Preventing damage to miniature-loudspeaker by means of dynamic detection of excessive diaphragm displacement

The rapid development of consumer electronics and the extensive use of mobile devices require the ample use of miniature-loudspeakers for audio applications. The demand for better sound pushes manufacturers to design digital signal processing (DSP) chips (smart amplifiers), which in turn could cause unpleasant sound due to distortion and parameter nonlinearity or transducer damage caused by large diaphragm excursion or voice-coil (VC) burn. This article presents a methodology for nonlinear parameter estimation using an inverse method and displacement limiter for large VC displacement-dependent transducer damage prevention. A set of transduction equations is employed to inversely determine parameters using a polynomial expression. The appropriate selection of an objective function incorporating the unknown vector of nonlinear parameters leads to the adjoint problem that requires a gradient solution. A numerical solver is provided to obtain the VC displacement, current, and derivatives using a robust hybrid spline differential method. The dynamic limiter is proposed to control the peak values of the VC velocity so as to limit an excessive displacement which prevents impulsive damage to the receiver and further application of the DSP board. Numerical and experimental results indicate that the proposed method has high efficiency and can be widely used in transducer applications.

Preparation and thermal studies on tetranitrodibenzo tetraazapentalene (TACOT): a thermally stable high explosive

Thermally stable high explosive, tetranitro-2,3,5,6-dibenzo-1,3a,4,6a-tetraazapentalene (TACOT) was synthesized and characterized during this work. Thermo analytical techniques (TG and DSC) were applied to study the thermal decomposition behaviour of TACOT in comparison with benchmark thermally stable high explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). Kinetic parameters such as reaction order, activation energy and pre-exponential factors were computed from the thermal data. The activation energy for TACOT (292 kJ/mol) was found 1.5 times to that of TATB (200 kJ/mol), which can account for its higher thermal stability and can be attributed to pentalene moiety in the former.

Synthesis, characterization and thermolysis studies on triazole and tetrazole based high nitrogen content high energy materials

This paper reports the synthesis, characterisation and thermolysis studies of hydrazinium azotetrazolate (HAZ) and 1,1'-dinitro-3,3'-azo-1,2,4-triazole (N-DNAT). TGA and DSC results suggested that HAZ decomposes in the range of 150-180 degrees C and N-DNAT in the range of 160-170 degrees C, respectively. The pattern of decomposition of HAZ dihydrate and N-DNAT has been predicted with the help of pyrolysis GC/MS technique and a probable decomposition mechanism has been proposed. The theoretically predicted performance data suggests the potential nature of HAZ and N-DNAT for their use in propellant/explosive as well as in gas generator formulations.

Subgaleal migration of a ventriculoperitoneal shunt

Blockage of a ventriculoperitoneal (VP) shunt is very common. Here, we describe an unusual case of shunt blockage in an infant. He was shunted for hydrocephalus associated with a Dandy-Walker malformation diagnosed at birth. At surgery, the entire VP shunt was found to have migrated into the subgaleal space, which clinically presented as shunt obstruction. We suggest techniques to avoid this rare, but preventable, complication of shunt surgery.

Choroid plexus papilloma of the posterior third ventricle during infancy & childhood: report of two cases with management morbidities

We report two cases of posterior third ventricular choroid plexus papilloma, one in an 8-month-old infant and another in a two-year-old child. These cases presented with features of obstructive hydrocephalus. Both these patients underwent a ventriculo-peritoneal (VP) shunt surgery prior to the tumor excision. Following the VP shunt surgery both patients developed ascitis requiring exteriorization of the abdominal end of the shunt. There was a clear proof of CSF overproduction: 1400-1500 ml/day in the eight-month-old infant and 900-1200 ml/day in the two-year-old child. In the former it was transient and could be treated with revision of the VP shunt whereas in the second case a ventriculo-arterial shunt had to be done. In the second case a staged reduction cranioplasty was also performed for an enormously enlarged head (head circumference--74 cm). Interesting clinical and radiological findings and useful management strategies are described.

