Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

Cerebellar Mutism after Medulloblastoma Resection: Importance of MR Features

We describe the MR features which appeared after resection of a medulloblastoma in the posterior fossa in a boy who developed postoperative cerebellar mutism. The anatomical and physiopathological factors responsible for this disorder are discussed.

Pattern of care and effectiveness of treatment for glioblastoma patients in the real world: Results from a prospective population-based registry. Could survival differ in a high-volume center?

BACKGROUND

As yet, no population-based prospective studies have been conducted to investigate the incidence and clinical outcome of glioblastoma (GBM) or the diffusion and impact of the current standard therapeutic approach in newly diagnosed patients younger than aged 70 years.

METHODS

Data on all new cases of primary brain tumors observed from January 1, 2009, to December 31, 2010, in adults residing within the Emilia-Romagna region were recorded in a prospective registry in the Project of Emilia Romagna on Neuro-Oncology (PERNO). Based on the data from this registry, a prospective evaluation was made of the treatment efficacy and outcome in GBM patients.

RESULTS

Two hundred sixty-seven GBM patients (median age, 64 y; range, 29-84 y) were enrolled. The median overall survival (OS) was 10.7 months (95% CI, 9.2-12.4). The 139 patients ≤aged 70 years who were given standard temozolomide treatment concomitant with and adjuvant to radiotherapy had a median OS of 16.4 months (95% CI, 14.0-18.5). With multivariate analysis, OS correlated significantly with KPS (HR = 0.458; 95% CI, 0.248-0.847; P = .0127), MGMT methylation status (HR = 0.612; 95% CI, 0.388-0.966; P = .0350), and treatment received in a high versus low-volume center (HR = 0.56; 95% CI, 0.328-0.986; P = .0446).

CONCLUSIONS

The median OS following standard temozolomide treatment concurrent with and adjuvant to radiotherapy given to (72.8% of) patients aged ≤70 years is consistent with findings reported from randomized phase III trials. The volume and expertise of the treatment center should be further investigated as a prognostic factor.

Revascularized giant aneurysm of the anterior communicating artery after surgery and embolization, occluded by placement of a Leo+Baby intracranial stent. A case report

Balt (Montmorency, France) recently manufactured the Leo+Baby dedicated intracranial stent for arteries with a calibre between 1.5 and 3.10 mm. We describe a patient with a partially thrombosed giant sacciform aneurysm of the anterior communicating artery treated without success by surgery and coil embolization subsequently occluded by placement of a Leo+Baby stent (Balt, Montmorency, France). A 56-year-old man presented with a giant aneurysm in the anterior communicating artery region. Following successive surgical intervention and embolization procedures the patient was referred to us with a revascularized aneurysm measuring 15×9×8 cm. To stabilize the endovascular occlusion a combined treatment was scheduled with coil embolization and stent deployment after dual antiplatelet therapy started five days before the interventional procedure. Treatment was undertaken two weeks later under general anaesthesia and total heparinization. A microcatheter was inserted into the aneurysmal sac and four metal coils were released for a total of 61cm obtaining almost complete occlusion of the aneurysm from the circulation. A Leo+Baby stent (2.5×18 mm) was subsequently deployed across the aneurysm neck. At follow-up angiography two months later the aneurysm appeared substantially excluded from the arterial circulation except for a small portion in the neck. Six months later, four months after suspending antiplatelet therapy, follow-up angiography disclosed the complete exclusion of the aneurysm from the circulation. Deployment of the new ministent through the same microcatheter used to release the coils made the interventional procedure simpler and faster.

Focal epilepsies associated with glioneuronal tumors: review article

Glioneuronal tumors (GNTs) are an increasingly recognized cause of focal epilepsies, particularly in children and young adults. GNTs consist of a mixture of glial and neuronal elements and most commonly arise in the temporal lobe, particularly in the temporo-anterior-basal mesial site. They are often associated with cortical dysplasia or other neuronal migration abnormalities. Epilepsy associated with GNT is poorly controlled by antiepileptic drugs in many cases; but, it is extremely responsive to surgical treatment. However, the best management strategy of tumor-related focal epilepsies remains controversial and still remain one of the contemporary issues in epilepsy surgery. Temporo-mesial GNT are associated with a widespread epileptic network, defining, therefore, a distinct anatomo-clinico-pathological group with complex epileptogenic mechanisms. By using an epilepsy surgery oriented strategy GNT associated with focal epilepsies may have an excellent seizure outcome and, therefore, surgical treatment can be offered early to avoid both the consequences of uncontrolled seizures as well as the side effects of prolonged pharmacological therapy and the rare risk of tumor growth or malignant transformation.

