Biomedical subjects

D K Chhabra

Publications and source records attributed to D K Chhabra.

At least 19 recordsLinked to original sources

PubMed2005

Intracranial aneurysms in patients 18 years of age or under, are they different from aneurysms in adult population?

BACKGROUND: Intracranial aneurysms are extremely uncommon in the first two decades of life. This study was undertaken to assess the clinicoradiological features and surgical outcome of intracranial aneurysms in patients less than or equal to 18 years of age; and, to highlight the differences between these and intracranial aneurysms seen in adult patients. METHODS AND MATERIAL: Twenty-two patients, 18 years of age or under (male:female ratio=1.75:1; mean age 14.18+/-3.8 years, age range 5 to 18 years) and 451 adult patients aged older than 18 years (male:female ratio=1:1.05; mean age 48.21+/-12.71 years, age range, 19 to 81 years) were treated for intracranial aneurysms at our center between January 1991 and July 2003. The univariate statistical analysis was used to compare differences between the two groups. FINDINGS: The patients under 18 years constituted 4.6% of the total patient population having intracranial aneurysms. The incidence of associated medical diseases was greater in patients under 18 years than in the adults (9% versus 0.26%, p<0.05). The incidence of seizures was more than double in patients under 18 years (36% versus 17%, p<0.05). The incidence of intracerebral haematoma (ICH; 41% versus 22.5%, p>0.05), intraventricular haemorrhage (IVH; 45% versus 34%, p>0.05), and hydrocephalus (36% versus 25%, p>0.05) were higher in patients under 18 years. In adult patients, anterior communicating artery (AcoA) and in children, ICA bifurcation were the most frequent sites of aneurysm formation respectively (p<0.05). The incidence of giant aneurysms was nearly double in children (13.6% versus 6.5%, p>0.05). The incidence of clinical vasospasm was almost the same in both groups. The overall outcome was favourable in 82% of patients under 18 years and 58.8% in adults. The management mortality in patients under 18 years was 9.1%, while in the adult patients, it was 19%. CONCLUSION: In patients under 18 years of age, there was a definite male predominance; a higher incidence of seizures; and, the ICA bifurcation formed the most frequent site of intracranial aneurysms. In adults, AcoA a was the commonest site. Rebleeding and delayed ischaemic deficits were the major causes of morbidity. Favorable outcome after surgery in young patients was better in comparison to their adult counterparts.

Adolescent↗

PubMed2004

C3-4 level cervical spondylotic myelopathy.

Cervical spondylotic myelopathy (CSM) is uncommon at the C3-4 level. Fourteen patients with C3-4 CSM were treated over a period of 3 years. The radiological factors contributing to CSM at the C3-4 level were studied. These factors included the assessment of static and dynamic canal diameters, retrolisthesis, posterior osteophytes and degenerative spinal segmental fusion on plain X-rays; and, the antero-posterior cord compression ratio (APCR) on magnetic resonance imaging (MRI). The clinical status of the patients was assessed by the modified Japanese orthopedic association scale (mJOAS). The mean difference between the static and dynamic canal diameters was statistically significant at C3-4 (p < 0.01). The APCR obtained at different levels showed a significant compression at the C3-4 level in comparison to the lower level. There was a correlation between the APCR and the preop mJOAS, r=0.6 (p< 0.05). The mean mJOAS improved from 9.35 to 14.35 at follo-up. The recovery rate calculated using the modified Hirabayashi rate was 66.9%. Degenerative changes at lower cervical segments predispose to increased mobility and spondylotic changes at the C3-4 level. The patients in this study were young as compared to those reported in the international literature.

Cervical Vertebrae↗

PubMed2003

Chiari I malformation related syringomyelia: radionuclide cisternography as a predictor of outcome.

