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Biomedical subjects

N Muthukumar

Publications and source records attributed to N Muthukumar.

At least 19 recordsLinked to original sources
PubMed2006

Water-soluble inhibitor on microbiologically influenced corrosion in diesel pipeline.

The effect of water-soluble corrosion inhibitor on the growth of bacteria and its corrosion inhibition efficiency were investigated. Corrosion inhibition efficiency was studied by rotating cage test and flow loop techniques. The nature of biodegradation of corrosion inhibitor was also analyzed by using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR) and Gas chromatography and mass spectrometer (GC-MS). The bacterial isolates (Serratia marcescens ACE2, Bacillus cereus ACE4) have the capacity to degrade the aromatic and aliphatic hydrocarbon present in the corrosion inhibitor. The degraded products of corrosion inhibitor and bacterial activity determine the electrochemical behaviour of API 5LX steel. The influence of bacterial activity on degradation of corrosion inhibitor and its influence on corrosion of API 5LX have been evaluated by employing weight loss techniques and electrochemical studies. The main finding of this paper is that the water-soluble corrosion inhibitor is consumed by the microbial action, which contributes to the decrease in inhibitor efficiency. The present study also emphasis the importance of evaluation of water-soluble corrosion inhibitor in stagnant model (flow loop test) and discusses the demerits of the water-soluble corrosion inhibitors in petroleum product pipeline.

Anti-Bacterial Agents↗
PubMed2006

Thoracic myelocystoceles--two variants.

Myelocystoceles are rare lesions. Rarer still are thoracic myelocystoceles. Two patients with thoracic myelocystoceles are being reported. The first patient presented with swelling in the thoracic region with paraplegia and incontinence. MR with MR myelography revealed the malformation to be a thoracic myelocystocele. The second patient presented with a midline cutaneous mass lesion without neurological deficit. MRI revealed a Type I split cord malformation, a CSF containing sac in the thoracic region that communicated through a stalk-like structure to the hydromyelic hemicord. Surgery in both these patients did not produce any change in the neurological status. The importance of recognizing thoracic myelocystoceles, their clinical presentation, embryology, value of MR myelography in the diagnosis and role of surgery are discussed. The differences between terminal myelocystoceles and thoracic myelocystoceles are also highlighted.

Arnold-Chiari Malformation↗
PubMed2005

A morphometric analysis of the foramen magnum region as it relates to the transcondylar approach.

BACKGROUND: The transcondylar approach is being increasingly used to access lesions ventral to the brainstem and cervicomedullary junction. Understanding the bony anatomy of this region is important for this approach. The purpose of this study was to conduct a morphometric analysis of the hypoglossal canal (HC), occipital condyle (OC) and the foramen magnum (FM) as it pertains to the transcondylar approach. METHODS: 50 dry skulls provided 100 hypoglossal canals, 100 occipital condyles and 50 foramina magna. Twenty one parameters were analyzed. They were: length of the HC, diameter of the intra- and extracranial ends of the HC, angle of the HC to the sagittal plane, distance of the HC from the posterior, anterior and inferior margins of the OC, antero-posterior and transverse diameter of the OC, presence of condylar foramen, distance of HC from the jugular foramen intra- and extracranially, distance of HC from basion, opisthion, carotid canal and jugular tubercle. The anteroposterior and transverse diameters of the FM were measured and a FM index was calculated by dividing the AP diameter of the FM by the transverse diameter. The angle of the long axis of the occipital condyles to the sagittal plane was measured. Protrusion of the occipital condyle into the foramen magnum was noted. Where applicable, the measurements were made separately for the right and left side. FINDINGS: The average length of the hypoglossal canal in this study was 12.6 mms. The hypoglossal canal makes an angle of 49 degrees to the sagittal plane. In 30% of the dry skulls studied, the HC was divided into two by a bony septum. The distance of the intracranial end of the HC from the posterior margin of the OC was 12.2 mms. The average anteroposterior length of the occipital condyle was 23.6 mms and the transverse diameter was 14.72 mms. The occipital condyle made an angle of 60 degrees to the sagittal plane. In 20% of the skulls studied the occipital condyle protruded into the foramen magnum. The condylar foramen was absent on the right side in 4 skulls and on the left side in 16 skulls. The average anteroposterior length of the foramen magnum was 33.3 mms and the width was 27.9 mms. When the foramen magnum index was > 1.2, the foramen was found to be ovoid. Forty six percent of the skulls studied exhibited an ovoid foramen magnum. CONCLUSIONS: The occipital condyle is frequently being drilled to expose lesions ventral to the brainstem. From our study, it is evident that the occipital condyle can be safely drilled for a distance of 12 mms from the posterior margin before encountering the hypoglossal canal. In 20% of the skulls the occipital condyle protrudes significantly into the foramen magnum. Wide and sagittally inclined occipital condyles, medially protruberant occipital condyles along with a foramen magnum index of more than 1.2 will require much more extensive bony resection than otherwise. With the availability of recent imaging techniques, it is possible to anticipate the extent of bony resection required in an individual case by using the above mentioned morphometric features.

