Joachim Oberle - Academia.edu (original) (raw)
Papers by Joachim Oberle
Spine, Jan 15, 2015
This is a prospective, multicenter cohort study including 8 medical centers in the metropolitan a... more This is a prospective, multicenter cohort study including 8 medical centers in the metropolitan area of the Canton Zurich, Switzerland. To examine whether outcome and quality of life might improve after decompression surgery for degenerative lumbar spinal stenosis (DLSS) even in patients older than 80 years and to compare data with a younger patient population from our own patient collective. Lumbar decompression surgery without fusion has been shown to improve quality of life in lumbar spinal canal stenosis. In the population older than 80 years, treatment recommendations for DLSS show conflicting results. Eight centers in the metropolitan area of Zurich, Switzerland agreed on the classification of DLSS, surgical principles, and follow-up protocols. Patients were followed from baseline, at 6 months, and 12 months. Baseline characteristics were analyzed with 5 different questionnaires "Spinal Stenosis Measure, Feeling Thermometer, Numeric Rating Scale, 5D-3L, and Roland and Mor...
Neurosurgical review, 2009
In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage s... more In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage subsidence and segmental kyphosis seen. The aim of the present study is to assess whether the cage design influences the extent of correction loss during follow-up. Sixty patients with single-level cervical disc herniation were randomly treated with two different cervical inter-body cages (group 1: Solis cage, Stryker Company and group 2: Shell cage, AMT Company). Clinical and radiological follow-up was done before and after surgery, 3 and 6 months post-surgery. Clinical follow-up was done with the help of Odom's criteria. Both groups were similar in the baseline parameters (age, sex, treated level). Statistically, the subsidence was significantly higher at 3 and 6-month follow-ups in group 1 than in group 2, however, clinical results showed no significant differences. In 67%, subsidence was seen in the anterior lower aspect of the treated segment. Segmental kyphosis was seen in seven...
Cancer, Jan 18, 2016
A population-based analysis of patients with glioma diagnosed between 1980 and 1994 in the Canton... more A population-based analysis of patients with glioma diagnosed between 1980 and 1994 in the Canton of Zurich in Switzerland confirmed the overall poor prognosis of glioblastoma. To explore changes in outcome, registry data were reevaluated for patients diagnosed between 2005 and 2009. Patients with glioblastoma who were diagnosed between 2005 and 2009 were identified by the Zurich and Zug Cancer Registry. The prognostic significance of epidemiological and clinical data, isocitrate dehydrogenase 1 (IDH1)(R132H) mutation status, and O6 methylguanine DNA methyltransferase (MGMT) promoter methylation status was analyzed using the Kaplan-Meier method and the Cox proportional hazards model. A total of 264 patients with glioblastoma were identified, for an annual incidence of 3.9 compared with the previous incidence of 3.7. The mean age of the patients at the time of diagnosis was 59.5 years in the current cohort compared with 61.3 years previously. The overall survival (OS) rate was 46.4% ...
Klinische Neurophysiologie
Zentralblatt für Neurochirurgie
Many attempts have been made in the past to find predictive factors concerning patients operated ... more Many attempts have been made in the past to find predictive factors concerning patients operated on because of ulnar nerve entrapment at the elbow. The factors most frequently discussed in the literature are the patient's age, the importance of the preoperative neurological deficit, the duration of symptoms, accompanying diseases as diabetes mellitus or alcoholism and preoperative electrophysiological findings (EMG and conduction velocity measurements). With the exception of the electrophysiological findings, which uniformly are considered to be without predictive value, all other factors mentioned above are discussed controversly. In 1972 Kline and Nulsen [12] have shown, that intraoperatively evoked nerve action potentials across a traumatic nerve lesion can provide information about nerve regeneration. This information helps to choose the appropriate surgical procedure namely either neurolysis or neuroma resection and grafting. However there are no reports dealing with this method in nerve entrapment syndromes. We present the results of 17 patients with ulnar nerve entrapment at the elbow. They were operated on in our hospital between 1989 and 1992 by simple decompression or by anterior transposition of the nerve. In each of them we tried to record electrically evoked nerve action potentials intraoperatively and compared preoperative clinical findings with the potentials recorded. Our main interest was to find out, if the potentials have any predictive value regarding the clinical outcome. In 16 of 17 patients we were able to record a reproducable nerve action potential. Amplitudes varied between 3.4 and 140 uV. Conduction velocities of the fastest fibers ranged from 17 to 71 m/s, while potential duration varied between 1.3 to more than 8 ms.(ABSTRACT TRUNCATED AT 250 WORDS)
Acta Physiologica Scandinavica
OBERLE, J., ELAM, M., KARLSSON, T . & WALLIN, B. G. 1988. Temperature-dependent interaction betwe... more OBERLE, J., ELAM, M., KARLSSON, T . & WALLIN, B. G. 1988. Temperature-dependent interaction between vasoconstrictor and vasodilator mechanisms in human skin. Acta Physiol Scand 132, 459-469.
