The effect of age on post-activation depression of the upper limb H-reflex.

PURPOSE: Post-activation depression (PaD) refers to the inhibition of the H-reflex induced by a preceding conditioning stimulus able to activate the afferents mediating the H-reflex itself. PaD can be investigated assessing the frequency-related depression of the H-reflex. This parameter, which is highly correlated to the severity of spasticity, has been used in the longitudinal assessment of spastic patients, in particular to assess the effect of drugs and rehabilitation over the years. However, in such longitudinal assessment, changes observed might be age related and not only disease related. The aim of this study was to investigate the possible age effects on PaD. METHODS: The frequency-related depression of the flexor carpi radialis (FCR) H-reflex was examined in two groups of young (20 subjects; 28 ± 3 years) and aged (18 subjects; 69 ± 6 years) healthy subjects. PaD was evaluated by comparing the H-reflex amplitudes obtained with a stimulation frequency of 0.1 Hz with those obtained using higher frequencies (0.33-0.5-1-2 Hz). RESULTS: The results showed that frequency-related depression of the FCR H-reflex is similar in young and elderly subjects at all frequencies, with the exception of 2 Hz. CONCLUSION: Our study shows that ageing does not affect the frequency-related depression of the FCR H-reflex at the frequencies of 1 Hz or lower, supporting the reliability of this method to assess PaD in the clinical practice, particularly for the longitudinal assessment of spasticity. A decrease of GABA-ergic presynaptic inhibition seems to be the more likely explanation for the age-related changes that we observed at the frequency of 2 Hz.

Intravenous thrombolysis for acute ischemic stroke associated to extracranial internal carotid artery occlusion: the ICARO-2 study.

BACKGROUND AND PURPOSES: In a case-control study in patients with acute ischemic stroke and extracranial internal carotid artery (eICA) occlusion, thrombolytic treatment was associated with increased mortality. The aim of this cohort study was to assess the efficacy and safety of thrombolysis in patients with eICA occlusion compared to those without eICA occlusion. METHODS: Consecutive patients treated with intravenous tissue-type plasminogen activator within 4.5 h from symptom onset included in the Safe Implementation of Thrombolysis in Stroke - International Stroke Thrombolysis Registry (SITS-ISTR) in 20 Italian centres were analyzed. Acute carotid occlusion was diagnosed using ultrasound examination, angio-CT scan or angio-MRI. Since the SITS-ISTR database did not plan to report the site of vessel occlusion, each participating center provided the code of the patient with eICA occlusion. Patients were divided into 2 groups, those with and those without eICA occlusion. Main outcome measures were: death, disability (modified Rankin Scale, mRS, 3-6) and any intracranial bleeding at 3 months. Multiple logistic regression analysis was performed to reveal predictors for main outcomes. The following variables of interest were included in the analysis: presence of eICA occlusion, age, gender, diabetes mellitus, hyperlipidemia, atrial fibrillation, congestive heart failure, previous stroke, current smoking, antiplatelet treatment at stroke onset, baseline NIHSS score, baseline blood glucose, cholesterol and blood pressure, history of hypertension and stroke onset to treatment time. RESULTS: A total of 1,761 patients without eICA occlusion and 137 with eICA occlusion were included in the study. At 3 months, 42 patients were lost to follow-up (3 with eICA occlusion). Death occurred in 30 (22.4%) patients with eICA occlusion and in 175 (10.2%) patients without (p < 0.0001). Death or disability at 3 months occurred in 91 of 134 patients with eICA occlusion (67.9%) compared with 654 of 1,722 patients without eICA occlusion (37.9%, p < 0.0001). No or minimal disability at 3 months (mRS 0-1) was reported in 25 (18.7%) patients with eICA occlusion and in 829 (48.2%) patients without (p < 0.0001). Any intracranial bleeding detected by CT or MRI at posttreatment imaging was seen in 16 (11.7%) patients with eICA occlusion and in 314 (17.8%) of those without (p = 0.09). The proportion of symptomatic intracerebral hemorrhage was 5.8% for patients with eICA occlusion and 8.0% for patients without (p = 0.16). At logistic regression analysis, eICA occlusion was associated with mortality (odds ratio, OR 5.7; 95% confidence interval, CI 2.9-11.1) and mortality or disability (OR 5.0; 95% CI 2.9-8.7) at 90 days. CONCLUSIONS: This cohort study in patients with acute ischemic stroke treated with thrombolysis showed an association between eICA occlusion and adverse outcome.

