Rudolf Albert Venbrocks

Intra-articular injections of high-molecular-weight hyaluronic acid have biphasic effects on joint inflammation and destruction in rat antigen-induced arthritis.

To assess the potential use of hyaluronic acid (HA) as adjuvant therapy in rheumatoid arthritis, the anti-inflammatory and chondroprotective effects of HA were analysed in experimental rat antigen-induced arthritis (AIA). Lewis rats with AIA were subjected to short-term (days 1 and 8, n = 10) or long-term (days 1, 8, 15 and 22, n = 10) intra-articular treatment with microbially manufactured, high-molecular-weight HA (molecular weight, 1.7 × 106 Da; 0.5 mg/dose). In both tests, 10 buffer-treated AIA rats served as arthritic controls and six healthy animals served as normal controls. Arthritis was monitored by weekly assessment of joint swelling and histological evaluation in the short-term test (day 8) and in the long-term test (day 29). Safranin O staining was employed to detect proteoglycan loss from the epiphyseal growth plate and the articular cartilage of the arthritic knee joint. Serum levels of IL-6, tumour necrosis factor alpha and glycosaminoglycans were measured by ELISA/kit systems (days 8 and 29). HA treatment did not significantly influence AIA in the short-term test (days 1 and 8) but did suppress early chronic AIA (day 15, P < 0.05); however, HA treatment tended to aggravate chronic AIA in the long-term test (day 29). HA completely prevented proteoglycan loss from the epiphyseal growth plate and articular cartilage on day 8, but induced proteoglycan loss from the epiphyseal growth plate on day 29. Similarly, HA inhibited the histological signs of acute inflammation and cartilage damage in the short-term test, but augmented acute and chronic inflammation as well as cartilage damage in the long-term test. Serum levels of IL-6, tumour necrosis factor alpha, and glycosaminoglycans were not influenced by HA. Local therapeutic effects of HA in AIA are clearly biphasic, with inhibition of inflammation and cartilage damage in the early chronic phase but with promotion of joint swelling, inflammation and cartilage damage in the late chronic phase.

Autologous chondrocyte transplantation in the ankle joint. Rational or irrational

Ankle sprains are one the most common injuries of the lower limb. Fractures, ligamentous lesions, and cartilaginous damage are often associated. Nevertheless the injury is often misjudged and concomitant chondral lesions are assessed late. In the case of a symptomatic osteocartilaginous lesion of the talus, which can be illustrated by MRI or X-ray, operative intervention is indicated. Methods such as microfracturing, mosaicplasty, and autologous chondrocyte transplantation (ACT) are in clinical use. The latter is well known and being established as the treatment of choice for large cartilage defects in the knee. Due to the good results in the knee and the technological improvements (three-dimensional tissue constructs seeded with autologous chondrocytes) this method is being increasingly applied for cartilage lesions of the talus. In contrast to the mosaicplasty donor site morbidity is low and the size of the defect is not a limiting factor. The current studies about ACT of the talus show a stable repair of the defect with mostly hyaline-like cartilage and high patient satisfaction. Therefore, the procedure can be recommended for lesions>1 cm2. Concomitant treatment of posttraumatic deformities (malalignment), ligamentous instabilities, and especially the reconstruction of bony defects are compulsory.

Autologe Chondrozytentransplantation am oberen Sprunggelenk

Ankle sprains are one the most common injuries of the lower limb. Fractures, ligamentous lesions, and cartilaginous damage are often associated. Nevertheless the injury is often misjudged and concomitant chondral lesions are assessed late. In the case of a symptomatic osteocartilaginous lesion of the talus, which can be illustrated by MRI or X-ray, operative intervention is indicated. Methods such as microfracturing, mosaicplasty, and autologous chondrocyte transplantation (ACT) are in clinical use. The latter is well known and being established as the treatment of choice for large cartilage defects in the knee. Due to the good results in the knee and the technological improvements (three-dimensional tissue constructs seeded with autologous chondrocytes) this method is being increasingly applied for cartilage lesions of the talus. In contrast to the mosaicplasty donor site morbidity is low and the size of the defect is not a limiting factor. The current studies about ACT of the talus show a stable repair of the defect with mostly hyaline-like cartilage and high patient satisfaction. Therefore, the procedure can be recommended for lesions>1 cm2. Concomitant treatment of posttraumatic deformities (malalignment), ligamentous instabilities, and especially the reconstruction of bony defects are compulsory.

