Repetitive transcranial magnetic stimulation for patients with functional paralysis: a randomized controlled study.

BACKGROUND AND PURPOSE: Repetitive transcranial magnetic stimulation (rTMS) has been proposed to treat functional neurological disorders. Here, the aim was to assess the efficacy of rTMS to treat functional paralysis in a controlled randomized trial. METHODS: Patients received two sessions of active or sham 0.25 Hz rTMS (60 stimuli each), with a 1-day interval, applied over the motor cortex contralateral to the paralysis. The primary outcome was the number of patients with an increase in motor score between baseline and after the second rTMS session, rated by two investigators blinded to the treatment allocation. Secondary outcomes were changes in global and fine motor scores between groups after rTMS, and the occurrence of adverse events. RESULTS: Sixty-two patients (46 female; mean [SD] age, 35.2 [13.9] years) were enrolled and randomized. Thirteen out of 32 (41%) and 11/30 (37%) patients had increased motor strength after active or sham rTMS, respectively (p = 0.80). Changes in both global and fine motor scores after rTMS relative to baseline were also not significantly different between treatment groups (median difference in the global motor score 0.62 [0.83] and 0.37 [0.61], and in the fine motor scores 0.12 [0.18] and 0.08 [0.11], in active and sham rTMS groups, respectively; p = 0.14). Six serious adverse events, consisting of three cephalalgia in the active group and two cephalalgia and one asthenia in the sham group, were observed. CONCLUSIONS: Two sessions of sham or active low frequency rTMS were effective to improve functional paralysis, suggesting a placebo effect of this non-invasive brain stimulation technique.

Kinematics or Kinetics: Optimum Measurement of the Vertical Variations of the Center of Mass during Gait Initiation.

BACKGROUND: During gait, the braking index represents postural control, and consequently, the risk of falls. Previous studies based their determination of the braking index during the first step on kinetic methods using force platforms, which are highly variable. This study aimed to investigate whether determining the braking index with a kinematic method, through 3D motion capture, provides more precise results. METHODS: Fifty participants (20 to 40 years) performed ten trials in natural and fast gait conditions. Their braking index was estimated from their first step simultaneously using a force platform and VICON motion capture system. The reliability of each braking index acquisition method was assessed by intraclass correlation coefficients, standard error measurements, and the minimal detectable change. RESULTS: Both kinetic and kinematic methods allowed good to excellent reliability and similar minimum detectable changes (10%). CONCLUSION: Estimating the braking index through a kinetic or a kinematic method was highly reliable.

Reduced gait and postural stability under challenging conditions in fallers with upper limb fracture.

BACKGROUND: While most fractures are caused by falls, not all falls result in fractures. Risk factors for falls are well established, but only weak associations have been demonstrated for risk factors for fractures. Conflicting results on the implication of bone mineral density (BMD) suggest that other risk factors should be studied, such as gait and balance disorders. AIMS: Gait and postural stability in challenging conditions were, therefore, compared between fallers with and without fracture. METHODS: We enrolled 80 adults aged 55 and older who fell in the previous year. We compared gait and posture after obstacle crossing between fallers with an upper-limb fracture (n = 38), and fallers without fracture (n = 42). Data on BMD, body mass index, handgrip strength, fear of falling, number of comorbidities, number of falls, global cognition, executive functioning and education level were collected. RESULTS: Compared to fallers without fracture, fallers with fracture had significant lower gait velocity (Likelihood-Ratio = 4.93; P = 0.03) and lower postural stability during stabilization after obstacle crossing (Likelihood-Ratio = 10.99; P < 0.001). In addition, fallers with fracture had lower handgrip strength (Likelihood-Ratio = 9.92; P = 0.002), lower education level (Likelihood-Ratio = 8.32; P = 0.004), poorer executive functions (Likelihood-Ratio = 5.81; P = 0.02, higher fear of falling (Likelihood-Ratio = 5.55; P = 0.02) and were more likely women (Likelihood-Ratio = 17.55; P < 0.001), compared to fallers without fracture. DISCUSSION: This study demonstrated that the main difference between fallers with upper-limb fracture and fallers without fracture is mobility in dynamic condition. Poor executive function and low muscular strength could also be involved. CONCLUSIONS: These factors should be taken into account when assessing risk factors for fracture and implementing preventive programs. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov. NCT02292316.

