PubMed Health⌕ Search

Biomedical subjects

J G van Dijk

Publications and source records attributed to J G van Dijk.

At least 19 recordsLinked to original sources
PubMed1998

['Inclusion body'-myositis].

In 3 patients, a 72-year-old man, a 62-year-old man and a 73-year-old woman with weakness of respectively the quadriceps femoris, the finger flexors and the pharyngeal muscles, the diagnosis of 'inclusion body myositis' was made. This is a rare, slowly progressive skeletal muscle disorder which is more common in men and after the age of fifty. The activity of serum creatine kinase is often 2-5 times the highest normal value. The electromyogram pattern is myopathic, but can also display neuropathic changes (exclusively). Inclusion body myositis is often misdiagnosed, which can lead to an inappropriate treatment or approach. A frozen muscle biopsy is needed to make cryostat sections for demonstration of myositis with rimmed vacuoles.

Aged↗
PubMed1998

The diagnostic value of the EEG in Angelman and Rett syndrome at a young age.

We determined the diagnostic value of the EEG in young children with Angelman syndrome (AS) and Rett syndrome (RS). EEGs, recorded before 5 years of age, of 10 patients with AS, 10 with RS and 10 with mental retardation of other origin were studied blindly by two examiners for the presence of the following items: (A) 4-6 Hz rhythmic activity of over 200 microV; (B) 2-3 Hz frontal activity of 200-500 microV; (C) posterior spikes; (D) triphasic frontal waves; (E) central and/or centro-temporal spike-wave complexes; and (F) other epileptic discharges. Based on these items the EEGs were scored as AS (A-D); RS (E-F); or other. Examiners never made a mistake between AS and RS. One examiner labeled 6 of 10 AS cases correctly, the other 5; 4 (5) were characterized as 'other.' In RS cases 5 were labeled as 'other' by the first examiner and 3 by the second one. We conclude that EEG patterns of AS and RS are sufficiently different to help differentiate between AS and RS at a young age, which has a bearing on genetic counseling.

Angelman Syndrome↗
PubMed1998

Cortical excitability of the biceps muscle after intercostal-to-musculocutaneous nerve transfer.

OBJECTIVE: Restoration of volitional control over elbow flexion has been demonstrated in patients who have undergone intercostal-to-musculocutaneous nerve transfer. We investigated the cortical area involved in the control over elbow flexion after intercostal-to-musculocutaneous nerve transfer. METHODS: Maps of magnetically excitable cortical areas of the affected arms of five patients were compared with maps of their healthy arms and maps of both arms of four healthy control subjects. The intercostal cortical area was also studied, requiring needle electromyography mapping (n = 1). RESULTS: The cortical areas of affected arms were smaller and less excitable than those of healthy arms. The locations of these areas could not be distinguished from that of the normal cortical biceps area but seemed to differ from that of the intercostal cortical area. CONCLUSION: The existence of a biceps-like cortical area related to the reinnervated muscle can be explained in two ways. Interneurons from the original biceps area might excite the cortical neurons controlling the intercostal muscles. Alternatively, corticospinal neurons of the original biceps area may project directly onto spinal intercostal motor neurons. Cerebral plasticity does occur in intercostal-to-musculocutaneous nerve transfers and may be crucial for their clinical success.

Adolescent↗
PubMed1998

Prolonged coma and severely attenuated EEG after a single seizure.

A 63-year-old woman presented with a comatose state after a fall. Results of cranial computed tomography (CT) and magnetic resonance imaging (MRI) scans were normal. An EEG recorded 5 h after admission was very severely attenuated and slowed. Consciousness and EEG were improved the next day. No cause was detected initially. After sleep deprivation, the patient had a generalized seizure followed by a similar coma and EEG. Even a single seizure may cause a prolonged coma with a very severely attenuated and slowed EEG.

Accidental Falls↗
PubMed1998

Changing central nervous system control following intercostal nerve transfer.

