Visual cues combined with treadmill training to improve gait performance in Parkinson's disease: a pilot randomized controlled trial.

OBJECTIVE: To evaluate the effects of visual cues combined with treadmill training on gait performance in patients with Parkinson's disease and to compare the strategy with pure treadmill training. DESIGN: Pilot, exploratory, non-blinded, randomized controlled trial. SETTING: University Hospital of Munich, Germany. SUBJECTS: Twenty-three outpatients with Parkinson's disease (Hoehn and Yahr stage II-IV). INTERVENTIONS: Patients received 12 training sessions within five weeks of either visual cues combined with treadmill training (n = 12) or pure treadmill training (n = 11). MAIN MEASURES: Outcome measures were gait speed, stride length and cadence recorded on the treadmill. Functional tests included the Timed Up and Go Test, the Unified Parkinson's Disease Rating Scale and the Freezing of gait-questionnaire. Assessments were conducted at baseline, after the training period and at two months follow-up. RESULTS: After the training period (n = 20), gait speed and stride length had increased in both groups (p ⩽ 0.05). Patients receiving the combined training scored better in the Timed Up and Go Test compared with the patients receiving pure treadmill training (p ⩽ 0.05). At two months follow-up (n = 13), patients who underwent the combined training sustained better results in gait speed and stride length (p ⩽ 0.05) and sustained the improvement in the Timed Up and Go Test (p ⩽ 0.05). CONCLUSIONS: This pilot study suggests that visual cues combined with treadmill training have more beneficial effects on gait than pure treadmill training in patients with a moderate stage of Parkinson's disease. A large-scale study with longer follow-up is required.

Dynamics of postural control in Parkinson patients with and without symptoms of freezing of gait.

BACKGROUND: It has been suggested that dynamical measures such as sample entropy may be more appropriate than conventional measures when analyzing time series data such as postural sway. We evaluated conventional and dynamical measures of postural sway in Parkinson disease (PD) patients with and without freezing episodes. METHODS: COP (center of pressure) data were recorded during quiet standing with eyes open, eyes closed and while performing a dual task. Data for 16 patients with freezing of gait, 17 patients with no history of freezing and 24 healthy subjects were analyzed. The amount of postural sway was quantified using conventional measures, whereas for the characterization of the temporal structure of the COP data the normalized sway path and sample entropy was calculated. RESULTS: Mean radius was higher and sample entropy was lower in patients with freezing symptoms as compared to healthy subjects in all three conditions. Dual-tasking significantly increased sway path length in patients with freezing, while normalized sway path did not change over conditions in this group. CONCLUSIONS: Our findings show that postural sway is characterized by a combination of large radius, short normalized sway path and high regularity of the COP only in patients with freezing. This pattern becomes most prominent in a dual-task paradigm. This may explain higher occurrence of gait freezing in dual task situations with subsequent higher risk of falls. Results suggested that dynamic measures may add valuable information for characterizing postural stability in PD patients.

Dynamic visual cueing in combination with treadmill training for gait rehabilitation in Parkinson disease.

Various cueing techniques as well as treadmill training have been shown to be effective in the gait rehabilitation of patients with Parkinson disease. We present a novel setup combining both dynamic visual cueing and body weight-supported treadmill training. A nonambulatory patient with Parkinson disease received six training sessions. Continuous improvement of gait parameters was observed throughout the course of training. When comparing cued and noncued conditions in individual training sessions, it was found that step length was larger and that gait symmetry was enhanced in the cued condition. At the end of the training period, the patient was capable of walking short distances with a walking frame. In conclusion, dynamic visual cueing in combination with body weight-supported treadmill training seems to be a promising treatment strategy for patients with Parkinson disease, even in the case of severe impairment.

Pattern of local field potential activity in the globus pallidus internum of dystonic patients during walking on a treadmill.

The basal ganglia (BG) are involved in gait. This notion is exemplified by observations that gait is disturbed by most diseases that affect the BG. However, it is unclear in what way the BG are activated during gait. One method to investigate the activity of the BG is to record local field potentials (LFPs) from electrodes placed in the BG for therapeutic purposes. Nowadays, the globus pallidus internum (GPi) represents the target for deep brain stimulation (DBS) in dystonia. LFPs recorded from this area have been shown to delineate activity associated with dystonic cramps but also activity that may be relevant for certain types of movement. In this study we recorded LFPs from DBS electrodes implanted into the GPi of eight patients with dystonia during walking on a treadmill machine and compared these data with data acquired during rest (sitting and standing). There was no difference in the power of frequency bands during the sitting and standing conditions. LFP power in the theta (4-8 Hz), alpha (8-12 Hz) and gamma (60-90 Hz) frequency bands was higher during walking than during the resting conditions. Beta (15-25 Hz) frequencies were the only frequencies that were down-regulated during walking. The amplitude of the theta and alpha frequency bands was modulated during the gait cycle. These data shed light on the function of the BG in patients with dystonia and demonstrate that, during gait, their overall activity increases in a specific way without showing increases of narrow frequency bands.

