Jean-Pierre Guichard

Sinking Skin Flap Syndrome and Paradoxical Herniation After Hemicraniectomy for Malignant Hemispheric Infarction

Background and Purpose— “Sinking skin flap” (SSF) syndrome is a rare complication after large craniectomy that may progress to “paradoxical” herniation as a consequence of atmospheric pressure exceeding intracranial pressure. The prevalence and characteristics of SSF syndrome after hemicraniectomy for malignant infarction of the middle cerebral artery are not well known. Methods— We analyzed a prospective cohort of 27 patients who underwent hemicraniectomy for malignant middle cerebral artery infarction. All had a clinical and brain imaging follow-up at 3 months and were followed until cranioplasty. Results— Three of 27 patients (11%) had, at 3 to 5 months posthemicraniectomy, SSF syndrome with severe orthostatic headache as the main symptom. In addition, 4 patients (15%) had radiological SSF syndrome but no clinical symptoms except partial seizures in one. Patients with SSF syndrome had a smaller surface of craniectomy (76.2 cm2 versus 88.7 cm2, P=0.05) and a tendency toward larger infarct volume, an older age, and a longer delay to cranioplasty than those without this syndrome. Conclusions— SSF syndrome either clinically symptomatic or asymptomatic affects one fourth of patients 3 to 5 months after hemicraniectomy for malignant middle cerebral artery infarction. It should be diagnosed as early as possible to avoid progression to a paradoxical herniation.

Mucocele of the Sphenoid Sinus: A Late Complication of Transsphenoidal Pituitary Surgery

In an 18-month period, 3 cases of sphenoidal mucocele following pituitary surgery were diagnosed at our institution. Only 1 case of this late-onset disorder has yet been reported as a pitfall of the transsphenoidal route. Symptoms include recurrent headache and visual complications. Diagnosis was delayed because of misinterpretation of the magnetic resonance imaging findings, which actually showed the development of a sphenoid mucocele long before clinical symptoms occurred. These 3 cases suggest that attention should be focused not only on the sella turcica, but also on the sphenoid sinus, in analyzing the magnetic resonance imaging data. The treatment consists of endoscopic transnasal marsupialization, since the mucocele is lined by normal epithelium with an inflammatory reaction that will heal with drainage. At the time of surgery, prevention would require either endoscopic control of the mucosal remnants, in case of sinus exclusion, or leaving the sphenoid sinus air-filled under a sealed sella.

Intrasphenoidal transsellar encephalocele repaired by endoscopic approach.

Spontaneous sphenoidal encephaloceles are rare entities. In the case of intrasphenoidal encephaloceles, most defects are temporosphenoidal and occur in the lateral wall of the sphenoidal sinus. There have been to our knowledge only 7 reports of medial, transsellar encephaloceles in the literature. We report a case of intrasphenoidal transsellar encephalocele that was successfully managed through an endoscopic approach with complementary lumboperitoneal shunting. This disorder presents a challenge in surgical management because of the involvement of opticochiasmatic structures, the hypothalamopituitary axis, and the delicate vasculature of the circle of Willis in and around the encephalocele, besides proximity to the cavernous sinus. Rhinologists should be aware of these malformations, since the optic nerve or chiasma may be totally exposed in the sphenoidal sinus in the course of this disease. This case illustrates the need for magnetic resonance imaging in case of sphenoidal abnormalities, as well as the possibility of endonasal repair without a transcranial approach for large intrasphenoidal encephaloceles.

A Delayed Teflonoma of the Neck Simulating a Thyroid Neoplasm

Pseudotumoral granulomatous foreign body reaction to Teflon particles is a rare complication of intracordal Teflon paste injection for unilateral vocal cord paralysis. We report a case of pseudotumor of the thyroid area, which appeared 3 years after intracordal Teflon paste injection and presented as a cold thyroid nodule. At frozen section examination the presence of a giant-cell foreign body granuloma containing numerous refringent particles suggested a teflonoma. The diagnosis was confirmed on permanent sections, after comparison of the intratissular particles with fresh Teflon paste, under conventional and polarized light. The histological and ultrastructural features of the lesion are presented and attention is drawn to the long delay between initial Teflon injection and the clinical manifestation of the lesion.

Radionecrosis of the frontal lobe as a consequence of malignant ethmoid tumor management: incidence, diagnosis, risk factors, prevention and management

Malignant ethmoid tumors are treated by surgery followed by radiotherapy. This study aimed to evaluate the incidence, risk factors and outcome of radionecrosis of frontal lobe and determine preventive measures. Retrospective study of ethmoid malignancies treated from 2000 to 2011. All patients underwent surgery with/without anterior skull base resection using endoscopic or external approaches followed by irradiation (mean dose 64xa0Gy). Median follow-up was 50xa0months. Eight of 50 patients (16xa0%) presented with fronto-basal radionecrosis, connected to duraplasty, with a latent interval of 18.5xa0months. Although asymptomatic in six, radionecrosis triggered seizures and required surgery in two cases. Survival was not impacted. Risk factors included dyslipidemia, occurrence of epilepsy and dural resection. Radionecrosis may result from the combination of anterior skull base resection and radiotherapy for the treatment of ethmoid malignancies. Preventive measures rely on improving the duraplasty and optimization of the Gy-dose delivery.

