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Biomedical subjects

A K Mahapatra

Publications and source records attributed to A K Mahapatra.

At least 19 recordsLinked to original sources
PubMed1996

Intracranial intraparenchymal schwannomas: a series of eight cases.

Intraparenchymal schwannomas of the CNS are extremely rare. Between 1979 and 1993 400 cases of intracranial schwannomas were operated on and among them were eight patients with intraparenchymal schwannomas comprising 2% of intracranial benign nerve sheath tumours. Four of them were located in the cerebral hemispheres and two each in the brain stem and in the cerebellum. In two cases, there was associated neurofibromatosis (NF-1 and NF-2, one case each). The age ranged from 6 months to 45 years with a male/female ratio of 3:1 and, surprisingly, six of them were in the left cerebral or cerebellar hemisphere.

Adolescent↗
PubMed1995

Serial transcranial Doppler study in meningitis.

Serial transcranial doppler studies were carried out in 12 patients, who developed meningitis during their hospital stay. Blood flow velocities in large basal vessels of the anterior circle of Willis were correlated with CSF pleocytosis and CSF sugar values. Mean blood flow velocities were found to be directly proportional to the CSF white blood cell (WBC) count and were inversely proportional to the CSF sugar values. Blood flow velocities were higher when CSF WBC count was raised. With only one exception these velocities decreased progressively with a fall in the CSF WBC count. At the time of meningitis there occurred a reduction in CSF sugar values and the blood flow velocities were significantly higher. With increase in CSF sugar values there occurred a gradual fall in the blood flow velocities.

Adolescent↗
PubMed1995

The blink reflex before and after percutaneous glycerol rhizotomy in patients with trigeminal neuralgia--a prospective study of 28 patients.

The blink reflex was prospectively studied in 28 patients with trigeminal neuralgia, prior-to and following percutaneous glycerol rhizotomy to the Gasserian ganglion. Fifteen patients (54%) had varying degrees of sensory loss in the trigeminal nerve distribution already before glycerol injection. Three more patients developed sensory loss following glycerol injection. Thus following glycerol injection 18 patients had graded sensory loss. Pre-injection the blink reflex showed abnormal R1 wave in 57% patients, while direct and consensual R2 waves were abnormal in 43% and 48%, respectively. Post-injection R1 wave was abnormal in 64% patients. Direct R2 waves were abnormal in 33% patients. Thus clinical findings of sensory loss correlated well with pre-and post-injection blink reflex abnormality. Postoperatively R1 and ipsilateral R2 latencies from the side of the injection deteriorated and consensual R2 latency improved, thus, signifying better function on the contralateral side following relief of pain by glycerol rhizotomy.

Adult↗
PubMed1994

Anterior encephaloceles: a report of 30 cases.

Thirty cases of anterior encephalocele treated in our centre over an 18-year period (from 1973 to 1990) are presented. At the time of surgery over 60% of the patients were under the age of 2 years, and 40% were aged under 1 year. Only one child was over 10 years of age. Twenty-six patients had the fronto-ethmoidal type of defect, while two each had frontonasal- and naso-orbital-type lesions. Twenty-five children had varying degrees of hypertelorism. Four had an enlarged head and four microcephaly. In 26 patients one-stage repair of the encephalocele and reconstruction of the orbits was undertaken. A ventriculoperitoneal shunt was performed prior to definitive surgery in three patients with gross hydrocephalus. There was no postoperative mortality. Six patients had postoperative CSF rhinorrhoea, three of them requiring a lumboperitoneal shunt. This study highlights the role of one-stage repair of this defect.

Age Factors↗
PubMed1994

Trans-ethmoidal optic nerve decompression.

Blunt head injury frequently results in visual impairment, the optimal treatment of which is still debated. Over a 5-year-period (1987-1991) 111 patients with indirect optic nerve injury resulting from closed head trauma have been treated. In each case loss of vision was the only neurological deficit. In group A, 66 patients were initially treated with large doses of prednisolone (80 mg/day) for 3 weeks. Twenty-seven patients improved on steroids alone. In the remaining 39 patients in whom either unsatisfactory or no improvement occurred a transethmoidal optic nerve decompression was performed. Twenty-two patients in the latter group improved, thus yielding an overall improvement rate of 74.2% in group A. Group B (control), in which 45 patients were treated with prednisolone only (80 mg/day for 3 weeks), had an overall improvement rate of 51% (23 patients). The study reveals that while nearly half of such patients can improve on steroids alone, optic nerve decompression significantly improves recovery rates in patients where conservative treatment is unsatisfactory (P < 0.05). Total loss of vision not responding to steroids, absence of waveform on visual evoked response, and presence of an optic canal fracture indicate a poor prognosis.