The American journal of physiology
The effects of sympathetic nerve stimulation on vasoconstrictor responses and overflow of norepin... more The effects of sympathetic nerve stimulation on vasoconstrictor responses and overflow of norepinephrine (NE) and neuropeptide Y-like immunoreactivity (NPY-LI) were studied in the dog gracilis muscle and pig spleen in vivo. A continuous regular impulse activity was compared with irregular human sympathetic and regular bursting patterns. During control conditions, stimulation with the irregular activity induced larger peak vasoconstriction than the regular activity at 0.59 Hz, but not at higher frequencies in the muscle, at 0.59 and 2.0 Hz in the spleen. The nerve stimulation-evoked overflow of NE and NPY-LI from the muscle were not influenced by the pattern of stimulation. The overflow of NPY-LI, but not that of NE, from the spleen was enhanced by the irregular activity at 0.59 and 2.0 Hz, and both NPY-LI and NE overflows were enhanced by regular burst activity at 2.0 Hz. After blockade of alpha- and beta-adrenoceptors by phenoxybenzamine and propranolol, respectively, which enhanced nerve stimulation-evoked overflow of both NE and NPY-LI, the NE overflow from the muscle evoked by the irregular activity was slightly larger at 0.59 Hz but smaller at higher frequencies compared with that evoked by regular activity, whereas the detectable overflow of NPY-LI was not largely influenced by the stimulation pattern. In conclusion, both the vasoconstrictor response and the overflow of NPY-LI and NE seem to be influenced by the pattern and frequency of sympathetic nerve stimulation.
Der Nervenarzt
Endoscopic carpal tunnel release is a new technique for treatment of carpal tunnel syndrome. The ... more Endoscopic carpal tunnel release is a new technique for treatment of carpal tunnel syndrome. The benefits of this procedure are a small skin wound with less local pain, the fact that the hand can quickly be used again, and earlier return to work or other activities. We present the preliminary results of the 3-month follow-up of 88 patients out of a prospective study of 100 patients. All patients were operated on using the one-port technique. Six additional decompressions had to be abandoned and open release was performed. Of the patients with pain, 73.6% (68/88) were completely pain-free and in 13.2% (9/68) pain improved in more than 50%. Subjective symptoms like paresthesia and numbness of the hand disappeared completely in 77.2% (64/83). Sensory deficits disappeared in 50% (33/66). Ten of 17 patients with preoperative paresis of the abductor pollicis brevis muscle and 11/14 with paresis of the opponens pollicis muscle had normal motor function 3 months after the operation. The complication rate concerning nerve lesions was 2.3%. The return to work time was 21 days (range 3-49 days). According to clinical symptoms, our preliminary results do not seem to have any benefits compared to the conventional open technique, and the costs for the endoscopic procedure are markedly higher. The complication rate after the learning curve period is approximately the same as open carpal tunnel release.
Zentralblatt für Neurochirurgie
The sural nerve is the most common nerve serving as a donor in an autologeous nerve grafting proc... more The sural nerve is the most common nerve serving as a donor in an autologeous nerve grafting procedure. However, there is a certain risk for the development of painful paraesthesias at the donor site. Patients in whom a short segment of the sural nerve was resected are suspected to have a greater risk. In a retrospective study we investigated the incidence of painful paraesthesias following removal of a segment of the sural nerve for a grafting procedure. The study includes 41 patients, who were followed at least for one year after surgery (mean 30 months). 9 patients (22%) complained of persisting painful paraesthesias at the donor site suggesting a neuroma at the proximal stump of the sural nerve. The comparison of the length of the nerve segment harvested for grafting shows a tendency for patients with shorter segments having a greater risk to develop painful paraesthesias. However, the difference between the two groups was statistically not significant.