Endoscope-controlled microneurosurgery for the treatment of intracranial fluid cysts

OBJECTIVE

This study assessed the role of endoscope-controlled microneurosurgery (ECM) in the treatment of intracranial cerebrospinal fluid (CSF) cysts.

METHODS

Twelve patients affected by symptomatic arachnoid cysts (11 in the sylvian fissure and 1 in the cerebellopontine angle) underwent ECM, in which the endoscope is used to view the operating field while microsurgical instruments can be passed alongside the endoscope for surgical maneuvers. All the cysts were superficially located and could be reached directly through a burr hole on their surface, so that the endoscope was inserted into the cyst without passing through the brain parenchyma. We used a rigid endoscope, performing a wide fenestration of the cyst in the basal cisterns (cystocisternostomy). The excellent endoscopic vision facilitated the surgical procedure with safe maneuvers through a minimally invasive approach. In 11 patients, we observed the resolution of symptoms. A radiological reduction in the cyst was observed in 7 cases. No mortality or major complications were observed.

CONCLUSIONS

Endoscope-controlled microsurgery is a valid minimally invasive procedure for treating superficially located intracranial arachnoid cysts.

Bobble-head doll syndrome due to a suprasellar arachnoid cyst: endoscopic treatment in two cases

OBJECT

We report two cases of bobble-head doll syndrome associated with a large suprasellar arachnoid cyst successfully treated with a minimally invasive endoscopic approach.

METHODS

The clinical history, surgical treatment and results of two children, a 9-year-old boy and a 1-year-old girl, both presenting the clinical features of the bobble-head doll syndrome, are described. As a first procedure, a ventriculo-cystostomy was endoscopically performed in both patients, obtaining either resolution of the symptoms or notable cyst reduction. In the girl, a re-closure of the stoma, with cyst re-expansion, was observed after 18 months. She then underwent a second procedure, a ventriculo-cysto-cisternostomy, with a good result. After 3 years' follow-up, the neurological condition of both patients remains good with complete resolution of abnormal head movement.

CONCLUSION

In our opinion, endoscopic treatment is the procedure of choice for this condition, as it involves few complications and gives good results.

[A case of cerebral coenurosis]

In this article the authors describe a case of cerebral coenurosis, a rare infection caused by the larval stage of the tapeworm Taenia multiceps, encountered during their professional practice. The specific epidemiological elements, linked to the parasitic lifecycle in dogs, will also be covered. The authors consider the diagnostic, pathologic and clinical elements that allow differential diagnosis with respect to neurocysticercosis, a parasitic infection caused by the larval form of other Cestoda, discussing possible medical therapeutic approaches (albendazole or praziquantel) and neurosurgical intervention. They emphasize the need to obtain a correct hystopathological diagnosis in order to achieve a differential diagnosis versus the other larval parasitosis. According to current public health regulations this diagnosis must be reported to the Health Official to allow the necessary epidemiological interventions to be planned.

Early ictal speech and motor inhibition in fronto-mesial epileptic seizures: a polygraphic study in one patient

OBJECTIVE

To investigate ictal motor inhibition occurring during seizures in a patient with a tumor located in the left fronto-mesial pre-central cortex.

METHODS

Awake and sleep video-polygraphic monitoring, recording scalp EEG and EMG activities from several cranial, trunk and limbs muscles, was performed in a patient with drug-resistant recurrent focal motor seizures before surgical treatment. Speech/motor tasks were repeatedly administered to the patient during the recording sessions in order to evaluate the occurrence of early ictal motor inhibition.

