A presenilin 1 mutation (L420R) in a family with early onset Alzheimer disease,seizures and cotton wool plaques,but not spastic paraparesis

Over 100 mutations in the presenilin‐1 gene (PSEN1) have been shown to result in familial early onset Alzheimer disease (EOAD), but only a relatively few give rise to plaques with an appearance like cotton wool (CWP) and/or spastic paraparesis (SP). A family with EOAD, seizures and CWP was investigated by neuropathological study and DNA sequencing of the PSEN1 gene. Aβ was identified in leptomeningeal vessels and in cerebral plaques. A single point mutation, p.L420R (g.1508T > G) that gives rise to a missense mutation in the eighth transmembrane (TM8) domain of PS1 was identified in two affected members of the family. p.L420R (g.1508T > G) is the mutation responsible for EOAD, seizures and CWP without SP in this family.     

Acetabular blood flow during Bernese periacetabular osteotomy: an intraoperative study using laser Doppler flowmetry.

BACKGROUND: The blood flow to the acetabular fragment is of some concern in juxtaarticular pelvic osteotomies used for the treatment of hip dysplasia. No direct measurements have determined the effect of the Bernese periacetabular osteotomy (PAO) on acetabular perfusion. METHODS: Acetabular perfusion was measured by means of laser Doppler flowmetry in 10 patients undergoing a PAO for symptomatic acetabular dysplasia. During the surgical procedure, the intraosseous high energy laser Doppler reliably depicts dynamic changes of small vessel blood flow. Measurements were performed after defined surgical steps to obtain sequential information on the blood perfusion of the acetabular fragment. RESULTS: After complete separation of the acetabular fragment, nine out of 10 patients had pulsatile signals, but the blood flow (BF) significantly decreased by 77%. Corrective positioning of the fragment induced no further drop of the BF signal but a loss of pulsatility in six patients. After a recovery period of about 30 min following preliminary fixation of the fragment, reestablishment of the pulsatile signal and an increase of the BF signal was seen. At termination of the surgical procedure, five out of eight patients, who could be followed throughout the whole procedure, showed a clear pulsatile signal in the supraacetabular area. Bleeding of the supraacetabular cancellous surface could be observed in all acetabula. CONCLUSION: Despite careful preservation of soft tissues during the surgical procedure, a significant reduction of the blood flow in the supraacetabular region has been observed. Nevertheless, a pulsatile signal in more than 60% of the fragments after fragment correction and an increasing signal during the recovery period showed ongoing blood perfusion indicating reversible changes in the measured supraacetabular area. All osteotomies healed within eight weeks without showing signs of necrosis during a minimum follow up of 1 year.     

Multimodality evoked potentials and early prognosis in comatose patients

In 112 comatose patients somatosensory, visual and auditory evoked potentials were registered within 36 hours after the onset of coma or admission. Main causes of coma were head injury, and intracerebral and subarachnoid haemorrhage. The initial bilateral loss of any evoked potential was associated with a mortality of 98%. Normal somatosensory evoked potentials were associated with a survival rate of 74%, while normal visual and normal auditory evoked potentials had a survival rate of 60% and 66%, respectively. It is concluded that SEPs can be valuable for the prognosis of coma after primary brain lesions.     

Development and current status of silicone oil surgery

On the basis of a series of 500 patients the authors describe the development of silicone oil surgery, the surgical technique, and present-day indications for it, as well as the results that can be achieved with this procedure. The postoperative problems (cataract, glaucoma, and keratopathy) are analyzed and guidelines presented for reducing the complication rate.     

