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Biomedical subjects

M Dieterich

Publications and source records attributed to M Dieterich.

103 records · Page 6Linked to original sources

Psychogenic disorders in neurology: frequency and clinical spectrum.

Among 4470 consecutive neurological inpatients presenting "with typical neurological symptoms" 405 (9%) were found to have psychogenic rather than neurological dysfunction of the nervous system as the primary cause of admission. This probably represents a conservative figure, since secondary and minor pseudoneurological symptoms were not included. Retrospective analysis of these cases showed that pain was the most common psychogenic symptom, followed by motor symptoms (in particular stance and gait disturbances), dizziness, psychogenic seizures, sensory symptoms, and visual dysfunction. Unilateral motor and sensory symptoms were equally distributed to the left and right side of the body. Psychiatric abnormalities in these patients were heterogenous. Depressive syndromes were most common (38%), whereas hysterical features were less frequent than expected (9%). On discharge, improvement was significantly better for patients with recent onset of symptoms (2 weeks or less) than for those with longstanding disturbances. Short-term outcome was best for motor symptoms and worst for pain. Improvement was independent of psychiatric findings, coexistence of a neurological disease, age, and sex.

Adult↗

Tonic contraversive ocular tilt reaction due to unilateral meso-diencephalic lesion.

We studied 4 patients with tonic contraversive ocular tilt reactions due to unilateral, paramedian, mesodiencephalic lesions. This is in contrast to the only 2 previously reported patients with ocular tilt reactions due to unilateral mesodiencephalic lesions, each of whom had a paroxysmal ipsiversive ocular tilt reaction. This new finding is considered in the context of previous clinical and experimental data on the various types of ocular tilt reactions that follow stimulation or destruction of the peripheral and central vestibular system. Otolithic inputs to the interstitial nucleus of Cajal from the contralateral vestibular nucleus and motor outputs from the interstitial nucleus of Cajal to cervical and ocular motoneurons could be involved in the ocular tilt reaction. We propose that in patients with unilateral meso-diencephalic lesions, a tonic contraversive ocular tilt reaction could be due to persistently decreased resting activity of ipsilateral interstitial nucleus neurons, whereas a paroxysmal ipsiversive ocular tilt reaction could be due to transiently increased activity of the same interstitial nucleus neurons. Cases of ocular tilt reaction due to unilateral meso-diencephalic lesion point to the existence of a crossed graviceptive pathway between the vestibular nucleus and the contralateral interstitial nucleus of Cajal.

Adult↗

Otolith function in man. Results from a case of otolith Tullio phenomenon.

An otolith disorder is described in a patient with a subluxed stapes footplate. Otoneurological examination, including tympanoscopy, showed that nonphysiological mechanical stimulation of the otoliths by a (pathologically) hypermobile stapes footplate typically manifests with a pattern of sound-induced paroxysms of ocular tilt reaction (OTR), oscillopsia and postural imbalance (otolith Tullio phenomenon). The rare condition of sound-induced otolithic stimulation in an otherwise healthy young man offered a unique opportunity to investigate otolith reflex control of the eye, head and posture in man. Electro-oculographic recordings and special video analysis (time resolution: 1000 images/s) revealed an initial rapid and phasic counterclockwise rotatory upward deviation with a latency of 22 ms, followed by a smaller tonic effect which lasted as long as sound stimulation (480 +/- 20 Hz, 95 dB A). Latencies of the otolithic vestibulospinal reflex, recorded using surface EMG during upright stance with the eyes closed, were surprisingly short with activation of the ipsilateral tibialis anterior muscle 47 ms after the stimulus, and of the ipsilateral gastrocnemius muscle after 52 ms. A considerable postural pertubation was measured by means of a Kistler platform, with the shortest latency for displacement of the centre of pressure of 80 ms and a preferred body sway direction from right-backward to left-forward. When the Valsalva manoeuvre was performed, tonic eye movements and oscillopsia were induced opposite in direction to those produced by the sound reflecting a push-and-pull deviation of the otoliths.

Adult↗

Incidence of post-lumbar puncture headache is independent of daily fluid intake.

The clinical practice of advising patients to increase their daily fluid intake after lumbar puncture in order to increase CSF production by re-hydration and thus try to prevent post-lumbar puncture headache (PLPH) has not yet been shown to be effective. In 100 patients the different effects of re-hydration on the incidence of PLPH (1.51 compared with 3.01 oral fluid per day over a period of 5 days) were tested prospectively. The incidence of PLPH was independent of the amount of fluid intake in both groups (18, 36%), as was the duration of PLPH. The physiology of CSF production and resorption suggests that PLPH is not a problem of CSF dynamics but a simple mechanical problem of how to close the dural rent and thereby stop the continuous leakage. It is no longer justifiable to advise patients to drink more than usual since there is no physiological or empirical basis for this and it does not seem to have even a placebo effect.

Adolescent↗

Pathological eye-head coordination in roll: tonic ocular tilt reaction in mesencephalic and medullary lesions.