Entwicklung des Lernzielkatalogs „Muskuloskelettale Erkrankungen, Verletzungen und traumatische Notfälle“ für Orthopädie-Unfallchirurgie im Medizinstudium

ZusammenfassungHintergrundMit der Entwicklung des gemeinsamen Faches Orthopädie-Unfallchirurgie bedarf es neben der Zusammenführung und Überarbeitung der Weiterbildungsinhalte des ärztlichen Nachwuchses auch der Erstellung eines für Deutschland einheitlichen Lernzielkatalogs, der die Grundlage der studentischen Lehre in der Orthopädie und Unfallchirurgie an den deutschen Fakultäten und Lehrkrankenhäusern bilden soll.Material und MethodeAusgehend vom Frankfurter Lernzielkatalog für Unfallchirurgie und dem Ulmer Lernzielkatalog für Orthopädie wurde von einer Expertenkommission der gemeinsame Katalog für das Fach Orthopädie und Unfallchirurgie entwickelt. Durch Vertreter beider Fächer erfolgte die Definition der Lernziele und anschließende Gliederung und Priorisierung in sog. Ebenen und Bereiche des kognitiven Wissens, Kompetenzstufen psychomotorischer Fertigkeiten (Skills) sowie emotionales Wissen und Kompetenz.ErgebnisInsgesamt wurden 283 Lernziele formuliert. Der „allgemeine Teil operativer Fachgebiete“ umfasst 120 Lernziele, die sich in 39 Items kognitiven Inhalts und 83 Skills unterteilen, 2 Lernziele beinhalten gleichzeitig sowohl Wissen als auch Skills. Der „spezielle Teil Orthopädie/Unfallchirurgie“ umfasst insgesamt 141 Lernziele unterteilt in 138 Lernziele mit Wissensinhalten sowie 6 Skills, 3 Lernziele beziehen sich auf Wissen sowie Skills. 22 Lerninhalte beziehen sich auf den Bereich „emotionales Wissen und Kompetenz“.SchlussfolgerungTrotz der erst jungen Verbindung der beiden Fächer Orthopädie und Unfallchirurgie konnte nicht nur eine „Themensammlung“, sondern ein gemeinsamer Lernzielkatalog für die studentische Lehre erarbeitet werden. Dieser hat nach der Verabschiedung durch die Ordinarienkonvente der Unfallchirurgen und Orthopäden bundesweiten Empfehlungscharakter. Mit der Konsentierung von Lernzielen sind die Weichen für eine zukunftorientierte moderne Lehre gestellt. Anhand der im Lernzielkatalog enthaltenen Empfehlungen zur Gewichtung der Inhalte, zur Verknüpfung mit anderen Fächern und zum Einsatz geeigneter Lehrmethoden, können die einzelnen Lernziele an den jeweiligen Fakultäten pragmatisch und unter Wahrung der Freiheit der Lehre umgesetzt werden.AbstractBackgroundThe development towards a combined speciality of orthopaedic and trauma surgery requires not only consolidation and revision of the postgraduate education training programme but also the development of a catalogue of learning objectives as a uniform basis for undergraduate medical training in the new speciality at German medical schools and teaching hospitals. Materials and methodsBased on the Frankfurt catalogue of learning objectives for trauma surgery and the Ulm catalogue of learning objectives for orthopaedics, a task force of experts developed a combined catalogue of learning objectives for the new speciality. Experts from both specialities classified the learning objectives into two levels of knowledge and four grades of skills competence, in addition to objectives for attitudes and social competence.ResultsThe section on general operative specialities contains 120 items classified into 39 learning objectives for knowledge and 83 for skills. Two learning objectives comprise both knowledge and skills. The section on orthopaedic and trauma surgery comprises 141 learning objectives, including six items for skills and 138 for knowledge, as well as three learning objectives for both knowledge and skills. In addition, 22 learning objectives deal with aspects of attitude and social competence.ConclusionAlthough this alliance of orthopaedics and trauma surgery is recent, the commission has developed not only a collection of topics but a joint catalogue of learning objectives for undergraduate training that can be used nationwide. This catalogue paves the way for modern education that looks to the future. The integrated recommendations for content prioritisation, links to other subjects and specialities, and the integration of didactic methods facilitate local implementation of the learning objectives without loss of academic freedom.BACKGROUND The development towards a combined speciality of orthopaedic and trauma surgery requires not only consolidation and revision of the postgraduate education training programme but also the development of a catalogue of learning objectives as a uniform basis for undergraduate medical training in the new speciality at German medical schools and teaching hospitals. MATERIALS AND METHODS Based on the Frankfurt catalogue of learning objectives for trauma surgery and the Ulm catalogue of learning objectives for orthopaedics, a task force of experts developed a combined catalogue of learning objectives for the new speciality. Experts from both specialities classified the learning objectives into two levels of knowledge and four grades of skills competence, in addition to objectives for attitudes and social competence. RESULTS The section on general operative specialities contains 120 items classified into 39 learning objectives for knowledge and 83 for skills. Two learning objectives comprise both knowledge and skills. The section on orthopaedic and trauma surgery comprises 141 learning objectives, including six items for skills and 138 for knowledge, as well as three learning objectives for both knowledge and skills. In addition, 22 learning objectives deal with aspects of attitude and social competence. CONCLUSION Although this alliance of orthopaedics and trauma surgery is recent, the commission has developed not only a collection of topics but a joint catalogue of learning objectives for undergraduate training that can be used nationwide. This catalogue paves the way for modern education that looks to the future. The integrated recommendations for content prioritisation, links to other subjects and specialities, and the integration of didactic methods facilitate local implementation of the learning objectives without loss of academic freedom.