BACKGROUND: This prospective study, conducted in patients with Chiari I malformation (C I) related syringomyelia who underwent posterior decompression and duroplasty, utilizes radionuclide cisternography in order to study the cerebrospinal fluid (CSF) dynamics at the foramen magnum and to predict the clinical outcome following surgery. METHODS: 17 consecutive patients of C I with syringomyelia (but without hydrocephalus or fixed atlanto-axial dislocation), underwent a detailed neurological examination and were assigned a clinical disability score based on the modified Klekamp and Samii score. A radionuclide cisternography (using Tc99m-DTPA) was performed via the lumbar route and the ascent of the tracer was followed utilizing a gamma camera immediately after injection and then sequentially after 1, 2, 4, 6 and 24 hours. After posterior decompression and duroplasty, the modified Klekamp and Samii score was repeated at follow-up visits (range: 3 months to one year) along with radionuclide cisternography at 3 months, and MR imaging at 6 months. FINDINGS: Three patterns of tracer flow were observed: a). rapid flow (n=7); b). supratentorial subarachnoid delay (n=7); and, c). foramen magnum block (n=3). The patients having foramen magnum block had the poorest clinical scores on admission. At follow up, there was an improvement in the clinical scores so that the mean scores in all three categories reached nearly the same level. Following posterior decompression, the radionuclide cisternography performed in 10 patients showed a rapid flow of the tracer without any obstruction. The syrinx resolved in 4 of the 11 patients in whom an MRI was done. INTERPRETATION: The patients with C I with syringomyelia may often have a free flow of tracer across the FM. Posterior decompression and duroplasty provides maximum clinical relief in patients with a demonstrable foramen magnum block on radionuclide cisternography while those with a normal flow have less relief. The symptomatology related to brain-stem compression immediately responds to the surgical procedure but the syrinx-induced signs and symptoms of spinal cord dysfunction persist.

Adolescent↗

PubMed2002

Congenital reducible atlantoaxial dislocation: classification and surgical considerations.

BACKGROUND: Reducible atlanto-axial dislocation (AAD) may cause severe motor and respiratory compromise due to recurrent spinal cord and/or brain stem impingement. To the best of the authors' knowledge, this is the first study concentrating on the classification, the protocol of the surgical management and the outcome of congenital, reducible AAD. METHODS: 109 patients with congenital, reducible AAD underwent posterior stabilization. Their preoperative disability was graded as: I (n=11, 10.09%) no functional disability (a history of minor trauma led to quadriparesis that subsequently improved); II (n=31, 28.44%) independent for activities of daily living with minor disability; III (n=42, 38.53%) partially dependent on others for their daily needs; and, IV (n=25, 22.93%) totally dependent. They were classified into 4 groups depending upon their association with: a normal odontoid and posterior arch of atlas (n=27); a dysplastic odontoid and normal posterior arch (n=25); an assimilated posterior arch (n=49); and, Arnold Chiari malformation type I (n=8). Nine patients with a dysplastic odontoid had a "hypermobile" AAD with an unrestricted backward and forward movement of the axis relative to the atlas in flexion as well as in extension of the neck, respectively. The surgical procedures included Brooks' (n=12) or modified Brooks' C1-2 fusion (n=39); Goel's C1-2 fusion (3); Ransford's contoured rod fusion (n=7); Jain's occipitocervical fusion (n=47); and, transoral decompression and Jain's occipitocervical fusion (n=1). There were 6 peri-operative mortalities in the series. FINDINGS: At follow-up (ranging from 3 months to 6 years; n=86), 64 patients had shown improvement by one grade or more; 8 patients, who had a history of transient quadriparesis but were without neurological deficits at presentation, remained in grade I; 11 had achieved stabilization of neurological functions; while 3 had deteriorated despite adequate radiological reduction of AAD and fusion of the construct. A follow-up of 6 months or more was available in 79 of these 86 patients, in whom a dynamic intrathecal CT scan showed a good osseous union. INTERPRETATION: The patients with congenital reducible AAD, depending on their surgical management, may be classified into four groups. Some patients with a dysplastic odontoid have a "hypermobile" AAD and require special care during intubation, positioning and stabilization. An assimilated posterior arch is often associated with asymmetrical lateral occipito-C1-C2 joint synostosis rendering transarticular screw placement difficult. The various causes of failure of constructs are discussed.

Adolescent↗

PubMed2002

Embolization of cranial/spinal tumours and vascular malformations with hydrogel microspheres. An experience of 69 cases.

