Autopsy case of opsoclonus-myoclonus-ataxia and cerebellar cognitive affective syndrome associated with small cell carcinoma of the lung

Opsoclonus-Ataxia Syndrome in a Patient With Small-Cell Lung Cancer Treated With Immune Checkpoint Inhibitors

OBJECTIVES

To describe a case of post-immune checkpoint inhibitor (ICI) opsoclonus-myoclonus-ataxia syndrome (OMAS), with complete clinical remission after treatment.

METHODS

A 52-year-old man was admitted because of subacute-onset vertigo, dysarthria, vomiting, and weight loss. He was under atezolizumab (anti-PD-L1) monotherapy (23 cycles) for metastatic small-cell lung cancer, with excellent response.

RESULTS

On examination (1 month after symptom onset), the patient had opsoclonus, dysarthria, severe truncal and gait ataxia, and mild appendicular ataxia without myoclonus (SARA score 26/40). Brain MRI showed mild cerebellar atrophy, and CSF analysis disclosed pleocytosis and oligoclonal bands. Anti-SOX1 antibodies were detected in serum and CSF. Atezolizumab was stopped, and corticosteroids and monthly IV immunoglobulins were administered. Chemotherapy (carboplatin and etoposide) was also started because of cancer progression. Three months later, examination showed regression of the opsoclonus, truncal ataxia, and dysarthria and persistence of very mild gait ataxia (SARA score 3.5/40), which completely regressed at last examination (20 months after onset).

DISCUSSION

The clinical pattern and reversibility bring the present case close to a few patients with paraneoplastic OMAS described before the ICI era. More research is needed to clarify the pathogenesis and outcomes of OMAS in the context of ICI.

Monocentric retrospective clinical outcome in a group of 13 patients with opsoclonus myoclonus syndrome, proposal of diagnostic algorithm and review of the literature

BACKGROUND

Dancing eye syndrome or opsoclonus-myoclonus syndrome (OMS) is a very rare disease (incidence <1/5,000,000 per year), which is more prevalent in young children. Although it is not usually a cause of mortality, the aftermaths are not rare.

METHODS

We performed an observational retrospective review of children diagnosed with OMS in our neuropediatric department from 1996 to 2020, with the objective of assessing the prognostic value of initial clinical features. All medical data from diagnosis to last follow-up were reviewed. We defined unfavorable evolution of OMS as persistence or worsening of symptoms. Subsequently, based on a literature review, our results and experience, a diagnostic algorithm was developed.

RESULTS

A total of 13 OMS patients were included: 61.5% were male (n = 8), median age at diagnosis was 18 months (IR = 76), median treatment delay was 14 days (IR = 146) and OMS score at onset was 8 (IR = 11). The most frequent etiologies were neuroblastoma-associated and idiopathic OMS (38.46%; n = 5) of the patients, followed by post-infectious OMS (n = 3). All the patients were treated with corticosteroids, five required a surgical intervention (neuroblastoma group), and three required adjunctive immune therapy (immunoglobulins, cyclophosphamide and/or rituximab). We detected neurodevelopmental disorders in 38.46% (n = 5) of the patients, mainly attention deficit (n = 4), and persistent sleep disturbances (n = 4). The median OMS score at the end of follow-up was 1 (IR = 3). An important diagnostic delay, OMS score of ≥10 and age >1 year at onset may correlate with a higher risk of aftermaths. We detected a better prognosis in the post-infectious OMS, with full recovery occurring in 2/3 of patients.

CONCLUSIONS

Early clinical suspicion is key to guarantee maximum response of treatment.

Emotional disorders and the cerebellum: Neurobiological substrates, neuropsychiatry, and therapeutic implications

