Spinocerebellar ataxia type 2. Genotype and phenotype in German kindreds

BACKGROUND

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant cerebellar ataxia (ADCA) for which the disease-causing mutation has recently been characterized as an expanded CAG trinucleotide repeat. We investigated 64 families of German ancestry with ADCA and 55 patients with sporadic ataxia for the SCA2 mutation.

RESULTS

Expanded alleles were found in 6 of the 64 families and in 1 patient with sporadic ataxia. This patient had a de novo mutation from an intermediate paternal allele. Length of repeats in 21 patients with SCA2 ranged from 36 to 52 CAG motifs and was inversely correlated with age at onset and progression of the disease. Expanded alleles were unstable during meiosis; paternal transmission especially caused significant anticipation of onset up to 26 years earlier. The SCA2 phenotype differed from those of SCA1 and SCA3 with higher frequencies of slowed ocular movements, postural and action tremor, myoclonus, and hyporeflexia. However, no single feature was sufficient to permit a specific clinical diagnosis.

CONCLUSIONS

Spinocerebellar ataxia type 2 accounts for about 10% of German families with ADCA but may also be present in sporadic ataxia due to de novo mutations. Clinical features are highly variable among and even within families. However, the size of the expanded repeat influences the phenotype and is relevant for course and prognosis of the disease.

Failure after osteosynthesis of trochanteric fractures. Where is the limit of osteoporosis?

SUMMARY

The aim of this study is to identify osteoporosis values, beyond which there is a high risk of osteosynthesis failure. Bone mineral density (BMD) of 30 cadaveric femora with a pertrochanteric fracture osteotomy was correlated to the risk of cut out after osteosynthesis on a biomechanical testing approach. For a BMD less than 250 mg/cm(3), there is a high risk of fixation failure after surgical treatment of pertrochanteric fractures. This value can be regarded as a reference value for future experimental and clinical studies.

INTRODUCTION

Despite continuous modification of intramedullary load carriers for the surgical stabilization of trochanteric fractures, cut out remains the most frequent complication. The aim of this experimental study was to identify threshold osteoporosis values, beyond which there is a high risk of osteosynthesis failure.

METHODS

Bone mineral density (BMD) of 30 cadaveric femora was recorded for the femoral head by QCT measurement. Subsequently, a standardized osteotomy mimicking an unstable trochanteric type fracture was stabilized by intramedullary nailing. The constructs were loaded axially at a force of 2,100 N up to 20,000 cycles. Cut out at the femoral head was documented by radiograph. Statistical evaluation of the cohort group was performed by calculation of relative risk in relation to the BMD values.

RESULTS

In total, there were six cases of cut out after 10,000 cycles. The incidence of cut out for BMD less than 250 mg/cm(3) was 0.55 (5 of 9) and for BMD greater than 250 mg/cm(3), it was 0.05 (1 of 21). Therefore, the relative risk of cut out for BMD <250 mg/cm(3) is 11× greater than for a BMD >250 mg/cm(3). After 20,000 cycles, an additional test caused one cut out (relative risk of cut out for a BMD <250 mg/cm(3) 5.8).

CONCLUSIONS

For a BMD less than 250 mg/cm(3), there is a high risk of fixation failure after surgical treatment of pertrochanteric fractures. Although this value is based on an experimental in vitro study design with all its associated limitations, it can be regarded as a reference value for future experimental and clinical studies.

Bilateral contrast-enhanced MR angiography of the hand: diagnostic image quality of accelerated MRI using echo sharing with interleaved stochastic trajectories (TWIST)

OBJECTIVES

To evaluate the image quality of time-resolved contrast-enhanced MRA (tr-MRA) employing echo-sharing with stochastic trajectories for the bilateral examination of the hands.

METHODS

In this institutional review-board approved study, Tr-MRA was compared with multiphasic contrast-enhanced MRA (mp-MRA) featuring sub-systolic venous compression in 20 healthy volunteers at 3.0 T using the following settings: TR/TE: 2.8/1.2 ms, flip angle: 25°, acceleration factor: 4, effective voxel size: 0.9 × 0.8 × 0.9 cm, acquisition time 4.9 s per 3D volume.

RESULTS

With tr-MRA the arterial first-pass contrast agent transit is clearly seen. On average the contrast agent arrived 34 s post-injection and reached the proper digital arteries after 44 s. The mean arterio-venous window was 13 s. Bilateral contrast enhancement was asynchronous in 56-62%. On a semiquantitative scale (0 = non-sufficient to 4 = excellent) tr-MRA (mp-MRA) yielded an average ranking of 2.8-3.6 (3.1-3.8) in the greater and intermediate sized segments and 1.3-2.0 (1.6-2.3) in the proper digital arteries.

