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Biomedical subjects

J Dichgans

Publications and source records attributed to J Dichgans.

At least 235 records · Page 13Linked to original sources
PubMed1991

Ergotamine, flunarizine and sumatriptan do not change cerebral blood flow velocity in normal subjects and migraneurs.

Changes in the diameter of extracranial and intracranial arteries resulting in changes in cerebral blood flow have previously been assumed to be the most important pathophysiological factor in migraine. To test this hypothesis 20 normal subjects, and three groups of patients (n = 29) with migraine were investigated by means of transcranial Doppler sonography. Blood flow velocities in the middle cerebral (MCA) and in basilar (BA) arteries were measured. Data from patients were obtained in the interval between migraine attacks, during migraine attacks and following treatment with either ergotamine (0.5 mg i.m.; n = 10); flunarizine, a calcium overload blocker (20 mg i.v.; n = 13); or a 5-HT1-like agonist (sumatriptan, 4 mg s.c.; n = 6). Ergotamine and sumatriptan are constrictors of cerebral arteries in animal experiments. The arithmetic mean of flow velocity in the BA was reduced in normal subjects (45 cm/s) as compared with patients with migraine measured in between attacks (53 cm/s). Mean flow velocity in MCA was not different in normals (72.5 cm/s) as compared with migraineurs (75 cm/s). Neither ergotamine nor the 5-HT1 agonist and flunarizine resulted in a significant change in blood flow velocity in MCA and BA. This was true irrespective of whether the drugs were given in the headache-free period, during a migraine attack or during the withdrawal phase of drug-induced headache. Ergotamine was effective in improving headache during migraine attacks and sumatriptan attenuated headache during drug withdrawal from chronic analgesic intake. These results indicate that the action of ergotamine and the 5-HT1-receptor agonist is probably not mediated by their vasoconstrictor action on cerebral arteries.

Adult↗
PubMed1991

Superficial siderosis of the central nervous system. A 37-year follow-up of a case and review of the literature.

The course of a patient suffering from superficial siderosis of the central nervous system for 37 years is presented and diagnostic and therapeutic approaches are evaluated. The syndrome is clinically defined by slowly progressing deafness, cerebellar ataxia, myelopathy and neuropsychological deficits in combination with recurrent xanthochromia of the cerebrospinal fluid with siderophages. The diagnosis may be confirmed by computed tomography, which shows degeneration of the cerebellar vermis, and by magnetic resonance imaging, demonstrating iron deposits on the surface of brain, brain stem and spinal cord. Therapy should seek to identify and remove the source of bleeding, since pharmacotherapy with iron-depleting drugs is of limited effectiveness.

Brain Diseases↗
PubMed1991

Neurosarcoidosis without systemic sarcoidosis.

Neurosarcoidosis is a well-recognised complication of systemic sarcoidosis but diagnosis may be difficult if there is no clear evidence of an extracerebral manifestation of the disease. We present the case of a 42-year-old woman with clinical features characteristic of cerebral sarcoidosis including tetraparesis, diabetes insipidus, diencephalic hyperphagia, personality changes, and memory loss. Diagnosis was supported by cerebrospinal fluid (CSF) findings and magnetic resonance imaging (MRI): CSF showed mild lymphocytic pleocytosis, intrathecal production of IgG without oligoclonal bands, and a raised level of lysozyme. MRI revealed multiple contrast-enhanced granulomas at the base of the brain with partial involvement of diencephalic and mesencephalic structures and parts of the spinal cord. There was no evidence of systemic manifestation of sarcoidosis. Administration of corticosteroids led to improvement of the symptoms.

Adult↗
PubMed1991

Comparative analysis of cytokine patterns in immunological, infectious, and oncological neurological disorders.

Interleukins (IL) 1, 2, 4, 6 and soluble IL-2 receptor (sIL-2R), interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha) were measured in CSF and serum from patients with relapsing-remitting and chronic multiple sclerosis, Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, HIV infection, bacterial meningitis, viral encephalitis, meningeal carcinomatosis, hematologic meningeal malignancies, and disseminated melanoma. Our findings suggest that monitoring of disease activity in neuroimmunologic disorders by means of IL-1 beta, IL-2, sIL-2R, or IL-4 determination will not prove useful. IL-6, on the other hand, indicates relapse in multiple sclerosis and active disease in Guillain-Barré syndrome and meningeal carcinomatosis. High CSF TNF-alpha in metastatic melanoma and frequent detection in CSF of the multifunctional B-cell growth factor, IL-6 (27/30) and oligoclonal immunoglobulin bands (33%) in meningeal carcinomatosis confirm an intrathecal immune response in disseminated leptomeningeal neoplasia which might be amenable to therapeutic immunomodulation.

