Jörg Klekamp

Surgical results of 100 intramedullary tumors in relation to accompanying syringomyelia.

During the period from 1977 to August 1992, 100 intramedullary tumors in 94 patients were operated on in the Department of Neurosurgery at the Nordstadt Hospital in Hannover, Germany. Of these, 45% presented with associated syringes. A syrinx was more likely to be found above (49%) than below (11%) the tumor level. In 40%, a syrinx could be identified above and below the tumor level. Ependymomas and hemangioblastomas were the most common tumor types to be associated with syringes. Astrocytomas tended to demonstrate syringes less often. Regardless of histology, the higher the spinal level, the more likely a syrinx was encountered. In general, the presence of an associated syrinx favored the resectability of the tumor, because it indicated a displacing rather than an infiltrating tumor. Patients with syringomyelia tended to recover from surgery sooner. However, surgical results and long-term prognosis were not influenced significantly by an associated syrinx. The most important factor determining long-term outcome was the preoperative level of neurological function. We propose that factors independent of the tumor, disturbances of cerebrospinal fluid and extracellular fluid flow in particular, have major roles in the pathogenesis of syrinx formation associated with intramedullary tumors.

Surgical results for spinal meningiomas

We report on 94 spinal meningiomas in 88 patients operated between September 1977 and August 1994 which were followed for up to 13 years (mean 24 +/- 35 months). Complete tumour resection led to postoperative improvement of every preoperative deficit or symptom. En plaque, recurrent, anterior, and low thoracic or lumbar meningiomas were likely to be resected incompletely. Partial tumour removal, arachnoid scarring, primary dural suture, recurrent meningiomas, and male sex were independent factors predisposing to clinical recurrence. Cauterization instead of resection of the tumor matrix was not associated with a higher recurrence rate.

Surgical results for meningiomas of the craniocervical junction.

OBJECTIVE We have undertaken a retrospective analysis of 38 patients who were operated on for 40 meningiomas of the craniocervical junction between September 1977 and August 1995 to determine which factors influenced resectability, complications, and postoperative outcomes. METHODS Radiological examinations, clinical data, and operation notes were evaluated, and additional follow-up information was obtained from outpatient examinations, telephone calls, and questionnaires. RESULTS Four groups could be distinguished according to dural attachment as follows: 1) 15 spinocranial meningiomas originated from the spinal canal and extended intracranially; 25 craniocervical meningiomas of intracranial origin were divided into 2) meningiomas of the lower clivus (10 patients with 11 tumors), 3) lateral meningiomas (11 patients with 12 tumors), and 4) posterior meningiomas (2 patients). Standard midline or lateral suboccipital approaches with opening of the foramen magnum and laminectomy of the involved cervical segments were sufficient for the great majority of tumors. In seven instances only, drilling the posterior third of an occipital condyle was needed. Twelve of 15 spinocranial meningiomas and 13 of 25 craniocervical meningiomas could be removed totally. One patient underwent ventriculoperitoneal shunting only. With a rate of 63% of totally removed and 30% of subtotally removed meningiomas in this region, we observed clinical recurrences for two patients only. Complications were encountered in 30% of patients, predominantly with recurrent and/or infiltrative or en plaque meningiomas. Whereas motor weakness and gait ataxia tended to improve postoperatively, cranial nerve deficits usually remained unaltered. CONCLUSION The relationship of the tumor to neighboring structures, i.e., the vertebral artery in particular, determines its resectability. We recommend using extreme caution with recurrent or en plaque meningiomas and tumors associated with extensive arachnoid scarring.

Surgery of spinal nerve sheath tumors with special reference to neurofibromatosis.