Does Bilateral Deep Brain Stimulation of the Subthalamic Nucleus Modify Ano-Rectal Motility in Parkinson's Disease? Results of a Randomized Cross-Over Study.

BACKGROUND: Ano-rectal motility impairment is often observed during Parkinson's disease (PD), generating symptoms as constipation and/or incontinence with impaired quality of life. Subthalamic nuclei (STN) deep brain stimulation (DBS) improves motor symptoms of PD, but its effects on anorectal motility are unknown. This study aimed to assess the effects of STN-DBS on the anorectal motility in PD patients, in a randomized cross-over study. METHODS: Sixteen PD patients with bilateral STN-DBS for at least 6 months were included. The anal resting pressure, duration and maximal amplitude of squeeze effort, recto-anal inhibitory reflex, maximal tolerable rectal volume, and anal pressure during defecation effort were measured and compared after STN-DBS was switched OFF and then ON for 2 hours, or vice-versa, in a randomized order. KEY RESULTS: STN-DBS increased maximal amplitude of anal squeezing pressure (OFF: 85.7 ± 14.5 vs ON: 108.4 ± 21.0 cmH2 O; P = 0.02), with no significant difference in the duration (P = 0.10). No other significant difference was found between stimulation conditions (OFF vs ON) for anal resting pressure (OFF: 72.5 ± 8.6 cmH2 O vs ON: 71.7 ± 9.0 cmH2 O; P = 0.24), recto-anal inhibitory reflex, maximal tolerable rectal volume (OFF: 231 ± 24 mL vs ON: 241 ± 26 mL; P = 0.68), or anal pressure during defecation effort with a similar rate of ano-rectal dyssynergia (7/16 and 8/16 with and without STN-DBS, respectively). No order effect (ON-OFF vs OFF-ON) was observed. CONCLUSION AND INFERENCES: STN-DBS increased anal squeezing pressure, but did not modify anorectal dyssynergia in PD patients, This study demonstrated the involvement of STN in the voluntary control of anorectal motility in PD patients.

Effects of repetitive transcranial magnetic stimulation of the right inferior parietal lobe on the body image perception in anorexia nervosa: A pilot randomized controlled study.

INTRODUCTION: Restrictive anorexia nervosa (AN) is associated with distorted perception of body shape, previously linked to hypoactivity and reduced excitability of the right inferior parietal lobe (rIPL). Here, we investigated the impact of high-frequency repetitive transcranial magnetic stimulation (HF rTMS) of the rIPL on body shape perception in patients with AN. METHODS: Seventeen patients with AN (median [Q1_Q3] age, 35 [27_39] years; disease duration, 12 [6_18] years) were randomly assigned to receive real or sham HF (10 Hz) rTMS of the rIPL over a period of 2 weeks, comprising 10 sessions. The primary outcome measure was the Body Shape Questionnaire (BSQ). Secondary outcomes included eating disorder symptoms, body mass index, mood, anxiety, and safety. Data collection were done at baseline, post-rTMS, and at 2 weeks and 3 months post-rTMS. RESULTS: Following both real and sham rTMS of the rIPL, no significant differences were observed in body shape perception or other parameters. Both real and sham rTMS interventions were deemed safe and well tolerated. Notably, serious adverse events were associated with the underlying eating and mood disorders, resulting in hospitalization for undernutrition (five patients) or suicidal attempts (two patients). CONCLUSION: This pilot study does not support the use of rTMS of the rIPL as an effective method for improving body shape perception in individuals with the restrictive form of AN. Further research is warranted to comprehensively explore both the clinical and neurophysiological effects of HF rTMS in this population.

