Raj Kumar

Serial changes in the white matter diffusion tensor imaging metrics in moderate traumatic brain injury and correlation with neuro-cognitive function.

Diffuse axonal injury (DAI) that follows traumatic brain injury (TBI) is thought to be a major contributor to neurocognitive dysfunction that sometimes follows TBI. Conventional magnetic resonance imaging (MRI), diffusion tensor imaging (DTI) and neuropsychological tests (NPT) were performed on 38 TBI patients [hemorrhagic DAI (H-DAI, n=8), non-hemorrhagic (Nh-DAI, n=7), with no apparent DAI on conventional MRI (NA-DAI, n=23)] with a Glasgow Coma Scale score ranging between 9 and 13. The fractional anisotropy (FA) and mean diffusivity (MD) were quantified from different regions of the corpus callosum (CC), and peri-ventricular white matter (PWM) within 5-14 days and 6 months following TBI. Patients in all three groups showed decreased FA in the anterior limb of the internal capsule (ALIC) and the posterior limb of the internal capsule (PLIC), while the genu of the CC showed a decrease in the H-DAI group during the early period following TBI that persisted 6 months later, which appeared to be consistent with axonopathy. In patients without abnormalities on conventional MRI and DTI in the initial phase, a significant decrease in FA and increase in MD were observed in a few regions of the CC at 6 months, which was suggestive of demyelination/gliosis. The changes in FA and MD in the CC and PWM at 6 months follow-up showed significant correlation with some of the NPT performed in the three groups. DTI demonstrates axonopathy in the acute stage, as well as at secondary stages, at 6 months post-injury in the CC and PWM in regions of normal-appearing white matter on conventional MRI.

Comparative evaluation of corpus callosum DTI metrics in acute mild and moderate traumatic brain injury: Its correlation with neuropsychometric tests

Primary objective: To look for differences in vulnerability of corpus callosum (CC) in patients of mild and moderate traumatic brain injury (TBI) in the acute stage using quantitative diffusion tensor imaging (DTI) and to correlate these with neuropsychometric tests (NPT) done at 6 months post-injury. Research design, methods and procedures: Conventional MRI, DTI and NPT were performed on 83 patients (moderate TBI, n = 57; mild TBI, n = 26) within 5–14 days after TBI. Thirty-three age- and sex-matched healthy controls were also included for comparison. Results: Significantly decreased fractional anisotropy (FA) in genu and splenium; significantly increased radial diffusivity (RD) values in genu, midbody and splenium with significant increase in mean diffusivity (MD) and a decrease in axial diffusivity (AD) only in genu, respectively, in patients with moderate TBI compared to healthy controls were observed. However, in moderate TBI, significantly decreased FA was found only in genu compared to mild TBI. Moderate TBI showed poor NPT scores compared to mild TBI, but this did not reach statistical significance. Conclusions: It is concluded that DTI abnormalities in the regions of CC were more in patients with moderate TBI compared to mild TBI and this was associated with relatively poor neuropsychological outcome 6 months post-injury.

Tuberculous brain abscess: clinical presentation, pathophysiology and treatment (in children)

HeadingAbstract Background. Tubercular brain abscess (TBA) is a rare manifestation of CNS tuberculosis. It is characterised by an encapsulated collection of pus, containing viable tubercular bacilli without evidence of tubercular granuloma. Presentation and history. Patients may present with features of raised intracranial pressure and focal neurological deficit commensurate with the site of the abscess. A history of pulmonary tuberculosis may be present, as documented in one of our six cases; three of our six children developed TBA despite 3-weeks to 12-month courses of antitubercular chemotherapy prescribed for post-TBM hydrocephalus. Diagnosis. Contrast CT head, MRI, MR spectroscopy is helpful in making the diagnosis and planning the treatment. TBA may be unilocular or multilocular on contrast CT scan. A relatively long clinical history and an enhancing capsule with thick wall are suggestive of TBA. Pyogenic abscess, however, has a thin rim on contrast CT. The capsule of TBA is formed of vascular granulation tissue containing acute and chronic inflammatory cells, particularly polymorphs. Proof of tubercular origin must be demonstrated either by presence of acid fast bacilli in culture or staining of pus or wall. Treatment. Treatment options include simple puncture, continuous drainage, fractional drainage, repeated aspiration through a burr hole, stereotactic aspiration and total excision of the abscess. Total excision usually becomes necessary in multilocular noncommunicating and thick-walled abscesses. Antitubercular therapy is the mainstay of management. The development of fulminant tubercular meningitis is sometimes problematic following surgical excision of TBA, as seen in one of our four operated cases. Mortality is reported to be high despite progress in treatment, while five of the six children treated by us responded well to the treatment.

