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Biomedical subjects

A Curt

Publications and source records attributed to A Curt.

54 records · Page 3Linked to original sources
PubMed1998

Aspergillus spondylodiscitis in an immunocompetent paraplegic patient.

A case of an immunocompetent 60 year old patient is reported, who suffered extensive thoracic spinal injury and paraplegia after polytrauma. In the course of rehabilitation he developed aspergillus spondylodiscitis in a part of the thoraco-lumbar spine which was primarily uninjured. The diagnostic assessment and therapeutic approach of this rare disorder is elucidated and discussed in the context of paraplegia and polytrauma. Possible mechanisms of inoculation and spreading of the moulds as well as predisposing factors of the disease are discussed in this paper and a review of the recent literature is provided.

Aspergillosis↗
PubMed1998

How does the human brain deal with a spinal cord injury?

The primary sensorimotor cortex of the adult brain is capable of significant reorganization of topographic maps after deafferentation and de-efferentation. Here we show that patients with spinal cord injury exhibit extensive changes in the activation of cortical and subcortical brain areas during hand movements, irrespective of normal (paraplegic) or impaired (tetraplegic patients) hand function. Positron emission tomography ([15O]-H2O-PET) revealed not only an expansion of the cortical 'hand area' towards the cortical 'leg area', but also an enhanced bilateral activation of the thalamus and cerebellum. The areas of the brain which were activated were qualitatively the same in both paraplegic and tetraplegic patients, but differed quantitatively as a function of the level of their spinal cord injury. We postulate that the changes in brain activation following spinal cord injury may reflect an adaptation of hand movement to a new body reference scheme secondary to a reduced and altered spino-thalamic and spino-cerebellar input.

Adult↗
PubMed1997

Corticospinal input in human gait: modulation of magnetically evoked motor responses.

Transcranial magnetic stimulation (TMS) of the motor cortex was applied during locomotion to investigate the significance of corticospinal input upon the gait pattern. Evoked motor responses (EMR) were studied in the electromyogram (EMG) of tibialis anterior (TA), gastrocnemius (GM) and, for reference, abductor digiti minimi (AD) muscles by applying below-threshold magnetic stimuli during treadmill walking in healthy adults. Averages of 15 stimuli introduced randomly at each of 16 phases of the stride cycle were analysed. Phase-dependent amplitude modulation of EMR was present in TA and GM which did not always parallel the gait-associated modulation of the EMG activity. No variation of onset latency of the EMR was observed. The net modulatory response was calculated by comparing EMR amplitudes during gait with EMR amplitudes obtained (at corresponding background EMG activities) during tonic voluntary muscle contraction. Large net responses in both muscles occurred prior to or during phasic changes of EMG activity in the locomotor pattern. This facilitation of EMR was significantly higher in leg flexor than extensor muscles, with maxima in TA prior to and during late swing phase. A comparison of this facilitation of TA EMR prior to swing phase and prior to a phasic voluntary foot dorsiflexion revealed a similar onset but an increased amount of early facilitation in the gait condition. The modulated facilitation of EMR during locomotion could in part be explained by spinal effects which are different under dynamic and static motor conditions. However, we suggest that changes in corticospinal excitability during gait are also reflected in this facilitation. This suggestion is based on: (1) the similar onset yet dissimilar size of facilitatory effects in TA EMR prior to the swing phase of the stride cycle and during a voluntary dynamic activation, (2) the inverse variation of EMR and EMG amplitudes during this phase, and (3) the occurrence of this inversion at stimulation strengths below motor threshold (motor threshold was determined during weak tonic contraction and EMR were facilitated during gait). It is hypothesized that the facilitation is phase linked to ensure postural stability and is most effective during the phases prior to and during rhythmical activation of the leg muscles resulting in anticipatory adjustment of the locomotor pattern.

Adult↗
PubMed1997

[Prognosis of traumatic spinal cord lesions. Significance of clinical and electrophysiological findings].