Angiolipoma of the right inferior colliculus: a rare central cause of hearing loss and limb ataxia

Intracranial angiolipomas are rare entities and are infrequently symptomatic. These benign lesions are adherent to the surrounding neurovascular structures as they share the same blood supply, which limits their resectability, and impose a possibility of persistence of symptoms. However, due to recent advancements in the neuro-radiological fields and microneurosurgical techniques it has been possible to localise precisely and excise these lesions with low morbidity and mortality. The authors present an interesting rare case of intracranial angiolipoma of the right inferior colliculus situated in the quadrigeminal plate cistern. The patient had presented with ipsilateral hearing loss and upper limb ataxia. Interesting clinical findings, neuro-imaging studies and peroperative features are presented and discussed along with a brief review of the literature.

Intracranial migration of Foley catheter--an unusual complication

Profuse nasal bleeding in cases of severe head injury is mostly associated with facial and skull base fractures and various methods have been tried to control such bleeding. Anterior nasal packing, producing a tamponade effect with a Foley catheter and other inflatable balloon devices are time proven methods. We describe a case of severe head injury with such fractures where a Foley catheter tamponade was attempted to control the severe nasal bleeding and the CT brain scan revealed inadvertent malposition of the catheter into the cranial cavity. This rare entity is described to highlight the potential danger associated with a proven method of controlling severe nasal bleeding and suggestions are outlined as to how to avoid such a mishap, along with a brief review of the literature.

Sudden bilateral foot drop: an unusual presentation of lumbar disc prolapse

Bilateral acute foot drop is reported in a 30-year-old healthy male. He presented with a 7-day history of sudden severe backache, radiating to both the lower limbs and 1-day history of sudden bilateral ankle weakness that progressed to bilateral foot drop within 6 hours. He also developed retention of urine. Investigations revealed a large central disc prolapse at L3-4 with significant canal stenosis at that level. Following surgery the patient had progressive improvement.

Long term outcome in patients with severe head injury and bilateral fixed dilated pupils

Patients with severe head injury with bilateral dilated unreactive pupils are considered to have a grave prognosis. Hence proper planning and aggressive management becomes mandatory for achieving good results. We present the outcome of consecutive 166 patients with severe head injury, admitted between January 1996 and December 2000 and analysed retrospectively. All the patients had an initial GCS of 8 or less and post resuscitation bilateral dilated unreactive pupils. Our aim was to analyze the long term outcome in these patients and identify the other significant prognostic factors. Of the 166 patients, 42 (25.30%) had a functional outcome (good recovery in 10.24%, moderate disability in 15.06%), and 124 (74.69%) had a poor outcome (death in 58.43% and severe disability in 16.26% of cases). There were 45 patients with polytrauma and 24 of these patients (53.33%) succumbed to the injuries. Obliteration of the basal cisterns and contusion were the common CT scan findings. Factors adversely affecting the survival included age of the patient, polytrauma with shock, initial GCS of 3 or 4, and compression of the basal cisterns on the initial CT scans. At follow up, most of the patients with a functional outcome showed a significant improvement in their motor function but continued to have neuro-behavioral and cognitive deficits.

Pediatric giant cell granuloma of the temporal bone: a case report and brief review of the literature

Giant cell granuloma of the skull base is a distinct rare clinicopathologic lesion, which progressively destroys the involved bone. It causes increased intracranial pressure and mass effect on the brain. Histologically it may mimic an aneurysmal bone cyst, giant cell tumour and the brown tumour of hyperparathyroidism. Although cited by some authors, the role of trauma in its aetiology is still considered controversial. Authors present an interesting case of a 12 year old Omani boy who sustained a cricket bat injury to his right temporal region from which he initially recovered but later on progressively developed vertigo, tinnitus, right hearing loss and a mild right facial weakness. Computed tomography (CT scan) and Magnetic resonance imaging (MR scan) revealed a large destructive lesion of the temporal bone. Microsurgical excision was curative. Interesting clinicoradiological findings are presented with a brief review of the literature.