Total hip replacement through a minimally invasive, anterolateral approach with the patient supine.

ZusammenfassungOperationszielRasche postoperative Mobilisation und Wiederherstellung einer schmerzfreien Gelenkfunktion durch standardisierten, minimalinvasiven Zugang zur Implantation von Hüftendoprothesen in Rückenlage ohne Berücksichtigung der Art des Implantats.IndikationenPrimäre und sekundäre Koxarthrosen.Hüftkopfnekrosen.KontraindikationenVoroperierte Patienten mit Deformitäten des koxalen Femurendes und ausgedehnten Vernarbungen.OperationstechnikLagerung auf dem Rücken. Hautschnitt ventral des Trochanter major in Höhe des Intervalls zwischen Musculus tensor fasciae latae und Tractus iliotibialis parallel zum Azetabulum, von distal nach proximal leicht ansteigend. Inzision des Tractus iliotibialis dorsal des Intervalls. Koagulation kreuzender Gefäße. Stumpfes Vorgehen auf den Schenkelhals ventral der Glutealmuskulatur. L-förmige Inzision der ventralen Kapsel mit Basis am lateralen Schenkelhals. Schenkelhalsosteotomie und Resektion des Hüftkopfes. Mobilisation der dorsalen Kapsel durch Inzision am Übergang zum Femur. Unter Schutz von Hohmann- Hebeln Präparation des Azetabulums und Implantation der Endoprothesenpfanne. Unter Adduktion, Außenrotation und Hyperextension Präparation des koxalen Femurendes und Implantation des Prothesenstiels. Nach Reposition adaptierende Nähte der kranialen Kapselanteile. Einlegen einer intraartikulären Redon-Drainage. Einzelknopfnähte des Tractus iliotibialis. Subkutane Redon- Drainage. Subkutannaht. Hautnaht. Steriler Verband. Abschließende Röntgenkontrolle anteroposterior.WeiterbehandlungMobilisation ab dem 1. postoperativen Tag. Zunehmende Belastung des operierten Beins in Abhängigkeit von den flexlokalen Schmerzen. Ab dem 2.–3. Tag Vier-Punkt-Gang. Ab dem 4. Tag Treppensteigen.ErgebnisseZwischen September 2004 und Juli 2006 wurden 195 Patienten operiert (105 Frauen, 90 Männer, Durchschnittsalter 64,4 Jahre [37,1–88,4 Jahre]). Operationsdauer durchschnittlich 63 min (35–105 min). Durchschnittlicher intraoperativer Blutverlust 437 ml (20–800 ml). Postoperative Kontrolluntersuchung aller Patienten nach 3, 6 und 12 Monaten, danach jährlich.Schnelles Erreichen der vollen Belastung und Beweglichkeit innerhalb der ersten Wochen. Komplikationen: zwei postoperative periprothetische Frakturen. Keine periartikulären Ossifikationen > Brooker II. Keine revisionspflichtigen Hämatome. Keine neurologischen Störungen.AbstractObjectiveEarly postoperative mobilization and restoration of pain-free joint function by implantation of a total hip replacement through a standardized, minimally invasive approach regardless of the type of implant with the patient in the supine position.IndicationsPrimary and secondary coxarthrosis.Femoral head necrosis.ContraindicationsPreviously operated patients with deformities of the coxal end of the femur and extensive scarring.Surgical TechniqueSupine position. Skin incision anterior to the greater trochanter at the level of the interval between the tensor fasciae latae muscle and the iliotibial tract parallel to the acetabulum ascending slightly from distal to proximal. Incision of the iliotibial tract posterior to the interval. Coagulation of intersecting vessels. Blunt dissection to the femoral neck anterior to the gluteal muscles. L-shaped incision of the anterior capsule with the base at the lateral femoral neck. Femoral neck osteotomy and resection of the femoral head. Mobilization of the posterior capsule by incision at the junction with the femur. Insertion of Hohmann elevators to protect the tissue, dissection of the acetabulum and implantation of the acetabular component. In adduction, external rotation and hyperextension, dissection of the coxal end of the femur, and implantation of the prosthetic stem. After reduction, adaptive suture of the cranial capsular parts. Insertion of intraarticular Redon drains. Interrupted suture of the iliotibial tract. Subcutaneous Redon drains. Subcutaneous suture. Skin suture. Sterile dressing. Final radiologic evaluation in anteroposterior view.Postoperative ManagementMobilization from postoperative day 1. Increased loading on the operated leg depending on local pain. Four-point gait from day 2–3. Stair-climbing from day 4.ResultsFrom September 2004 to July 2006, 195 patients were operated on (105 women, 90 men, average age 64.4 years [37.1–88.4 years]). Average operating time 63 min (35–105 min). Average intraoperative blood loss 437 ml (20–800 ml). Postoperative follow-up of all patients at 3, 6, and 12 months, and then annually.Early restoration of full weight-bearing ability and range of motion within the first few weeks. Complications: two postoperative periprosthetic fractures. No periarticular ossifications > Brooker II. No hematoma requiring revision. No neurologic deficits.