The clinical examination of patients with spinal cord injury can be supplemented by electrophysiological techniques (somatosensory-evoked potentials (SSEP), motor-evoked potentials (MEP), electroneurography) to assess the extent and severity of a spinal cord injury. As essential advantage of these techniques in comparison with the clinical examination is that they can be reliably applied even in uncooperative patients. These techniques allow an early prognosis of the functional deficit in patients with acute spinal cord injury. Recordings of tibial nerve SSEP and MEP of the anterior tibial muscle allow to predict the outcome of ambulatory capacity, while recordings of pudendal nerve SSEP allow prognosis of the bladder function to be assessed. In tetraplegic patients median and ulnar nerve SSEP and MEP of the abductor digiti minimi muscle can indicate the development of hand function. Electroneurography allows to differentiate between the proportion of peripheral and central nervous lesions underlying the muscle paresis. This is of prognostic value with regard to the development of muscle tone and consequently for planning therapy. The electrophysiological examinations are of complementary value in the diagnostic assessment of spinal cord lesions, in the prediction of functional outcome, and in monitoring the course of neurological deficits. This is helpful for planning and selection of appropriate therapeutic approaches (e.g. functional electrical stimulation, application of botulinum toxin, splinting procedures) within the rehabilitation programme.

Activities of Daily Living↗
PubMed1997

Ambulatory capacity in spinal cord injury: significance of somatosensory evoked potentials and ASIA protocol in predicting outcome.

OBJECTIVE: Prediction of outcome of ambulatory capacity in patients with acute spinal cord injury (SCI) by the American Spinal Injury Association (ASIA) protocol and somatosensory evoked potentials (SSEP). DESIGN: Correlational study on a prospective cohort. SETTING: Spinal cord injury center, university hospital. PATIENTS: Consecutively sampled, 70 acute and 34 chronic SCI patients. MAIN OUTCOME MEASURES: (1) ASIA motor and sensory scores; (2) tibial and pudendal SSEP graded in 5 categories, from normal to absent; (3) ambulatory capacity rated as no, therapeutic, functional, or full. The outcome of the ambulatory capacity was assessed after discharge from the rehabilitation program, at least 6 months after trauma. RESULTS: In acute SCI both the initial ASIA scores and the SSEP recordings are related (p < .001) to the outcome of ambulatory capacity. In acute tetraplegia the pudendal SSEP (spearman corr. coeff. .92; p < .001) and in acute paraplegia the ASIA motor score (spearman corr. coeff. .90; p < .001) were best related to the outcome of ambulatory capacity. In the early stage of acute SCI, ASIA scores and SSEP recordings can help to assess the outcome of ambulatory capacity and, therefore, can contribute to the selection of the appropriate therapeutic approaches during the rehabilitation program. In patients with acute SCI the ASIA motor score significantly increased (p < .05) in the 6 months after trauma, whereas the ASIA sensory scores and SSEP recordings did not change significantly during this same period. CONCLUSION: ASIA scores and SSEP are related to the outcome of ambulatory capacity in patients with acute spinal cord injury; in noncomprehensive or uncooperative patients the SSEP are of supplemental value to the clinical examination. Therefore, the combination of clinical and electrophysiological examinations can be of additional diagnostic value in the assessment of acute spinal cord injury.

Adult↗
PubMed1997

Clinical value of F-wave recordings in traumatic cervical spinal cord injury.

F-waves and motor/sensory nerve conduction (NCS) of the median and ulnar nerves were examined in 66 patients with traumatic motoneurone lesion due to acute and chronic cervical spinal cord injury (SCI). The examinations were performed in parallel in chronic tetraplegics once and in acute tetraplegic patients monthly for the first 3 months, after 6 months and 1 year post-trauma. A pathological reduction of the compound muscle action potential (CMAP) (in 10% even a complete loss of the CMAP) was present in about 50% of the patients. The mean CMAP values of tetraplegic patients with either acute or chronic SCI were significantly (P < 0.001) reduced compared to normal subjects. Because sensory nerve conduction in these patients was normal, the reduction of CMAP should be due to damage of intramedullar motoneurones or anterior nerve roots. While in all chronic SCI patients with preserved CMAP F-waves could be elicited, 50% of the acute SCI patients showed a complete loss of F-waves of both nerves during the initial examination due to spinal shock. After 6 months all acute SCI patients with preserved motor potentials regained F-waves. Therefore, the excitability of F-waves is influenced by spinal shock in acute SCI. The mean F-wave latencies (Fmin-response, Fmin-M response) revealed no significant difference between healthy subjects and SCI patients. However, the frequency of F-wave production was related to the severity of the motoneurone lesion. Furthermore, while the F-wave latencies and CMAP values did not change significantly with time after acute SCI, the frequency of F-wave production increased, but remained reduced compared to normal subjects.

Action Potentials↗
PubMed1997

Recovery of bladder function in patients with acute spinal cord injury: significance of ASIA scores and somatosensory evoked potentials.

