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Biomedical subjects

M K Tewari

Publications and source records attributed to M K Tewari.

At least 19 recordsLinked to original sources
PubMed2000

Heteromorphic antennules protect the olfactory midbrain from atrophy following chronic antennular ablation in freshwater crayfish.

Posthatch larval crayfish (Procambarus clarkii) were unilaterally antennulectomized and maintained in the laboratory for a 6-month period, during which time all regenerating antennular stumps were periodically excised. In another group of animals at a similar developmental stage a heteromorphic antennule was induced on the side of the head ipsilateral to the chronically sectioned normal antennule. After 6 months, all experimental animals were sacrificed and their brains were fixed and sectioned. Computer-aided quantitative measurements were obtained for the volumes of the olfactory lobes on both the experimental and control sides of the brains of both groups of crayfish. In the brains of the crayfish group in which only chronic antennualectomy had been performed, the olfactory lobe ipsilateral to the lesion was reduced in volume by about 80% compared to the olfactory lobe on the control side. In animals in which the normal antennule had been chronically ablated, but which possessed a heteromorphic antennule on the same side, the olfactory lobe on the lesioned side differed in volume from the control side by a mean value of only 28%. We conclude that afferent fibers from a heteromorphic antennule ipsilateral to a chronically lesioned normal antennule can assume some of the central trophic functions of the afferents from the normal antennule; thus, the presence of a heteromorphic antennule offers some measure of protection from the dystrophic effects of chronic ablation of the normal antennule during development and growth in crayfish.

Animals↗
PubMed2000

Far lateral approach for foramen magnum lesions.

Twelve patients with lesions in the anterior or anterolateral regions of foramen magnum were treated through the far lateral approach. The patients presented with neck pain, dysesthesia, quadriparesis, numbness, respiratory distress, and spastic contractures. Most lesions were meningiomas and neurofibromas, with one patient each with a posterior inferior cerebellar artery aneurysm, neurenteric cyst, and chordoma. All mass lesions were excised totally and the aneurysm was clipped. Three patients had severe respiratory problems preoperatively and two of them died. The other patients made a satisfactory neurological recovery. It was not found necessary to resect the condyle or mobilize the vertebral artery in any of the patients.

Adolescent↗
PubMed2000

Effect of pipecuronium and pancuronium on intracranial pressure and cardiovascular parameters in patients with supratentorial tumours.

A prospective, randomised, single blind study was conducted to evaluate and compare the intracranial pressure (ICP) and cardiovascular effects of pipecuronium (PPC) and pancuronium (PNC) in 20 patients undergoing supratentorial surgery. Patients were randomly divided into two groups. Patients in Group I (n = 10) received pancuronium (0.1 mg kg(-1)) and in Group II (n = 10) pipecuronium (0.07 mg kg(-1)) for intubation. Intracranial pressure (ICP), heart rate (HR), systolic, diastolic and mean arterial pressures (SAP, DAP, MAP), central venous pressure (CVP), nasopharyngeal temperature and arterial blood gases (ABG) were monitored at the following time periods: before induction (0 minutes); 3 minutes after thiopentone and muscle relaxant; immediately after intubation; and 4, 6, 8, 10, 20 and 30 minutes following intubation. The rise in intracranial pressure at intubation was significantly greater in group I (21.10+/-3.97 torr, 122.59%) when compared to group II patients (1.80+/-0.70 torr, 10.04%) (p<0.0 1). Cardiovascular parameters also showed a significantly greater degree of rise in group I when compared to group II patients. Heart rate increased by 29+/-6.32 beats min(-1) (33.52%) and systolic arterial pressure by 11.60+/-7.37 torr (9.47%) in group I. These parameters did not change significantly in group II. No significant alterations were observed in the other measured parameters in either of the two groups.

Adolescent↗
PubMed1999

Tethered cord syndrome in adults.

BACKGROUND: The tethered cord syndrome (TCS) is usually diagnosed in childhood and its symptomatic onset in adult life is not common. In the present study, we analyzed the data of patients who presented with TCS in adulthood with the aim of studying the clinical spectrum and management strategies. CLINICAL MATERIAL: Over a 5-year period, 18 adult patients (more than 18 years of age) with TCS were investigated with MRI and were operated on. Patients with adult TCS could be divided into two groups. Group 1 included patients who were asymptomatic in childhood and presented for the first time in adult life (10 patients). The second group was comprised of patients with preexisting static skeletal/neurological deformities who presented in adult life with new or progressive symptoms (eight patients). Eleven patients had cutaneous stigmata, 15 had motor or sensory deficit, nine had back/leg pain, eight had leg atrophy, and six had sphincter disturbances. The most frequent MRI finding was a low lying cord with an intradural and/or extradural lipoma. The cord was detethered surgically and the tethering lesion excised. Pain was usually relieved after surgery (8 out of 9), but only a few patients (2 out of 6) had improvement of sphincter dysfunction. CONCLUSIONS: The late presentation of TCS is possibly related to the degree of tethering and the cumulative effect of repeated microtrauma during flexion and extension. Adult patients with persistent back/leg pain and/or neurological or skeletal deformities should be investigated with MRI to establish an early diagnosis. Surgery should be performed in all adult patients with TCS, once the diagnosis is established.

