Orofacial function and temporomandibular disorders in Parkinson's Disease: a case-controlled study.

BACKGROUND: The difficulties and challenges faced by people with Parkinson's disease (PD) in performing daily orofacial function are not systematically investigated. In this study, specific orofacial non-motor and motor symptoms and functions were systematically examined in PD patients in comparison to a matched control group. METHODS: The clinical case-controlled study was conducted from May 2021 to October 2022 and included persons with PD and age- and gender-matched persons without PD. The participants with PD were outpatients diagnosed with PD at the Department of Neurology at Bispebjerg University Hospital in Copenhagen, Denmark. The participants underwent a systematic clinical and relevant self-assessment of the orofacial function and temporomandibular disorders (TMD). The primary outcomes were objective and subjective assessments of the general orofacial function, mastication, swallowing, xerostomia and drooling. The secondary outcomes were the prevalence of TMD and orofacial pain. The difference in outcome measures between the two groups was analysed using chi-square and Mann-Whitney U test. RESULTS: The study included 20 persons with PD and 20 age- and gender-matched persons without PD. Both objectively and subjectively, persons with PD had poorer orofacial function than the control group. Persons with PD had also a significantly more severe limitation of jaw mobility and jaw function. The objective masticatory function was also significantly reduced for persons with PD compared to the control group, and 60% of persons with PD found it difficult to eat foods with certain consistencies while 0% of the control group reported that problem. Persons with PD could swallow less water per second and the average swallowing event was significantly longer for PD persons. Even though PD persons reported more xerostomia (58% for persons with PD and 20% for control persons), they also reported significantly more drooling than the control group. Additionally, orofacial pain was more prevalent in PD persons. CONCLUSIONS: Persons with PD have a compromised orofacial function. Furthermore, the study indicates a link between PD and orofacial pain. In order to screen and treat persons with PD accordingly, healthcare professionals should be aware of and address these limitations and symptoms. TRIAL REGISTRATION: The trial was approved by the Regional Committee on Research Health Ethics of the Capital Region (H-20,047,464), the Danish Data Protection Agency (514 - 0510/20-3000), and registered at ClinicalTrials.gov (NCT05356845).

Subdural to subgaleal EEG signal transmission: the role of distance, leakage and insulating affectors.

OBJECTIVE: To estimate the area of cortex affecting the extracranial EEG signal. METHODS: The coherence between intra- and extracranial EEG channels were evaluated on at least 10 min of spontaneous, awake data from seven patients admitted for epilepsy surgery work up. RESULTS: Cortical electrodes showed significant extracranial coherent signals in an area of approximately 150 cm(2) although the field of vision was probably only 31 cm(2) based on spatial averaging of intracranial channels taking into account the influence of the craniotomy and the silastic membrane of intracranial grids. Selecting the best cortical channels, it was possible to increase the coherence values compared to the single intracranial channel with highest coherence. The coherence seemed to increase linearly with an accumulation area up to 31 cm(2), where 50% of the maximal coherence was obtained accumulating from only 2 cm(2) (corresponding to one channel), and 75% when accumulating from 16 cm(2). CONCLUSION: The skull is an all frequency spatial averager but dominantly high frequency signal attenuator. SIGNIFICANCE: An empirical assessment of the actual area of cerebral sources generating the extracranial EEG provides better opportunities for clinical electroencephalographers to determine the location of origin of particular patterns in the EEG.

Channel selection for automatic seizure detection.

OBJECTIVE: To investigate the performance of epileptic seizure detection using only a few of the recorded EEG channels and the ability of software to select these channels compared with a neurophysiologist. METHODS: Fifty-nine seizures and 1419 h of interictal EEG are used for training and testing of an automatic channel selection method. The characteristics of the seizures are extracted by the use of a wavelet analysis and classified by a support vector machine. The best channel selection method is based upon maximum variance during the seizure. RESULTS: Using only three channels, a seizure detection sensitivity of 96% and a false detection rate of 0.14/h were obtained. This corresponds to the performance obtained when channels are selected through visual inspection by a clinical neurophysiologist, and constitutes a 4% improvement in sensitivity compared to seizure detection using channels recorded directly on the epileptic focus. CONCLUSIONS: Based on our dataset, automatic seizure detection can be done using only three EEG channels without loss of performance. These channels should be selected based on maximum variance and not, as often done, using the focal channels. SIGNIFICANCE: With this simple automatic channel selection method, we have shown a computational efficient way of making automatic seizure detection.

Concentration-dependent neurotoxicity of articaine: an electrophysiological and stereological study of the rat sciatic nerve.

BACKGROUND: We performed this study to quantify the detrimental effect of intraneural injection of 50 µL of saline, articaine 2%, or articaine 4% in the rat sciatic nerve. METHODS: Lumbar-evoked electrospinograms from stimulation of the sciatic nerve were recorded before and immediately after injection and again after 3 weeks. Test substance was injected into the right sciatic nerve, and the untreated left sciatic nerve served as control. The animals were killed after the 3-week follow-up, and cross-sections of the sciatic nerve were examined stereologically. RESULTS: The evoked spinal cord field potential in the articaine groups faded away immediately after injection and was concentration-dependently, significantly more reduced at the 3-week follow-up in comparison with the saline group. The response from the control sides was unaffected in all groups. The number of myelinated axons was unaffected by the treatment. The mean cross-sectional axon area and the mean myelin sheath thickness were significantly reduced in animals injected with articaine 4%. CONCLUSIONS: These observations indicate concentration-dependent neurotoxic injuries after injection of articaine with a significant difference between 2% and 4% formulations. The mechanical injury of needle penetration with saline injection had no significant effect on nerve conduction or histomorphology.

