PubMed Health⌕ Search

Biomedical subjects

J T Tans

Publications and source records attributed to J T Tans.

At least 19 recordsLinked to original sources
PubMed2001

[Hemicraniectomy for treatment of malignant medial cerebral artery infarction in 3 patients].

In three patients, a 52-year old man, a 54-year old man and a 17-year old woman, sudden neurological signs such as hemiparalysis and hemihypaesthesia developed, with diminished consciousness occurring at a later stage. Imaging revealed total infarction of the area supplied by the right middle cerebral artery with the threat of intracranial hypertension. Once informed consent had been obtained from the patient's representatives, hemicraniectomy with dural augmentation was performed. Although the primary neurological deficit persisted, the three patients assessed their quality of life as valuable with their Barthel scores ranging from 45 to 90. Total infarction of the middle cerebral artery may result in intracranial hypertension and transtentorial herniation owing to the development of cytotoxic oedema, particularly in young patients. The prognosis of this condition is poor partly due to the limited effect of non-surgical treatment. Hemicraniectomy with dural augmentation prevents secondary brain damage caused by the space-occupying effect of the infarct. This operation reduces mortality considerably. The findings in these patients along with the results in the literature warrant a randomised study of the results of hemicraniectomy in patients with malignant middle cerebral artery infarction.

Adolescent↗
PubMed2000

The Dutch normal-pressure hydrocephalus study. How to select patients for shunting? An analysis of four diagnostic criteria.

BACKGROUND: Comparison of the predictive value of four "diagnostic tests" for the outcome of shunting in patients with normal-pressure hydrocephalus (NPH). METHODS: Ninety-five NPH patients who received shunts were followed for 1 year. Gait disturbance and dementia were quantified by an NPH scale and handicap by a modified Rankin scale. Primary outcome measures were differences between the preoperative and last scores on both the NPH scale and the modified Rankin scale. Clinical and computed tomographic (CT) findings typical of NPH, absence of cerebrovascular disease, and a resistance to outflow of cerebrospinal fluid (CSF) >/= 18 mmHg/ml/minute were designated as a positive test outcome; clinical and CT findings compatible with NPH, presence of cerebrovascular disease, and an outflow resistance < 18 mmHg/ml/minute as a negative test outcome. RESULTS: For each of the four tests the percentage of patients classified as improved was significantly greater for those with positive than with negative test results. Measurement of CSF outflow resistance was the only significant prognostic factor for the improvement ratio in NPH scale and CT in the modified Rankin scale according to multivariate logistic regression analysis. The accurate predictive value of the combination of typical clinical and CT findings was 0.65, that of the positive test results of outflow resistance, clinical and CT findings was 0.74. CONCLUSION: The best strategy is to shunt NPH patients if their outflow resistance is >/= 18 mmHg/ml/minute or, when the outflow resistance is lower, if their clinical as well as their CT findings are typical of NPH.

Adult↗
PubMed1999

[Intracranial arteriovenous malformations in pregnant women].

Three women, aged 27, 32 and 30 years, respectively, suffered from headache, nausea and neurological abnormalities and were found to have an intracranial arteriovenous malformation (AVM). One of them after diagnosis had two pregnancies, both ended by caesarean section with good results. Another woman was 32 weeks pregnant when the AVM manifested itself with a haemorrhage; she recovered well and was delivered by caesarean section. After the AVM proved radiologically to have been obliterated, she delivered after her subsequent pregnancy by the vaginal route with vacuum extraction. The third woman was 15 weeks pregnant when major abnormalities developed. There was a large intracerebral haematoma with break-through to the ventricular system; this patient died. Intracranial haemorrhage during pregnancy is rate. It can result in maternal and foetal morbidity and mortality. It appears that pregnancy does not increase the rate of first cerebral haemorrhage from an AVM. The management of AVM rupture during pregnancy should be based primarily on neurosurgical rather than on obstetric considerations. Close collaboration with a team of neurologists, neurosurgeons, obstetricians and anaesthesiologists is mandatory.