Symptomatic cranial fibrous dysplasias: clinico-radiological analysis in a series of eight operative cases with follow-up results

Cranial fibrous dysplasias are rare and comprise less than one percent of all primary bone lesions. These painless progressively expanding destructive bone swellings produce cosmetic deformities (commonest), sino-orbital and auditive complications (less common), peripheral compressive cranial neuropathies (uncommon) and compressive central neurological manifestations (rarest). Until recently some of the primary dysplastic skull base lesions were either treated expectantly or excised incompletely. In a significant percentage of cases, these lesions were considered inaccessible. However, with the development of modern neuro-imaging (CT and MRI) and the applications of current skull base approaches, the more aggressive and radical surgical procedures are being undertaken, with a significant improvement in overall outcome. We present a series of 8 cases of fibrous dysplasia in the age group of 10-33 years with a mean age of 19.75 years. Four cases each had monostotic type and polyostotic type. All patients presented with mild to moderate headaches, and seven cases with some form of cosmetic deformity. In 4 patients there was a unilateral proptosis, while only two had visual deterioration. One patient had anosmia and one hearing impairment. In one case fibrous dysplasia was hemicranial, and in another case the disease was pancranial. Neuro-imaging studies have well delineated the extent of the lesions. In two patients with unilateral fronto-orbital fibrous dysplasia, the removal of dysplastic bone, autoclaving and remodeling and replacement were performed. In two patients of sphenoidal wing fibrous dysplasia a total excision was possible. In the remaining four patients, a partial excision was performed. Overall outcome was good. There was no mortality. One patient had recurrent post-operative extradural haematomas. The authors present the results of an analysis of eight surgically treated cases of symptomatic cranial fibrous dysplasias along with their long-term outcome and the lessons learnt from this series.

An unusual posterior mediastinal lipoblastoma with spinal epidural extension presenting as a painful suprascapular swelling: case report and a brief review of the literature

Lipoblastoma is a rare benign pediatric neoplasm of fetal-embryonal fat with little risk of recurrence following total microsurgical excision, but it may progress to local invasion or infiltration if not treated surgically. No adjuvant therapies are usually necessary once the tumor is excised. It is best diagnosed on histopathological studies following excision. An unusual posterior mediastinal lipoblastoma in a 2-year-old Omani girl with spinal epidural extension clinically manifested as a progressive painful suprascapular swelling is reported. It was initially construed to be a benign lipoma, but progressively increasing pain and mild imbalance whilst walking with a tendency to fall on the right side prompted neurosurgical referral and eventual total excision without any added morbidity. Interesting clinical and neuroimaging (CT & MRI) findings are presented and discussed, with a brief review of the literature.

Rathke's cleft cyst presenting as pituitary apoplexy

Sellar lesions mainly constitute pituitary adenomas, craniopharyngiomas and benign cysts. Rathke's pouch cyst is a developmental sellar and/or suprasellar cystic lesion lined by a single layer of ciliated cuboidal or columnar epithelium, which rarely be comes symptomatic. The authors present an interesting case of intrasellar Rathke's pouch cyst, with a presenting feature of acute pituitary apoplexy. This was a 19 year old healthy male who had developed sudden headache and visual disturbance. Neuro-radiological imaging revealed a mass in the sella. Via transsphenoidal approach a haemorrhagic intrasellar cystic lesion was removed and was confirmed as a haemorrhagic Rathke's cleft cyst by histopathological examination. Interesting clinical presentations and the neuroimaging findings are described and discussed.

Intracranial Salmonella infections: meningitis, subdural collections and brain abscess. A series of six surgically managed cases with follow-up results

Focal intracranial infections due to Salmonella are rare. So far, around 80 cases have been reported in the world literature. The authors present their experience of 6 cases of intracranial Salmonella infections, mainly subdural empyema in 5 and effusion in 1. In 1 case, subdural empyema was bilateral, and in another case, there was an associated brain abscess. Positive blood cultures and positive Widal tests were noticed in 2 patients each. Early diagnosis and prompt evacuation of subdural collections and brain abscess and antibiotic therapy lead to satisfactory results. This study suggests that a high index of suspicion, early diagnosis and quick evacuation lead to success; this point is highlighted with the help of a review of the literature.