OBJECTIVE We conducted a retrospective study of 87 patients with spinal nerve sheath tumors to determine the overall clinical outcome and specific features in 20 patients affected with neurofibromatosis Types 1 and 2 (NF-1 and NF-2, respectively). METHODS Case records, operation notes, outpatient files, and radiological examinations were analyzed for all patients treated between September 1977 and August 1994. Additional follow-up data were obtained using outpatient examinations, questionnaires, and telephone calls. RESULTS During the study period, 128 spinal neuromas (i.e., schwannomas) and 6 neurofibromas in 87 patients were treated. Fifty-seven neuromas were associated with NF-2 in 17 patients and six neurofibromas with NF-1 in 3 patients. Patients with NF-2 and symptomatic neuromas presented with more severe neurological deficits compared to patients without NF-2. Eighty-six percent of the neuromas were removed completely. On average, most preoperative deficits or symptoms improved in patients without NF-2, whereas neurological symptoms remained unchanged in patients with NF-2. Multiple regression analysis revealed that partial removal, surgery of a recurrent tumor, NF-2, and old age predisposed for tumor recurrence. No increased risk of recurrence was observed for patients with NF-1. For patients without NF-2, we observed overall recurrence rates of 10.7% after 5 years and 28.2% after 10 and 15 years, respectively, as determined by Kaplan-Meier analysis. For NF-2, the recurrence rate at 5 years was 39.2%, and all tumors had recurred by 9 years. CONCLUSION Spinal nerve sheath tumors carry an excellent prognosis in patients with NF-1 and in patients without neurofibromatosis. Symptomatic neuromas occurring in association with NF-2 present with more severe neurological deficits, demonstrate little postoperative improvement, and have a very high recurrence rate.

Surgical Treatment of Chiari I Malformation-Analysis of Intraoperative Findings, Complications, and Outcome for 371 Foramen Magnum Decompressions

BACKGROUND Foramen magnum decompression is widely accepted as the treatment of choice for Chiari I malformation. However, important surgical details of the procedure are controversial. OBJECTIVE This study analyzes 371 decompressions focusing on intraoperative findings, analysis of complications, and long-term outcomes. METHODS Among 644 patients between 1985 and 2010, 359 patients underwent 371 decompressions. Surgery for symptomatic patients consisted of suboccipital craniectomy, C1 laminectomy, arachnoid dissection, and duraplasty. Short-term results were determined after 3 months; long-term outcomes were evaluated with Kaplan-Meier statistics. RESULTS The mean age was 40 ± 16 years; mean follow-up was 49 ± 56 months; 75.8% demonstrated syringomyelia. The complication rate was 21.8% with permanent surgical morbidity of 3.2% and surgical mortality of 1.3%. Of the patients, 73.6% reported improvement after 3 months; 21% were unchanged. Overall, 14.3% demonstrated a neurological deterioration within 5 years and 15.4% within 10 years. The severity of neurological symptoms correlated with the grade of arachnoid pathology. Outcome data correlated with the number of previous decompressions, severity of arachnoid pathology, handling of the arachnoid, type of duraplasty, and surgical experience. First-time decompressions with arachnoid dissection and an alloplastic duraplasty resulted in surgical morbidity for 2.0%, a 0.9% mortality rate, postoperative improvement after 3 months for 82%, and neurological recurrence rates of 7% after 5 years and 8.7% after 10 years. CONCLUSION Arachnoid pathology in Chiari I malformation has an impact on clinical symptoms and postoperative results. Decompressions with arachnoid dissection and an alloplastic duraplasty performed by surgeons experienced with this pathology offer a favorable long-term prognosis.

Disturbances of cerebrospinal fluid flow attributable to arachnoid scarring cause interstitial edema of the cat spinal cord.

OBJECTIVE Spinal arachnoid scarring may be caused by trauma, inflammation, surgery, spinal instability, degenerative diseases, or malformations and may lead to progressive neurological deficits and syringomyelia. We wanted to investigate the effects of focal arachnoid scarring in the cervical spinal canal of cats on pressures in the subarachnoid space and spinal cord tissue, as well as on spinal cord histological features. METHODS Twenty-nine adult cats were used for this study. Nine animals served as control animals, whereas 20 animals received a focal arachnoid scar at C1–C2, which was produced by placement of a kaolin-soaked fibrin sponge on the posterior surface of the spinal cord. After 4 months, pressure recordings above and below the scar, in the subarachnoid space and spinal cord, were performed. Elasticity measurements were performed with small bolus injections. Morphometric analyses of brain and ventricle volumes, sizes of the central canal, and sizes of the perivascular spaces in gray and white matter were also performed. RESULTS No animal developed clinical or neurophysiological evidence of neurological symptoms at any time. In the kaolin-treated group , pressure recordings revealed a significant increase in the subarachnoid pressure at C1, because of the cerebrospinal fluid flow obstruction. Pressure gradients tended to increase at all measuring points. A significant difference was detected between the spinal cord and subarachnoid space at C2, where the intramedullary pressure exceeded the subarachnoid pressure. Elasticity was significantly increased in the spinal cord at C2. Intracranially, no evidence of hydrocephalus was observed. In the spinal cord, perivascular spaces were significantly enlarged in the posterior white matter above the arachnoid scar and in the central gray matter below the area of scarring in the cervical cord. CONCLUSION Arachnoid scarring at C1–C2 produces an interstitial type of edema in the central gray matter below the area of scarring in the cat cervical cord, because of altered cerebrospinal fluid and extracellular fluid flow dynamics. These changes may be interpreted as the initial stage in the development of syringomyelic cavities.