Der minimalinvasive, anterolaterale Zugang zum Hüftgelenk zur Implantation von Endoprothesen in Rückenlage

ZusammenfassungOperationszielRasche postoperative Mobilisation und Wiederherstellung einer schmerzfreien Gelenkfunktion durch standardisierten, minimalinvasiven Zugang zur Implantation von Hüftendoprothesen in Rückenlage ohne Berücksichtigung der Art des Implantats.IndikationenPrimäre und sekundäre Koxarthrosen.Hüftkopfnekrosen.KontraindikationenVoroperierte Patienten mit Deformitäten des koxalen Femurendes und ausgedehnten Vernarbungen.OperationstechnikLagerung auf dem Rücken. Hautschnitt ventral des Trochanter major in Höhe des Intervalls zwischen Musculus tensor fasciae latae und Tractus iliotibialis parallel zum Azetabulum, von distal nach proximal leicht ansteigend. Inzision des Tractus iliotibialis dorsal des Intervalls. Koagulation kreuzender Gefäße. Stumpfes Vorgehen auf den Schenkelhals ventral der Glutealmuskulatur. L-förmige Inzision der ventralen Kapsel mit Basis am lateralen Schenkelhals. Schenkelhalsosteotomie und Resektion des Hüftkopfes. Mobilisation der dorsalen Kapsel durch Inzision am Übergang zum Femur. Unter Schutz von Hohmann- Hebeln Präparation des Azetabulums und Implantation der Endoprothesenpfanne. Unter Adduktion, Außenrotation und Hyperextension Präparation des koxalen Femurendes und Implantation des Prothesenstiels. Nach Reposition adaptierende Nähte der kranialen Kapselanteile. Einlegen einer intraartikulären Redon-Drainage. Einzelknopfnähte des Tractus iliotibialis. Subkutane Redon- Drainage. Subkutannaht. Hautnaht. Steriler Verband. Abschließende Röntgenkontrolle anteroposterior.WeiterbehandlungMobilisation ab dem 1. postoperativen Tag. Zunehmende Belastung des operierten Beins in Abhängigkeit von den flexlokalen Schmerzen. Ab dem 2.–3. Tag Vier-Punkt-Gang. Ab dem 4. Tag Treppensteigen.ErgebnisseZwischen September 2004 und Juli 2006 wurden 195 Patienten operiert (105 Frauen, 90 Männer, Durchschnittsalter 64,4 Jahre [37,1–88,4 Jahre]). Operationsdauer durchschnittlich 63 min (35–105 min). Durchschnittlicher intraoperativer Blutverlust 437 ml (20–800 ml). Postoperative Kontrolluntersuchung aller Patienten nach 3, 6 und 12 Monaten, danach jährlich.Schnelles Erreichen der vollen Belastung und Beweglichkeit innerhalb der ersten Wochen. Komplikationen: zwei postoperative periprothetische Frakturen. Keine periartikulären Ossifikationen > Brooker II. Keine revisionspflichtigen Hämatome. Keine neurologischen Störungen.AbstractObjectiveEarly postoperative mobilization and restoration of pain-free joint function by implantation of a total hip replacement through a standardized, minimally invasive approach regardless of the type of implant with the patient in the supine position.IndicationsPrimary and secondary coxarthrosis.Femoral head necrosis.ContraindicationsPreviously operated patients with deformities of the coxal end of the femur and extensive scarring.Surgical TechniqueSupine position. Skin incision anterior to the greater trochanter at the level of the interval between the tensor fasciae latae muscle and the iliotibial tract parallel to the acetabulum ascending slightly from distal to proximal. Incision of the iliotibial