Cytokines↗
PubMed1991

Influence of posture and voluntary background contraction upon compound muscle action potentials from anterior tibial and soleus muscle following transcranial magnetic stimulation.

Compound muscle action potentials (CMAPs) were recorded from anterior tibial (TA) and soleus (SOL) muscles following transcranial magnetic stimulation of motor cortex in 10 healthy subjects: (1) while standing upright without support, (2) while sitting, and (3) while lying supine. The results of this study demonstrate a significant influence of posture upon the amplitudes of CMAPs. Postural facilitation presented itself, firstly, in terms of a higher incidence of bilateral activation of distal leg muscles during stance and, secondly, as significant enhancement of the amplitude of CMAPs while standing as compared to lying supine. The onset latency, however, did not disclose a significant shortening during stance. To assess the effects of preinnervation subjects voluntarily adjusted the level of TA activity to 5%, 10% and 20% of maximum isometric force respectively before cortex stimulation. Voluntary background contraction resulted in a significant increase of amplitude of CMAPs but, in contrast to postural facilitation, concomitant with a significant decrease in onset latency. These results point to a somewhat different mechanism of facilitation during stance as compared to voluntary preinnervation. But it cannot be decided whether cortical mechanisms, different descending systems, the spinal circuitry or a combination of these factors is responsible for the observed effects.

Adult↗
PubMed1991

Early onset cerebellar ataxia with retained tendon reflexes. Clinical, electrophysiological and MRI observations in comparison with Friedreich's ataxia.

Fourteen patients with the clinical diagnosis of early onset cerebellar ataxia with retained tendon reflexes (EOCA) were examined and compared with 11 patients with Friedreich's ataxia (FA). The mean age of onset in EOCA was 15.9 +/- 6.0 yrs (FA: 14.0 +/- 5.7 yrs). Annual progression rate and the percentage of patients who were wheelchair-bound was lower in EOCA as compared with FA, although the difference did not reach statistical significance. The latency until becoming wheelchair-bound, however, was significantly longer in EOCA than in FA. The segregation ratio in EOCA was significantly lower than 0.25. Clinically, EOCA and FA patients presented with a progressive cerebellar syndrome. Associated symptoms, such as muscle wasting, sensory disturbances, foot deformity, scoliosis and electrocardiographic abnormalities were encountered less frequently in EOCA than in FA patients. The electrophysiological findings in EOCA were variable and pointed to axonal degeneration in peripheral nerves and central pathways. Posturographic measurements revealed a higher incidence of anteroposterior sway direction in EOCA as compared with FA, suggesting a cerebellar type of ataxia in EOCA. Eleven out of the 14 EOCA patients had cerebellar atrophy in MRI. The characteristic MRI finding in FA was upper cervical cord shrinkage and only minor atrophy of the cerebellum. The demonstration of cerebellar atrophy in the majority of EOCA patients supports the view that EOCA is distinct from FA. It is uncertain, however, whether EOCA is a homogenous disease entity or a group of phenotypically similar syndromes.

Action Potentials↗
PubMed1991

Subcutaneous sumatriptan in the treatment of headache during withdrawal from drug-induced headache.

In a pilot study (5 patients) we investigated the effects of subcutaneous sumatriptan, a 5-HT1-like receptor agonist, on headache experienced during the withdrawal period of drug-induced headache. The pilot study indicated that the substance was effective mostly in patients who originally suffered from migraine. In a patient with tension headache the substance was less effective. In a second double-blind study on six migraine patients with severe drug-induced headache, the drug was highly effective in ameliorating headache and autonomic disturbances. Blood flow velocities measured in extracranial parts of internal and external carotid arteries by duplex-sonography and in middle cerebral and basilar arteries by transcranial Doppler showed no changes after administration of sumatriptan or placebo. This result suggests sumatriptan does not act primarily via constriction of the large cerebral arteries.

Adult↗
PubMed1991

Myelinoclastic diffuse sclerosis (Schilder's disease): cliniconeuroradiologic correlations.

We report a 17-year-old boy with myelinoclastic diffuse sclerosis (Schilder's disease) presenting with left leg paresis, visual loss, and behavioral changes. CT and MRI showed two large lesions in the subcortical white matter of the occipital and parietal lobes of both hemispheres and increased intracranial pressure. Histology disclosed large areas of demyelination and perivascular infiltrates. The patient improved with coincident oral prednisolone treatment.

