Sameer Futane

Operative nuances to safeguard anomalous vertebral artery without compromising the surgery for congenital atlantoaxial dislocation: untying a tough knot between vessel and bone

OBJECT Stabilization of the craniovertebral junction (CVJ) by using lateral masses requires extensive dissection. The vertebral artery (VA) is commonly anomalous in patients with congenital CVJ anomaly. Such a vessel is likely to be injured during dissection or screw placement. In this study the authors discuss the importance of preoperative evaluation and certain intraoperative steps that reduce the chances of injury to such vessels. METHODS A 3D CT angiogram was obtained in 15 consecutive patients undergoing surgery for congenital atlantoaxial dislocation. The course of the VA and its relationship to the C1-2 facets was studied in these patients. The anomalous VA was exposed intraoperatively, facet surfaces were drilled in all, and the screws were placed according to the disposition of the vessel. RESULTS A skeletal anomaly was found in all 10 patients who had an anomalous VA. Four types of variations were noted: 1) the first intersegmental artery in 5 patients (bilateral in 1); 2) fenestration of VA in 1 patient; 3) anomalous posterior inferior cerebellar artery crossing the C1-2 joint in 1 patient; and 4) medial loop of VA in 5 patients. The anomalous vessel was dissected and the facet surfaces were drilled in all. The C-1 lateral mass screw was placed under vision, taking care not to compromise the anomalous vessel, although occipital screws or sublaminar wires were used in the initial cases. A medial loop of the VA necessitated placement of transpedicular or C-2 lateral mass screws instead of pars interarticularis screws. The anomalous vessel was injured in none. CONCLUSIONS Preoperative 3D CT angiography is a highly useful method of imaging the artery in patients with CVJ anomaly. It helps in identifying the anomalous VA or its branch and its relationship to the C1-2 facets. The normal side should be surgically treated and distracted first because this helps in opening the abnormal side, aiding in dissection. In the posterior approach the C-2 nerve root is always encountered before the anomalous vessel. The defined vascular anatomy helps in choosing the type of screw. The vessel should be mobilized so as to aid the drilling of facets and the placement of screws and spacers under vision, avoiding its injury (direct or indirect) or compression. With these steps, C1-2 (short segment) rigid fusion can be achieved despite the presence of anomalous VA.

‘Atlas shrugged’: congenital lateral angular irreducible atlantoaxial dislocation: a case series of complex variant and its management

PurposeThe commonly described congenital atlanto-axial dislocation and Basilar-Invagination is antero-posterior or rotational or vertical plane. However, congenital dislocation in lateral plane has received scant attention. The purpose of this manuscript is to describe this unusual entity and discuss its management.Materials and methodsThe clinic-radiological feature of seven patients with congenital lateral angular AAD (CLAAAD) were studied and managed. The unilateral C1 facet had subluxed lateral to C2–3 complex. The C1 and C2 facets were drilled comprehensively and repositioned with distraction, placement of metallic spacers and facet manipulation after insertion of screws. The post operative outcome was studied.ResultsThe presentation is usually with neck tilt (progressive in 3) and/or progressive spastic quadriparesis. The mean C1–2 tilt was 25.2°. C1 was bifid in six patients. C1 lateral mass was assimilated with occipital condyle on dislocated side in and the other side was normal (6 patients). The dislocated C1–2 joint was abnormally oblique as compared to contralateral side. The relationship of occiput and C1 was normal. Correction of dislocation and lateral tilt was achieved in all patients with subsequent correction of neck tilt and deficits. One patient required reoperation.ConclusionsThe acute angulation of joint on one side and near normal on other side leads to differential vertical movement, further accentuated by splaying of bifid C1. The entity is seen in young patients and often present with neck tilt and spastic quadriparesis. Management requires reshaping the joints and facet manipulation. If the reshaping is inappropriate, the joint is likely to redislocate before fusion occurs.

Olfactory region schwannoma: Excision with preservation of olfaction.

Olfactory region schwannomas are rare, but when they occur, they commonly arise from the meningeal branches of the trigeminal nerve and may present without involvement of the olfaction. A 24 year old lady presented with hemifacial paraesthesias. Radiology revealed a large olfactory region enhancing lesion. She was operated through a transbasal with olfactory preserving approach. This manuscript highlights the importance of olfactory preservation in such lesions.

Split cord malformation Type II with twin dorsal lipomas.