Cadaver↗
PubMed2005

Idiopathic hypertrophic cranial pachymeningitis masquerading as Tolosa-Hunt syndrome.

Idiopathic hypertrophic cranial pachymeningitis is a rare condition. A case of idiopathic hypertrophic cranial pachymeningitis presenting as Tolosa-Hunt syndrome is being reported. The importance of neuroimaging in patients with suspected Tolosa-Hunt syndrome is discussed. Tolosa-Hunt syndrome might represent a focal manifestation of Idiopathic hypertrophic cranial pachymeningitis. Future studies are necessary to further clarify the relationship between these two conditions.

Anti-Inflammatory Agents↗
PubMed2004

Mild head injury: revisited.

OBJECTIVE: 1. To define the incidence of positive CT scans in patients with different grades of mild head injury (MHI), 2. To identify clinical predictors of positive CT scans, 3. To evaluate the usefulness of plain radiographs in the triage of patients with MHI, 4. To evaluate frequency and nature of surgical intervention in MHI, 5. To evaluate the risk of deterioration in MHI, and 6. To find out whether patients with normal neurological examination and normal CT can be safely discharged. METHODS: In a prospective study conducted over a period of four months in our center, all patients with mild head injury (defined as Glasgow Coma Scores (GCS) 13-15) were admitted to the head injury unit. Patients underwent standard clinical examination, skull radiography and cranial CT. No clinical criteria were used to select patients for CT scanning and all the patients were subjected to CT. Patients with negative findings on CT and a normal neurological examination were discharged after 24 hours of observation. Patients with positive findings on cranial CT were treated either medically or surgically as deemed necessary. Outcome measures included safe discharge, clinical deterioration, need for surgical intervention or death. The following factors were analyzed statistically to find out whether they can be used as predictive factors for positive cranial CT. They were: age, sex, mode of injury, loss of consciousness, post-traumatic seizures, ear/ nose/throat bleeding, vomiting, admission GCS score, scalp injury, polytrauma, focal neurological deficit, fractures visualized on skull radiography. RESULTS: Three hundred and eighty one patients were included in the study. Of these males constituted 63%, females 17% and children 20%. RTA was the most common mode of injury. Seventy five percent of the patients had GCS of 15, 15% had GCS of 14 and 10% had GCS of 13. Thirty eight percent of the patients had positive findings on the CT. Age, mode of injury, loss of consciousness, post-traumatic seizures, ENT bleeding, vomiting, scalp injury and polytrauma were not found to be predictors of positive CT. Admission GCS score, focal neurological deficits, and fractures detected by skull radiography were found to be statistically significant predictors of positive findings on CT. Seven percent of patients required surgical intervention. Six percent of patients showed neurological deterioration and there was one death in this series of MHI patients. Patients with multiple lesions on CT had a higher chance of deterioration than those with a single lesion. No patient who had a GCS of 15 and normal CT developed any complication during the hospital stay or after discharge. CONCLUSIONS: The incidence of positive CT scans in this prospective, consecutive, unselected cohort of MHI patients was 38%. Lower admission GCS scores, focal neurological deficits, and fractures detected by skull x-rays were found to be significant predictors of positive CT. Other clinical parameters were not found to be predictors of positive CT. CT was found to be superior to plain x-rays in detecting skull fractures. Seven percent of this cohort required neurosurgical intervention. Six percent showed neurological deterioration and there was one death in this series. Patients with multiple lesions on CT had a higher chance of deterioration than those with single lesions. The duration of hospital stay was prolonged in patients with positive CT. As no patient with a normal neurological examination and a normal CT deteriorated, we believe these patients can be safely discharged without need for admission and observation.

Adolescent↗
PubMed2004

Cerebral venous sinus thrombosis and thrombophilia presenting as pseudo-tumour syndrome following mild head injury.

Cerebral venous sinus thrombosis (CVT) after mild head injury is infrequent. A 38-year-old patient presented with a Glasgow Coma score (GCS) of 15 after a road traffic accident. CT scan revealed a temporal contusion. He was treated with measures to prevent cerebral oedema and anticonvulsants. Three weeks later he presented with features of pseudo-tumour syndrome. Investigations revealed the presence of cerebral venous sinus thrombosis, protein C deficiency and elevated titres of antiphospholipid antibodies. He was treated with anticoagulants and showed improvement. This case report highlights that multiple "hits" may lead to CVT and hence laboratory screening of patients with CVT is necessary even if the clinical situation seemingly provides sufficient explanation for a thrombotic event. The presence of acquired and inherited causes of thrombophilia need not always lead to symptomatic thrombosis. As illustrated by this case, a second hit, such as trauma, may be the precipitating factor that unmasks the prothrombotic state.