Adult↗
PubMed1999

Dutch Normal-Pressure Hydrocephalus Study: the role of cerebrovascular disease.

OBJECT: This study was conducted to determine the prevalence of cerebrovascular disease and its risk factors among patients with normal-pressure hydrocephalus (NPH) and to assess the influence of these factors on the outcome of shunt placement. METHODS: A cohort of 101 patients with NPH underwent shunt placement and was followed for 1 year. Gait disturbance and dementia were quantified using an NPH scale and handicap was determined using a modified Rankin scale (mRS). Primary outcome measures consisted of the differences between preoperative and last NPH scale and mRS scores. The presence of risk factors such as hypertension, diabetes mellitus, cardiac disease, peripheral vascular disease, male gender, and advancing age was recorded. Cerebrovascular disease was defined as a history of stroke or a computerized tomography (CT) scan revealing infarcts or moderate-to-severe white matter hypodense lesions. The prevalence of risk factors for cerebrovascular disease was higher in the 45 patients with cerebrovascular disease than the 56 without it. Risk factors did not influence outcome after shunt placement. Intent-to-treat analysis revealed that the mean improvement in the various scales was significantly less for patients with a history of stroke (14 patients), CT scans revealing infarctions (13), or white matter hypodense lesions (32 patients) than for those without cerebrovascular disease. The proportion of patients who responded to shunt placement was also significantly lower among patients with than those without cerebrovascular disease (p=0.02). CONCLUSIONS: The authors identified a subgroup of patients with NPH and cerebrovascular disease who showed disappointing results after shunt placement. Cerebrovascular disease was an important predictor of poor outcome.

Aged↗
PubMed1998

Does CSF outflow resistance predict the response to shunting in patients with normal pressure hydrocephalus?

The value of the measurements of CSF outflow resistance (Rcsf) relative to predicting outcome after shunting was studied. In a group of 101 patients with mainly idiopathic normal pressure hydrocephalus (NPH) Rcsf was obtained by lumbar constant flow infusion. Gait disturbance and dementia were quantified using an NPH scale (NPHS) and disability by the Modified Rankin scale (MRS). Patients were assessed before and at 1, 3, 6, 9 and 12 months after surgery. Outcome measures were differences between the preoperative and last NPHS and MRS scores. Improvement was defined as a change of > or = 15% in NPHS and > or = 1 grade in MRS. Intention-to-treat analysis of all patients at one year yielded improvement of 57% in NPHS and 59% in MRS. Efficacy analysis, excluding comorbidity unrelated to NPH, revealed positive predictive values of around 80% at Rcsf < 18, and between 90% and 100% at Rcsf > or = 18 mm Hg/ml/min. For Rcsf > or = 18, the likelihood ratios were also higher. We conclude that the best predictor of the response to shunting is an Rcsf > or = 18 mm Hg/ml/min. Since two-thirds of the patients with Rcsf < 18 showed improvement as well, these patients should not be denied shunting.

Cerebrospinal Fluid Pressure↗
PubMed1998

Dutch Normal-Pressure Hydrocephalus Study: randomized comparison of low- and medium-pressure shunts.

