Neurological Disorders due to Systemic Disease by Lewis Steven L

Author:Lewis, Steven L.
Language: eng
Format: epub
Publisher: Wiley
Published: 2012-12-03T16:00:00+00:00

Systemic Cancer and Paraneoplastic Disorders

Vestibulocochlear Nerve and Cerebellum

Systemic neoplasms that affect the vestibular or auditory system are limited mainly to those that have some proclivity to affect the bony labyrinth or the central nervous system. Neoplastic processes that spread to the bone include head and neck squamous cell carcinoma, breast carcinoma, lung adenocarcinoma, renal-cell carcinoma, prostate carcinoma, malignant melanoma, rhabdomyosarcoma, osteosarcoma, and non-Hodgkin's lymphoma. Rhabdomyosarcoma is the most common malignancy of the temporal bone in children. Tumors arising from nearby locations such as meningioma, chordoma, parotid malignancy, and nasopharyngeal carcinoma may spread to the temporal bone affecting auditory or vestibular function.

Leptomeningeal carcinomatosis or lymphomatosis may lead to bilateral hearing and vestibular loss [31]. The vestibulocochlear nerves within the subarachnoid space become seeded with tiny foci of tumor leading to hearing or vestibular dysfunction that may be asymmetric. Leptomeningeal neoplasia also affects the basal cisterns often leading to ataxia and nystagmus from cerebellar dysfunction. In many cases, other cranial neuropathies will also occur causing swallowing difficulty, facial weakness or numbness, diplopia, and dysarthria. Bilateral vestibular loss causes unsteadiness of gait and oscillopsia during head movements. Patients often exhibit falling on Romberg testing during eye closure or when walking on uneven ground. Examination shows bilateral abnormalities in head impulse testing and reduced dynamic visual acuity. A bithermal caloric test or rotational chair testing will confirm severely reduced vestibulo-ocular reflexes.

Paraneoplastic syndromes that may cause dizziness, vertigo, imbalance, and ataxia are mainly those that affect the vestibulocerebellum. The syndromes associated with anti-Purkinje cell antibody (anti-Yo), anti-Tr antibody, and anti-CRMP5 tend to be most strongly associated with cerebellar degeneration [32] (Table 8.2). Histologically, paraneoplastic cerebellar degeneration shows severe loss of cerebellar Purkinje cells and inflammatory infiltrates.

Table 8.2 Selected paraneoplastic syndromes with vestibulocerebellar syndrome.

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