OBJECTIVE: To evaluate polymethyl methacrylate hydrogel microspheres (HMs) as an embolization material in the management of hypervascular craniofacial and spinal lesions. MATERIAL AND METHODS: Sixty-nine patients with vascular lesions of the craniofacial and spinal regions underwent embolization with HM. The pathologies included craniofacial tumours (n=38), cranial arteriovenous malformations (AVMs) (n=7), dural AVM (n=1), cavernous carotid fistula (n=1), spinal tumours (n=7), spinal AVMs (n=6), orbital lesions (n=4) and scalp AVMs (n=5). Surgery was done in 56 patients. The blood loss at surgery, tumour shrinkage, surgical cleavage and ease of removal of tumour was noted from the records. Histopathology was available in 39 patients. A follow-up of 3 months to 6 years was available in 13 patients in whom embolization was the sole treatment. Surgical and histopathological findings were correlated with angio-embolization findings. RESULTS: HMs were easy to inject through the microcatheter with good control. Good devascularization was obtained in 61 patients and partial in 8 patients. Two patients developed complications due to presence of anastomoses between intra- and extracranial circulation and 1 patient due to tumor swelling. Histopathology showed presence of HMs in all the lesions, with minimal inflammatory reaction in 2 patients. Patients with spinal lesions treated with embolization only stabilised in neurologic deficits. CONCLUSION: HMs are highly suitable as embolization agents in the management of craniofacial and spinal hypervascular lesions.

Antimutagenic Agents↗

PubMed2002

Choroid plexus papillomas of the cerebellopontine angle.

The cerebellopontine angle (CPA) is a rare site for the growth of choroid plexus papilloma (CPP). The clinicoradiological diagnosis of this tumor in the CPA is difficult because of the nonspecific clinical presentation and radiological features. Five cases of choriod plexus papilloma (3 males, 2 females) operated upon at this center are reviewed. All the cases were operated upon by retromastoid suboccipital craniectomy. As they all presented with a typical CPA syndrome without any distinctive radiological feature, a clinicoradiological diagnosis of CPP could not be reached in any of these. The diagnosis of CPP could only be suspected at the operation table and established on histopathological examination. Two patients developed recurrences at the primary site following surgery. One patient developed recurrence twice despite gross total excision of tumor in each sitting. Subsequently, this patient remained symptom free for a follow-up period of 1 year. Another patient developed recurrence 2 years following surgery, but he died due to septicemia and aspiration pneumonitis. Therefore definitive surgery could not be performed. Radiotherapy was offered to one of the patients having residual mass post operatively, to render her symptom free for a 4 year follow-up. The remaining two patients have also showed progressive improvement in their symptoms following surgery for 4 years on follow-up. Hydrocephalus was a common feature in all the cases preoperatively, but only one required shunt CSF diversion, because of rapid deterioration in visual equity. In all other cases, hydrocephalus was managed conservatively. Surgery remains the main modality of treatment for CPP, both for primary and recurrent tumors, but radiotherapy may have a role in cases of recurrence, which are quite frequent.

Adult↗

PubMed2001

Dandy-Walker syndrome: different modalities of treatment and outcome in 42 cases.

OBJECTS: Forty-two patients with Dandy-Walker syndrome who were treated with different surgical modalities over a period of 8 years, from 1988 to 1996, at the Sanjay Gandhi Post Graduate Institute of Medical Sciences were reviewed in the present study. METHODS: All the patients presented with hydrocephalus at the time of diagnosis. Association of other CNS anomalies was detected in 9 (22%) patients. Vermian hypoplasia was present in 36 (88%) cases, while cerebellar hypoplasia was documented in 27 (59%) of these patients. The treatment modality for these cases has continued to change in our institution over the years. Initially the ventriculoperitoneal shunt was the treatment of choice and was performed in 28 (66%) patients. Subsequently shunting of the cyst to the peritoneal cavity was performed in 7 (16%) patients. More recently, 3 of our patients were treated by fenestration of the cyst membrane and 4 others (9%), by ventriculocystoperitoneal shunting procedures. In this study the additional insertion of cystoperitoneal shunts was required in 8 (27%) of the 28 patients who had primary ventriculoperitoneal shunt procedures, because of either nonresolution or reappearance of a posterior fossa cyst. Six out of the 7 cases of primary cystoperitoneal shunts required additional ventriculoperitoneal shunt diversion because of persistent ventricular dilatation. In the group of 4 patients with primary ventriculocystoperitoneal shunts, only 1 patient required shunt revision. The patients on whom cyst membrane fenestration was performed required no additional procedures, except for 1 who already had a ventriculoperitoneal shunt in situ. CONCLUSIONS: Therefore, 18 of the total 42 patients could ultimately be made asymptomatic by ventriculocystoperitoneal shunting for one or the other of these reasons.