Health-related quality of life and cognitive functioning in adult patients with supratentorial WHO grade II glioma: status prior to therapy.

The present prospective study intends to evaluate health-related quality of life (HRQL) and cognitive functioning in adult patients with supratentorial World Health Organization (WHO) grade II glioma (LGG) prior to observation/therapy and to determine possible influences of tumor-related factors on these measures. Adult patients with biopsy-proven supratentorial LGG were considered eligible (study period 18 months). Besides detailed documentation of patient clinical status we evaluated HRQL using the Short Form-36 (SF-36) Health Survey and applied the Beck Depression Inventory. Furthermore, attention and verbal memory functions were tested. Data from matched healthy control populations served as reference, and T-values were compared using Mann-Whitney U tests. For correlation of scores the Pearson test was utilized. Thirty-three patients with median Karnofsky Performance Status (KPS) of 80 were evaluated. Selective and divided attention showed significant impairment (P < 0.005), while verbal memory functions were unaffected. HRQL evaluated by SF-36 Health Survey was significantly reduced predominantly in the psychological domains (P < 0.025 to P < 0.0005). Nine patients displayed mild to moderate depression. Duration of symptoms >20 weeks and presence of seizures negatively affected aspects of HRQL, while cognitive functions were not influenced. KPS <80 correlated significant only with reduced physical functioning (P < 0.002) and role functioning (P < 0.01) on the SF-36 Health Survey. While displaying good clinical status, patients with LGG showed significant impairment in aspects of attention and affections of HRQL already at time of diagnosis. These results suggest that these impairments originate from the tumor and/or potentially from confrontation with the diagnosis itself.

The influence of essential oils on human vigilance.

Olfactory stimuli are used in aromatherapy to enhance mood, well-being and work efficiency. Nevertheless, the impact of fragrances on cognitive performance in humans is not well understood. The present investigation aimed to evaluate the effects of 1,8-cineol, jasmine absolute ether, linalyl acetate and peppermint essential oil on human vigilance performance. The odorants were administered by means of inhalation and, except for peppermint essential oil, were tested at 2 different dosages. Performance in a standard visual vigilance task was measured in terms of speed and accuracy and subjective ratings of the odorants were assessed in terms of pleasantness, intensity, arousal and stress. We hypothesized that 1,8-cineol, jasmine absolute ether and peppermint essential oil would improve vigilance performance, whereas linalyl acetate would impair such performance. Comparison of the performances of the seven independent experimental groups with that of a control group did not show any of the expected effects. In contrast, inhalation of linalyl acetate decreased reaction times. Within-group analyses, however, revealed significant interactions between subjective ratings of the odorants and task performance. The results of the present investigation emphasize the high impact of subjective factors on the modulation of attentional functions by olfactory stimuli in humans.

Sensitivity and reliability of language laterality assessment with a free reversed association task--a fMRI study.

OBJECTIVE: The aim of the study was to evaluate the sensitivity and reliability of assessing hemispheric language dominance with functional magnetic resonance imaging (fMRI) using a 'free reversed association task.' METHODS: Thirty-nine healthy subjects (13 dextrals, 13 sinistrals and 13 bimanuals) underwent two repeated fMRI sessions. In the active phases sets of words were presented via headphones, and an associated target item was named. During the baseline phases a standard answer was given after listening to unintelligible stimuli. Data were preprocessed with SPM, and then laterality indices (LI) and reliability coefficients (RC) were calculated. RESULTS: Extensive frontal, temporal and parietal activations were found. Seventy-eight percent of the subjects showed left-hemispheric dominance, 5% showed right-hemispheric dominance, and 17% had bilateral language representations. The incidence of right-hemispheric language dominance was 4.3 times higher in a left-hander with a handedness quotient (HQ) of -90 than in a right-hander with a HQ of +90. The RC was 0.61 for combined ROIs (global network). Strong correlations were found between the two session LIs (r = 0.95 for the global network). CONCLUSION: 'Free reversed association' is a sensitive and reliable task for the determination of individual language lateralization. This suggests that the task may be used in a clinical setting.

Intraoperative mapping of language functions: a longitudinal neurolinguistic analysis.