The significance of the ASIA (American Spinal Injury Association) scores and SSEP (somatosensory evoked potentials) recordings in predicting the recovery of bladder function was evaluated in 70 patients with acute, traumatic spinal cord injury (SCI). The patients were examined following admission to the rehabilitation centre (mean 10 days post-trauma) both clinically by the ASIA scores and electrophysiologically by tibial and pudendal SSEP recordings. The results of the initial examinations were related to the degree of recovery of bladder function of the patients assessed by urodynamic examination at the end of the rehabilitation programme (at least 6 months post-trauma). The recovery of somatic nerve function (external urethral sphincter function) involved in bladder function was correlated to both the initial ASIA scores and SSEP recordings (Spearman correlation, P < 0.001). The latter parameters, however, were not related to the outcome of autonomic nerve function (eg detrusor vesicae function) (Spearman correlation, P = 0.1). Therefore, the initial clinical and electrophysiological examinations are of value in assessment of the degree to which the patient will recover somatic nervous control of bladder function. However, these examinations are not indicative of urodynamic impairment. Therefore, urodynamic examination should be mandatory for the diagnostic assessment and therapeutical approach of bladder dysfunction in patients with acute SCI.

Adult↗
PubMed1997

Influence of spinal cord injury on cerebral sensorimotor systems: a PET study.

OBJECTIVES: To assess the effect of a transverse spinal cord lesion on cerebral energy metabolism in view of sensorimotor reorganisation. METHODS: PET and 18F-fluorodeoxyglucose were used to study resting cerebral glucose metabolism in 11 patients with complete paraplegia or tetraplegia after spinal cord injury and 12 healthy subjects. Regions of interest analysis was performed to determine global glucose metabolism (CMRGlu). Statistical parametric mapping was applied to compare both groups on a pixel by pixel basis (significance level P = 0.001). RESULTS: Global absolute CMRGlu was lower in spinal cord injury (33.6 (6.6) mumol/100 ml/min (mean (SD)) than in controls (45.6 (6.2), Mann-Whitney P = 0.0026). Statistical parametric mapping analysis disclosed relatively increased glucose metabolism particularly in the supplementary motor area, anterior cingulate, and putamen. Relatively reduced glucose metabolism in patients with spinal cord injury was found in the midbrain, cerebellar hemispheres, and temporal cortex. CONCLUSIONS: It is assumed that cerebral deafferentiation due to reduction or loss of sensorimotor function results in the low level of absolute global CMRGlu found in patients with spinal cord injury. Relatively increased glucose metabolism in brain regions involved in attention and initiation of movement may be related to secondary disinhibition of these regions.

Adult↗
PubMed1997

Assessment of autonomic dysreflexia in patients with spinal cord injury.

OBJECTIVES AND METHODS: To assess the impairment of supraspinal control over spinal sympathetic centres and the occurrence of autonomic dysreflexia in patients with spinal cord injury. Autonomic dysreflexia is caused by the disconnection of spinal sympathetic centres from supraspinal control and is characterised by paroxysmal hypertensive episodes caused by non-specific stimuli below the level of the lesion. Therefore, patients with spinal cord injury were examined clinically and by different techniques to assess the occurrence of autonomic dysreflexia and to relate disturbances of the sympathetic nervous system to episodes of autonomic dysreflexia. RESULTS: None of the paraplegic patients, but 59% (13/22) of tetraplegic patients (91% of the complete, 27% of the incomplete patients) presented signs of autonomic dysreflexia during urodynamic examination. Only 62% of the tetraplegic patients complained about symptoms of autonomic dysreflexia. Pathological sympathetic skin responses (SSRs) of the hands were related to signs of autonomic dysreflexia in 93% of cases. No patient with preserved SSR potentials of the hands and feet showed signs of autonomic dysreflexia, either clinically or during urodynamic examination. Ambulatory blood pressure measurements (ABPMs) indicated a loss of circadian blood pressure rhythm (sympathetic control) but preserved heart rate rhythm (parasympathetic regulation) only in patients with complete tetraplegia. Pathological ABPM recordings were seen in 70% of patients with symptoms of autonomic dysreflexia. CONCLUSIONS: The urodynamic examination was more sensitive in indicating signs of autonomic dysreflexia in patients with spinal cord injury, whereas SSR allowed the assessment of the degree of disconnection of the sympathetic spinal centres from supraspinal control. Using ABPM recordings the occurrence of episodes of autonomic dysreflexia over 24 hours and the effectiveness of therapeutical treatment can be assessed.

