The role of a virtual telephone clinic in the follow-up management of lateral skull base tumours.

OBJECTIVE: The purpose of this article was to determine the impact of employing a telephone clinic for follow-up of patients with stable lateral skull-base tumours. METHOD: An analysis of 1515 patients in the national lateral skull-base service was performed, and 148 patients enrolled in the telephone clinic to date were identified. The length of time that patients waited for results of their follow-up scans and the travel distance saved by patients not having to attend the hospital for their results was determined. RESULTS: The mean time from scan to receiving results was 30.5 ± 32 days, 14 days sooner than in the face-to-face group (p = 0.0016). The average round-trip distance travelled by patients to the hospital for results of their scans was 256 ± 131 km. CONCLUSION: The telephone clinic led to a significant reduction in time until patients received their scan results and helped reduce travel distance and clinic numbers in traditional face-to-face clinics.

Acute glucocorticoid deficiency and diabetes insipidus are common after acute traumatic brain injury and predict mortality.

CONTEXT: Published data demonstrates that hypopituitarism is common after traumatic brain injury (TBI). Hormone deficiencies are transient in many, but the natural history of the acute changes after TBI has not been documented. In addition, it is not clear whether there are any early parameters that accurately predict the development of permanent hypopituitarism. OBJECTIVES: There were 3 main objectives of this study: 1) to describe the natural history of plasma cortisol (PC) changes and sodium balance after TBI; 2) to identify whether acute hypocortisolemia or cranial diabetes insipidus (CDI) predict mortality; and 3) to identify whether the acute pituitary dysfunction predicts the development of chronic anterior hypopituitarism. DESIGN: Each TBI patient underwent sequential measurement of PC, plasma sodium, urine osmolality, and fluid balance after TBI. All other anterior pituitary hormones were measured on day 10 after TBI. The results from 15 surgical comparisons defined a PC less than 300 nmol/L as inappropriately low for an acutely ill patient. CDI was diagnosed according to standard criteria. Surviving TBI patients underwent dynamic anterior pituitary testing at least 6 months after TBI. SETTING: The patients were recruited from the Irish National Neurosurgery Centre. PATIENTS: One hundred sequential TBI patients were recruited. Fifteen patients admitted to Intensive Therapy Unit (ITU) after major surgery were recruited as comparison patients. MAIN OUTCOME MEASURES: PC in TBI patients was compared with that of comparison patients. The mortality rate was compared between TBI patients with and without acute hypocortisolemia. Results of follow-up dynamic pituitary testing were compared between those with and without acute hypocortisolemia. RESULTS: Most of the TBI patients (78%) developed inappropriately low PC after TBI. Low PC and CDI were predictive of mortality. Thirty-nine percent of the patients who had follow-up testing had at least 1 pituitary hormone deficit, all of whom had had previous acute hypocortisolemia or CDI. CONCLUSIONS: Acute hypocortisolemia and CDI are predictive of mortality and long-term pituitary deficits in TBI.

Acromegaly associated with gangliocytoma.

BACKGROUND: Acromegaly secondary to growth hormone-releasing hormone (GHRH) excess is rare. AIMS/CASE DESCRIPTION: We report two patients with acromegaly who were diagnosed with sellar gangliocytomas that were immunopositive for GHRH. Tumour tissue persisted after debulking surgery and in the second case this was associated with persistent growth hormone hypersecretion, successfully suppressed by a somatostatin analogue. CONCLUSIONS: The development of functional pituitary adenomas in association with sellar gangliocytomas is poorly understood. We present a brief discussion of the possible aetiology of these unusual pituitary tumours.

Incidence and pathophysiology of severe hyponatraemia in neurosurgical patients.

BACKGROUND: Hyponatraemia is a well-recognised complication of neurosurgical conditions, but the incidence and implications have not been well documented. OBJECTIVE: To define the incidence, pathophysiology and clinical implications of significant hyponatraemia in several neurosurgical conditions. METHODS: All patients admitted to the Irish National Neurosciences Centre at Beaumont Hospital, Dublin with traumatic brain injury, subarachnoid haemorrhage, intracranial neoplasm, pituitary disorders and spinal disorders who developed significant hyponatraemia (plasma sodium <130 mmol/l) from January 2002 to September 2003 were identified from computerised laboratory records. Data were collected by retrospective case note analysis. RESULTS: Hyponatraemia was more common in patients with pituitary disorders (5/81, 6.25%; p = 0.004), traumatic brain injury (44/457, 9.6%; p<0.001), intracranial neoplasm (56/355, 15.8%; p<0.001) and subarachnoid haemorrhage (62/316, 19.6%; p<0.001) than in those with spinal disorders (4/489, 0.81%). The pathophysiology of hyponatraemia was: syndrome of inappropriate antidiuretic hormone secretion (SIADH) in 116 cases (62%) (31 (16.6%) drug-associated), hypovolaemic hyponatraemia in 50 cases (26.7%) (which included patients with insufficient data to assign to the cerebral salt-wasting group (CSWS)), CSWS in nine cases (4.8%), intravenous fluids in seven cases (3.7%) and mixed SIADH/CSWS in five cases (2.7%). Hyponatraemic patients with cerebral irritation had significantly lower plasma sodium concentrations (mean (SD) 124.8 (0.34) mmol/l) than asymptomatic patients (126.6 (0.29) mmol/l) (p<0.0001). Hyponatraemic patients had a significantly longer hospital stay (median 19 days (interquartile range (IQR) 12-28)) than normonatraemic patients (median 12 days (IQR 10.5-15)) (p<0.001). CONCLUSIONS: Hyponatraemia is common in intracerebral disorders and is associated with a longer hospital stay. Cerebral irritation is associated with more severe hyponatraemia. SIADH is the most common cause of hyponatraemia and is often drug-associated.