Adult↗
PubMed1999

Spinal cord injury without radiographic abnormality in adults.

Spinal cord injury without fractures or bony malalignment on either plain radiographs or computed tomography (SCIWORA) is most commonly found in the paediatric age group. In recent years, magnetic resonance imaging (MRI) has been used to evaluate these patients. The present communication describes SCIWORA in 15 adult patients investigated by MRI. Of the 151 patients with spinal cord injury in 1 year, 15 adult patients had cervical SCIWORA. All patients were evaluated by MRI. The age ranged from 20 - 60 years. Eleven patients had partial cord injury, two had a complete cord syndrome while two had a central cord syndrome. MRI demonstrated an intervertebral disc prolapse in six patients, intramedullary haematoma/contusion in four and cord oedema in four patients. One patient had multiple disc prolapses and associated intramedullary haematoma. Patients with disc prolapse were operated upon and all showed neurological improvement. The rest of the patients were managed conservatively. There was mild improvement in patients with intramedullary haematomas while those with cord oedema alone showed moderate recovery. The pathogenesis of adult SCIWORA is possibly different from that in paediatric age group. Most of the patients with SCIWORA show some abnormality on MR imaging. MRI should therefore be done in all patients with spinal cord injury for diagnostic and prognostic purposes.

Adult↗
PubMed1999

Midline and far lateral approaches to foramen magnum lesions.

Twenty patients with foramen magnum lesions were operated upon in the last 5 years at Postgraduate Institute of Medical Education and Research, Chandigarh. The common presenting features were quadriparesis, quadriplegia, diminished sensations, neck pain and respiratory insufficiency. The lesions encountered were meningiomas, neurofibromas, posterior inferior cerebellar artery aneurysms, neurenteric cyst and chordoma. Patients with posterior or posterolaterally placed lesions were operated by the midline posterior approach while those with anterior or anterolateral lesions were managed by the far lateral approach. All mass lesions were excised completely and the aneurysms were clipped. Seventeen patients made good neurological recovery while three died. The latter three patients presented very late. The merits of various surgical approaches to the foramen magnum are discussed.

Adolescent↗
PubMed1997

Growing skull fractures: a clinical study of 41 patients.

Growing skull fractures are rare complications of head injury, occurring almost exclusively in infants and children under the age of three. A retrospective review at our Institute yielded 41 patients with this entity over a period of 20 years (1975-1995). The age at presentation ranged from less than 1 year to 62 years, with 33 (80.5%) patients being less than 5 years of age. The cause of injury was either a fall from a height (93%) or a road traffic accident. The most common location of a growing skull fracture was either parietal or frontoparietal (56%). One patient had a posterior fossa growing skull fracture. CT scan was performed in 19 patients which demonstrated an underlying porencephalic cyst, hydrocephalus or a cyst communicating with the ventricle. In 5 children, a ventriculo-peritoneal shunt alone was performed. Twenty four patients underwent a duro- and cranioplasty while a duroplasty alone was performed in 8 patients. The material used for cranioplasty included acrylic, wire mesh, steel plates or autologous bone. Three patients died, one due to an anaesthetic complication and two as a result of postoperative meningitis. Post-operative CSF leaks occurred in 3 patients, which were managed by a lumbar drain. Six patients had local wound infection.

Adolescent↗
PubMed1997

Intracranial fungal granuloma.

BACKGROUND: Intracranial fungal granulomas are uncommon and their pathogenesis, clinical picture, and effectiveness of therapy remains unclear. METHODS: Thirty-two cases were studied retrospectively in two groups: (1) Rhinocerebral group (22 cases) had a chronic paranasal sinus (PNS) disease with secondary involvement of skull base, cranial nerves, and/or brain. The granulomas were adherent to dura, firm, avascular, and tough, requiring a knife to cut. (2) Primary intracranial group (10 cases) had no detectable PNS lesion at initial presentation. The granulomas were soft, suckable, and contained pus or necrotic material. RESULTS: Postoperative and overall mortality were 37.5% and 50%, respectively. Meningoencephalitis was the most common cause of death. Altered sensorium, pus in the granuloma, and/or severe brain edema were poor prognostic factors. All survivors except four have symptomatic residual or recurrent lesions. CONCLUSION: Early diagnosis with MRI or stereotactic biopsy, radical surgery, and high dose and chronic suppressive chemotherapy may improve overall results in these cases.

Adolescent↗
PubMed1995

Multiple pyogenic brain abscesses.

