Nalin K. Mishra

Bipartite atlas with os odontoideum: case report.

Study Design. A case report of bipartite atlas associated with os odontoideum and review of the pertinent literature are presented. Objective. To illustrate an unusual association of bipartite atlas and os odontoideum and explain the embryological basis. Summary of Background Data. To the authors’ knowledge, only one case of bipartite atlas with os odontoideum had been reported previously. Most of the previously reported cases of bipartite atlas are asymptomatic. Methods. A 16-year-old boy presented with a 2-month history of weakness and numbness of all four limbs after sustaining a minor head trauma. Radiographs of cervical spine revealed aplasia of anterior arch of atlas, ventral displacement of C1 over C2 on flexion, which reduced on extension. CT scan showed anterior arch aplasia, posterior arch midline defect, and os odontoideum, which had a small projection on the anterior surface at the level of anterior arch. MRI demonstrated increased cord signal at C1–C2 levels on T2-weighted image. Transoral odontoidectomy and posterior fixation of occiput with C2–C3 spinous processes was performed. Results. The patient had significant improvement over next 3 months. Conclusions. We described a rare association of an anterior arch aplasia, posterior arch defect and os odontoideum. The natural history of patients with os odontoideum suggests that these people have a potentially precarious existence.

Distraction, compression, and extension reduction of basilar invagination and atlantoaxial dislocation: a novel pilot technique.

BACKGROUND The management of basilar invagination (BI) and atlantoaxial dislocation (AAD) is a challenge. OBJECTIVE To describe a new innovative method to reduce BI and AAD through a single-stage posterior approach. METHODS Thirty-five patients had irreducible BI and AAD (May 2010 to April 2012). In all patients, reduction of AAD and BI was achieved by using an innovative method of distraction and spacer placement, followed by compression and extension. A C1 lateral mass/C2 translaminar screw was performed in cases where the C1 arch was not assimilated, and occipito-C2 translaminar screw fixation was performed in cases where the C1 arch was assimilated. RESULTS Thirty-two of 35 (94%) patients improved clinically and 2 patients had stable symptoms (mean Nurick postoperative score = 1.4; preoperative score = 3.7). AAD reduced completely in 33/35 patients and >50% in 2. BI improved significantly in all patients. Solid bone fusion was demonstrated in 24 patients with at least 1-year follow-up (range, 12-39 months; mean, 19.75 + 7.09 months). The duration of surgery was 80 to 190 minutes, and blood loss was 90 to 500 mL (mean, 170 ± 35 mL). There was 1 death because of cardiac etiology and 1 morbidity (wound infection). CONCLUSION Distractive compressive extension and reduction of BI and AAD seems to be an effective and safe method of treatment. It is different from the earlier described techniques, because it is the first procedure that uses a spacer not, only for distraction, but also as a pivot to perform extension to reduce the AAD.

Association of craniovertebral and upper cervical anomalies with dermoid and epidermoid cysts: report of four cases.

OBJECTIVE AND IMPORTANCE:Four patients with craniovertebral junction anomalies (CVJ) and Klippel-Feil cervical fusion defects associated with dermoid and epidermoid cysts are described. CLINICAL PRESENTATION:During the 10-year period from 1994 until May 2004, 435 patients with developmental CVJ anomalies presented to our institution. Four of these patients harbored a constellation of CVJ anomalies with dermoid and epidermoid cysts (hospital prevalence, 0.9%). All patients (ages 18, 23, and 25 yr) presented with features of spastic quadriparesis, restriction of neck movements, and raised intracranial pressure. Magnetic resonance imaging showed features of CVJ anomalies in all patients (occipitalization of C1, 3 patients; basilar invagination, 3 patients; atlantoaxial dislocation, 4 patients; and an abnormal posteriorly pointed dens, 1 patient), along with a Klippel-Feil anomaly (Patients 1–3, 2nd and 3rd cervical vertebrae). Patient 4 also had a Chiari malformation with syrinx. In addition, all four patients had coexisting dermoid or epidermoid cysts (Patients 1 and 3, midline posterior fossa epidermoid; Patient 2, midline posterior fossa dermoid; Patient 4, quadrigeminal cistern epidermoid). INTERVENTION:Patients 1 and 2 underwent a posterior midline approach, excision of the tumor, and an occipitocervical fusion (the atlantoaxial dislocation was reducible). Patient 3 underwent transoral excision of the odontoid, followed by tumor excision and occipitocervical fusion via the posterior route. These patients had uneventful recovery. Patient 4 did not undergo an operation. CONCLUSION:Association of CVJ anomalies with Klippel-Feil and dermoid and epidermoid cysts is extremely rare, with only two previously reported cases. The patient who presented with a quadrigeminal cistern epidermoid with a craniovertebral junction anomaly and Chiari malformation with syrinx is the first such case ever reported in the literature. Apart from therapeutic implications, these patients may shed new light on the embryogenesis. Furthermore, the gathering of these manifestations may constitute components of a new syndrome that has gone unnoticed until now.