Der Nervenarzt
A 27-year-old otherwise healthy male presented with an isolated but complete axillary nerve palsy... more A 27-year-old otherwise healthy male presented with an isolated but complete axillary nerve palsy after excessive squash playing. When repeated electromyographic investigations showed no signs of reinnervation in the deltoid muscle, surgery was performed in order to restore nerve function. Intraoperatively, the nerve showed a short segment of thinning about 2 cm distally the nerve's origin from the posterior fascicle. As intraoperative electrophysiological testing was also negative (no electrically evoked nerve action potentials across the lesion) the suspicious nerve segment was resected and nerve continuity restored by sural grafts. Histologically, no intact nerve structures could be found at the site of the thinning. Most likely the lesion was caused by traction forces. Follow-up studies showed reinnervation of deltoid function over time.
Zentralblatt für Neurochirurgie
Motor distal latency (MDL) is one of the most important parameters in the electrodiagnosis of car... more Motor distal latency (MDL) is one of the most important parameters in the electrodiagnosis of carpal tunnel syndrome (CTS). In a retrospective study of 1816 open surgical decompressions for CTS, a total of 612 postoperative motor nerve conduction measurements on 485 hands could be evaluated. In patients with good or satisfactory results after carpal tunnel release, an average improvement of MDL of 1.0 ms after 9-13 days, and of 2.2 ms after 1 year and longer was found. The individual motor nerve conduction improvement was in close correlation with the extent of preoperative prolongation of the MDL. Whereas relief of symptoms can be noted almost immediately, prolonged latencies often do not return to normal, even when the study is done a year later. Of the 10 patients with persisting symptoms, four had a new postoperative impairment of MDL, and also four had a marked improvement, whereas it remained unchanged in two. Patients with severe recurrent CTS presented in 11 out of 31 cases ...
Praxis, Jan 20, 2012
We report the case of a 30-year-old female patient who underwent unilateral transverse sinus sten... more We report the case of a 30-year-old female patient who underwent unilateral transverse sinus stenosis stenting due to a newly diagnosed idiopathic intracranial hypertension (Pseudotumor cerebri) with symptoms of papilledema, decreased visual acuity and headache. Resolution of the symptoms and improvement of magnetic resonance and ophthalmiologic findings could be documented.
Spine, 2008
Prospective controlled clinical study. The aim of this prospective nonrandomized study is to eval... more Prospective controlled clinical study. The aim of this prospective nonrandomized study is to evaluate the recurrence rate and the clinical outcome of patients undergoing sole sequestrectomy and compare them with a standard treatment group. While performing microsurgical disc excision, extruded disc fragments and loosened or degenerated parts of the nucleus are removed. It is controversial whether this strategy is always necessary. Within the literature, there is only little information about the results of exclusive sequestrectomy. Criteria for performing a sole sequestrectomy were a nonbulging disc and only small or medium perforations within the fibrous ring. According to these criteria, the authors recruited 90 patients for the sequestrectomy group. The control group was operated in standard microsurgical manner during the same time, including 84 patients. A detailed analysis of the actual pain status, the functional capacity (Hannover Activities of Daily Living Questionnaire, FFbH) and eventually additional spinal operations during the follow-up of 2 years was performed. Mean Funktionsfragebogen Hannover (FFbH) score at the follow-up was 76% in the sequestrectomy group and 77.6% in the control group. This difference is statistically not significant. There were 2 recurrences in the sequestrectomy group at the same level and 1 postoperative instability requiring a fusion procedure. In the control group, there were 2 recurrences and 1 secondary lateral spinal stenosis that led to reoperations. The competence of the fibrous ring influenced significantly the success of a simple sequestrectomy. The sole sequestrectomy group revealed similar results compared with the standard microdiscectomy group. There is a comparable low number of recurrences in both groups. This is probably caused by the consequent selection of patients for sequestrectomy according to well-defined criteria.
Neurosurgical Review, 2009
In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage s... more In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage subsidence and segmental kyphosis seen. The aim of the present study is to assess whether the cage design influences the extent of correction loss during follow-up. Sixty patients with single-level cervical disc herniation were randomly treated with two different cervical inter-body cages (group 1: Solis cage, Stryker Company and group 2: Shell cage, AMT Company). Clinical and radiological follow-up was done before and after surgery, 3 and 6 months post-surgery. Clinical follow-up was done with the help of Odom's criteria. Both groups were similar in the baseline parameters (age, sex, treated level). Statistically, the subsidence was significantly higher at 3 and 6-month follow-ups in group 1 than in group 2, however, clinical results showed no significant differences. In 67%, subsidence was seen in the anterior lower aspect of the treated segment. Segmental kyphosis was seen in seven patients of group 1 and two patients of group 2. A significant correlation is found between Odom's criteria and subsidence. Although there was no significant difference in a short-term clinical result between the two treatment groups, we recommend the use of cages which preserve the determined segmental height and lordosis.