Adult↗
PubMed1994

Pre and postoperative median nerve conduction in patients with pituitary tumour.

A study of median nerve sensory conduction at the wrist was performed in 34 patients with pituitary adenomas prior to and following surgery. In 31 patients this was done bilaterally. They included 11 patients with acromegalic features, 3 of whom had features of carpal tunnel syndrome. Six out of 11 (55%) acromegalics had abnormal latencies and conduction velocities pre-operatively. Among the remaining patients only 3 had conduction delay pre-operatively. Postoperative improvement in conduction velocity and latency was recorded in 24 patients although significant improvement was observed in only 13 patients. All 3 patients with carpal tunnel syndrome had significant improvement in conduction velocities and latencies following the surgery. There was no definite relationship between conduction velocity and the pre-operative hormonal profile.

Acromegaly↗
PubMed1994

Primary cerebellopontine angle choroid plexus papilloma: a case report and review of literature.

A case of primary choroid plexus papilloma of the cerebellopontine (CP) angle is described in a 28 years old man. He presented with hearing loss, right facial palsy and spastic quadriparesis (4/5). He also had markedly increased intracranial pressure. CT scan revealed a large high attenuating lesion in right CP angle with gross hydrocephalus. The patient was operated with the clinical and radiological diagnosis of right sided acoustic tumor with brainstem compression. Radical tumour excision was performed, seven days following VP shunt. Patient had immediate postoperative deterioration followed by a steady recovery. The possibility of a secretory choroid plexus papilloma is discussed.

Adult↗
PubMed1994

Solitary intracranial plasmacytoma of the skull base.

Two cases of extradural solitary plasmacytoma (SIP) with infiltration of the dura, destruction of the skull base, multiple cranial nerve palsies and proptosis are presented. The cases were treated aggressively with surgery and radiotherapy and showed no signs of progressing to multiple myeloma after 15 months and four and a half years respectively.

Adult↗
PubMed1993

Operations on gliomas involving speech centres.

One hundred patients with gliomas of the dominant hemisphere, who survived for more than one year after operation, have been analysed. In all of them radical tumour removal had been attempted. Already preoperatively 58 of them had signs of speech deficit. Postoperatively 65% improved and only 15% deteriorated with regard to their speech function. Therefore it seems not to be justified to deny operative tumour removal to patients with gliomas located within or near the speech areas.

Adult↗
PubMed1993

Traumatic optic neuropathy in children: a prospective study.

Fifty children with indirect optic nerve injury were prospectively studied over an 8-year period. They constituted 20% of all patients with optic nerve injury managed on a slightly different protocol. Half of these children were injured due to fall from a height, followed by road traffic accidents in 40% of the cases. Forty-three children had unilateral and 7 children had bilateral visual impairment. Five children had definite history of delayed-onset visual involvement, which ranged from 12 to 72 h following injury. Fifty percent of these children had fractured skulls and 14% had optic canal fracture. Visual evoked potentials were performed in 43 patients of which wave formation was normal in 7 and abnormal in 14 patients. The remaining 22 patients had no wave formation. All the patients were managed conservatively and received corticosteroids for a period of 3 weeks. In 7 children an optic nerve decompression was performed between 4 and 6 weeks following injury. Spontaneous visual improvement was observed in 20 (40%) children. In all the patients onset of visual recovery was noticed within 3 weeks. Of the 7 children who had optic nerve decompression, 4 had minimal spontaneous recovery and their vision remained static. All these 4 children benefited by surgery and the vision improved further following the decompression. Three children had no perception of light prior to surgery and none of these patients showed visual improvement following surgery. The present study brings out the clinical profile of children with optic nerve injury and the indications of surgery in these patients.

Adolescent↗
PubMed1993

Sellar-suprasellar primary malignant lymphoma: case report.

A patient who came with compression of the chiasma and later on had involvement of the cavernous sinus is presented. Radiological examination showed a seller, suprasellar and parasellar tumor. Histopathological examination revealed a primary Non-Hodgkins lymphoma.

Adult↗
PubMed1992

Risk factors in postoperative neurosurgical infection. A prospective study.