Craniospinal giant cell tumors: clinicoradiological analysis in a series of 11 cases

Primary craniospinal giant cell tumors are rare (5-15% of all giant cell tumors), locally destructive bone lesions which are generally not associated with Paget's disease. Clinical behavior of the craniospinal giant cell tumor (GCT) is unpredictable but often very aggressive and therefore optimal management of the lesions remains controversial. Wide resection of the involved bone is required, preferably with a wide margin of normal tissue, which may be difficult to achieve in the craniospinal region. The authors analysed a series of 11 patients, which included five cases of cranial and six cases of spinal GCTs. Their ages ranged from 12 to 46 years with a male preponderance. In the five cranial cases, all the tumors involved the skull base, three involved the spheno - ethmoidal region and in two cases the petroclival region was involved. Common presenting symptoms were frontotemporal swelling, epistaxis, local pain and neurological deficits attributable to the neurovascular compression. Proptosis, visual loss, nasal mass and cranial nerve involvement were the common findings. In the six patients with spinal lesions (one cervical, four thoracic and one thoracolumbar), local pain, progressive sensory motor deficits and bladder involvement were common presentations. Neuroimaging studies were performed in various combinations for preoperative evaluation and surgical planning. In cranial cases, multidisciplinary approaches were used to perform a near total or a total excision. In the spinal GCTs, only a partial excision was possible. Postoperative radiotherapy was delivered in ten patients. Histopathological studies were diagnostic. All patients were followed up for periods ranging from one to 10 years, with a mean of 2 years and 3 months. No significant increase in the residual tumor or recurrences, as seen on periodic neuroimaging studies, were noted during their follow-up period.

Congenital intra-extracranial dumbbell schwannoma of temporal fossa unassociated with any major cranial nerve

Intracranial schwannomas commonly arise from the vestibular nerve and less commonly from other cranial nerves. On rare occasions, they may be intraparenchymatous, intraventricularor intrasellar. However, the occurrence of a congenital solitary intracranial extradural schwannoma unrelated to any cranial nerve in the absence of von Recklinghausan's syndrome is exceptional. The authors report a unique, heretofore unreported case of a congenital temporal extradural schwannoma, unassociated with any known cranial nerve and with a transcranial extension presenting as a temporal fossa mass since birth in a 16-year-old female patient. Total resection of this tumour was uncomplicated. A brief review of the relevant literature is presented.

Trans-sellar trans-sphenoidal encephaloceles: report of two cases

Trans-sphenoidal encephaloceles are rare entities. Only about 20 such cases have been reported in the world literature to date. Among these, the trans-sellar variety is rarest (five cases). We present two cases of trans-sellar trans-sphenoidal encephaloceles seen over the last 12 years. The first case was a 5 month old male infant presenting with nasal obstruction and a mass in the mouth. The second case was a 14 year old boy presenting with chronic nasal obstruction since early childhood. In the first case, the mass was coming to the mouth through the split palate. In the second case, the mass could be seen in the posterior half of the nose by rhinoscopy. The computed tomography scans including coronal and sagittal reconstructions had revealed trans-sellar trans-sphenoid encephaloceles in both the patients. The magnetic resonance imaging in the second case showed the cavity and the structures of the floor of the third ventricle forming the main fundal contents. The magnetic resonance angiography revealed dipping of the ectatic anterior cerebral arteries in the neck of the encephalocele sac in this case. Extracranial trans-palatal approach and the repair of encephalocele was done in the first case with the palatal reconstruction at the same sitting. In the second patient, a trans-nasal approach with bilateral maxillotomies was performed to repair the encephalocele, and the skull base defect was repaired by a split rib graft, which was fixed with mini-plate and screws posteriorly at the clivus and anteriorly at the anterior edge of the bony defect. The cleft lip and hypertelorism also were corrected at the same sitting. Our first case had CSF leak on the 10th postoperative day and developed fulminant meningitis, despite appropriate antibiotics, and succumbed. The second patient had a good postoperative recovery and a satisfactory follow up for 2 years.

An unusual presentation of an intra-parenchymatous frontal yolk sac tumour : case report

Yolk sac tumours are rare conditions among the germ cell tumours. Intracerebral germ cell tumours are exceedingly rare. A 15 year old girl presenting with a one week history of raised intracranial pressure is described. She had bilateral papilloedema and a right 6th nerve palsy. CT scan showed an intra-parenchymatous right frontal ring enhancing lesion of 2 cms diameter. The patient underwent microsurgical total excision of the tumour, followed by chemotherapy. She was asymptomatic at three years following surgery.

