Theoretical considerations on the pathophysiology of normal pressure hydrocephalus (NPH) and NPH-related dementia.

Normal pressure hydrocephalus (NPH) is considered to be an example of reversible dementia although clinical improvement after shunting varies from subject to subject, and recent studies have pointed to a possible link with other dementia. The authors consider that the craniospinal compartment is a partially closed sphere with control device systems represented by the spinal axis and the sagittal sinus-arachnoid villi complex which interact with each other in the clinical patient setting. We hypothesise that changing spinal compliance by altering the flow process and CSF dynamics lead to hydrocephalus. Therefore four NPH types have been distinguished according to the alterations in spinal compliance, decrease in CSF absorption at the sagittal sinus or both occurrences. The authors consider that NPH and NPH-related diseases (NPH-RD) are initiated by the same common final pathway and demonstrate that NPH could represent an initial stage of NPH-RD. Progression of clinical signs can be explained as damage to the cerebral tissue by both intermittent increased intracranial pressure and pulse pressure waves leading to periventricular ischaemia. In addition, they believe that both volume equilibrium and spinal compliance are restored in patients who improve after CSF shunt, whereas in patients whose condition does not improve, only volume equilibrium is restored and not spinal compliance, which was the underlying cause of hydrocephalus in such cases. They therefore wonder whether cervical decompression should not be indicated in patients who show no improvement. Although attractive, this analysis warrants confirmation from clinical, radiological, and hydrodynamic studies.

Idiopathic normal pressure hydrocephalus: theoretical concept of a spinal etiology.

Normal pressure hydrocephalus (NPH) is an adult syndrome characterised by a combination of gait disturbance, varying degrees of cognitive decline, urinary incontinence, ventricular enlargement and normal mean intracranial pressure. Since this syndrome was first described, its pathophysiology has been a matter of great debate, although it is now considered that NPH could be divided into two groups: cases with unknown etiology (idiopathic normal pressure hydrocephalus, or INPH) and those which develop from several known causes (such as trauma, meningitis or subarachnoid haemorrhage). The pathophysiology of INPH is still unclear and a matter of debate. In this manuscript, the current pathophysiological conditions of INPH are analysed and the authors put forward the theory that the disease is a dynamic syndrome which occurs in patients who have suffered a significant loss of spinal compliance over time. Consequently, intracranial pressure increases more during systole in INPH patients because it cannot be compensated for by the escape of CSF into the spinal canal as effectively, due to the reduced volume or lack of distension of the spinal canal. This leads to an increase in ventricular size and causes cumulative brain damage over a long period of time and accounts for the slow, progressive nature of NPH. The loss of spinal compliance with age is fundamental to the proposed theory which provides a theoretical justification for studying the spinal canal in INPH and investigating the relationship between the progressive narrowing of the spinal canal and the compensating ability of the craniospinal system.

Pathophysiology of intracranial epidural haematoma following birth.

Epidural haematoma in newborn infants is rare, and few specific obstetrical data related to its formation are available in the literature. The aim of this study is to discuss the pathophysiology of this condition. EDH is always a post traumatic lesion and it is only possible if the insult has produced a cleavage of the dura mater from bone. Therefore, EDH results from the mechanical forces exerted on the foetal head during birth, with or with no instrumental interference. Although it is still unclear whether the injury (and dura mater cleavage) was directly caused by the forceps or had already been inflicted by natural forces, or a combination of both however, in some patients (with neither dystocia nor skull fracture), there is no basis for explaining EDH formation, apart from propulsion of the fore coming head through the birth canal. Excessive moulding, whether or not associated with iatrogenic trauma, has been incriminated in most cases of EDH. As dystocia cannot always be anticipated, EDH will remain an ever-present cause of morbidity in the neonatal population, albeit a rare occurrence.

Pathophysiology of glioma cyst formation.