RESULTS

Thirty-four seizures were recorded during wakefulness showing a stereotyped pattern of inhibition of speech and voluntary movements followed by sequential activation of upper limb-trunk-lower limb muscles contralateral to the tumor. Polygraphic recordings showed that: (1) initial speech and motor arrest were associated with the EMG evidence of progressive muscle tone suppression in cranial and right distal upper limb muscles; (2) tonic contraction of right deltoid, biceps brachii, intercostalis and paraspinalis muscles appeared after motor inhibition; (3) tonic-clonic activity in the right tibialis anterior muscle occurred at the end of seizures. Eleven subclinical seizures were recorded during sleep showing mild focal tonic EMG activity in right side trunk muscles.

CONCLUSIONS

Our findings evidenced early and somatotopically organized inhibition of voluntary movement at the beginning of epileptic seizures with fronto-mesial onset. The demonstration that speech and motor arrest were associated with progressive EMG suppression in cranial and limb muscles supports the hypothesis of motor inhibitory seizures originating in the mesial aspect of pre-motor frontal cortex.

Hypertension, hyperekplexia, and pyramidal paresis due to vascular compression of the medulla

MRI showed impingement of the vertebral artery on the left lateral medulla in two patients with arterial hypertension, exaggerated startle reflexes (hyperekplexia), and progressive spastic paresis. One patient underwent microvascular decompression with normalization of arterial hypertension, disappearance of hyperekplexia, and improvement of spastic paresis. The combination of arterial hypertension, hyperekplexia, and progressive spastic paresis should arouse suspicion of neurovascular compression of the lateral medulla.

Therapeutic considerations in cerebellopontine angle lipomas inducing hemifacial spasm

Lipoma is a very rare tumour at the cerebellopontine angle. We report a case of incomplete hemifacial spasm, associated with a lipoma involving and compressing both facial and acoustic nerves at their origin in the brainstem. The patient was treated with medical therapy (botulinum toxin A) and surgery. We present a review of the last ten years of the literature, with particular regard to management.

[Metastasis of pleural malignant mesothelioma to the brain and upper maxilla: description of 2 cases]

Two cases of malignant mesothelioma metastatic to the brain and maxillary bone respectively are reported. This latter localization has never been described in literature. The diagnosis resided primarily on immunohistochemistry.

Small acoustic neuromas: monitoring the growth rate by MRI

In a proportion of small acoustic neuroma patients, monitoring with magnetic resonance imaging shows no volumetric increase of tumour size over the years. The object of the study was to identify some indications for the clinical choice between immediate surgery (with the related risks) and watchful waiting. We performed a retrospective study of 47 non-surgically-treated patients affected by acoustic neuroma and monitored by gadolinium-enhanced MRI between January 1990 and February 1999. Six clinical variables (tumour size, sex, age, initial symptoms, ABR pattern and duration of the symptoms) were examined by univariate analysis. Chi-square test and variance analysis were performed to evaluate the statistical significance. In 30/47 (63.8%) cases, no growth was observed during the entire period of follow-up. In the remaining 17/47 (36.2%) patients, a volumetric increase was detected, most often within the first year of observation. The clinical factors examined did not significantly correlate with growth. Despite the relatively short period of observation, we believe that immediate surgery does not need to be considered mandatory for small acoustic neuromas, even in young patients. However the irregular behaviour of the tumour underlines the importance of monitoring with MRI at least once a year.

Expanding lacunae causing triventricular hydrocephalus. Report of two cases

Two patients are reported in whom the presence of triventricular hydrocephalus and aqueductal obstruction or stenosis due to multiple expanding lacunae in the mesencephalothalamic region possibly corresponds to abnormally dilated perivascular spaces. Placement of a ventriculoperitoneal cerebrospinal fluid (CSF) shunt in one patient and the performance of a third ventricle cisternotomy in the other reversed the hydrocephalic syndrome, but did not modify the complex neuroophthalmological disturbance and rubral tremor presumably related to the compressive effects of the lacunae on adjacent parenchyma. In one patient the number and size of the lacunae were increased 4 years after CSF shunt placement. A review of the literature revealed two cases in which magnetic resonance imaging demonstrated a similar, poorly understood pathological condition.

