Nitin Dange

Retrospective analysis of peripheral nerve sheath tumors of the second cervical nerve root in 60 surgically treated patients.

OBJECT This study is a retrospective analysis of 60 surgically treated patients with 64 peripheral nerve sheath tumors (PNSTs) at the second cervical (C-2) nerve root. The anatomical subtleties of these tumors and their implications for surgical strategy when compared with other spinal PNSTs and other tumors in the foramen magnum region are reviewed. METHODS Sixty patients with C-2 PNSTs treated surgically in the Department of Neurosurgery at King Edward VII Memorial Hospital and Seth Gordhandas Sunderdas Medical College between 1992 and 2006 were studied. All patients underwent magnetic resonance imaging. Tumors were divided into 3 groups depending on their anatomical location identified during surgery. Those tumors located within or extending into the spinal dural tube were called Type A, those located within the dural tube of the C-2 ganglion were labeled as Type B, and tumors extending laterally into the paraspinal region were labeled as Type C. Follow-up durations ranged from 6 months to 15 years (mean 64 months). RESULTS There were 38 male and 22 female patients in the study, who ranged in age from 6 to 62 years (mean 28 years). Nine patients had clinical features indicative of neurofibromatosis (NF). The mean duration of symptoms at the time of presentation was 27 months (range 4 days-5 years). Two patients had no specific symptoms related to the C-2 PNST, 6 patients had only local symptoms such as neck pain or stiffness, and 52 patients had symptoms of varying degrees of myelopathy. There were 5 solely Type A tumors, 7 Type A + B tumors, 31 Type B tumors, and 21 Type B + C tumors. All Type A, A + B, and B tumors were totally resected. Seven of 21 Type B + C tumors were partially resected, and the remainder were completely resected. All patients postoperatively reported varying improvement in their preoperative symptoms. Except for patients with NF who were disabled by other tumors, the rest of the patients resumed their normal life style. There have been no cases of symptomatic tumor recurrence. CONCLUSIONS The majority of PNSTs located at the C-2 level in these patients probably arose from the large C-2 ganglion and are limited within the dural confines or are interdural in location. In contrast to other spinal PNSTs, the location of C-2 PNSTs is in most cases posterior to the lateral mass of the atlas and axis and the atlantoaxial joint and is exposed to the posterior without any bone cover. Radical tumor resection is safe, resolution of clinical symptoms is rapid, and recurrence rates are extremely low. In a selected number of cases, bone work for tumor exposure and resection can be entirely avoided.

Fiber dissection of the visual pathways: Analysis of the relationship of optic radiations to lateral ventricle: A cadaveric study

OBJECTIVE Using a fiber-dissection technique, our aim is to study the fiber bundles of the optic radiation. We focused on the course, the length, anatomical relations with lateral ventricle and the relevance of these finding during surgery in the region. MATERIALS AND METHODS Five previously frozen and formalin-fixed cadaveric human brains were used. The dissection was done using the operating microscope. Fiber dissection techniques described by Klingler were adopted. The primary dissection tools were handmade, thin, and wooden and curved metallic spatulas with tips of various sizes. Lateral and inferior temporal approaches were made and the optic fiber tracts were dissected. RESULTS Resections that extend through the roof of the temporal horn more than 30 mm behind the temporal pole cross the Meyers loop. In the middle temporal gyrus approach, resection that is taken through the lateral wall of the temporal horn more than 55-60 mm behind the temporal pole may cross the optic radiation during their course here on the lateral wall. CONCLUSION The presented fiber dissection study clarifies the relationship of optic radiation. Such fiber dissection studies are only few in the literature.

Techniques in the treatment of craniovertebral instability

The techniques of craniovertebral region stabilization introduced and used by the senior author over the last 20 years are summarized. The lateral masses of atlas and axis are strong and largely cancellous in nature and can be used for direct implantation of screws. Opening up of the joint and placement of bone graft within the joint stabilizes the region and provides a large area for bone fusion. Distraction of the facets provides an opportunity to treat a range of congenital craniovertebral anomalies. The technique of exposure of the lateral mass of the atlas and axis and the atlantoaxial joint is technically relatively complex and needs precise understanding of anatomy of the vertebral artery and training with cadavers.

Cranial migration of complete ventriculo-peritoneal shunt assembly

A 10-month-old male child with severe congenital hydrocephalus due to aqueduct stenosis presented with cranial migration of the entire ventriculo-peritoneal (VP) shunt. The complete shunt assembly, including the shunt chamber, was noted in the dilated ventricles. The migrated shunt was left in situ. A VP shunt was performed on the opposite side. The complete intraventricular migration of a VP shunt is a rare complication. This complication may be avoided by firm anchoring of the connector sites to the periosteum, and avoidance of large burr holes and dural openings. The possible mechanisms of such an event and the relevant literature are discussed.

