Question: What is (are) Subacute cerebellar degeneration ?
Answer: Subacute cerebellar degeneration is the breakdown of the area of the brain that controls muscle coordination and balance (the cerebellum). Less commonly, the area connecting the spinal cord to the brain is involved. Subacute cerebellar degeneration may occur in association with a cancer (paraneoplastic cerebellar degeneration) or lack of thiamine (alcoholic or nutritional cerebellar degeneration). Signs and symptoms may include ataxia, speech and swallowing problems, dementia, vision problems, and vertigo.
Source: GARD

Question: What are the symptoms of Subacute cerebellar degeneration ?
Answer: What are the signs and symptoms of subacute cerebellar degeneration? Signs and symptoms of subacute cerebellar degeneration, include ataxia, speech and swallowing problems, dementia (in about half of people with this condition), and difficulty walking. People with subacute cerebellar degeneration due to thiamine deficiency may also experience quick involuntary movements of the eyeball (nystagmus), double-vision, dizziness, and paralysis of the eye muscles. In paraneoplastic cerebellar degeneration, dizziness, nausea, and vomiting may precede the neurological symptoms. Paraneoplastic cerebellar degeneration may occur in association with Lambert Eaton myasthenic syndrome or encephalomyelitis.
Source: GARD

Question: What causes Subacute cerebellar degeneration ?
Answer: What causes subacute cerebellar degeneration? Subacute cerebellar degeneration may occur when the body's immune system attacks healthy tissue, either for unknown reasons or as an abnormal reaction to an underlying cancer. These cases are referred to as paraneoplastic cerebellar degeneration. Subacute cerebellar degeneration may also occur due to thiamine deficiency. Causes of thiamin deficiency include alcoholism, recurrent vomiting, gastric surgery, and diets poor in this B vitamin. These cases are referred to as alcoholic/nutritional cerebellar degeneration. For further information pertaining to the neurological effects of severe thiamine deficiency, see the following link to the Wernicke-Korsakoff syndrome resource page. http://rarediseases.info.nih.gov/gard/6843/wernicke-korsakoff-syndrome/Resources/1
Source: GARD