M. Trummer

A prospective cohort study of close interval computed tomography and magnetic resonance imaging after primary lumbar discectomy: factors associated with recurrent disc herniation and disc height loss.

Study Design. Prospective cohort study. Objective. We performed a prospective cohort study with standardized postoperative lumbar imaging every 3 months for a year then annually to assess the incidence and factors associated with same-level recurrent disc herniation. Summary of Background Data. The true incidence of same-level recurrent disc herniation after lumbar discectomy is unclear. Retrospective studies have reported widely varying incidences between 3% and 18%. Prospective controlled studies are lacking. Methods. A total of 108 patients undergoing first-time lumbar discectomy for refractory radiculopathy were enrolled. Baseline lumbar CT and MRI and standardized clinical data were assessed before surgery, and CT and MRI scans repeated 6 weeks, 3, 6, 9, 12, and 24-months after surgery and at the time of recurrent sciatica. Age, weight, preoperative disc volume, and height, volume of disc removed, and size of anular defect were compared with postoperative disc height loss and recurrent disc herniation using regression analysis. Results. One hundred patients (41 ± 10 years old) were available for 1-year (93%) and 76 (70%) for 2-year follow-up (mean follow-up: 25 ± 12 months). Improvement in all outcome measures was observed by 6 weeks after surgery (P < 0.005). An 18% loss of disc height was observed 3 months after surgery, progressing to 26% by 2 years. Eleven (10.2%) patients experienced recurrent disc herniation requiring revision discectomy a mean 10.5 months after surgery. Subjects with larger anular defects (P = 0.019) and with smaller percentage of disc volume removed (P = 0.028) were associated with an increased risk of recurrent disc herniation. Conversely, those from whom greater disc volumes were removed (P = 0.024) had more progressive disc height loss by 6 months after surgery. Conclusion. Larger anular defects and less disc removal increased the risk of reherniation. Greater volumes of disc removal were associated with accelerated disc height loss. In the setting of larger anular defects or less aggressive disc removal, concern for recurrent herniation should be increased during outpatient follow-up. In this situation effective anular repair may be helpful.

Gamma knife radiosurgery for glomus jugulare tumours.

Summary The aim of this clinical study was to determine the tumour control rate, clinical outcome and complication rate following gamma knife treatment for glomus jugulare tumours. Between May 1992 and May 1998, 13 patients with glomus tumours underwent stereotactic radiosurgical treatment in our department. The age of these patients ranged from 21 to 80 years. The male : female ratio was 2 : 11. Six patients had primary open surgery for partial removal or recurrent growth and subsequent radiosurgical therapy. Radiosurgery was performed as primary treatment in 7 cases. The median tumour volume was 6,4 cm3 (range: 4,6–13,7 cm3). The median marginal dose applied to an average isodose volume of 50% (30–50%) was 13,5 Gy (12–20 Gy). In 10 patients, a total of 48 MRI and CT follow-up scans were available. The remaining three patients have been excluded from the postradiosurgical evaluation since the observation time (t<12 months) was too short or patients were lost to follow up. The median interval from Gamma Knife treatment to the last radiological follow-up was 37,6 months (5–68 months). In 4 patients (40%) decreased tumour volumes were observed and in 6 cases (60%) the tumour size remained unchanged. Neurological follow-up examinations revealed improved clinical status in 5 patients (50%), a stable neurological status in 5 patients (50%) and no complications occurred. According to our preliminary experience Gamma Knife radiosurgery represents an effective treatment option for glomus jugulare tumours.

Preservation of Cranial Nerve Function Following Gamma Knife Radiosurgery for Benign Skull Base Meningiomas: Experience in 121 Patients with Follow-up of 5 to 9.8 Years

INTRODUCTION Microsurgical excision with preservation of juxtaposed neurovascular structures is considered the treatment of choice for skull base meningiomas, but there exists a great controversy regarding surgical resectability, potential risk for subsequent postoperative Cranial Nerve Deficit (CND) and the role of adjuvant or adjunctive treatment options. In this study we evaluated the effect of Gamma Knife Radiosurgery (GKRS) in 121 patients with benign basal meningiomas after a follow-up of 5 to 9.8 years. METHODS Sixty patients had undergone open resections prior to radiosurgical treatment and 61 patients were treated by GKRS alone. Tumour volumes of 0.5 to 89.9 ccm (median 6.8 ccm) received a median marginal dose of 13 Gy (range 7-25 Gy) at the covering 25% to 80% isodose volume curves (median 45%). RESULTS Neuroradiological controls demonstrated decreased tumour size in 73 patients (60.3%), stable meningioma volume in 47 cases (38.9%) and tumour enlargement in one patient (0.8%). Clinically, 54 patients (44.6%) improved and 61 cases (50.4%) remained unchanged. Four patients (3.3%) showed temporary and two patients (1.7%) permanent neurological deterioration (unrelated to tumour or treatment in one patient). Two patients (1.7%) developed radiation induced new or aggravated pre-existent CND (1 transient, 1 permanent) and two patients (1.7%) required further surgical resection. CONCLUSION In our long-term experience, GKRS proved to be an attractive additional and save alternative primary treatment option in selected patients with basal meningiomas. The tumour control rate of 98.3% associated with excellent clinical outcome and low incidence for treatment related CND (1.7%) compares favourably with the reported microsurgical series.