Dolichoectasia of vertebrobasilar arteries as a cause of hydrocephalus

Dolichoectasia of vertebrobasilar artery is a condition in which the vertebral/basilar artery is elongated, distended and tortuous. It is usually asymptomatic. It may present with compressive or ischemic symptoms. Hydrocephalus as a complication of vertebrobasilar dolichoectasia is rare. We present a case of a 60-year-old male with dolichoectasia of the basilar artery causing compression of the third ventricular outflow and, thus, presenting with noncommunicating hydrocephalus.

Ruptured giant dermoid cyst of the cavernous sinus

We report a 27-year-old male with a giant dermoid cyst of the cavernous sinus that extended into the posterior fossa and ruptured, causing meningitis and hydrocephalus. We also discuss the radiological features, surgical challenges and management difficulties of such a cyst. A giant dermoid cyst of the cavernous sinus that extends into the posterior fossa and subsequently ruptures has not been previously reported.

Diencephalic juvenile pilomyxoid astrocytoma with leptomeningeal dissemination.

Pilomyxoid astrocytoma (PMA) is a recently described neoplasm. PMA shares few features with pilocytic astrocytoma (PA), the most common central nervous system (CNS) tumor in the pediatric population, yet displays histological differences. Previous studies have shown that PMAs have more aggressive biological behavior as compared to PA. These findings suggest that PMA may be a unique and distinct neoplasm. We report a pilomyxoid astrocytoma of the hypothalamic-chiasmatic region with leptomeningeal dissemination in a 3-month old infant. This case report discusses the histological, clinical, and radiographic characteristics of PMA. In addition, the current treatment options and research potential involving this disease are also briefly described.

Fat graft migration causing recurrent cervical cord compression.

AIM Fat graft migration following spinal cord surgery is an uncommon problem. Only few cases of fat graft migration causing cauda equine syndrome, recurrent sciatica, and root compression following lumbar spine surgery have been reported. We report a case of fat graft migration causing symptomatic cervical cord compression. MATERIAL AND METHODS A 45-years-old male with cervical spondylosis underwent anterior C4-5 discectomy and excision of hypertrophied ligament. A dural tear that occurred during the procedure was repaired with fat graft harvested from thigh. Significant improvement in stiffness was noted postoperatively. After 15 days, the patient presented again with worsening lower limbs stiffness. Magnetic resonance imaging of spine was done which revealed displacement of the fat graft causing cervical cord compression. RESULTS Re-exploration was done and the migrated fat graft was removed. Post operatively patient noticed significant improvement in stiffness in both lower limbs. CONCLUSION Autologous fat graft is one of the best materials used in sealing the dural cerebrospinal fluid leak during spinal surgery. However sometimes it may migrate and cause compression of cord and roots with relative symptoms. This complication should be kept in mind as removal of migrated fat graft will relieve these symptoms.

Giant intramedullary epidermoid extending from the brain stem to the upper thoracic spinal cord.

Epidermoid cysts are benign tumors originating from ectoderm remnants. Most epidermoid cyst cases are intracranial. Spinal epidermoid cysts are uncommon and most of the reported cases are in the thoracic and lumbar spine. Occurrence of intramedullary epidermoid cysts in the cervical spine is extremely rare. An 18-year-old male with a giant intramedullary tumor extending from the brain stem to the upper thoracic spinal cord presented at our outpatient department. The patient underwent total excision of a silvery white lesion through a midline myelotomy. Histopathological examination was suggestive of an epidermoid cyst. We present a brief report of the case and discuss the relevant literature.

Primary amenorrhea due to empty sella: an underestimated entity.

We report a 16-year-old girl who had stunted growth and primary amenorrhea presenting with headache and vomiting. MRI of brain showed posterior fossa dermoid cyst with hydrocephalus and empty sella. Growth hormone (GH), Leutinizing hormone (LH) and Follicular stimulating hormone (FSH) were grossly reduced on endocrinological work-up. She underwent suboccipital midline craniectomy and complete excision of dermoid cyst .She had no additional deficit after the surgery. She had menarche six months after the surgery and developed adequate secondary sexual characters, however her height remains subnormal at follow-up after 2 years as compared to age matched controls. We briefly review the radiological features, pathogenesis and outcome of this underestimated entity.