tract posterior to the interval. Coagulation of intersecting vessels. Blunt dissection to the femoral neck anterior to the gluteal muscles. L-shaped incision of the anterior capsule with the base at the lateral femoral neck. Femoral neck osteotomy and resection of the femoral head. Mobilization of the posterior capsule by incision at the junction with the femur. Insertion of Hohmann elevators to protect the tissue, dissection of the acetabulum and implantation of the acetabular component. In adduction, external rotation and hyperextension, dissection of the coxal end of the femur, and implantation of the prosthetic stem. After reduction, adaptive suture of the cranial capsular parts. Insertion of intraarticular Redon drains. Interrupted suture of the iliotibial tract. Subcutaneous Redon drains. Subcutaneous suture. Skin suture. Sterile dressing. Final radiologic evaluation in anteroposterior view.Postoperative ManagementMobilization from postoperative day 1. Increased loading on the operated leg depending on local pain. Four-point gait from day 2–3. Stair-climbing from day 4.ResultsFrom September 2004 to July 2006, 195 patients were operated on (105 women, 90 men, average age 64.4 years [37.1–88.4 years]). Average operating time 63 min (35–105 min). Average intraoperative blood loss 437 ml (20–800 ml). Postoperative follow-up of all patients at 3, 6, and 12 months, and then annually.Early restoration of full weight-bearing ability and range of motion within the first few weeks. Complications: two postoperative periprosthetic fractures. No periarticular ossifications > Brooker II. No hematoma requiring revision. No neurologic deficits.

Overwhelming septic infection with a multi-resistant Staphylococcus aureus (MRSA) after total knee replacement

IntroductionThe incidence of early deep infection after arthroplasty of the knee is very low but could represent a serious future problem.Material and methodsThe authors report on a 71-year-old woman with gonarthritis who was supplied with a total knee endoprosthesis and developed a local infection followed by septic shock.ResultsThe infection was evidently caused by a multiresistant Staphylococcus aureus (Staph. aureus). The primary clinical signs closely resembled a necrotizing fasciitis. Systemic and local application of vancomycin led to an improvement of the symptoms at secondary sites, but only the amputation of the primarily infected leg was lifesaving.ConclusionIn order to prevent such events, the authors recommend a number of additional presurgical measures. Firstly, a swab from the nose and throat should be taken prior to an elective surgery in patients with elevated risk of immunodeficiency, for example in patients with diabetes. The diabetes should be adequately treated before an elective operation is undertaken. Secondly, an early punction of the knee joint should be carried out if there is any doubt regarding inflammation. Isolated infectious agents should be grounds for early revision, which should always be completed with a rinsing procedure and with adequate antibiotics. Immunotherapy should be taken into consideration. Antiepidemic measures are recommended in cases with known Staph. aureus.