[Cytogenetics of tumors of the central nervous system: a case study and review of the literature]

The introduction of cytogenetic techniques, especially chromosome banding techniques, has facilitated a more detailed study of the chromosomal basis of hematological malignancies and solid tumours. With the advent of molecular cell biology many new insights have been gained into the pathogenetic mechanisms of cancer. With G banding technique we have studied chromosomal aberrations of 174 tumours of the Central Nervous System in adults and the results obtained have been compared with the literature data.

Osseous metaplasia in a growth hormone-secreting pituitary adenoma

A case of growth hormone-secreting adenoma of the pituitary gland showing osseous metaplasia is described in a 56-year-old acromegalic female. The tumor was composed of nests of densely granulated cells separated by and intermixed with calcifications, trabeculae of mature bone and fat. Calcifications are seldom found in pituitary adenomas. In rare instances, calcium deposits can be prominent enough to lead to the formation of pituitary stones and bone which replace the entire tumor mass. Analogously with metaplastic meningiomas, we propose using the term metaplastic adenoma to define cases with osseous metaplasia in order to distinguish between lesions containing bone from the more frequently seen calcified adenomas.

Cytogenetic investigation of chordomas of the skull

We report the first cytogenetic investigation of cranial chordoma. Three cranial chordomas were examined, two of which could be further histopathologically classified as chondroid chordomas. In addition, we have included a case of chordoma of a cervical vertebra to compare the cytogenetic abnormalities. Diagnosis was made at histological and immunohistochemical levels. The three cases of cranial chordoma showed a normal karyotype, while one vertebra showed 46,XY,t(6;11)(q12;q23). Chordomas, particularly those containing cartilage, have to be distinguished from chondrosarcomas of the skull base. Such a distinction is normally based on expression of epithelial markers which usually are lacking in chondrosarcoma. Cytogenetic investigation may eventually prove to be useful in the distinction of the two lesions, if chromosome anomalies are consistently absent in chordoma, although some chondrosarcomas may also present a normal karyotype. Such a distinction has clinical implications because chondroid chordomas show better survival, whereas chondrosarcomas show a propensity to infiltrate the surrounding tissues.

High-performance liquid chromatographic analysis of physiological amino acids in human brain tumors by pre-column derivatization with phenylisothiocyanate

A reversed-phase high-performance liquid chromatographic technique for the determination of free amino acids in five biopsies of human brain tumors (two meningiomas, one glioblastoma and two oligodendrogliomas) is described. The frozen tissues were homogenized, deproteinized with perchloric acid and neutralized with potassium hydroxide. Aliquots of the supernatant containing the physiological amino acids are used for pre-column derivatization with phenylisothiocyanate. The derivatized PTC-amino acids (phenylthiocarbamyl derivatives) are stable for a five day period if stored as a powder at -20 degrees C in an inert atmosphere and they can be analyzed on a reversed-phase column (PicoTag) using a gradient of two eluents with absorption detection at a wavelength of 254 nm. Good resolution of several amino acids (>30) is achieved within ca. 60 min. For most amino acids this method is suitable for an accurate measurement over a wide range of physiological concentrations (50-400 pmol) starting from a very small amount of sample.

Magnetic resonance spectroscopy study of low grade extra and intracerebral human neoplasms

In this study we report an in vitro 1H magnetic resonance spectroscopy (MRS) characterization of water soluble metabolites obtained from 17 low grade extra and intracerebral human tumors (8 meningiomas, 5 oligodendrogliomas, 2 subependimomas and 2 ependimomas). In addition, the in vivo localized 1H MRS results for 4 of the meningiomas are reported. The main metabolic features characterizing low grade tumors were investigated. Meningiomas are characterized by high Cho/Cr and Ala/Cr ratios; in many cases both in the in vitro and the in vivo spectra these ratios cannot be evaluated, due to the absence of the Cr metabolite. Low grade oligodendrogliomas are characterized by low Cho/Cr ratios. High amounts of myo-inositol are found in the spectra of ependimomas and subependimomas which are distinguished by different Cho/Cr ratio values and by a different Ala content.