OBJECT: The goal of this prospective study was to compare outcome after placement of a low- or medium-pressure shunt in patients with normal-pressure hydrocephalus (NPH). METHODS: Ninety-six patients with NPH were randomized to receive a low-pressure ventriculoperitoneal shunt (LPV; 40 +/- 10 mm H2O) or medium high-pressure ventriculoperitoneal shunt (MPV; 100 +/- 10 mm H2O). The patients' gait disturbance and dementia were quantified by applying an NPH scale, and their level of disability was evaluated by using the modified Rankin scale (mRS). Patients were examined prior to and 1, 3, 6, 9, and 12 months after surgery. Primary outcome measures were determined by differences between preoperative and last NPH scale scores and mRS grades. The LPV and MPV shunt groups were compared by calculating both the differences between mean improvements and the proportions of patients showing improvement. Intention-to-treat analysis of mRS grades yielded a mean improvement of 1.27 +/- 1.41 for patients with LPV shunts and 0.68 +/- 1.58 for patients with MPV shunts (p = 0.06). Improvement was found in 74% of patients with LPV shunts and in 53% of patients with MPV shunts (p = 0.06) and a marked-to-excellent improvement in 45% of patients with LPV shunts and 28% of patients with MPV shunts (p = 0.12). All outcome measures indicated trends in favor of the LPV shunt group, with only the dementia scale reaching significance. After exclusion of serious events and deaths unrelated to NPH, efficacy analysis showed the advantage of LPV shunts to be diminished. Reduction in ventricular size was also significantly greater for patients in the LPV shunt group (p = 0.009). Subdural effusions occurred in 71% of patients with an LPV shunt and in 34% with an MPV shunt; however, their influence on patient outcome was limited. CONCLUSIONS: Outcome was better for patients who had an LPV shunt than for those with an MPV shunt, although most differences were not statistically significant. The authors advise that patients with NPH be treated with an LPV shunt.

Aged↗
PubMed1997

Dutch normal-pressure hydrocephalus study: prediction of outcome after shunting by resistance to outflow of cerebrospinal fluid.

The authors examined whether measurement of resistance to outflow of cerebrospinal fluid (Rcsf) predicts outcome after shunting for patients with normal-pressure hydrocephalus (NPH). In four centers 101 patients (most of whom had idiopathic NPH) who fulfilled strict entry criteria underwent shunt placement irrespective of their level of Rcsf obtained by lumbar constant flow infusion. Gait disturbance and dementia were quantified by using an NPH scale and the patient's level of disability was assessed by using the modified Rankin scale (mRS). In addition the Modified Mini-Mental State Examination was performed. Patients were assessed prior to and 1, 3, 6, 9, and 12 months after surgery. Primary outcome measures were based on differences between the preoperative and last NPH scale scores and mRS grades. Improvement was defined as a change measuring at least 15% in the NPH scale score and at least one mRS grade. Intention-to-treat analysis of all patients at 1 year yielded improvement for 57% in NPH scale score and 59% in mRS grade. Efficacy analysis, excluding serious events and deaths that were unrelated to NPH, was performed for 95 patients. Improvement rose to 76% in NPH scale score and 69% in mRS grade. Six cut-off levels of Rcsf were related to improvement in NPH scale score using two-by-two tables. Positive predictive values were approximately 80% for an Rcsf of 10, 12, or 15 mm Hg/ml/minute, 92% for an Rcsf of 18 mm Hg/ml/minute, and 100% for an Rcsf of 24 mm Hg/ml/minute. Negative predictive values were low. More important was the highest likelihood ratio of 3.5 for an Rcsf of 18 mm Hg/ml/minute. Extensive comorbidity was a major prognostic factor. Measurement of Rcsf reliably predicts outcome if the limit for shunting is raised to 18 mm Hg/ml/minute. At lower Rcsf values the decision depends mainly on the extent to which clinical and computerized tomography findings are typical of NPH.

Aged↗
PubMed1994

The choice of treatment of single brain metastasis should be based on extracranial tumor activity and age.