Acetylcholinesterase assay for cerebrospinal fluid using bupivacaine to inhibit butyrylcholinesterase

BackgroundMost test systems for acetylcholinesterase activity (E.C.3.1.1.7.) are using toxic inhibitors (BW284c51 and iso-OMPA) to distinguish the enzyme from butyrylcholinesterase (E.C.3.1.1.8.) which occurs simultaneously in the cerebrospinal fluid. Applying Ellmans colorimetric method, we were looking for a non-toxic inhibitor to restrain butyrylcholinesterase activity. Based on results of previous in vitro studies bupivacaine emerged to be a suitable inhibitor.ResultsPharmacokinetic investigations with purified cholinesterases have shown maximum inhibition of butyrylcholinesterase activity and minimal interference with acetylcholinesterase activity at bupivacaine final concentrations between 0.1 and 0.5 mmol/l. Based on detailed analysis of pharmacokinetic data we developed three equations representing enzyme inhibition at bupivacaine concentrations of 0.1, 0.2 and 0.5 mmol/l. These equations allow us to calculate the acetylcholinesterase activity in solutions containing both cholinesterases utilizing the extinction differences measured spectrophotometrically in samples with and without bupivacaine. The accuracy of the bupivacaine-inhibition test could be confirmed by investigations on solutions of both purified cholinesterases and on samples of human cerebrospinal fluid. If butyrylcholinesterase activity has to be assessed simultaneously an independent test using butyrylthiocholine iodide as substrate (final concentration 5 mmol/l) has to be conducted.ConclusionsThe bupivacaine-inhibition test is a reliable method using spectrophotometrical techniques to measure acetylcholinesterase activity in cerebrospinal fluid. It avoids the use of toxic inhibitors for differentiation of acetylcholinesterase from butyrylcholinesterase in fluids containing both enzymes. Our investigations suggest that bupivacaine concentrations of 0.1, 0.2 or 0.5 mmol/l can be applied with the same effect using 1 mmol/l acetylthiocholine iodide as substrate.

Butyrylcholinesterase in lumbar and ventricular cerebrospinal fluid

Objectives– This study establishes reference data for human lumbar CSF butyrylcholinesterase (E.C.3.1.1.8.) activity and investigates the enzyme activity in ventricular CSF. We comment on the relationship between CSF butyrylcholinesterase activity and other laboratory parameters. Subjects and methods– We investigated 64 lumbar CSF samples obtained from a clinically healthy population and 169 ventricular CSF samples collected from 90 neurosurgical patients. Results– The reference range we recommend for lumbar CSF butyrylcholinesterase activity is 5.4 to 17.0 nmol/min×ml. The majority of ventricular butyrylcholinesterase activities in our patient subset ranged up to 5 nmol/min×ml. Conclusions– We established the relative influence of serum and CNS components on total CSF butyrylcholinesterase activity. The CNS fraction predominates the total butyrylcholinesterase activity in normal lumbar CSF. In ventricular CSF enzyme influx from serum outweighs the CNS component.

Acetylcholinesterase in lumbar and ventricular cerebrospinal fluid.

BACKGROUND Soluble acetylcholinesterase (AChE, E.C. 3.1.1.7.) is released by neurons, glial and meningeal cells into the CSF. AChE activity in cerebrospinal fluid (CSF) is altered in various disorders of the nervous system. The objects of this study are to define a reference range for CSF AChE activity in human lumbar CSF, to prove that the enzyme activity does not depend on the blood/CSF barrier function, and to provide information about AChE in ventricular CSF. In addition, drugs used in neurosurgical care have been examined for their in vitro effects on CSF AChE activity to exclude interference with the test system. METHODS We tested the AChE activity in 64 lumbar CSF samples collected from a clinically healthy population and in 169 ventricular CSF samples obtained from 90 neurosurgical patients. AChE activity was assayed with our inhibitor-free test procedure. RESULTS The reference range determined for lumbar CSF AChE activity is 9.2-24.4 nmol/min per ml. Lumbar CSF AChE activity does not correlate with parameters characterising the status of the blood/CSF barrier. Ventricular puncture is only justified for underlying pathology making it impossible to provide reference data for ventricular CSF. Most measurements reveal ventricular enzyme activity below 4 nmol/min per ml. CONCLUSION The results of this study suggest the utility of lumbar CSF AChE activity as a measure of specific secretory function in enzyme releasing cells of the nervous system.