Four hundred and seventy patients who had undergone neurosurgical operations were studied prospectively. After defining post-operative infection so that is included all the infective complications irrespective of location occurring after surgery, the overall infection rate was 17%. The infection rate in 413 cases without pre-existing infection was 15%. Wound infection was recorded in 5% and meningitis in 6%. Risk factors which lead to a significant increase in the incidence of postoperative infection were found to be altered sensorium, multiple operations, pre-existing infection, emergency surgery, duration of surgery more than 4 hours, urinary catheterisation, cerebrospinal fluid leak, and ventilatory support.

Administration, Oral↗
PubMed1992

Somatosensory and brainstem auditory evoked potential in congenital craniovertebral anomaly; effect of surgical management.

Clinical features and evoked potential recordings were analysed in 32 patients with congenital atlantoaxial dislocation before and after surgery. Seven patients (group 1) had atlantoaxial dislocation, while 22 patients had associated basilar invagination (group 2). In both groups, pyramidal tract signs, posterior column signs, wasting of the upper limbs, and abnormality of somatosensory evoked potentials (SSEP) were similar. Conversely, lower cranial nerve involvement and abnormal brainstem auditory evoked potentials (BAEP) were significantly more in patients with basilar invagination (p less than 0.05). All seven patients in group 1 and 17 patients in group 2 were operated upon. Clinical and electrophysiological deterioration were significant in patients with basilar invagination (group 2), following posterior fixation compared with group 1. Among the patients in group 2, who clinically deteriorated following posterior fixation, seven had transoral excision of odontoid and six of them improved both clinically and electrophysiologically. Two patients in group 2 had odontoid excision before posterior fixation, and in both the evoked potentials improved postoperatively. In group 1 the patient's BAEP remained unaffected following posterior fixation, however, in group 2, eight patients over 53% showed improvement in brainstem function following posterior fixation. This study shows the value of evoked potentials in congenital atlantoaxial dislocation, and rationalizes the surgical procedure in these patients. In patients with basilar invagination, odontoid excision is the preferred first stage procedure.

Atlanto-Axial Joint↗
PubMed1991

Effect of CSF shunt on brainstem auditory evoked potential in hydrocephalus secondary to brain tumour.

BAEPs were prospectively studied in thirty patients with hydrocephalus prior to and within 48 hours of CSF diversion. They comprised patients with (1) cerebellar tumours (2) brainstem tumours (3) third ventricular tumours. Preshunt BAEPs were abnormal in 80% patients with cerebellar tumour, 70% patients with third ventricular tumour and in all patients with brainstem tumour. Postshunt BAEPs improved in 70% patients with brainstem tumour and in 40% patients with third ventricular tumours. In both the groups I-III and III-V interpeak latency improved. In group 1, (cerebellar tumours) none of the patients showed improvement in the BAEP after shunt. In 7 patients of this group CCT deteriorated after the shunt. The deterioration was at the III-V interlatency in 5 patients. One patient had deteriorated at both I-III and III-V levels and another had prolongation of the I-III interlatency after shunting. In 6 patients the wave V amplitude reduced by more than 50% after shunting.

Adolescent↗
PubMed1991

Visual evoked potentials in optic nerve injury. Does it merit a mention?

The value of Visual Evoked Potentials (VEP) in the management of indirect optic nerve injury was prospectively studied in 128 patients. In fifty patients who were either unconscious, uncooperative or had massive black eye, preventing the assessment of vision, a light Emitting Diode (LED) was used to record visual evoked potentials. The initial VEPs were normal in 17, abnormal in 49 and absent in 62. All 17 patients with normal VEP showed visual recovery. Amongst the 49 patients with abnormal VEP, 43 (88%) showed improvement. In 62 patients, initial VEPs showed no response but, in 12 subsequent VEP recordings wave formation was demonstrated. Thus in 50 patients repeated VEP recordings failed to demonstrate wave formation, and none of them improved. This study, thus brings out the high predictive value of both positive and negative VEPs, and specially the role of LED.

Evoked Potentials, Visual↗
PubMed1991

Fibrosarcoma of the scalp following postoperative radiotherapy for medulloblastoma.

A rare case of fibrosarcoma of the scalp following postoperative radiotherapy for medulloblastoma is reported. A review of similar cases in the literature was undertaken in an attempt to find a correlation between the dose of radiation, the length of the latent period, and the nature of the neoplasm. A significantly shorter latent period was found for sarcomas. No relationship was observed between the radiation dose and the latent period. The present case is unique in that the post-irradiation neoplasm (PIN) occurred in a predominantly extracranial site after treatment for a desmoplastic medullobastoma and had a remarkably short latent period.

Cerebellar Neoplasms↗