Radiosurgery of Vestibular Schwannomas: A Minimally Invasive Alternative to Microsurgery

Summary¶ From April 1992 till December 1998 stereotactic radiosurgery (Gamma Knife) was applied to 192 patients with vestibular schwannomas. 56 of them had radiosurgery as primary treatment modality and were followed-up for at least 4 years (48–80 months, median 62). Without fatal complications, control of tumour growth was achieved in all but three cases, useful hearing being preserved in more than one half of the patients (62%). The neurological state improved in 30 patients (54%). Irradiation-associated adverse effects (18%) comprised neurological signs (incomplete facial palsy, four cases (two recovered completely), and mild trigeminal neuropathy, three cases, respectively) and morphological changes (three patients) marked by an enlargement of pre-existing cystic components calling for additional surgical treatment: Microsurgical decompression was performed in two cases, the third patient underwent a shunting procedure because of hydrocephalus formation. Based on the present data, radiosurgery represents an effective treatment for vestibular schwannomas associated with an exceptionally low mortality rate and a good quality of life. With respect to the preservation of cranial nerve function, results are comparable to microsurgical resection. A short duration of hospitalization and a quick return to normal activities constitute further advantages and contribute to cost effectiveness in public health care.

Radiosurgery of residual and recurrent vestibular schwannomas.

Summary. Radiosurgery is either a primary or an adjunctive management approach used to treat patients with vestibular schwannomas. We sought to determine outcomes measuring the potential benefits against the neurological risks in patients who underwent radiosurgery after previous microsurgical subtotal resection or recurrence of the tumour after total resection. Gamma Knife radiosurgery was applied as an adjunctive treatment modality for 86 patients with vestibular schwannomas from April 1992 to August 2001. We evaluated the results of 50 patients who had a follow-up of at least 3.5 years (median 75 months, range 42–114 months). In 16 patients a recurrence of disease was observed after previous total resection. The median treatment volume was 3.4 ccm with a median dose to the tumour margin of 13 Gy. Tumour control rate was 96%. Two tumours progressed after adjunctive radiosurgery. Useful hearing (Gardner-Robertson II) (4 patients (8%)) and residual hearing (Gardner-Roberson III) (10 patients (20%)) remained unchanged in all patients, who presented with it before radiosurgery, respectively. Clinical neurological improvement was observed in 24 patients (46%). Adverse effects comprised transient neurological symptoms and signs (incomplete facial palsy, House-Brackman II/III) in five cases (recovered completely), mild trigeminal neuropathy in four cases, and morphological changes displaying rapid enlargement of a pre-existing macrocyst in one patient and tumour growth in another one. No permanent new cranial nerve deficit was observed. Radiosurgery appears to be an effective adjunctive method for growth control of vestibular schwannomas and is associated with both a low mortality rate and a good quality of life. Accordingly, radiosurgery is a rewarding therapeutic approach for the preservation of cranial nerve function in the management of patients with vestibular schwannoma in whom prior microsurgical resection failed.

Lumbar disc herniation mimicking meralgia paresthetica: case report

BACKGROUND Meralgia paresthetica, a syndrome of pain and/or dysesthesia in the anterolateral thigh, is normally caused by an entrapment of the lateral femoral cutaneous nerve (LFCN) at the anterior superior iliac spine. In a few cases compression of the nerve in the retroperitoneum has been reported to mimic meralgia paresthetica. CASE DESCRIPTION A 67-year-old woman presented with a 5-year history of permanent paresthesia in the anterolateral thigh. Motor weakness was not detected. Electromyography showed a neurogenic lesion at the level of L3. Lumbar spine MRI detected a foraminal-extraforaminal disc herniation at L2/L3, which was extirpated via a lateral transmuscular approach. The patient was free of symptoms on the first postoperative day. CONCLUSION In patients with meralgia paresthetica we emphasize a complete radiological investigation of the lumbar spine, including MRI, to exclude radicular compression by a disc herniation or a tumour at the level of L2 or L3.

Prediction parameters of bone flap resorption following cranioplasty with autologous bone

OBJECTIVE The number of patients who need cranioplasty after decompressive craniectomy has increased. In most cases, autologous bone flaps are used for cranioplasty, and there have been reports of the complication of bone flap resorption. Based on these facts, we analysed patients who underwent cranioplasty in our institution to learn about potential risk factors of cranioplasty. METHODS AND RESULTS We performed a retrospective study and analysed 58 patients who underwent cranioplasty between 2006 and 2013. We found that patients with a defect size >120cm(2) whose reimplantation was delayed tended to have a risk of bone flap resorption. CONCLUSION Patients with delayed reimplantation and a defect size >120cm(2) show a tendency of aseptic bone flap resorption. In these cases, a patient-specific implant (PSI) could be the first choice material for this procedure to reduce the rate of this complication.