Grenzen und Möglichkeiten der Glaskörperchirurgie bei diabetischer Retinopathie

Hintergrund: Verschiedene Indikationen für glask?rperchirurgische Eingriffe bei Komplikationen der diabetischen Retinopathie haben sich etabliert. Jedoch gibt es wenig Daten zu der Frage, in welchen Situationen auf einen Eingriff wegen aussichtsloser funktioneller Prognose verzichtet werden sollte. Material und Methode: Die Krankengeschichten von 389 Patienten, die zwischen 1990 und 1994 in unserer Klinik wegen Komplikationen der diabetischen Retinopathie vitrektomiert worden sind, wurden retrospektiv analysiert. Die Nachbeobachtung betrug mindestens 6 Monate, im Median 26 Monate. Mit multivariaten, logistischen Regressionsanalysen wurden Faktoren ermittelt, die mit schlechten postoperativen, funktionellen Ergebnissen korrelieren. Ein mathematisches Modell wurde entwickelt, welches die Einsch?tzung der Prognose für verschiedene Ausgangssituationen erlaubt. Ergebnisse: Bei 45 Augen (12%) stieg der postoperative Visus nicht über 1/50. Risikofaktoren waren Ablatio der Makula, Ausdehnung der Ablatio, Rubeosis und Dauer der Visusminderung. ?hnliche Risikofaktoren gelten auch für Revisionsoperationen. Bei einem Auge mit totaler Traktionsablatio von über 6 Monaten Dauer und Rubeosis liegt die berechnete Wahrscheinlichkeit für einen postoperativen Visus über 1/50 lediglich bei 2%. Schlu?folgerungen: Bei totaler Traktionsablatio, insbesondere bei Rubeosis und l?ngerem Bestehen der Ablatio, ist die Prognose extrem schlecht. Auf operative Ma?nahmen sollte hier verzichtet werden.      

Improved anchorage in osteoporotic vertebrae with new implant designs.

The goal of our study was to evaluate two newly developed implant designs and their behavior in terms of subsidence in lumbar vertebral bodies under cyclic loading. The new implants were evaluated in two different configurations (two small prototypes vs. one large prototype with similar load-bearing area) in comparison to a conventional screw-based implant (MACS TL). A pool of 13 spines with a total of 65 vertebrae was used to establish five testing groups of similar bone mineral density (BMD) distribution with eight lumbar vertebrae each. In additional to BMD assessment via dual-energy X-ray absorptiometry, cancellous BMD and structural parameters were determined using a new generation in vivo 3D-pQCT. The specimens were loaded sinusoidally in force control at 1 Hz for 1000 cycles at three load levels (100, 200, and 400 N). A survival analysis using the number of cycles until failure (Cox regression with covariates) was applied to reveal differences between implant groups. All new prototype configurations except the large cylinder survived significantly longer than the control group. The number of cycles until failure was significantly correlated with the structural parameter Tb.Sp. and similarly with the cancellous BMD for three of five implants. In both large prototypes the cycle number until failure significantly correlated with the preoperative distance to the upper endplates. Although the direct relationship between bone structure or density and mechanical breakage behavior cannot be conclusively proven, all the prototypes adapted for poor bone structure performed better than the comparable conventional implant.     

Radiofrequency capacitive heating of deep-seated tumours using pre-cooling of the subcutaneous tissues: results on thermometry in Dutch patients.

The capacity of a radiofrequency, 13.56 MHz, capacitive hyperthermia system using extensive pre-cooling of the subcutaneous tissue to induce locoregional deep heating has been investigated in 11 patients. Tumour location was presacral in nine--and eccentric towards the lateral side of the pelvis in two patients. For thermometry multiple catheters (mean 2.7) were inserted into the treatment volume. The mean numbers of temperature measuring points per treatment were 9.4 in tumour, 5.5 in muscle and 7.2 in subcutaneous fat. RF energy was applied after 30 min of cooling through two flexible boli perfused with saline water at 5-10 degrees C. Patient tolerance to pre-cooling was very good and after some initial discomfort the patient became rapidly accustomed to the cold water boli. For some patients better temperatures were achieved when the conventional anterior-posterior applicator set-up was replaced by a set-up with an applicator on each lateral side of the patient. As patients can tolerate temperatures within the fat tissue as high as 45.5 degrees C without complaining it appears important to monitor the temperature at the transition of fat to muscle tissue to prevent subcutaneous burns. The study shows that pre-cooling cannot avoid preferential heating at the interface from fat to muscle tissue. In this patient group the quality of the hyperthermia treatment appeared to be rather poor: 60% of the measured tumour temperatures were below 40 degrees D.