-Romagna, Italy

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Publications (21)51.6 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Circadian rhythms were recently proposed as a measure of physiological state and prognosis in disorders of consciousness (DOC). So far, melatonin regulation was never assessed in vegetative state (VS). Aim of our research was to investigate the nocturnal melatonin levels and light-induced melatonin suppression in a cohort of VS patients. We assessed six consecutive patients (four men, age 33.3 ± 9.3 years) with post-traumatic VS and nine age-matched healthy volunteers (five men, age 34.3 ± 8.9 years) on two consecutive nights: one baseline and one light exposure night. During baseline, night subjects were in bed in a dim (<5 lux) room from 10 pm to 8 am. Blood samples were collected hourly 00:30-3:30 am (00:30 = MLT1; 1:30 = MLT2; 2:30 = MLT3; and 3:30 = MLT4). Identical setting was used for melatonin suppression test night, except for the exposure to monochromatic (470 nm) light from 1:30 to 3:30 am. Plasma melatonin levels were evaluated by radioimmunoassay. Magnitude of melatonin suppression was assessed by melatonin suppression score (caMSS) and suppression rate. We searched for group differences in melatonin levels, differences between repeated samples melatonin concentrations during baseline night and light exposure night, and light-induced suppression of melatonin secretion. During baseline night, controls showed an increase of melatonin (MLT4 vs MLT1, p = 0.037), while no significant changes were observed in VS melatonin levels (p = 0.172). Baseline night MLT4 was significantly lower in VS vs controls (p = 0.036). During light-exposure night, controls displayed a significant suppression of melatonin (MLT3 and MLT4 vs MLT2, p = 0.016 and 0.002, respectively), while VS patients displayed no significant changes. The magnitude of light-induced suppression of melatonin levels was statistically different between groups considering control adjusted caMSS (p = 0.000), suppression rate (p = 0.002) and absolute percentage difference (p = 0.012). These results demonstrate for the first time that VS patients present an alteration in night melatonin secretion and reduced light-induced melatonin suppression. These findings confirm previous studies demonstrating a disruption of the circadian system in DOC and suggest a possible benefit from melatonin supplementation in VS.
    Chronobiology International 03/2014; · 4.35 Impact Factor
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    ABSTRACT: Many studies have addressed the relation between orthostatic hypotension (OH) and cognitive impairment (CI) in the elderly, in mild cognitive impairment, vascular and neurodegenerative dementias and movement disorders, such as Parkinson's disease. However, results concerning both the increased coexistence of the two conditions and their causal relationship remain controversial. According to the literature three hypotheses can be formulated on the relation between OH and CI. In neurodegenerative disease, OH and CI may result from a common pathological process which affects areas involved in both cognition and cardiovascular autonomic control. Alternatively, OH may lead to cerebral hypoperfusion which is supposed to play a role in the development of CI. Finally, recent data suggest that CI should probably be considered more a transient symptom of OH than a chronic effect. This study reviews the literature reports on the relationship between OH and CI, and emphasises the need for longitudinal studies designed to investigate this topic.
    Neurological Sciences 03/2014; · 1.41 Impact Factor
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    ABSTRACT: aims of the current study were 1) to evaluate global cognitive function in patients with autonomic failure (AF) of peripheral origin and 2) to investigate the effect of a documented fall in blood pressure (BP) fulfilling the criteria for orthostatic hypotension (OH) on cognitive performances. we assessed 12 consecutive patients (10 males, 68±7 years old) with pure AF (PAF) or autoimmune autonomic neuropathy (AAN) and 12 age- and gender-matched controls. All patients had no clinical signs of central nervous system involvement and normal brain CT/MRI scan. Cognitive function was assessed on two consecutive days in 3 conditions: on day 1, while sitting, by means of a comprehensive battery of neuropsychological tests; on day 2, while tilted (HUT) and during supine rest (supine) in a randomized manner. BP and heart rate (HR) were continuously recorded non-invasively for the whole duration of the examination. patients with PAF or AAN displayed a preserved global cognitive function while sitting. However, compared to supine assessment, during HUT patients scored significantly worse during the Trail Making Test A and B, Barrage test, Analogies test, Immediate Visual Memory, Span Forward and Span Backward test. Pathological scores, with regard to Italian normative range values, were observed only during HUT in the Barrage test and in the Analogies test in 3 and 6 patients respectively. On the contrary, in healthy controls, results to neuropsychological tests were not significantly different, during HUT compared to supine rest. these data demonstrate that patients with PAF and AAN present a normal sitting global cognitive evaluation. However, their executive functions worsen significantly during the orthostatic challenge, possibly because of transient frontal lobes hypoperfusion.
