Pathophysiology
The authors suggest that cerebellar hypermetabolism observed in this case could be attributed to an acute inflammatory process linked to an immunological reaction [PMID:16543536].
Reduction in cerebellar P/Q-type VGCC quantity, as evidenced by Scatchard analysis, was observed in PCD-LEMS patients compared to controls, suggesting these channels are immunological targets [PMID:12509844].
The study highlights that the molecular layer, rich in P/Q-type VGCCs, shows significant reductions in these channels, pointing to its critical role in the disease process [PMID:12509844].
Immunoelectron microscopy identified that antibodies in PCD patients bind to clusters of ribosomes, granular endoplasmic reticulum, and Golgi complex vesicles in Purkinje cells, suggesting an autoimmune mechanism targeting cerebellar tissue [PMID:3045692].
Diagnosis
A patient with paraneoplastic cerebellar degeneration exhibited cerebellar hypermetabolism and increased perfusion on brain FDG-PET scan during the acute stage, suggesting this imaging technique may aid in diagnosis [PMID:16543536].
Autoradiography revealed markedly reduced toxin binding sites of P/Q-type VGCCs, particularly in the molecular layer, in PCD-LEMS patients compared to controls [PMID:12509844].
Sera from PCD patients with gynecologic cancer exhibited unique cytoplasmic staining patterns in Purkinje cells, distinguishing them from PCD linked to small cell lung cancer, non-neurologic cancer patients, and healthy controls [PMID:3045692].
Differential Diagnosis
No characteristic antibodies targeting Purkinje cells were found in PCD patients with small cell lung cancer, aiding in differential diagnosis by excluding PCD in such cases [PMID:3045692].
Management
Following two cycles of chemotherapy, there was a marked decrease in cerebellar hypermetabolism observed on follow-up FDG-PET scan 3 months later [PMID:16543536].
References
1 Choi KD, Kim JS, Park SH, Kim YK, Kim SE, Smitt PS. Cerebellar hypermetabolism in paraneoplastic cerebellar degeneration. Journal of neurology, neurosurgery, and psychiatry 2006. link 2 Fukuda T, Motomura M, Nakao Y, Shiraishi H, Yoshimura T, Iwanaga K et al.. Reduction of P/Q-type calcium channels in the postmortem cerebellum of paraneoplastic cerebellar degeneration with Lambert-Eaton myasthenic syndrome. Annals of neurology 2003. link 3 Rodriguez M, Truh LI, O'Neill BP, Lennon VA. Autoimmune paraneoplastic cerebellar degeneration: ultrastructural localization of antibody-binding sites in Purkinje cells. Neurology 1988. link