H. A. M. van Alphen

Bio: H. A. M. van Alphen is an academic researcher from VU University Amsterdam. The author has contributed to research in topics: Discectomy & Immunoperoxidase. The author has an hindex of 6, co-authored 11 publications receiving 604 citations.

Operative treatment of spontaneous spinal epidural hematomas : a study of the factors determining postoperative outcome

Abstract: OBJECTIVE: We clarify the factors affecting postoperative outcomes in patients who have suffered spontaneous spinal epidural hematomas. METHODS: We review 330 cases of spontaneous spinal epidural hematomas from the international literature and three unpublished cases of our own. Attention was focused on sex, age, medical history, mortality, size and position of the hematoma, vertebral level of the hematoma, preoperative neurological condition, operative interval, and postoperative result. RESULTS: Sex, age, and size and position of the hematoma did not correlate with postoperative outcome. Mortality correlated highly with cervical or cervicothoracic hematomas, especially in patients with cardiovascular disease and those undergoing anticoagulant therapy. Incomplete preoperative sensorimotor deficit correlated highly with favorable outcomes (P < 0.0005), and recovery was significantly better when decompression was performed in < or = 36 hours in patients with complete sensorimotor loss (P < 0.05) and in < or = 48 hours in patients with incomplete sensorimotor deficit (P < 0.005). CONCLUSION: The critical factors for recovery after spontaneous spinal epidural hematoma are the level of preoperative neurological deficit and the operative interval. The vertebral level of the hematoma did not correlate with postoperative results, which suggests that local compression, rather than vascular obstruction, is the main factor in producing neurological deficit.

Morphology of the human internal vertebral venous plexus: A cadaver study after intravenous araldite CY 221 injection

Abstract: Reviewing the literature on the vascular anatomy of the spinal epidural space, it appeared that the knowledge of the internal vertebral venous plexus is limited. Injection studies of the entire internal vertebral venous plexus after application of modern techniques, to the best of our knowledge, have never been performed. Based on the clinical importance of these structures, it was decided to study the human vertebral venous system after Araldite CY 221 injection, in order to update the morphological characteristics of the internal vertebral venous system. The vertebral venous systems of ten fresh human cadavers, between 64 and 93 years of age, were injected with Araldite CY 221 mixture. All cadavers were dissected and the posterior and anterior internal vertebral venous plexuses were studied in detail. The anterior part of the internal vertebral venous plexus is fairly constant. On the contrary, the posterior internal vertebral venous plexus showed a striking segmental and interindividual variability. In the thoracic area, two types of traversing veins are observed. Both types show a somewhat symmetrical "inversed V" configuration. No anatomical valves were observed. Nevertheless, anterograde flushing (via the femoral veins) of the vertebral venous system appeared to proceed much faster than retrograde flushing (via the superior vena cava). The classical picture of the internal vertebral venous plexus appears a simplification of the actual situation. Especially in the posterior part, segmental and interindividual differences are prominent. The preferential direction of the flow during flushing suggests the presence of functional valves, which are probably located in the thoracic part of the posterior internal vertebral venous plexus, resulting from the typical shape of the veins in this area. This might explain the difficulties with imaging of the posterior part of the internal vertebral venous plexus in vitro as well as in vivo. Further study is needed to determine whether the configuration of the posterior internal vertebral venous plexus in younger individuals is different, compared with the presently studied aged subjects.

Chemonucleolysis versus discectomy: a randomized multicenter trial.

Abstract: A randomized clinical trial was carried out to compare the results of open discectomy with those of chemonucleolysis in 151 patients suffering from a disc herniation at L4-5 or L5-S1. All patients fulfilled strict entry criteria; 78 patients underwent open discectomy and 73 were subjected to chemonucleolysis. An increase in radicular pain immediately after treatment was encountered in 16 patients (22%) in the chemonucleolysis group, as compared to none in the discectomy group. The efficacy of discectomy appeared to be definitely superior to that of chemonucleolysis. Within a follow-up period of 1 year, 18 patients (25%) required open discectomy following failed chemonucleolysis; two patients (3%) in the discectomy group needed a second operation. Open discectomy following previous chemonucleolysis was successful in only 44% of cases. Comparison of the final results of the two modes of treatment 12 months after the last intervention (including second treatment) did not reveal any significant differences. The duration of the preoperative symptoms, the level of disc herniation, and the leakage of contrast medium out of the disc appeared to be of no relevance to the final outcome. The complication rates in both treatment groups were low.

