Paraneoplastic syndromes in neuro-ophthalmology

Paraneoplastic vision loss

Paraneoplastic vision loss, which represents a small percentage of paraneoplastic neurologic syndromes, can be a blinding disease. Presenting visual symptoms are variable, making diagnosis challenging. History of the presenting illness, ocular examination, and utilization of various modalities, such as automated perimetry, ocular coherence tomography, and electroretinogram allow for localization of vision loss to the optic nerves or retina, guiding in diagnosis and management. Paraneoplastic vision loss is often painless, bilateral, and subacute, and accompanies other neurologic symptoms but can be the first presenting symptom. Paraneoplastic optic neuropathy has been described in association with several antibodies, but most commonly anti-CRMP5. Cancer-associated retinopathy is the most common paraneoplastic autoimmune retinopathy; however, melanoma-associated retinopathy and bilateral diffuse uveal melanocytic proliferation have also been described to be associated with a paraneoplastic process affecting the retina. Paraneoplastic visual loss is an expanding field and advances in research have improved phenotypic characterization; however, further work is needed to identify more reliable biomarkers of disease and to better understand the underlying mechanisms and management.

[Paraneoplastic ophthalmopathies]

Ocular paraneoplastic syndromes are rare conditions that can affect any part of the eye at any age. Thus, every ophthalmologist should be familiar with their management, as some of them may reveal severe, life-threatening conditions. These consist overwhelmingly of neuro-ophthalmological manifestations, affecting the optic nerve (paraneoplastic optic neuritis), retina (paraneoplastic retinopathy) or neurological pathways generating eye movements (saccadic intrusion, oculomotor palsy, nystagmus...); occasionally, they involve the anterior segment, orbit or uveal tract. As some of these manifestations appear to be quite common and non-specific, any systemic or especially neurologic comorbidities should increase suspicion. Treatment relies first on oncologic management, and then often more targeted therapy for the associated immune involvement.

Paraneoplastic Syndromes in Neuro-ophthalmology

PURPOSE OF REVIEW

This article discusses the varied types of paraneoplastic syndromes that commonly have neuro-ophthalmologic manifestations. Diagnostic considerations and therapeutic options for individual diseases are also discussed.

RECENT FINDINGS

Paraneoplastic syndromes can affect the afferent and efferent visual systems. Paraneoplastic syndromes may result in reduced visual acuity from retinal degeneration, alterations in melanocyte proliferation and uveal thickening, or acquired nystagmus. Ocular motor abnormalities related to paraneoplastic syndromes may present with symptoms from opsoclonus or from neuromuscular junction disease. Diagnosis remains challenging, but serologic identification of some specific antibodies may be helpful or confirmatory. Treatment, in addition to directed therapies against the underlying cancer, often requires systemic corticosteroids, plasma exchange, or immunosuppression, but some specific syndromes improve with use of targeted pharmacologic therapy.

SUMMARY

Diagnosis and therapy of paraneoplastic syndromes presenting with neuro-ophthalmic symptoms remain a challenge, but strategies are evolving and new approaches are on the horizon.

Distinct clinical characteristics of paraneoplastic optic neuropathy

Objective

Paraneoplastic optic neuropathy (PON) is relatively uncommon, and the visual outcomes and prognosis of this disease have not been well documented. The aim of this study was to investigate the clinical features and prognosis of antibody-mediated PON.

Methods

Clinical data were retrospectively collected from hospitalised patients diagnosed with PON at the Neuro-Ophthalmology Department at the Chinese People’s Liberation Army General Hospital from January 2015 to June 2017.

Results

A total of seven patients (four females and three males, 13 involved eyes) were included with a mean age of 56.28±11.32 years (36–70 years). Simultaneous or early sequential bilateral eye involvement (5/7, 71.4%) was common in the patients with PON. Severe vision loss (≤0.1) was seen in 76.9% (10/13) of the eyes. There were 13 eyes in the acute phase of the disease, and six eyes presented with optic disc oedema. All patients had definite evidence of paraneoplastic-associated antibodies (three with serum positive for antiamphilphysin, one for anti-PNMA2 (Ma2/Ta), one for anti-Yo, one for anti-Ma2 and one for anti-CV2). All of the serum samples were negative for myelin oligodendrocyte glycoprotein antibody and two patients companied with seropositive for the aquaporin-4 antibody. Five patients had history of primary malignancy, including thyroid cancer, type B thymoma, testicular seminoma, cervical cancer and lung carcinoma. Two patients had positive paraneoplastic syndrome antibodies (anti-Yo and antiamphiphysin), but the solid tumour had not been found through a PET scan. Visual acuity in 9/13 (69.2%) eyes was below 0.1, and all of the patients survived to the follow-up with no metastatic lesions.