Spinal Dysraphism: Trends in Northern India

Objective: To evaluate the clinical profiles, image findings and surgical outcome of 155 cases of spinal dysraphism. Methods: 155 patients were studied prospectively (143) or retrospectively (12). The male to female ratio was 1.5:1. Mean age at presentation was 5.7 years. Out of 155 cases of spinal dysraphism, 119 had open spina bifida [meningomyelocele (MMC) in 113 (72%), meningocele in 3 (2%) and myelocystocele in 3 (2%)] and 36 had occult spina bifida [split cord malformation (SCM) without overt MMC sac (pure SCM) in 29 (19%) and midline dermal sinus in 7 (4.5%)]. Lipomeningomyelocele constituted 73 of the 113 cases of MMC (65%). Twenty cases of MMC (18%) had associated SCM (complex spina bifida). The total number of cases with SCM was 49 (32%). Twenty-four children with MMC presented with an operative scar from previous surgery, performed at the periphery. After a detailed clinical evaluation of all patients, craniospinal MRI was the preferable mode of investigation. All patients underwent surgery and were clinically assessed over a mean follow-up period of 3.6 years. Results: MMC sac was the commonest skin manifestation seen in 89/155 cases (57%). Hypertrichosis and previous operative scar were noticed in 24 cases each (15%). Cutaneous hemangioma, skin tag and multiple neurofibroma were the other common superficial skin manifestations. Clinically, 103 patients (66.5%) had variable weakness of the lower limbs, and muscle atrophy was noticed in 56 cases (41%). Graded sensory loss, sphincteric dysfunction, trophic ulcer and backache were present in 89 (57%), 64 (36%), 17 (11%) and 9 cases (6%), respectively. Significant scoliosis in 56 cases (36%) and congenital talipes equinovarus in 51 cases (33%) were the most frequent neuroorthopedic deformities apart from high-arched foot, leg length discrepancy and flat foot. Common image findings were low-lying cord in 101 (65%), neural placode in 76/113 (49%), hydrosyrinx in 42 (27%), hydrocephalus in 71 (46%) and Chiari malformation in 62 cases (45%). The lumbosacral region in 56 cases (38%), followed by the lumbar region in 47 (30%), were the most common sites of occurrence of spina bifida. Of 71 hydrocephalic patients, 39 (55%) needed shunting before definitive surgery and 21 (30%) after the surgery. Eleven patients (15%) did not require shunting at all. CSF leak in 51 patients (33%), pseudomeningocele in 26 (17%), wound infection in 22 (14%) and meningitis in 13 (8%) were the most common postoperative complications. Two patients died in the postoperative period. During an average follow-up of 3.6 years (range 1.5–8 years), motor weakness improved in 47 children (45%) and remained static in 53 (52%), and 3 children showed deterioration in motor power. Sensory dysfunction improved in 43 (48%), remained static in 42 (47%) and deteriorated in 4 patients (4%). Sphincteric function clinically improved in 26 patients (41%) and was static in 38 (59%), and 6 patients (4%) had deterioration. Backache was dramatically relieved in all 9 patients with this complaint (100%). In 13 children with trophic ulcer (76%), it completely healed. Conclusion: A significant proportion of patients with open spinal dysraphism harbor an underlying SCM, an entity coined complex spina bifida (in our previous study). The incidence of hydrocephalus in spinal dysraphism is low in India in comparison to the Western world. Some patients with mild hydrocephalus on scan may not require a shunt operation. Surgical intervention should be early after entire neural axis screening by MRI.

