Mortality Attributable to Bloodstream Infections Caused by Different Carbapenem-Resistant Gram-Negative Bacilli: Results From a Nationwide Study in Italy (ALARICO Network).

BACKGROUND: Our aim was to analyze mortality attributable to carbapenem-resistant (CR) gram-negative bacilli (GNB) in patients with bloodstream infections (BSIs). METHODS: Prospective multicentric study including patients with GNB-BSI from 19 Italian hospitals (June 2018-January 2020). Patients were followed-up to 30 days. Primary outcomes were 30-day mortality and attributable mortality. Attributable mortality was calculated in the following groups: Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacterales, metallo-ß-lactamases (MBL)-producing Enterobacterales, CR-Pseudomonas aeruginosa (CRPA), CR-Acinetobacter baumannii (CRAB). A multivariable analysis with hospital fixed-effect was built to identify factors associated with 30-day mortality. Adjusted OR (aORs) were reported. Attributable mortality was calculated according to the DRIVE-AB Consortium. RESULTS: Overall, 1276 patients with monomicrobial GNB BSI were included: 723/1276 (56.7%) carbapenem-susceptible (CS)-GNB, 304/1276 (23.8%) KPC-, 77/1276 (6%) MBL-producing CRE, 61/1276 (4.8%) CRPA, and 111/1276 (8.7%) CRAB BSI. Thirty-day mortality in patients with CS-GNB BSI was 13.7% compared to 26.6%, 36.4%, 32.8% and 43.2% in patients with BSI by KPC-CRE, MBL-CRE, CRPA and CRAB, respectively (P < .001). On multivariable analysis, age, ward of hospitalization, SOFA score, and Charlson Index were factors associated with 30-day mortality, while urinary source of infection and early appropriate therapy resulted protective factors. Compared to CS-GNB, MBL-producing CRE (aOR 5.86, 95% CI 2.72-12.76), CRPA (aOR 1.99, 95% CI 1.48-5.95) and CRAB (aOR 2.65, 95% CI 1.52-4.61) were significantly associated with 30-day mortality. Attributable mortality rates were 5% for KPC-, 35% for MBL, 19% for CRPA, and 16% for CRAB. CONCLUSIONS: In patients with BSIs, carbapenem-resistance is associated with an excess of mortality, with MBL-producing CRE carrying the highest risk of death.

Reduced threshold for inhibitory homeostatic responses in migraine motor cortex? A tDCS/TMS study.

BACKGROUND AND OBJECTIVE: Neurophysiological studies in migraine have reported conflicting findings of either cortical hyper- or hypoexcitability. In migraine with aura (MwA) patients, we recently documented an inhibitory response to suprathreshold, high-frequency repetitive transcranial magnetic stimulation (hf-rTMS) trains applied to the primary motor cortex, which is in contrast with the facilitatory response observed in the healthy subjects. The aim of the present study was to support the hypothesis that in migraine, because of a condition of basal increased cortical responsivity, inhibitory homeostatic like mechanisms of cortical excitability could be induced by high magnitude stimulation. For this purpose, the hf-rTMS trains were preconditioned by transcranial direct current stimulation (tDCS), a noninvasive brain stimulation technique able to modulate the cortical excitability state. METHODS: Twenty-two MwA patients and 20 patients with migraine without aura (MwoA) underwent trains of 5-Hz repetitive transcranial magnetic stimulation at an intensity of 130% of the resting motor threshold, both at baseline and after conditioning by 15 minutes of cathodal or anodal tDCS. Motor cortical responses to the hf-rTMS trains were compared with those of 14 healthy subjects. RESULTS: We observed abnormal inhibitory responses to the hf-rTMS trains given at baseline in both MwA and MwoA patients as compared with the healthy subjects (P < .00001).The main result of the study was that cathodal tDCS, which reduces the cortical excitability level, but not anodal tDCS, which increases it, restored the normal facilitatory response to the hf-rTMS trains in both MwA and MwoA. CONCLUSIONS: The present findings strengthen the notion that, in migraine with and without aura, the threshold for inducing inhibitory mechanisms of cortical excitability might be lower in the interictal period. This could represent a protective mechanism counteracting cortical hyperresponsivity. Our results could be helpful to explain some conflicting neurophysiological findings in migraine and to get insight into the mechanisms underlying recurrence of the migraine attacks.

Transcranial direct current stimulation preconditioning modulates the effect of high-frequency repetitive transcranial magnetic stimulation in the human motor cortex.

