Transient bilateral Basal Ganglia lesions in rotavirus encephalopathy. A case report.

Rotavirus gastroenteritis may be associated with the onset of an acute reversible encephalitis. We describe a case of transient bilateral basal ganglia lesions after a prodromal gastroenteritis which completely resolved four months later. Diffusion weighted images were determinant to depict the basal ganglia abnormalities and were helpful to evaluate the prognosis. A review of the literature indicates that many diseases may be accompanied by signal abnormalities within the basal ganglia and that differential diagnosis is possible only through the simultaneous evaluation of imaging, clinical and laboratory findings.

Neuropathic pain in temporomandibular joint disorders: case-control analysis by MR imaging.

BACKGROUND AND PURPOSE: Temporomandibular joint disorders (TMJ-D) may be associated with the onset of neuropathic pain. The purpose of this study was to prospectively assess if, at the open-mouth position, the distance between the temporomandibular joint (TMJ) disk and the mandibular nerve is shorter in patients with TMJ-D and neuropathic pain vs patients with TMJ-D without neuropathic pain or in healthy people. MATERIALS AND METHODS: After ethical committee approval, we evaluated by MR imaging 16 TMJs with TMJ-D and neuropathic pain, 16 TMJs with TMJ-D without neuropathic pain, and 16 TMJs of healthy volunteers. All of the subjects were informed about the study procedure. We evaluated the distance between the TMJ disk and the mandibular nerve at the oval foramen level. Furthermore, the presence within the TMJs of internal derangement, osteoarthrosis, joint effusion, and bone marrow edema was evaluated. RESULTS: At the maximal open-mouth position, the distance between the TMJ disk and the mandibular nerve is shorter in patients with TMJ-D and neuropathic pain than in patients with TMJ-D without neuropathic pain or in healthy volunteers (P < .05). The imaging findings of TMJ internal derangement, effusion, osteoarthrosis, and bone marrow edema were present both in patients with TMJ-D without neuropathic pain and in patients with TMJ-D and neuropathic pain. CONCLUSIONS: We suggest that a closer proximity between the TMJ disk and the mandibular nerve could be one of the causes of the onset of neuropathic pain in patients with TMJ-D and neuropathic pain.

Morphometric evaluation of the temporomandibular joint and the masticatory spaces: the role of high-definition MRI.

AIM: The aim of this work was to describe the anatomy of the temporomandibular joint (TMJ), the masticator spaces and their possible variance by means of magnetic resonance imaging MRI. METHODS: We evaluated one TMJ in each of 28 volunteers (14 males and 14 females) without temporomandibular disorders. The TMJ with mouth closed was evaluated on axial, coronal and sagittal planes obtained with a 1.5 Tesla magnetic resonance scanner. MRI scans of the anatomic patterns of the temporomandibular region were analyzed and compared with the classical anatomy notions reported in the literature. Morphometric evaluation of the temporomandibular region and the medial and lateral pterygoid muscles was carried out. RESULTS: MRI anatomy of the TMJ, the masticator spaces and their possible variance were accurately described. In addition, morphometric evaluation of the TMJ and the masticator spaces was performed. Statistical analysis of the measurements showed that the length of the structures related to the glenoid fossa were usually longer in the female than in the males, whereas the condyle and masticator muscles were usually greater in the males than in the females. T-tests showed no significant differences (P > 0.05) between the measurements of the right and left TMJ. CONCLUSIONS: In preoperative maxillofacial surgery assessment, MRI is a useful tool to reduce operating time, avert surgical complications and improve patient outcome.

An interpretation of optic nerve tortuosity. A case report.

Magnetic resonance imaging disclosed both optic nerve tortuosity and kinking in a 64-year-old man with orbital pain and monolateral abducens nerve palsy. The association between optic nerve tortuosity and abducens nerve palsy is often described in literature reports of idiopathic intracranial hypertension. However the diagnosis of idiopathic intracranial hypertension was excluded in our patient because of the absence of other signs such as papilledema (universally present in the cases of idiopathic intracranial hypertension), visual loss, headache and flattening of the posterior sclera. Other possible diagnoses to be considered when looking at a case of optic nerve tortuosity are neurofibromatosis and/or optic nerve glioma. Tortuosity of both optic nerves seems to be isolated in our patient and not associated with other diseases or disorders. We suggest that in some patients optic nerve tortuosity could be correlated with an aberrant anatomical development of the optic nerve. Further studies are necessary to confirm this hypothesis which currently remains conjectural.

Osteoblastoma of the orbit. A case report and review of the literature.

