Controlling the structure of sequence-defined poly(phosphodiester)s for optimal MS/MS reading of digital information.

Digital polymers are monodisperse chains with a controlled sequence of co-monomers, defined as letters of an alphabet, and are used to store information at the molecular level. Reading such messages is hence a sequencing task that can be efficiently achieved by tandem mass spectrometry. To improve their readability, structure of sequence-controlled synthetic polymers can be optimized, based on considerations regarding their fragmentation behavior. This strategy is described here for poly(phosphodiester)s, which were synthesized as monodisperse chains with more than 100 units but exhibited extremely complex dissociation spectra. In these polymers, two repeating units that differ by a simple H/CH3 variation were defined as the 0 and 1 bit of the ASCII code and spaced by a phosphate moiety. They were readily ionized in negative ion mode electrospray but dissociated via cleavage at all phosphate bonds upon collisional activation. Although allowing a complete sequence coverage of digital poly(phosphodiester)s, this fragmentation behavior was not efficient for macromolecules with more than 50 co-monomers, and data interpretation was very tedious. The structure of these polymers was then modified by introducing alkoxyamine linkages at appropriate location throughout the chain. A first design consisted of placing these low dissociation energy bonds between each monomeric bit: while cleavage of this sole bond greatly simplified MS/MS spectra, efficient sequencing was limited to chains with up to about 50 units. In contrast, introduction of alkoxyamine bonds between each byte (i.e. a set of eight co-monomers) was a more successful strategy. Long messages (so far, up to 8 bytes) could be read in MS3 experiments, where single-byte containing fragments released during the first activation stage were further dissociated for sequencing. The whole sequence of such byte-truncated poly(phosphodiester)s could be easily re-constructed based on a mass tagging system which permits to determine the original location of each byte in the chain. Copyright © 2017 John Wiley & Sons, Ltd.

Surgical treatment of giant cell tumor of the cervicothoracic spine with combined anterior and posterior approaches.

Generally, giant cell tumors are rare and their localization in the spine is even more so. They are locally aggressive leading to spine instability and neurologic deficits. Radical excision is highly advocated. A role of radiotherapy in these tumors is controversial. We report the case of a giant cell tumor localized in D1 and D2 on a 39-year-old patient, presented with interscapular back pain, paraparesis grade 3/5 and sphincter dysfunction. Thoracic spine computed tomogarphy and magnetic resonance imaging showed a vertebral body tumor in D1 and D2, compressing the spinal cord at the same level. The patient initially underwent decompressive laminectomy of affected levels and stabilized with laminar hooks and rods. Second surgery performed through an anterior approach whereby tumor excision together with corpectomy of D1 and D2 carried out, autograft was placed and plate applied. Three weeks postoperatively, the patient's neurologic deficit recovered fully and back pain subsided.

Are infundibular dilatations at risk of further transformation? Ten-year progression of a prior documented infundibulum into a saccular aneurysm and rupture: Case report and a review of the literature.

Infundibular dilatations (IFDs) are conical, triangular, or funnel-shaped enlargements at the origin of cerebral arteries, and they are primarily located (7-25%) on the posterior communicating artery (PComA). Progression over time into a saccular aneurysm with a risk of rupture of a previously demonstrated IFD has rarely been reported. We report the case of a 60-year-old female who presented 10 years earlier with a subarachnoid hemorrhage caused by a left internal carotid artery aneurysm rupture. At that time, the carotid angiography showed the left internal carotid artery aneurysm and a right posterior communicating artery infundibular dilatation. Neck clipping for the left internal carotid artery aneurysm was performed and the patient was discharged with no neurological deficit. Ten years later, the patient suffered a second fatal subarachnoid hemorrhage; carotid angiography revealed a right posterior communicating artery aneurysm developed from the previously documented infundibular dilatation with a de novo right anterior choroidal artery aneurysm. This case is another proof of the small but growing number of examples of infundibular transformation over time, as well as their risk of progression into saccular aneurysms and subsequent rupture.

Unusual cause of non-discogenic sciatica: Foraminal lumbar root schwannoma.