Neurosurgical Review, 2005
Multilevel discectomy and inter-vertebral body fusion combined with anterior plate-screw fixation... more Multilevel discectomy and inter-vertebral body fusion combined with anterior plate-screw fixation is the common procedure in cervical spine surgery. The correct placement of the screws is an important factor for the outcome of these operations. Yet no systematic approach has been undertaken to optimize the geometry of the fixation-plates regarding the position of the screw-perforations. In this study MRI scans of 50 consecutive patients were analyzed regarding the height of each segment (C3-C7), the anterior-posterior diameter of the vertebral body and the distance between the vertebral arteries. Based on this data we developed "Standard Spine Models". Using these models we designed two plates each for single and two-level surgery, and three plates each for three- and four-level surgery. These ten plates do fit the cervical spines of all 50 patients examined in this study. With these plates the screw-perforations could be positioned efficiently over the bodies of the concerned vertebrae. This should facilitate the selection of a plate and the positioning of the screws. Thus the surgeons might save time and the screws might be positioned more exactly and entirely in the vertebral bodies, ensuring a secure fixation.
Neurosurgical Review, 2008
The dynamic fixation system Dynesys is utilized in the last 10 years for treatment of degenerativ... more The dynamic fixation system Dynesys is utilized in the last 10 years for treatment of degenerative segmental disease of the lumbar spine. Dynesys is a semi-rigid fixation system that allows minimal lengthening and shortening between two segmental pedicle screws as opposed to a rigid metal bar. Thus, the system is regarded to maintain stability and near physiological motion patterns of the lumbar spine. The theoretical advantage of this system is to stabilize the treated segment and to prevent adjacent segment degeneration. The goal of this prospective trial was to evaluate clinical, radiographic, and computed tomography (CT) scan outcomes in 54 consecutive cases. Postoperative complications are discussed in detail. Forty cases were recruited with a mean follow-up of 16 months (range, 12 to 37). Postoperative pain scores (Hannover Activities of Daily Living Questionnaire and VAS for back and leg pain) improved in 29 cases (73%) and was best when dynamic fusion was combined with nerve root decompression. Outcome data were not superior to conventional rigid fusion systems and had a considerable number of complications requiring revision surgery in 27.5% of cases.
Neurosurgery, 1997
The goals of the study were to investigate the value of intraoperative electrically evoked nerve ... more The goals of the study were to investigate the value of intraoperative electrically evoked nerve action potentials (NAPs) in the surgical treatment of traumatic peripheral nerve injuries (nerve lesions in continuity). Sixty-four patients with 76 traumatic nerve lesions in continuity were investigated intraoperatively by stimulating and recording NAP from the whole nerve across the suspected lesion site. Among the 76 nerves (nerve lesions) were 43 with incomplete and 33 with complete loss of function. In cases (nerves) with complete loss of function (n = 33), the surgical procedure (external neurolysis, internal neurolysis, or nerve repair) was performed according to the microscopic aspect of the nerve and the result of the intraoperative electrophysiological testing. In cases (nerves) with incomplete loss of function (n = 43), the surgical procedure was performed solely according to the microscopic aspect of the nerve and independently from the result of the intraoperative electrophysiological testing. Of 43 nerves with incomplete loss of function, we were able to record reproducible NAPs in 41 (95%) across the lesion site, thus demonstrating a high reliability of the method. Of 33 nerves with complete loss of function, a reproducible NAP could be recorded only in 3. Assuming an axonotmetic lesion in regeneration, we did nothing else on the nerve with excellent clinical results (full recovery). Of the remaining nerves with no NAP, 24 showed a caliber shift of the nerve (in 20 cases a thickening of the nerve, suggesting a neuroma in continuity). A grafting procedure was performed, and the histological evaluation revealed a neurotmetic lesion. However, in six patients with no NAP, there was no clear caliber shift of the nerve. The epineurium was opened and an internal neurolysis performed showing fascicles in continuity. Three patients had good and three had partial (but useful) recovery. In nerve lesions in continuity with complete loss of nerve function, intraoperative NAPs are able to detect axonotmetic lesions in regeneration. Thus, unnecessary further surgical procedures can be avoided. On the other end of the spectrum, no recordable NAP together with a caliber shift of the nerve (suggesting a neuroma in continuity) may facilitate the surgeon's decision for a grafting procedure without a time-consuming internal neurolysis. But there is also evidence from our data that not every nerve lesion in continuity without a NAP needs to be grafted.
