Shock waves modulate corticospinal excitability: A proof of concept for further rehabilitation purposes?

Background: Focal extracorporeal shock wave therapy (fESWT) is a physical therapy vastly studied and used for various musculoskeletal disorders. However, the effect of fESWT on central nervous system is still to be determined. Objective: To elucidate spinal and supra-spinal mechanisms of fESWT in healthy subjects, in order to widen the spectrum of its clinical applications. Methods: In this quasi-experimental, unblinded, proof-of-concept clinical study, 10 voluntary healthy subjects underwent fESWT and were assessed immediately before (T0), immediately after (T1) and seven days after (T2) the intervention. As neurophysiological outcomes, motor evoked potentials (resting motor threshold, maximal motor evoked potential and maximal compound muscle action potential ratio, cortical silent period, total conduction motor time, direct and indirect central motor conduction time), F-waves (minimal and mean latency, persistence and temporal dispersion) and H-reflex (threshold, amplitude, maximal H reflex and maximal compound muscle action potential ratio, latency) were considered. Results: Resting motor threshold and F-waves temporal dispersion significantly decreased, respectively, from T1 and T2 and from T0 and T2 (for both, p <  0.05). H-reflex threshold increase between T0 and T1. Analysis disclosed a strong negative correlation between Δ3 cortical silent period (i.e., T2 -T1 recordings) and Δ1 Hr threshold (i.e., T1 -T0 recordings) (r = -0.66, p <  0.05), and a positive strong relationship between Δ3 cortical silent period and Δ3 Hr threshold (r = 0.63, p <  0.05). Conclusions: fESWT modulates corticospinal tract excitability in healthy volunteers, possibly inducing an early inhibition followed by a later facilitation after one week.

Mild brain injury and anticoagulants: Less is enough.

BACKGROUND: Despite the higher theoretical risk of traumatic intracranial hemorrhage (ICH) in anticoagulated patients with mild head injury, the value of sequential head CT scans to identify bleeding remains controversial. This study evaluated the utility of 2 sequential CT scans at a 48-hour interval (CT1 and CT2) in patients with mild head trauma (Glasgow Coma Scale 13-15) taking oral anticoagulants. METHODS: We retrospectively evaluated the clinical records of all patients on chronic anticoagulation treatment admitted to the emergency department for mild head injury. RESULTS: A total of 344 patients were included, and 337 (97.9%) had a negative CT1. CT2 was performed on 284 of the 337 patients with a negative CT1 and was positive in 4 patients (1.4%), but none of the patients developed concomitant neurologic worsening or required neurosurgery. CONCLUSIONS: Systematic routine use of a second CT scan in mild head trauma in patients taking anticoagulants is expensive and clinically unnecessary.

Perceptual and response-related components of unilateral neglect may evolve independently of one another: evidence from five single-case studies.

The Milner Landmark Task allows the disentanglement of perceptual and response-related components of unilateral neglect. If these two components reflect separate functional systems, then cases should be observed in which the two components evolve differently across time. To test this hypothesis we surveyed a continuous series of 21 right hemisphere stroke patients. Five patients from the sample were affected by unilateral neglect at the outset and could be submitted to repeated administrations of the Landmark task in the first weeks post stroke. Two versions of the task were used, Landmark-Manual and Landmark-Verbal, differing in the type of response required. Two patients showed independent changes in the perceptual and the response-related component of neglect, hence confirming the view of separate functional systems underlying them. Dissociations between the task versions were found, witnessing a role of the type of response. Unexpectedly, one patient showed an initial leftward deviation of the subjective midpoint of the stimulus line, which later reversed to a classical rightward deviation. We interpreted such a pattern in terms of co-existing "productive" and "negative" components of perceptual neglect.

The assessment of colour perception, naming and knowledge: a new test device with a case study.