BACKGROUND: Schwannomas are tumors of peripheral nerves that develop from the nerve sheath. Foraminal schwannomas are rare and account for 1-5% of all spinal schwannomas. The lumbosacral root schwannoma is a rare cause of sciatica and may raise confusion in diagnosis with late discovery of the tumor. CASE DESCRIPTION: We report the case of a patient 30 years of age with chronic left sciatica in whom lumbosacral magnetic resonance imaging (MRI) revealed a tumor involving the S1 nerve root. The excision of the tumor was simple. Histological examination revealed a benign schwannoma. The evolution was favorable postoperative with no neurological deficit, which confirms the good prognosis of this tumor. CONCLUSION: Nerve root schwannomas should be considered in the differential diagnosis of sciatica, especially when signs and symptoms of sciatica cannot be simply explained by prolapsed disc syndrome, which can often delay the diagnosis. Through this case presentation, the authors try to discuss the clinical and radiological features of this condition.

A rare case of adult medulloblastoma with spinal metastasis.

Medulloblastoma is a relatively common malignant brain tumor of childhood and relatively rare in adulthood, with a propensity for neuraxial spread via cerebrospinal fluid pathways. Osseous extraneural metastasis is uncommon and when it happens, radiologic findings are of sclerotic (60%), lytic (35%), and mixed patterns (5%) (Algra et al. (1992)). In this paper, we present a case of medulloblastoma metastiaszing to the lumbar spine and describe the magnetic resonance appearance, with emphasis on the image findings mimicking spondylodiscitis.

[Langerhans cell histiocytosis causing cervical myelopathy]. / Localisation cervicale d'une histiocytose langerhansienne responsable d'une compression médullaire lente.

Langerhans cell histiocytosis (LCH), a disorder of the phagocytic system, is a rare condition. Moreover, spinal involvement causing myelopathy is even rare and unusual. Here, we report a case of atypical LCH causing myelopathy, which was subsequently treated by corporectomy and fusion. An 8-year-old boy presented with 3 weeks of severe neck pain and limited neck movement accompanying upper and lower limbs motor weakness. CT scans revealed destruction of C5 body and magnetic resonance imaging showed a tumoral process at C5 with cord compression. Interbody fusion using anterior cervical plate packed by autologus iliac bone was performed. Pathological examination confirmed the diagnosis of LCH. After the surgery, the boy recovered from radiating pain and motor weakness of limbs. Despite the rarity of the LCH in the cervical spine, it is necessary to maintain our awareness of this condition. When neurologic deficits are present, operative treatment should be considered.

[Solitary intrasellar plasmocytoma revealed by a diplopia: a case report]. / Plasmocytome solitaire intrasellaire révélé par une diplopie : à propos d'un cas.

INTRODUCTION: Plasmocytomas rarely invade the skull base. It can be solitary or multiple. The clinical presentation mainly consists in a progressive neuropathy involving many cranial nerves, or may simply present as an optochiasmatic syndrome. OBSERVATION: The authors report a case of a female patient aged 68 years presenting with an optochiasmatic syndrome with an anosmia and paralysis of the right sixth (VI) cranial nerve progressing over two years prior to her hospitalisation. Cerebral MRI showed a voluminous intrasellar lesion, isointense on T1 and hyperintense on T2, enhancing intensely after gadolinium injection with evidence of invasion of the sphenoid and cavernous sinuses. The endocrinologic assay was normal. A sphenoidal biopsy by the rhinoseptal route permitted the diagnosis of a plasmocytoma. A complete radiologic and laboratory assessment of the patient was accomplished, the patient benefited from local radiotherapy. DISCUSSION: Plasmocytomas are malignant tumors that are essentially osseous. The cervicocephalic region is rarely afflicted (1%). Extension to the cranial base seldom occurs. Less than 30 cases have been described in the literature simulating the other numerous neoplastic intrasellar lesions. CONCLUSION: Plasmocytomas of the cranial base revealing a myeloma represent a very rare entity. Nevertheless, whether solitary or multiple, a plasmocytoma must be considered amongst the differential diagnoses in the face of any invasive lesion of the sphenoid sinus.

[Adult spinal cord injury with no radiographic bone lesion: analysis of nine consecutive patients]. / Atteinte médullaire cervicale post-traumatique sans lésion osseuse du rachis chez l'adulte: analyse de neuf cas consécutifs.