Hypersensitivity to glucocorticoids in patients with raised ICP : report of two cases

Corticosteroids are widely used in patients with raised intracranial pressure associated with cerebral neoplasms, cerebral vascular malformations, cerebral ischaemia and benign intracranial hypertension. In general clinical practice, anti-allergic, anti-inflammatory and immuno-suppressive properties of corticosteroids are commonly utilised in the management of allergic and immunological diseases. However in exceptionally rare circumstances, steroids may be the cause of hypersensitive reactions. Authors report two patients with raised intracranial pressure who developed steroid hypersensitivity. A review of the relevant literature is discussed.

Fatal rhino-orbito-cerebral mucormycosis in an apparently normal host: case report and literature review

Fungal infections of the central nervous system (CNS) are fortunately rare but remain challenging problems occurring mostly in immunocompromised individuals, with protean manifestations, unpredictable course and unfavorable outcome in many cases despite aggressive neurosurgical intervention and recent antifungal drugs. Rhino-orbito-cerebral mucormycosis is a potentially lethal opportunistic fungal infection with rapid progression and high mortality. Its pathogenic nature becomes evident when the patient's general resistance is compromised. We present a case of an invasive rhino-orbito-cerebral mucormycosis in an apparently normal adult who initially developed mild paranasal sinusitis and later developed status epilepticus and despite an aggressive management died. Interesting clinical, neuroimaging and histological findings are described, and the possibility of fatal mucormycosis in an apparently normal host is highlighted.

Vagal schwannoma of the cerebello-medullary cistern presenting with hoarseness and intractable tinnitus: a rare case of intra-operative bradycardia and cardiac asystole

Schwannomas arising from the lower cranial nerves (IX-XI) are rare, constituting only 3% of all intracranial schwannomas unassociated with neurofibromatosis. A great majority of these tumours present as jugular foramen lesions and less commonly they occur along the extracranial course of these nerves. An intracisternal location is extremely rare. We report a case of vagal schwannoma purely in the cerebello-medullary cistern causing distortion of the medulla oblongata. Total microsurgical excision of this tumor, arising from one of the rootlets of the vagus nerve, was achieved with preservation of the 9th, 10th and 11th cranial nerves.The intraoperative course was complicated by two episodes of complete cardiac asystole, each lasting for 4(s), and six episodes of severe bradycardia. The patient was relieved of his intractable tinnitus but continued to have a hoarse voice due to an ipsilateral partial vocal cord palsy.

CT stereotaxy guided lateral trans-cerebellar programmable fourth ventriculo-peritoneal shunting for symptomatic trapped fourth ventricle

A trapped fourth ventricle is a rare clinico-radiological entity producing symptoms suggestive of a progressive posterior fossa mass lesion. It is mainly reported in children as a late complication of lateral ventricular shunting to relieve infantile post-meningitic or post-hemorrhagic hydrocephalus. Optional treatment of the trapped fourth ventricle remains controversial. Placement of fourth ventricular shunting via a conventional midline approach can be fraught with complications in about 40% of the patients. Authors report a successful CT Stereotaxy guided high pressure (80 mm H(2)O) programmable fourth ventriculo-peritoneal shunting via a lateral trans-cerebellar approach in a 14-year-old girl with a trapped fourth ventricle, which occurred as a late complication of ventriculo-peritoneal shunting in her infancy. Her preoperative symptoms of raised intracranial pressure, bobble-head doll syndrome and bilateral abducens palsies completely improved following the surgery. Lateral trans-cerebellar stereotactic placement of the fourth ventricular catheter and the use of high-pressure (low flow) programmable shunt (to avoid complications associated with over drainage) are beneficial in some patients with trapped fourth ventricle.

