Overview of paraneoplastic cerebellar degeneration
Paraneoplastic cerebellar degeneration, also known as subacute cerebellar degeneration, is the most common neurologic paraneoplastic syndrome involving the central nervous system. Once thought to be relatively rare, follow-up reports in the literature indicate that about half of patients with nonfamilial delayed cerebellar cortical atrophy develop tumors sooner or later, with pathohistological features such as a massive loss of Purkinje cells and an unremarkable infiltration of inflammatory cells in the brain parenchyma.
Etiology.
The etiology is not well understood. PCD is associated with autoimmunity, and patients can detect a variety of antibodies that cross-react against cancer cells and cerebellar Purkinje cells, of which anti-Yo antibodies are the most specific.
Symptoms
The disease is most common in adults, and is slightly more common in women. The disease has an acute or subacute onset, with progressive exacerbation that may peak in hours, days or even weeks, and natural remission is rare. Typical clinical manifestations of cerebellar damage are often present, with gait instability as the first symptom and symmetrical cerebellar ataxia of the trunk and limbs as the main manifestation, which may be accompanied by dysarthria and nystagmus (most often vertical nystagmus). It may be accompanied by dysarthria and nystagmus (mostly vertical nystagmus). Damage to the brain and peripheral nerves may also occur, such as psychiatric symptoms, cognitive function, and pyramidal signs. The disease can appear at any stage of the cancer course, and symptoms of neurologic involvement appear in about half of the patients before the primary cancer is diagnosed.
Examination
1. Laboratory examination
(1) Serum and CSF immunologic specific antibody tests.
(2) Routine blood, urine and stool tests.
2. Other auxiliary examinations
(1) Neurological CT and MRI examination Early CT and MRI examination is normal, late MRI can see cerebellar white matter T2WI high signal extensive cerebellar and brainstem atrophy.
(2) Neuromuscular electrophysiologic examination.
Diagnosis
The clinical manifestations of cerebellar ataxia in patients with tumors can be considered PCD after exclusion of hemorrhage, infarction, and cerebellar metastases by CT and MR.The diagnosis of paraneoplastic cerebellar degeneration is very difficult when there are only manifestations of neurological damage without clinical symptoms and signs of the primary tumor. It is mainly based on the patient’s clinical manifestations and relevant antibody tests, and it is easy to misdiagnose before the primary tumor is found.
Treatment
Currently there is no specific treatment, effective treatment is the basic support, plasma replacement, vitamin drugs, corticosteroids and immunosuppressants can be applied, the efficacy of which has not been proved in some patients after treatment of primary tumors, the symptoms of this syndrome early diagnosis and treatment can lead to symptomatic relief of some patients early detection of potential tumors and early treatment, which can improve the patient’s quality of life and prolong the lifespan.
Prognosis
Prognosis varies depending on the systemic tumor causing the syndrome, as well as the location and extent of neurologic damage.