Saccular measurements in routine MRI can predict hydrops in Menière’s disease

Most patients with suspicion of hydrops do not have access to MRI with 3D reconstruction of the endolymphatic space. Our main objective was to show that measurements of the saccule on a non-enhanced 3D-T2 MRI could show hydrops and help diagnose Menière disease. We conducted a prospective study from 2015 to 2016 to compare consecutive patients consulting for Menière’s disease to a control group (patients with unilateral non-hydrops disorders and contralateral healthy ears). They all received full auditory and vestibular testing. They also underwent a 3-Tesla 3D-T2 MRI using CISS sequence (0.4xa0mm thick slices), which were blindly evaluated by two independent neuroradiologists. The saccular height and width were measured in a coronal plane and Menière’s disease patients’ symptomatic ears were compared to asymptomatic and control ears. 36 patients with definite Menière’s disease and 36 control patients were studied, including 42 symptomatic Menière, 30 asymptomatic Menière and 72 control ears. Saccular measurements were significantly different between symptomatic Menière ears compared to healthy ears (1.59 vs 1.32xa0mm, pxa0<xa00.001 for height; 1.13 vs 0.90xa0mm, pxa0<xa00.001 for width). Symptomatic and asymptomatic Menière ears’ measurements were not significantly different (pxa0=xa00.307 and pxa0=xa00.109). Using ROC curve, we found cut-off values for saccular height 1.51xa0mm, Sexa0=xa063%, Spxa0=xa095% and width 1.05xa0mm, Sexa0=xa041%, Spxa0=xa095%. Routine 3D-T2 MRI, which patients must undergo for differential diagnosis, could help diagnose hydrops with high specificity using saccular measurements.

Cas cliniqueAssociation d’un kyste arachnoïdien et d’une hétérotopie de tissu glial dans le méat auditif interneAssociation of an arachnoid cyst with heterotopic neuroglial tissue in the internal auditory canal

OBJECTIVESnWe report a case of an association of an arachnoid cyst with heterotopic neuroglial tissue in the internal auditory canal.nnnMATERIAL AND METHODSnA 66-year-old woman consulted for cochleovestibular syndrome.nnnRESULTSnMRI demonstrated a lesion with spontaneous hypersignal on T1- and T2-weighted images, instigating surgical exploration. We discovered a hematic arachnoid cyst associated with heterotopic neuroglial tissue arising in the internal auditory canal.nnnCONCLUSIONnAn arachnoid cyst arising within the cerebellopontine angle or the internal auditory canal is a rare occurrence. Clinical manifestations are identical with those produced by a cochleovestibular schwannoma. MRI usually demonstrates a nonenhancing isointense cystic mass with cerebrospinal fluid on all sequences (hypointense on T1-weighted and hyperintense on T2-weighted images). These lesions are usually monitored. Spontaneous hypersignal on T1- and T2-weighted images makes diagnosis difficult, as in our case, leading to surgical exploration.

Author’s reply to “Letter to the editor on the article: Saccular measurements in routine MRI can predict hydrops in Menière’s disease by Simon F et al.”

This is an answer to the Letter to the Editor regarding our previously published article « Saccular measurements in routine MRI can predict hydrops in Menière’s disease ». We thank the authors for their interest in our article and their insightful comments. We would like to emphasise that our article was a preliminary study and to our knowledge the first published series establishing a correlation between measurements of saccular morphology in T2-weighed 3D CISS images and clinical definite Menière’s disease. Therefore, we agree with the authors of the Letter that verifying reproducibility is paramount for the technique to be widely used. Further studies should be conducted to investigate the risk of artefacts reducing the reliability of saccular width measurements and to confirm the clinical implications. We recommend the use of saccular height measurements which have higher reliability. Also, the goal of the study was to present a possible radiological alternative to the more established methods of endolymphatic hydrops visualisation. If accessible, we agree that the latter techniques should be preferred, but we find that they are unfortunately too often unavailable in routine clinical practice to ENT physicians.

Petrous and sphenoid arachnoid cysts: Diagnosis and management

Intraosseous arachnoid cysts are rare and difficult to diagnose. The purpose of this study was to describe the clinical and radiological semiology of petrous and sphenoid arachnoid cysts and to propose a specific management strategy.

Detection of Residual Disease with CT Scan after Surgery of Juvenile Nasopharyngeal Angiofibroma

Abstract Objectives: High recurrence rates have been reported for juvenile nasopharyngeal angiofibroma (JNA) involving the skull base. Early diagnosis and treatment of residual disease (RD) is a main determinant to prevent regrowth of the tumor. The purpose of this retrospective study was to evaluate the diagnostic accuracy of contrast-enhanced CT scan for the detection of RD in the early postoperative course after surgical excision of JNA. Methods: Based on an inception cohort of 20 boys who had a contrast-enhanced helical CT scan in the days following an apparently complete surgical excision of JNA with initial expansion in the skull base with a minimum of 2 years of follow-up, 4 independent, blinded readers evaluated the occurrence of RD. Final diagnoses were rendered based on results of histologic examination of excised specimens of RD or clinical and radiologic follow-up. The Cohen k test was performed to examine interreader agreement. Results: Postoperative contrast-enhanced CT scan had a sensitivity of 74%, a specificity of 98%, a positive predictive value of 97% and a negative predictive value of 82% for detection of RD. The prevalence of RD was 45%. Interreader agreement was high for detection of putative RD (k= 0.83). Conclusion: Contrast-enhanced helical CT scan performed in the days following surgical excision of JNA is an accurate tool to evaluate excision of JNA and to perform an additional endoscopic procedure if needed. Results of further studies are necessary to prove whether early postoperative contrast CT affects the optimal therapeutic management and high recurrence rate of JNA involving the skull base.