Publications by authors named "Pavel Hok"

Brain imaging studies in complex regional pain syndrome (CRPS) have found mixed evidence for functional and structural changes in CRPS. In this cross-sectional study, we evaluated two patient cohorts from different centers and examined functional connectivity (rsFC) in 51 CRPS patients and 50 matched controls. rsFC was compared in predefined ROI pairs, but also in non-hypothesis driven analyses.

View Article and Find Full Text PDF
Article Synopsis
  • Cognitive impairment (CI) in multiple sclerosis (MS) is linked to changes in brain connectivity measured by fMRI, but clear biomarkers for CI are needed.
  • A study compared a new index (k) based on graph theory with traditional imaging markers to assess its ability to differentiate between MS patients and healthy controls, focusing on cognitive processing speed.
  • Results showed lower k values in MS patients, indicating potential as a biomarker for CI and fatigue, but further validation is required due to moderate differentiation ability.
View Article and Find Full Text PDF

Background: The aim of this study was to examine the societal costs of polypharmacy in patients with multiple sclerosis (MS). We therefore focused on the association between the number of medications on the level of care (LOC), the German classification of the need for care, and the number of therapy sessions (TTU).

Methods: In addition to demographic information and medication, 101 MS patients performed the Multiple Sclerosis Health Resource Utilization Survey (MS-HRS).

View Article and Find Full Text PDF

Background: Integrity of the corticospinal tract (CST) is an important biomarker for upper limb motor function following stroke. However, when structurally compromised, other tracts may become relevant for compensation or recovery of function.

Methods: We used the ENIGMA Stroke Recovery data set, a multicenter, retrospective, and cross-sectional collection of patients with upper limb impairment during the chronic phase of stroke to test the relevance of tracts in individuals with less and more severe (laterality index of CST fractional anisotropy ≥0.

View Article and Find Full Text PDF

In post-stroke spasticity (PSS), effective treatment with botulinum neurotoxin (BoNT) is associated with transient decrease in activation of the ipsilesional superior parietal lobule (SPL) and intraparietal sulcus (IPS). We hypothesized that this would be reflected in changes in resting-state functional connectivity (rsFC) of the SPL/IPS. Our aim was therefore to assess rsFC of the ipsilesional SPL/IPS in chronic stroke patients with hemiparesis both with and without PSS and to explore the relationship between SPL/IPS rsFC and PSS severity.

View Article and Find Full Text PDF

Purpose: The aim of the study was to obtain the values of oxygen saturation in retinal vessels and ophthalmic blood flow parameters in a healthy Caucasian population and assess whether the oximetry parameters are affected by the flow rate or the vascular resistance.

Methods: The spectrophotometric retinal oximetry and colour Doppler imaging (CDI) of retinal vessels were successfully performed with 52 healthy subjects (average age 29.7 ± 5.

View Article and Find Full Text PDF

The "Different Hearing" program (DHP) is an educational activity aimed at stimulating musical creativity of children and adults by group composing in the classroom, alternative to the mainstream model of music education in Czechia. Composing in the classroom in the DHP context does not use traditional musical instruments or notation, instead, the participants use their bodies, sounds originating from common objects as well as environmental sounds as the "elements" for music composition by the participants' team, with the teacher initiating and then participating and coordinating the creative process, which ends with writing down a graphical score and then performing the composition in front of an audience. The DHP methodology works with a wide definition of musical composition.

View Article and Find Full Text PDF

In dystonic and spastic movement disorders, abnormalities of motor control and somatosensory processing as well as cortical modulations associated with clinical improvement after botulinum toxin A (BoNT-A) treatment have been reported, but electrophysiological evidence remains controversial. In the present observational study, we aimed to uncover central correlates of post-stroke spasticity (PSS) and BoNT-A-related changes in the sensorimotor cortex by investigating the cortical components of somatosensory evoked potentials (SEPs). Thirty-one chronic stroke patients with PSS of the upper limb were treated with BoNT-A application into the affected muscles and physiotherapy.

View Article and Find Full Text PDF

In cervical dystonia, functional MRI (fMRI) evidence indicates changes in several resting state networks, which revert in part following the botulinum neurotoxin A (BoNT) therapy. Recently, the involvement of the cerebellum in dystonia has gained attention. The aim of our study was to compare connectivity between cerebellar subdivisions and the rest of the brain before and after BoNT treatment.

View Article and Find Full Text PDF

Magnetic resonance imaging (MRI) is the gold standard imaging technique for diagnosis and monitoring of many neurological diseases. However, the application of conventional MRI in clinical routine is mainly limited to the visual detection of macroscopic tissue pathology since mixed tissue contrasts depending on hardware and protocol parameters hamper its application for the assessment of subtle or diffuse impairment of the structural tissue integrity. Multiparametric quantitative (q)MRI determines tissue parameters quantitatively, enabling the detection of microstructural processes related to tissue remodeling in aging and neurological diseases.

View Article and Find Full Text PDF

In dystonic and spastic movement disorders, however different in their pathophysiological mechanisms, a similar impairment of sensorimotor control with special emphasis on afferentation is assumed. Peripheral intervention on afferent inputs evokes plastic changes within the central sensorimotor system. Intramuscular application of botulinum toxin type A (BoNT-A) is a standard evidence-based treatment for both conditions.

View Article and Find Full Text PDF

Background: Stroke-like syndrome is defined as a rare, delayed complication of brain oncotherapy. Cases with more favorable brain cancer diagnoses and longer life expectancy have been previously reported, but here we present, for the first time, three long-term survivors of glioblastoma with stroke-like syndromes.

