Biomedical subjects

T W van Weerden

Publications and source records attributed to T W van Weerden.

At least 19 recordsLinked to original sources

PubMed1995

Unique myoclonic pattern in corticobasal degeneration.

We describe two similar patients with a clinical diagnosis of corticobasal ganglionic degeneration (CBGD). After a period of increased action tremor, both patients developed a fixed posture in the right arm with a slow rhythmic myoclonus, which appeared to be caused by trains of highly synchronized and stimulus sensitive myoclonic discharges. Resetting of the spontaneous myoclonic discharges by peripheral and central stimulation and a jerk-locked cortical potential were demonstrated in one case. The somatosensory evoked potentials (SEPs) showed abnormal parietal curves with small N20-P25 amplitudes and without giant SEP characteristics. The latencies of the cortical event and of the late responses, and the duration and distribution of the discharges compare best with those of the cortical reflex type of myoclonus. Localized parietal cortical damage, as indicated by clinical evidence and imaging techniques, may well explain the absence of a giant SEP in these patients with CBGD.

Aged↗

PubMed1995

Hereditary myokymia and paroxysmal ataxia linked to chromosome 12 is responsive to acetazolamide.

A sixth family with autosomal dominantly inherited myokymia and paroxysmal ataxia is described. The syndrome in this family is linked to the recently discovered locus for inherited myokymia and paroxysmal ataxia on the human chromosome 12p, and a missense mutation is shown in the KCNA1 gene. The attacks of ataxia in this family compare well with those of previously described families and similarly are precipitated by kinesigenic stimuli, exertion, and startle. Responsiveness of these attacks to low dose acetazolamide is confirmed, but some loss of efficacy occurs with prolonged treatment, and side effects are notable. Although not all affected family members showed myokymia on clinical examination, electromyography invariably showed myokymic discharges, in one patient only after a short provocation with regional ischaemia. One affected family member also had attacks of paroxysmal kinesigenic choreoathetosis, responsive to carbamazepine.

Acetazolamide↗

PubMed1994

Muscle fiber conduction velocity in the diagnosis of familial hypokalemic periodic paralysis--invasive versus surface determination.

Muscle fiber conduction velocity (MFCV) in the brachial biceps muscle was determined in a large family of patients with hypokalemic periodic paralysis (HOPP) by both a surface and an invasive method. Other surface EMG parameters and the muscle force were also determined. Both the surface and the invasive method showed a significantly lower mean MFCV in the proven gene carriers but only the invasive method showed a lower MFCV in all proven carriers. It can be concluded that MFCV determination is a reliable method to detect the membrane defect in HOPP carriers and that the invasive method is not only easy to perform, but also more sensitive. The muscle force and the integrated EMG at maximal voluntary contraction were lower in the carrier group. A positive correlation between the surface MFCV and the neuromuscular efficiency (the quotient of force and integrated EMG) was found in the controls but not in the HOPP carriers. Since type II fibers have a higher neuromuscular efficiency, this suggests a preferential involvement of type II fibers in HOPP.

Adolescent↗

PubMed1994

Idiopathic spasmodic torticollis: a survey of the clinical syndromes and patients' experiences.

We evaluated the medical and psychosocial experiences of 59 patients with idiopathic spasmodic torticollis (ST) by means of a structured questionnaire. The results generally corresponded with those of other studies in the literature. Diagnosis is delayed in many patients, and ST negatively influences the patients' social lives. Because drug treatment and physiotherapy are only of sufficient value in a minority, most patients seek benefit from numerous other therapies, none of which has been shown to improve ST.

Adolescent↗

PubMed1990

Familial paroxysmal kinesigenic ataxia and continuous myokymia.

A large family with paroxysmal ataxia and continuous myokymic discharges is described. The disorder is of autosomal dominant inheritance. During attacks coordination of movements and balance are disturbed; often a postural tremor of the head and the hands and fine twitching in some of the facial and hand muscles are present. The attacks usually last a few minutes and may occur several times per day. They first appear in childhood and tend to abate after early adulthood. The attacks are frequently precipitated by kinesigenic stimuli similar to those in paroxysmal kinesigenic choreoathetosis. Their occurrence can be reduced or prevented by carbonic anhydrase inhibitors. Between attacks a slight postural tremor and ataxia was found in a few of the elderly affected members. Fine rippling myokymia was obvious in a few and could be detected on close inspection in about half of the adults. Electromyography (EMG) showed myokymic discharges in all affected members. The characteristics and reactivity of this myokymic activity suggest multiple impulse generation in the peripheral nerves.

