N.M. Maurits

Fetal endoscopic myelomeningocele closure preserves segmental neurological function

Aim  Our aim was to compare the effect of prenatal endoscopic with postnatal myelomeningocele closure (fetally operated spina bifida aperta [fSBA]) versus neonatally operated spina bifida aperta [nSBA]) on segmental neurological leg condition.

Multichannel recording of median nerve somatosensory evoked potentials

OBJECTIVES Clinical applications of multichannel (>or=64 electrodes) electroencephalography (EEG) have been limited so far. Amplitude variability of evoked potentials in healthy subjects is large, which limits their diagnostic applicability. This amplitude variability may be partially due to spatial undersampling of anatomical variations in cortical generators. In the present study, we therefore investigated whether 128-channel recordings of somatosensory evoked potentials (SEPs) can reduce this amplitude variability in healthy subjects. Additionally, we explored the relation between amplitude and age. METHODS We recorded median nerve SEPs using a 128-channel EEG system in 50 healthy subjects (20-70 years) and compared N20, P27, and P45 amplitude as obtained with a 128-channel analysis method - based on butterfly plots and spatial topographies - and as obtained using a conventional one-cortical-channel configuration and analysis. Scalp and earlobe references were compared. RESULTS Although amplitude variability itself was not reduced, a reduced coefficient of variation was obtained with the 128-channel method due to higher SEP amplitudes, compared to the conventional one-channel method, independent of reference. CONCLUSION These results suggest that at the cost of some additional preparation time, the 128-channel method can measure SEP amplitude more accurately and might therefore be more sensitive to physiological and pathological changes. For optimal amplitude estimation, we recommend to increase the number of centroparietal electrodes or, preferably, to perform at least a 64-channel recording.

Reproducibility and variability of dynamic cerebral autoregulation during passive cyclic leg raising

Dynamic cerebral autoregulation (dCA) estimates require mean arterial blood pressure (MABP) fluctuations of sufficient amplitude. Current methods to induce fluctuations are not easily implemented or require patient cooperation. In search of an alternative method, we evaluated if MABP fluctuations could be increased by passive cyclic leg raising (LR) and tested if reproducibility and variability of dCA parameters could be improved. Middle cerebral artery cerebral blood flow velocity (CBFV), MABP and end tidal CO2 (PetCO2) were obtained at rest and during LR at 0.1 Hz in 16 healthy subjects. The MABP-CBFV phase difference and gain were determined at 0.1 Hz and in the low frequency (LF) range (0.06-0.14 Hz). In addition the autoregulation index (ARI) was calculated. The LR maneuver increased the power of MABP fluctuations at 0.1 Hz and across the LF range. Despite a clear correlation between both phase and gain reproducibility and MABP variability in the rest condition, only the reproducibility of gain increased significantly with the maneuver. During the maneuver patients were breathing faster and more irregularly, accompanied by increased PetCO2 fluctuations and increased coherence between PetCO2 and CBFV. Multiple regression analysis showed that these concomitant changes were negatively correlated with the MABP-CBFV phase difference at 0.1 Hz Variability was not reduced by LR for any of the dCA parameters. The clinical utility of cyclic passive leg raising is limited because of the concomitant changes in PetCO2. This limits reproducibility of the most important dCA parameters. Future research on reproducibility and variability of dCA parameters should incorporate PetCO2 variability or find methods to keep PetCO2 levels constant.

Standardized handwriting provides quantitative measures to assess bradykinesia, tremor and micrographia in Parkinson's disease

Objective: The socio-demographic, epidemiologic, clinical features and genetic causes of Parkinson’s disease patients attending the Neurology out-patients clinic of the Korle Bu Teaching and Comboni hospitals are reviewed. Background: Parkinson’s disease (PD) is a chronic and progressive neurodegenerative disease thought to be rare in Africa. A colloborative project with the Parkinson’s Institute in Milan, Italy is ongoing in Ghana. Methods: Consecutive patients clinically diagnosed with Parkinson’s disease over the last year who were enrolled in the ‘‘Parkinson’s disease in Africa collaboration project’’ were recruited. A detailed personal, family and social history was taken followed by a neurological examination, complete Unified Parkinson’s Disease Rating Scale (UPDRS) assessment (part I to part IV), Hoehn and Yahr staging and initiation of treatment with Levodopa. Patients are reviewed at 3, 6 and 12 months. Brain imaging with a head CT scan is done were feasible. A saliva sample was collected after informed consent for analysis of the LRRK2-G2019S mutation amongst others. Results: 35 subjects with parkinsonism have been identified so far: Mean age at onset 65.7610.5 years; disease duration 7.4563.1 years; Hoehn and Yahr stage 2. Mean daily levodopa dosage 5201187mg. The LRRK2 exon 41 screening did not reveal the presence of any G2019S mutation in the Parkinson’s disease patients studied so far. Recruitment of more patients, follow up at 6 months and 12 months as well as completion of UPDRS data are the main thrust of the study now Conclusions: A good response to Levedopa is seen and further genetic analysis is required

