NEURAL DISORDERS - Medicine for Mountaineering and Other Wilderness Activities - page 184

CHAPTER 14
NEURAL DISORDERS
James A. Wilkerson, M.D.
Principal Contributor
The nervous system has two major components, the central nervous system (CNS), which
consists of the brain and spinal cord, and the peripheral nervous system, the numerous
nerves that transmit impulses from and to the CNS. Almost everything that happens in the
body—voluntary and involuntary movement, respiration, blood circulation, even endocrine
function—is controlled or regulated by the nervous system. The diseases of this complex
system are numerous and often disabling. However, most of these diseases come on too
slowly to create problems on a wilderness outing, even on trips lasting several months.
SIGNS AND SYMPTOMS
The signs and symptoms produced by diseases of the nervous system consist of:
Altered intellectual function
Impaired control of movement (motor disturbances)
Sensory disorders
Loss of function of specific nerves
A group of unrelated, less specific signs that includes headache, nausea and vomiting,
and changes in pulse rate and blood pressure
Altered Intellect
Alterations of intellectual function usually produce personality changes first, most com-
monly increased irritability or silliness. Impairment of contact with surroundings shows up
later and is manifested initially by forgetfulness and confusion but can progress to hallu-
cinations, delirium, or complete loss of consciousness (coma). Such alterations are typical
features of altitude disorders, particularly highaltitude cerebral edema.
Motor Disturbances
Motor disturbances, when early or mild, result in loss of coordination that causes stum-
bling, falling, or the inability to perform delicate or repetitive movements. More severe dys-
function causes convulsions, weakness, or total paralysis. Paralysis is a typical feature of
vertebral fractures that injure the spinal cord. Bell's palsy is a type of paralysis that involves
the facial muscles.
Sensory Disturbances
Sensory disturbances most commonly consist of paresthesias: tingling or prickly sensa-
tions like those felt when a limb “goes to sleep.” Such sensations may not be indicative of