Fluid filled cystic cavities are accompaniments of some cerebral gliomas. These tumoural cysts together with peritumoural vasogenic brain oedema add to the morbid effects of the gliomas in terms of mass effect and increased intracranial pressure. Although different mechanisms have been suggested as to the pathogenesis of glioma-associated cysts, it is still unclear why these cysts appear in only a limited number of cerebral gliomas while brain oedema, a probable precursor of glioma cysts, is a usual accompaniment of most gliomas. Here, the authors present a two-hit hypothesis of brain glioma cyst formation. We suggest that after the formation of vasogenic tumoural brain oedema, microvascular phenomena may lead to the formation of microcysts, which might later become confluent and grow to form macroscopic cysts. Progress in the understanding of pathogenesis of cerebral glioma cysts might set targets for treatment of brain edema and glioma cysts.

Gowers intrasyringal hemorrhage. Case report and review of the literature.

The concept of hemorrhage in a preexisting syringomyelic cavity was first described by Gowers in 1904. Since its first description only 13 cases have been reported. The aims of this report are to describe a new case, bring this entity to wider attention, and summarize the existing literature on the subject. This 36-year-old woman presented with progressive gait disturbance and unsteadiness. Physical examination revealed incomplete quadriparesis, predominantly on the left side, and hypesthesia below C-7. Magnetic resonance imaging revealed hematomyelia characterized by a heterogeneous hyperintense signal within the central cervical cord. A liquefied well-limited hematoma was evacuated. The postoperative course was uneventful; a near-complete recovery was observed at the 7-year follow-up examination. Most cases of intrasyringal hemorrhage (ISH) have occurred in syringomyelic cavities associated with scoliosis or Chiari malformation Type I. Although there is no specific clinical picture associated with this entity, it can be characterized by three neurological forms: 1) sudden onset or rapid development of signs and symptoms, 2) acute worsening of symptoms that may improve but leaving greater neurological dysfunction than before the previous episode, and 3) ISH may initiate progressive deterioration in a patient with known syringomyelia. Intrasyringal bleeding is most probably caused by a sudden dilation of the syringomyelic cavity, which may provoke rupture of the intrasyringal vessels by an acute distension of the accompanying strands. Magnetic resonance imaging is the most accurate diagnostic modality, and recognition of ISH can lead to early, safe, and efficient surgical treatment.

Pathophysiology of capillary haemangioma growth after birth.

Capillary haemangiomas (CHs) are the most common soft tissue tumours of infancy. It is generally believed that the primary defect in CHs is intrinsic to endothelial cells, but their pathogenesis is yet poorly understood. The relatively low oxygen environment, in which the human foeto-placental unit develops, during the first trimester, is necessary to induce vasculo-angiogenesis via embryonic endothelial cells proliferation, since these cells are sensitive to hypoxia and acidosis. In newborn infants with haemangioma, persistent embryonic primitive endothelial cells trapped in the intimae underneath the developing vessels, and representing "leader" endothelial cells, can stabilise the labile vascular endothelial growth factor mRNA (VEGF mRNA), produce other angiogenic factors, degrade the underlying basement membrane and invade into the stroma of the neighbouring tissue. With bearing down, the transition from intra- to extra-uterine life is accompanied by more or less pronounced hypoxia. Consequently, in babies with haemangioma, hypoxia can act as a switch to activate these "leader" endothelial cells and thereby initiate a cascade of reactions leading to CH proliferation. As they are regulated by embryonic cells, the haemangioma growth mechanisms pursue the pathway of embryonic angiogenesis and it will stop at the end of the embryonic endothelial cell cycle. Addressing this mechanism in vivo has partly been done (the angiogenic peptide bFGF varies with haemangioma growth). Thus, early treatment seems necessary in infants with haemangioma, before the endothelial cells achieve their proliferative stage. The use of an antibody to interfere with VEGF receptors provides a particular attractive strategy.

Results in the operative treatment of elderly patients with spinal meningiomas.