[Metastasis in the inner auditory canal]

Metastasis in the inner auditory canal (IAC), or more precisely in the pontocerebellar angle (PCA) is extremely rare. Indeed acoustic neurinoma (AN), meningioma and other types of benign neoformations, in decreasing order, account for nearly all expansive pathologies in this anatomical region. The present paper reports a clinical case of a patient with the sudden onset of an hearing loss in the right ear. This hearing loss was promptly followed by paralysis of the homolateral facial nerve. The function of both cranial nerves worsened progressively and rapidly. Cerebral radiology, performed with MRI and the administration of gadolinium, showed a AN-compatible neoformation fundamentally affecting the IAC. However, histological tests performed after surgery indicated an adenocarcinoma. Post-operative instrumental tests identified the primary neoplasm in the lower lobe of the right lung. The purpose of this work was to highlight, in view of the literature on the topic, the main clinical aspects to consider when a malignant expansion is suspected in the PCA. Naturally there is greater basis for such suspicion when a primary malignant neoplasm has previously been diagnosed. Generally AN progresses quite gradually, in line with an extremely slow growth rate. Therefore it is normally seen in a progressive worsening of hearing, tinnitus and equilibrium disorders. Appearance of a facial nerve palsy is strictly limited to relatively large neoplasms and is encountered at a later stage. This is why a rapid progression of hearing damage accompanied, or promptly followed, by complete facial nerve paralysis must alert one to the possibility of a PCA malignancy. Imaging does not permit easy pre-operative diagnosis since the radiological signs and morphologies are often quite similar to those produced by AN. Therefore, post-operative histological examination can hold some surprises.

[Intracranial location of a case of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) mimicking meningioma]

Sinus histiocytosis with massive lymphadenopathy was first described in 1969 in lymphnodes by Rosai and Dorfman ad subsequently in other organs including skin, bone ad soft tissue. Extranodal involvement has also been recognised, but central nervous system manifestations are extremely rare and clinical and radiological findings are suggestive of meningioma. We report a meningeal nodule in a young woman, clinically diagnosed as possible meningioma. A review of literature of previously reported intracranial lesions is presented.

Granulomatous hypophysitis caused by a ruptured intrasellar Rathke's cleft cyst: report of a case and review of the literature

OBJECTIVE AND IMPORTANCE

Ruptured Rathke's cleft cyst is a rare cause of giant cell granulomatous hypophysitis. Chronic inflammatory reaction is caused by extravased cyst content into the adjacent gland. We provide a demonstration that mucins produced by cells lining the cyst wall caused the granulomatous giant cell reaction.

CLINICAL PRESENTATION

A 37-year-old nonpregnant woman presented with a 3-year-history of headache and amenorrhea. She had experienced normal sexual maturation, and her medical history was unremarkable. Radiologically, the lesion appeared as an intrasellar mass with a cystic component indistinguishable from a pituitary adenoma with cystic degeneration.

TECHNIQUE

The patient underwent a transsphenoidal approach. Because no demarcation between normal and affected tissue was evident at surgery, the lesion and residual pituitary were radically removed. Tissue was studied using routine hematoxylin and eosin and histochemical stainings for mucins and immunocytochemical techniques.

CONCLUSION

This study demonstrates that mucins that had spilled out from the cyst caused the granulomatous reaction. Using computed tomography, magnetic resonance imaging, and gross inspection, distinction between granulomatous hypophysitis and pituitary adenoma was virtually impossible. Nevertheless, a granulomatous reaction of the pituitary gland should be suspected in a case of a sellar mass having a cystic area. In such cases, intraoperatory diagnosis on frozen sections is mandatory because adoption of a conservative treatment allows preservation of the gland.

[Cytogenetic analysis of hypophyseal adenoma. Study of 9 cases and review of the literature]

INTRODUCTION

To the best of our knowledge, no specific chromosomal abnormalities have been found in the literature in pituitary adenomas. In the present study, we investigated 9 cases of pituitary adenoma and reviewed the current literature.

MATERIALS AND METHODS

Nine cases of pituitary adenoma have been studied with immunohistochemistry and cytogenetic using short-term cultures.

RESULTS

All tumors had a normal karyotype. Three cases were clinically non-secreting adenomas, three cases produced prolactin, two showed growth hormone production and one thyroid-stimulating hormone. One of the cases showed dural invasion.