Recurring hyperammonemic encephalopathy induced by bacteria usually not producing urease.

BACKGROUND: Hyperammonemic encephalopathy may occur when urease-positive bacteria in the urinary tract produce ammonium which directly enters systemic circulation. Predisposing conditions such as a neurogenic bladder can increase both urinary tract infection and urine stagnation. CASE PRESENTATION: We describe the case of a 66 years old woman with a neurogenic bladder who twice developed hyperammonemic encephalopathy following urinary tract infection. During the second episode Escherichia coli and Enterococcus faecalis have been isolated in the urine. The neurologic examination showed psychomotor slowing, weak photomotor reflex, nystagmus in the lateral gaze and asterixis. The EEG showed triphasic waves which disappeared along with clinical recovery. CONCLUSION: Escherichia coli and Enterococcus faecalis are commonly considered urease-negative bacteria. Although frequently involved in urinary tract infections, their role in causing hyperammonemic encephalopathy have not been previously reported. Moreover, despite only one case with a neurogenic bladder have been described so far, our is the first patient with reoccurring hyperammonemic encephalopathy secondary to urinary tract infections.

Central nervous system involvement in mycosis fungoides: relevance of tcr gene testing in cerebrospinal fluid.

INTRODUCTION: Mycosis Fungoides (MF) is a rare malignant T-cell lymphoma, involving mainly the skin. In 50%-75% of cases, it can involve organs other than skin, with a 11%-14% Central Nervous System involvement (CNS). CASE REPORT: A 82-year-old woman presented to our Department with a 15-years history of MF with skin lesions. Neurological examination showed dysarthria and a left facio-brachial-crural hemiparesis. A CT scan showed a right fronto-rolandic lesion. A MRI, including DWI, confirmed the presence of the "neoplastic" lesion with slight hemorrhagic component and leptomeningeal contrast enhancement. Molecular TCR rearrangement test by PCR analysis was performed on skin biopsy, showed the presence of a single peak which fits with a monoclonal TCRG gene rearrangement (size 67). Molecular TCR test was also performed on the cerebrospinal fluid (CSF), which confirmed the presence of lymphocyte clone T g/ more expressed with the same size of that observed in the skin biopsy A total body CT scan did not show any lymphnodal or extranodal disease. The patient died after ten days. CONCLUSION: MF usually occurs in the context of advanced and often histologically transformed cutaneous disease. Isolated CNS involvement is remarkably rare. This case highlights the need for regular neurologic follow-up after the diagnosis of MF, in particular when features that suggest risk of disease progression are present. Furthermore, the analysis of the skin biopsy and above all of CSF by PCR technique, based on our experience, should always be executed in MF patients with signs or symptoms suggesting CNS involvement.

Manual linear movements to assess spasticity in a clinical setting.

In a clinical setting, where motor-driven systems are not readily available, the major difficulty in the assessment of the stretch reflex lies in the control of passive limb displacement velocity. A potential approach to this problem arises from the use of manual sinusoidal movements (made by continuous alternating flexions and extensions) paced by an external stimulus. Unfortunately, there are conditions in which sinusoidal movements induce interfering phenomena such as the shortening reaction or postactivation depression. In the present paper, a novel manual method to control the velocity of passive linear movements is described and the results obtained from both healthy subjects and spastic patients are reported. This method is based on the synchronisation of movements with tones played by a metronome at different speeds. In a first set of experiments performed in healthy subjects, we demonstrated consistent control of velocity during passive limb movements using this method. Four joints usually examined during muscle tone assessment were tested: wrist, elbow, knee and ankle joints. Following this, we conducted a longitudinal assessment of the stretch reflex amplitude in wrist flexor muscles in patients with spasticity treated with botulinum toxin type A. The evaluators were not only able to vary the movement velocity based on the metronome speed, but also could reproduce the respective speeds two weeks later, despite the changing degree of hypertonia. This method is easy to perform in a clinical setting and hardware requirements are minimal, making it an attractive and robust procedure for the widespread clinical assessment of reflex hypertonia.