Homeostatic modulation of stimulation-dependent plasticity in human motor cortex.

Since recently, it is possible, using noninvasive cortical stimulation, such as the protocol of paired associative stimulation (PAS), to induce the plastic changes in the motor cortex, in humans that mimic Hebb's model of learning. Application of TMS conjugated with peripheral electrical stimulation at strictly coherent temporal manner lead to convergence of inputs in the sensory-motor cortex, with the consequent synaptic potentiation or weakening, if applied repetitively. However, when optimal interstimulus interval (ISI) for induction of LTP-like effects is applied as a single pair, Motor evoked potential (MEP) amplitude inhibition is observed, the paradigm known as short-latency afferent inhibition (SLAI). Aiming to resolve this paradox, PAS protocols were applied, with 200 repetitions of TMS pulses paired with median nerve electrical stimulation, at ISI equal to individual latencies of evoked response of somatosensory cortex (N(20)) (PAS(LTP)), and at ISI of N(20) shortened for 5 msec (PAS(LTD)) - protocols that mimic LTP-like changes in the human motor cortex. MEP amplitudes before, during and after interventions were measured as an indicator based on output signals originating from the motor system. Post-intervention MEP amplitudes following the TMS protocols of PAS(LTP) and PAS(LTD) were facilitated and depressed, respectively, contrary to MEP amplitudes during intervention. During PAS(LTP) MEP amplitudes were significantly decreased in case of PAS(LTP), while in the case of PAS(LTD) an upward trend was observed. In conclusions, a possible explanation for the seemingly paradoxical effect of PAS can be found in the mechanism of homeostatic modulation of plasticity. Those findings indicate the existence of complex relationships in the development of plasticity induced by stimulation, depending on the level of the previous motor cortex excitability.

The quality of life of patients after a lumbar microdiscectomy: a four-year monitoring study.

INTRODUCTION/AIM: Health-conditioned quality of patients' life is equally a result of their subjective perception of the disease and their objective condition. The aim of this paper is to evaluate the quality of life of surgically treated lumbar radiculopathy patients by using a generic and a lumbar disease-specific questionnaire. METHODOLOGY: 50 patients were evaluated (average age: 44.9 years; 52 male and 48 female). Two questionnaires were used for this purpose: the SF36 generic questionnaire, measuring eight quality of life domains divided into two sub-domains (overall physical and overall mental health), and the NASS LBP lumbar disease-specific questionnaire measuring four domains (pain and disability, motor and sensory neurogenic symptoms, expectations from the treatment and satisfaction with it). The results of the physical domain (SF36-PHYS) are low at the beginning of monitoring (25.7); they increase over the following 6 months (46.4) and drop insignificantly after 4 years (45.9). The mental health value (40.4) remained unchanged as compared to that of the general population. Values of the physical functioning domain reach that of the general population (80.0) after 6 months. Neurogenic symptoms domain results (NASS LBP-NS) do not correlate with other scales and domains. The conclusion is that the quality of life of patients after a lumbar microdiscectomy deteriorates significantly from a physical point of view immediately after it. It normalizes over the following 6 months, though a certain degree of physical damage still remains. Mental health alteration is not specific for lumbar radiculopathy. The neurogenic symptoms domain is the least improved dimension of their quality of life: it is very specific and to be evaluated with a special test set.

[Dysphagia rehabilitation].

Dysphagia and aspiration are important problems among the elderly population, particularly in neurological patients and patients with cancers of the oropharingeal area or laryngs. Early detection and rehabilitation are crucial because adequate management can reduce morbidity and complications like aspiration pneumonia, dehidratation and malnutrition. We overviewed rehabilitation procedures including nutritional management, postures, maneuvers, exercises and stimulation techniques and their efficacy in treatment of patients with dysphagias.

[Forensic importance of face, mouth, teeth, ear, throat, nose and labyrinth injuries].

Evaluation of bodily injuries and diminished general vital activity from face and facial bones injuries accompanied by scars and disfiguration ranges from 5 to 50 percent depending on the disfiguration, loss of function and degree of aesthetic marring. They are graded accordingly and they may be: mild (5 to 20%), medium (20 to 35%) and serious when the degree of bodily injury and diminished general vital activity is 35 to 50%. Percentage of bodily injuries and diminished general vital activity from jaw defects ranges from 30 to 80 percent depending on the disfiguration, loss of function and degree of aesthetic marring. Percentage of bodily injuries and diminished general vital activity from nose structure nasal pyramid defects ranges from 10 to 20 percent depending on the disfiguration, loss of function and degree of aesthetic marring. Partial loss of nose structure is estimated at 15%, whereas the complete one may go up to 30%. Diminished general vital activity and percentage of bodily injury with partial laryngectomy ranges from 20 to 40%. In case of subtotal laryngectomy, this is up to 60% and with total one, it reaches 80%.