Pharyngeal perforation and spontaneous extrusion of the cervical graft with its fixation device: a late complication of C2-C3 fusion via anterior approach

Stabilisation of the fracture-dislocation of the cervical spine is achieved effectively by anterior or posterior or combined methods with attendant short and long term benefits, risks and complications associated with each procedure. Recently anterior methods have gained wider acceptance. A variety of preoperative and postoperative complications associated with anterior cervical fusion are well recognised. However, the delayed pharyngeal or oesophageal perforation is a rare, serious and life threatening complication of an anterior cervical internal fusion.The authors report a case of delayed pharyngeal perforation and spontaneous extrusion of the C2-C3 graft with its fixation device. After coughing out the entire gamet of the graft with the fixation pin, the patient was relieved of excruciating pain and dysphagia and had no significant morbidity thereafter over a 12-year follow up period. Relevant aspects are discussed with a review of the pertinent literature.

Sciatica due to malignant nerve sheath tumour of sciatic nerve in the thigh

Malignant peripheral nerve sheath tumour (MPNST) is a rare malignant neoplasm arising from the supportive non-neural component of the peripheral nerves. An unusual case of pain and weakness of the foot and calf muscles due to a giant MPNST of the sciatic nerve in the posterior compartment of the thigh is presented. The patient was already investigated as a case of sciatica due to a lumbar disc disease with a negative magnetic resonance imaging and then unsuccessfully operated elsewhere twice, with a misdiagnosis of tarsal tunnel syndrome. Neurosurgical referral prompted a diagnostic magnetic resonance study of the thigh, revealing the lesion, which was completely excised microsurgically with total relief in the pain and partial improvement in the weakness and sensations in the sole of the foot.

Giant ependymal cyst of the temporal horn -- an unusual presentation. Case report with review of the literature

Primary benign cystic lesions in the brain are uncommon. However, extracerebral cysts like arachnoid cyst, epidermoid cyst and craniopharyngiomas are fairly common lesions. Also, colloid cyst in the third ventricle, dermoid cyst and endodermal cyst in the extracerebral location are not uncommon. On the contrary, intraventricular ependymal and choroidal cysts in the intraventricular location are infrequent. Surgical intervention is warranted in cysts, which produce a mass effect and raised intracranial pressure. We present an interesting case of a giant intraventricular ependymal cyst in the temporal horn in a 14-year-old boy, who presented with recent onset of headaches and epilepsy. He also had long-standing progressive proptosis of the left eye and left temporal bossing. Excision of this cystic lesion was curative. Interesting clinical and neuroimaging features are presented.

Solitary skull metastasis from mucoepidermoid mimicking a parotid tumour

Metastatic parotid tumours in the skull are very rare. An interesting case of a mucoepidermoid parotid tumour metastasizing to the skull vault is described in a patient who had previously been operated for a pituitary adenoma 20 years back with no post operative radiotherapy; however, she required hormonal supplementation therapy. She underwent an operation for a parotid tumour 7 years ago and received postoperative radiotherapy for the parotid tumour away from the site of the skull metastases. No local recurrence of the parotid tumour was noted. The initial diagnosis was that of a solitary intradiploic meningioma. Interesting clinico-radiological findings are presented.

Spinal cord and cauda equina compression in 'DISH'

Diffuse idiopathic skeletal hyperostosis (DISH) has long been regarded as a benign asymptomatic clinical entity with an innocuous clinical course. Precise information is lacking in the world literature. Authors report the results of a retrospective analysis of 74 cases of DISH. Eleven patients presented with progressive spinal cord or cauda equina compression. In nine cases ossified posterior longitudinal ligament (OPLL) and in two cases ossified ligamentum flavum (OLF) were primarily responsible. Surgically treated patients (eight) had far better outcome as compared to the patients managed conservatively, as they had refused surgery. 'DISH' is neither a benign condition, nor it always runs a innocuous clinical course. In fact, in about 15% of the cases, serious neurological manifestations occur, which may require a major neurosurgical intervention.