Early identification of seizure freedom with medical treatment in patients with mesial temporal lobe epilepsy and hippocampal sclerosis.

BACKGROUND: Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is usually associated with a poor response to antiseizure medications. We focused on MTLE-HS patients who were seizure free on medication to: (1) determine the clinical factors associated with seizure freedom and (2) develop a machine-learning classifier to better earlier identify those patients. METHODS: We performed a retrospective, multicentric study comparing 64 medically treated seizure-free MTLE-HS patients with 200 surgically treated drug-resistant MTLE-HS patients. First, we collected medical history and seizure semiology data. Then, we developed a machine-learning classifier based on clinical data. RESULTS: Medically treated seizure-free MTLE-HS patients were seizure-free for at least 2 years, and for a median time of 7 years at last follow-up. Compared to drug-resistant MTLE-HS patients, they exhibited: an older age at epilepsy onset (22.5 vs 8.0 years, p < 0.001), a lesser rate of: febrile seizures (39.0% vs 57.5%, p = 0.035), focal aware seizures (previously referred to as aura)(56.7% vs 90.0%, p < 0.001), autonomic focal aware seizures in presence of focal aware seizure (17.6% vs 59.4%, p < 0.001), dystonic posturing of the limbs (9.8% vs 47.0%, p < 0.001), gestural (27.4% vs 94.0%, p < 0.001), oro-alimentary (32.3% vs 75.5%, p < 0.001) or verbal automatisms (12.9% vs 36.0%, p = 0.001). The classifier had a positive predictive value of 0.889, a sensitivity of 0.727, a specificity of 0.962, a negative predictive value of 0.893. CONCLUSIONS: Medically treated seizure-free MTLE-HS patients exhibit a distinct clinical profile. A classifier built with readily available clinical data can identify them accurately with excellent positive predictive value. This may help to individualize the management of MTLE-HS patients according to their expected pharmacosensitivity.

Optoelectronic Study of Gait Kinematics in Sagittal Spinopelvic Imbalance.

OBJECTIVE: Degenerative processes induce loss of lumbar lordosis and anterior sagittal imbalance (ASI). Optoelectronic study provides kinematic analysis of movement and can also detect ASI. The aim of the present study was to assess gait kinematic modifications induced by ASI. METHODS: Thirty-five healthy male volunteers were subjected to reversible ASI induced by wearing a kyphotic thermoformed thoracolumbar corset. The deformation was assessed by C7 tilt on EOS (EOS Imaging, Paris, France) full-spine views. Ten optoelectronic gait recordings were made with corset and 10 without. Gait kinematic parameters (stride length, walking speed, rhythm), gait balance parameters (center of mass braking index, stride width, double support time) and spinal sagittal balance parameters (C7T10S1, C7´S1' and spinal angles) were averaged. Adjusted analysis distinguished direct ASI impact from locomotor factors. RESULTS: The corset-induced ASI produced +15° change in C7 tilt (P < 0.0001), -7.4° in C7T10S1 (P < 0.0001), +66.2 mm in C7´S1' (P < 0.0001), and +13.1° in spinal angle (P < 0.0001). Radiographic and optoelectronic data correlated significantly. Stride length (P < 0.0001) and rhythm (P = 0.0003) were significantly reduced, contributing to a reduction in walking speed (P < 0.0001), and strongly influencing double support time (ß = -0.38; 95% confidence interval [CI]: -0.69; -0.06). Center of mass braking index was significantly reduced (P < 0.0001) and significantly influenced by ASI (ß = -0.51; 95% CI: -0.78; -0.28). Stride width was significantly increased by ASI (P < 0.0001), independently of rhythm and stride length. CONCLUSIONS: ASI induced by a kyphotic corset was detectable on the optoelectronic system, leading to significant changes in gait kinematics. Locomotor parameters were significantly reduced. Balance parameters were significantly and directly altered by ASI.