Conclusions

PON is relative rare, with a predominance of bilateral involvement and more with a poor visual prognosis. Paraneoplastic antibody testing can contribute to the diagnosis of PON, distinct from other types of optic neuropathies, which can help doctors to find the primary cancer earlier to guide further treatment.

Anti-Ri-associated paraneoplastic brainstem cerebellar syndrome with coexisting limbic encephalitis in a patient with mixed large cell neuroendocrine lung carcinoma

Paraneoplastic neurologic syndromes (PNS) can be the first manifestations of occult malignancies. If left untreated, PNS often lead to significant morbidity and mortality. Anti-Ri (anti-neuronal nuclear antibody type 2 [ANNA-2]) autoantibodies are commonly associated with breast and small cell lung cancers. Cases of anti-Ri paraneoplastic cerebellar degeneration are reported, but few describe severe nausea and coexisting limbic encephalitis as the major presenting features. We report a 75-year-old woman with medically-intractable emesis, encephalopathy, diplopia, vertigo, and gait ataxia for 3 months. Examination revealed rotary nystagmus, ocular skew deviation, limb dysmetria, and gait ataxia. After two courses of intravenous immunoglobulin, there was minimal improvement. Anti-Ri antibodies were positive in serum only. CT scan identified a 2.0 cm left lung mass, and histopathology revealed large cell neuroendocrine carcinoma with admixed adenocarcinoma non-small cell lung carcinoma (NCSLC). Though the patient achieved nearly complete clinical recovery after tumor resection, anti-Ri levels remained high at 20 months post-resection. To our knowledge this is the first report of a paraneoplastic brainstem cerebellar syndrome with coexisting limbic encephalitis involving anti-Ri positivity and associated mixed neuroendocrine/NSCLC of the lung with marked improvement after tumor resection.

Autoantibody against transient receptor potential M1 cation channels of retinal ON bipolar cells in paraneoplastic vitelliform retinopathy

Background

Paraneoplastic retinopathy is caused by the cross-reaction of neoplasm-directed autoantibodies against retinal antigens and results in retinal damage. Paraneoplastic vitelliform retinopathy, a presumed paraneoplastic retinopathy with features of atypical melanoma-associated retinopathy, has recently been reported in patients with metastatic melanoma. Ocular ultrastructure and its autoantibody localization of paraneoplastic vitelliform retinopathy are still indefinable. This is the first report of anti-transient receptor potential M1 antibody directly against human retinal bipolar dendritic tips in a melanoma patient with paraneoplastic vitelliform retinopathy.

Case presentation

We present a pair of postmortem eyes of an 80-year-old male with metastatic cutaneous melanoma, who developed paraneoplastic vitelliform retinopathy. The autopsied eyes were examined with light microscopy, immunohistochemistry, and transmission electron microscopy. Microscopically, the inner nuclear layer and outer plexiform layer were the most affected retinal structures, with local thinning. The lesions extended to the outer nuclear layer, resulting in focal retinal degeneration, edema, and atrophy. No active inflammation or melanoma cells were observed. Immunohistochemistry showed tightly compact bipolar cell nuclei (protein kinase C alpha/calbindin positive) with blur/loss of ON bipolar cell dendritic tips (transient receptor potential M1 positive) in diffusely condensed outer plexiform layer. The metastatic melanoma cells in his lung also showed immunoreactivity against transient receptor potential M1 antibody. Transmission electron microscopy illustrated degenerated inner nuclear layer with disintegration of cells and loss of cytoplasmic organelles. These cells contained many lysosomal and autophagous bodies and damaged mitochondria. Their nuclei appeared pyknotic and fragmentary. The synapses in the outer plexiform layer were extensively degenerated and replaced with empty vacuoles and disintegrated organelles.

Conclusion

This case provides a convincing histological evidence of melanoma-associated autoantibodies directly against transient receptor potential M1 channels that target the ON bipolar cell structures in the inner nuclear and outer plexiform layers in paraneoplastic vitelliform retinopathy.

Presumed melanoma-associated retinopathy (MAR): a presenting sign of primary small intestinal melanoma?

Melanoma-associated retinopathy is a paraneoplastic retinopathy associated mostly with cutaneous melanoma. In most cases it presents months to years after diagnosis of primary cutaneous melanoma was made or after recurrence. We describe a 55-year-old male patient who presented with symptoms of decreased vision and photopsia. Diagnosis of melanoma-associated retinopathy was made, but no primary cutaneous melanoma was found. 3 months later he developed intestinal perforation due to small intestinal melanoma.