Treatment of Vertebral Hemangiomas With Absolute Alcohol (Ethanol) Embolization, Cord Decompression, and Single Level Instrumentation: A Pilot Study

BACKGROUND:Vertebral hemangiomas (VH) are the most common lesions of the vertebral column. OBJECT:To evaluate the role of intraoperative ethanol embolization, surgical decompression, and instrumented fusion in VH presenting with myelopathy. METHODS:This is was a prospective study of single-level symptomatic VH with cord compression. Exclusions were as follows: pathological fractures, deformity, or multilevel pathologies. Surgery consisted of intraoperative bilateral pedicular absolute alcohol injection and laminectomy at the level of pathology followed by a short-segment instrumented fusion using pedicle screws. RESULTS:Ten patients (mean, 26.8 ± 18.11; range, 10-68 years; 8 females) were treated with use of this technique. Clinical features included myelopathy with motor and sensory involvement in all (4 paraplegic), sphincter involvement (8), and severe local pain (5). The preoperative American Spinal Injury Association (ASIA) scores were A (3), B (1), and C (6). All had pan vertebral body VH with severe cord compression. The mean surgical time was 102 ± 22 minutes; average blood, 296 ± 90.82 mL. Mean amount of absolute alcohol injected was 12.6 ± 4.7 mL (1 requiring 25 mL). Immediate embolization was achieved in all patients allowing laminectomy and soft-tissue hemangioma removal. Postsurgery, all patients showed improvement (sphincters improved in 4) at a follow-up ranging 12 to 26 months (transient neurological deterioration in 1). Postsurgery ASIA scores were D (5) and E (5) at last follow-up. Two patients showed evidence of bone sclerosis on follow-up CT scans at 1.2 and 1.5 years. CONCLUSION:This procedure seems to be a safe, efficient method to treat VH with severe cord compression. It seems to serve the purpose of providing embolization, cord decompression, and rigid fusion at the same sitting.

In reply: distraction, compression, and extension reduction of basilar invagination and atlantoaxial dislocation.

1. Chandra PS, Kumar A, Chauhan A, Ansari A, Mishra NK, Sharma BS. Distraction, compression, and extension reduction of basilar invagination and atlantoaxial dislocation: a novel pilot technique. Neurosurgery. 2013;72(6):1040-1053. 2. Yin YH, Yu XG, Zhou DB, et al. Three-dimensional Configuration and Morphometric Analysis of the lateral atlantoaxial Articulation in Congenital Anomaly with Occipitalization of the atlas. Spine (Phila Pa 1976). 2012;37(3):E170-E173. 3. Goel A. Goels classification of atlantoaxial “facetal” dislocation. J Craniovert Jun Spine. 2014;5:3-8.

Fourth Ventricular Hamartoma Presenting with Status Epilepticus Treated with Emergency Surgery in an Infant

A 4-week-old infant presented with hemifacial spasms noticed from the 4th day after delivery. These progressed in severity, with generalization every 3–4 h. On admission, the infant went into refractory status epilepticus and had to be electively ventilated and taken for surgery on a semi-emergency basis. MRI showed a fourth ventricular hamartoma and video EEG showed spikes that were synchronous with the facial ‘twitches’ with generalization. Following the first surgery, the infant had an initial complete recovery, but developed recurrence of facial twitches after 2 weeks. Repeat MRI showed a small residual tumor which was re-operated and completely excised (at 8 weeks). Following this, the patient had complete recovery from seizures (5-year follow-up). This is the youngest patient reported presenting with status epilepticus with a fourth ventricular hamartoma operated successfully.

Imaging appearances of meningeal melanocytoma.

Meningeal melanocytoma is an uncommon, benign melanocytic tumour of the meninges. Only 15 cases have been reported to date. We present the MR and CT appearance of a case of compressive myelopathy due to cervical meningeal melanocytoma. Careful analysis of the imaging features, as illustrated in the present case, allows a preoperative diagnosis. The differential diagnosis includes malignant melanoma and melanocytic meningioma.

Congenital maldevelopment of intervertebral disc simulating a neurofibroma

Abstract Intervertebral disc herniation is a common cause of radiculopathy and myelopathy in adulthood. It is an uncommon tumor mimic. We report on an extradural disc associated with an osseous defect ostensibly caused by pressure erosion and appearing as a neural tumor. It showed homogeneous enhancement on a contrast-enhanced MR examination, leading to an erroneous diagnosis of nerve sheath tumor. An attempt has been made to explain the likely mechanism of formation accounting for the imaging appearances, along with a review of the literature.