Cerebellum↗

PubMed2001

Uncommon presentation of medulloblastoma.

INTRODUCTION: Medulloblastoma commonly occurs in children as a midline posterior fossa mass arising from the vermis, which appears as a hyperdense, homogeneously enhancing mass on CT scan and is associated with the clinical profile of posterior fossa syndrome. This unique clinico-radiological pattern is considered 'typical', but then medulloblastomas do not follow the typical clinico-radiological pattern in a significant number of cases. PATIENTS: Out of the 42 cases of medulloblastoma operated on at SGPGIMS from 1988 to 1998, 29 cases were retrospectively and 13 cases were prospectively studied to detect the atypical clinico-radiological features. The typical radiological feature of a hyperdense homogeneously enhancing mass was seen in only 23 of the 42 patients, while 5 patients had hypodense nonenhancing masses, 13 had cystic changes, and 6 patients had calcifications in their tumours. Three patients presented with tumours in a very unusual location, i.e. the cerebellopontine angle cistern. RESULTS: During follow-up, which ranged from a minimum period of 1 year to a maximum of 9 years, patients came back with metastases at very unusual sites. There were 5 cases of metastases in the frontal and subfrontal area (developed between 5 months and 5 years following surgery), and 1 patient developed a cervical intramedullary metastasis. Two patients developed abdominal metastases and ascites 2 years after definitive surgery and ventriculo-peritoneal shunting. Each of these 2 patients, however, had received a full course of craniospinal irradiation following surgery. Thus, we had a number of cases with an unusual clinical, radiological and metastatic pattern.

Cerebellar Neoplasms↗

PubMed2001

Thoracic myelopathy secondary to ossified ligamentum flavum.

BACKGROUND: Focal ossification of the ligamentum flavum (OLF) forms one of the rare causes of thoracic myelopathy. The lower thoracic spine is most frequently affected and the patients present with initial posterior column disturbances followed by progressively increasing spastic paraparesis. The pathogenesis of OLF has not been conclusively established. METHOD: Five patients with thoracic myelopathy due to OLF underwent decompressive laminectomy and excision of the ligamentum flavum. Their MRI delineated a linear or beak like excrescence, uniformly hypo-intense on T1 and T2 weighted images, situated posterior to the thecal sac. A comparison between the preoperative neurological status and the status at follow-up was done using Harsh's myelopathic grading. FINDING: Decompressive laminectomy followed by the drilling of the OLF and its excision, occasionally along with the adherent outer layer of the dura, resulted in significant improvement in motor weakness and tingling sensations. However, at the last available follow-up, none of the patients had retained their ability to run briskly (grade I) and all of them had residual spasticity. INTERPRETATION: OLF may significantly contribute to a spatial reduction of the thoracic spinal canal resulting in paraparesis. The T2 weighted sagittal image of the magnetic resonance imaging (MRI) is the modality of choice for screening of the longitudinal extent of the OLF. A rapid neurological improvement occurs following decompressive laminectomy and excision of the OLF. However, the persistence of residual spasticity at follow-up may be due to irreversible changes within the cord by the significant thecal compression and the delay between the onset of initial symptoms and signs and surgical decompression.

Adult↗

PubMed2001

Prospective evaluation of in vivo proton MR spectroscopy in differentiation of similar appearing intracranial cystic lesions.