Adolescent↗
PubMed1991

[Carotid endarterectomy for prevention of stroke: comparison of surgical and conservative therapy].

The incidence of TIA, stroke and death among 689 patients with a narrowing of the internal carotid artery exceeding 50% was investigated in a follow-up study. Patients were assigned according to their initial status to one of the following groups: asymptomatic, transient ischemic attacks (TIA) and minor stroke. Patients subjected to carotid endarterectomy (n = 206) were compared to those treated by oral medication only. The follow-up time averaged 2.1 years. The incidence of stroke and death among the initially asymptomatic persons was not significantly different in those who underwent surgery (n = 46) and those who did not (n = 234). The incidence of TIA however was significantly higher in the operated patients. Among patients with TIA the incidence of repeated TIA, stroke and death was similar in those who were operated (n = 90) and those who were not (n = 61). The same was true for subsequent TIA and strokes in patients who had suffered from a first stroke prior to the initial examination. Patients who underwent surgery (n = 70) did not differ in this respect from the 188 patients who were not operated on. The death rate, however, was significantly higher in the non-operated patients (24.5% versus 7.2%). Due to the retrospective character of the study, operated and non-operated groups of patients were not directly comparable. We therefore selected comparable groups of patients by a stratification procedure. These subgroups showed no differences in the incidence of TIA and stroke between operated and non-operated patients. The result indicates, that the decision to perform carotid endarterectomy should be made with great caution.

Adult↗
PubMed1990

Central pontine myelinolysis associated with low potassium levels in alcoholism.

Two patients with chronic alcohol abuse and central pontine myelinolysis are described. One developed a Korsakoff syndrome 2 days before admission to our hospital and the other showed signs of a incipient delirium without Korsakoff syndrome. Diagnosis of incipient central pontine myelinolysis was based on acute brain-stem dysfunction, serum electrolyte disturbances, malnutrition with vitamin B1 (thiamine), B6 (pyridoxine) and B12 (cyanocobalamin) deficiency in combination with typical neuroradiological findings. Hypokalaemia but no disturbance in serum sodium levels was found in both patients. After correction of hypokalaemia and vitamin deficiency the patients showed complete recovery of neurological and neuropsychological function. The findings are interpreted as suggesting that disturbances in serum potassium levels as well as rapid correction of hyponatraemia may be associated with pontine swelling and dysfunction which, if undetected, leads to central pontine myelinolysis.

Adult↗
PubMed1990

The development of infratentorial atrophy in patients with idiopathic cerebellar ataxia of late onset: a CT study.

The development of infratentorial atrophy in six patients suffering from idiopathic cerebellar ataxia of late onset was studied by a retrospective evaluation of consecutive computed tomography (CT) scans. Four patients had evidence of olivopontocerebellar atrophy (OPCA) both on clinical testing and magnetic resonance imaging (MRI). In these four patients, atrophy of the cerebellum and brain stem became visible at the same time and progressed in a roughly parallel manner, whereas in the remaining two the brain stem was left intact. In all patients with OPCA, definite brain-stem atrophy was visible earlier than the appearance of non-cerebellar clinical symptoms. The present data suggest that CT investigations at regular intervals may be of prognostic value in cerebellar ataxias.

Adult↗
PubMed1990

Impairment of vertical motion detection and downgaze palsy due to rostral midbrain infarction.

We present two cases with acute onset of vertical gaze palsy, mainly consisting of impaired downgaze and apraxia of downward head movements, together with neuropsychological deficits (hypersomnia, impaired attention and disorders of memory and affective control). CT and MRI revealed bilateral post-ischaemic lesions in the dorsomedial thalamus and the mesodiencephalic junction, dorsomedial to the red nucleus, thus being restricted to the territory of the posterior thalamosubthalamic paramedian artery, which includes the region of the rostral interstitial nucleus of the medial longitudinal fascicle as the main premotor nucleus for the generation of vertical saccades. In our patients, oculographic examination with electro-oculography and magnetic search coil recording showed severe impairment of downward more than upward saccades and only minor deficits of vertical pursuit and the vestibulo-ocular reflex. Visual functions were normal, with one exception: a psychophysical test of motion perception revealed a significant deficit in the detection of vertical movements. This could be due to a central adaptive mechanism which, in order to minimize oscillopsia, might elevate thresholds for vertical motion perception in cases of vertical gaze palsy. As an alternative explanation, lesions within the midbrain tegmentum could have damaged subcortical visual pathways involved in motion perception.

Cerebral Infarction↗
PubMed1990

Aberrant regeneration in a case of syringobulbia: selective co-activation of abducens and facial nerves during saccades.