PURPOSE: To determine if in patients with single brain metastasis the addition of neurosurgery to radiotherapy leads to lengthening of survival or to better quality of life. METHODS AND MATERIALS: From 1985 to 1990, 66 patients with single brain metastasis from a solid tumor were entered in a randomized trial of neurosurgery plus radiotherapy vs. radiotherapy alone. Patients were stratified for lung cancer vs. other sites of cancer and for progressive vs. stable systemic cancer. Radiotherapy was given to the whole brain by a novel scheme of two fractions of 2 Gy per day for a total dose of 40 Gy in 2 weeks, to obtain a relatively high total dose and short overall time, with minimal risk of late damage to normal tissue in long-term survivors. RESULTS: In the whole group of 63 evaluable patients, both with lung cancer as with other tumors, the combined treatment led to a better duration of survival (median 10 vs. 6 months; p = 0.04). The largest difference between both treatment arms was observed in patients with inactive extracranial disease (median 12 vs. 7 months; p = 0.02). Patients with active extracranial disease had an equal median survival of only 5 months, irrespective of given treatment. Age proved to be a strong and independent prognostic factor: patients older than 60 years had a hazard ratio of dying of 2.74 (p = 0.003) compared with younger patients. Following treatment, most patients remained functionally independent until a few weeks before death. In the majority of patients the cause of death was systemic tumor progression. CONCLUSION: Patients with single brain metastasis and with controlled or absent extracranial tumor activity should be treated with surgery and radiotherapy, especially when they are younger than 60 years. For patients with progressive extracranial disease, radiotherapy alone seems to be sufficient. The accelerated radiotherapy scheme of 40 Gy in 2 weeks to the whole brain is tolerated well and should also be considered for patients in a good performance status with surgically unaccessible single metastasis or even with multiple brain metastases.

Adult↗
PubMed1993

Treatment of single brain metastasis: radiotherapy alone or combined with neurosurgery?

Most patients treated for single or multiple brain metastases die from progression of extracranial tumor activity. This makes it uncertain whether the combination of neurosurgery and radiotherapy for treatment of single brain metastasis will lead to better results than less invasive treatment with radiotherapy alone. The effect of neurosurgical excision plus radiotherapy was compared with radiotherapy alone in a prospectively randomized trial with 63 evaluable patients with systemic cancer and a radiological diagnosis of single brain metastasis. Radiotherapy was given to the whole brain by a novel scheme of 2 fractions per day of each 2 Gy for a total of 40 Gy. Before randomization, patients were stratified by site (lung cancer vs nonlung cancer) and status of extracranial disease (progressive vs stable). Survival as such and functionally independent survival (FIS; defined as World Health Organization performance status < or = 1 and neurological function < or = 1) were compared between both treatment arms. The combined treatment compared with radiotherapy alone led to a longer survival (p = 0.04) and a longer FIS (p = 0.06). This was most pronounced in patients with stable extracranial disease (median survival, 12 vs 7 mo; median FIS, 9 vs 4 mo). Patients with progressive extracranial cancer had a median overall survival of 5 months and a FIS of 2.5 months irrespective of given treatment. Improvement in functional status occurred more rapidly and for longer periods of time after neurosurgical excision and radiotherapy than after radiotherapy alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Acute hydrocephalus in nonaneurysmal perimesencephalic hemorrhage: evidence of CSF block at the tentorial hiatus.

The acute hydrocephalus in patients with nonaneurysmal perimesencephalic hemorrhage suggests an extraventricular obstruction of CSF flow. We studied the occurrence of acute hydrocephalus and the site of cisternal blood in 40 consecutive patients with perimesencephalic hemorrhage. In all 11 patients with hydrocephalus, all perimesencephalic cisterns were filled with blood; this occurred in only five of the 29 patients (17%) without hydrocephalus (p less than 0.0001). We conclude that in the absence of intraventricular blood, filling of all perimesencephalic cisterns with blood is a necessary factor for the development of acute hydrocephalus.

Acute Disease↗
PubMed1990

Outcome in perimesencephalic (nonaneurysmal) subarachnoid hemorrhage: a follow-up study in 37 patients.

We interviewed 37 patients with perimesencephalic hemorrhage, 18 months to 7 years after the bleed. None rebled or had persisting neurologic deficits. These findings are remarkably good compared with recent series of patients with subarachnoid hemorrhage and normal angiogram. When blood is confined to the mesencephalic cisterns in patients with normal angiogram, repeat angiography may not be indicated.