Adolescent↗
PubMed1997

The value of sympathetic skin response recordings in the assessment of the vesicourethral autonomic nervous dysfunction in spinal cord injured patients.

PURPOSE: We assessed the degree of sparing of the descending sympathetic spinal tract and correlated these findings with bladder neck function in spinal cord injured patients. MATERIALS AND METHODS: Sympathetic skin responses of the right hand and foot were recorded and compared to the urodynamic findings in 27 spinal cord injured patients. RESULTS: All tetraplegic and paraplegic patients with a lesion above the T6 level who presented with bladder neck dyssynergia associated with autonomic hyperreflexia had abnormal sympathetic skin responses in the right hand and foot. All patients with a lesion below the T6 and above the T12 levels with an abnormal sympathetic skin response in the right foot also had bladder neck dyssynergia. CONCLUSIONS: Evidence is presented that the integrity of the descending sympathetic spinal tract is necessary for a synergic function of the vesicourethral complex and that sympathetic skin responses are of value in the diagnosis of bladder neck dyssynergia. For lesions below the T12 level other investigative methods to exclude bladder neck dyssynergia are necessary.

Autonomic Nervous System↗
PubMed1996

Significance of sympathetic skin response in the assessment of autonomic failure in patients with spinal cord injury.

As a result of spinal cord injury (SCI) descending spinal sympathetic pathways can be severed. Because of its clinical significance, the aim of this study was to assess the disturbance of the spinal sympathetic pathway by clinical and electrophysiological examinations. The sympathetic skin response (SSR) due to electrical stimulation of median nerve and transcranial magnetic stimulation was examined in 70 patients with complete and incomplete spinal cord injury. Clinical and neurological examinations were performed in these patients according to the protocol of the American Spinal Injury Association (ASIA). The SSR can be used to assess the integrity of the spinal sympathetic nervous system. In patients with complete tetraplegia and paraplegics with high thoracical lesions (up to level T3) SSRs of the hands and feet were absent. In patients with complete paraplegia and thoroacic lesions from level T4 up to T8 the SSRs could be evoked in the hands but not in the feet. However, in paraplegics with lumbal and thoracic lesions below level T8 SSRs of the hands and feet could be recorded. In about 50% of the patients with clinically incomplete SCI lesions SSR potentials were abolished, indicating that the spinal sympathetic system was severely affected. There was no patient with preserved SSR potentials who developed symptoms of autonomic dysreflexia (AD). However, all patients with episodes of AD showed abolished SSR at the hands and feet even in incomplete SCI patients. The results of the SSR recordings in SCI patients fit with the assumption that the development of AD is related to the disconnection of the spinal sympathetic centers from supraspinal control.

Adult↗
PubMed1996

Traumatic cervical spinal cord injury: relation between somatosensory evoked potentials, neurological deficit, and hand function.

OBJECTIVE: Median and ulnar somatosensory evoked potentials (SEP) in the assessment of cervical spinal cord injury (SCI) in relation to the outcome of hand function. DESIGN: Cohort analytical study. SETTING: Spinal cord injury center, university hospital. PATIENTS: Consecutively sampled, 23 acute and 46 chronic tetraplegics. MAIN OUTCOME MEASURES: (1) Median and ulnar SEP recordings graded in 5 categories, from normal to absent; (2) clinical examination of algesia/aesthesia in dermatomes C5/6 and C8/Th1 graded in categories of normal, impaired, and loss of sensation; (3) clinical examination of hand function graded in 4 categories, from active to inactive hand function. RESULTS: Pathological median and ulnar SEP were found in 46% and 76% of patients, respectively. A differentiation between upper (C3-C6) and lower (C6/C7-Th1) cervical SCI was possible by comparing the SEP N20 latencies (but not amplitudes) of both nerves (Mann-Whitney U test, p < .01). In follow-up examinations over 6 months the N20 amplitude increased significantly (ANCOVA, p < .001), while the N20 latency did not change. By both ulnar SEP recordings and assessment of the sensory deficit in dermatome C8/Th1 the outcome of hand function, i.e., the development of active or inactive hand function, could be predicted (Mann-Whitney U test, p < .01). CONCLUSION: Median and ulnar SEP are valuable to indicate the level of injury, the degree of sensory impairment and to predict the outcome of hand function even in unconscious patients. They can improve the diagnostic assessment of cervical SCI.

Adolescent↗
PubMed1996

Botulinum-A toxin as a treatment of detrusor-sphincter dyssynergia: a prospective study in 24 spinal cord injury patients.