CONCLUSIONS

We compared our results with those published in the current literature. It appears that pituitary adenomas do not have specific numerical and structural abnormalities and mostly show a normal karyotype.

In vivo single voxel 1H MRS of glial brain tumors: correlation with tissue histology and in vitro MRS

Eighteen patients affected by glial brain tumors were examined by localized single voxel magnetic resonance spectroscopy (1H MRS). For all patients histological diagnosis was obtained after stereotactic biopsy or surgical removal of the tumor. Histological nuclear atypia, tumor cellularity, necrosis, vascular proliferation and percentage of Ki-67 positive cells in the total cell populations were evaluated. It was found that some of the in vivo 1H MRS parameters were related to the histological features of the tumor. In particular, the Choi/Cri metabolite ratio obtained from the neoplastic tissues paralleled the Ki-67 cell proliferation index. For some of the patients 1H and 13C in vitro high resolution magnetic spectroscopy of surgical specimens was also carried out. 1H MRS of aqueous extracts from different biopsy specimens of the same tumor furnished fine biochemical information on intratumor heterogeneity. The degree of histological vascular proliferation of the tumor was correlated to the presence of cholesteryl esters in the 13C spectrum of the lipid fraction of surgical specimens.

Oncocytic meningioma

Six cases of meningioma showing oncocytic changes are described. The lesions were composed mostly of sheets, nests, and cords of large polygonal cells with finely granular eosinophilic cytoplasm rich in mitochondria. Neoplastic cells showed nuclear pleomorphism with prominent nucleoli. Necrosis and high mitotic rate were present in the majority of cases. Oncocytic differentiation was demonstrated by conventional histology, immunocytochemistry, electron microscopy, and Western-blot analysis. Oncocytic meningiomas showed an aggressive behavior; recurrences were observed in three cases, and invasion of brain cortex was evident in other two cases.

Arachnoid cyst in the region of the fourth ventricle mimicking clinical picture of normal pressure hydrocephalus

Arachnoid cysts in the region of the fourth ventricle are rarely reported. Two cases with intraventricular arachnoid cysts (one in the fourth and one in the right lateral) manifesting normal pressure hydrocephalus have been described in the previous literature. Here we report a clinically similar case in which the cyst was wedged in cerebellar vermis and compressed the fourth ventricle. Slow enlargement of the cyst could explain the clinical picture. The removal of the cyst resulted in a marked improvement of the symptoms despite the lack of significant changes in ventricular size.

Glioependymal cyst of the cerebellopontine angle

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Sialorrhea from fourth ventricle hydrocephalus. Case report

The case of a 50-year-old man with tetraventricular hypertensive hydrocephalus is presented, remarkable for fourth ventricle dilatation. This patient showed a significant sialorrhea as the main symptom, which is quite unusual. This condition was successfully treated by cerebrospinal fluid diversion. The uncommon features of this case are summarized.

Orbital pain and unruptured carotid-posterior communicating artery aneurysms: the role of sensory fibers of the third cranial nerve

Intact aneurysms of the carotid siphon at the point of take-off of the posterior communicating artery may exhibit orbital pain, whether associated with oculomotor palsy or not as a warning symptom prior to rupture. In order to explain this symptom the hypothesis of a sensory pathway within the third cranial nerve, which is liable to compression by the enlarging aneurysm sac, has been investigated. Data from human autopsy material show evidence of sensory ganglion cells within the rootlets of the oculomotor nerve; furthermore, studies in animals prove that the third nerve contains sensory fibers which run proximally along the nerve bundles, enter the brainstem and reach the spinal trigeminal nucleus. These fibers come from the ophthalmic division of the fifth nerve and join the third nerve at the level of the lateral wall of the cavernous sinus. Although a number of questions remain to be solved, the presence of a sensory pattern within the third nerve could account for fronto-orbital pain from enlarging aneurysms impinging on the third nerve itself.

Multiple lesions in cerebral white matter in two young adults with thoracic extramedullary tumours

Cranial MRI showed multiple lesions in white matter that were thought to be consistent with multiple sclerosis in two young adults presenting with symptoms of progressive myelopathy. MRI of the cervicothoracic spine around one and two years after onset showed the myelopathy to be due to mid-thoracic tumours. The tumours (an extradural meningioma and intradural neuroma) were resected with complete resolution of myelopathy in one patient but no recovery in the other. Spinal MRI (or myelography) should be performed in young patients presenting with signs of progressive myelopathy even when cranial MRI shows a picture typical of multiple sclerosis.

