mans. The pain, however, is more intense,
and the disease progresses more continuously, and is uninfluenced by
treatment. The changes in the vertebrae, as seen in skiagrams, are
helpful in diagnosis. The growth may encroach upon the vertebral canal
and cause pressure on the cord (p. 451). In the sacrum--the most
common site--the tumour implicates the sacral nerves, and causes
symptoms of intractable sciatica; and the real nature of the disease
is often only detected on making a rectal examination.

_Secondary cancer_ is a common disease, particularly in cases of
advanced scirrhus of the breast. It leads to extensive softening of
the bodies of the vertebrae, so that they yield under the weight of the
body, as in Pott's disease. Clinically it is associated with severe
pain in the region of the vertebrae affected, and along the course of
the nerves emerging in the neighbourhood. If paralysis occurs from
the cancerous bodies pressing upon the cord (_paraplegia dolorosa_),
it is of rapid development, often becoming complete in a few hours.
When the cervical cord is compressed all four limbs are paralysed, and
from interference with respiration, the condition is fatal within a
few days.

#Actinomycosis#, #Blastomycosis#, and #Hydatid Cysts# also occur in
the vertebrae, and are difficult to diagnose from tuberculous disease.

#Typhoid Spine.#--An acute infective condition of the vertebrae,
intervertebral discs, and spinal ligaments occasionally occurs during
convalescence from typhoid fever. The lumbar region is most frequently
affected, and the X-rays reveal inflammatory changes in the bones,
disappearance of the discs, and, in the later stages, deposits of new
bone leading to synostosis of adjacent vertebrae. The onset, which may
be gradual or sudden, is attended with intense pain, and tenderness
over the affected vertebrae. The temperature is raised, and other signs
of an acute infective process are present. In a few cases there are
symptoms of involvement of the membranes and cord. With prolonged rest
and immobilisation of the spine the inflammation usually subsides, but
sometimes it goes on to suppuration.

#Hysterical Spine.#--This term is applied to a functional affection of
the spine occasionally met with in neurotic females between the ages
of seventeen and thirty, and liable to be mistaken for Pott's disease.
The patient complains of pain in some part of the spine--usually the
cervico-thoracic or thoracico-lumbar