Publications by authors named "Johannes H Koelman"

Objective: To study the effect of botulinum neurotoxin (BoNT) treatment in jerky and tremulous functional movement disorders (FMD).

Methods: Patients with invalidating, chronic (>1 year) symptoms were randomly assigned to two subsequent treatments with BoNT or placebo every 3 months with stratification according to symptom localisation. Improvement on the dichotomised Clinical Global Impression-Improvement scale (CGI-I) (improvement vs no change or worsening) at 4 months, assessed by investigators blinded to the allocated treatment was the primary outcome.

View Article and Find Full Text PDF

Objective: To evaluate the effectiveness of a specialized physical therapy (SPT) program on disability in cervical dystonia (CD) compared to regular physical therapy (RPT).

Design: A single-blinded randomized controlled trial.

Setting: This study was performed by a physical therapist in a primary health care setting.

View Article and Find Full Text PDF

Cervical dystonia (CD) is the most frequent form of focal dystonia. Symptoms often result in pain and functional disability. Local injections of botulinum neurotoxin are currently the treatment of choice for CD.

View Article and Find Full Text PDF

Background: Effective sensorimotor integration is essential to modulate (adapt) neck stabilization strategies in response to varying tasks and disturbances. This study evaluates the hypothesis that relative to healthy controls cervical dystonia patients have an impaired ability to modulate afferent feedback for neck stabilization with changes in the frequency content of mechanical perturbations.

Methods: We applied anterior-posterior displacement perturbations (110s) on the torso of seated subjects, while recording head-neck kinematics and muscular activity.

View Article and Find Full Text PDF

Objective: Functional or psychogenic movement disorders (FMD) present a diagnostic challenge. To diagnose FMD, clinicians must have experience with signs typical of FMD and distinguishing features from other hyperkinetic disorders. The aim of this study was to clarify the decision-making process of expert clinicians while diagnosing FMD, myoclonus, and tics.

View Article and Find Full Text PDF

Introduction: We describe the natural history of patients with a Zellweger spectrum disorder (ZSD) surviving into adulthood.

Methods: Retrospective cohort study in patients with a genetically confirmed ZSD.

Results: All patients (n = 19; aged 16-35 years) had a follow-up period of 1-24.

View Article and Find Full Text PDF

We aimed to determine profiles of information processing deficits in the pathway to first psychosis. Sixty-one subjects at ultrahigh risk (UHR) for psychosis were assessed, of whom 18 converted to a first episode of psychosis (FEP) within the follow-up period. Additionally, 47 FEP and 30 control subjects were included.

View Article and Find Full Text PDF

Objective: Propriospinal myoclonus (PSM) is a rare disorder with repetitive, usually flexor arrhythmic brief jerks of the trunk, hips, and knees in a fixed pattern. It has a presumed generation in the spinal cord and diagnosis depends on characteristic features at polymyography. Recently, a historical paradigm shift took place as PSM has been reported to be a functional (or psychogenic) movement disorder (FMD) in most patients.

View Article and Find Full Text PDF

Hypoxic ischemic encephalopathy after perinatal asphyxia is a major cause of mortality and morbidity in infants. Here, we evaluated pathologic changes in the hippocampi of a cohort of 16 deceased full-term asphyxiated infants who died from January 2000 to January 2009. Histochemical and immunocytochemical results for glial and neuronal cells were compared between cases with or without seizures and to adult and sudden infant death syndrome cases (n = 3 each).

View Article and Find Full Text PDF

Tonic dystonia of the limbs in complex regional pain syndrome (CRPS) is associated with considerable disability. Treatment options are scarce. Botulinum toxin (BoNT) is sometimes used, but the effect is often said to be disappointing.

View Article and Find Full Text PDF

Background: Prediction studies in subjects at Clinical High Risk (CHR) for psychosis are hampered by a high proportion of uncertain outcomes. We therefore investigated whether quantitative EEG (QEEG) parameters can contribute to an improved identification of CHR subjects with a later conversion to psychosis.

Methods: This investigation was a project within the European Prediction of Psychosis Study (EPOS), a prospective multicenter, naturalistic field study with an 18-month follow-up period.

View Article and Find Full Text PDF

Background: To describe the neurologic profiles of Rhizomelic chondrodysplasia punctata (RCDP); a peroxisomal disorder clinically characterized by skeletal abnormalities, congenital cataracts, severe growth and developmental impairments and immobility of joints. Defective plasmalogen biosynthesis is the main biochemical feature.