Delayed diagnosis in a sight-threatening lesion.

BACKGROUND: Acute chiasmal compression has several aetiologies including pituitary apoplexy, a medical emergency caused by acute haemorrhagic or ischemic infarction in pituitary macroadenomas. Clinical diagnosis can often be difficult as the patient is frequently unaware of an existing adenoma. Delayed diagnosis may lead to increased morbidity and mortality. AIM: We describe a rarely presenting case report of acute chiasmal compression with unusual visual symptoms of hemifield slide, with initial delayed diagnosis. CONCLUSION: Knowledge of this infrequently presenting visual phenomenon may aid in rapid diagnosis, appropriate imaging and intervention leading to improved visual and systemic outcomes.

Supratentorial juvenile pilocytic astrocytoma in a young adult with Silver-Russell syndrome.

Silver-Russell syndrome is a rare genetically heterogeneous disorder in which patients demonstrate intrauterine and postnatal growth retardation, triangular facies, excessive sweating during early childhood, late closure of the anterior fontanelle and skeletal asymmetry. An association with malignancy exists and only one previous intracranial tumour has been reported, a craniopharyngioma. We report the first case of Silver-Russell syndrome associated with a supratentorial juvenile pilocytic astrocytoma.

Should patients with benign positional vertigo be imaged?

Unexpected intra-cranial pathology is unusually encountered in patients with BPV in the presence of a classically positive Hallpike's response and in the absence of any other neurological signs or symptoms. We carried out a retrospective review to assess the incidence of unexpected intra-cranial pathology in patients with a clinical diagnosis of benign positional vertigo (BPV) and to review the role of radiological imaging in these patients. 145 consecutive patients seen by the senior author with a diagnosis of posterior semi-circular canal BPV over a five-year period were reviewed. In the series of 63 patients who underwent MRI, two cases (3.2%) had cerebral aneurysms, one patient had an epidermoid cyst (1.58%) and one patient had a large right parietal arterio-venous malformation. We would conclude that possible warning signs exist that may alert the clinician to the possibility of unexpected intracranial pathology including failed response to the initial Epley manoeuvre or any asymmetry in hearing. Thus, we would advocate imaging be performed on this sub-group of patients with BPV.

Craniotomy with prosthetic heart valves: a clinical dilemma.

The authors report two cases of spontaneous intracranial haemorrhage after elective craniotomy for resection of cerebral tumour. Both patients had mechanical aortic valve prostheses and were on regular warfarin therapy. In both cases, warfarin therapy was discontinued 5 days prior to surgery and unfractionated heparin administered intravenously until 12 h before surgery. Both patients were re-anticoagulated with subcutaneous low molecular weight heparin within the first week postcraniotomy-both developed life-threatening intracranial haemorrhage requiring urgent evacuation. The authors emphasize the risk of re-anticoagulation without postoperative imaging and the disadvantages of therapeutic dose, low molecular weight heparin in the postoperative period.

Facial nerve schwannoma of the internal auditory canal.

BACKGROUND: Facial nerve schwannoma of the internal auditory canal is a very rare tumour. AIM: While Bell's palsy is the commonest cause of a facial paresis, more serious causes should be excluded if recovery is delayed. METHOD: A case report of a young man who presented with a long standing facial palsy. CONCLUSION: Any facial palsy that does not show evidence of recovery within six weeks should be investigated radiologically to exclude a tumour.

Paraganglioma of the cauda equina: a case report and literature review.

A 26-year-old man presented with left leg pain and progressive paraparesis. Imaging revealed a large intradural tumour compressing the cauda equina. The lesion was radically resected and histological analysis revealed it to be a paraganglioma. The clinical features of this rare tumour are described with a review of the literature.

Superficial siderosis of the central nervous system following cervical nerve root avulsion: the importance of early diagnosis and surgery.

Superficial siderosis (SS) of the central nervous system is an insidious, progressive, irreversible and debilitating neurological disorder caused by recurrent haemorrhage within the subarachnoid space. The subsequent deposition of haemorrhagic breakdown products in the spinal cord and nervous tissues leads to the loss of neurones and myelin, and to the development of a neurological deficit. In a small number of patients, the source of haemorrhage is related to traumatic cervical nerve root avulsion occurring several years prior to the onset of symptoms. Surgical ablation of the source has been shown to halt the progression of the disease, at least in the short term. We review the literature on SS secondary to cervical nerve root avulsion and report a further case in which surgical management was successful in halting disease progression. We emphasize that early detection and recognition of the initial non-progressive symptoms related to this poorly known disease, coupled with timely surgical management, minimizes the degree of neurological disability.