We describe a case of benign orbital tumour involving the frontal sinus and ethmoidal cells. CT findings were typical of "bone tumour of the orbit", histological analysis yielded a diagnosis of benign osteoblastoma. A review of the literature disclosed only 13 well documented cases. We compared out radiological findings with the features described in these reports. CT patterns were similar in most cases. The lesion generally appears as a heterogeneous mass where it is possible to appreciate both high density portions and low density areas. On MRI osteoblastoma shows an iso- low signal both in T1 and in T2 sequences. Less frequently the lesion may yield a high signal in T2 images. The orbit is rarely involved by bone tumours, but all bone tumours may theoretically involve the orbit, often making it difficult to establish the right differential diagnosis by imaging. Thirteen cases are insufficient to describe general radiological criteria to improve the specificity in detection of this disease and a broader outlook is essential. For this reason we also examined the radiological signs of bone tumours involving other portions of the body. Even though many literature reports suggest CT is the landmark in bone tumour diagnosis, we think it should always be accompanied by MRI. MRI is known to overestimate local staging, but its contribution to differential diagnosis among various tumours may be decisive.

Imaging of Rathke's Cleft Cysts: Criteria for a Differential Diagnosis.

Rathke's cleft cysts are a congenital disorder of the pituitary gland and derive from abnormalities of the development of the adenohypophisis. The variability of the MRI signal of Rathke's cleft cyst hampers the differential diagnosis with the other cystic lesions of the pituitary gland. Nevertheless a comparison between the various findings reported from by author we reviewed indicates that a description of useful criteria for a differential diagnosis is possible. We suggest that the mean age at onset, the symptoms, the magnetic signal intensity, the location within the gland, the relations with the surrounding structures and the behaviour after contrast injection should always be considered in the diagnostic work-up of Rathke 's cleft cysts. There is no consensus in the literature on the correct therapeutic protocol. We suggest following up a small asymptomatic Rathke's cleft cyst (except mucoid cysts) because they do not generally enlarge. Surgery is instead the gold standard for symptomatic Rathke's cleft cysts, large Rathke's cleft cysts and mucoid Rathke's cleft cysts. Mucoid Rathke's cleft cysts, even when small, may cause an intense pituitary inflammation which could lead to irreversible endocrine dysfunction.

Hemifacial Spasms and Involuntary Facial Movements. Role of Magnetic Resonance in the Diagnostic Work-up. A Case Report.

Caution is required when dealing with patients presenting hemifacial spasm as the symptom is common to many disorders (tumours, herpes zoster, a frigore paralysis, neurovascular conflict…). Often no reasonable cause of the spasm is found, but treatment must be attempted because hemifacial spasm can be highly debilitating. We describe a case of hemifacial spasm, initially deemed idiopathic, in which MRI demonstrated neurovascular conflict as the cause. It is not always easy to find a clear MRI pattern, but if the scan identifies the tortuousness of the arteries in the vicinity of the VII nerve root exit, it is highly probable that this is the true cause of hemifacial spasm. Even when it is not possible to identify this pattern, neurovascular compression cannot be ruled out. The good results of microvascular decompression in patients without a typical MRI pattern suggest that MRI is specific, but not always sensitive. There is no consensus in the literature on the sensitivity of MRI in the detection of neurovascular compression and values vary widely. It is generally believed that experience and different performance of the MR systems strongly influence the diagnosis of neurovascular conflict.

Carotid body paraganglioma. Diagnosis and treatment by angiography.

Paraganglioma is a rare neoplasia of neural crest origin. It most commonly arises in carotid body, jugular bulb, tympanic plexus on the promontory, and along the vagal nerve pathway or anywhere along the paraganglia pathway. This review describes our experience of cervical paraganglioma. Although there is no consensus in the literature on preoperative angiographic embolization, we think angiography is the gold standard in the diagnosis and treatment of paraganglioma. A small paraganglioma probably does not usually require preoperative embolization because the risks may exceed the benefits. But angiography is mandatory in the diagnosis and treatment of large highly vascular paragangliomas. Imaging of the vascular map of the tumor, that is only possible by angiography, will help the neurosurgeon evaluate the real extension of the neoplasia and chose treatment modalities. Embolization is performed to decrease operative bleeding, shorten the surgery timing and avoid cranial nerve deficit. Cemal Umit Isik et al. studied four brothers with familial paragangliomas noting unexplained concomitant thyroid functional disorders in their patients. Because of the pedigree they thought this may have been a coincidence. Our reported case, unrelated to the Turkish family, also had hypothyroidism suggesting that the relation between paraganglioma and thyroid dysfunction may not be merely a coincidence.