    PLoS ONE 01/2014; 9(1):e85020. · 3.73 Impact Factor
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    ABSTRACT: Background and Objectives The autonomic nervous system (ANS) regulates involuntary body functions and is commonly evaluated by measuring reflex responses of systolic and diastolic blood pressure (BP) and heart rate (HR) to physiological and pharmacological stimuli. However, BP and HR values may not sufficient be to explain specific ANS events and other parameters like the electrocardiogram (ECG), BP waves, the respiratory rate and the electroencephalogram (EEG) are mandatory. Although ANS behaviour and its response to stimuli are well-known, their clinical evaluation is often based on individual medical training and experience. As a result, ANS laboratories have been customized, making it impossible to standardize procedures and share results with colleagues. The aim of our study was to build a powerful versatile instrument easy-to-use in clinical practice to standardize procedures and allow a cross-analysis of all the parameters of interest for ANS evaluation. Methods The new ANScovery System developed by neurologists and technicians is a two-step device: 1) integrating physiological information from different already existing commercial modules, making it possible to cross-analyse, store and share data; 2) standardizing procedures by an innovative tutor monitor able to guide the patient throughout ANS testing. Results and Conclusions The daily use of the new ANScovery System in clinical practice has proved it is a versatile easy to use instrument. Standardization of the manoeuvres and step-by-step guidance throughout the procedure avoid repetitions and allow intra and inter-patient data comparison.
    Computer Methods and Programs in Biomedicine. 01/2014;
  • Sleep Medicine 10/2013; · 3.49 Impact Factor
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    ABSTRACT: Multiple system atrophy (MSA) is a neurodegenerative disease characterised by cardiovascular autonomic failure and/or urinary dysfunctions, associated with parkinsonism, cerebellar and/or corticospinal signs, usually leading to death after an average of 7 years. We describe the disease course of five patients diagnosed with probable MSA (4 with predominant parkinsonism and 1 with predominant cerebellar ataxia) who survived for more than 15 years and were followed throughout the disease course at our department. Cardiovascular autonomic dysfunction of any severity occurred late (mean latency from disease onset 9.4 ± 5 years) in this subgroup of MSA patients. The time of involvement of the urogenital system was more variable (from 0 to 14 years after disease onset) and manifested with symptoms of storage disorders (urinary urgency, frequency and incontinence) and erectile dysfunction in men. Conversely complains suggestive of urinary voiding dysfunction (incomplete bladder emptying and urinary retention) were not recorded and patients required catheterization only late in the disease course. In conclusion, our study showed that late onset of both cardiovascular autonomic failure and urinary voiding disorders may be positive prognostic factors in MSA irrespective of the MSA subtype.
    Neurological Sciences 06/2013; · 1.41 Impact Factor
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    ABSTRACT: Objective of this study was to evaluate the acute cardiovascular and respiratory effects of switching on the deep brain stimulation in the follow up of nine Parkinson's disease patients with subthalamic nucleus stimulation and six cluster headache patients with posterior hypothalamic area stimulation. Systolic and diastolic blood pressure, heart rate, and respiratory rate were monitored continuously during supine rest in both groups. Each patient was assessed in two conditions: resting supine with stimulator off and with stimulator on. In supine resting condition switching on the DBS induced no significant changes (p>0.05) in systolic and diastolic blood pressure as well as in heart rate and respiratory rate, in both groups of patients, either taking 1 min or 10 heartbeats as a sample for analysis. Switching on the DBS does not modify heart rate, blood pressure nor respiratory rate in both Parkinson and cluster headache patients under resting conditions.
    Autonomic neuroscience: basic & clinical 01/2012; 166(1-2):81-4. · 1.82 Impact Factor
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    ABSTRACT: The exact clinical and prognostic significance and the therapeutic implications of asystole induced by head-up tilt test are still a matter of debate. We assessed, by means of a semi-structured interview, the long-term outcome of cardioinhibitory syncope in all the patients who presented a tilt-induced sinus arrest of more than 3 s in our Autonomic Unit between 1996 and 2010. Although syncopal recurrences were common, tilt-induced asystole did not imply a poor prognosis in terms of death or major therapeutic procedures.
    Clinical Autonomic Research 12/2011; 22(3):155-60. · 1.48 Impact Factor
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    ABSTRACT: Morvan chorea is an antibody-mediated limbic encephalopathy characterized by severe insomnia, mental confusion, hallucinations, enacted dreams, hyperhidrosis, and neuromyotonia. In a 78 years old man presenting with progressive insomnia apathy and depression, a video-polysomnogram documented enacted dreams mimicking daily life activity (oneiric stupor). This finding led us to perform a search for serum antibodies to voltage-gated K+ channels, which was positive. A diagnosis of Morvan chorea was done. The patient underwent plasma exchange with complete resolution of the clinical picture. Oneiric stupor may represent a useful precocious diagnostic marker in Morvan chorea.