Proton MR spectroscopy (PMRS) has been found to be useful in differentiating various cystic intracranial lesions. The purpose of the present study was to prospectively evaluate the spectral pattern of various cystic lesions of brain with similar imaging appearances and to determine the accuracy of this technique in the differential diagnosis of these lesions. Fifty-one patients with intracranial cystic lesions (21 abscesses, 20 gliomas, 3 hydatid cysts, 3 arachnoid cysts, 1 case each of glioependymal cyst, xanthogranuloma, infarction and acoustic neuroma) were evaluated with conventional MR imaging and in vivo PMRS. Ex vivo PMRS of the cystic contents aspirated at surgery in 31 cases was also done to confirm the in-vivo results. Preoperative diagnosis of the lesions was based on the results of in vivo PMRS. In vivo PMRS accurately predicted the pathology in 92% of the cases. We conclude that in-vivo PMRS complements imaging in better characterization of cystic intracranial mass lesions.

Adolescent↗

PubMed2001

Spinal intramedullary ependymal cyst. Report of two cases and review of the literature.

Two pediatric patients (4 and 5 years of age) with spinal intramedullary ependymal cysts located at the cervical and dorsal cord are reported here. One patient was admitted with subtle signs, while the other had disabling spastic quadriparesis. In both patients, MRI depicted a well-demarcated, localized, nonenhancing intramedullary lesion isointense with CSF on T(1)- and T(2)-weighted images. Total excision of the covering membrane of the cyst was not possible in either case. The child with spastic quadriparesis had a remarkable recovery, while the subtle signs of the other patient regained normalcy at the follow-up of 4 and 5 months, respectively.

Child, Preschool↗

PubMed2001

Split cord malformation (scm) in paediatric patients: outcome of 19 cases.

There had been considerable debate regarding the surgical outcome of neuro-orthopaedic syndromes (NOS) and neurological syndromes in cases of split cord malformation (SCM). On retrospective analysis of 19 cases of SCM, thirteen were grouped under (Pang) type I and 6 in type II. Their age ranged from 1 month to 9 years (mean 3.5 years). 14 of these were male children. The NOS without neurological signs was detected in 6 cases where as pure neurological signs without NOS were seen in 8 patients. However, the rest 5 had mixed picture of NOS and neurological dysfunction. Nine of 19 cases presented with cutaneous stigmata, mainly in the form of hairy patch. 18 cases had other associated craniospinal anomalies i.e. hydrocephalus, meningomyelocoele, syrinx, dermoid, teratoma etc. Detethering of cord was done in all cases by removal of fibrous/bony septum. Associated anomalies were also treated accordingly. Follow up of these cases ranged from 6 months to 6 years. Six cases of NOS group neither showed deterioration nor improvement, and remained static on follow up. However, four of 8 children with neurological signs showed improvement in their motor weakness, and 1 in saddle hypoaesthesia as well as bladder/bowel function. In 5 cases of mixed group, two had improvement in their weakness and one in hypoaesthesia, but no change was noticed in NOS of this group as well. Hence surgery seemed to be effective, particularly in patients with neurological dysfunction.

Child↗

PubMed2001

Extended frontobasal approach to the skull base.

The extended frontobasal approach provides an adequate midline exposure from the anterior cranial fossa to the sphenoclival region. Between November 1991 and August 1999, 13 patients with extensive anterior and anterolateral skull base tumours extending to supra and parasellar regions, cavernous sinus and sphenoclival regions were operated upon using this approach alone (7 patients) or in combination with subtemporal -infratemporal (4 patients) or transfacial (2 patients) approaches. Gross total excision was performed in 8 patients while in 4 patients with malignant tumours and in a patient with extensive skull base fungal granuloma, only partial excision was possible. Basal repair was performed using pedicled pericranium, temporalis muscle or fascia lata. The complications included increase in the cranial nerve paresis, endophthalmitis, facial oedema, CSF leak, frontal haematoma and internal carotid artery injury. This study reviews the operative technique, the indications and the complications of extended frontobasal approach.

Adult↗

PubMed2001

Anterior retropharyngeal approach to the cervical spine.

The anterior retropharyngeal approach (ARPA) accesses anteriorly situated lesions from the clivus to C3, in patients with a short neck, Klippel Feil anomaly or those in whom the C2-3 and C3-4 disc spaces are situated higher in relation to the hyoid bone and the angle of mandible where it is difficult to approach this region using the conventional anterior approach, due to the superomedial obliquity of the trajectory. The ARPA avoids the potentially contaminated oropharyngeal cavity providing for a simultaneous arthrodesis and instrumentation during the primary surgical procedure. Experience of five patients with high cervical extradural compression, who underwent surgery using this approach between 1994 and 1999, is presented. The surgical procedures included excision of ossified posterior longitudinal ligament (n=2); excision of prolapsed disc and osteophytes (n=2); and excision of a vertebral body neoplasm (n=1). Following the procedure, vertebral arthrodesis was achieved using an iliac graft in all the patients. Only one patient with vertebral body neoplasm required an additional anterior cervical plating procedure for stabilisation the construct. The complications included transient respiratory insufficiency and neurological deterioration in two patients; and, pharyngeal fistula and donor site infection in one patient.

