How proprioceptive impairments affect quiet standing in patients with multiple sclerosis

To assess if multiple sclerosis patients with proprioceptive impairment are specifically affected during quiet standing with eyes open and how they can develop motor compensatory processes, 56 patients, classified from sensory clinical tests as ataxo-spastic (MS-AS) or only having spasticity (MS-S), were compared to 23 healthy adults matched for age. The postural strategies were assessed from the centre-of-pressure trajectories (CP), measured from a force platform in the eyes open standing condition for a single trial lasting 51.2 s. The vertical projection of the centre of gravity (CGv) and its vertical difference from the CP (CP-CGv) were then estimated through a biomechanical relationship. These two movements permit the characterization of the postural performance and the horizontal acceleration communicated to the CG and from that, the global energy expenditure, respectively. Both MS-AS and MS-S groups demonstrate larger CGv and CP-CGv movements than healthy individuals of the same age. Whilst similar CGv values are noticed in both MS subgroups, suggesting similar postural performances, statistically significant differences are observed for the CP-CGv component. Biomechanically, this feature expresses the necessity for the MS-AS group to develop augmented neuro-muscular means to control their body movements, as compared to the MS-S group. By demonstrating for both groups of patients similar postural performance accompanied by a varying degree of energy expenditure to maintain undisturbed upright stance, this study reveals that MS-AS patients which are affected by proprioceptive loss can compensate for this deficit with more efficient control strategies, when standing still with their eyes open.     

Effects of bilateral vestibular nucleus lesions on cardiovascular regulation in conscious cats.

The vestibular system participates in cardiovascular regulation during postural changes. In prior studies (Holmes MJ, Cotter LA, Arendt HE, Cas SP, and Yates BJ. Brain Res 938: 62-72, 2002, and Jian BJ, Cotter LA, Emanuel BA, Cass SP, and Yates BJ. J Appl Physiol 86: 1552-1560, 1999), transection of the vestibular nerves resulted in instability in blood pressure during nose-up body tilts, particularly when no visual information reflecting body position in space was available. However, recovery of orthostatic tolerance occurred within 1 wk, presumably because the vestibular nuclei integrate a variety of sensory inputs reflecting body location. The present study tested the hypothesis that lesions of the vestibular nuclei result in persistent cardiovascular deficits during orthostatic challenges. Blood pressure and heart rate were monitored in five conscious cats during nose-up tilts of varying amplitude, both before and after chemical lesions of the vestibular nuclei. Before lesions, blood pressure remained relatively stable during tilts. In all animals, the blood pressure responses to nose-up tilts were altered by damage to the medial and inferior vestibular nuclei; these effects were noted both when animals were tested in the presence and absence of visual feedback. In four of the five animals, the lesions also resulted in augmented heart rate increases from baseline values during 60 degrees nose-up tilts. These effects persisted for longer than 1 wk, but they gradually resolved over time, except in the animal with the worst deficits. These observations suggest that recovery of compensatory cardiovascular responses after loss of vestibular inputs is accomplished at least in part through plastic changes in the vestibular nuclei and the enhancement of the ability of vestibular nucleus neurons to discriminate body position in space by employing nonlabyrinthine signals.     

Arm-plane representation of shoulder compensation during pointing movements in patients with stroke

Improvements in functional motor activities are often accompanied by motor compensations to overcome persistent motor impairment in the upper limb. Kinematic analysis is used to objectively quantify movement patterns including common motor compensations such as excessive trunk displacement during reaching. However, a common motor compensation to assist reaching, shoulder abduction, is not adequately characterized by current motion analysis approaches. We apply the arm-plane representation that accounts for the co-variation between movements of the whole arm, and investigate its ability to identify and quantify compensatory arm movements in stroke subjects when making forward arm reaches. This method has not been previously applied to the analysis of motion deficits. Sixteen adults with right post-stroke hemiparesis and eight healthy age-matched controls reached in three target directions (14 trials/target; sampling rate: 100 Hz). Arm-plane movement was validated against endpoint, joint, and trunk kinematics and compared between groups. In stroke subjects, arm-plane measures were correlated with arm impairment (Fugl-Meyer Assessment) and ability (Box and Blocks) scores and were more sensitive than clinical measures to detect mild motor impairment. Arm-plane motion analysis provides new information about motor compensations involving the co-variation of shoulder and elbow movements that may help to understand the underlying motor deficits in patients with stroke.     

