Paraneoplastic cerebellar degeneration (PCD) is a rare neurological disorder where the immune system, triggered by an underlying cancer, mistakenly attacks the cerebellum, leading to severe coordination and balance issues. Here’s a concise overview based on current knowledge:

Key Features

PET scans or tumor markers to locate occult malignancies.

Cause: An autoimmune response associated with cancers, most commonly small cell lung cancer, breast cancer, ovarian cancer, or lymphoma. The body produces antibodies (e.g., anti-Yo, anti-Hu) that target both tumor cells and cerebellar neurons.

Symptoms:

Ataxia (unsteady gait, difficulty with coordination)

Dysarthria (slurred speech)

Nystagmus (involuntary eye movements)

Tremors or dizziness

Symptoms often progress rapidly over weeks to months.

Diagnosis:

Clinical evaluation of neurological symptoms.

Detection of paraneoplastic antibodies in blood or cerebrospinal fluid (e.g., anti-Yo, anti-Hu, anti-Ri).

Imaging (MRI/CT) to identify underlying tumors; cerebellar atrophy may be seen in later stages.