Adult↗
PubMed2004

Patellar fracture following surgery for patellar instability.

We present a case of patellar fracture in a teenager that followed a soft tissue realignment surgery for patellar instability. We propose that this fracture was due to disruption of the blood supply to the patella as a result of the procedure. To our knowledge this complication, which has been documented following Total Knee Arthroplasty, has not been documented in the English literature before.

Adult↗
PubMed2003

Microbiologically influenced corrosion in petroleum product pipelines--a review.

Microbiologically influenced corrosion is responsible for most of the internal corrosion problems in oil transportation pipelines and storage tanks. One problematic area in treating gas lines is the occurrence of the stratification of water in the line. Under these conditions, corrosion inhibitors do not come into contact properly and oil and inhibitors undergo degradation. The role of bacteria on oil degradation, the consequences of oil degradation in fuel systems and its influence on corrosion have been explained in detail. Besides, factors influencing on degradation of oil and corrosion inhibitors have also been discussed. Mechanism of microbiologically influenced corrosion in oil pipeline has been explained. Many of the misapplication of biocides/inhibitors occur mainly because the characteristics of biocides/inhibitors are not considered before use in pipeline industry. List of biocides and monitoring programme have been collected from literature and presented.

Bacteria↗
PubMed2002

Surgical management of cirsoid aneurysms.

BACKGROUND: Cirsoid aneurysms (arteriovenous fistulas) of the scalp are rare lesions. They are infrequently encountered in neurosurgical practice. These lesions are difficult to manage because of their complex vascular anatomy, high shunt flow and cosmetic disfigurement. We report our experience in the surgical management of these lesions. METHODS: We treated 11 patients with cirsoid aneurysms surgically. All except one patient were males who were in the second and third decades of life. History of trauma was present in 6 patients. In one patient, the lesion had been present since birth. Occipital and frontal regions were the sites commonly involved. Superficial temporal, occipital and posterior auricular arteries were the most frequent feeding arteries. The size ranged from 3 cms to 12 cms. Following investigations were done: CT, MRI, MRA, angiography and Doppler studies. FINDINGS: Excision of the lesion was done in 8 patients and en bloc resection of the lesion with the scalp with reconstruction was done in the remaining three. One among the three patients who underwent en bloc resection had undergone prior surgery. None of the patients underwent preoperative endovascular treatment. One patient had undergone intralesional injection of sclerosing agents twice. Superficial scalp necrosis occurred in two patients but was treated successfully. All the patients except one had good cosmetic results and there was no recurrence during an average follow up of 18 months. INTERPRETATION: Surgical excision with good cosmetic results is feasible in patients with cirsoid aneurysms.

Adolescent↗
PubMed2001

Bilateral internuclear ophthalmoplegia following mild head injury.

A 7-year-old child presented with bilateral internuclear ophthalmoplegia (INO) following a trivial head injury. CT was normal. MRI revealed a pontine lesion. Two months after the injury the patient was neurologically normal. INO following head injury is rare. Rarer still is INO following mild head injury. To date, only four cases of INO had been reported following mild head injury; the present case is the fifth and the first in which the lesion was documented using MRI. The relevant literature is reviewed.

Child↗
PubMed2001

Segmental neurofibromatosis-induced spinal cord compression. Case report.

Spinal segmental neurofibromatosis (NF) is a rare entity. To date, patients in reported cases of segmental NF (or NF5) have harbored neurofibromas involving the peripheral nerves only. The author reports a rare case of segmental NF that caused spinal cord compression in a 40-year-old woman who presented with a 6-month history of intercostal neuralgia. Examination revealed mild lower-extremity weakness and dysesthesia in the right-sided T-9 dermatome. Magnetic resonance imaging revealed three neurofibromas involving the T-9 region, which were excised, and the patient's neuralgic pain was resolved postoperatively. Traditionally, it has been believed that segmental NF involved only the peripheral nerves. The present case illustrates that although rare, spinal cord compression can also occur in patients with segmental NF.

Adult↗
PubMed2000

Tethered cord syndrome in children with anorectal malformations.