Although uncommon, variations in split cord malformation (SCM) have been described. However, a combination of SCM Type II and dorsal lipomas has not been reported. The authors describe the case of a 6-year-old girl who presented with a 1-year history of spastic paraparesis associated with a lipomatous swelling on her lower back. Radiology revealed a Type II SCM with a dorsal lipoma at that level. Intraoperatively, the authors observed a dorsal lipoma for each hemicord; these were excised, and the septum causing the split was cut. Premature separation of the cutaneous and neural ectoderm is predetermined for each neural fold, and a split at this level would give rise to SCM with twin dorsal lipomas, one for each hemicord.

Cerebello-pontine angle hemangiopericytoma: an orphan differential diagnosis.

There is a considerable overlap of clinical, radiological and athological features between meningioma, solitary fibrous tumor SFT) and hemangiopericytoma, however the different biological ehavior of hemangiopericytoma (HPC), in terms of high local ecurrence rate of 91% and 15 year risk of distant metastasis pproaching 70% makes the differentiation imperative [1]. HPCs orm less than 1% of intracranial tumors and are mainly supratentoial (62%) [1]. Such lesion in cerebellopontine angle (CPA) has been arely described making it an orphan diagnosis [1–7]. Preoperative adiological suspicion helps to plan total excision. Furthermore, istological diagnostic precision is essential to differentiate it from FT (common to this location) and meningioma where adjuvant adiotherapy is not required, unlike HPC [8]. We describe a case of PA hemangiopericytoma and review the literature.

Ependymoma misdiagnosed as tuberculoma, misguided by overemphasis on MR spectroscopy in endemic area

Ependymomas and tuberculomas are common paediatric posterior fossa lesions in developing countries and may be confused with each other due to some overlapping features. The distinction is important as the treatment for each is entirely different. We have described three young children in whom clinical–radiological features and the lipid peak seen on MR spectroscopy suggested the diagnosis of posterior fossa tuberculomas. All of them were started on empirical anti-tuberculosis therapy (ATT). Increase in size/no response to anti-tuberculosis therapy was disregarded as a paradoxical response. Finally, with clinical–radiological signs worsening, surgical excision was undertaken. Histopathology revealed ependymoma in all three children. This report highlights the overdiagnosis of tuberculosis in endemic areas due to biased clinical approach compounded by false positive investigations. Tissue diagnosis, though difficult by minimally invasive methods, should be sought before initiating ATT. The attempts to establish a tissue diagnosis should be continued even after starting empirical therapy, rather than waiting for the response.

Acute presentation of sagittal sinus thrombosis following closed head injury without overlying fracture

Dear Editor, Sagittal sinus thrombosis is rarely observed as a complication of closed head injury [1]. It is usually diagnosed or suspected in patients in whom fractures overly the sinus area or in patients who present late with features of raised intracranial pressure. As a rule dural sinus thrombosis following head injury follows subacute course [2]. Here we report a rare case of traumatic dural sinus thrombosis without overlying fracture with acute presentation. A 56 year old woman was admitted to our emergency department after road traffic accident. Immediately following injury her Glasgow coma score (GCS) was 15. Noncontrast computed tomogram (NCCT) of the head that was done within 2 h after injury showed small bifrontal hemorrhages without fracture (Fig. 1a–c). Her GCS progressively worsened to 9/15 from 15/15 in the next 6 h. Repeat NCCT (7 h after injury) revealed increase in the size of hemorrhages with mass effect (Fig. 1d–f). Patient underwent MRI brain with venogram. MR venography revealed superior sinus thrombosis of the anterior two-fifths (Fig. 1g). There was no co-morbid illness and she was not on any medications. Routine investigations were within normal limits. Platelet counts and coagulation profile were normal. She underwent bifrontal craniectomy with loose duraplasty with bone flap in abdomen (Fig. 1h, i). Post operatively, the patient was ventilated for 48 h and was given decongestants. She improved slowly over a period of 3–4 days. Low molecular weight heparin was instituted from the immediate post operative period and she was monitored regularly for development of new hemorrhages. Dural venous sinus thrombosis is occasionally seen following trauma. These are commonly associated with overlying skull fractures and have rarely been reported without fracture. Commonly, the sigmoid or transverse sinus is involved. Posttraumatic dural venous sinus thrombosis, especially those involving superior sagittal sinus, is rare and is associated with very high morbidity and mortality. Besides this, the presentation is usually subacute in this subset of patients [1, 3]. The index patient had acute presentation following post traumatic SSS thrombosis without overlying fracture, which is unique. The exact pathogenesis of sinus thrombosis following trauma is not clear. In patients with depressed or compound fractures, the direct injury to sinus may be responsible. Various proposed mechanisms of sinus thrombosis after minor head injury includes intramural hemorrhages caused by the rupture of small sinusoids, injury to endothelial lining, extension of the thrombus from injured emissary veins and compression of sinuses from intracranial edema. Furthermore abnormalities in clotting mechanism, alteration in the coagulation and disturbances in the blood flow may predispose to thrombosis [3, 4]. The mode of injury may determine the underlying cause of thrombosis. We speculate that sudden deceleration forces may lead to movements between mobile (veins) and fixed (sinus) parts giving rise to endothelial injury and thrombosis. The traumatic sinus thrombosis is suspected in patients with blunt head trauma who subsequently develop signs and symptoms (raised intracranial pressure or seizures or new deficits) that may indicate the development delayed traumatic dural venous sinus thrombosis or hemorrhagic venous infarction [2]. As a rule, DVST following head trauma follows a subacute course (few days to weeks). In our case the presentation was acute and patient deteriorated from conscious to an P. Salunke (*) : R. Garg : S. Futane Department of Neurosurgery, PGIMER, Sector 12, Chandigarh, India 1600l2 e-mail: drpravin_salunke@yahoo.co.uk