Experimental studies emphasize the importance of homeostatic plasticity as a mean of stabilizing the properties of neural circuits. In the present work we combined two techniques able to produce short-term (5-Hz repetitive transcranial magnetic stimulation, rTMS) and long-term (transcranial direct current stimulation, tDCS) effects on corticospinal excitability to evaluate whether and how the effects of 5-Hz rTMS can be tuned by tDCS preconditioning. Twelve healthy subjects participated in the study. Brief trains of 5-Hz rTMS were applied to the primary motor cortex at an intensity of 120% of the resting motor threshold, with recording of the electromyograph traces evoked by each stimulus of the train from the contralateral abductor pollicis brevis muscle. This interventional protocol was preconditioned by 15 min of anodal or cathodal tDCS delivered at 1.5 mA intensity. Our results showed that motor-evoked potentials (MEPs) increased significantly in size during trains of 5-Hz rTMS in the absence of tDCS preconditioning. After facilitatory preconditioning with anodal tDCS, 5-Hz rTMS failed to produce progressive MEP facilitation. Conversely, when 5-Hz rTMS was preceded by inhibitory cathodal tDCS, MEP facilitation was not abolished. These findings may give insight into the mechanisms of homeostatic plasticity in the human cerebral cortex, suggesting also more suitable applications of tDCS in a clinical setting.

Sleep quality in caregivers of patients with Alzheimer's disease and Parkinson's disease and its relationship to quality of life.

BACKGROUND: Knowledge about sleep complaints of caregivers of patients with Alzheimer's disease (AD) and Parkinson's disease (PD) is limited, and we lack information about the relationship between caregivers' sleep problems and their quality of life (QoL). METHODS: We evaluated subjective sleep quality and its relationship to QoL in a group of 80 caregivers of patients with AD (ADCG, n = 40) and PD (PDCG, n = 40), and in 150 controls. Information about night-time complaints was collected using the Pittsburgh Sleep Quality Index (PSQI). QoL was measured using the McGill QoL Questionnaire. RESULTS: Eighteen ADCG (45%), 22 PDCG (55%), and 45 (30%) controls reported poor sleep quality. Mean global PSQI score of PDCG (6.25 ± 3.9) was not significantly different from that of ADCG (5.8 ± 3.5; p = 0.67). However, both PDCG and ADCG scored significantly higher than control group (4.3 ± 3.1; p < 0.01). ADCG frequently reported difficulties falling asleep (72.5%) and disturbed sleep (100%). PDCG reported reduced subjective sleep quality (80%) and increased sleep disturbances (100%). Poor sleep quality was associated with depressive symptoms and correlated with QoL in caregivers of both groups, particularly the psychological symptoms domain. CONCLUSIONS: Among caregivers of patients with AD and PD, poor sleep quality is frequent and significantly linked to QoL and depressive symptoms. Identifying the nature of sleep disturbances not only in patients but also in their caregivers is important as appropriate treatment may lead to a better management of the needs of families coping with these patients.

Impaired glutamatergic neurotransmission in migraine with aura? Evidence by an input-output curves transcranial magnetic stimulation study.

OBJECTIVE: An imbalance between activity of inhibitory and facilitatory intracortical circuits could play a central role in migraine etiology. We used input-output curves to achieve further information about intracortical excitability of motor cortex in migraine with aura. METHODS: Input-output curves were measured in the right abductor pollicis brevis muscle at rest in 12 patients suffering from migraine with aura and 8 healthy subjects. Stimuli were delivered at intensity ranging from 100% to 160% of resting motor threshold with 10-second inter-stimulus intervals. Seven patients were studied before and during treatment with levetiracetam. RESULTS: Results showed a greater motor-evoked potential amplitude in response to increasing intensity of stimuli in patients compared to controls (P < .02). This increased facilitatory effect was abolished by levetiracetam (P < .005). CONCLUSIONS: Our findings support the hypothesis of an interictal cortical hyper-responsivity in migraine patients that appears to be normalized by levetiracetam. This effect could support the potential therapeutic role of levetiracetam in migraine with aura prevention.

Reversible posterior leukoencephalopathy syndrome in a patient with thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is an autoimmune disorder characterised by fever, microangiopathic haemolytic anaemia, renal insufficiency, and thrombocytopenia. Neurological involvement, a prominent component of TTP, is characterised by a variety of brain lesions which include reversible cerebral oedema or magnetic resonance imaging (MRI) features of reversible posterior leukoencephalopathy syndrome (RPLS). TTP is frequently associated with deficiency of the von Willebrand factor-cleaving protease, ADAMTS13.Here, we report a case of TTP with severe acute encephalopathy. Posterior leukoencephalopathy and brainstem oedema with triventricular hydrocephalus were observed on MRI. The low activity of ADAMTS13 was not observed and ADAMTS-13 antibodies were absent. Neurological symptoms and patient's condition were completely resolved by plasma exchange therapy in addition to high dose of methylprednisolone.