Static and dynamic stabilometric force platform study of spinopelvic anterior sagittal imbalance.

BACKGROUND DATA: Anterior sagittal imbalance (ASI) is a severity factor in spinal pathology. Stabilometric study of the dynamic position of the center of pressure (CoP) assesses orthostatic control. These analyses provide the energy expenditure used for this control. HYPOTHESIS: Stabilometric signs are associated with ASI indicate increased energy expenditure. PATIENTS AND METHODS: Healthy male volunteers were subjected to reversible ASI induced by wearing a kyphotic thermoformed thoracolumbar corset. The deformation was assessed by C7 tilt on EOS whole-spine views. Static and dynamic posturographic force platform study was performed under conditions of anteroposterior and mediolateral instability. Mean CoP position (Xmean, Ymean) was studied on statokinesigram, with scatter assessed as confidence ellipse (CE). Path length according to CE surface (LAS) indicated energy expenditure. The stabilogram quantified displacement over time as lengths (Lx, Ly) and amplitudes (Ax, Ay). RESULTS: The corset significantly increased C7 tilt (p<0.0001). This did not significantly change mean CoP positions (Xmean and Ymean), but LAS was significantly increased (p=0.003). Static tests showed changes in Ly (p=0.0008) and Ax (p=0.003), and dynamic tests showed changes in Ly (p<0.0001), Lx (p<0.0001), Ax (p<0.0001), Ay (p<0.05) and CE (p<0.004). DISCUSSION: Posturographic parameters were impacted by inducing ASI in healthy subjects. Significant differences were seen in stabilography, CE and LAS, were greater on dynamic testing, and correlated with radiologic sagittal balance. Force platforms can reveal increased energy expenditure in maintaining posture. LEVEL OF EVIDENCE: II; Single-center prospective study involving healthy volunteers.

Ankle dorsiflexors and plantarflexors neuromuscular electrical stimulation training impacts gait kinematics in older adults: A pilot study.

BACKGROUND: While ankle muscles, highly affected by aging, are highly implicated in the changes in gait kinematics and involved in the limitation of seniors' mobility, whether neuromuscular electrical stimulation (NMES) training of these muscles could impact gait kinematics in older adults has not been investigated yet. RESEARCH QUESTION: What are the effects of 12 weeks of ankle plantar and dorsiflexors NMES training on strength and gait kinematics in healthy older adults? METHODS: Fourteen older adults (73.6 ± 4.9 years) performed a three-time per week, three months long NMES training of both ankle plantar and dorsiflexors. Before and after training, neuromuscular parameters, gait kinematic parameters, and daily physical activity were measured. RESULTS: The participants significantly increased their lower limb muscle mass and their plantar and dorsiflexors isometric strength after training. They reduced the hip abduction/adduction and the pelvic anterior tilt range of motion and variability during gait. However, the participants became less active after the training. SIGNIFICANCE: NMES training of ankle muscles, by increasing ankle muscle mass and strength,modified gait kinematics. NMES training of ankle muscles is feasible and effective to lower the hip implication and increment foot progression angle during gait. Further study should determine if this could lower the risk of falling.

Psychogenic paralysis and recovery after motor cortex transcranial magnetic stimulation.

Psychogenic paralysis presents a real treatment challenge. Despite psychotherapy, physiotherapy, antidepressants, acupuncture, or hypnosis, the outcome is not always satisfactory with persistent symptoms after long-term follow-up. We conducted a retrospective study to assess clinical features and to propose an alternative treatment based on repetitive transcranial magnetic stimulation (rTMS). Seventy patients (44 F/26 M, mean age: 24.7 +/- 16.6 years) experienced paraparesis (57%), monoparesis (37%), tetraparesis (3%), or hemiparesis (3%). A precipitating event was observed in 42 patients, primarily as a psychosocial event or a physical injury. An average of 30 stimuli over the motor cortex contralateral to the corresponding paralysis was delivered at low frequency with a circular coil. The rTMS was effective in 89% of cases, with a significantly better outcome for acute rather than chronic symptoms. In conclusion, motor cortex rTMS seem to be very effective in patients with psychogenic paralysis and could be considered a useful therapeutic option.