Effect of spinal cord signal intensity changes on clinical outcome after surgery for cervical spondylotic myelopathy

OBJECT The presence of intramedullary T2 high signal intensity changes in patients with cervical spondylotic myelopathy (CSM) indicates the existence of a chronic spinal cord compressive lesion. However, the prognostic significance of signal intensity changes remains controversial. The purpose of this study was to evaluate the effect of spinal cord T2 signal intensity changes on the outcome after surgery for CSM. METHOD In a prospective study, 64 patients with CSM who underwent surgical treatment between October 2006 and April 2008 using an anterior approach were included. Based on the clinical symptoms and signs present, the severity of neurological deficits of all patients was scored according to a modified Japanese Orthopaedic Association scale score for CSM just before the surgery and at 6 months follow-up. Recovery rates were calculated at 6 months. RESULTS There were 22 patients who did not have spinal cord intensity changes on MR imaging and 44 who demonstrated high-intensity signal changes on T2-weighted images (focal or segmental). No statistically significant differences were found in recovery rates between cases with T2 signal intensity changes and those with no signal intensity changes. However, the postoperative modified Japanese Orthopaedic Association scale scores and the recovery rates were much lower in patients with multisegmental signal intensity changes compared with those without these changes or those with focal signal intensity change, and ANOVA demonstrated this difference to be statistically significant (p < 0.05). CONCLUSION Multisegmental spinal cord signal intensity changes on T2-weighted MR imaging are predictors of a poor outcome in terms of functional recovery rate in patients undergoing operations for CSM.

Occurrence of Split Cord Malformation in Meningomyelocele: Complex Spina bifida

Objective: To describe the clinical features and surgical outcome of a combined anomaly, i.e. split cord malformation (SCM) with meningomyelocele (MMC), and to propose an addition to Pang’s classification of SCM to accommodate a combined form of anomaly. Methods: We retrospectively analyzed 16 cases of such a combination, out of a total of 106 cases of spinal dysraphism treated and studied prospectively for outcome at our center. The clinical profile and outcome of these cases are described. Results: All cases had SCM and MMC. Nine patients were males, and the mean age of presentation was 3.9 years. Twelve patients had Pang’s type I SCM and the other 4 were of type II. The MMC sac was lumbar in 11 cases. In all the patients, SCM was present either at the same level as the MMC or one to two segments above it. Nine patients had motor weakness, 6 had hypoesthesia, 4 had urinary incontinence and 3 had trophic ulcers. Nine patients had neuroorthopedic syndrome. All cases, except 3 (who were operated on at birth, at which time ‘superficial surgery’ was performed without relevant imaging), underwent repair of the MMC and excision of the spur/septum at the same sitting. The 3 cases who had undergone superficial surgery, however, were operated on for SCM following investigation at our center, obviously at a second sitting. After an average follow-up of 7.2 months, 4 patients showed improvement in motor weakness, 5 in hypoesthesia and 3 in urinary symptoms, whereas trophic ulcers had healed in all cases. Conclusion: With respect to the occurrence of SCM at or above the level of an MMC, we feel it is apt to screen the entire spinal/neuraxis by MRI in children with MMC. We labeled this combined pathology ‘complex spina bifida’, and feel it is necessary to make a minor modification to Pang’s classification to accommodate the pure/combined anomalies together.

Serial changes in diffusion tensor imaging metrics of corpus callosum in moderate traumatic brain injury patients and their correlation with neuropsychometric tests: a 2-year follow-up study.

ObjectiveTo assess longitudinally the severity of diffuse axonal injury in the corpus callosum in patients with moderate traumatic brain injury (TBI) through quantitative diffusion tensor imaging and to correlate these changes with neuropsychometric tests (NPT) at 6 and 24 months after injury. DesignProspective longitudinal study. ParticipantsSixteen patients with TBI and 17 age/sex-matched healthy controls. MethodsPatients underwent magnetic resonance imaging at 3 time points: within 2 weeks (range = 5–14 days), 6 months, and 24 months after injury. NPT could be performed only at 6 and 24 months. ResultsIn patients with TBI, a significant increase in fractional anisotropy (FA) values in genu as well as an insignificant decrease in radial diffusivity (RD) and mean diffusivity values in genu and splenium were observed over time, respectively. FA, RD, and mean diffusivity values continued to be abnormal in patients compared with controls at the end of 2 years. Although some NPT scores improved over time in these patients, these were still significantly impaired compared with controls. ConclusionsFA and RD indices appear to be surrogate markers of microstructural alterations in patients over time and correlate significantly with some of the NPT scores. The recovery in these indices associated with recovery in neurocognitive deficits suggests that these indices may be used as an objective marker for residual injury in these patients.