The fundamental pattern of coordinated eye-head roll motion is based upon utricular/saccular as well as vertical canal input, and mediated by the graviceptive pathways from the labyrinths via pontomedullary vestibular nuclei to the rostral midbrain tegmentum. The tonic bilateral graviceptive input stabilizes the eyes and head in the normal upright position. A unilateral lesion causes imbalance in vestibular tone in the roll plane which results in a tonic ipsiversive ocular tilt reaction (OTR). OTR, the triad of ipsilateral head tilt, skew deviation and ocular torsion, occurred as a tonic response (nonparoxysmal) persisting over months to years and was presumed to be due to upper brainstem lesions in 3 patients. Precise localization was limited because of the nature of the lesions. A reversible tonic OTR was seen with acute infarction of the dorsolateral medulla oblongata in 4 out of 11 patients. It may be explained by an ipsilateral lesion of the posterior canal pathways. Transient OTR seems not to be rare in acute Wallenberg's syndrome and ocular torsion in these patients is dysconjugate with predominant excyclotropia of the ipsilateral hypotropic eye. A deviation of the subjective visual vertical in the direction of the spontaneous head tilt--a previously undescribed feature of OTR--was present in all 7 patients and indicates a pathological shift of the internal representation of the gravitational vector. With respect to perception (subjective vertical) it is proposed that the manifest ipsiversive OTR represents a motor compensation of an apparent eye-head tilt contraversive to the lesioned side. Despite the resulting postural imbalance and the conflicting true vertical of the visual surround, the eyes, head and body are continuously adjusted to what the central nervous system erroneously computes as being vertical.

Adult↗

Is obligatory bed rest after lumbar puncture obsolete?

After lumbar puncture (LP) an epidural CSF leakage caused by delayed closure of a dural defect leads to a decrease in CSF pressure. The resultant venous dilatation as well as downward shift of the brain with traction on pain-sensitive blood vessels and nerves frequently evokes post-lumbar puncture headache (PLPH), when the patient assumes the upright position. In previous studies differing opinions have been expressed about the prophylactic value of the posture taken by the patient after LP. The present study was designed to evaluate the benefit of the decrease of hydrostatic CSF pressure on the dural rent, when the patient lies down in a prone position with the head tilted down at an angle of 10 degrees for 30 min immediately after LP: is it possible to accelerate the closure of the dural defect in this way and prevent PLPH? One group of patients (n = 78) lay in a prone position with the head tilted down at an angle of 10 degrees for 30 min, the other group (n = 82) rose immediately after LP. PLPH was found to be independent of the posture in both groups and affected 44% and 41% of the patients, respectively, so that there is no longer any justification for requiring patients to remain in bed after LP.

Adolescent↗

The vocational integration of the mentally retarded: a program to develop vocational maturity.

In many countries there are minimum standards for entry into vocational training programs, but until now there has been no instrument for determining whether retarded applicants possess the motor skills required to enter and complete such programs. To construct such an instrument, experts representing most of the skilled vocations in West Germany were consulted about typical skills required during the vocational education in their fields. Based on their responses, a catalog of essential skills was compiled and testing procedures (Handwerklich-Motorischer Eignungstest HAMET) were developed to determine vocationally-oriented motor skills for use in diagnostic and remedial programs for the retarded. A test administered to more than 100 mentally retarded youth showed significant and typical deficiencies in motor skills compared with those of non-retarded individuals. By using a factor analysis of the HAMET-items, it was possible to isolate elementary motor functions which are common to all the skilled vocations. Knowledge of these factors made it possible to start one-year training courses to develop vocational maturity. With selected exercises based on the HAMET-items the courses were very successful. In contrast to traditional programs for the mentally retarded it could also be shown that frequent changes of workshops and of vocational education staff are not necessary and that the entire training program can be carried out in one equipped workshop.

Adolescent↗

Can short-latency vestibulospinal reflexes in lower leg muscles be elicited by tapping the head?

A gentle tap on the forehead evoked short-latency motor responses in the sternocleidomastoid muscle, which may be vestibulocollic reflexes with characteristics similar to those elicited by clicks. We tested this paradigm in subjects standing upright, in order to determine the differential effects of taps on the forehead on the patterns and latencies of spinal stretch and vestibulospinal reflexes, which are important for postural control. Taps on the forehead elicited short-latency inhibitory electromyographic responses in both gastrocnemius muscles with a mean latency of 48.3 +/- 3.1 ms (onset) to 98.3 +/- 6.3 ms (end). Taps on the sternum elicited similar responses from the gastrocnemius muscles, indicating that vestibular stimulation is not essential for eliciting these responses. Both responses may play a role in predetermining the strategy for correcting body perturbations. The actual reflex is probably elicited by somatosensory input from the neck, which converges with vestibular input for the multisensory control of posture.

Acceleration↗

Multivariate analysis of prognostic features in malignant pleural effusions from breast cancer patients.

To identify prognostic indicators in breast cancer patients with malignant pleural effusions, we analyzed the cytopathologic features of 57 fluids representing the first pathologic diagnosis of a distant metastasis in these women. The specimens were analyzed prior to reviewing the clinical records. The median survival of 55 patients who died of the disease was five months following the effusion diagnosis (range, 1-114). Univariate analysis identified three cytopathologic features that correlated with relatively prolonged survival: arrangement of tumor cells in spheroids, slight nuclear atypia and low mitotic rate. Women whose tumor cells formed spheroids survived a median of 24.5 months as compared to 4 months for women with all other architectural patterns (P = .004). Multivariate analysis revealed that slight nuclear atypia and low mitotic rate strongly correlated with spheroid formation. Since breast cancers that form spheroids in effusions portend a relatively favorable prognosis, we recommend that cytopathologists comment on this pattern when reporting on metastatic breast carcinoma in pleural fluids.

Adult↗