A patient suffering from syringobulbia and syringomyelia exhibited a phasic contraction of the ipsilateral facial muscles, mainly the levator labii, whenever he looked to the left or right. Facial muscle twitches occurred exclusively with saccades. The selective co-activation of abducens and facial nerves is interpreted as the result of bilateral misrouting of regenerating neurons from the parapontine reticular formation to the facial nerve in the tegmentum pontis.

Abducens Nerve↗
PubMed1990

Opercular syndrome without opercular lesions: Foix-Chavany-Marie syndrome in progressive supranuclear motor system degeneration.

A patient is described with slowly progressive supranuclear motor system degeneration (primary lateral sclerosis) characterized by pure bulbar spasticity for six years until a spastic tetraparesis developed. Clinically and electrophysiologically there was and still is no evidence of lower motor neuron involvement. Recently the patient presented with a syndrome of complete inability to move face and tongue voluntarily with preservation of the ability to move them "automatically", e.g. within gestures: automatic-voluntary motor dissociation. Loss of voluntary innervation of the facio-pharyngo-glossomasticatory muscles with preservation of involuntary innervation are the features of the Foix-Chavany-Marie syndrome, which to date has most often been described in association with bilateral vascular lesions of the opercula or their cortigofugal projections.

Amyotrophic Lateral Sclerosis↗
PubMed1990

Idiopathic cerebellar ataxia of late onset: natural history and MRI morphology.

Twenty eight patients with the clinical diagnosis of idiopathic late onset cerebellar ataxia were examined clinically and by magnetic resonance imaging (MRI) or computed tomography (CT). In addition, the clinical records of all patients were analysed retrospectively. On the basis of their clinical presentation they were subdivided into patients with a pure cerebellar syndrome (n = 9) and patients with a cerebellar syndrome and additional non-cerebellar symptoms (n = 13). No attempts were made to classify patients with a disease duration of less than four years (n = 6) because the retrospective analysis showed that the disease started almost invariably with a pure cerebellar syndrome and additional symptoms came later. Patients with a lasting pure cerebellar syndrome had a significantly better prognosis than patients with additional non-cerebellar involvement (annual progression rate rate: 0.40 versus 0.80). Calculated median lifetime from onset of symptoms was 20.7 years in patients with a pure cerebellar syndrome and 7.7 years in patients with additional non-cerebellar symptoms. Among the latter, disease progression was faster the earlier non-cerebellar symptoms occurred. All of them presented with Parkinsonian symptoms, whereas bulbar symptoms, vertical gaze paresis, pyramidal deficits, dementia and urinary incontinence were encountered less frequently. MRI or CT showed cerebellar atrophy without apparent involvement of brainstem structures in all patients with a pure cerebellar syndrome suggesting the diagnosis of cerebellar cortical atrophy (CA). The majority of the patients with additional non-cerebellar symptoms had evidence of an atrophy of the cerebellum and the brainstem suggesting the presence of olivo-ponto-cerebellar atrophy (OPCA). In two of them, however, MRI morphology was not compatible with the diagnosis of OPCA.

Adult↗
PubMed1990

Associated postural adjustments with body movement in normal subjects and patients with parkinsonism and cerebellar disease.

Sequential postural adjustments associated with the task of rising on tip-toes were investigated in a reaction time paradigm in 30 normal subjects, 10 patients with Parkinson's disease and 2 patients with cerebellar lesions. The typical motor pattern observed in normal subjects consists of preparatory activity in tibialis anterior (TA, shifting the body forward) and quadriceps femoris (QUA, stabilizing the knee joint) followed by executional activity in triceps surae (TS) resulting in the movement itself. Shortening of TS without preparation would result in shifting the body backward and in flexion of the knee. The coordinated pattern of motor activities is obviously adapted to functional demands. Leaning forward or backward prior to the movement results in additional adaptive changes in the timing of preparatory versus executional EMG activity, and in the amount of preparatory muscle force. The basic pattern of preparatory (TA and QUA) and executional (TS) activity was preserved in most patients with Parkinson's disease. Reaction times were normal or only moderately delayed. Time intervals between postural preparation and execution were also normal. But trial to trial variation of reaction times was increased. In the two patients with cerebellar disorders, motor preparation in QUA was delayed beyond TS onset. EMG activity was tonic and cocontraction of antagonistic muscles occurred. The basic pattern of motor preparation and execution was again preserved. It must therefore be generated outside the basal ganglia and the cerebellum. The temporal coordination of muscular activity within each and between the two components and scaling of muscle force are under cerebellar control.

Adult↗