Meningioma with conspicuous plasma cell components. A histopathological and immunohistochemical study.

Abstract: A peculiar type of meningioma with conspicious plasma-cell components is described. Immunohistochemical analysis revealed the polyclonal nature of the plasma cell population. Consequently, the plasma cells could not be regarded as a neoplastic component.

The value of continuous intra-operative EEG monitoring during carotid endarterectomy.

Abstract: In a retrospective study, an evaluation was made of the intraoperative EEG findings and clinical results of 100 consecutive carotid endarterectomies carried out in 90 patients over the period 1977 to 1983. There was no operation-associated mortality; the peri-operative morbidity was 5%. All operations were performed maintaining the systemic blood pressure some 20% above the patients normal value. No interval shunt was used. The surgical policy was not influenced by EEG findings in any of the procedures. There was no relationship between carotid-clamping time and intra-operative EEG changes, nor was there a relationship between EEG changes and clinical outcome. It is most likely that neurological deficit following carotid endarterectomy, if operation is performed during elevated systemic blood pressure, is not due to haemodynamic disturbances, as a consequence of critical reduction of cerebral blood flow during internal carotid artery clamping, but to micro-embolism. From this assumption, it can be concluded that peri-operative complications of carotid endarterectomy cannot be reduced by intra-operative EEG monitoring.

The new WHO classification of brain tumours.

Abstract: The new edition of the World Health Organization (WHO) book on 'Histological Typing of Tumours of the Central Nervous System' reflects the progress in brain tumour classification which has been achieved since publication of the first edition in 1979. Several new tumour entities have been added, including the pleomorphic xanthoastrocytoma, central neurocytoma, the infantile desmoplastic astrocytoma/ganglioglioma, and the dysembryoplastic neuroepithelial tumour. The list of histological variants has also been expanded. In line with recent morphological and molecular data on glioma progression, the glioblastoma is now grouped together with astrocytic tumours. The classification of childhood tumours has been largely retained, the diagnosis primitive neuroectodermal tumour (PNET) only being recommended as a generic term for cerebellar medulloblastomas and neoplasms that are histologically indistinguishable from medulloblastoma but located in the CNS at sites other than the cerebellum. The WHO grading scheme was revised and adapted to new entities but its use, as before, remains optional.