The notion that the cerebellum is devoted exclusively to motor control has been replaced by a more sophisticated understanding of its role in neurological function, one that includes cognition and emotion. Early clinical reports, as well as physiological and behavioral studies in animal models, raised the possibility of a nonmotor role for the cerebellum. Anatomical studies demonstrate cerebellar connectivity with the distributed neural circuits linked with autonomic, sensorimotor, vestibular, associative, and limbic/paralimbic brain areas. Identification of the cerebellar cognitive affective syndrome in adults and children underscored the clinical relevance of the role of the cerebellum in cognition and emotion. It opened new avenues of investigation into higher-order deficits that accompany the ataxias and other cerebellar diseases, as well as the contribution of cerebellar dysfunction to neuropsychiatric and neurocognitive disorders. Brain imaging studies have demonstrated the complexity of cerebellar functional topography, revealing a double representation of the sensorimotor cerebellum in the anterior lobe and lobule VIII and a triple cognitive representation in the cerebellar posterior lobe, as well as representation in the cerebellum of the intrinsic connectivity networks identified in the cerebral hemispheres. This paradigm shift in thinking about the cerebellum has been advanced by the theories of dysmetria of thought and the universal cerebellar transform, harmonizing the dual anatomic realities of homogeneously repeating cerebellar cortical microcircuitry set against the heterogeneous and topographically arranged cerebellar connections with extracerebellar structures. This new appreciation of cerebellar incorporation into circuits that subserve cognition and emotion mandates a deeper understanding of the cerebellum by practitioners in behavioral neurology and neuropsychiatry because it impacts the understanding and diagnosis of disorders of emotion and intellect and has potential for novel cerebellar-based approaches to therapy.

Brain volumetric analysis and cortical thickness in adults with saccadic intrusions (ocular flutter or opsoclonus-myoclonus syndrome)

OBJECTIVES

Ocular flutter (OF) and opsoclonus are considered a continuum with a similar pathogenesis. Due to the rarity of this disease in the adult population, little is known about the brain morphological changes in the chronic phase of the disease.

PATIENTS AND METHODS

Six magnetic resonance imaging from adults with previous history of OF/Opsoclonus and 12 healthy patients (paired by age and sex) were analyzed in order to identify the long term cortical thickness pattern in this rare disease by using Freesurfer.

RESULTS

Patients with OF/Opsoclonus showed reduced cerebellum cortical volume with a subsequent diminution in total cerebellar volume. White mater cerebellum volume was not modified. In addition, we have also identified a significant supratentorial gray matter volume decrease in OF/Opsoclonus patients, involving both the cortical and the subcortical gray matter.

CONCLUSIONS

OF/Opsoclonus in adults may be associated with cortical and subcortical gray matter atrophy, as well as decreased cerebellar cortical volume. Further larger prospective studies are necessary to confirm these results.

Posterior Reversible Encephalopathy Syndrome Presenting as Opsoclonus-Myoclonus

Opsoclonus-myoclonus may be caused by various neurological conditions and toxic-metabolic states, but typically occurs as a parainfectious or paraneoplastic manifestation. The development of opsoclonus-myo-clonus has been variably attributed to lesions in the pons or cerebellum. Herein the authors describe a case of opsoclonus-myoclonus due to posterior reversible encephalopathy syndrome in which magnetic resonance imaging revealed lesions in the region of the cerebellar dentate nuclei. Clinical and radiological resolution of the opsoclonus-myoclonus and of the posterior reversible encephalopathy syndrome followed antihyperten-sive therapy.

Update on paraneoplastic neurological syndromes

PURPOSE OF REVIEW

To describe specificities and new advances in treatment of paraneoplastic neurological syndromes (PNS).

RECENT FINDINGS

PNS are defined as neurological syndromes of unknown cause that often antedate the diagnosis of an underlying cancer that is usually not clinically evident. The clinical signs of PNS are accurately described and 'classical' PNS have been established. Within the context of these syndromes, the concept of limbic encephalitis has evolved dramatically in the last 2 years due to the description of new auto-antibodies. The diagnosis and treatment of the associated cancer remains the key goal of the clinical management of PNS. However, the specific treatment of the neurological symptoms primarily depends on the immunological findings.

SUMMARY

There is increasing recognition of an extensive array of PNS and of several paraneoplastic antibodies as biological markers of these disorders. Basic immunological studies support the pathogenic role of some of these antibodies. Others are only markers of the disease.

Long-term survival in paraneoplastic opsoclonus-myoclonus syndrome associated with small cell lung cancer

Paraneoplastic opsoclonus-myoclonus syndrome (OMS) is associated with small cell lung cancer (SCLC) in adults. Without appropriate treatment for SCLC, all reported patients with SCLC and OMS have died of complications of OMS within 3 months of diagnosis. With appropriate treatment, about half of reported patients have had improvement in neurologic function, and several have become long-term survivors (6-84 months). We report a patient with SCLC who presented with OMS and was refractory to immunosuppressive therapy but responded rapidly to antineoplastic therapy and remains alive with no sign of SCLC recurrence and minimal residual neurologic deficits 30 months after diagnosis. In patients presenting with OMS, early recognition and treatment of the underlying malignancy probably improve the chances for recovery from the OMS with minimal deficit and ultimate survival.