Cranio-spinal enterogenous cysts: clinico-radiological analysis in a series of ten cases

Enterogenous cysts are rare congenital lesions resulting from dysgenesis during the third embryonic week at the time of notochord development and the transitory existence of the neurenteric canal. Enterogenous cysts are usually lined by mucus secreting epithelium resembling that of the gastrointestinal tract. The inclusion of the endodermal elements in the spinal canal may produce extradural, intradural extramedullary or intradural intramedullary cystic lesions. The endodermal inclusions producing cysts in the intracranial compartment are extremely rare, especially in the supratentorial region. Plain X-rays may show concomitant cranio-spinal anomalies. However, CT and MRI scans show better definition and characterisation. Total excision is the procedure of choice in these benign cysts with favourable long term prognosis. Approximately 100 histologically proven cases have been described, with a few exceptions, as isolated case reports the authors report a detailed analysis of the clinico-radiological aspects of a series of ten patients with cranio-spinal enterogenous cysts with a review of the literature.

Primary orbito-cranial adenoid cystic carcinoma with torcular metastasis: a case report and review of the literature

Adenoid cystic carcinoma is a rare neoplasm arising from the exocrine glands such as salivary glands, lachrymal glands, upper respiratory tract, breast or uterine cervix. Intracranial involvement is commonly from direct skull base involvement, although metastasis may rarely be seen. The predisposition of the adenoid cystic carcinoma for perineural and perivascular invasion is the prime reason for the locally invasive character of the tumour, often extending into the cranium via foramina at the skull base. The authors report a case of primary orbito-cranial extradural adenoid cystic carcinoma and cranial metastasis away from the primary site. This patient initially had a local excision, and later an exenteration of the right eye followed by with radiotherapy. Within months she presented with an extradural cranial recurrence, distant torcular metastasis without any neurological deficit. Craniotomy and radical excision was undertaken as these tumours have slow growth rates, and long term survival of the se patients even in the presence of local recurrence and metastasis has been well documented.

Congenital and late-onset primary haemangiomas of the temporalis muscle: case report

We report on two patients with haemangiomas of the temporalis muscle, one congenital and one of late onset, which were diagnosed on computed tomography. Both were resected successfully and both patients are well with no signs of recurrence 3(1/2) years and 18 months later, respectively.

Schwannoma of the suprascapular nerve presenting with atypical neuralgia: case report and review of the literature

Compressive lesions of the suprascapular nerve produce weakness and atrophy of the supra- and infraspinatus muscles and a poorly defined aching pain along the posterior aspect of the shoulder joint and the adjacent scapula. Entrapment neuropathy of the suprascapular nerve is fairly common whereas tumorous lesions are rare; among the latter ganglion cysts are frequently seen. An isolated solitary schwannoma of the suprascapular nerve presenting with atypical neuralgic pain is exceptional. The location of a schwannoma under the firm deep cervical fascia in the posterior triangle of the neck is implicated in the genesis of neuralgic pains mimicking the suprascapular entrapment syndrome. One such case is reported with discussion of the relevant clinical features.

Symptomatic epineural ganglion cyst of the ulnar nerve in the cubital tunnel: a case report and brief review of the literature

An unusual case of pain and weakness in the hand and forearm due to a ganglion cyst of the ulnar nerve at the elbow is presented. The patient was managed initially as a case of cervical disc disease and cervical spondylosis and later as a case of carpal tunnel syndrome at an another institution. Cervical radiography and cervical magnetic resonance imaging scans were inconclusive. Neurosurgical referral revealed tenderness at the right cubital tunnel, weakness of the right hand and forearm muscles, and sensory deficit along the medial border of the forearm and the hand. The diagnosis of ulnar nerve compression at the elbow was made. Nerve conduction studies of the ulnar nerve at the elbow confirmed the diagnosis. A ganglion cyst of the ulnar nerve was excised microsurgically with a complete postoperative sensory motor recovery.

Symptomatic ependymal cysts of the perimesencephalic and cerebello-pontine angle cisterns

Primary intracranial ependymal cysts are extremely rare. These are congenital, benign ependyma lined, commonly intraparenchymal and uncommonly extraparenchymal cysts in leptomeningeal location of variable size seen in the adult life. The authors report two cases of symptomatic ependymal cysts: one in the perimesencephalic cistern in a 10-month-old infant presenting with delayed mile stones and another in the cerebello-pontine cistern in a morbidly obese 35-year-old woman with known benign intracranial hypertension now presenting with hemifacial spasm. Neurosurgical intervention was curative in both cases. Interesting clinical, radiological and histological features are presented and discussed.