Idiopathic spinal cord hernia.

Idiopathic spinal cord hernia (ISCH) is a rare cause of slowly progressive spinal cord dysfunction. It is readily diagnosed on magnetic resonance imaging of the spine. The neurological deficit related to ISCH is often reversible once surgical exploration and reduction of the hernia is achieved. We present the case of a 37 year-old lady with a ventral ISCH at the T4 level. There was a significant post-operative improvement in her myelopathy post-operatively. ISCH should be considered in the differential diagnosis of progressive spinal cord neurological deficit.

The anatomical distribution of cerebral gliomas in mobile phone users.

We analysed the association between mobile phone use and the anatomical distribution of glial brain tumours in Irish neurosurgical patients. All patients with unilateral histologically proven glioma were enrolled over a 12 month period. We hypothesised that were a cellular phone to cause a glioma then it would do so on the dominant hand side. Fifty mobile phone users and twenty three non-users were identified. The vast majority of patients (69/73) were right handed and the right side of the brain was more common as the tumour site (48/73). Fisher's exact test revealed no statistical significance for glioma location based on the handedness of the patient in the mobile phone user group and location of the tumour in both user and non-user groups. We discuss our findings and the stable trend in the incidence of reported glioma cases.

Neurofibromatosis type 2--the importance of serial imaging of the brain and spinal cord.

Meningiomas and schwannomas are relatively common central nervous system neoplasms, but patients harbouring multiple meningiomas or schwannomas are rare. We present the case of a 27 year-old patient with Neurofibromatosis type 2 with multiple associated intracranial meningiomas and spinal cord neurofibromas at various levels. Patients with Neurofibromatosis type 2 should be followed up for life with serial magnetic resonance imaging of the brain and spinal cord to detect new and recurrent tumours at these sites.

An unusual cause for tinnitus.

Central giant cell granulomas of the skull base are uncommon entities. They usually present at the epiphyses of long bones such as the proximal femur and distal radius. Otological symptoms are not known as a common presenting symptom of giant cell granulomas.

Intracranial complications of acute frontal sinusitis.

Despite advances in the diagnosis and treatment of acute frontal sinusitis, there is still significant occurrence of intracranial complications. Urgent surgical evacuation of any intracranial collection is required; however, the surgical management of the associated sinusitis remains controversial. Ten patients presented to this department over a 12-month period with subdural empyema secondary to acute frontal sinusitis. Four patients had a coexisting Pott's puffy tumour and one patient had a periorbital abscess. Each patient was managed using a multidisciplinary approach. A frontal sinus trephine/drain +/- antral washout was performed at the same time as craniotomy with evacuation of the empyema. With this approach only two patients suffered long-term morbidity in our series, in the form of persistent neurological or cognitive deficit. No patient required a definitive sinus procedure. This study emphasizes the need for the early assessment and intervention of patients with an intracranial complication secondary to acute frontal sinusitis. Further assessment of the underlying sinus disease is indicated during outpatient follow up after the acute episode.

Traumatic bilateral internal carotid artery dissection following airbag deployment in a patient with fibromuscular dysplasia.

This case describes a 39-yr-old male, presenting with left hemiplegia after a road traffic accident involving frontal deceleration and airbag deployment. Brain computerized tomography (CT) scan revealed a right parietal lobe infarct. Contrast angiography demonstrated bilateral internal carotid artery dissection and fibromuscular dysplasia. The patient was treated with systemic heparinization. Neurological improvement, evidenced by full return of touch sensation, proprioception and nociception began 10 days after the injury. To our knowledge, this is the first case report of carotid artery dissection associated with airbag deployment. Forced neck extension in such settings may result in carotid artery dissection because of shear force injury at the junction of the extracranial and intrapetrous segments of the vessel. Clinicians should consider carotid artery injury when deterioration in neurological status occurs after airbag deployment. We propose that the risk of carotid artery dissection was increased by the presence of fibromuscular dysplasia.

Benign glandular peripheral nerve sheath tumor of the seventh and eighth cranial nerve complex.

A unique, deep-seated, benign, glandular peripheral nerve sheath tumor (PNST) of the cerebellopontine angle is described. The tumor arose from the seventh and eighth cranial nerve complex in a 15-year-old boy without neurofibromatosis. Histologically, benign glands were embedded in a bland spindle cell stroma. The epithelial cells were immunoreactive for CAM 5.2, and focally for chromogranin. The spindle cells were positive for S100P. The benign glandular PNST unassociated with neurofibromatosis is a controversial entity. The superficial location of most reported cases has made it difficult to exclude entrapped adnexae as a source for the glands. This tumor was separate from the internal auditory meatus on MRI scan, the most likely source of entrapped glands at this site. This case is the first report of a deep-seated, benign, glandular peripheral nerve sheath tumor. It suggests that glandular differentiation in PNSTs, while unusual, is not synonymous with neurofibromatosis or malignancy.