Besides ocular diseases, also cerebral damage may cause colour vision deficits; cerebral lesions may be associated with a variety of clinical conditions that impair colour processing. This study presents procedures and normative data for a rapid, comprehensive seven-test battery aimed at assessing colour perception, colour naming and object colour knowledge. The norms, obtained from 96 healthy Italian participants, allow normality/pathology judgements on the basis of one-sided tolerance limits, after adjusting the score of each test for the demographic variables of the proband subjects. We also report, as an example, use of the battery in a stroke patient; this patient was chosen because her lesion affected the left temporal-occipital cortex, an area sometimes associated with a deficit of colour processing. The patient resulted normal on colour perception and colour name retrieval, but defective on object colour knowledge probed using the stimulus name. For the sound definition of the functional locus of cognitive impairment at the single case level, a multi-faceted set of tasks is necessary.

Agranulocytosis and hepatic toxicity with ticlopidine therapy: a case report.

INTRODUCTION: Ticlopidine is a platelet inhibitor used to prevent thrombosis in patients with cerebrovascular or coronary artery disease. The most common side effects are mild and transitory: diarrhea, dyspepsia, nausea and rashes. More serious, but less frequent, adverse effects are hematological dyscrasia and cholestatic hepatitis. We report a rare case of agranulocytosis associated with hepatic toxicity, probably related to the use of ticlopidine. CASE PRESENTATION: A 70-year-old Caucasian woman, with no previous history of hematological or liver diseases, was treated with ticlopidine 250 mg twice daily immediately after a vertebrobasilar stroke. Upon admission, her blood tests were normal. About four weeks later she developed agranulocytosis and hepatic toxicity. Ticlopidine was discontinued immediately, and aspirin 25 mg and dipyridamole 200 mg were given twice daily. She was treated with hematopoietic growth factors (granulocyte colony stimulating factor), with a rapidly increased white blood count and progressive normalization of liver tests as a result. CONCLUSION: In the first three months following initiation of ticlopidine therapy, regular monitoring of complete blood cell count and of liver function tests is essential for the early detection of serious and unpredictable side effects.

Posterior cerebral artery infarcts and semantic category dissociations: a study of 28 patients.

In this study we analysed the relationship between damage in the territory of the posterior cerebral artery and semantic knowledge, with special reference to category dissociations. Twenty-eight posterior cerebral artery stroke patients (18 left, 8 right and 2 bilateral posterior cerebral artery infarctions) completed a neuropsychological battery aimed at assessing semantic knowledge. The battery included picture naming, word-picture matching, a verbal semantic questionnaire and a picture reality decision task. For each participant, the lesion was reconstructed on the basis of MRI images, and was classified according to the involvement of the areas supplied by posterior cerebral artery. Defective naming scores were observed in 12 of 18 left posterior cerebral artery cases (67%), four of eight right posterior cerebral artery cases (50%), and one of two bilateral posterior cerebral artery cases (50%). Only in the bilateral posterior cerebral artery lesion case did we observe the pattern expected in pure visual agnosia, i.e. poor picture naming, poor picture reality decision, and normal verbal semantic questionnaire. Nine left posterior cerebral artery cases and two right posterior cerebral artery cases presented with poor performance on both the picture naming task and the verbal semantic questionnaire, thus suggesting semantic impairment. For 5 of the 12 left posterior cerebral artery patients who fared poorly on the naming task, biological stimuli (overall) were significantly more impaired than artifacts. In three of these five subjects, performance on plant-life stimuli was significantly less accurate than that on animals. A further left posterior cerebral artery patient presented a disproportionate impairment on plant-life stimuli only on the word-picture matching and on the questionnaire. The patterns of performance in these subjects suggest that the observed dissociations originated at the semantic level. Among left posterior cerebral artery patients, a naming deficit only occurred when damage to the fusiform gyrus extended anterior to Talairach's y-coordinate -50, and a disproportionate impairment of biological categories only when the lesion extended anterior to y = -32.5. Results show that the semantic deficit for the category of plant life is a genuine cognitive pattern, and does not depend on loss of colour knowledge. The contrast of left posterior cerebral artery strokes and herpes simplex encephalitis cases shows that the neural substrates for the semantic representation of plant life and animals are, at least in part, distinct. Middle and posterior portions of the left fusiform are crucial for the representation of plant-life knowledge, whereas left anterior temporal areas are more crucial than left posterior and basal temporal areas for the representation of knowledge about animals.