Posterior bilateral supernumerary atlantoaxial facets: true or false joint?

Study Design. Case report. Objective. To describe a symptomatic patient with bilateral posterior accessory C1–C2 joints and their differences from the true synovial joints. Summary of Background Data. Accessory joints between C1–C2 are rarely described. Origin and functional importance of such joints is unknown. Moreover only gross anatomic features of such joints were discussed in the past. The emphasis here is to review the morphology of such joints and to differentiate it from normal synovial joints. Methods. A 17-year-old male presented with progressive spastic ataxia precipitated by episodic transient quadriparesis secondary to trivial trauma. Radiology revealed bilateral posterior C1–C2 accessory joints compressing the cervicomedullary junction. Both C1–C2 posterior arches were removed, excising the accessory joints. Fusion was achieved using C1–C2 lateral mass screws and is doing well at follow-up. Results. The surfaces of these joints were smooth. Histopatholgy showed opposing osseous surfaces with articular cartilage but no synovium or articular capsule. Conclusion. Accessory C1–C2 joints are possibly a result of genetic aberration giving rise to abnormality in segmentation of C1 sclerotome. These joints are dysmorphic and partially formed as evidenced by the absence of synovial membrane and capsule. The function of such joints remains questionable. Level of Evidence: N/A

Complete segmentation failure causing non-dysjunction of os odontoideum and hypertrophic C1 arch: a case report.

A 40-year old woman presented with tightness and weakess in all limbs and urinary retention after sustaining trivial rauma. Her physical examination revealed spastic quadripareis with grade 2–3 power. She was dependant on others for her aily routine activities and required catheterization for urinary etention. Her radiographic findings at admission showed atlantoxial dislocation. X-ray CVJ showed hypertrophied arch of atlas ith atlanto-axial dislocation reducing partially on extension. CT VJ confirmed hypertrophied arch of atlas, with rudimentary os dontoideum fused to C1 anterior arch (Fig. 1). The transverse ligment was partially ossified. The atlanto-dental joint/space could ot be well appreciated. The lateral masses of C1 were well develped and C2 lateral masses were underdeveloped. The inferior C1

Klippel-Feil syndrome with atlanto-axial dislocation, anomalous vertebral artery, dextrocardia and situs inversus.

A 26-year-old male presented with progressive compressive yelopathy and left shoulder numbness since last 6 months. e had a short neck with restricted movements since birth, but as otherwise healthy and independent. His X-ray and computed omography (CT) of CVJ revealed central irreducible congenital tlantoaxial dislocation with atlanto-occipital assimilation and 2-3 fusion (Fig. 1A–D). MRI of CVJ showed cervicomedullary ompression with cervical cord syrinx (Fig. 1E). Chest X-ray and ltrasound of abdomen confirmed the clinical findings of dexrocardia and situs inversus (Fig. 1F). 3D CT angiography was erformed to evaluate the VA’s at CVJ. It showed small caliber ight vertebral artery with left persistent first intersegmental artery rossing across the C1-2 facets and joint space. This persistent first ntersegmental artery (left VA) also looped abnormally, initially