The microvascular network of the pituitary gland: a model for the application of fractal geometry to the analysis of angioarchitecture and angiogenesis of brain tumors.

In geometrical terms, tumor vascularity is an exemplary anatomical system that irregularly fills a three-dimensional Euclidean space. This physical characteristic, together with the highly variable vessel shapes and surfaces, leads to considerable spatial and temporal heterogeneity in the delivery of oxygen, nutrients and drugs, and the removal of metabolites. Although these biological features have now been well established, quantitative analyses of neovascularity in two-dimensional histological sections still fail to view tumor architecture in non-Euclidean terms, and this leads to errors in visually interpreting the same tumor, and discordant results from different laboratories. A review of the literature concerning the application of microvessel density (MVD) estimates, an Euclidean-based approach used to quantify vascularity in normal and neoplastic pituitary tissues, revealed some disagreements in the results and led us to discuss the limitations of the Euclidean quantification of vascularity. Consequently, we introduced fractal geometry as a better means of quantifying the microvasculature of normal pituitary glands and pituitary adenomas, and found that the use of the surface fractal dimension is more appropriate than MVD for analysing the vascular network of both. We propose extending the application of this model to the analysis of the angiogenesis and angioarchitecture of brain tumors.

Lumbar arachnoiditis and thecaloscopy: brief review and proposed treatment algorithm.

The term arachnoiditis describes the inflammation of the meninges and subarachnoid spaces. Lumbar arachnoiditis is characterized by obliterated nerve root sleeves and the adherence of nerve roots to each other in the proximity of the cauda equina, and may be secondary to infectious diseases or tumors, iatrogenic (subsequent to spinal surgery) or idiopathic. It is not very clearly defined epidemiologically or clinically, and various theories regarding its pathophysiology have been proposed; furthermore, its treatment is difficult because there is a lack of evidence-based diagnostic and therapeutic gold standards. Thecaloscopy has been recently described as a novel technique for retrograde transcutaneous neuroendoscopic inspection of the subarachnoid structures of the lumbar thecal sac; it has also been suggested for the treatment of lumbar arachnoiditis. We here review the most modern techniques for the treatment of this disease such as thecaloscopy and neurostimulation.

TOS pathophysiology and clinical features.

The authors present 280 patients operated on for thoracic outlet syndrome (TOS). In a first group of patients anatomical variants were the striking findings. The underlying factor for TOS development is therefore a well defined structural condition and its pathogenetic mechanism is known to be a nerve fibre compression. In a second group there was no specific salient finding but a postural deviation. The unique pathological features were adhesions of the brachial plexus to the scalenus muscle. Consequently its pathogenetic mechanism is generally recognized as nerve fibre distraction. In all patients neurological, vascular and myofascial pain symptoms were observed before the operation. Neurological and vascular pain disappeared after surgery, while the myofascial pain remained. The authors believe that especially in the second, larger group of patients enhancement of the pain-immobility-fibrosis loop is the central pathogenetic factor on which surgical therapy is successful, and that myofascial hemisyndrome--probably arising from a long-standing postural deviation--is not a TOS dependent symptom. In TOS, therefore, there is a pain loop that cannot be resolved by surgical therapy alone. The connection between myofascial pain syndrome and TOS might explain the many controversial opinions regarding frequency, results and surgical possibilities of this lesion.

Post-traumatic thoracic outlet syndrome (TOS).

TOS is a compressive non-tumorous syndrome of the brachial plexus. It is possible, however, to consider as TOS the irritative and lesional plexus syndrome following trauma as long as compression (or traction) on the nerves is triggered by long-lasting pathological changes of the area after trauma. Overload work of judges and lawyers after traffic accidents does not help to remind the real victim's problem, that is stretching of the neck soft tissues during head acceleration-extension. This movement is due to a forward acceleration. Both the car and the victim's trunk are violently pushed forward while the head does not move fast enough so that it is actually pushed backwards. The mandibula is even slower than the head and this leads to an opening of the mouth with possible temporomandibular joint (TMJ) dislocation. If there is nothing stopping the neck extension, like an appropriate headrest, the momentum is only resisted by cervical soft tissue stretching. Prolonged antalgic contracture and motor neglect may contribute to connective tissue changes and development of microadherences. Final result is fibrosis of paraneurium. The pain-immobility-fibrosis loop is of basic importance in the development of this syndrome.

Entrapment of crural branches of the common peroneal nerve.

Failed back surgery syndrome (FBSS) occurs in 30% of operated patients and represents a heavy problem both regarding disability and costs in first world countries. Among FBSS we found the possibility of a double crush syndrome: a disco-radicular conflict and a peripheral nerve entrapment. The latter, disguised by root compression symptoms, becomes evident only after spinal surgery. Clinical features are the same as for the restless leg syndrome. We found peroneal nerve crural branches entrapped where they crossed the fascia to reach the subcutaneous layer. Venous stasis during immobility caused presentation of symptoms. Neurolysis was performed, all cases were successful. Most of the patients were found to have myofascial pain syndrome (MPS). MPS patients "feel" entrapments more frequently than others not because of their specific pain tolerance but because they are more prone to develop them.