The loss of dexterity in the bilateral lower extremities in patients with stroke

The aim of this study was to examine the dexterity of both lower extremities in patients with stroke. Twenty patients with stroke and 20 age-matched control subjects participated in this study. To determine the dexterity of the lower extremities, we examined the ability to control muscle force during submaximal contractions in the knee extensor muscles using a force tracking task. The root mean square errors were calculated from the difference between the target and response force. The root mean square error was significantly greater in the affected limb of patients with stroke compared with those of the unaffected limb and the control subjects, and in the unaffected limb compared with that of the control subjects. Furthermore, the root mean square error of the affected limb was related significantly to motor function as determined by Fugl-Myer assessment. These results demonstrate impairment of the dexterity of both the affected and the unaffected lower extremities in patients with stroke.     

Laboratory and sonographic findings in dialyzed patients with bilateral chronic knee pain versus dialyzed asymptomatic patients

The aim of this study is to evaluate connection of plasma level of beta2-microglobulin, C-reactive protein and uric acid as well as sonographic parameters like thickness of synovial membrane, thickness of femoral condylar cartilage and presence of joint effusion and Baker's cysts with bilateral knee pain in dialyzed patients, comparing them with parameters in asymptomatic dialyzed patients. Plasma levels of beta2-microglobulin and C-reactive protein were significantly higher in symptomatic patients while uric acid level showed no difference among the groups. In symptomatic patients synovial membrane was thicker and in those patients there were more knee effusions and Baker's cysts. Thickness of femoral condylar cartilage showed no difference between groups. That suggests that inflammatory mechanisms developing from beta2-microglobulin accumulation could be important factor in bilateral knee pain in dialyzed patients even in shorter duration dialysis.     

Word production errors in children with developmental language impairments

This review focuses on the errors that children with developmental language impairments make on three types of word production tasks: lexical retrieval, the elicitation of derivationally complex forms and the repetition of non-sense forms. The studies discussed in this review come principally from children with specific language impairment, and from children who are English-speakers or deaf users of British sign language. It is argued that models of word production need to be able to account for the data presented here, and need to have explanatory power across both modalities (i.e. speech and sign).     

双侧慢性硬膜下血肿与单侧慢性硬膜下血肿的临床比较

目的:双侧慢性硬膜下血肿和单侧慢性硬膜下血肿患者的临床比较。方法:将33例双侧慢性硬膜下血肿和119例单侧慢性硬膜下血肿患者的临床表现、诱发因素、CT扫描、术后并发症和疗效进行回顾性对比分析。结果:单侧慢性硬膜下血肿组平均年龄67岁,双侧慢性硬膜下血肿组平均年龄71岁(P>0.05),两组患者均以男性多见(P>0.05)。与单侧慢性硬膜下血肿组相比,双侧慢性硬膜下血肿组头痛/呕吐更常见(P<0.05),使用抗凝/抗血小板药物患者较多(P<0.05),中线移位>5mm少于双侧慢性硬膜下血肿组(P<0.05)。两组患者合并的常见系统疾病、术后并发症和疗效无显著性差异(P>0.05)。结论:双侧慢性硬膜下血肿易发生于使用抗凝/抗血小板药物的老年患者,颅内压增高征更明显。两组大多数患者术后均恢复良好。     

Congenital isolated absence of the nasal columella: reconstruction with an internal nasal vestibular skin flap and bilateral labial mucosa flaps

Congenital aplasia of the nasal columella is a very rare anomaly. The deformity is characterized by the isolated absence of the columella from the nasal tip to the root of the philtrum, including the medial crura of the alar cartilages; surrounding structures such as the septum, nose, and upper lip are normal. To the best of our knowledge, only four such cases have been described to date. The embryopathogenesis for this uncommon disease is presently unknown. Our report describes a 14-year-old girl with congenital agenesis of the columella as an isolated anomaly. Her family history was positive for the presence of the same congenital deformity, which also affected her older brother; there was, however, no consanguinity between the parents. The columella defect was reconstructed with an internal nasal vestibular skin flap and bilateral upper labial mucosa flaps. There are many techniques available to repair columella defects, including free grafts from the ear, local flaps from the forehead, face, upper lip, and nose, distant flaps such as tube pedicle flaps, and free flaps from the ear. Each of these techniques has advantages and disadvantages. Because of this, the treatment of columella defects should be individualized.