CONCLUSION

Compared with established multiphasic ce-MRA, time-resolved MRA allows a four times faster acquisition. It reflects the natural haemodynamics of the hand arteries with no need for sub-systolic venous compression and may be beneficial in the detection of hand circulation disorders. Image quality is comparable to mp-MRA. In both techniques depiction of the proper digital arteries is limited.

Treatment of hypertensive emergency. Comparison of a new dosage form of the calcium antagonist nitrendipine with nifedipine capsules

OBJECTIVE

To present the efficacy and tolerability of a new oral dosage form of the calcium antagonist nitrendipine compared to nifedipine capsules in patients with hypertensive emergency.

DESIGN

Multicenter randomized double blind clinical study.

SETTING

23 study centres (hospitals) in Germany.

PATIENTS

161 patients between 20 and 70 years with acutely elevated blood pressure (systolic 200-250 mmHg, diastolic between 110-140 mmHg) with and without concomitant clinical symptoms.

INTERVENTIONS

Double blind treatment with 10 mg nifedipine or 5 mg nitrendipine. Nifedipine was administered as capsules, nitrendipine was given from a small plastic tube (vial), containing 1 ml alcoholic solution. Every patient received in addition to the test medication a placebo corresponding to the other product. Patients with insufficient treatment after 45 min were given either an additional capsule of 10 mg nifedipine or a further vial containing 5 mg nitrendipine according to their group and maintaining the double dummy procedure.

MEASUREMENTS AND RESULTS

Blood pressure and heart rate were measured repeatedly during 4 h, before and 90 min after beginning of the treatment a 12 channel resting ECG was recorded. At 45 min after administration the blood pressure had fallen significantly from 216.0/117.4 mmHg to 170.0/93.3 mmHg under nifedipine and from 216.9/117.3 mmHg to 177.4/94.4 mmHg under nitrendipine. 61.6% of the nifedipine patients and 58.8% of the nitrendipine patients had already reached blood pressure values < 180/100 mmHg after 45 min and in both groups 83% of these patients were still in this limit at the end of the observation period after 4 h. Tolerability was very good in both groups.

CONCLUSION

The new dosage form of nitrendipine (vial with 1 ml of alcoholic solution) represents an alternative in the treatment of hypertensive emergency.

[Clinical courses of trisomy 18 (Edwards syndrome) - an update]

BACKGROUND

In current literature the prognosis of trisomy 18 is mainly described as inevitably lethal. After intervention of parental organisations infants have been treated with cardio surgery in the USA, later in Europe as well with good results. We report the consequences of this and similar developments on our pre- und postnatal approach after diagnosis in our department. PATIENTS AND CASE REPORTS: 2 parents decided to carry the child to term after the recommendation for abortion. According to standard perinatological aspects one child was vaginally delivered, the second with Caesarean section. After informed consent with the parents we planned a supportive management without more resuscitation than stimulation and ventilation by mask. Both children could be stabilised with nasal CPAP. The first one had been operated on a double outlet right ventricle at the age of 6 months, the second needed to be operated for diaphragm hernia. The third child had been delivered by emergency Caesarean section. A bilateral choanal atresia had been operated in the first week of life, a double outlet right ventricle at the age of 15 days. One child is fed by a nasogastric tube, one is bottle-fed and one had a percutanous gastric tube until he died due to septicaemia, all have statomotorically retardation and had periods of pulmonary hypertension. The social situation of the families is characterised by a stable parental relationship and a safe socio-economical status. None of the children had an acute lethal malformation.

DISCUSSION

In single cases a prospective management in patients with trisomy 18 can be possible. Besides medical issues, the emotional parental wish, their social network and economical status are crucial.

CONCLUSION

The prognosis of trisomy 18 is poor. 3 patients and 20 months do not allow any general statements. However, our recent experience and the courses in the recent literature show that in single cases a more prospective management is possible.

[CT Angiography for the pre- and postoperative evaluation of the thoracic aorta]

CT angiography is the imaging modality of choice for the pre- and postsurgical evaluation of patients with pathologies of the thoracic aorta. The purpose of this review is to familiarize the reader with the technical principle, recent technical developments and requirements for specific examination protocols and image interpretation, and to highlight common pathologies and findings.