Clinical Aspects of Vertigo and Dizziness: What Should the Radiologist Know?

Dizziness and vertigo are common complaints in both emergency and outpatient settings, requiring careful evaluation to determine appropriate diagnosis and treatment. Differentiating between peripheral and central causes of dizziness is crucial for effective management. Peripheral causes, such as vestibular neuritis, benign paroxysmal positional vertigo, and Ménière's disease, are contrasted with central causes such as stroke, demyelinating diseases, and posterior fossa tumors. Diagnostic approaches include assessing nystagmus patterns, the vestibulo-ocular reflex, and the HINTS Plus test. Vestibular disorders are classified as acute, episodic, or chronic based on duration and symptom presentation. Imaging plays a significant role in identifying central causes when clinical findings are inconclusive. This paper provides a comprehensive overview of the clinical evaluation and diagnostic methods for dizziness and vertigo, with emphasis on distinguishing peripheral from central etiologies.

Vertigo Related to Central Nervous System Disorders

PURPOSE OF REVIEW

This article provides an overview of the numerous causes of vertigo and dizziness that are due to central nervous system (CNS) pathology and guides clinicians in formulating a differential diagnosis and treating patients with CNS causes of vertigo.

RECENT FINDINGS

Specific autoimmune vestibulocerebellar syndromes may now be tested for, and this article discusses the antibodies known to cause such syndromes. Superficial siderosis can be more accurately diagnosed with imaging studies, and treatment using iron chelation has recently been studied but has not yet been established as an effective treatment. Central autonomic network damage in the brain can cause central orthostatic hypotension in some neurodegenerative diseases, and medication has been approved for treatment.

SUMMARY

CNS causes of vertigo are numerous and important for clinicians to recognize. Examination findings are still an extremely valuable way to diagnose central vertigo; therefore, learning how to differentiate central from peripheral vertigo based on examination is an important skill. CNS causes of vertigo often have available treatments.

[Superficial siderosis of the central nervous system caused by myxopapillary ependymoma of conus medullaris and cauda equine: a case report and literature review]

Superficial siderosis of the central nervous system (SSCNS) is a rare disorder caused by hemosiderin deposits in the subpial layers of the brain and spinal cord due to prolonged or recurrent low-grade bleeding into the cerebrospinal fluid (CSF). Central nervous system tumor could be one of the sources of bleeding. Some problems exist at present regarding the diagnosis and treatment of SSCNS in China. On account of fewer cases, the insufficient awareness of the condition, and the lack of long-term follow-up data, enough attention has not been paid to etiological diagnosis. The speculative high rate of missed diagnoses of SSCNS indicates a great disparity in the treatment from the world's advanced level. Related data of clinical and basic research need to accumulate as soon as possible to promote the clinical diagnosis and treatment of the disease. The progressive neurological deficits are involved in the typical clinical manifestations of SSCNS with a triad of bilateral symmetrical sensorineural hearing loss, cerebellar ataxia and signs of corticospinal tract dysfunction. Nevertheless, there are few patients with the triad signs at the same time, which lead to a delayed diagnosis or misdiagnosis. Detection of this disease was commonly post-mortem until the advent of MRI with signal and location characteristics, which made diagnosis easier. Siderosis appears as a hypointense rim covering the surface of the cerebellum, the brain stem, the spinal cord, similar to a black pencil line, thin on SE-T2-weighted images, thick and conspicuous on GE-T2-weighted images or on susceptibility-weighted imaging (SWI). The only effective way of treating the disorder is to identify the source of bleeding and remove it. MR examination is useful for seeking a source of bleeding too. Therefore, once superficial siderosis is considered, lesions of the central nervous system must be searched using MRI of the brain and spine. We report here a 37-year-old male diagnosed of SSCNS with the classical clinical symptoms of cerebellar ataxia, sensorineural hearing loss and myelopathy. T2-weighed MRI showed characteristic marginal hypo-intensity around the central nervous system. Etiological explorations revealed a large conus medullaris / cauda equina ependymoma filling the lumbosacral spinal canal, a myxopapillary ependymoma (MPE) confirmed by surgical resection and histopathological examination. The related literature was reviewed to ascertain the mechanism of SSCNS secondary to MPE, and to discuss the pathogenesis, clinical features, diagnosis and treatment of SSCNS. This paper aims to improve the awareness of SSCNS and diagnostic level, and to lay stress on the etiological explorations that is beneficial to the development of exact treatment plan.

Imaging of cranial nerves: a pictorial overview

The human body has 12 pairs of cranial nerves that control motor and sensory functions of the head and neck. The anatomy of cranial nerves is complex and its knowledge is crucial to detect pathological alterations in case of nervous disorders. Therefore, it is necessary to know the most frequent pathologies that may involve cranial nerves and recognize their typical characteristics of imaging. Cranial nerve dysfunctions may be the result of pathological processes of the cranial nerve itself or be related to tumors, inflammation, infectious processes, or traumatic injuries of adjacent structures. Magnetic resonance imaging (MRI) is considered the gold standard in the study of the cranial nerves. Computed tomography (CT) allows, usually, an indirect view of the nerve and is useful to demonstrate the intraosseous segments of cranial nerves, the foramina through which they exit skull base and their pathologic changes. The article is a complete pictorial overview of the imaging of cranial nerves, with anatomic and pathologic descriptions and great attention to illustrative depiction. We believe that it could be a useful guide for radiologists and neuroradiologists to review the anatomy and the most important pathologies that involve cranial nerves and their differential diagnosis.