BACKGROUND: Spinal cord injury with no radiographic bone lesion described as spinal cord injury without radiographic abnormality (SCIWORA) in childhood is less often reported in adults than in children. This study was undertaken to report our experience in the management of nine cases over 25 years. PATIENTS AND METHODS: This was a retrospective study from 1985 to 2009 concerning nine adult patients who sustained spinal cord injury with no radiographic abnormality. The ratio among all cervical spine traumas for the same period was 2.21%. Magnetic resonance imaging (MRI) was performed in all the patients. The patients' clinical status at the time of admission and discharge was evaluated using the Frankel's grading system. We report the results based on the clinical, epidemiologic and radiological findings and outcomes. RESULTS: The mean age of our population was 37.43 years, ranging from 18 to 60 years. All the patients were men. The main etiology was falls (5/9) followed by road traffic accidents (4/9). According to the Frankel's grading system, four patients (44.45%) were grade A, four were grade B (44.45%), and one was grade C (11.11%). On MRI, medullar lesions were: contusion, non-compressive cervical disc herniation, cervical spine stenosis, and two cases of normal cervical spine. Four patients were operated on via the posterior cervical spine approach (laminectomy, C3-C7 in three cases and C1-C3 in one case). The other five patients were treated orthopaedically for 6 to 8 weeks. Three patients (3/9), who were Frankel's grade B and C with no demonstrable injury on MRI, improved to Frankel a useful neurological grade (Frankel's grades D or E) at the time of discharge. One patient evaluated as Frankel's grade A died from cardiovascular disturbance. CONCLUSION: Spinal cord injury with no radiographic abnormality accounted for 2.21% of cases of spinal cord injury in our series. MRI is the investigation of choice, having diagnostic and prognostic value because it demonstrates neural and extraneural injuries and helps to identify surgically correctable abnormalities.

Intracranial meningioma in children: different from adult forms? A series of 21 cases.

OBJECTIVE: Intracranial meningiomas are very rare in children, comprising only 0.4 to 4.1% of pediatric tumors and only 1.5 to 1.8% to all intracranial meningiomas. The goal of this study of pediatric meningiomas was to establish their epidemiological profile as well as their clinical and radiological features, to assess the long-term outcome, and compare this result with adult meningioma. PATIENT AND METHODS: We conducted a retrospective study from June 1983 to June 2007; during this period 521 patients underwent surgery for primary meningioma at the Rabat Hospital, Department of Neurosurgery. Twenty-one patients were under 16 years of age (4%). The clinical charts and imaging data were reviewed. RESULTS: The mean age was 10.3 years (range: 2 to 16 years), with 13 boys and eight girls. In one patient a neurofibromatosis was associated. The mean delay to diagnosis was 4.6 months (range: 1 to 12 months). The most common clinical sign was raised intracranial pressure (90%). Of the meningiomas diagnosed, 47% were convexity meningiomas while 24% were parasagittal and 19% were skull-base meningiomas; in two cases (9.5%) the location was intraventricular. The mean tumor diameter was 6.6 cm (range: 3 to 10 cm). A large cystic component was found in 24% of the cases. Surgery achieved a Simpson grade I resection in 47%; 62% of the tumors were grade I and 24% were grade II based on World Health Organization pathological classification. The mean follow-up period was 33 months (range: 6 to 120 months). The recurrence rate was 33%. CONCLUSION: Pediatric meningiomas are larger than those found in the adult population; there is a male predominance with high incidence of a cystic component and high-grade meningiomas, thus explaining the increased recurrence rate despite the multimodal treatment.

[A case of cystic craniofacial fibrous dysplasia]. / Un cas de dysplasie fibreuse kystique craniofaciale.

INTRODUCTION: Fibrous dysplasia is a benign, idiopathic, fibro-osseous disease. CLINICAL CASE: A 17-year-old girl had presented with left proptosis for the previous two years, associated to homolateral hemicranial pain. Clinical examination was normal except for non-reducible axile exophthalmia. Computed tomography and magnetic resonance imaging of the head revealed an extensive cystic tumor of the left fronto-ethmoido-sphenoidal region, with compression of the left frontal lobe and medial orbital wall. The radiological appearance suggested a mucocele but histological examination, after surgery, proved a fibrous dysplasia. DISCUSSION: Fibrous dysplasia with fronto-sphenoido-ethmoidal localization may be misdiagnosed as mucocele. Histology proves the diagnosis.

[Orbital tumors. Neurosurgical activity]. / Tumeurs orbitaires. Activité neurochirurgicale.

In this chapter, we report the results of orbital tumor management in a few neurosurgical departments and compare it to a Paris neurosurgical department that has developed a close relation with an ophthalmological department. These departments' activity is quite low, treating mainly sphenoorbital meningiomas. Other tumor groups are unequally and sporadically managed.

[Posterior fossa extradural and extracranial hydatid cyst]. / Kyste hydatique intra- et extracrânien de la fosse cérébrale postérieure (à propos d'un cas).