Functional aspects of treatment with implant-supported single crowns: a quality control study in subjects with tooth agenesis.

BACKGROUND: No comprehensive patient-centered and clinical evaluations of the functional effect of treatment with implant-supported single crowns (ISSC) have been reported previously. OBJECTIVE: To investigate whether and how treatment with ISSC affects masticatory function and Oral Health-Related Quality of Life (OHRQoL) in subjects with tooth agenesis. MATERIAL AND METHODS: In nine females and nine males (32 + or - 10 years) with agenesis treated with one to four ISSC (68% in the premolar region), the treatment effect and masticatory function were assessed. The evaluation was performed first after implant placement shortly before crown cementation, and again 1 month after cementation. It consisted of questionnaires [including Oral Health Impact Profile (OHIP-49)] and functional examination with plastic strips, the Dental Prescale Film and the Occluzer system, Xylitol color-changeable gum and slices of Granny Smith apple. RESULTS: The patients' satisfaction with treatment was high and they experienced a significant overall improvement in their OHRQoL (on average 13% reduction in the total OHIP scores). The cementation of the crowns was associated with a significant increase in the number of near occlusal tooth contacts, contact area, bite force, and masticatory ability and performance. Correspondingly, there was a significant, positive correlation between the number of tooth contacts and (1) occlusal contact area, (2) bite force, and (3) masticatory performance. CONCLUSION: Treatment with ISSCs in subjects with tooth agenesis significantly increased masticatory function subjectively and clinically as well as OHRQoL. However, as the functional parameters before replacement of the teeth corresponded to values in subjects with complete dentitions, the functional importance of the increase may be questioned.

Chewing in patients with severe neurological impairment.

OBJECTIVE AND DESIGN: As degenerative disease, infarction and hemorrhage in the CNS may compromise chewing, the aim was to classify and analyse such chewing disturbances. The case series included clinical and electromyographic recordings from 10 patients (ages 12-78 years) with neurological disorders. RESULTS: Classifications were involuntary munching (two women with dystonia which was abolished during mastication), ceased chewing function (three men with impaired volitional motor control and spasticity from locked-in syndrome, restricted chewing range (two men and one woman with reduced jaw opening due to paradoxical activity after brainstem lesions), and distorted chewing pattern (two men with dystonia resulting in blockings during chewing). CONCLUSION: The effect of the neurological impairment illustrated the complex control of mastication and the interaction between central and peripheral mechanisms, and the variation of the chewing disturbances was surprisingly great, even with similar diagnosis.

Quantitative immunohistochemistry of fluorescence labelled probes using low-cost software.

This paper describes simple procedures to process digital images in quantitative immunofluorescence microscopy. Monoclonal antibodies directed against the sarcoplasmic myosin heavy chain isoforms and against laminin, located on the basement membranes, were applied to sections of human skeletal muscle. The localisation and staining intensity of a fluorescent secondary antibody were recorded using an indirect histochemical method. The digitised images were pre-processed and the luminosities of appropriate structures were determined using existing tools in the widely used image processing software Photoshop from Adobe. Procedures to obtain a quantitative measure for the specific fluorescence signal (the background corrected fluorescence in the object) were developed. In addition, antibody binding to individual cells could be quantified whether these cells are well separated or not. The relation between the specific fluorescence signal and the dilution factor of the primary antibody could be measured to determine a suitable concentration of the antibody for incubation of the sections. The potential fading of the fluorescence signal with time and prolonged exposure to light from the microscope was explored and analysed. With the tools described in the present report it is thus possible also to optimize the topical immunohistochemical protocol in order to quantify the fluorescence signal.

Salivary cortisol level, salivary flow rate, and masticatory muscle activity in response to acute mental stress: a comparison between aged and young women.

BACKGROUND: Age-related effects on physiological stress reactions regarding changes in salivary cortisol concentration, saliva flow rate, and masticatory muscle activity, as well as the corresponding perceived mental stress and performance in response to acute stressors, have not yet been fully described. OBJECTIVE: Thus, the aim of this study was to assess the age-related variations in these variables in response to minor acute and naturalistic stressors in terms of computer tasks. METHODS: 13 aged (60-70 years old) and 13 young (20-30 years old) women with frequent practice and long experience with computer use were recruited by personal contact and flyers. The subjects were healthy and had full dental arches and no orofacial pain. The computer tasks were randomized and comprised a mentally demanding, modified Stroop colour-word test (CWT) and a less demanding reference test, both with a duration of 20 min and with equal physical demand. Visual analogue scales for global assessment of mental stress and perceived task difficulty and performance, measurements of saliva flow rate and cortisol concentration (unstimulated whole saliva), as well as surface electromyography of the temporalis and masseter muscles were used for assessment, and Spearman correlation analysis and Anova with repeated measures were used for statistical evaluation. RESULTS: The perceived task-related stress and task difficulty were significantly higher and the personal satisfaction with the task performance significantly poorer in the aged women. The cortisol concentration, indicating the stress level, showed a small, but significant increase in response to the tasks. Also the saliva flow rate increased. This response was most pronounced in the aged and during the CWT. The average electromyogram varied significantly between age groups and tasks, with higher levels and shorter relative periods with gaps in the aged women and in the CWT. In addition, the peak activity of the jaw elevator muscles at mouse clicking was significantly elevated as a form of co-activation or attention-related activity. CONCLUSIONS: The study showed marked differences in the response to mental demands in aged as compared with young women. The mental stress, reflected by increases of salivary cortisol concentration, saliva flow rate, visual analogue scale ratings, and activity level of the jaw elevator muscles, was more pronounced in the aged women in response to the computer tasks.