PURPOSE: The paralytic effect of botulinum-A toxin injections on the external urethral sphincter was investigated prospectively in patients with neurogenic voiding disorders. MATERIALS AND METHODS: Transurethral versus transperineal botulinum-A toxin injections were performed in 24 spinal cord injury male patients with detrusor-sphincter dyssynergia and the respective efficacy was compared. RESULTS: In 21 of 24 patients detrusor-sphincter dyssynergia was significantly improved with a concomitant decrease in post-void residual volumes in most cases. Botulinum-A toxin effects lasted 3 to 9 months, making reinjections necessary. CONCLUSIONS: Although costly, botulinum-A toxin injections, which aim at suppressing detrusor-sphincter dyssynergia but not bladder neck dyssynergia, appear to be a valid alternative for patients who do not desire surgery or are unable to perform self-catheterization.

Adolescent↗
PubMed1996

Neurographic assessment of intramedullary motoneurone lesions in cervical spinal cord injury: consequences for hand function.

Examination of hand function and neurography of the median- and ulnar nerves was performed in 15 patients with acute and 26 patients with chronic tetraplegia due to cervical spinal cord injury (SCI). 30% of patients showed a mild and 20% a severe axonal lesion of motor fibres of both nerves. The latter is caused by intramedullary damage of ventral horn cells and anterior nerve roots as neurographic examination of sensory nerve fibres was normal in these patients. The most frequent and severe nerve lesion was present in those with lower cervical spinal cord injuries (C6/7-Th1) where the median and ulnar nerves originate. In the latter patients the development of active hand function, which enables the patient to perform active grasping movements, was closely related to the result of neurography, already early after trauma. The results of median and ulnar neurography in tetraplegia due to cervical SCI allow to differentiate between intramedullary damage of motoneurones and the anterior nerve roots (peripheral nervous system) or the pyramidal tract fibres (central nervous system) within the spinal cord responsible for the paresis of the intrinsic hand muscles. Neurography is of prognostic value in cervical SCI to predict the outcome of hand function and therefore influences the appropriate occupational therapy and the program and aims of rehabilitation.

Action Potentials↗
PubMed1996

Loss of circadian blood pressure variability in complete tetraplegia.

Blood pressure (BP) and heart rate (HR) were monitored over 24 h utilising an ambulatory blood pressure monitoring (ABPM) system in 33 subjects with spinal cord injury: 11 patients with complete tetraplegia, 13 patients with incomplete tetraplegia and nine patients with complete paraplegia. Measurements were analysed for overall levels of BP and HR, presence of a physiological day/night cycle and events of autonomic dysreflexia. Paraplegic patients exhibited normal BP and HR levels with a physiological circadian rhythm. In complete tetraplegic patients the circadian rhythm was abolished for BP but preserved for HR, while in patients with incomplete tetraplegia circadian rhythm was preserved for both BP and HR. Complete tetraplegic patients with autonomic dysreflexia revealed a typical pattern in ABPM with multiple hypertensive episodes and concomitant bradycardia. Under adequate treatment these episodes could be reduced or abolished, while the disturbed circadian BP rhythm persisted. These observations shed further light on mechanisms of central BP and HR control. In tetraplegic patients ABPM is an efficient method to assess treatment for autonomic dysreflexia.

Adolescent↗
PubMed1986

The effect of experimental carcinogenesis on intestinal diamine oxidase, a polyamine deaminating enzyme.

Intestinal mucosa hyperproliferation is an important risk factor of large bowel carcinoma development. Intestinal diamine oxidase (DAO) is suggested to be a proliferation terminating principle in the mature mucosa. Therefore, the influence of the carcinogen azoxymethane (AOM) on this enzyme was studied. The enzyme was measured with the 14C-putrescine assay. In vitro the enzyme was inhibited only by excessive high concentrations of AOM (89 mmol/liter). In vivo the enzymic activity was reduced in the duodenum but not in the colon during the first 48 hr after AOM application (15 mg/kg). Ten weekly injections of AOM reduced the DAO activity in the duodenum and colon significantly (alpha = 0.05). After the stop of the AOM application a significant (alpha = 0.05) increase of DAO activity over the control level was found which was interpreted as a defense reaction of the mucosa against the hyperproliferation that had occurred during the carcinogen treatment. Intestinal DAO is regarded as an antiproliferative principle protecting the integrity of the intestinal mucosa. An inhibition of this enzyme probably increases the risk of intestinal carcinoma promotion.

Amine Oxidase (Copper-Containing)↗