OBJECT: This prospective longitudinally designed study was conducted to evaluate language functions pre- and postoperatively in patients who underwent microsurgical treatment of tumors in close proximity to or within language areas and to detect those patients at risk for a postoperative aphasic disturbance. METHODS: Between 1991 and 2005, 153 awake craniotomies with subsequent cortical mapping of language functions were performed in 149 patients. Language functions were assessed using a standardized test battery. Risk factors were obtained from multivariate logistic regression models. RESULTS: Language mapping was able to be performed in all patients, and complete tumor resection was achieved in 48.4%. Within 21 days after surgery a new language deficit (aphasic disturbance) was observed in 41 (32%) of the 128 cases without preoperative deficits. There were a total of 60 cases involving postoperative aphasic disturbances, including cases both with and without preoperative disturbances. Risk factors for postoperative aphasic disturbance were preoperative aphasia (p<0.0002), intraoperative complications (p<0.02), language-positive sites within the tumor (p<0.001), and nonfrontal lesion location (p<0.001). In patients without a preoperative deficit, a normal (yet submaximal) naming performance was a powerful predictor for an early postoperative aphasic disturbance (p<0.0003). Seven months after treatment 10.9% of the 128 cases without preoperative aphasic disturbances continued to demonstrate new postoperative language disturbances. A total of 17.6% of all cases demonstrated new postoperative language disturbances after 7 months. Risk factors for persistent aphasic disturbance were increased age (>40 years, p<0.02) and preoperative aphasia (p<0.001). CONCLUSIONS: Every attempt should be undertaken to preserve language-relevant areas intraoperatively, even when they are located within the tumor. New postoperative deficits resolve in the majority of patients, which may be a result of cortical mapping as well as functional reorganization.

Reproducibility of activation in four motor paradigms. An fMRI study.

Most functional imaging data are collected in single session experiments; little is known about the reproducibility or test-retest reliability of the activation patterns found in these experiments. In our study, 15 healthy volunteers performed four simple motor-paradigms ("Hand", "Foot", "Mouth" and "Tongue") for functional magnetic resonance imaging (fMRI) in 3 sessions on different days. Reproducibility of activations in four anatomical regions (pre- and postcentral gyri, paracentral lobule and the supplementary motor area) was measured in terms of voxels active in all sessions (common voxels) relative to voxels active in single sessions, giving reliability coefficients from 0 to 1. Two significance levels were used to identify active voxels. Reproducibility of activations was highest for foot and hand movements in the primary motorsensory areas; reliability coefficients were in the range of 0.62 to 0.78. Activations for mouth movements showed a very poor reproducibility. Application of the more stringent statistical threshold always led to a reduction of reproducible voxels. Reliability of fMRI data is not only a theoretical issue, but is of special practical importance in clinical settings such as integration of fMRI into neuronavigation for neurosurgical planning. Much care has to be taken if only single session data are available for interpretation.

Surgical resection of grade II astrocytomas in the superior frontal gyrus.

OBJECTIVE: Surgery in the superior frontal gyrus partially involving the supplementary motor area (SMA) may be followed by contralateral transient weakness and aphasia initially indistinguishable from damage to the primary motor cortex. However, recovery is different, and SMA deficits may resolve completely within days to weeks. No study has assessed the distinct postoperative deficits after tumor resection in the SMA on a homogeneous patient group. METHODS: Twenty-four patients with World Health Organization Grade II astrocytomas in the superior frontal gyrus consecutively treated by surgery were studied. Degree and duration of postoperative deficits were evaluated according to tumor location and boundaries via magnetic resonance imaging scans, intraoperative neuromonitoring results, and extent of tumor resection. RESULTS: Postoperatively, motor deficits were evident in 21 of 24 and speech deficits in 9 of 12 patients. Motor function quickly recovered in 11 and speech function in 3 patients. None of the 12 patients in whom the posterior tumor resection line was at a distance of more than 0.5 cm from the precentral sulcus experienced persistent motor deficits. Eight of these patients developed typical SMA syndrome with transient initiation difficulties. Seven of 12 patients in whom the tumor extended to the precentral sulcus still had motor deficits at the 12-month follow-up assessment. CONCLUSION: Surgery for Grade II gliomas in the superior frontal gyrus is more likely to result in permanent morbidity when the resection is performed at a distance of less than 0.5 cm from the precentral gyrus or positive stimulation points. Therefore, cortical mapping of motor and speech function, in critical cases under local anesthesia with the patient as his or her own monitor, is recommended; resection should be tailored to obtain good functional outcome and maintain quality of life.

Naming tools and animals: asymmetries observed during direct electrical cortical stimulation.

Semantically bounded disorders of verbal processing that result in selective dysnomias for items belonging to specific semantic categories have been well documented in lesion studies. Most commonly dissociations between the categories of living versus non-living things have been reported. Processing of living things such as animals seems to be impaired after bilateral lesions, whereas lesions resulting in impairment of processing of non-living things such as tools seem to be restricted to the left hemisphere. In this study, we tested the naming capabilities of epilepsy patients with subdural electrodes implanted for localization of the epileptogenic zone and preoperative mapping of cognitive functions. Tool and animal items were used, and the results show that during stimulation of the left hemisphere dysnomias for tool items were more pronounced than for animal items. This asymmetry is discussed within a model of more widely bilaterally distributed processing of living category members as compared to more restricted left-sided representation of non-living category members.