Thirty eight patients with multiple pyogenic brain abscesses constituted 11% of all the brain abscesses treated during a 12 year period. Sixty per cent (23) of the patients were in the first two decades of life, including 9 (24%) infants. The clinical presentation was similar to brain abscess in general. 21 patients had altered "sensorium" at the time of admission. Otogenic brain abscesses were the commonest (26%), followed by those associated with congenital cyanotic heart disease (18%). The abscesses were invariably large in size. The pus was sterile on culture in 11 (29%) patients, while Staphylococcus aureus was the commonest organism grown in 9 (24%) patients. Aspiration of the pus was required as a life saving measure, to control raised intracranial pressure, in 29 (76%) patients. Twelve (32%) of these patients underwent secondary excision of the abscess capsule. The overall mortality was 32% with failure to control intracranial and systemic infection as the major causes of mortality. Level of consciousness at the time of admission was the most significant factor affecting the outcome. Surgery has a definite therapeutic and life saving role in the management of multiple pyogenic brain abscesses. A systematic treatment plan for multiple abscesses is proposed.

Adolescent↗
PubMed1994

Supratentorial tumours in infants.

Three hundred and ninety-six paediatric (below 15 years of age) patients with brain tumours were treated at our institute in the last 4 years. Eighty-two of the tumours were located supratentorially. These 82 patients included 14 infants (below 1 year of age), who made up 3.5% of all paediatric patients with brain tumours and 17% and those with brain tumours in a supratentorial location. There was a male preponderance, and two-thirds of the 14 patients were within their first 6 months of life. Increasing head size, vomiting and failure to thrive were the common presenting features. One infant presented with asymmetric skull growth. The tumours tended to be large, occupying almost the entire affected cerebral hemisphere; histological types included astrocytomas, malignant astrocytomas, glioblastoma multiforme, primitive neuroectodermal tumours, malignant choroid plexus papillomas and malignant teratomas. Two children had congenital tumours and another two tumours, in children with associated lobar agenesis, were thought to be congenital in origin. Associated hydrocephalus was present in seven patients, but precraniotomy shunt was required in only two patients. The perioperative (within 1 month) mortality was 57%. Only 30% of the patients survived for more than 1 year after surgery and chemotherapy. The longest survival was 20 months. Delay in diagnosis, poor general condition prior to surgery, and the high vascularity and malignant nature of these tumours accounted for the poor results.

Astrocytoma↗
PubMed1994

Brain metastasis from urachal carcinoma: case report.

A rare case of metastasis to the brain from an urachal carcinoma is reported. Metastasis in the brain developed 7 months after partial cystectomy and radiation therapy. Cranial computed tomography showed a ring-enhancing mass lesion that was excised. A month later, the patient died of distant metastasis.

Adenocarcinoma↗
PubMed1993

Posterior fossa extradural haematoma--experience of nineteen cases.

Twenty-four cases of posterior fossa extradural haematoma constituted 4.16% of all extradural haematomas (576) and 1.12% of all craniocerebral trauma requiring surgery (2150). Five cases were excluded from this study. Of the remaining nineteen cases (the study group), lucid interval was present in eight (42.10%) cases. In half of the cases, the clinical course was acute. Neck stiffness and drowsiness were the commonest clinical signs. Occipital bone fracture was present in 57.89% cases. CT scan was the most valuable investigation in the diagnosis and detection of the associated intracranial injury in 18 cases. Associated intracranial injury was present in seven (36.84%) of these cases. Two (11.1%) of these patients died despite emergency surgery. The Glasgow Coma Scale prior to operation and the presence of associated supratentorial injuries were important prognostic factors. It is concluded that posterior fossa extradural haematoma should be suspected in the presence of a fall on the back of the head, drowsiness, neck stiffness or an occipital bone fracture.

Adolescent↗
PubMed1992

Intramedullary spinal cord abscess: a case report.

An 11-year-old boy presented with pain in the back, urinary retention, paraplegia and loss of sensations below L1. Investigations revealed an intramedullary lesion. An intramedullary spinal cord abscess was found at surgery. The pus was evacuated and abscess was excised. Minimal recovery was seen following surgery. Early intervention and a high index of suspicion is required in such cases.

Abscess↗
PubMed1992

Spontaneous spinal extradural hematoma in children. Report of three cases and a review of the literature.

Three young children who presented with acute backache and rapidly progressive neurological deterioration were investigated and found to have spontaneous spinal extradural hematoma (SSEDH). They were operated on soon after the diagnosis had been confirmed. The present report highlights the fact that in children progressive weakness of nontraumatic origin should be investigated thoroughly and as early as possible. Patients with SSEDH should be operated on immediately, as this is a curable condition. The pertinent literature has been reviewed.

Child↗
PubMed1992

Air in epidural haematomas.

Air in epidural haematoma is an uncommon finding. It is usually seen if epidural haematoma is associated with fracture involving one of the air sinuses, but can be seen at times in the absence of any demonstrable fracture on the CT scan. Seven such cases are described in the present communication and the significance of this finding discussed.

Female↗
PubMed1990

Meningeal melanocytoma: report of two cases.

Two cases meningeal melanocytoma, one each at cranial and spinal location, are described. Neurological deficits in both cases improved following surgery. Pathological features of this rare tumour are discussed.

Adult↗