Definition.—Pachymeningitis is an inflammation of the outer or inner surface of the dura mater (pachymeningitis externa or interna).
Pachymeningitis externa is more of a primary lesion, it always being the result of pressure from morbid growths, caries of the vertebra, or syphilitic deposits. It may be acute or chronic.
In the acute form, the inflammation is generally nbrino-purulent, the symptoms being those of compression-myelitis. The chronic form is generally due to tuberculosis of the vertebrae. (Pott's disease.) The external layer is rough, thickened, and covered with a cheesy material.
Symptoms.—There may be hyperesthesia and motor spasms, to be followed later by anesthesia, paralysis, atrophy of the muscles, and loss of reflexes—Pachymeningitis interna. Hypertrophica or cervicalis hypertrophica, is of an obscure origin. It was first described by Charcot in 1871. It is generally limited to the cervical region. The dura mater is much thickened, which destroys the nerve-roots and causes compression of the cord.
In the early stages of the disease neuralgic pains are experienced in the occipital region and in the upper extremities. There may be hyperesthesia, and sometimes a herpetic eruption is present. As the disease progresses, compression of the cord increases, which results in atrophic paralysis, and which gives rise to hand deformity—claw-hand.
Prognosis.—The disease is progressive and terminates in death.
Treatment.—The treatment recommended, the iodids and electricity, has not been attended with very satisfactory results.