Spontaneous resolution of Chiari I malformation and syringomyelia: case report and review of the literature.

OBJECTIVE AND IMPORTANCE Indications for surgery and the surgical technique of foramen magnum decompression for patients with Chiari I malformation and syringomyelia are controversial issues. This case report supports the view that observation may be adequate for patients without progressive symptoms or with mild clinical symptoms. CLINICAL PRESENTATION A 37-year-old woman presented with a 3-month history of burning dysesthesias and hypesthesia in her right arm. A neurological examination revealed hypesthesia in the right trigeminal distribution. A magnetic resonance imaging scan revealed a Chiari I malformation with syringomyelia between C2 and T2. No hydrocephalus was observed. CLINICAL COURSEBecause the patient’s symptoms regressed spontaneously, surgery was not performed. Thirty-two months after her initial examination, the patient was asymptomatic. A second magnetic resonance imaging scan was obtained, which demonstrated complete spontaneous resolution of the Chiari I malformation and syringomyelia. CONCLUSIONWe attribute the regression of the patient’s symptoms to spontaneous recanalization of cerebrospinal fluid pathways at the foramen magnum, which most likely was due to rupture of the arachnoid membranes that had obstructed cerebrospinal fluid flow.

Treatment of intramedullary tumors: analysis of surgical morbidity and long-term results

OBJECT Surgery of intramedullary tumors is established as the treatment of choice for these challenging lesions. This study presents a detailed analysis of risk factors for surgical morbidity and data on long-term results for intramedullary tumors. METHODS Among 1317 patients with tumors of the spinal canal treated between 1980 and 2012, 278 patients with intramedullary tumors are presented. A total of 225 of these patients underwent 246 operations for treatment of 250 tumors. The mean patient age was 41 ± 17 years (range 3 weeks to 83 years). Patients underwent follow-up through outpatient visits and questionnaires with a mean follow-up of 41 ± 53 months. Tumors were subdivided into 3 groups: displacing tumors (Type A, n = 162), infiltrating tumors (Type B, n = 80), and nonproliferating tumors (Type C, n = 8). A gross-total resection (GTR) was attempted for every tumor except for Type C lipomas. Participating surgeons were divided into 3 groups according to the number of operations they performed. Short-term results were determined for individual symptoms and the modified McCormick Scale, whereas tumor recurrence rates were calculated with Kaplan-Meier statistics. RESULTS Overall, 83.3% of Type A tumors underwent GTR compared with 22.5% of Type B and none in Type C. Gross-total resection rates increased throughout the study period and correlated significantly with surgical experience. A worsened neurological state after surgery was seen in 61% of patients. This deterioration was transient in 41.5% and was a common observation after GTR. Permanent morbidity (19.5%) was lowest after GTR and correlated significantly with surgical experience and the preoperative neurological state. Further analysis showed that patients with tumors of thoracic levels, tumor hemorrhages, and malignant and recurrent tumors were at a higher risk for permanent morbidity. In the long term, tumor recurrence rates for ependymomas and benign astrocytomas correlated significantly with the amount of resection. Long-term morbidity affected 3.7% with a postoperative myelopathy related to cord tethering at the level of surgery and 21.9% in form of neuropathic pain syndromes. The rate of postsurgical cord tethering could be lowered significantly by using pia sutures after tumor resection. Neuropathic pain syndromes were more common after surgery for tumors with associated syringomyelia or those located in the cervical cord. CONCLUSIONS Intramedullary tumors should be surgically treated as soon as neurological symptoms appear. Gross-total resection is possible for the majority of benign pathologies. Cervical tumors are associated with higher GTR and lower permanent morbidity rates compared with thoracic tumors. Surgery on intramedullary tumors should be performed by neurosurgeons who deal with these lesions on a regular basis as considerable experience is required to achieve high GTR rates and to limit rates of permanent morbidity.