OBJECT: The goal of this study was to find which central nervous system (CNS) pathways are involved in volitional control over reinnervated biceps or pectoral muscles. METHODS: Intercostal nerves (ICNs) were coapted to the musculocutaneous nerve (MCN) or the medial pectoral nerve (MPN) in 23 patients with root avulsions of the brachial plexus to restore biceps or pectoral muscle function. The facilitatory effects of respiration and voluntary contraction on cortical motor-evoked potentials of biceps or pectoral muscles were used to study CNS control over the reinnervated muscles. The time course of the facilitatory effect of respiration and voluntary contraction differed significantly. In the end stage of nerve regeneration, the facilitatory effect of voluntary contraction was significantly larger than that of respiration, indicating that the CNS control network over the muscle comes to resemble that of the recipient nerve (MCN or MPN) rather than that of the donor nerve (ICN). CONCLUSIONS: The strengthening of previously subthreshold synaptic connections in a CNS network connecting ICN to MCN or MPN neurons may underlie changing excitability.

Adult↗
PubMed1997

Prolonged duration of standing up is an early dopa-sensitive abnormality in Parkinson's disease.

We studied the influence of dopaminergic medication on the duration of standing up, static posture and gait in five patients with Parkinson's disease (Hoehn and Yahr stage 1.5 to 3) and four healthy controls, using an optoelectronic camera system. Duration of standing up was prolonged in patients, while static posture and gait were largely unaffected. The prolonged duration of standing up was corrected by dopaminergic medication. These results suggest that an increased duration of standing up is a relatively early and dopa-sensitive abnormality in Parkinson's disease.

Aged↗
PubMed1997

Startle responses in hereditary hyperekplexia.

BACKGROUND: Patients with hereditary hyperekplexia have excessive startle responses that are accompanied by transient stiffness and also continuous stiffness in infancy. A point of mutation has been identified for the major form of hereditary hyperekplexia in the gene encoding the alpha 1 subunit of the glycine receptor. OBJECTIVE: To measure startle reflexes and autonomic responses in the major form of hereditary hyperekplexia in the original Dutch pedigree. DESIGN: Startle reflexes and autonomic responses were examined by administering 3 series of 20 auditory stimuli at intervals of 10 seconds (90 and 113 dB) and 60 seconds (113 dB). SETTING: The Department of Neurology and Clinical Neurophysiology at the Leiden University Hospital, Leiden, the Netherlands. SUBJECTS: Nine patients with the major form of hyperekplexia and 20 healthy controls. Of the 9 patients, 5 took medication. The patients are part of the Dutch hyperekplexia pedigree. MAIN OUTCOME MEASURES: Startle responses were quantified with latency periods and areas of electromyographic bursts of the orbicular muscle of the eye, sternocleidomastoid and biceps muscles, and the thenar muscles. Autonomic reactions were measured with psychogalvanic responses and beat to beat changes of blood pressure and heart rate. RESULTS: The electromyographic bursts of the 4 muscles occurred in similar order in both patients and controls. The onset of the latency periods in the patient group was significantly (P < .001) prolonged in patients who took medication. Without medication, patients had shorter latency periods of the sternocleidomastoid muscle (P = .003) than controls. The electromyographic burst occurred significantly more often in patients than in controls (P < .001). The areas of the bursts were significantly larger in patients than in controls (P < .001); the degree of habituation was significantly stronger in patients than in controls (P < .001). The amplitude of the psychogalvanic response was increased in hyperekplexia, and the degree of habituation was significantly weaker in patients than in controls. Blood pressure and heart rate did not clearly react in either group. CONCLUSIONS: Motor startle responses are stronger and show more habituation in patients with hereditary hyperekplexia than in controls. The excessive responses include the psychogalvanic response. Increased responses do not necessarily indicate decreased habituation in hyperekplexia.

Acoustic Stimulation↗
PubMed1997

The effects of clonazepam and vigabatrin in hyperekplexia.

Hyperekplexia is an autosomal dominant disorder caused by a point mutation in the alpha1 subunit of the glycine receptor, characterized by excessive startle responses followed by temporary generalized stiffness. Clonazepam, effective in open case studies, potentiates, through unknown mechanisms, the neurotransmitter gamma-aminobutyric acid (GABA). Vigabatrin increases GABA by inhibition of the GABA catabolic enzyme GABA-transaminase. Effects of clonazepam (1 mg for 1 day) and vigabatrin (1000 mg per day for 5 days) were investigated in a double-blind placebo-controlled cross-over study in 4 patients with hyperekplexia. The pharmacodynamic parameters were startle reflexes, studied 3 times during the day. At each time, 2 trains of 10 auditive stimuli (113 dB) were given at intervals of 10 and 60 s. Startle movements were quantified with summed areas of EMG-bursts of the orbicularis oculi, sternocleidomastoid, biceps and thenar muscles. The degrees of stiffness and drowsiness were quantified with visual analogue scores (VAS) 10 times during the day, by both the patient and the observer. Clonazepam, but not vigabatrin, reduced startle activity significantly in both paradigms. The degree of stiffness and drowsiness was not significantly influenced by either drug.