Hydatidosis is an endemic disease in Morocco. Cerebral echinococcosis is a relatively rare entity accounting for only 1-2% of all hydatid cysts in humans. Extradural hydatid cyst of the posterior fossa is a very uncommon site for the disease: only four cases have been reported in the literature. We report the case of a 37-year-old admitted for high intracranial pressure. Brain MRI showed an extradural and extracranial posterior fossa cyst without enhancement after contrast medium injection. Multiple hydatid cysts were removed and the histological examination of the tissue sample confirmed the diagnosis. The patient was given albendazole postoperatively with good follow-up 6 months later.

Magnetic resonance imaging for spinal cord tumors. A report of twenty cases.

This paper discusses spinal cord tumors including imaging characteristics with emphasis on magnetic resonance imaging and advances in treatment. This is a retrospective study of 20 cases patients with neoplasms arising from the spinal cord. All of our cases were explored by magnetic resonance imaging (1.5T) using T1-weighted imaging (Spin Echo), T2-weighted imaging (Spin Echo) and T1-weighted imaging with Gadolinium administration. Pain is the earliest symptom, characteristically occurring at night when the patient is supine. Ependymoma were observed in 11 cases. Astrocytoma was noted in five cases. Other uncommon tumors were identified in four cases: oligodendroglioma (n=1), epidermoid cyst (n=1), hemangioblastoma and metastasis (n=1). In MRI most tumors are isointense or slightly hypointense compared to the normal cord signal with homogenous or irregular enhancement. We describe the characteristic magnetic resonance findings and differential diagnosis of spinal cord tumors. Spinal cord lesions comprise approximately 2-4% of all central nervous system neoplasms. Magnetic resonance imaging plays a central role in the imaging of spinal cord neoplasms.

Sphenoid sinus aspergillosis simulating pituitary tumor in immunocompetent patient.

Aspergillosis of the sphenoid sinus is rare in immunocompetent patients. It may be mistaken for a sellar region tumor. A 65-year-old, human immunodeficiency virus-negative man presented with a 3-week history of cranial nerve III paresis and visual deterioration. The patient had a long-term history of tobacco snuff abuse. CT scans and MRI demonstrated a space-occupying lesion of the sellar and sphenoid sinus region. Presumptive diagnosis of pituitary macroadenoma was made and the patient was operated on via a transnasal-transsphenoidal approach. After the sphenoid sinus was opened, a yellow-brownish gluey material with crumbly debris extruded and was aspirated. The dura was intact. Histopathology revealed numerous Aspergillus hyphae without tissue invasion. Postoperatively, the cranial nerve III paresis resolved in a few days and visual acuity improved. Sphenoid sinus aspergillosis should be included in the differential diagnosis of sellar region processes, even in immunocompetent patients. Early diagnosis and transsphenoidal removal provides good results without the need for systemic antifungal therapy in non-invasive aspergillosis.

[Os odontoideum: clinical and radiological aspects]. / Os odontoïdeum : aspects cliniques et radiologiques.

Few reports of os odontoideum have been made. We report two cases where this affection was revealed by cervical pain and hemiparesis in one case and acute tetraparesis in the other. Patients with os odontoideum usually present with neurological signs, but some have only cervical pain and some others remain asymptomatic. Radiological exams, including radiograms, cervical scanner and MRI lead to the diagnosis. Different surgical treatment can be proposed to symptomatic patients. Prophylactic surgical treatment is not indicated.

[Paraganglioma of the latero-sellar area. Case report]. / Paragangliome latéro-sellaire. A propos d'un cas.

Paraganglioma of the sellar and latero-sellar area is extremely rare. We report a case of latero-sellar and suprasellar paraganglioma of a 58-year-old women which caused deterioration of visual acuity and left exophthalmia without endocrine dysfunction. Magnetic resonance imaging showed a large tumor in the sellar and parasellar area, which extended to the left cavernous sinus and infiltrated the left orbit, the ethmoid, the sphenoidal sinus and the left pterygomaxillary fossa. Surgery by transcranial, left frontotemporal approach, enabled subtotal removal. Definitive histologic examination revealed a paraganglioma with signs of anaplasis. We report our clinical findings and present a review of literature.

Cerebellous metastases in patients with uterine cervical cancer. Two cases reports and review of the literature.

