Overview
CSF examination part six covers special investigations used to identify cerebrospinal fluid leakage and to evaluate intrathecal immunoglobulin synthesis. This includes assessment of rhinorrhoea and otorrhoea following trauma or surgery and the use of CSF protein electrophoresis. Protein electrophoresis of CSF differs from serum by the presence of a prominent transthyretin band and an extra transferrin band known as beta-2 transferrin or tau protein. These features help confirm whether a submitted clear fluid is CSF and assist in diagnosing neurological disorders associated with abnormal immunoglobulin production.
Symptoms
Patients with CSF leakage may present with clear, watery fluid discharge from the nose or ear, especially after head injury or neurosurgical procedures. Recurrent headaches, postural symptoms, or repeated episodes of meningitis may be seen due to continuous CSF leak. Conditions associated with abnormal CSF electrophoresis findings may present with neurological symptoms such as visual disturbances, sensory deficits, motor weakness, or relapsing neurological signs seen in demyelinating disorders. In some cases, abnormalities are detected during the investigation of unexplained neurological symptoms.
Causes
Rhinorrhoea and otorrhoea are caused by defects in the skull base or temporal bone following trauma, surgery, congenital anomalies, or erosion due to infection or tumors. Leakage of CSF increases the risk of ascending infections and recurrent meningitis. Oligoclonal bands detected on CSF protein electrophoresis are caused by intrathecal synthesis of immunoglobulins. These bands are commonly seen in multiple sclerosis and are also present in subacute sclerosing panencephalitis, viral infections of the central nervous system, neurosyphilis, and Guillain–Barré syndrome. Presence of beta-2 transferrin in nasal or ear fluid confirms CSF origin.
Risk Factors
Risk factors for CSF leakage include head trauma, neurosurgical interventions, skull base fractures, congenital skull defects, and chronic infections eroding bone structures. Patients with untreated CSF leaks are at increased risk of recurrent meningitis. Risk factors for abnormal CSF electrophoresis include autoimmune neurological diseases, chronic infections of the central nervous system, and inflammatory or demyelinating disorders. Lack of access to advanced diagnostic facilities may delay accurate identification of CSF leakage.
Prevention
Prevention focuses on early identification and confirmation of CSF leakage to reduce the risk of recurrent meningitis. Accurate laboratory confirmation using protein electrophoresis and detection of beta-2 transferrin ensures correct diagnosis. Timely surgical repair of skull base defects prevents persistent leakage. Proper handling and analysis of CSF samples improve diagnostic accuracy in electrophoresis. Early diagnosis and management of demyelinating and inflammatory neurological disorders help prevent disease progression and long-term neurological complications.