Acoustic Stimulation↗
PubMed1997

Hyperekplexia-like syndromes without mutations in the GLRA1 gene.

Hyperekplexia (MIM: 149400), or startle disease, is an autosomal dominant neurological disorder characterized by an extreme generalized stiffness immediately after birth, normalizing during the first years of life. Other features of this disorder are excessive startle reactions to unexpected, particularly auditory, stimuli together with a short period of generalized stiffness during which voluntary movements are impossible. Linkage analysis mapped a gene for this disorder to chromosome 5q33-q35. Subsequently, mutations in the GLRA1 gene encoding the alpha 1-subunit of the glycine receptor proved to be causally related to the disease. In the present study, mutation analysis of all exon and flanking intron sequences of this gene was performed in sporadic patients and their parents. Moreover, a branch of the original Dutch hyperekplexia family with a very severely affected individual was screened for an additional mutation in the GLRA1 gene. Except for two polymorphisms, of which one results in an amino acid change, no potentially disease causing mutations were found in the alpha 1-subunit of the glycine receptor. Together with haplotype analysis these results exclude a recessive inheritance or new mutation etiology in these hyperekplexia-like syndrome and emphasize that hyperekplexia-like syndromes can be caused by other genetic factors. The involvement of other genes encoding subunits of the functional glycine receptor complex has not been excluded.

Adult↗
PubMed1997

Sleep scoring at a lower resolution.

Sleep scoring of whole-night polysomnograms is labor intensive. Scoring fewer epochs saves labor at the cost of accuracy; this study investigates the trade-off between the two. Whole-night sleep measures of 12 patients with sleep apnea syndrome, 10 patients with narcolepsy, and 35 controls were first computed using conventional successive 30-second epochs. Using the resulting list of sleep stages, a variable number of epochs was skipped among remaining epochs; the measures were recomputed for the reduced lists. The Bland-Altman analysis was used to define the agreements among the sleep measures at the conventional resolution and those at the lower resolutions. Scoring one-half to one-third of the number of epochs changes the duration of sleep stages only up to 2.5% and 5%, respectively, for all groups and sleep stages. In apnea patients, rapid eye movement (REM) latency deviates < 15 minutes when half of the epochs are scored. In controls and narcoleptics, much lower resolutions can be used before reaching the same level. Potential restrictions for the application of the method are discussed.

Adolescent↗
PubMed1997

Evolution of epilepsy and EEG findings in Angelman syndrome.

PURPOSE: To evaluate the evolution of epileptic seizures and EEG features in a large group of patients with Angelman syndrome (AS). METHODS: Thirty-six patients with AS with a proven chromosome 15q11-13 deletion were retrospectively analyzed with regard to their epilepsy and EEG findings by examination of patient files and EEGs. AIJ EEGs were reviewed by one of the authors. A logistic regression model, with a follow-up from 1 to 39 years (mean, 15 years), was used for statistical analysis. RESULTS: Epileptic seizures had occurred in 30 (83%) patients. In 43% of them, the initial symptoms of epilepsy were febrile convulsions in infancy. In childhood, epilepsy could start with almost any type of seizure. Atypical absences and myoclonic seizures prevailed in adulthood. Epileptic seizures were present in 92% of the adult patients. The most typical EEG findings were rhythmic triphasic delta waves of high amplitude with a maximum over the frontal regions, identified in 99 (66%) of 150 EEGs, and continuously or intermittently, in 30 (83%) of 36 patients with AS. In 47% it was present even before a clinical diagnosis of AS was considered. High-amplitude rhythmic 4-6/s slow activity, seen in 44 (29%) of 150 EEGs, was not present after the age of 12 years. CONCLUSIONS: In contrast to previous reports suggesting a decreasing frequency of epileptic seizures with age, we found that 92% of the adult patients with AS continued to have epileptic seizures. The most typical EEG finding in AS, in both children and adults, was the presence of frontal triphasic delta waves. In mentally retarded patients, this EEG pattern should point the physician in the direction of AS.

