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

Abstract

We report an autopsy case of paraneoplastic opsoclonus-myoclonus-ataxia syndrome associated with small cell carcinoma of the lung. Chemotherapy and lung lobectomy resulted in complete tumor remission and disappearance of myoclonus. However, emotional and behavioral disturbances relapsed and remitted associated with exacerbation of truncal ataxia and ocular flutter, which responded favorably to prednisolone. At autopsy, after 2 years and 11 months of illness, there was no recurrence of cancer. Neuropathologically, only the cerebellum was affected, with diffuse loss of Purkinje cells and dentate neurons, suggesting that the paraneoplastic cerebellar involvement may be responsible for the cognitive affective symptoms in our patient.

Posterior Reversible Encephalopathy Syndrome Presenting as Opsoclonus-Myoclonus

“…Lesions of the pons involving damage to the omnipause cells, which normally inhibit the burst neurons responsible for generating the saccadic impulse,7 or cerebellar lesions interrupting normal vermian inhibition of the fastigial nucleus, which regulates vestibular nuclear tone to burst neurons,8–11 have been suspected. Impairment of the dentatothalamocortical pathway has also been suggested,12 and supported by studies that have iden-tifed histological and biochemical alterations in the dentate nuclei 13,14. Concurrent pontine and cerebellar involvement has also been proposed 15…”

Electrophysiological evidence of cerebral dysfunction in childhood opsoclonus-myoclonus syndrome

“…In this study, a neuroimaging abnormality in the cerebellum and midbrain was demonstrated in Patients 1 and 3, respectively. Few studies have been conducted concerning the autopsy brain finding of OMS, but some case reports have disclosed a reduced number of Purkinje cells in the cerebellum 7. Moreover, surface‐binding antibodies against cerebellar neurons were demonstrated in children with OMS 8.…”

Paraneoplastic movement disorders

“…After exclusion of structural and infective causes, OMS can be either idiopathic or paraneoplastic 27. Median age in one comparative study was 66 years in the paraneoplastic group and 40 in the idiopathic group, with none in the paraneoplastic group being younger than 50 years 28. Encephalopathy was almost exclusively seen in the paraneoplastic group and this could be severe and fatal in some.…”

“…Encephalopathy was almost exclusively seen in the paraneoplastic group and this could be severe and fatal in some. In most cases CSF and MRI brain scans are entirely normal or show nonspecific changes in the brainstem and cerebellum in a minority 28…”

“…Antibody tests are commonly negative. In adults, imaging may detect small cell lung cancer, breast cancer, or rarely other cancers (kidney, stomach, thyroid, pancreas, ovary, lymphoma, thymus, adult neuroblatoma, or sarcoma) 28–36. In most adult cases however, an initial search for cancer will prove negative.…”