OBJECT: Anorectal malformations are known to be associated with neurological deficits, which may contribute to the disability suffered by patients with these malformations. This study was undertaken to determine the incidence and pattern of sacral abnormalities in children with anorectal malformations, the incidence and nature of the neurological deficits, and the incidence and nature of operable intraspinal abnormalities in patients with this condition. METHODS: Neurological evaluation was performed in 81 children with anorectal malformations. Plain x-ray films were obtained to identify the presence of sacral abnormalities. The patients with neurological deficits were evaluated for the presence of operable intraspinal anomalies, and when such anomalies were identified, correction of the same was undertaken. In 21% of these children radiographic evidence of sacral abnormalities was shown. Fifteen percent of patients harbored neurological deficits, and 10% harbored operable intraspinal anomalies. In addition, one patient had split notochord syndrome. Patients with operable intraspinal anomalies underwent surgical correction, with resultant neurological improvement. CONCLUSIONS: Bone abnormalities of the sacrum, neurological deficits, and operable intraspinal lesions are not uncommon in children with anorectal malformations. Because the neurological deficits can contribute to the disability suffered by these individuals, we recommend routine screening of patients with anorectal malformations and neurological deficits and/or sacral abnormalities for the early identification and treatment of potentially correctable intraspinal lesions.

Anal Canal↗
PubMed2000

Calcium pyrophosphate dihydrate deposition disease causing thoracic cord compression: case report.

OBJECTIVE AND IMPORTANCE: Calcium pyrophosphate dihydrate (CPPD) deposition disease is being increasingly recognized. Spinal involvement in CPPD deposition disease is rare. When involved, the cervical and lumbar regions are commonly affected. We report a rare case of CPPD deposition disease that caused thoracic cord compression. CLINICAL PRESENTATION: A 45-year-old woman presented with clinical features suggestive of thoracic cord compression. Radiographic findings were consistent with calcification of the ligamenta flava in the lower thoracic levels causing cord compression. Calcification of the ligamentum flavum is commonly attributed to CPPD deposition disease. Evaluation for conditions that might be associated with CPPD deposition disease proved to be negative. INTERVENTION: Laminectomy with removal of the calcified ligamenta flava was performed. Histopathological examination of the excised ligaments revealed evidence of CPPD crystals. Postoperatively, the patient's spasticity decreased and sensations improved, with no significant improvement in motor power. CONCLUSION: Calcification of the ligamenta flava due to CPPD deposition disease is a rare cause of thoracic cord compression. CPPD deposition disease should be entertained in the differential diagnosis of thoracic cord compression.

Chondrocalcinosis↗
PubMed1999

Stereotactic radiosurgery for anterior foramen magnum meningiomas.

BACKGROUND: Total microsurgical resection is the procedure of choice for growing and symptomatic foramen magnum meningiomas. We hypothesized that for patients with advanced age, complicating medical conditions, or residual or recurrent meningiomas at the foramen magnum, stereotactic radiosurgery would be a useful adjunctive (n = 2) or alternative (n = 3) treatment. METHODS: We report our experience in five elderly patients (73-84 years) who underwent gamma knife radiosurgery. The median tumor volume was 10.5 ml and the tumor margin dose varied from 10 to 16 Gy. Because of the irregular tumor volumes along the inferior clivus, multiple isocenters of irradiation were required (range, 2-8; mean 4.4). RESULTS: During the follow-up interval of 1-5 years (median, 3 years), one patient died of an intercurrent illness, and all remaining patients were stable without any further deterioration in their clinical condition. Follow-up imaging studies revealed a reduction in tumor volume in one patient and no further growth in the remaining four. CONCLUSION: We believe that stereotactic radiosurgery provides safe and effective management for patients who are poor candidates for resection of their foramen magnum meningiomas.

Aged↗
PubMed1999

Stereotactic radiosurgery for jugular foramen schwannomas.

BACKGROUND: Jugular foramen schwannomas pose difficult management problems because of the surgical risk of lower cranial neuropathy. The indications and results of stereotactic radiosurgery are not well documented. METHODS: We reviewed our 10-year experience in the management of 17 patients who had jugular foramen schwannomas managed with the gamma knife. Thirteen patients previously had undergone surgery (range, 1-6 resections). Four patients had multiple cranial nerve deficits before microsurgical resection; 12 developed multiple lower cranial nerve palsies after resection. Four patients underwent radiosurgery based on imaging criteria alone. Conformal dose planning (tumor margin dose of 12-18 Gy) successfully encompassed the irregular tumor volumes in all patients. RESULTS: Follow-up varied from 6 to 74 months. Tumor size decreased in eight patients, remained stable in eight, and increased in one patient during the average follow-up interval of 3.5 years. Six patients improved and 10 others retained their preradiosurgery clinical status. One patient had an increase in tumor size and clinical deterioration 6 months after radiosurgery and underwent microsurgical resection. No patient developed new cranial nerve or other neurological deficits after radiosurgery. CONCLUSIONS: We believe that gamma knife radiosurgery is an effective alternative to microsurgical resection for patients who have small tumors and intact lower cranial nerve function. It is also effective for patients who have residual or recurrent tumors after microsurgical resection.

Adult↗