Der Nervenarzt, 1999
ABSTRACT
Spine, Jan 15, 2015
This is a prospective, multicenter cohort study including 8 medical centers in the metropolitan a... more This is a prospective, multicenter cohort study including 8 medical centers in the metropolitan area of the Canton Zurich, Switzerland. To examine whether outcome and quality of life might improve after decompression surgery for degenerative lumbar spinal stenosis (DLSS) even in patients older than 80 years and to compare data with a younger patient population from our own patient collective. Lumbar decompression surgery without fusion has been shown to improve quality of life in lumbar spinal canal stenosis. In the population older than 80 years, treatment recommendations for DLSS show conflicting results. Eight centers in the metropolitan area of Zurich, Switzerland agreed on the classification of DLSS, surgical principles, and follow-up protocols. Patients were followed from baseline, at 6 months, and 12 months. Baseline characteristics were analyzed with 5 different questionnaires "Spinal Stenosis Measure, Feeling Thermometer, Numeric Rating Scale, 5D-3L, and Roland and Mor...
Neurosurgical review, 2009
In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage s... more In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage subsidence and segmental kyphosis seen. The aim of the present study is to assess whether the cage design influences the extent of correction loss during follow-up. Sixty patients with single-level cervical disc herniation were randomly treated with two different cervical inter-body cages (group 1: Solis cage, Stryker Company and group 2: Shell cage, AMT Company). Clinical and radiological follow-up was done before and after surgery, 3 and 6 months post-surgery. Clinical follow-up was done with the help of Odom's criteria. Both groups were similar in the baseline parameters (age, sex, treated level). Statistically, the subsidence was significantly higher at 3 and 6-month follow-ups in group 1 than in group 2, however, clinical results showed no significant differences. In 67%, subsidence was seen in the anterior lower aspect of the treated segment. Segmental kyphosis was seen in seven...
Cancer, Jan 18, 2016
A population-based analysis of patients with glioma diagnosed between 1980 and 1994 in the Canton... more A population-based analysis of patients with glioma diagnosed between 1980 and 1994 in the Canton of Zurich in Switzerland confirmed the overall poor prognosis of glioblastoma. To explore changes in outcome, registry data were reevaluated for patients diagnosed between 2005 and 2009. Patients with glioblastoma who were diagnosed between 2005 and 2009 were identified by the Zurich and Zug Cancer Registry. The prognostic significance of epidemiological and clinical data, isocitrate dehydrogenase 1 (IDH1)(R132H) mutation status, and O6 methylguanine DNA methyltransferase (MGMT) promoter methylation status was analyzed using the Kaplan-Meier method and the Cox proportional hazards model. A total of 264 patients with glioblastoma were identified, for an annual incidence of 3.9 compared with the previous incidence of 3.7. The mean age of the patients at the time of diagnosis was 59.5 years in the current cohort compared with 61.3 years previously. The overall survival (OS) rate was 46.4% ...
Klinische Neurophysiologie
Zentralblatt für Neurochirurgie
Many attempts have been made in the past to find predictive factors concerning patients operated ... more Many attempts have been made in the past to find predictive factors concerning patients operated on because of ulnar nerve entrapment at the elbow. The factors most frequently discussed in the literature are the patient's age, the importance of the preoperative neurological deficit, the duration of symptoms, accompanying diseases as diabetes mellitus or alcoholism and preoperative electrophysiological findings (EMG and conduction velocity measurements). With the exception of the electrophysiological findings, which uniformly are considered to be without predictive value, all other factors mentioned above are discussed controversly. In 1972 Kline and Nulsen [12] have shown, that intraoperatively evoked nerve action potentials across a traumatic nerve lesion can provide information about nerve regeneration. This information helps to choose the appropriate surgical procedure namely either neurolysis or neuroma resection and grafting. However there are no reports dealing with this method in nerve entrapment syndromes. We present the results of 17 patients with ulnar nerve entrapment at the elbow. They were operated on in our hospital between 1989 and 1992 by simple decompression or by anterior transposition of the nerve. In each of them we tried to record electrically evoked nerve action potentials intraoperatively and compared preoperative clinical findings with the potentials recorded. Our main interest was to find out, if the potentials have any predictive value regarding the clinical outcome. In 16 of 17 patients we were able to record a reproducable nerve action potential. Amplitudes varied between 3.4 and 140 uV. Conduction velocities of the fastest fibers ranged from 17 to 71 m/s, while potential duration varied between 1.3 to more than 8 ms.(ABSTRACT TRUNCATED AT 250 WORDS)
Acta Physiologica Scandinavica
OBERLE, J., ELAM, M., KARLSSON, T . & WALLIN, B. G. 1988. Temperature-dependent interaction betwe... more OBERLE, J., ELAM, M., KARLSSON, T . & WALLIN, B. G. 1988. Temperature-dependent interaction between vasoconstrictor and vasodilator mechanisms in human skin. Acta Physiol Scand 132, 459-469.