Acetazolamide↗

PubMed1989

Transient paresis in myotonic syndromes. A surface EMG study.

In order to study transient paresis, force and surface electromyograms (EMG) were recorded from the biceps brachii in 3 patients with recessive myotonia congenita, in 8 with myotonic dystrophy and in 3 controls. Epochs of 0.34 s EMG signal were stored every 0.44 s and processed to determine the integrated EMG (IEMG), the power spectrum and the average muscle fibre conduction velocity (MFCV). The protocol consisted of 5 maximal voluntary contractions lasting 10.3 s and 13 s recovery. During the first 1-1.5 s the MFCV and median frequency (Fmed) of the power spectra of the controls increased (mean increase 12.5% and 14%, respectively) in all 5 consecutive contractions. Subsequently, MFCV, Fmed and force declined as a consequence of fatigue. Both the initial force and MFCV declined with successive contractions. The results in myotonic dystrophy were not different from the controls, except that the changes during fatigue were far less pronounced. These events are the reverse of the changes found in myotonia congenita in which an initial loss of force (maximal by 61-79%) and a decline of the IEMG (maximal by 79-92%) was found during the first contraction. This transient paresis was accompanied by a dramatic fall in the MFCV concomitant with a shift of the power spectrum to the lower frequencies. The first MFCV measurement of the 5 contractions was always normal. The decline in MFCV was maximal after 1.5-2.5 s and varied for the 3 patients from 32-52%. In general, the decline in force, IEMG and MFCV lessened with each successive contraction (warming-up phenomenon), though sudden deteriorations were sometimes observed during later contractions. The same results were found for brachioradialis and abductor digiti minimi. The results provide evidence that transient paresis is of clinical relevance in myotonia congenita and that it is caused by alterations in the muscle membrane. These membrane changes result in a strong decline of the muscle action potential conduction velocity and consequent depolarization block of the muscle fibres. Our method did not show the presence of transient paresis during voluntary contraction in myotonic dystrophy.

Adult↗

PubMed1988

Ultrasonography of the peroneal nerve muscle group in normal subjects and patients with peroneal paresis.

A method for measuring the cross-sectional area (CS area) of the peroneal nerve muscle groups (PNMG) by ultrasonography is presented. The method has a good reliability and can be performed easily. The mean value of the ratio (x 100) of the right-sided PNMG CS area to the left-sided PNMG CS area in right-handed normal subjects was 98%, with a standard deviation of 8.5%. The normal range for this value was 81%-115% (mean +/- 2 SD). Examples of these measurements in patients with peroneal pareses during denervation and reinnervation are given.

Adult↗

PubMed1988

The muscle fiber conduction velocity and power spectra in familial hypokalemic periodic paralysis.

Surface EMG has been used to determine the average muscle fiber conduction velocity (MFCV) and power spectra of the m. biceps of 10 patients and 15 asymptomatic offspring of a large kinship with familial hypokalemic periodic paralysis (HOPP). The MFCV of the patients was 3.37 +/- 0.35 m/sec (mean +/- SD, n = 9), the median frequency (Fmed) of the power spectra was 55.0 +/- 5.8 Hz (mean +/- SD, n = 9), both values are significantly (P0.001, Student's t-test) lower than the control values: MFCV = 4.55 +/- 0.33 m/sec; Fmed = 88.6 +/- 15.5 Hz (mean +/- SD). In 6 of the 15 asymptomatic relatives, the surface EMG results were also abnormal. It is concluded that the MFCV is reduced in familial HOPP. This results in a predominantly low-frequency content of the power spectra, thereby providing a new model for studying the relationship between the MFCV and the frequency spectrum of surface EMG. Asymptomatic relatives that have inherited the disease probably can be detected with this method.

Adult↗

PubMed1987

Meige syndrome: double-blind crossover study of sodium valproate.

A double-blind crossover study of sodium valproate and placebo was conducted in five patients with Meige syndrome. CSF neurotransmitter studies were performed at the end of each treatment period. GABA levels were not influenced by the administration of sodium valproate. An increase in HVA levels was observed in every patient, which may reflect an increase in central dopaminergic activity. This finding may explain the trend towards clinical deterioration which was observed during treatment with sodium valproate. Sodium valproate appears to be ineffective in Meige syndrome.