Intracranial squamous cell carcinoma arising in remnant of extirpated epidermoid cyst

Development of a squamous cell carcinoma in an epidermoid cyst is rare. A case is presented in which such malignant change arose in the capsule remnants of an intracranial epidermoid removed 31 years previously. The limited literature dealing with this late sequela is summarized.

A hazard of craniotomy in the sitting position: the posterior compartment syndrome of the thigh. Case report

A bilateral posterior compartment syndrome of the thigh with a sciatic neuropathy in a patient following a craniotomy in the sitting position is described. The pathophysiology of the sciatic nerve dysfunction is discussed and the diagnostic value of computerized tomography is emphasized. Prompt decompression of the nerve is suggested.

Trigeminal neuralgia associated with contralateral intracranial tumour: a false localising sign caused by vascular compression? Report of two cases

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Slowly progressive ischemic stroke as first manifestation of essential thrombocythemia

We report a case of essential thrombocythemia, the only clinical manifestation of which consisted of neurologic symptoms, including anomic aphasia, tactile and painful hypesthesia in the right hand, headache, and Gerstmann syndrome, with a relatively benign and slowly progressive clinical course. Neuroradiologic examination disclosed a large ischemic area in the left temporoparietal region. Cerebral angiography revealed an occlusion of the cortical branches of the left middle cerebral artery with total sparing of the carotid vessel. These findings are discussed in relation to the possible pathogenetic mechanisms of the vascular occlusion due to abnormal platelet function in essential thrombocythemia.

Risk factors for the syndrome of ventricular enlargement with gait apraxia (idiopathic normal pressure hydrocephalus): a case-control study

A case-control study was performed to verify the association between the risk factors for cerebrovascular disease and the syndrome of ventricular enlargement with gait apraxia (VEGAS). This syndrome was defined on the basis of clinical and CT criteria alone; however, it may be representative of patients with idiopathic normal pressure hydrocephalus in whom gait disturbance is the initial symptom. Seventeen patients were matched for age and sex with one hospitalised and two general population controls. Among the risk factors considered we found a significant statistical association between VEGAS and hypertension (odds ratio = 3.14; p = 0.032), ischaemic heart disease (odds ratio = 4.20; p = 0.013), ECG ischaemic changes (odds ratio = 3.67; p = 0.029), low HDL-cholesterol levels (odds ratio = 3.75; p = 0.028) and diabetes (odds ratio = 6.00; p = 0.018). Our findings indicate that risk factors for cerebrovascular disease may play a role in the development of VEGAS.

Metastases of the spinal cord from remote neoplasms. Study of five cases

Five patients with acute or subacute myelopathy are reported in whom neuroradiologic imaging or open surgery showed an intrinsic spinal cord tumor. Histologic diagnosis was obtained either through direct spinal cord biopsy or after biopsy or removal of a former or concurrent intracranial metastasis. Carcinoma of "possible" gastrointestinal origin, oat-cell carcinoma, melanoma, and bronchogenic adenocarcinoma in two cases were demonstrated. The clinical course showed a devastating and irreversible deterioration of the neurological condition in all patients but one, who exhibited a mildly symptomatic disease. Our uncertainty with cases of intramedullary spinal cord metastasis resulted in a nonstandardized approach to these patients. The role of magnetic resonance imaging, the radiotherapeutic option, and the pertinent literature are briefly discussed.

Intracranial microvascular decompression for "cryptogenic" hemifacial spasm, trigeminal and glossopharyngeal neuralgia, paroxysmal vertigo and tinnitus: II. Clinical study and long-term follow up

20 patients who had undergone microvascular decompression for the treatment of "idiopathic" trigeminal neuralgia (9 cases), hemifacial spasm (7 cases), glossopharyngeal neuralgia (3 cases) and paroxysmal vertigo and tinnitus (1 case) were followed up for 25 months on average. Permanent relief of symptoms was observed in 19 (95%), with sparing of cranial nerve function. Analysis of the clinical data shows that the patients described in the present series did not differ from those considered to suffer from "idiopathic" cranial nerve dysfunction syndromes. The importance of vascular cross compression as etiological factor in such conditions is stressed and the pathophysiology discussed. The term "cryptogenic" applied to trigeminal neuralgia or hemifacial spasm thus needs revising. Lastly, the indications of microvascular decompression in the treatment of "cryptogenic" cranial nerve dysfunction syndromes are defined.