    Sleep Medicine 12/2011; 12(10):1041-3. · 3.49 Impact Factor
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    ABSTRACT: Agrypnia excitata (AE) is a syndrome characterized by the inability to sleep associated with a generalized motor and autonomic over-activation. AE is caused by a thalamo-limbic system dysfunction and comprises three different conditions: Fatal Familial Insomnia (FFI), Delirium Tremens (DT), and Morvan Syndrome (MS). Oneiric Stupor episodes (OS) are the peculiar motor behaviour of AE. During OS patients perform simple automatic gestures mimicking daily-life activities. This paper is the first description of the different characteristics of OS in two patients with MS and another with FFI, emphasizing the specific clinical features that reliably differentiate OS from REM sleep behaviour disorders.
    Sleep Medicine 12/2011; 12 Suppl 2:S64-7. · 3.49 Impact Factor
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    ABSTRACT: In previous studies, addressing the association between orthostatic hypotension and cognitive decline, patients underwent neuropsychological evaluation in sitting position, and blood pressure values and cognition were not measured concurrently. Furthermore, no studies assessed the acute effects of orthostatic hypotension on cognitive performances. The aim of our study was to evaluate the effect of a documented fall in systolic blood pressure (SBP) of at least 20 mmHg on a battery of cognitive tests in patients with neurogenic orthostatic hypotension. Ten consecutive patients with neurogenic orthostatic hypotension, normal brain imaging, and a normal Mini Mental State Examination in supine position were enrolled in the study. Patients underwent a detailed neuropsychological assessment (Brief Mental Deterioration battery and computerized tests) over two test sessions: the first while tilted to an angle able to cause a fall of at least 20 mmHg in SBP; the second while supine, after 30 min of rest. Parallel forms of the tests were presented on each testing session. Patients scored significantly worse in the visual search test, analogies test, immediate visual memory, and the measure of global cognitive functioning of Brief Mental Deterioration battery during the orthostatic challenge compared to the supine position. Orthostatic hypotension was associated with a significant worsening of cognitive performances, affecting both global cognitive functioning and specific tasks, mainly exploring executive functions. The assessment of cognitive function in patients with neurogenic orthostatic hypotension should be performed considering the body's position of the subject.
    Neurological Sciences 09/2011; 33(2):469-73. · 1.41 Impact Factor
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    ABSTRACT: We evaluated the autonomic control of the cardiovascular system and the skin innervation of a patient from a new Italian family with a genetically proven diagnosis of adult-onset autosomal dominant leukodystrophy (ADLD) due to lamin B1 gene duplication. Cardiovascular reflexes and pharmacological assessment indicated a selective sympathetic failure, sparing cardiovagal function. Microneurography revealed absent sympathetic activity. The evaluation of autonomic innervation of skin annexes showed severely depleted and morphologically abnormal noradrenergic dopamine-β-hydroxylase (DβH) immunoreactive fibres with preserved cholinergic vasoactive intestinal polypeptide (VIP) immunoreactive fibres. This peculiar autonomic dysfunction may represent a hallmark for ADLD.
    Autonomic neuroscience: basic & clinical 01/2011; 159(1-2):123-6. · 1.82 Impact Factor
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    ABSTRACT: Narcolepsy with cataplexy (NC) is a sleep disorder caused by the loss of the hypothalamic neurons producing hypocretin. The clinical hallmarks of the disease are excessive daytime sleepiness, cataplexy, other rapid eye movement (REM) sleep phenomena, and a fragmented wake-sleep cycle. Experimental data suggest that the hypocretin system is involved primarily in the circadian timing of sleep and wakefulness but also in the control of other biological functions such as thermoregulation. The object of this study was to determine the effects of the hypocretin deficit and of the wake-sleep cycle fragmentation on body core temperature (BcT) modulation in a sample of drug-free NC patients under controlled conditions. Ten adult NC patients with low cerebrospinal fluid (CSF) hypocretin levels (9 men; age: 38 ± 12 yrs) were compared with 10 healthy control subjects (7 men; age: 44.9 ± 12 yrs). BcT and sleep-wake cycle were continuously monitored for 44 h from 12:00 h. During the study, subjects were allowed to sleep ad libitum, living in a temperature- and humidity-controlled room, lying in bed except when eating, in a light-dark schedule (dark [D] period: 23:00-07:00 h). Sleep structure was analyzed over the 24-h period, the light (L) and the D periods. The wake-sleep cycle fragmentation was determined by calculating the frame-shift index (number of 30-s sleep stage shifts occurring every 15 min) throughout the 44-h study. The analysis of BcT circadian rhythmicity was performed according to the single cosinor method. The time-course changes in BcT and in frame-shift index were compared between narcoleptics and controls by testing the time × group (controls versus NC subjects) interaction effect. The state-dependent analysis of BcT during D was performed by fitting a mixed model where the factors were wake-sleep phases (wake, NREM stages 1 and 2, slow-wave sleep, and REM sleep) and group. The results showed that NC patients slept significantly more than controls during the 24 h due to a higher representation of any sleep stage (p < .001) during L, whereas the total amount of night sleep and its architecture were comparable in the two groups. Wake-sleep fragmentation was higher (p < .001) in NC subjects especially during L. Despite these differences, mesor (24-h mean), amplitude, and acrophase (peak time) of BcT circadian rhythm were comparable in narcoleptics and controls, and no between-group differences were detected in the time-course changes and in the state-dependent modulation at night of BcT. These data indicate that the hypocretin deficit in drug-free NC patients and their altered wake-sleep cycle couple with an intact modulation of BcT.