STUDY DESIGN: Thirty consecutive patients over 70 years of age who were operated on for spinal meningiomas are presented to assess surgical criteria and postoperative outcome. OBJECTIVES: To assess the outcome of surgically treated spinal meningiomas in patients in their eighth or ninth decade of life and to analyze the possible role of some prognostic factors. SUMMARY OF BACKGROUND DATA: The ageing of the population in the industrial nations has led to increased findings of benign spinal tumors, namely meningiomas, in the elderly. These slow-growing tumors may prevent these patients from leading an autonomous life. Little is known about the outcome of spinal meningioma surgery in patients of 70 years or older because the number of these patients, although increasing, is still small. METHODS: Thirty consecutive patients over 70 years of age (mean age, 77.1 years) were operated on for spinal meningiomas between 1986 and 2001. The preoperative neurologic status of the patients was graded with the Solero score, and the general health conditions were staged according to the American Society of Anesthesiology classification. Total tumor removal was achieved in 27 patients. The follow-up period ranged from 17 to 173 months (mean, 62.7 months). RESULTS: There was no operative mortality, and morbidity was not significant. Although not significant, neurologic outcome was better in patients with a low preoperative Solero score than those with a high one (P = 0.06). Clinical outcome was not influenced by the duration of symptoms before surgery or preoperative American Society of Anesthesiology classification. No recurrence was observed during the follow-up period. CONCLUSIONS: Neurologic outcome following surgery was favorable in the vast majority of patients, with no mortality or significant morbidity. Surgery is the only treatment in elderly patients with symptomatic spinal meningiomas, even those with a poor preoperative neurologic condition, whenever there is an acceptable risk from an anesthesiological point of view.

Cerebellar malignant fibrous histiocytoma: case report and literature review.

OBJECTIVE AND IMPORTANCE: Malignant fibrous histiocytoma in the central nervous system is uncommon. Fewer than 70 cases have been documented and, to the best of our knowledge, this is the first case arising from the cerebellum. CLINICAL PRESENTATION: A 44-year-old woman presented with headaches, vomiting, and dizziness. A neurological examination revealed right cerebellar syndrome. Brain computed tomographic scans revealed an isodense tumor in the right cerebellar hemisphere. The breast ultrasonographic, bone scintigraphic, and thoracoabdominal computed tomographic findings were normal. INTERVENTION: The patient was surgically treated. The tumor recurred 1.5 months later, demonstrating hemorrhagic characteristics on brain computed tomographic scans. The patient underwent a second operation, followed by radiotherapy. CONCLUSION: Malignant fibrous histiocytoma is still a controversial entity, and the lack of specific criteria means that it must be diagnosed via the process of elimination. With currently available therapy, our review can provide only a very poor prognosis. The median survival time was 27 months. In attempts to develop better therapeutic strategies, total excision and radiotherapy seem to represent the best treatment approach.

Acute cauda equina compression revealing Hodgkin's disease: a case report.

STUDY DESIGN: This is a case report of a young patient who experienced an acute epidural compression of cauda equina revealing Stage IV Hodgkin's disease. OBJECTIVES: To draw attention to this rare presentation of Hodgkin's disease, and to assess the role of surgery in acute cauda equina compression in a context of a chemosensitive disease. SUMMARY OF BACKGROUND DATA: Lymphomatous tissue in Hodgkin's disease may involve the spine usually in the setting of advanced disease. Initial manifestation of Hodgkin's disease in the spine is rare. The management of this rare presentation may be conservative, but surgery provides the most rapid way of neurologic tissue decompression. METHODS: The case of a 14-year-old patient who experienced an acute epidural compression of cauda equina revealing Stage IV Hodgkin's disease is presented. RESULTS: The patient complained of an increased lower back pain of 1-month duration before he developed lower limbs numbness, loss of perineal sensation, and urinary retention. Sagittal and axial T2-weighted magnetic resonance images of the lumbar spine revealed tumoral invasion of the epidural space compressing the cauda equina. Emergency surgical decompression was performed. In fine, Stage IV Hodgkin's disease revealed by acute epidural cauda equina compression was diagnosed. The patient recovered normal neurologic functions in a few days and then underwent chemotherapy and radiotherapy. CONCLUSION: Although a rare situation, Hodgkin's disease may involve the spinal epidural space at presentation. The management is complex, but surgery provides the most rapid means of diagnosis and neurologic tissue decompression in severely affected patients.