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Symptoms

By Mayo Clinic staff

Signs and symptoms of paraneoplastic syndromes of the nervous system usually develop relatively quickly, over weeks to months. Problems vary, depending on the site of nerve damage, and may include:

• Difficulty walking
• Difficulty maintaining balance
• Loss of muscle coordination
• Loss of muscle tone or weakness
• Loss of fine motor skills, such as picking up objects
• Difficulty swallowing
• Slurred speech
• Memory loss
• Vision problems
• Spinning sensations (vertigo) or dizziness
• Sleep disturbances
• Dementia
• Seizures
• Numbness, tingling or sensory loss in arms and legs

Types of paraneoplastic syndromes
Several different nervous system (neurological) disorders may occur as paraneoplastic syndromes. Each disorder is characterized by nerve damage at particular sites and by certain signs and symptoms.

Also, each of these neurologic disorders may result from a disease mechanism unrelated to cancer. Neurologic disorders are identified as paraneoplastic syndromes only when there is a definite or probable association with cancer.

Common paraneoplastic syndromes of the nervous system include the following disorders:

• Cerebellar degeneration is the loss of nerve cells in the area of the brain that controls muscle functions and balance (cerebellum). Signs and symptoms may include unsteady or impaired walking, lack of muscle coordination in the limbs, inability to maintain posture of the trunk, dizziness, nausea, involuntary eye movement, double vision, difficulty speaking, or difficulty swallowing.
• Limbic encephalitis is inflammation affecting a region of the brain known as the limbic system, which controls emotions, behaviors and certain memory functions. People with this disorder may experience personality changes or mood disturbances, memory loss, seizures, hallucinations, or sleep disturbances.
• Encephalomyelitis is inflammation of the brain and spinal cord. Initial problems may include sensory loss or numbness, but they progress rapidly to include signs and symptoms of cerebellar degeneration or limbic encephalitis. Dysfunction also occurs in the autonomic nervous system, which regulates nonvoluntary body systems. For example, problems may include irregular heartbeats, low blood pressure or respiratory failure.
• Opsoclonus-myoclonus, which disrupts function of the cerebellum, can cause rapid, irregular eye movements (opsoclonus) and involuntary, chaotic muscle jerks (myoclonus) in both the limbs and trunk.
• Stiff man syndrome, or stiff person syndrome, is characterized by progressive, severe muscle stiffness or rigidity, mainly affecting the spine and legs. It may also cause painful muscle spasms.
• Lambert-Eaton myasthenic syndrome is caused by disrupted communication between nerves and muscles. Signs and symptoms include muscle weakness, fatigue, difficulty swallowing, difficulty speaking, irregular eye movement and double vision. Autonomic problems can include dry mouth, impotence and failure to sweat.
• Myasthenia gravis is characterized by weakness and rapid fatigue of any of the muscles that are under voluntary control, including muscles in the face, eyes, arms and legs. The muscles involved in chewing, swallowing, talking and breathing may be affected as well.
• Neuromyotonia — also known as Isaac's syndrome — is characterized by abnormal impulses in nerve cells outside the brain and spinal cord (peripheral nerves) that control muscle movement. These impulses can cause twitching, muscle rippling that looks like a "bag of worms," progressive stiffness, muscle cramps, slowed movement and other muscle impairments.
• Peripheral neuropathy is damage to nerves that transmit messages from the brain or spinal column to the rest of the body. Paraneoplastic syndromes may include damage to the nerves that regulate non-voluntary body functions, such as heart rate, blood pressure, perspiration, and bowel and bladder functions (autonomic neuropathy), as well as damage to sensory nerves in the peripheral nervous system, including nerves to the face, eye muscles, throat, arms, legs and torso (sensory neuropathy).

When to see a doctor
The signs and symptoms of paraneoplastic syndromes of the nervous system are not specific to these disorders. They may be an indication of any number of conditions. If you have any problems suggesting a paraneoplastic syndrome, see your doctor as soon as possible for a diagnosis and appropriate care.

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