Adult↗

PubMed2001

Medulloblastomas of the cerebellopontine angle.

It is unusual for a medulloblastoma to occur in the cerebellopontine angle (CPA). Four of the total 63 cases of medulloblastoma managed in our department between 1988 to 1998, presented with a mass in the cerebellopontine angle. There were two children amongst these four patients, aged eight and nine years. The other two patients were young adults. Three patients had primary CPA medulloblastoma, while the fourth case had a recurrence in this region, following the excision of the primary vermian tumour. All the four cases were managed by gross total microsurgical excision and craniospinal irradiation. One of the two children, developed subfrontal recurrence after 1 year and 8 months of initial treatment, while the other child developed a large recurrence at primary site, within three months of post-operative irradiation. However, the adult patient developed CPA recurrence and subsequent cervical intramedullary metastasis within two and a half years of diagnosis. These three cases succumbed to their disease, between three months to thirty months of their initial management. However the fourth patient, a 20 years female with desmoplastic variant, was well at two and a half years of follow up.

Adult↗

PubMed2000

Brain stem tuberculosis in children.

Tubercular meningitis and intracranial tuberculomas are the two frequent manifestations of neurotuberculosis with their variable incidence in different countries. Brain stem tuberculomas are even more unusual, accounting for 2.5-8% of all intracranial tuberculomas. We present here six paediatric cases of brain stem tuberculosis, where well-formed tuberculomas were demonstrated in five symptomatic cases; however, only a hypodense ill-defined lesion was found in the brain stem of one child who presented with features of tubercular meningitis. Three of these children had other associated tuberculomas in their brain parenchyma as well. All the six cases, however, showed the involvement of 3rd, 6th & 7th cranial nerves, in various combinations, at the time of initial presentation. Only two children developed hydrocephalus and required CSF diversion. All responded well to anti-tubercular chemotherapy, though two children developed toxicity to the therapy, which recovered with drug manipulation for about 2 months. Recovery was full without residual deficit in all the cases. Surgical excision of brain stem granulomas was not indicated in any case.

Brain Stem↗

PubMed2000

C1-C2 rotary subluxation following posterior stabilization for congenital atlantoaxial dislocation.

The authors report a rare complication of C1-C2 rotary subluxation in two children following posterior stabilization for congenital atlantoaxial dislocation (AAD). A patient, with mobile AAD, underwent Brook's C1-C2 fusion while the other, with fixed AAD, underwent transoral decompression followed by Jain's occipitocervical fusion. A pre-existing ligamentous laxity associated with an asymmetrical wire tightening or slippage of the wires due to rotation of the neck in the former, and the drilling of the C1-C2 lateral joints during the transoral procedure in the latter, could have contributed to the rotary subluxation. Both patients presented with persistent torticollis due to fusion in an asymmetrical position with dislocated facet joints. Rotary C1-C2 subluxation, when coexisting with anterior dislocation, has the potential to cause severe and occasionally fatal cord compression. Well defined criteria to diagnose this entity by conventional radiology exist, however, due to the overlap of anatomy, the condition is often overlooked. In the present study, three dimensional reconstruction images using helical computerized tomography were very useful in delineating the subluxation and in planning its surgical reduction and arthrodesis.

Adolescent↗

PubMed2000

Infected Ewing's sarcoma of spine.

An unusual case of extradural, intraspinal Ewing's sarcoma with significant extraspinal extension is reported. In view of associated constitutional symptoms, suggestive signs, leucocytosis, elevated ESR and operative findings, the initial diagnosis of Pott's spine was entertained. The lesion however turned out to be infected Ewing's sarcoma on histopathology and bacteriological examination.

Child↗