Adult↗
PubMed1989

Does compliance predict ventricular reduction after shunting for normal pressure hydrocephalus.

Ventricular reduction after shunting for normal pressure hydrocephalus (NPH) was classified on the basis of magnitude and rate of reduction in 35 adult patients. Brain compliance and resistance to outflow of cerebrospinal fluid (RCSF) were determined before shunting. Rapid and marked ventricular reduction (n = 11) was associated with a significantly lower compliance than slow and moderate to marked (n = 16) or minimal to mild (n = 8) reduction. Otherwise ventricular size before as well as after shunting did not correlate with compliance or RCSF. It is concluded that both rate and magnitude of ventricular reduction after shunting for NPH vary widely. Reduced compliance seems to be the best predictor of rapid and marked reduction.

Adult↗
PubMed1989

Relationship between compliance and resistance to outflow of CSF in adult hydrocephalus.

Resistance to outflow of cerebrospinal fluid (Rcsf) was determined by constant flow infusions and pressure-volume index (PVI) using bolus infusions in 114 patients with various types of hydrocephalus. A clear correlation was found between PVI and Rcsf and, to a lesser degree, between these two parameters and baseline pressure. The PVI was not related to patient's age, duration of disease, type of hydrocephalus, or ventricular size, indicating that the relationship between PVI and Rcsf was genuine and not caused by patient selection. It is concluded that, in adult hydrocephalus, compliance is not an independent parameter but chiefly determined by Rcsf.

Adolescent↗
PubMed1988

Reduction of ventricular size after shunting for normal pressure hydrocephalus related to CSF dynamics before shunting.

Reduction of ventricular size was determined by repeated computed tomography in 30 adult patients shunted for normal pressure hydrocephalus (NPH) and related to the pressure-volume index (PVI) and resistance to outflow of cerebrospinal fluid (Rcsf) measured before shunting. Rapid and marked reduction of ventricular size (n = 10) was associated with a significantly lower PVI than slow and moderate to marked (n = 13) or minimal to mild reduction (n = 7). Otherwise no relationship could be found between the reduction of ventricular size and PVI or Rcsf. It is concluded that both rate and magnitude of reduction of ventricular size after shunting for NPH are extremely variable. High brain elasticity seems to be the best predictor of rapid and marked reduction.

Adult↗
PubMed1986

The effect of reconstructive vascular surgery on clinical status, quantitative EEG and cerebral blood flow in patients with cerebral ischaemia. A three month follow-up study in operated and unoperated stroke patients.

Follow-up studies over a period of 3 months were carried out on 100 patients with a unilateral ischaemia in the territory of the middle cerebral artery. Twenty-six patients underwent an STA-MCA bypass operation and 23 patients, a carotid endarterectomy. Fifty-one unoperated patients served as a reference group. A clinical examination, quantitative electroencephalogram (qEEG) and cerebral blood flow study (CBF) were performed before, 2 weeks after and 3 months after surgery. In the unoperated patients these examinations were carried out shortly after admission, 3 weeks later and 3 months thereafter. In the unoperated group, a highly significant improvement of clinical score and qEEG was found, but there were no changes in CBF values. The bypass patients showed a transient deterioration of clinical score and qEEG after surgery. Further, over the 3 month post-operative period, the bypass patients and the endarterectomy patients showed no improvement in CBF and qEEG. Thus, a beneficial effect of reconstructive surgery over the period studied could not be demonstrated.

Brain↗
PubMed1986

Diastematomyelia presenting in two male adults with low back pain.

Two cases of diastematomyelia with adult onset are added to the 19 patients already reported in the literature. Seventeen of them exhibited a neurological deficit, whereas our patients presented with low back pain only. Cutaneous, neuromuscular and/or radiological signs of spinal dysraphysm were found in all patients with adult diastematomyelia. If the presence of these signs were to receive more attention, more cases of adult diastematomyelia would be recognized.

Adult↗