Gluteal neuralgia - unusual presentation in an adult with intrasacral meningocele: a case report and review of literature

A nineteen year old man with intrasacral meningocele is reported, who presented with long standing episodic gluteal pain and progressive muscle wasting. Magnetic resonance imaging established the diagnosis. Surgical excision relieved the pain but muscle wasting persisted. Pertinent literature is reviewed.

Endodermal cyst of septum pellucidum and pregnancy: a case report

BACKGROUND

Endodermal or Neurenteric cysts are commonly found in spine. Their intracranial occurrence is rare and such a cyst in the septum pellucidum is exceptional.

METHOD

We report a woman, with 33 week pregnancy, presenting in a semiconscious state due to raised intracranial pressure (ICP) due to hydrocephalus caused by a large lesion in the septum pellucidum. Computed tomography (CT) revealed the lesion which was better characterised by the Magnetic Resonance Imaging (MRI). First baby was delivered by LSCS and bilateral ventriculo-peritoneal shunts were inserted; and later on the cyst was excised.

RESULT

There was full neurological recovery following the insertion of VP shunt. After excision of cyst cerebrospinal fluid (CSF) pathway was established and shunts could be removed. Post-operative period was complicated by septic ventriculitis. Eventually patient was discharged home in excellent condition.

CONCLUSION

Endodermal cyst of septum pellucidum is an uncommon condition. Such lesions may be large when revealed, good outcome is expected after surgical excision.

Neonatal cervical osteomyelitis with paraspinal abscess and Erb's palsy. A case report and brief review of the literature

An unusual case of pyogenic cervical osteomyelitis is reported in a newborn who immediately after birth had no movements in the left shoulder. There was a fullness in the left cervical region. Left Erb's palsy due to an unrecognized birth trauma was diagnosed in a peripheral hospital. Later, the child developed fever and a significant swelling in the left cervical region. On transfer to our institution, the X-rays of the cervical spine, ultrasound and computed tomography (CT) established the diagnosis of C(6) cervical osteomyelitis and paraspinal abscess which extended to the posterior triangle of the neck. The abscess was drained, and the lamina and lateral mass of the C(6) vertebra were debrided. Staphylococcus aureus was grown from the pus. The patient was put on long-term antibiotics to which he responded very well, and he became asymptomatic. In the immediate post-operative period, some movements at the left shoulder were noted, and at 6-month follow-up in the out-patient clinic, the child was virtually normal with near-complete regeneration of the C(6) lamina and lateral mass.

Frontal intraosseous cryptic hemangioma presenting with supraorbital neuralgia

Primary intraosseous cranial hemangiomas are rare benign tumors comprising 0.2% of all osseous neoplasms. Symptomatic cranial cryptic hemangiomas are extremely rare. We report the case of a 43-year-old man with a cryptic hemangioma of the superior orbital rim. Radiological investigations revealed it to be an intraosseous cryptic mass which was totally excised and the supraorbital nerve was decompressed, relieving the patient of his symptoms. Histopathology showed features of an intraosseous hemangioma.

Symptomatic calcified subdural hematomas

Two unique cases of chronic calcified subdural hematomas are reported in children as a long-term complication of a ventriculoperitoneal shunt. Both the patients had undergone shunt procedures in infancy for congenital hydrocephalus. In one patient, the cause of the hydrocephalus was aqueduct stenosis, while in the second patient, a lumbar meningomyelocele was associated with hydrocephalus. In both these patients, a ventriculoperitoneal shunt was done in infancy. In one of them, following the shunt surgery, a bilateral subdural collection was noticed which required burr hole evacuation. Both the patients remained asymptomatic for 9 years, when they presented to our center with acute raised intracranial pressure and contralateral hemiparesis. Both the patients had a relatively short history and had altered sensorium at admission. Surprisingly, in both the patients, the CT scan showed significant mass effect producing calcified subdural hematomas. The shunt systems were found to be working well at surgery. Craniotomy and excision of the calcified subdural hematomas was undertaken. Postoperatively, the patients showed satisfactory recovery, and at discharge the patients were doing well. At the follow-up at the outpatient clinic, the patients were asymptomatic.