The American journal of physiology
The effects of sympathetic nerve stimulation on vasoconstrictor responses and overflow of norepin... more The effects of sympathetic nerve stimulation on vasoconstrictor responses and overflow of norepinephrine (NE) and neuropeptide Y-like immunoreactivity (NPY-LI) were studied in the dog gracilis muscle and pig spleen in vivo. A continuous regular impulse activity was compared with irregular human sympathetic and regular bursting patterns. During control conditions, stimulation with the irregular activity induced larger peak vasoconstriction than the regular activity at 0.59 Hz, but not at higher frequencies in the muscle, at 0.59 and 2.0 Hz in the spleen. The nerve stimulation-evoked overflow of NE and NPY-LI from the muscle were not influenced by the pattern of stimulation. The overflow of NPY-LI, but not that of NE, from the spleen was enhanced by the irregular activity at 0.59 and 2.0 Hz, and both NPY-LI and NE overflows were enhanced by regular burst activity at 2.0 Hz. After blockade of alpha- and beta-adrenoceptors by phenoxybenzamine and propranolol, respectively, which enhanced nerve stimulation-evoked overflow of both NE and NPY-LI, the NE overflow from the muscle evoked by the irregular activity was slightly larger at 0.59 Hz but smaller at higher frequencies compared with that evoked by regular activity, whereas the detectable overflow of NPY-LI was not largely influenced by the stimulation pattern. In conclusion, both the vasoconstrictor response and the overflow of NPY-LI and NE seem to be influenced by the pattern and frequency of sympathetic nerve stimulation.
Der Nervenarzt
Endoscopic carpal tunnel release is a new technique for treatment of carpal tunnel syndrome. The ... more Endoscopic carpal tunnel release is a new technique for treatment of carpal tunnel syndrome. The benefits of this procedure are a small skin wound with less local pain, the fact that the hand can quickly be used again, and earlier return to work or other activities. We present the preliminary results of the 3-month follow-up of 88 patients out of a prospective study of 100 patients. All patients were operated on using the one-port technique. Six additional decompressions had to be abandoned and open release was performed. Of the patients with pain, 73.6% (68/88) were completely pain-free and in 13.2% (9/68) pain improved in more than 50%. Subjective symptoms like paresthesia and numbness of the hand disappeared completely in 77.2% (64/83). Sensory deficits disappeared in 50% (33/66). Ten of 17 patients with preoperative paresis of the abductor pollicis brevis muscle and 11/14 with paresis of the opponens pollicis muscle had normal motor function 3 months after the operation. The complication rate concerning nerve lesions was 2.3%. The return to work time was 21 days (range 3-49 days). According to clinical symptoms, our preliminary results do not seem to have any benefits compared to the conventional open technique, and the costs for the endoscopic procedure are markedly higher. The complication rate after the learning curve period is approximately the same as open carpal tunnel release.
Zentralblatt für Neurochirurgie
The sural nerve is the most common nerve serving as a donor in an autologeous nerve grafting proc... more The sural nerve is the most common nerve serving as a donor in an autologeous nerve grafting procedure. However, there is a certain risk for the development of painful paraesthesias at the donor site. Patients in whom a short segment of the sural nerve was resected are suspected to have a greater risk. In a retrospective study we investigated the incidence of painful paraesthesias following removal of a segment of the sural nerve for a grafting procedure. The study includes 41 patients, who were followed at least for one year after surgery (mean 30 months). 9 patients (22%) complained of persisting painful paraesthesias at the donor site suggesting a neuroma at the proximal stump of the sural nerve. The comparison of the length of the nerve segment harvested for grafting shows a tendency for patients with shorter segments having a greater risk to develop painful paraesthesias. However, the difference between the two groups was statistically not significant.