Different forms of trigeminal autonomic cephalalgias in the same patient: description of a case.

The trigeminal autonomic cephalalgias (TACs), including cluster headache, paroxysmal hemicrania and SUNCT, are characterized by the cardinal combination of short-lasting unilateral pain and autonomic phenomena affecting the head. Hemicrania continua (HC) shares many clinical characteristics with TACs, including unilateral pain and ipsilateral autonomic features. Nevertheless, HC is separately classified in the revised International Classification of Headache Disorders (ICHD-II). Here, we describe the case of a 45-year-old man presenting an unusual concurrence of different forms of primary headaches associated with autonomic signs, including subsequently ipsilateral cluster headache, SUNCT and HC. This report supports the theory that common mechanisms could be involved in pathophysiology of different primary headache syndromes.

Cyclical changes of cortical excitability and metaplasticity in migraine: evidence from a repetitive transcranial magnetic stimulation study.

The primary brain dysfunctions leading to the onset of a migraine attack remain largely unknown. Other important open questions concern the mechanisms of initiation, continuation, and termination of migraine pain, and the changes in brain function underlying migraine transformation. Brief trains of high-frequency repetitive transcranial magnetic stimulation (rTMS), when applied to the primary motor cortex at suprathreshold intensity (⩾120% of resting motor threshold [RMT]), elicit in healthy subjects a progressive, glutamate-dependent facilitation of the motor evoked potentials (MEP). Conversely, in conditions of increased cortical excitability, the rTMS trains induce inhibitory MEP responses likely mediated by cortical homeostatic mechanisms. We enrolled 66 migraine-without-aura patients, 48 migraine-with-aura patients, 14 patients affected by chronic migraine (CM), and 20 healthy controls. We assessed motor cortical response to 5-Hz rTMS trains of 10 stimuli given at 120% RMT. Patients with episodic migraine were studied in different phases of the migraine cycle: interictal, preictal, ictal, and postictal states. Results showed a facilitatory MEP response during the trains in patients evaluated in the preictal phase, whereas inhibitory responses were observed during and after a migraine attack, as well as in CM patients. In the interictal phase, different responses were observed, depending on attack frequency: facilitation in patients with low and inhibition in those with high attack recurrence. Our findings suggest that changes in cortical excitability and fluctuations in the threshold for inhibitory metaplasticity underlie the migraine attack recurrence, and could be involved in the process of migraine transformation.

MRI abnormalities following repeated and incoming seizures.

Neuroimaging, an important diagnostic tool frequently used in the evaluation of patients with epilepsy, has mainly the aim to identify structural abnormalities needing a treatment and to contribute to the definition of the aetiology. Brain magnetic resonance imaging (MRI) in epilepsy is more sensitive than computerized tomography (CT) scan for detecting abnormalities. Status epilepticus (SE) and repeated incoming seizures may determine extensive and transient or long lasting pronounced MRI changes. We describe a case of a 41-year-old woman with a history of brain neoplasm, whose contrast-enhanced MRI images following repeated and incoming seizures were characterized either by reversible and irreversible abnormalities.

Abnormal facilitatory mechanisms in motor cortex of migraine with aura.

Experimental evidence suggests impairment of inhibitory intracortical circuits in migraine, while not much is known about activity of facilitatory intracortical circuits. In the present work we evaluated the effects of high frequency-repetitive transcranial magnetic stimulation (hf-rTMS) on the activity of facilitatory circuits of motor cortex in 18 patients affected by migraine with aura and 18 healthy subjects. Trains of 10 stimuli were applied to the motor cortex at 5-Hz frequency with recording of the EMG traces from the contralateral abductor pollicis brevis muscle (APB). Two intensities of stimulation (110% and 130% of resting motor threshold) were used in order to explore whether motor cortex excitability was differently modulated. Twelve patients underwent hf-rTMS both before and during prophylactic treatment with levetiracetam. Results showed that rTMS delivered at 110% intensity of stimulation at rest had a facilitatory effect on MEP size in untreated patients, while left MEP unchanged in controls. Conversely, when rTMS was applied at 130%, we observed MEP potentiation in healthy subjects and paradoxical MEP inhibition in migraineurs. In treated patients, levetiracetam inhibited MEP size at both 110% and 130% intensity of stimulation. Our findings reveal an opposite response of migraine motor cortex to 5-Hz rTMS when it is delivered at different stimulation intensities, providing evidence of both hyper-responsivity and self-limiting hyperexcitability capacity, in line with studies supporting the concept that under conditions of cortical hyperexcitability inhibitory mechanisms of homeostatic plasticity could be activated.