Methods: Observational study including review of clinical and biochemical abnormalities, genotype, presence of seizures and neurophysiological studies of a cohort of 16 patients with RCDP.

View Article and Find Full Text PDF

Background: The period preceding the first psychotic episode is regarded as a promising period for intervention. We aimed to develop an optimized prediction model of a first psychosis, considering different sources of information. The outcome of this model may be used for individualized risk estimation.

View Article and Find Full Text PDF

Background: To investigate the effect of mild hypothermia on conduction times and amplitudes of median nerve somatosensory evoked potentials (SEP) in patients after cardiopulmonary resuscitation (CPR).

Methods: Patients treated with hypothermia after CPR who underwent SEP recording during hypothermia and after rewarming were selected from a prospectively collected database. Latencies and amplitudes of N9 (peripheral conduction time, PCT), N13, and N20 were measured.

View Article and Find Full Text PDF

Cannabis use has consistently been associated with psychotic symptoms as well as cognitive impairments. Moreover, its use may provoke subclinical psychotic symptoms and is associated with neuropsychological dysfunctions in subjects at ultra high risk (UHR) for developing psychosis. However, to our knowledge, no data are yet available on the relationship between cannabis use, UHR symptoms and information processing as assessed with event related potentials (ERP) in UHR subjects.

View Article and Find Full Text PDF

Background: Over 60 Asian and European families with cortical myoclonic tremor and epilepsy have been reported under various names. Cerebellar changes may be part of the syndrome. In this study, we report the neuropathology findings in a new Dutch familial cortical myoclonic tremor with epilepsy case and review the literature on this syndrome.

View Article and Find Full Text PDF

Objective: To assess the diagnostic value of the bereitschaftspotential (BP) in jerky movement disorders.

Methods: A cross-sectional case series of 48 patients with psychogenic jerks, Gilles de la Tourette syndrome (GTS) or myoclonus was investigated. We measured the BP prior to the spontaneous jerk and voluntary wrist extension.

View Article and Find Full Text PDF

Background: Acute posthypoxic myoclonus (PHM) can occur in patients admitted after cardiopulmonary resuscitation (CPR) and is considered to have a poor prognosis. The origin can be cortical and/or subcortical and this might be an important determinant for treatment options and prognosis. The aim of the study was to investigate whether acute PHM originates from cortical or subcortical structures, using somatosensory evoked potential (SEP) and electroencephalogram (EEG).

View Article and Find Full Text PDF

Background: The focal primary torsion dystonias (FPTDs) form a group of clinical heterogeneous syndromes and can be considered a genetic complex disease; it is thought to be primed by genetic variants with variable impact and triggered by non-genetic factors. Thorough clinical description of FPTDs cohorts is sparse but essential for further progress in genetic research.

Objective: To establish suggested relations between age at onset (AaO), site and family history in a large focal dystonias cohort and gain more insight into familial clustering for genetic research.

View Article and Find Full Text PDF

Objective: This study was designed to establish the reliability of neurologic examination, neuron-specific enolase (NSE), and median nerve somatosensory-evoked potentials (SEPs) to predict poor outcome in patients treated with mild hypothermia after cardiopulmonary resuscitation (CPR).

Methods: This multicenter prospective cohort study included adult comatose patients admitted to the intensive care unit (ICU) after CPR and treated with hypothermia (32-34°C). False-positive rates (FPRs 1 - specificity) with their 95% confidence intervals (CIs) were calculated for pupillary light responses, corneal reflexes, and motor scores 72 hours after CPR; NSE levels at admission, 12 hours after reaching target temperature, and 36 hours and 48 hours after collapse; and SEPs during hypothermia and after rewarming.

View Article and Find Full Text PDF

Rett syndrome is characterized by loss of motor and social functions, development of stereotypic hand movements, seizures, and breathing disturbances. This study evaluates the presence of overnight respiratory disturbances. Polysomnography in combination with a questionnaire (the Sleep Disturbance Scale for Children) was performed in 12 Dutch patients with Rett.

View Article and Find Full Text PDF

The origin of the startle reflex lies in the caudal brainstem; it can be elicited by an unexpected stimulus resulting in a bilateral activation of many muscles. Two subsequent responses can be measured during EMG recordings; after the initial motor reflex, lasting until about 150 ms, a second response can occur. The second response contains more emotional and voluntary behavioral responses.

View Article and Find Full Text PDF