MRI of cranial nerve enhancement

Orbital apex syndrome due to trigeminal perineural spread of sinonasal leprosy: a case report

Leprosy is a granulomatous disease primarily affecting the skin and peripheral nerves caused by Mycobacterium leprae, but also significantly involving sinonasal cavities and cranial nerves. It continues to be a significant public health problem, and despite multidrug therapy, it can still cause significant morbidity. The awareness of cranial nerve, intracranial and orbital apex involvement as in our case is important for appropriate treatment measures.

Diffusion MR imaging of postoperative bilateral acute ischemic optic neuropathy

A 57-year-old woman experienced bilateral acute ischemic optic neuropathy after spine surgery. Routine MR imaging sequence, T2-weighted image, showed subtle high signal intensity on bilateral optic nerves. A contrast-enhanced T1 weighted image showed enhancement along the bilateral optic nerve sheath. Moreover, diffusion-weighted image (DWI) and an apparent diffusion coefficient map showed markedly restricted diffusion on bilateral optic nerves. Although MR findings of T2-weighted and contrast enhanced T1-weighted images may be nonspecific, the DWI finding of cytotoxic edema of bilateral optic nerves will be helpful for the diagnosis of acute ischemic optic neuropathy after spine surgery.

Idiopathic hypertrophic cranial pachymeningitis: Three biopsy-proven cases including one case with abdominal pseudotumor and review of the literature

Hypertrophic pachymeningitis (HP) is a rare disorder of diverse etiology. It presents with headaches, cranial neuropathies and ataxia occurring alone or in combination. Dural biopsy is essential to exclude secondary causes of pachymeningitis. There is paucity of data on biopsied cases of HP. We report three biopsy-proven cases of idiopathic hypertrophic cranial pachymeningitis. All our patients had headaches and multiple cranial neuropathies; ataxia was seen in one patient. One patient had recurrent anterior and posterior cranial neuropathies, while one each had recurrent anterior and posterior cranial neuropathies. Two patients had profound irreversible mono-ocular visual loss. All of them showed prominent pachymeningeal thickening on imaging. Infarcts were seen in one patient, which have rarely been documented. All patients showed biopsy evidence of meningeal thickening and nonspecific chronic inflammation of the dura. The disease may have a remitting and relapsing course, and usually responds to steroids. Clinical improvement was excellent in two patients and modest in one on steroid therapy. All our patients required azathioprine during the course of therapy. Early institution and long-term maintenance of steroid therapy prevents neurologic sequelae. Occurrence of abdominal inflammatory pseudotumor in a patient of HP possibly as part of multifocal fibrosclerosis has not been described earlier.

Magnetic Resonance Imaging of the Oculomotor Nerve

Oculomotor/cranial nerve III palsy is caused by numerous etiologies involving the brainstem, subarachnoid space, cavernous sinus or superior orbital fissure or orbit. Magnetic resonance imaging (MRI) is the most suitable neuro-imaging technique in patients with this presentation to rule out a mass, aneurysm or ischemic vasculopathy. A pictorial review of various pathologies affecting the oculomotor nerve is presented along with their MRI morphology.

Multiple cranial nerve enhancement in mitochondrial neurogastrointestinal encephalomyopathy

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare disease that often presents with nonspecific white matter abnormalities on magnetic resonance imaging. Ptosis and ophthalmoparesis are a part of its clinical features. We report multiple cranial nerve contrast enhancement on magnetic resonance imaging in a patient with MNGIE and postulate that demyelination may be the responsible substrate for this previously unreported finding. This finding may also explain the cranial neuropathies that patients with MNGIE have.

[Cranial nerves - spectrum of inflammatory and tumorous changes]

Inflammatory processes as well as primary and secondary tumorous changes may involve cranial nerves causing neurological deficits. In addition to neurologists, ENT physicians, ophthalmologists and maxillofacial surgeons, radiologists play an important role in the investigation of patients with cranial nerve symptoms. Multidetector computed tomography (MDCT) and particularly magnetic resonance imaging (MRI) allow the depiction of the cranial nerve anatomy and pathological neural changes. This article briefly describes the imaging techniques in MDCT and MRI and is dedicated to the radiological presentation of inflammatory and tumorous cranial nerve pathologies.

Isolated cranial nerve enhancement in metachromatic leukodystrophy

Metachromatic leukodystrophy is a lysosomal storage disorder with an estimated incidence of 1:40,000. Magnetic resonance imaging at time of diagnosis often shows symmetric white matter involvement, sparing the arcuate fibers. A 25-month-old female child presented with a cranial neuropathy, a spastic gait, decreased leukocyte arylsulfatase-A activity, and elevated urinary sulfatides. Magnetic resonance imaging revealed multiple cranial nerve enhancement, without intraparenchymal white matter involvement.

Imaging the cranial nerves: Part I: methodology, infectious and inflammatory, traumatic and congenital lesions

Many disease processes manifest either primarily or secondarily by cranial nerve deficits. Neurologists, ENT surgeons, ophthalmologists and maxillo-facial surgeons are often confronted with patients with symptoms and signs of cranial nerve dysfunction. Seeking the cause of this dysfunction is a common indication for imaging. In recent decades we have witnessed an unprecedented improvement in imaging techniques, allowing direct visualization of increasingly small anatomic structures. The emergence of volumetric CT scanners, higher field MR scanners in clinical practice and higher resolution MR sequences has made a tremendous contribution to the development of cranial nerve imaging. The use of surface coils and parallel imaging allows sub-millimetric visualization of nerve branches and volumetric 3D imaging. Both with CT and MR, multiplanar and curved reconstructions can follow the entire course of a cranial nerve or branch, improving tremendously our diagnostic yield of neural pathology. This review article will focus on the contribution of current imaging techniques in the depiction of normal anatomy and on infectious and inflammatory, traumatic and congenital pathology affecting the cranial nerves. A detailed discussion of individual cranial nerves lesions is beyond the scope of this article.

Imaging the cranial nerves: part II: primary and secondary neoplastic conditions and neurovascular conflicts

There have been unprecedented improvements in cross-sectional imaging in the last decades. The emergence of volumetric CT, higher field MR scanners and higher resolution MR sequences is largely responsible for the increasing diagnostic yield of imaging in patients presenting with cranial nerve deficits. The introduction of parallel MR imaging in combination with small surface coils allows the depiction of submillimetric nerves and nerve branches, and volumetric CT and MR imaging is able to provide high quality multiplanar and curved reconstructions that can follow the often complex course of cranial nerves. Seeking the cause of a cranial nerve deficit is a common indication for imaging, and it is not uncommon that radiologists are the first specialists to see a patient with a cranial neuropathy. To increase the diagnostic yield of imaging, high-resolution studies with smaller fields of view are required. To keep imaging studies within a reasonable time frame, it is mandatory to tailor the study according to neuro-topographic testing. This review article focuses on the contribution of current imaging techniques in the depiction of primary and secondary neoplastic conditions affecting the cranial nerves as well as on neurovascular conflicts, an increasingly recognized cause of cranial neuralgias.