    Chronobiology International 09/2010; 27(8):1596-608. · 4.35 Impact Factor
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    ABSTRACT: During maximal breath-holding six healthy elite breath-hold divers, after an initial "easy-going" phase in which cardiovascular changes resembled the so-called "diving response", exhibited a sudden and severe rise in blood pressure during the "struggle" phase of the maneuver. These changes may represent the first tangible expression of a defense reaction, which overrides the classic diving reflex, aiming to reduce the hypoxic damage and to break the apnea before the loss of consciousness.
    Clinical Autonomic Research 09/2009; 19(6):363-6. · 1.48 Impact Factor
  • Sleep Medicine - SLEEP MED. 01/2009; 10.
  • Autonomic Neuroscience-basic & Clinical - AUTON NEUROSCI-BASIC CLIN. 01/2009; 149(1):67-68.
  • Autonomic Neuroscience-basic & Clinical - AUTON NEUROSCI-BASIC CLIN. 01/2009; 149(1):70-71.
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    ABSTRACT: The objective of this study was to determine the cardiovascular effects of chronic stimulation of the posterior hypothalamic area (PHA) in cluster headache (CH) patients. Systolic and diastolic blood pressure (SBP, DBP), cardiac output, total peripheral resistance (TPR), heart rate (HR) and breathing were monitored at supine rest and during head-up tilt test (HUTT), Valsalva manoeuvre, deep breathing, cold face test and isometric handgrip in eight drug-resistant chronic CH patients who underwent monolateral electrode implantation in the PHA for therapeutic purposes. Autoregressive power spectral analysis (PSA) of HR variability (HRV) was calculated at rest and during HUTT. Each subject was studied before surgery (condition A) and after chronic deep brain stimulation (DBS) of PHA (condition B). Baseline SBP, DBP, HR and cardiovascular reflexes were normal and similar in both conditions. With respect to condition A, DBP, TPR and the LF/HF obtained from the PSA of HRV were significantly (P < 0.05) increased during HUTT in condition B. In conclusion, chronic DBS of the PHA in chronic CH patients is associated with an enhanced sympathoexcitatory drive on the cardiovascular system during HUTT.
    European Journal of Neurology 09/2007; 14(9):1008-15. · 4.16 Impact Factor
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    ABSTRACT: Of 41 HIV-infected patients with facial lipoatrophy who underwent autologous fat transplantation, disfiguring facial lipohypertrophy at the graft site occurred at the same time as recurrent fat accumulation at the tissue harvest site in 4 patients who had had fat transferred from the dorsocervical fat pad or from subcutaneous abdominal tissue.
    Clinical Infectious Diseases 02/2005; 40(2):e13-5. · 9.37 Impact Factor
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    ABSTRACT: Headache is generally regarded as a symptom of high blood pressure in spite of conflicting opinions on the association of headache and arterial hypertension. Most studies have shown that mild chronic hypertension and headache are not associated and this demonstration needs to be implemented in clinical practice. Whether moderate hypertension predisposes to headache remains controversial, but there is little evidence that it does. Headaches caused by significant disturbances in arterial pressure are included in the section "Headache attributed to a disorders of homeostasis" (code 10.3) of the 2nd edition of the International Classification of Headache disorders.
    Neurological Sciences 11/2004; 25 Suppl 3:S132-4. · 1.41 Impact Factor

Publication Stats

88 Citations
51.60 Total Impact Points

Institutions

  • 2009–2014
    • University of Bologna
      • • Department of Biomedical Science and Neuromotor Sciences DIBINEM
      • • Department of Biological, Geological and Environmental Sciences BiGeA
      Bolonia, Emilia-Romagna, Italy
  • 2012
    • Università degli Studi di Palermo
      Palermo, Sicily, Italy
  • 2004–2007
    • Università degli Studi di Modena e Reggio Emilia
      Modène, Emilia-Romagna, Italy