Spinal hematoma: a literature survey with meta-analysis of 613 patients

Abstract: Spinal hematoma has been described in autopsies since 1682 and as a clinical diagnosis since 1867. It is a rare and usually severe neurological disorder that, without adequate treatment, often leads to death or permanent neurological deficit. Epidural as well as subdural and subarachnoid hematomas have been investigated. Some cases of subarachnoid spinal hematoma may present with symptoms similar to those of cerebral hemorrhage. The literature offers no reliable estimates of the incidence of spinal hematoma, perhaps due to the rarity of this disorder. In the present work, 613 case studies published between 1826 and 1996 have been evaluated, which represents the largest review on this topic to date. Most cases of spinal hematoma have a multifactorial etiology whose individual components are not all understood in detail. In up to a third of cases (29.7%) of spinal hematoma, no etiological factor can be identified as the cause of the bleeding. Following idiopathic spinal hematoma, cases related to anticoagulant therapy and vascular malformations represent the second and third most common categories. Spinal and epidural anesthetic procedures in combination with anticoagulant therapy represent the fifth most common etiological group and spinal and epidural anesthetic procedures alone represent the tenth most common cause of spinal hematoma. Anticoagulant therapy alone probably does not trigger spinal hemorrhage. It is likely that there must additionally be a "locus minoris resistentiae" together with increased pressure in the interior vertebral venous plexus in order to cause spinal hemorrhage. The latter two factors are thought to be sufficient to cause spontaneous spinal hematoma. Physicians should require strict indications for the use of spinal anesthetic procedures in patients receiving anticoagulant therapy, even if the incidence of spinal hematoma following this combination is low. If spinal anesthetic procedures are performed before, during, or after anticoagulant treatment, close monitoring of the neurological status of the patient is warranted. Time limits regarding the use of anticoagulant therapy before or after spinal anesthetic procedures have been proposed and are thought to be safe for patients. Investigation of the coagulation status alone does not necessarily provide an accurate estimate of the risk of hemorrhage. The most important measure for recognizing patients at high risk is a thorough clinical history. Most spinal hematomas are localized dorsally to the spinal cord at the level of the cervicothoracic and thoracolumbar regions. Subarachnoid hematomas can extend along the entire length of the subarachnoid space. Epidural and subdural spinal hematoma present with intense, knife-like pain at the location of the hemorrhage ("coup de poignard") that may be followed in some cases by a pain-free interval of minutes to days, after which there is progressive paralysis below the affected spinal level. Subarachnoid hematoma can be associated with meningitis symptoms, disturbances of consciousness, and epileptic seizures and is often misdiagnosed as cerebral hemorrhage based on these symptoms. Most patients are between 55 and 70 years old. Of all patients with spinal hemorrhage, 63.9% are men. The examination of first choice is magnetic resonance imaging. The treatment of choice is surgical decompression. Of the patients investigated in the present work, 39.6% experienced complete recovery. The less severe the preoperative symptoms are and the more quickly surgical decompression can be performed, the better are the chances for complete recovery. It is therefore essential to recognize the relatively typical clinical presentation of spinal hematoma in a timely manner to allow correct diagnostic and therapeutic measures to be taken to maximize the patient's chance of complete recovery.

Surgery for Low Back Pain: A Review of the Evidence for an American Pain Society Clinical Practice Guideline

Abstract: Study design: Systematic review. Objective: To systematically assess benefits and harms of surgery for nonradicular back pain with common degenerative changes, radiculopathy with herniated lumbar disc, and symptomatic spinal stenosis. Summary of background data: Although back surgery rates continue to increase, there is uncertainty or controversy about utility of back surgery for various conditions. Methods: Electronic database searches on Ovid MEDLINE and the Cochrane databases were conducted through July 2008 to identify randomized controlled trials and systematic reviews of the above therapies. All relevant studies were methodologically assessed by 2 independent reviewers using criteria developed by the Cochrane Back Review Group (for trials) and Oxman (for systematic reviews). A qualitative synthesis of results was performed using methods adapted from the US Preventive Services Task Force. Results: For nonradicular low back pain with common degenerative changes, we found fair evidence that fusion is no better than intensive rehabilitation with a cognitive-behavioral emphasis for improvement in pain or function, but slightly to moderately superior to standard (nonintensive) nonsurgical therapy. Less than half of patients experience optimal outcomes (defined as no more than sporadic pain, slight restriction of function, and occasional analgesics) following fusion. Clinical benefits of instrumented versus noninstrumented fusion are unclear. For radiculopathy with herniated lumbar disc, we found good evidence that standard open discectomy and microdiscectomy are moderately superior to nonsurgical therapy for improvement in pain and function through 2 to 3 months. For symptomatic spinal stenosis with or without degenerative spondylolisthesis, we found good evidence that decompressive surgery is moderately superior to nonsurgical therapy through 1 to 2 years. For both conditions, patients on average experience improvement either with or without surgery, and benefits associated with surgery decrease with long-term follow-up in some trials. Although there is fair evidence that artificial disc replacement is similarly effective compared to fusion for single level degenerative disc disease and that an interspinous spacer device is superior to nonsurgical therapy for 1- or 2-level spinal stenosis with symptoms relieved with forward flexion, insufficient evidence exists to judge long-term benefits or harms. Conclusion: Surgery for radiculopathy with herniated lumbar disc and symptomatic spinal stenosis is associated with short-term benefits compared to nonsurgical therapy, though benefits diminish with long-term follow-up in some trials. For nonradicular back pain with common degenerative changes, fusion is no more effective than intensive rehabilitation, but associated with small to moderate benefits compared to standard nonsurgical therapy.