an inflammation of the arachnoid membrane of the brain or spinal cord. Arachnoiditis was first described by the German physician Böninghausen (1897), and spinal arachnoiditis was described by the German physician A. Schlosinger (1898). Arachnoiditis may develop as a complication of influenza, typhoid, tuberculosis, syphilis, and other infectious diseases. It also appears in connection with inflammations of the ear or paranasal cavities, cranial and spinal injuries, and chronic poisonings (lead, arsenic). The clinical symptoms of arachnoiditis vary with the region of the brain in which it develops. The most common symptom of cerebral arachnoiditis is headache, sometimes accompanied by vomiting—less often by epileptic seizures, weakness in the extremities, impairment of vision and hearing, strabismus, diplopia, vertigo, and unsteady gait. In spinal arachnoiditis, the nerve roots and nerves, and sometimes spinal tissue as well, are injured; pain occurs in the trunk, arms, and legs, and occasionally there is weakness in the arms and legs.

Treatment is aimed at lowering intracranial pressure and decreasing inflammation. Vitamin B, iodine preparations, antibiotics, and hexamethylenetetramine are prescribed. When the acute stage passes, hydrogen sulfide and radon baths, mud, and sometimes radiotherapy are used. If the arachnoiditis originates in a limited area of the meninges, the adhesions may be dissected surgically.