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Biomedical subjects

J Dichgans

Publications and source records attributed to J Dichgans.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1989

On the role of feedback in maintaining constant grip force in patients with cerebellar disease.

The effect of visual feedback on maintaining low finger forces was investigated in patients with chronic cerebellar disease. Precise information about deviation from target force was compared with discrete feedback signaling only 3 states of performance and a condition of withdrawal of feedback. Forces were produced under isometric conditions and against a spring load (anisometric condition). Large performance differences were observed dependent on feedback condition. Maintenance of anisometric force was found to be nearly normal in patients with severe deficits in controlling isometric force.

Biofeedback, Psychology↗
PubMed1989

[Asymptomatic carotid stenosis: is surgical prevention of infarct still justified?].

The present retrospective study compared the incidence of TIA, stroke, and death in patients with asymptomatic carotid stenosis (greater than 50%) during a follow-up period of 24 to 30 months. 65 patients were operated and 193 treated medically. The incidence of death was comparable in both groups. Death in most patients was due to cardiac disease or cancer. The annual incidence of TIA and stroke was not different between the two populations. Despite the low incidence of perioperative complications (%) surgery of asymptomatic carotid stenosis cannot be recommended at the present time.

Aged↗
PubMed1989

Central effects of drugs used in migraine prophylaxis evaluated by visual evoked potentials.

The present study used recordings of visual potentials evoked by pattern reversal (VEPs) to investigate the central effects of three drugs used in migraine prophylaxis: the calcium channel blocker nifedipine, the beta-1-selective blocker metoprolol, and the nonselective beta adrenoreceptor blocker propranolol. The study involved 58 patients with common or classical migraine who were treated in a double-blind randomized study over a period of 7 months, while the effectiveness of prophylactic treatment was recorded in headache diaries that were subjected to time series analysis. VEPs were recorded at the beginning of a 2-month baseline period without treatment, after 4 months of treatment, and at the end of a 3-month washout period. At baseline, migraine patients had significantly higher VEP amplitudes and longer latencies than did a group of 87 healthy control subjects. Patients were separated by statistical analysis into responders and nonresponders to each prophylactic treatment. Nifedipine had no effects on the frequency, intensity, and duration of migraine attacks, nor on amplitude and latency of the VEPs. In contrast, the use of beta blockers resulted in a significant decrease in VEP amplitude, both in responders and nonresponders, whereas VEP latency remained unchanged. VEP amplitudes returned to the initial values at follow-up in the nonresponders, but stayed at lower levels in responders. Beta blockers thus appear to have a significant effect on the increased excitability of the visual system in patients with migraine, although their action is not directly related to their reduction of migraine frequency.

Adult↗
PubMed1989

Analgesic-induced chronic headache: long-term results of withdrawal therapy.

Headache characteristics are described in 139 patients with chronic daily or almost daily headaches due to regular intake of analgesics and the short- and long-term results of drug withdrawal. Drug-induced headache was described as dull, diffuse, and band-like, and usually started in the early morning. The mean duration of the original headache (migraine or tension headache) was 25 years; regular intake of drugs and chronic daily headache had started 10 and 6 years prior to withdrawal therapy, respectively. Patients took an average of 34.6 tablets or analgesic suppositories or antimigraine drugs per week containing 5.8 different substances. The drugs most often used were caffeine (95%), ergotalkaloids (89%), barbiturates (64%), and spasmolytics, paracetamol, and pyrazolone derivates (45%-46%). A total of 103 patients (68 migraine, 35 tension or combination headache) were available for interviews at a mean time interval of 2.9 years after an inpatient drug withdrawal programme. Chronic headache had disappeared or was reduced by more than 50% in two-thirds of the patients. Positive predictors for successful treatment were migraine as primary headache, chronic headache lasting less than 10 years, and regular intake of ergotamine. Drug intake was significantly reduced and patients used single substances more often. Patients who originally suffered from migraine, superimposed on the daily headache, also experienced a significant improvement in the frequency of the migraines and their intensity. Migraine prophylaxis through beta-blocking agents and calcium channel antagonists was more efficient after drug-withdrawal therapy.

Adult↗