Neuroendoscopy: one year of experience--personal results, observations and limits.

After reading reports of successful neuroendoscopic treatment of hydrocephalus, colloid cysts and arachnoid cysts as well as tumor biopsy, we started using endoscopic procedures in our Department, one year ago. One surgeon (E.S.) skilled in the Decq Endoscope, performed a series of sixteen procedures, from January 2001 to March 2002 (in patients aged 28 to 69 years). The most common pathology was obstructive hydrocephalus (14 cases), one was colloid cyst, and the last case was tumor biopsy. The surgical treatment consisted of third ventriculostomy, cyst opening and shrinking and tumor biopsy. In fourteen patients treated for hydrocephalus with third ventriculostomy (ETV), one required a definitive shunt. Complication occurred in one case with chronic subdural collection. We further report one case of aqueductal restoration after third ventriculostomy. Our results, with no neurological deficits or deaths, confirmed our opinion that neuroendoscopy is a safe surgical technique in well-selected patients and we believe it is the ideal treatment in obstructive hydrocephalus.

Overdrainage after endoscopic third ventriculostomy: an unusual case of chronic subdural hematoma--case report and review of the literature.

Endoscopic third ventriculostomy is considered a safe technique for the treatment of obstructive hydrocephalus. However, the literature contains several reports of complications related to this procedure. We describe a case of chronic subdural hematoma (CSDH) after ETV, which required surgical evacuation, in a 69-year-old male patient completely asymptomatic up to the control MRI four weeks after the operation. We believe this unusual complication could result from the ICP changes caused by ETV. In our opinion, successful ETV gives a boost to CSF absorption, and overdrainage may evolve also in endoscopic treatment of obstructive hydrocephalus. This situation could be the starting point of the subdural collection. We review the literature and discuss the causes that may lead to CSDH after ETV procedure.

"Matrioska head". Case report of calcified chronic subdural hematoma.

We report an asymptomatic case of a large calcified chronic subdural hematoma (CCSH). Skull X-ray examination, computer tomography (CT) and magnetic resonance imaging (MRI), showed an adhering calcification extending to the whole cerebral cortex, as if the skull had another concentric skull inside it. These radiological findings recall the famous Russian doll named "Matrioska"; for this reason we defined this case "Matrioska head". The patient was absolutely asymptomatic and we discuss the causes that may give the calcification of chronic subdural hematoma (CSH).

A cervico-dorsal intramedullary epidermoid cyst. Case report and review of the literature.

Intramedullary epidermoid cysts are rarely observed. Only a little more than 30 cases have been reported in the literature. The authors have treated a 51 year-old woman with a cervico-dorsal intramedullary epidermoid tumor associated with a syringomyelia. The frequency of this lesion, its CT and MRI appearance and the possibility of a preoperative diagnosis are discussed.

Traumatic fractures of the craniovertebral junction. Management of 23 cases.

Twenty-three consecutive cases of traumatic C1-C2 fractures treated at the Department of Neurosurgery, University of Milano, are reported. Of these there were 13 cases of odontoid fractures, 6 hangman fractures, 2 anterior inferior corner fractures, 2 atlas-axis combination fractures and 2 Jefferson fractures. Almost all the patients were young people involved in motor vehicle accidents. Nineteen patients were treated with external immobilization (halo vest, Minerva) for 3-6 months while 4 odontoid fractures underwent early surgical posterior stabilization. At follow-up, 20 patients had a good fusion while 3, aged over 75 years, died due to cardiopulmonary or septic complications. The appropriate management of this type of lesion is still a matter of discussion. In our opinion the Halo device allows good stabilization after correct fracture reduction.

Treatment of intracranial meningiomas in patients over 70 years old.

The neurosurgeon often finds himself in the position to having to decide whether or not to operate on an elderly patient suffering from intracranial meningioma. The decision is rarely easy and the results often disappointing. We studied 46 cases of intracranial meningioma in patients over 70 years of age, 34 patients were operated on while 12 patients were not, although both groups were subjected to long term follow-up. The operative mortality rate was 12%, a rate which increased to 20% at 3 months follow-up. Various unfavourable prognostic factors were taken into consideration, the most significant of which were: poor overall clinical condition, peritumoral oedema, the presence of diabetes mellitus and the duration of surgery. A scored grading system was created to standardize surgical indications in elderly patients with cerebral meningioma. An analysis of the grading system, when applied to patients submitted to surgery, showed that the decreased patients within 3 months of surgery had a score which varied from 7 to 12, with a mean score of 10. The surviving patients had a score averaging from 10 to 16 with a mean of 13. The patients with the lowest scores (7-9) had a 100% mortality rate while those in the upper ranges (13-16) demonstrated a mortality rate of 0%. Among the conservatively treated patients the worst outcome was seen in patients with a grading equal to or less than 12.