Recurrent seizures in a young woman: when video-EEG diagnoses a cardiac cause: a case report.

BACKGROUND: While transient loss of consciousness is a frequent presenting symptom, differential diagnosis between syncope and epilepsy can be challenging. Misdiagnosis of epilepsy leads to important psychosocial consequences and eliminates the opportunity to treat patient's true condition. CASE SUMMARY: A 39-year-old woman presenting with recurrent seizures since her childhood was referred to neurological consultation. Electroencephalograms (EEGs) and magnetic resonance imaging previously performed were normal. A sleep-deprived video-EEG was performed and highlighted after 12 h of sleep deprivation a progressive dropping of the heart rate followed by a complete heart block without ventricular escape rhythm and asystole for about 30 s. Her EEG recording later showed diffuse slow waves traducing a global cerebral dysfunction and suffering. The diagnosis of vaso-vagal syncope with predominant cardioinhibitory response was made and a dual-chamber pacemaker with rate-drop response algorithm was implanted. After a 2 years of follow-up, the patient remained free of syncope. DISCUSSION: Patients presenting with loss of consciousness and convulsion are often diagnosed with epilepsy despite normal EEGs. In patients presenting with recurrent seizures with unclear diagnosis of epilepsy or in a situation of drug-resistant epilepsy, syncope diagnosis should always be considered and a risk stratification is necessary. The benefit of pacemaker implantation in patients with recurrent vaso-vagal syncope is still very controversial. Only patients presenting with spontaneous asystole should be considered for pacemaker implantation in case of recurrent vaso-vagal syncope.

Plantar Flexor Strength Training With Home-Based Neuromuscular Electrical Stimulation Improves Limits of Postural Stability in Older Adults.

BACKGROUND: The study aimed to determine whether improved muscle strength after 12 weeks of neuromuscular electrical stimulation (NMES) of plantar and dorsiflexors could result in better limits of stability in older adults. METHODS: Twenty-seven participants were divided into a control group and a neuromuscular home-based training group. The training group performed a 3-month long NMES training of both plantar and dorsiflexors. Ankle flexor strength and limits of stability were measured. A mediation analysis was conducted to determine whether the NMES effect on the limits of stability was mediated by increased strength. RESULTS: The NMES training increased plantar flexor strength (+47%; ß = 0.217, P = .02), and this increase predicted the anterior limits of stability improvement (+27%; ß = 0.527, P = .02). The effect of the NMES on the limits of stability was fully mediated by the plantar flexor strength increase (indirect effect: ß = 0.1146; 95% confidence interval, 0.020-0.240). CONCLUSION: It seems that NMES improves the limits of stability through its positive effect on muscle strength. NMES may be utilized in fall-prevention programs.

Microsubthalamotomy effect at day 3: screening for determinants.

A microsubthalamotomy (mSTN) effect has been frequently reported after implantation that improves Parkinson's motor disability. It is usually believed that mSTN effect reflects the post-traumatic tissue reaction within the STN. However, it has never, to our knowledge, been reported whether pre and intraoperative factors could predict this mSTN effect. Preoperative clinical characteristics, that is, age, disease duration, Mattis Dementia Rating Scale score, levodopa responsiveness, severity of motor fluctuations and dyskinesia, and intraoperative parameters, that is, the number of tracks, distance of typical STN neuronal activity recorded along all microelectrodes, and along the definitive electrodes, were assessed in 40 consecutive PD patients submitted for STN stimulation. Multiple stepwise regression analysis showed that only the number of tracks used for microelectrodes recordings was predictor of the contralateral mSTN effect (F (4,73) = 1.83, P = 0.02). This result suggests that the contralateral mSTN depends on the tissue changes along the entirety of surgical trajectories affecting both STN and its adjacent structures.