Primary Spinal Primitive Neuroectodermal Tumor: Case Series and Review of the Literature

Primary spinal primitive neuroectodermal tumor (PSPNET) is extremely rare and only 25 cases have been reported in the world literature so far. Three patients of 8, 9 and 18 years of age, who presented with variable grades of neurological deficit were diagnosed as having a dorsal intramedullary lesion, a holocord lesion and cervical extradural tumor with extraspinal extension, respectively, and were operated at our institute. The histopathology of all 3 children revealed PNET. The clinical course, image characteristics and outcome of the 3 children are described, and the relevant literature is reviewed. The following conclusions were drawn from the present study and review of the literature. PNET may manifest itself as a primary lesion of the spine unlike the more common drop metastases from an intracranial lesion. PSPNET may be intramedullary, intradural and extradural with variable extraspinal extension. PSPNET may present as holocord intramedullary lesion, an entity which has not been described earlier. These lesions have a short history, significant neurological deficits and rapid course of illness. PSPNET, though an established entity, did not find a place in the WHO 2000 classification of CNS tumors. Hence its status has to be defined.

Subependymal giant cell astrocytoma: a report of five cases

Five cases of intraventricular subependymal giant cell astrocytomas (SEGCA) were retrospectively reviewed. Records and detailed work-up of all five cases were well maintained in view of rare occurrence of these tumors. The five patients were males aged 10, 12 (2 cases), 14 and 18 years. The 18-year-old aged male had no stigmata of tuberous sclerosis (TSC) on examination, while the rest presented with features of TSC, intraventricular tumors and hydrocephalus. None of the five cases had renal tumors and did not reveal cardiac tumors. Skin manifestations like shagreen patches were present in two, facial angiofibromas in three, periungal fibromas in two, hypopigmented macules in two and ash-leaf spot in two patients. Fundoscopic examination revealed retinal astrocytomas in two cases only. Two of the five children did not have mental compromise. A child who started throwing seizures early (at 5 months of age) had severe mental retardation. Although SEGCA is a less vascular tumor, one tumor bled profusely intraoperatively; it was excised rapidly via the transcortical route to salvage the life of the child, though he was planned for the transcallosal route like the other cases. The tumor of another child was also very vascular. Four children survived surgery and required no shunt CSF diversion, while one died of severe ventriculitis and septicemia 3 weeks after surgery.

Paradoxical response to chemotherapy in neurotuberculosis

Objective: Our objective was to investigate the paradoxical response and the factors responsible for such an uncommon (but known) response to chemotherapy in neurotuberculosis. Material and Methods: Ten children with intracranial tuberculomas/neurotuberculosis were retrospectively studied, who were on regular antituberculous chemotherapy. Any deterioration of the neurological condition, increase in the size of the lesion or appearance of new lesions was studied clinically and radiologically during the follow-up period. Results: An atypical response to chemotherapy was observed from 3 weeks to 1 year of chemotherapy. Four of the 10 children, who were receiving chemotherapy for either posttubercular meningitis (TBM), hydrocephalus (2) or TBM (2), developed multiple granulomas in 3 and hydrocephalus in 1 case. The remaining 6 children who were diagnosed to have granulomas at their presentation deteriorated at the follow-up despite regular chemotherapy. CT scans were repeated in 7 of 10 cases at the time of neurological deterioration, out of which 5 children showed appearance of new granulomas or abscess(es) and 2 showed an increase in the size of their preexisting granulomas. One patient with faintly enhancing granulomas in the posterior fossa responded to an additional use of steroids. The remaining 9 patients required surgical intervention on account of their neurological deterioration. Conclusions: (1) Paradoxical responses to intracranial tuberculoma/neurotuberculosis can occur at any time even up to 1 year during chemotherapy despite a regular standard antitubercular treatment. (2) New granuloma(s) or abscess(es) may appear in children receiving chemotherapy for TBM during the follow-up. (3) Hydrocephalus may also appear despite a regular chemotherapy in treated TBM cases. (4) Immature faintly enhancing tuberculomas have a more likely chance of resolution with antituberculous chemotherapy and glucocorticoids, while a well-formed and probably large-sized (>3 cm) granuloma may have a risk of paradoxical enlargement.