Der Nervenarzt
A 27-year-old otherwise healthy male presented with an isolated but complete axillary nerve palsy... more A 27-year-old otherwise healthy male presented with an isolated but complete axillary nerve palsy after excessive squash playing. When repeated electromyographic investigations showed no signs of reinnervation in the deltoid muscle, surgery was performed in order to restore nerve function. Intraoperatively, the nerve showed a short segment of thinning about 2 cm distally the nerve's origin from the posterior fascicle. As intraoperative electrophysiological testing was also negative (no electrically evoked nerve action potentials across the lesion) the suspicious nerve segment was resected and nerve continuity restored by sural grafts. Histologically, no intact nerve structures could be found at the site of the thinning. Most likely the lesion was caused by traction forces. Follow-up studies showed reinnervation of deltoid function over time.
Zentralblatt für Neurochirurgie
Motor distal latency (MDL) is one of the most important parameters in the electrodiagnosis of car... more Motor distal latency (MDL) is one of the most important parameters in the electrodiagnosis of carpal tunnel syndrome (CTS). In a retrospective study of 1816 open surgical decompressions for CTS, a total of 612 postoperative motor nerve conduction measurements on 485 hands could be evaluated. In patients with good or satisfactory results after carpal tunnel release, an average improvement of MDL of 1.0 ms after 9-13 days, and of 2.2 ms after 1 year and longer was found. The individual motor nerve conduction improvement was in close correlation with the extent of preoperative prolongation of the MDL. Whereas relief of symptoms can be noted almost immediately, prolonged latencies often do not return to normal, even when the study is done a year later. Of the 10 patients with persisting symptoms, four had a new postoperative impairment of MDL, and also four had a marked improvement, whereas it remained unchanged in two. Patients with severe recurrent CTS presented in 11 out of 31 cases ...
Praxis, Jan 20, 2012
We report the case of a 30-year-old female patient who underwent unilateral transverse sinus sten... more We report the case of a 30-year-old female patient who underwent unilateral transverse sinus stenosis stenting due to a newly diagnosed idiopathic intracranial hypertension (Pseudotumor cerebri) with symptoms of papilledema, decreased visual acuity and headache. Resolution of the symptoms and improvement of magnetic resonance and ophthalmiologic findings could be documented.
Spine, 2008
Prospective controlled clinical study. The aim of this prospective nonrandomized study is to eval... more Prospective controlled clinical study. The aim of this prospective nonrandomized study is to evaluate the recurrence rate and the clinical outcome of patients undergoing sole sequestrectomy and compare them with a standard treatment group. While performing microsurgical disc excision, extruded disc fragments and loosened or degenerated parts of the nucleus are removed. It is controversial whether this strategy is always necessary. Within the literature, there is only little information about the results of exclusive sequestrectomy. Criteria for performing a sole sequestrectomy were a nonbulging disc and only small or medium perforations within the fibrous ring. According to these criteria, the authors recruited 90 patients for the sequestrectomy group. The control group was operated in standard microsurgical manner during the same time, including 84 patients. A detailed analysis of the actual pain status, the functional capacity (Hannover Activities of Daily Living Questionnaire, FFbH) and eventually additional spinal operations during the follow-up of 2 years was performed. Mean Funktionsfragebogen Hannover (FFbH) score at the follow-up was 76% in the sequestrectomy group and 77.6% in the control group. This difference is statistically not significant. There were 2 recurrences in the sequestrectomy group at the same level and 1 postoperative instability requiring a fusion procedure. In the control group, there were 2 recurrences and 1 secondary lateral spinal stenosis that led to reoperations. The competence of the fibrous ring influenced significantly the success of a simple sequestrectomy. The sole sequestrectomy group revealed similar results compared with the standard microdiscectomy group. There is a comparable low number of recurrences in both groups. This is probably caused by the consequent selection of patients for sequestrectomy according to well-defined criteria.
Neurosurgical Review, 2009
In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage s... more In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage subsidence and segmental kyphosis seen. The aim of the present study is to assess whether the cage design influences the extent of correction loss during follow-up. Sixty patients with single-level cervical disc herniation were randomly treated with two different cervical inter-body cages (group 1: Solis cage, Stryker Company and group 2: Shell cage, AMT Company). Clinical and radiological follow-up was done before and after surgery, 3 and 6 months post-surgery. Clinical follow-up was done with the help of Odom's criteria. Both groups were similar in the baseline parameters (age, sex, treated level). Statistically, the subsidence was significantly higher at 3 and 6-month follow-ups in group 1 than in group 2, however, clinical results showed no significant differences. In 67%, subsidence was seen in the anterior lower aspect of the treated segment. Segmental kyphosis was seen in seven patients of group 1 and two patients of group 2. A significant correlation is found between Odom's criteria and subsidence. Although there was no significant difference in a short-term clinical result between the two treatment groups, we recommend the use of cages which preserve the determined segmental height and lordosis.