Tethered cord syndrome in adults

OBJECT The treatment of tethered cord syndromes in adults is discussed regarding the natural history and surgical indications. The author analyzes data obtained in patients who were diagnosed with a tethered cord in adulthood and either underwent surgical or conservative therapy between 1991 and 2009. METHODS Since 1991, data obtained in 2515 patients with spinal cord pathologies were entered into the spinal cord database, and prospective follow-up was performed through outpatient visits and questionnaires. Of the 2515 patients, 85 adults with a tethered cord syndrome formed the basis of this study. The tethering effect was caused either by a split cord malformation, a thick filum terminale, a conus medullaris lipoma with extradural extension, or various combinations of these mechanisms. The mean age of the patients was 46 ± 13 years (range 23-74 years) and the mean follow-up duration was 61 ± 62 months. Two groups were distinguished based on the absence (Group A, 43 patients) or presence (Group B, 42 patients) of an associated lipoma or dysraphic cyst (that is, dermoid, epidermoid, or neurenteric cyst). Surgery was recommended for patients with symptoms only. Short-term results were determined within 3 months of surgery, whereas long-term outcomes (clinical recurrences) were evaluated using Kaplan-Meier statistics. RESULTS For all patients, pain was the most common major complaint. Severe neurological deficits were rare. In Group A, 20 of 43 patients underwent surgery, whereas in Group B 23 of 42 patients underwent surgery. Among individuals who did not undergo surgery, 17 patients refused surgery and 25 patients underwent recommended conservative treatment. Short-term postoperative results indicated a significant improvement of pain and a stabilization of neurological symptoms. Long-term results showed a good prognosis in patients in whom first-time (that is, nonrevision) surgery achieved successful untethering, with a 10-year rate of neurological stabilization in 89% of Group A and a 10-year rate of neurological stabilization in 81% of Group B patients. The benefit of secondary operations in Group B was limited, with eventual clinical deterioration occurring in all patients within 10 years. For patients treated conservatively, follow-up information could be obtained in 33 of 42 patients. Twenty-eight patients remained in stable clinical condition. Only 5 of the conservatively treated patients experienced clinical deterioration over time; in 4 of these individuals with deterioration, surgery had been recommended but was refused by the patient. The clinical recurrence rate in all conservatively treated patients was 21% after 10 years. With a recommendation for surgery this figure rose to 47% within 5 years. CONCLUSIONS Surgery in adult patients with a tethered cord syndrome should be reserved for those with symptoms. In surgically treated patients, pain relief can often be achieved, and long-term neurological stabilization tends to persist more often than it does in conservatively treated patients. A conservative approach is warranted, however, in adult patients without neurological deficits. Revision surgery in patients with complex dysraphic lesions should be performed in exceptional cases only.

Occult dysraphism in adulthood: clinical course and management

We present a series of 23 patients with dysraphic malformations and adult onset of symptoms (4 meningoceles, 19 spinal hamartomas). Mean age at presentation was 39±21 years (range 23–67 years). Patients were followed up for a mean period of 19 months (range 0.5–68 months). Only patients with progressive neurological disease were operated on (3 meningoceles and 16 spinal hamartomas). The remaining patients were treated conservatively and continue to be observed clinically. Two of three patients operated for meningoceles improved without recurrence of symptoms. Patients with spinal hamartomas could be divided into two groups according to their main symptom: paraparesis (group A, n = 8) or pain (group B, n = 11). Malformations in group B were typically associated with a tethered cord and tended to be more complex than in group A. The majority of patients in group A showed better long-term results than patients in group B, due to their considerably lower rate of recurrence.