Protecting facet joints post-lumbar discectomy: Barricaid annular closure device reduces risk of facet degeneration

Lumbar discectomy is an effective treatment for lumbar disc herniation (LDH). Although the majority of patients experience successful outcomes, a significant fraction will experience a recurrence of their back pain due to facet joint degeneration. Facet joint degeneration after discectomy may be the result of excessive nuclear removal, disc space narrowing, and annular injury. This study investigated whether implantation with the Barricaid annular closure device (ACD) during discectomy reduced the rate of facet degeneration. Inclusion criteria were primary lumbar disc herniation failing conservative treatment, Visual Analog Scale (VAS) Leg≥40/100, Oswestry Disability Index (ODI)≥40/100 and defects that were ≤60 mm2 (Barricaid arm only), and patient age 18-75. CT interpretations were collected preoperatively and 12 months post-discectomy. Patients implanted with Barricaid had significantly reduced rates and grades of facet degeneration than patients without Barricaid. Reinforcing the annulus fibrosus with Barricaid during lumbar discectomy may slow the progression of facet joint degeneration.

Endoscopic percutaneous transforaminal treatment for herniated lumbar discs.

Summary. Background: The prevailing percutaneous treatment options for herniated non-contained lumbar discs have not reliably achieved the same good results as the conventional microsurgical techniques. In this study we evaluated clinical outcome and complication rate following endoscopic percutaneous transforaminal treatment of extruded or sequestrated herniated lumbar discs in 122 patients with a follow-up period of more than one year. Method: Between October 1997 and December 2000, 86 male and 36 female patients with a median age of 55 years (range 18 to 89 years) underwent endoscopic treatment for non-contained herniated lumbar discs at our department. Neurological controls were conducted after 4 to 8 weeks routinely and the clinical result was reassessed at a follow-up of 15 to 53 months (median 35 months) according to the Macnab scale and Prolo outcome score. Findings: On follow-up examination, 96 patients were found with permanently ameliorated or normal clinical status following endoscopy alone. The remaining 26 cases with unchanged or only temporarily improved neurological disorders were submitted to conventional microsurgical interventions. Spinal nerve root injury during endoscopic treatment occurred in two patients but no additional neurological deficits or aggravation of pre-existing disorders were observed. Interpretation: Due to the minimal invasivity, the good functional outcome (78.7% clinical amelioration) and the low complication rate (1.6%), this procedure represents an attractive and efficient treatment alternative especially for foraminal and extraforaminal herniated lumbar discs and reduces the indications for open surgery in selected cases.

Die radiochirurgie des Akustikusneurinoms als minimal-invasive Alternative zur Mikrochirurgie

ZusammenfassungVon April 1992 bis Ende Juli 1998 wurden an der Universitätsklinik für Neurochirugie in Graz 1382 Patienten mittels stereotaktischer Radiochirurgie (γ-Knife) behandelt. 181 Patienten hatten Akustikusneurinome; 44 sind nun mindestens 4 Jahre beobachtet worden (48–75, Median 60 Monate). Bei fehlender Mortalität fand sich nur in einem Fall Tumorwachstum. Das präoperativ vorhandene „gebrauchsfähige” Gehör blieb in mehr als der Hälfte der Patienten erhalten (60%); 2 Patienten mit zystischen Anteilen wiesen als Bestrahlungsfolge eine Vergrößerung auf, ein Patient mußte nachoperiert werden; 3 Fazialisparesen und 2 Trigeminusschädigungen traten transient auf, eine Fazialisparese (HBI III) persistierte. Ein Patient entwickelte einen Hydrozephalus und wurde geshuntet. Der neurologische Befund hatte sich bei 23 Patienten (52%) gebessert, 5 Patienten klagten über neu auftretende bzw. verschlechterte Defizite (11%). Die Radiochirurgie ist eine wirkungsvolle alternative Behandlungsform für Akustikusneurinome mit fehlender Mortalität und niedriger Morbidität. Eine 2tägige Krankenhausaufenthaltsdauer und eine sofortige Rückkehr zu den normalen Aktivitäten des täglichen Lebens machen die Behandlung auch hinsichtlich der Kosten vorteilhaft.SummaryFrom April 1992 to July 1998 stereotactic radiosurgery (Gamma Knife) was used to treat 1382 patients; 181 had acoustic neurinomas and were followed up, 44 of them for at least 4 years (48–75 months, median 60). With no mortality control of growth tumor was achieved in all cases but one. It was possible to preserve useful hearing in more than half of the patients (60%). In two patients complications due to the radiation with enlargement of the cystic component were observed. One patient needed additional microsurgical decompression. Three patients suffered transient incomplete facial palsy (one permanent, HBI III), and two patients complained of mild trigeminal neuropathy. One suffered from hydrocephalus and a shunting procedure was necessary. The neurological state improved in 23 patients (52%); five complained of new or worsened deficits. Radiosurgery is an effective alternative treatment for acoustic neurinomas with exceptionally low mortality and morbidity. With respect to preserving cranial nerve function the results are just as good as those of microsurgical resection. Short duration of hospitalization and quick return to normal activities make radiosurgery quite cost effective.