Methods And Results: Three young or middle-aged patients underwent tumor resection and chemoradiotherapy.

View Article and Find Full Text PDF

The complex phenomenological understanding of dystonia has transcended from the clinics to genetics, imaging and neurophysiology. One way in which electrophysiology will impact into the clinics are cases wherein a dystonic clinical presentation may not be typical or a "forme fruste" of the disorder. Indeed, the physiological imprints of dystonia are present regardless of its clinical manifestation.

View Article and Find Full Text PDF

Background: Typical lacunar syndromes do not include aphasia but aphasia has been reported in rare atypical lacunar syndromes.

Objective: Description of the phenomenology and of affected fiber tracts.

Material And Methods: Case series of three patients with lacunar stroke as evidenced by magnetic resonance imaging.

View Article and Find Full Text PDF

Peripheral afferent input is critical for human motor control and motor learning. Both skin and deep muscle mechanoreceptors can affect motor behaviour when stimulated. Whereas some modalities such as vibration have been employed for decades to alter cutaneous and proprioceptive input, both experimentally and therapeutically, the central effects of mechanical pressure stimulation have been studied less frequently.

View Article and Find Full Text PDF

Purpose: Optic neuritis (ON) is an inflammatory demyelinating disorder of the optic nerve, which can be the first manifestation of multiple sclerosis (MS). The main goal was to assess changes in the retinal nerve fibre layer (RNFL) and in retinal oxygen saturation [arterial (AS), venous (VS) and arterio-venous (A-V) difference] in the affected and unaffected eye.

Methods: Fifty patients with ON due to MS within 3 months of onset of symptoms were enrolled (17 males, mean age 35.

View Article and Find Full Text PDF

While in symptomatic forms of dystonia cerebral pathology is by definition present, it is unclear so far whether disease is associated with microstructural cerebral changes in idiopathic dystonia. Previous quantitative MRI (qMRI) studies assessing cerebral tissue composition in idiopathic dystonia revealed conflicting results. Using multimodal qMRI, the presented study aimed to investigate alterations in different cerebral microstructural compartments associated with idiopathic cervical dystonia .

View Article and Find Full Text PDF

Sustained pressure stimulation of the body surface has been used in several physiotherapeutic techniques, such as reflex locomotion therapy. Clinical observations of global motor responses and subsequent motor behavioral changes after stimulation in certain sites suggest modulation of central sensorimotor control, however, the neuroanatomical correlates remain undescribed. We hypothesized that different body sites would specifically influence the sensorimotor system during the stimulation.

View Article and Find Full Text PDF

The way the human brain represents speech in memory is still unknown. An obvious characteristic of speech is its evolvement over time. During speech processing, neural oscillations are modulated by the temporal properties of the acoustic speech signal, but also acquired knowledge on the temporal structure of language influences speech perception-related brain activity.

View Article and Find Full Text PDF

Post-stroke spasticity (PSS) is effectively treated with intramuscular botulinum toxin type A (BoNT-A), although the clinical improvement is likely mediated by changes at the central nervous system level. Using functional magnetic resonance imaging (fMRI) of the brain, this study aims to confirm and locate BoNT-A-related changes during motor imagery with the impaired hand in severe PSS. Temporary alterations in primary and secondary sensorimotor representation of the impaired upper limb were expected.

View Article and Find Full Text PDF

Botulinum toxin type A (BoNT) is considered an effective therapeutic option in cervical dystonia (CD). The pathophysiology of CD and other focal dystonias has not yet been fully explained. Results from neurophysiological and imaging studies suggest a significant involvement of the basal ganglia and thalamus, and functional abnormalities in premotor and primary sensorimotor cortical areas are considered a crucial factor in the development of focal dystonias.

View Article and Find Full Text PDF

Background: The physiotherapeutic technique of Vojta reflex locomotion is often accompanied by various autonomic activity changes and unpleasant sensations. It is unknown whether these effects are specific to Vojta Therapy. Therefore, the aim of this study was to compare changes in cardiac autonomic control after Vojta reflex locomotion stimulation and after an appropriate sham stimulation.

View Article and Find Full Text PDF

Objective: The purpose of this work was to optimize the acquisition of diffusion-weighted (DW) single-refocused spin-echo (srSE) data without intrinsic eddy-current compensation (ECC) for an improved performance of ECC postprocessing. The rationale is that srSE sequences without ECC may yield shorter echo times (TE) and thus higher signal-to-noise ratios (SNR) than srSE or twice-refocused spin-echo (trSE) schemes with intrinsic ECC.

Materials And Methods: The proposed method employs dummy scans with DW gradients to drive eddy currents into a steady state before data acquisition.

View Article and Find Full Text PDF

Background: Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction, potentially leading to severe disability. Abnormal cervical spine magnetic resonance imaging (MRI) and motor evoked potentials (MEPs) are independent predictors of disease progression. Abnormal MRI is accompanied by various activation changes in functional brain MRI (fMRI), whereas preoperative and postoperative fMRI adaptations associated with abnormal preoperative MEP remain unknown.

View Article and Find Full Text PDF

Aims: The relationship between freezing of gait (FOG) and regional brain atrophy has been intensively investigated, but it is still not clearly understood. The study objective was to test whether grey matter (GM) atrophy contributes to FOG in Parkinson's disease (PD) using a surface-based algorithm.

Methods: We investigated 21 patients with PD, 11 with FOG and 10 without FOG.

View Article and Find Full Text PDF