Gait and balance disorders in Parkinson's disease: impaired active braking of the fall of centre of gravity.

Gait and balance disorders are common in Parkinson's disease (PD), but its pathophysiology is still poorly understood. Step length, antero-posterior, and vertical velocities of the center of gravity (CG) during gait initiation were analyzed in 32 controls and 32 PD patients, with and without levodopa, using a force platform. Brain volumes and mesencephalic surface area were measured in PD patients. During the swing limb period, controls showed a fall in the CG, which was reversed before foot-contact indicating active braking of the CG fall. In PD patients, without levodopa, step length and velocity were significantly reduced and no braking occurred before foot-contact in 22 patients. With levodopa, step length and velocity increased in all patients and 7 patients improved their braking capacity. PD patients with normal braking (n = 17) had significantly lower gait and balance disorder scores and higher normalized-mesencephalic surface areas compared to patients with impaired braking (n = 15). The decreased step length and velocity, characteristic of PD, mainly result from degeneration of central dopaminergic systems. The markedly decreased braking capacity observed in half the PD patients contributes to their gait disorders and postural instability, perhaps as a result of nondopaminergic lesions, possibly at the mesencephalic level.

Posturo-locomotor markers of preclinical Parkinson's disease.

Parkinson's disease (PD) is known to have a long prodromal stage due to the degeneration of dopaminergic neurons of the substantia nigra pars compacta over the course of many years without clinical manifestations of PD. When the diagnosis is made, the neuropathological process is already well entrenched. Consequently, identifying individuals during this prodromal period could be very helpful for future trials of neuroprotective or disease-modifying therapies, which might slow or prevent the degeneration of dopaminergic neurons. Thus, efforts are needed to determine appropriate early markers of PD. Gait and balance disorders are frequent during the early stages of PD. This systematic review aims to determine if gait and balance disorders occur before the diagnosis of PD and if so, whether they could be used as markers of preclinical PD. Findings reveal that, at the presymptomatic stage of PD, impaired basal ganglia function leads to disorders in gait and balance. Both clinical and instrumental assessments allow early detection of these disorders, particularly when performed under challenging conditions (e.g. dual-task). Among all studied parameters, temporal gait variability and arm kinematics appear to be promising markers of preclinical PD.

Bimanual Gesture Imitation Links to Cognition and Olfaction.

OBJECTIVES: Given the need to detect subclinical changes in brain health that sometimes occur with aging in apparently healthy older adults, we assessed whether bimanual gesture imitation performance, simple to assess clinically, can detect age effects and alterations in cognition, olfaction, and movement. DESIGN: Cross-sectional study. SETTING: Baltimore Longitudinal Study of Aging. PARTICIPANTS: Men and women, aged 22 to 101 years, without cognitive impairment, dementia, stroke, Parkinson disease, resting tremor, abnormal muscle tone, or abnormal coordination (N = 507). MEASUREMENTS: Bimanual gesture imitation was measured using a test validated in older adults. We assessed (1) cognition, including verbal memory, executive function, attention, visuospatial ability, visuoperceptual speed, and language; (2) manual dexterity with the Purdue Pegboard Test; (3) olfaction, using the 16-item Sniffin' Sticks Identification Test; (4) upper extremity motor function, using a computer-based finger tapping test; and (5) lower extremity motor function, including 6-meter usual and rapid gait speeds, 400-meter walk time, Health ABC Physical Performance Battery, and total standing balance time. Cross-sectional associations between bimanual gesture imitation performance and each measure were examined using linear regression after adjustment for age, sex, race, education, and body mass index. Models with mobility measures also adjusted for height. RESULTS: Higher gesture imitation performance was associated with younger age. After adjustment, a worse score was associated with worse olfaction, executive function, and visuospatial ability. Gesture imitation score was not associated with other cognitive measures or motor function. CONCLUSION: In persons without clinically detectable neurological conditions, poor bimanual gesture imitation is associated with other indicators of brain health, including olfaction and selected cognitive function domains. Bimanual gesture imitation may be useful clinically to detect subtle brain changes in apparently healthy older adults. J Am Geriatr Soc 67:2581-2586, 2019.

