Paraneoplastic neurological syndromes

Paraneoplastic neurological syndromes (PNS) are a group of autoimmune diseases in which the body's immune system attacks healthy cells of the nervous system. 

They occur during the development of a malignant neoplasm, but autoimmune mechanisms are manifested due to specific antibodies that are directed against the tumor and components of the nervous system.

Symptoms.

• Encephalomyelitis is an autoimmune lesion of the brain and spinal cord. Depending on the location of the lesion, there may be various symptoms. For example, short-term memory loss, epileptic seizures, mental manifestations, impaired sensitivity or weakness in the extremities.
• Limbic encephalitis is an autoimmune lesion of the structure of the brain – the limbic system, which controls emotions, behavior and certain memory functions. Patients with this disorder may experience mood changes, memory loss, epileptic seizures, hallucinations, or drowsiness. An MRI scan of the brain is required for diagnosis.
• Rapidly progressing cerebellar syndrome – instability when walking, impaired coordination, dizziness, nausea, involuntary eye movements, double vision, speech disorders, handwriting changes.
• Opsoclonus-myoclonus syndrome – involuntary short-term contractions of individual muscles.
• Sensory neuropathy – impaired sensitivity: pain, burning, numbness in the hands and feet).
• Pseudo-obstruction of the gastrointestinal tract – periodic abdominal pain, bloating, constipation and vomiting without signs of mechanical obstruction.
• Myasthenic Lambert-Eaton syndrome is a violation of the connection between nerves and muscles. Symptoms: weakness mainly of the leg muscles, fatigue, difficulty swallowing, speech disorders, double vision.
• Rigid man syndrome – muscle rigidity (tension), most often in the lower back and leg muscles, as well as painful muscle spasms.
• Neuromyotonia (Isaacs syndrome), Morvan syndrome – specific muscle twitching, muscle spasms, increased sweating and impaired relaxation after strong muscle contraction.
• Polyradiculoneuropathy is an autoimmune process that affects the peripheral nerves and roots of the spinal cord, which leads to impaired sensitivity and weakness in the legs and arms. 
• Myelopathy is a lesion of the spinal cord at a certain level. Complaints and symptoms depend on the level of the lesion, the syndrome can manifest as weakness and numbness to a certain level of the body, as well as impaired bowel and bladder functions.

In general, paraneoplastic neurological syndromes may have various manifestations. 

• And if specific antineuronal antibodies are found in the test results, it is important to consult a neurologist to assess the neurological status and the need for additional research.

Also, these syndromes are associated with a certain malignant tumor. 

• Most often these are lung cancer, various neuroendocrine tumors, neuroblastoma, thymoma, breast cancer, ovarian cancer, testicular cancer, Hodgkin's lymphoma, etc.

It should be noted that in 65% of cases, PNS is preceded by symptoms associated with oncology, i.e. first a neurological disorder is diagnosed, and later patients develop symptoms associated with the primary tumor. 

• In this regard, early diagnosis of PNS is very important for timely examination and treatment.

Diagnostics.

Depending on the symptoms, various studies are conducted. An analysis for antineuronal antibodies in the blood and cerebrospinal fluid is mandatory. MRI of the brain, needle electromyography (EMG), electroneuromyography (ENMG), etc. can also be performed.

Treatment.

Currently, PNS treatment is carried out comprehensively: symptomatic therapy, treatment of cancer education and immunosuppressive therapy. 

An important point is precisely the early diagnosis of cancer and the appropriate immediate treatment.

• Effective antitumor therapy can lead to a decrease in PNS symptoms.

Specialists prescribe immunosuppressive therapy individually based on symptoms and determination of contraindications to therapy. 

If you have detected antineuronal antibodies or have neurological symptoms on the background of cancer, we recommend that you contact the Center for Neuromuscular Pathology MCSC named after A.S. Loginov for consultation.

On the basis of the neurological department during hospitalization, it is possible to conduct a comprehensive examination that will help clarify the diagnosis and select therapy based on the latest international research data.