Neurosurgical Review, 2005
Multilevel discectomy and inter-vertebral body fusion combined with anterior plate-screw fixation... more Multilevel discectomy and inter-vertebral body fusion combined with anterior plate-screw fixation is the common procedure in cervical spine surgery. The correct placement of the screws is an important factor for the outcome of these operations. Yet no systematic approach has been undertaken to optimize the geometry of the fixation-plates regarding the position of the screw-perforations. In this study MRI scans of 50 consecutive patients were analyzed regarding the height of each segment (C3-C7), the anterior-posterior diameter of the vertebral body and the distance between the vertebral arteries. Based on this data we developed "Standard Spine Models". Using these models we designed two plates each for single and two-level surgery, and three plates each for three- and four-level surgery. These ten plates do fit the cervical spines of all 50 patients examined in this study. With these plates the screw-perforations could be positioned efficiently over the bodies of the concerned vertebrae. This should facilitate the selection of a plate and the positioning of the screws. Thus the surgeons might save time and the screws might be positioned more exactly and entirely in the vertebral bodies, ensuring a secure fixation.
Neurosurgical Review, 2008
The dynamic fixation system Dynesys is utilized in the last 10 years for treatment of degenerativ... more The dynamic fixation system Dynesys is utilized in the last 10 years for treatment of degenerative segmental disease of the lumbar spine. Dynesys is a semi-rigid fixation system that allows minimal lengthening and shortening between two segmental pedicle screws as opposed to a rigid metal bar. Thus, the system is regarded to maintain stability and near physiological motion patterns of the lumbar spine. The theoretical advantage of this system is to stabilize the treated segment and to prevent adjacent segment degeneration. The goal of this prospective trial was to evaluate clinical, radiographic, and computed tomography (CT) scan outcomes in 54 consecutive cases. Postoperative complications are discussed in detail. Forty cases were recruited with a mean follow-up of 16 months (range, 12 to 37). Postoperative pain scores (Hannover Activities of Daily Living Questionnaire and VAS for back and leg pain) improved in 29 cases (73%) and was best when dynamic fusion was combined with nerve root decompression. Outcome data were not superior to conventional rigid fusion systems and had a considerable number of complications requiring revision surgery in 27.5% of cases.
Neurosurgery, 1997
The goals of the study were to investigate the value of intraoperative electrically evoked nerve ... more The goals of the study were to investigate the value of intraoperative electrically evoked nerve action potentials (NAPs) in the surgical treatment of traumatic peripheral nerve injuries (nerve lesions in continuity). Sixty-four patients with 76 traumatic nerve lesions in continuity were investigated intraoperatively by stimulating and recording NAP from the whole nerve across the suspected lesion site. Among the 76 nerves (nerve lesions) were 43 with incomplete and 33 with complete loss of function. In cases (nerves) with complete loss of function (n = 33), the surgical procedure (external neurolysis, internal neurolysis, or nerve repair) was performed according to the microscopic aspect of the nerve and the result of the intraoperative electrophysiological testing. In cases (nerves) with incomplete loss of function (n = 43), the surgical procedure was performed solely according to the microscopic aspect of the nerve and independently from the result of the intraoperative electrophysiological testing. Of 43 nerves with incomplete loss of function, we were able to record reproducible NAPs in 41 (95%) across the lesion site, thus demonstrating a high reliability of the method. Of 33 nerves with complete loss of function, a reproducible NAP could be recorded only in 3. Assuming an axonotmetic lesion in regeneration, we did nothing else on the nerve with excellent clinical results (full recovery). Of the remaining nerves with no NAP, 24 showed a caliber shift of the nerve (in 20 cases a thickening of the nerve, suggesting a neuroma in continuity). A grafting procedure was performed, and the histological evaluation revealed a neurotmetic lesion. However, in six patients with no NAP, there was no clear caliber shift of the nerve. The epineurium was opened and an internal neurolysis performed showing fascicles in continuity. Three patients had good and three had partial (but useful) recovery. In nerve lesions in continuity with complete loss of nerve function, intraoperative NAPs are able to detect axonotmetic lesions in regeneration. Thus, unnecessary further surgical procedures can be avoided. On the other end of the spectrum, no recordable NAP together with a caliber shift of the nerve (suggesting a neuroma in continuity) may facilitate the surgeon's decision for a grafting procedure without a time-consuming internal neurolysis. But there is also evidence from our data that not every nerve lesion in continuity without a NAP needs to be grafted.
Der Nervenarzt, 1999
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