Adolescent↗
PubMed1997

Interictal cortical excitability to magnetic stimulation in familial hemiplegic migraine.

We studied interictal cortical excitability with magnetic stimulation in controls, in patients with migraine with aura, and in patients with familial hemiplegic migraine (FHM), in which ictal hemiparesis occurs. Amplitudes (p < 0.05) and amplitude ratios (p < 0.01) revealed heightened excitability in migraine with aura when compared to controls. In patients with FHM, mean thresholds were higher (p < 0.001) and conduction times longer (p < 0.01) than in controls. In FHM, amplitudes were lower on the ictally paretic side of the body than on the other (p < 0.05). Patients with FHM may have increased interictal cortical excitability, complicated by decreased excitability of the affected side.

Adolescent↗
PubMed1996

Nerve grafting from spinal cord to spinal nerve: a microsurgical technique in cats.

A ventral surgical approach is described for the grafting of autologous saphenous nerves between the spinal cord and the avulsed C7 ventral root in the cat. To overcome serious blood loss from the epidural venous plexus, the cats were hyperventilated (end tidal PCO2 to about 23 mmHg) and controlled hypotension was induced (mean arterial pressure to about 60 mmHg). After selective avulsion of the ventral rootlets C7 the saphenous grafts were implanted into the spinal cord and coaptated to the avulsed spinal nerve. The combination of advanced anesthetic methods and microsurgical techniques appeared to be mandatory to achieve a low surgical mortality. Regenerated axons were retrogradely traced using retrograde horseradish peroxidase (HRP), and their functional recovery was evaluated by means of electrophysiological methods.

Anesthesia↗
PubMed1996

The startle pattern in the minor form of hyperekplexia.

BACKGROUND: The major and minor forms of hereditary hyperekplexia (HE) are characterized by excessive startle responses, which are accompanied by transient stiffness only in major HE; patients with major HE also have continuous stiffness during infancy. A point mutation has been identified for major HE in the gene encoding the alpha 1 subunit of the glycine receptor but not for minor HE. OBJECTIVE: To measure startle reflexes and autonomic responses in the major and minor forms of HE in the original Dutch HE pedigree. DESIGN: Startle reflexes and autonomic responses were studied with 3 series of 20 auditory stimuli with intervals of 10 seconds (at 90 and 113 dB) and 60 seconds (at 113 dB). SETTING: A university hospital neurologic department. PATIENTS: Four patients with minor and 9 patients with major HE (patient groups) (a part of the Dutch HE family pedigree) and 20 healthy controls (control group). MAIN OUTCOME MEASURES: Startle movements were quantified with latencies and areas of electromyographic bursts of the following 4 muscles: the orbicular muscle of the eye, the sternocleidomastoid muscle, the biceps muscle of the arm, and thenar muscles. Autonomic reactions were measured with psychogalvanic responses. RESULTS. The 4 muscles contracted in similar order in the groups. The onset latencies of the orbicular muscle of the eye, the sternocleidomastoid muscle, and the biceps muscle of the arm were significantly prolonged in patients with minor HE (P < .006). The frequencies of occurrence of the electromyographic bursts were not different in the minor HE and major HE groups, but they were significantly higher in both patient groups compared with those in the control group (P < .001). The magnitude of the startle responses did not differ between the 2 patient groups (P = .4), but it was larger in both patient groups than in the control group (P < .001). Startle habituation in the minor HE group was much weaker than in the major HE group (P < .001) or in the control group (P < .001). The size of psychogalvanic responses (P = .1) and the degree of habituation (P = .24) in the minor HE group did not differ from those in the major HE group. Compared with that in the control group, the size of psychogalvanic responses in the minor HE group was larger (P < .001) and they habituated stronger (P < .001). CONCLUSIONS: The differences in the startle pattern between major HE and minor HE agree with the clinical and genetic findings: only major HE constitutes part of the HE phenotype. The cause of the minor HE is, as yet, unknown.

Adult↗