Basal Ganglia Diseases↗

PubMed1987

The effect of low-frequency electrical stimulation on denervation atrophy in man.

The effect of low frequency electrical stimulation (LES) on denervation atrophy and recovery of the muscles was examined in a group of 73 patients with a single or a combined total lesion of the median, ulnar or peroneal nerves. The differences between the patients were evaluated by means of clinical muscle force testing, EMG, dynamometry (ulnar and median nerve lesions), computer tomography (ulnar nerve lesions) and ultrasonography (median and peroneal nerve lesions). A beneficial effect of LES could not be shown.

Adolescent↗

PubMed1986

Hereditary congenital external ophthalmoplegia.

Several members of a large pedigree suffering from hereditary congenital external ophthalmoplegia, an autosomal hereditary disorder of ocular movements, were examined and surgically treated. From nystagmographic findings it was concluded that the main cause of this disorder is of supranuclear origin. Specimen of the inferior oblique muscle revealed no abnormalities or showed decrease of type I muscle fibers.

Adult↗

PubMed1985

Ocular dipping.

Explore the source record for details and available documents.

Arousal↗

PubMed1984

Saccadic oscillations associated with the quick phases of caloric nystagmus in severe diffuse brain damage.

Caloric nystagmus patterns associated with ocular dysmetria, ocular flutter or flutter dysmetria were studied in ten patients being in a vegetative state, among whom were 9 patients with head injury and 1 with complications caused by a grand mal status. Brain damage was complicated by hypoxemia and especially by brain stem herniation. It was more often observed in very young children and appears to be associated with a poor clinical course. Physostigmine seems to have an activating and provocating effect on these saccadic oscillations. In view of Zee and Robinson's hypothesis on the pathophysiology of saccadic oscillations, it is suggested that these nystagmus patterns may reflect a disturbance of brain stem midline structures (pausing neurons) or an abnormal supranuclear (cerebellum) control.

Adolescent↗

PubMed1984

Axial apraxia, a distinct phenomenon.

Three Parkinson patients who continued to have difficulties with turning in the horizontal plane despite adequate and therapeutically effective levodopa treatment are presented. The handicap of the disordered axial rotation, to be considered an elementary displacement of the body, could be alleviated by alternative motor strategies or overcome by specific extra stimuli or tactile guidance but not physiotherapeutically restored. On the basis of these clinical observations it is argued that these axial movement abnormalities are apraxic.

Adult↗

PubMed1984

Spasmodic torticollis: treatment with Tizanidine.

A randomized double-blind cross-over study was performed to compare the efficacy of Tizanidine to that of placebo in the treatment of spasmodic torticollis. No evidence was found that Tizanidine was effective in 10 patients with spasmodic torticollis who received Tizanidine during 6 weeks, up to a dose of 12 mg a day.

Adolescent↗

PubMed1984

Manifest latent nystagmus of late onset: a case report.

A case of manifest latent nystagmus of late onset in a 13-year-old girl is reported. The nystagmus became manifest during the development of a hypertropia of the left eye. The spontaneous nystagmus was successfully treated by surgical correction of the hypertropia. The observations are discussed with regard to theories on the origin of latent nystagmus.

Adolescent↗

PubMed1983

Inferior and superior gluteal nerve paresis and femur neck fracture after spondylolisthesis and lysis: a case report.

A 33-year-old woman is presented with spondylolisthesis of L4 on L5 with osteolysis of the L4 vertebra, left-sided superior and inferior gluteal nerve paresis and a fracture of the neck of the left femur. The gluteal muscle paresis was thought to be caused by an entrapment of the gluteal nerves through the piriformis muscle, as a consequence of the lumbar lordosis and inadequate stabilization of the back. The femoral fracture was explained by lack of the compensating action of the paretic gluteal muscles, through which an abnormal strain on the femoral neck occurred while climbing a staircase. Innervation disturbance of the superior part of the femoral neck, which is normally innervated by the superior gluteal nerve, might also be a causative factor in the occurrence of this fracture.

Adult↗

PubMed1982

Ocular dipping.

Ocular dipping consists of cycles of eye movements occurring spontaneously, which are characterized by a slow conjugated downward deviation followed after a delay by a quick return to mid position. Ocular dipping is only described in unconscious patients, especially in anoxic comata. Three new patients with this syndrome are described. Electronystagmographic registrations are shown.

Adolescent↗