Brain metastases from cervical cancer are extremely rare. We report on two patients who developed cerebellous metastases following uterine cervical cancer. The interval between diagnosis of the primary cancer and diagnosis of brain metastasis was 8 months. The main complaint was symptoms of increased intracranial pressure and cerebellous syndrome. Surgical excision of the brain lesion followed by radiation therapy was performed in the first case. The second patient received palliative radiation therapy. The first patient died 8 months after diagnosis. The second patient is alive 2 months after diagnosis.

[Primary intradural extramedullary hydatidosis. Case report and review of the literature]. / L'hydatidose intradurale extramédullaire primitive. A propos d'un cas and revue de la littérature.

The authors report a case of cauda equina compression by intradural hydatid cyst. An 18-year-old man presented with paraparesis and sphincter dysfunction. MRI showed an intradural cystic lesion extending from L1 to L2 with low signal intensity on T1 and high signal intensity on T2. The cyst was removed after laminectomy and opening of the dural sac. Histological and parasitic examinations confirmed a diagnosis of hydatid cyst. The patient improved progressively after surgery. The similar 22 cases of intradural extramedullary hydatid disease reported in the literature were reviewed. All spinal areas were involved, with a predilection for the thoracic region. Neurological complications were usual with rapid spinal cord compression in this rare form of hydatid disease. The treatment was by surgery with a favourable outcome compared to the classic hydatid cyst of the spine.

[Orbital lymphangioma. A case report]. / Lymphangiome orbitaire. A propos d'un cas.

The diffuse form of orbital lymphangioma is well known for its difficult surgical treatment. A diffuse orbital lymphangioma was diagnosed in a 6-year-old girl, revealed by unilateral recurrent proptosis. The imaging procedure discovered a mass presumed to be vascular in nature. The initial incompleted surgical removal was followed by 3 recurrences motivating 3 reoperations. Finally, the tumor was removed incompletely, with an acceptable reduction of the proptosis. The pathologic analyses indicated lymphangioma. Some vascular orbital tumors such as lymphangioma, may be very difficult to manage because of local spreading and frequent recurrence.

Pattern of cerebral aneurysms in Morocco: review of the concept of their rarity in developing countries: report of 200 cases.

OBJECTIVE: Many neurosurgeons consider cerebral aneurysms to be rare in Africa and the Middle East. In this report, we describe the pattern of cerebral aneurysms in Morocco and call into question the idea of their rarity in developing countries. Our objective is to urge neurosurgeons in these areas to track them and to treat them under better conditions. METHODS: We report a retrospective study of 200 patients with cerebral aneurysms admitted to our department between 1983 and 1999. The results of this study are supported by pertinent epidemiological surveys, anatomic studies on the incidence of cerebral aneurysms in Morocco, and analysis of the literature related to the epidemiology of aneurysms in developing countries. RESULTS: The patients in our series ranged in age from 7 to 70 years (mean age, 52 yr), with a slight female predominance (52%). They presented with subarachnoid hemorrhage (173 patients), cranial nerve palsy (18 patients), or mass symptoms (9 patients). The delay between subarachnoid hemorrhage and admission ranged from 1 to 30 days (mean, 14 d). The aneurysm was located in the internal carotid artery in 42%, in the anterior communicating and anterior cerebral arteries in 28%, in the middle cerebral artery in 19%, and in the vertebrobasilar artery in 10%. Multiple aneurysms were encountered in 9% and giant aneurysms in 15.5%. Seventeen patients died before surgery (with vasospasm in 13 cases and rebleeding in 4 cases), and 19 died after surgery. Follow-up, ranging between 1 and 10 years, revealed good outcomes with complete recovery in 64.5% and recovery with major sequelae in 7%. Pre- and postoperative mortality represented 18%; there was no operative treatment and no follow-up in 11.5%. CONCLUSION: Some data in this study (the delay between subarachnoid hemorrhage and admission, the high incidence of urban patients [80%], and the high rate of giant aneurysms) explain why many cases of ruptured aneurysms are not diagnosed. The analysis of our clinical series and the results of the epidemiological surveys show that the incidence has doubled every 5 years. These findings confirm that cerebral aneurysms are not rare in Morocco. A critical reading of the published articles claiming a low incidence of cerebral aneurysms in Africa, the Middle East, and Asia shows that this conclusion is not based on accurate and reliable statistical studies. Neurosurgeons in these regions should abandon this idea of rarity, and they should search for arterial cerebral aneurysms and develop the optimum conditions for the treatment of patients with aneurysms.