Prediagnostic markers of idiopathic Parkinson's disease: Gait, visuospatial ability and executive function.

BACKGROUND: Idiopathic Parkinson's disease (IPD) has a long preclinical phase. RESEARCH QUESTION: This study assesses data on prediagnostic markers of IPD from a longitudinal, natural history study of aging. METHODS: Participants were selected from the database of the Baltimore Longitudinal Study of Aging, and included 10 prediagnosed IPD cases (eight men and two women) and 30 age and sex matched healthy controls. Patients with prediagnosed IPD had already had an assessment for IPD 2.6 ± 1.3 years (range 1.0-5.3 years) before the actual diagnosis, including: gait speed (six-meter corridor walk), spatio-temporal gait parameters using Vicon motion capture, balance, upper-limb motor skills, neuropsychological profile, and non-motor symptoms. RESULTS: Prediagnosed IPD cases compared to controls had slower gait speed (Δ=-0.13 m.s-1, p = 0.03) due to shorter step length (Δ=-5 cm, p = 0.004), worse visuospatial ability (card rotation test, Δ=-42, p = 0.0001) and worse executive function (category fluency test, Δ=-2.6, p = 0.04). SIGNIFICANCE: Our findings identify dimensions that merit further study as prediagnostic markers of Idiopathic Parkinson's disease to identify patients who might benefit from future neuroprotective therapy in order to delay, or prevent, clinical manifestations.

Discordance between measured postural instability and absence of clinical symptoms in Parkinson's disease patients in the early stages of the disease.

We compared postural performances in early stage Parkinson's disease (PD) patients and healthy subjects, and to determine if PD patients have infraclinical postural instability. Nine PD patients and 18 age- and sex-matched control subjects were recorded with open eyes (OE) and closed eyes (CE) using a force platform in static and dynamic conditions with a mobile platform allowing antero posterior and medio lateral oscillations. Oscillations of the mobile platform and balance strategy were quantified using both a force platform and the Vicon system. Under static conditions with both OE and CE, PD patients had a larger center foot pressure sway area than the control subjects (P = 0.007 and P = 0.04, respectively). Under dynamic conditions, the PD patients' sway area was greater than that of the control subjects in the CE antero posterior position (P = 0.04). Oscillations of the mobile platform were not different between the two groups. Lastly, all subjects used an ankle strategy, but PD patients had larger head oscillations than the control subjects. Early stage PD patients have an infraclinical postural instability which is compensated when it is more difficult to maintain good balance, suggesting that the neurological mechanisms of balance are partially still operating at this stage of the disease.

Microsubthalamotomy: an immediate predictor of long-term subthalamic stimulation efficacy in Parkinson disease.

A microsubthalamotomy (mSTN) effect is commonly described after implantation that improves Parkinson's motor disability and is considered to be an obvious sign of good placement of the definitive electrode within the subthalamic nucleus (STN). There has been no formal study, however, demonstrating whether this mSTN effect can predict the long-term efficacy of STN stimulation in Parkinson Disease. The mSTN effect was defined by the percentage improvement of unified parkinson's disease rating scale (UPDRS III) baseline score assessed the third day morning following STN implantation, after at least a 12 hour withdrawal of dopaminergic treatment and before the programmable pulse generator was switched on. It was assessed in 30 consecutive patients with PD submitted for STN stimulation. Multiple stepwise regression analysis showed that mSTN effect (P = 0.005) and global mean intensity of stimulation (P = 0.004) were accurate independent predictors of the 6-month postoperative UPDRS III motor score improvement in the off-drug/on-stimulation condition.