P937: Essential tremor and the olivocerebellar system – an fMRI study

there is an appreciable overlap between tremor-dominant PD and advanced ET with regard to basic tremor parameters like amplitude, frequency, activation pattern or phase deviation of different affected muscles. Methods: Postural hand tremor was measured using an ultrasound-based three-dimensional (3D) real time motion analysis system (CMS 70P, Zebris, Isny, Germany). Different spatiotemporal parameters of tremor like 3D amplitude, frequency and vector angles of hand tremor movement in the transversal plane through the metacarpal joints as well as the variation and dispersion of these parameters throughout two recorded sequences of 60s each were calculated. Statistical analysis used Student’s T-Test for unpaired samples. Results: A total of n=45 Patients (mean age ± SD 67±11 years) with considerable postural tremor (score ≥2 on UPDRS III item 21), diagnosed according to usual clinical criteria either with ET (n=22) or PD (only tremor type I; n=23), were included in the study. Mean tremor frequency was slightly but not significantly higher in the ET group (5.7±0.8Hz vs. 5.3±0.7Hz; p=0.084). However, both the variation of the 3D tremor amplitude over time (see Fig. 1A for examples in a single ET and PD patient) as well as the dispersion of the vector angle of the tremor beats in the metacarpal plane (Fig. 1B) were significantly higher in the PD group (p>0.05). In 20 out of 23 PD patients characteristic oscillations of the tremor amplitude could be observed (see Fig. 1A, tremor beats 150-300 in the PD example), but only in 6 out of 22 patients with ET. Conclusions: The analysis of particular spatiotemporal 3D parameters of tremor like the variation of tremor amplitude over time or the dispersion of the 3D vector angle of the tremor movement might be an additional diagnostic tool for the differentiation of patients with tremor-dominant PD from advanced ET.

P930: Reproducibility and validation of standardized handwriting tasks

Results: In power spectrum analysis, the most profound desynchronization of EEG was observed in alpha and beta bands over SA modulation. In the alpha band, the significant, relative power changes were seen on the nearly all the recording electrodes. The phase coherence of alpha band was most clearly directly related to changes in SA. The functional connectivity was lower as the participants felt themselves to adjust their own movements better. The electrodes (FP1, FP2, F7, F8, F3, FZ) in the anterior frontal lobe were functionally connected to the middle central, parietal, temporal, and occipital lobes in the right hemisphere during SA modulation. Conclusions: Alpha oscillation connecting the fronto-central area to several other brain regions appears most directly related to the sense of SA. Alpha oscillation may have a major functional role in SA processing. *Some of this data were presented at the MDS 16th International Congress of Parkinson’s Disease and Movement Disorders in 2012.

Initiation and inhibition of wrist movements in parkinson patients and healthy controls

This paper discusses Initiation and inhibition of wrist movements in parkinson patients and healthy controls. It was presented at the Fourteenth International Congress of Parkinsons Disease and Movement Disorders.

Patients with Parkinson's disease have a less differentiated muscle activation pattern than healthy controls during manual circle movement

This paper discusses Initiation and inhibition of wrist movements in parkinson patients and healthy controls. It was presented at the Fourteenth International Congress of Parkinsons Disease and Movement Disorders.

P25-17 Muscle ultrasound in pre-birth and early life: an application in spina bifida aperta

partial seizures when they brushed their teeth by themselves. We saw a severely disabled girl who developed tooth-brushing-induced seizures when her mother brushed her teeth. The aim of our study was to clarify the epileptogenic features of the tooth-brushing-induced seizures in our case. Patient: We diagnosed an 11-year-old girl who had severe mental retardation, hypotonic cerebral palsy, and epilepsy with tooth-brushing epilepsy. As she could not brush her teeth by herself due to the disabilities, her mother brushed her teeth daily. She had spontaneous simple partial seizures at the age of 1 year and 2 months, and developed the same type of seizures induced by tooth-brushing at the age of 8 years. The patient developed spontaneous simple partial seizures several times a day and the tooth-brusing-induced seizures consistently twice a day. Methods: We performed ictal EEG and [Tc-99m]HMPAO-SPECT at the time of the seizure induced by the tooth-brushing as well as interictal [F18]FDG and [C-11]FMZ-PET to identify the epileptogenic focus. Results: The ictal EEG showed rhythmic alpha waves for 2 seconds in the frontal regions bilaterally, followed by diffuse polyspikes. The ictal [Tc-99m]HMPAO-SPECT demonstrated hyperperfusion in the left parietal region, including the somatosensory cortex, where the interictal [F18]FDG and [C-11]FMZ showed low uptake of each radiotracer. Conclusions: Our results show that the epileptogenic focus during the tooth-brushing-induced seizures is located in the somatosensory cortex.

P5-9 Evidence from EMG and kinematics for detoriated muscle activation patterns during manual circle movement in patients with Parkinson's disease

normal control (CTL); any subject who had an mUPDRS rating scale of 1 was classified as MPS-mild; and any subject who had any an mUPDRS rating of 2 or higher was classified as MPS-severe. In order to measure physical activity in daily life, subjects wore an Actiwatch® on their non-dominant hand for one week, resulting in a measure of activity counts (AC). Results: Of the 714 participants with complete data, 114 subjects (16.0%) were classified as MPS-mild and 46 subjects (6.4%) as MPS-severe. Our measure of AC was 31.2±11.2 (mean ±SD, ×104) in the CTL group, 31.6±12.0 in the MPS-mild group, and 20.8±10.9 in the MPS-severe group. While there was no significant difference in AC between the CTL and MPSmild groups, AC was lower in the MPS-severe group compared with both the CTL and the MPS-mild groups. Diagnostic sensitivity of MPS-severe became 100% when we adopted a cutoff point of low physical activity, as measured by actigraphy, combined with the presence of subjective depression by GDS. Conclusion: Actigraphy may be a useful objective tool for screening MPS, especially MPS-severe.