Superficial siderosis due to filum terminale tumor: An uncommon cause of cranial nerve dysfunction

If superficial siderosis is suspected based on clinical presentation, susceptibility weighted imaging should be undertaken in addition to standard MRI sequences as it is more sensitive than T2 weighted imaging. Once diagnosed, imaging of the entire brain and spine must be undertaken to assess for an underlying cause.

Cerebellar Ataxia in Children: A Clinical and MRI Approach to the Differential Diagnosis

: The cerebellum has long been recognized as a fundamental structure in motor coordination. Structural cerebellar abnormalities and diseases involving the cerebellum are relatively common in children. The not always specific clinical presentation of ataxia, incoordination, and balance impairment can often be a challenge to attain a precise diagnosis. Continuous advances in genetic research and moreover the constant development in neuroimaging modalities, particularly in the field of magnetic resonance imaging, have promoted a better understanding of cerebellar diseases and led to several modifications in their classification in recent years. Thorough clinical and neuroimaging investigation is recommended for proper diagnosis. This review outlines an update of causes of cerebellar disorders that present clinically with ataxia in the pediatric population. These conditions were classified in 2 major groups, namely genetic malformations and acquired or disruptive disorders recognizable by neuroimaging and subsequently according to their features during the prenatal and postnatal periods.

Superficial siderosis: Chronic sequelae following brain hemorrhage

Superficial siderosis is a rare disease of the central nervous system. It is caused by hemosiderin deposition usually following subarachnoid hemorrhage. We report a 67-year-old man with history of motor vehicle accident in 1974 who presents with tremors, worsening ataxia, and impaired auditory, olfactory, and gustatory sensation. The patient was evaluated with magnetic resonance imaging of the brain that showed areas of superficial low T2 signal throughout the posterior fossa, ventricles, sulci, and cisterns, most conspicuous on the gradient-recalled echo T2* susceptibility-weighted sequence. These findings are compatible with old blood products (hemosiderin) and the diagnosis of superficial siderosis.

Superficial siderosis misdiagnosed as idiopathic bilateral neurosensorial deafness

Superficial siderosis (SS) is a rare condition resulting from different sources of bleeding into the subpial space. The most common symptoms are: hypoacusia, ataxia, incontinence, dementia and parkinsonism. Since several neurodegenerative disorders may present with same clinical features, SS is often misdiagnosed. Here we present a case of SS misdiagnosed as idiopathic bilateral neurosensorial deafness.

Two-year observational study of deferiprone in superficial siderosis

INTRODUCTION

Superficial siderosis is a rare, neurodegenerative disease caused by toxic accumulation of hemosiderin on the surface of the brain and the spinal cord, most commonly from chronic subarachnoid hemorrhage.

AIMS

The aim of this study was to assess the clinical and radiological outcomes of superficial siderosis patients using deferiprone, a cell permeant iron chelator. Subjects obtained pre- and post-treatment brain MRIs and weekly laboratory tests. Osirix software was used to develop a method of quantifying hemosiderin deposition. Three-dimensional whole brain images of gradient echo images were rendered and compared by dividing the mean T2 hyperintensity to the maximal cerebrospinal fluid signal.

RESULTS

A total of 38 subjects completed the study, of which clinical and radiological data were available for 30. The average age was 64 years (range 37-86), 53% were male, 94% were white. Nineteen subjects (63%) reported either no progression of disease or an improvement in at least one neurological domain, with 40% of patients reporting a stabilization in hearing function and 30% reporting stable or improved coordination and walking. By MRI, there was an overall mean increase in T2 hyperintensity of the whole brain of 1%-13% over the 2-year time period in half of patients, indicating a reduction hemosiderosis. There were no cases of agranulocytosis, and declines of white blood cells counts and neutrophils averaged <10%. Fatigue was the most common side effect.

CONCLUSION

This is the first long-term prospective study of superficial siderosis on the iron chelator, deferiprone. MRI quantification of hemosiderin appears to demonstrate a measurable reduction in half of patients and this correlated with a stabilized or improving disease course. A future placebo-controlled trial is necessary to determine whether deferiprone is an effective therapy for superficial siderosis.

Superficial siderosis associated with abundant τ and α-synuclein accumulation

A Japanese male developed deafness, pyramidal signs and ataxia at age 50. A cerebrospinal fluid examination showed elevated levels of iron, transferrin and ferritin. Brain MRI showed atrophy of the cerebellum and pons as well as potential iron deposits on the surface of the brain. At autopsy, the brain weighed 1090 g and showed severe atrophy and necrosis of the cerebellum. No vascular malformation was observed. Extensive deposits of hemosiderin that were well stained with Berlin blue and ferritin immunohistochemistry were present at the surface and in the superficial layers of the cerebrum, brainstem, cerebellum and spinal cord. In these regions, numerous AT8 (p-τ)-immunopositive deposits were present in neurons and glia. In addition, phosphorylated α-synuclein-immunopositive Lewy bodies and neurites were observed in the brainstem nuclei. In the present report, the authors derive the novel insight that superficial siderosis is a distinctive entity associated with tauopathy and synucleinopathy.