Intracranial microvascular decompression for "cryptogenic" hemifacial spasm, trigeminal and glossopharyngeal neuralgia, paroxysmal vertigo and tinnitus: I. Surgical technique and results

Intracranial microvascular decompression was performed in 21 out of 24 patients with hyperactive dysfunction of cranial nerves: 8 cases of hemifacial spasm, 12 of trigeminal neuralgia, 3 of glossopharyngeal neuralgia and 1 case of paroxysmal vertigo and tinnitus. In 21 cases an abnormal vascular loop was found to impinge on the root entry zone of the nerve in the brainstem. Dissection of this loop with decompression of the nerve resulted in long-lasting relief of symptoms in all but two patients who presented early recurrence; in one of these a second procedure was eventually successful. In two patients with trigeminal neuralgia a benign tumor of the cerebellopontine angle that had escaped preoperative diagnosis was present. Finally, in one case no compressive lesions were found. From the data of the literature and from our present experience microvascular decompression can be considered a safe as well as an effective procedure, affording a high success rate in conditions often or usually resistant to medical treatment and erroneously considered "idiopathic".

Delayed angiographic appearance of a large basilar aneurysm

A technically adequate four-vessel cerebral angiogram was normal on the first day after a typical episode of subarachnoid hemorrhage. The study was repeated 40 days later showing a large aneurysm of the basilar bifurcation. Hypothetically, the first attempt to visualize the aneurysm was negative due to early transitory thrombosis of the aneurysmal sac. In some cases of subarachnoid hemorrhage it is beneficial to repeat previously normal angiographic studies.

[Correlations between E.E.G. findings and intracranial pressure (ICP) during treatment of acute post-traumatic intracranial hypertension (preliminary report) (author's transl)]

An infusion of a 10% solution of Althesin was administered for treatment of acute post-traumatic intracranial hypertension. Six comatose patients, aged from 7 to 22 years, without neurosurgical lesions, were treated with doses of the compound varying from 40 to 400 ml per day for 1 to 6 days. Daily polygrahic recordings (E.E.G, E.M.G., E.K.G., respiration and I.C.P.) were made in all patients for periods of 4 to 8 hours. Doses lower than 0.12 ml/min. caused a slight reduction in I.C.P. in two patients, without variations in the E.E.G. Doses between 0.12 and 0.36 ml/min. provoked a reduction in I.C.P. in all patients, and the appearance of burst suppression in the E.E.G. in those patients with an "alternating" tracing only. Higher doses (0.36 to 0.72 ml/min.) caused a reduction in I.C.P. less than 50% in 5 of the 6 patients. Continuous slow wave tracings and border-line tracings showed less constant modifications. The reactivity of the I.C.P. and the E.E.G. to Althesin appears earlier and is more evident in patients with an alternating E.E.G. tracing and with pressure waves of the Lundberg type b. No side effects related to the use of barbiturates were noted after interrupting treatment.

[Correlations between intracranial pressure (I.C.P.) and EEG changes during traumatic coma (author's transl)]

A total of 55 polygraphic recording (ICP, EEG, EMG, EOG, Respiration, and ECG) were made in 20 comatose patients following cranial injuries, during the week after the injury. Whenever the ICP was stable, and without waves, and whatever the mean values were, the EEG tracing was slow, monomorphic, of large amplitude, and nonreactive. Each time that ICP recordings included Lundberg's B waves, the EEG tracings showed alternating bursts of slow waves and periods of rapid activity, with or without typical sleep patterns. The ICP increases each time there is flattening of the tracing and diminishes with the reappearance (spontaneous or provoked) of slow waves. The artificial respiration is not always involved in determining these phenomena.