[Cervical vertebral and spinal cord injury in intensive therapy]. / Il trauma vertebro-midollare cervicale in terapia intensiva.

24 of 184 patients with vertebro-medullary trauma admitted to the Neurosurgery Clinic of Milan University in the years 1976-1988 have been examined. A common feature of these was a myelic lesion (transverse, complete or incomplete) at cervical level in which respiratory problems had made a period of intensive care indispensable. The purpose of the research was to assess the reliability of certain parameters in establishing patient prognosis. The following parameters were compared: clinical, objective and instrumental examination for a strictly neurological evaluation and for an evaluation of general condition, quantification of the same clinical examination through two scales, the Sunnybrook Cord Injury Scale (SCIS) for the neurological factor and the APACHE II for general condition, the type of treatment, with the same basic medical-resuscitation treatment. The result of the surgery or non-surgery was considered a posteriori. It is concluded that, in the case of the patients considered (high myelic lesion) the prognosis must be split into two different moments that the patient goes through in succession: the acute phase and the stabilisation phase. In the first phase, in which the vital functions are involved, the SCIS and APACHE II scales (with their sum) have great prognostic value; in the second phase, certain values, already considered on the APACHE II scale, are comparable in all patients and the prognostic problem is based on the other scale (SCIS) and on the adjuvant neurophysiological techniques. The very distinction between the two different phases that the patient traverses appears important also for the purposes of surgical indication.2

Subarachnoid haemorrhage due to acoustic neurinoma. Case report and review of the literature.

One case of spontaneous subarachnoid haemorrhage due to acoustic neurinoma is presented. The literature regarding this subject is reviewed and the pathogenesis of haemorrhage from neurinoma is discussed.

Supracondyloid process and anomalous insertion of pronator teres as sources of median nerve neuralgia.

A case of median nerve entrapment at the elbow between the supracondyloid process and the anomalous origin of the pronator teres on it is presented. The anatomical variant and the histological background of this syndrome are outlined. The pathophysiology of the neuralgia is discussed. A relatively simple surgical procedure afforded complete relief of symptoms.

Cranial defects repair by replacing bone flaps.

The Authors, after few historical remarks, discuss the indications and the contra-indications for cranioplasty. Although, in the last 30 years, various materials and techniques have been investigated and proposed, the Authors suggest, as method of choice, the reimplantation to each patient of his own volet, when possible, to repair skulls defects. This technique in fact permits to restore an almost normal physiological condition of the cranial vault functions. In the light of the recent researches on the "bone induction principle" and on the possibility of storing at a temperature of -30 degrees C in a freezer the bone flap in ideal condition before the reimplantation, this method is proposed again. The Authors report their experience on 15 patients, 13 of whom have been successful; a perfect aseptic storage, a rational choice of the patients who should be treated and a correct surgical approach are underlined as mandatory for the successful use of the technique. The mean follow up for the 13 successful patients is 15 months. In the paper the 2 unfavourable cases are discussed too: the hypothetical causes which lead to reject of the reimplants are suggested and debated.

Severe traumatic coma in infancy and childhood: results after surgery and resuscitation.

This study deals with 390 cases of severe traumatic coma in infancy, childhood and youth, aged between 4 months and 19 years. Cases in which unconsciousness lasted less than 24-48 hours have not been considered here. 161 patients were operated upon for intracranial space-occupying lesions or for open head injury: extradural haematomas 60; extradural haematomas + brain lacerations and/or subdural haematomas 16; acute subdural haematomas 18; brain laceration 36; open head injuries 17; decompressive operations, hydromas and contusions 14. 102 patients recovered and 59 died. 229 subjects were given only to resuscitation treatment. 164 recovered and 65 died. Recovery and mortality rate are discussed in relation to the pathologicial lesions and to the clinical picture (severity, evolution and duration of coma). Overall mortality rate was 31%. Mortality was higher in operated patients (36.6%) and lower in patients in whom space-occupying lesions were not demonstrated by angiography and who underwent only resuscitation treatment (28%). The lowest rate was observed in cases of extradural haematoma (25.4%) and open head injury (23%). Highest mortality rate have been observed in cases of decerebrated coma (with or without signs of low brain stem impairment). Complete recovery can be achieved even after prolonged decerebration. 31 patients showed the typical picture of the "apallic syndrome": in 28 cases after prolonged decerebrated coma, in 3 cases after coma without decerebration. Of our 31 cases, 4 died, 4 are still in a chronic apallic state and 23 recovered. Of these, 10 patients had a remarkable recovery and 13 remained severely disabled.