Neurology is regarded by many as one of the most difficult and
exacting medical specialties. Students and residents who come to
a neurology service for the first time may be easily discouraged, and
may already be intimidated by the complexity of the nervous system
through their brief contact with neuroanatomy, neurophysiology,
neuropathology, neurogenetics, and cell biology. The ritual they
then witness of putting the patient through a series of maneuvers
designed to evoke certain mysterious signs is hardly reassuring;
in fact, the procedure often appears to conceal the intellectual
processes by which neurologic diagnosis is made. Moreover, the students
have had little or no experience with the many special tests used
in neurologic diagnosis—such as lumbar puncture, EMG (electromyography),
electroencephalography, CT, MRI, and other imaging procedures—nor
do they know how to interpret the results of such tests. Neurology
textbooks only confirm their fears as they read the detailed accounts
of the many rare diseases of the nervous system.
The authors believe that many of the difficulties in comprehending
neurology can be overcome by adhering to the basic principles of
clinical medicine. First and foremost, it is necessary to learn and
acquire facility in the use of the clinical method.
Without a full appreciation of this method, the student is virtually
as helpless with a new clinical problem as a botanist or chemist
who would undertake a research problem without understanding the
steps in the scientific method. Even the experienced neurologist
faced with a complex clinical problem depends on this basic approach.
The importance of the clinical method stands out more clearly
in the study of neurologic disease than in certain other fields
of medicine. In most cases, the clinical method consists of an orderly series
of steps, as follows:
The symptoms and signs are secured by history and
The symptoms and physical signs considered relevant to the problem
at hand are interpreted in terms of physiology and anatomy—that
is, one identifies the disorder(s) of function and the anatomic
structure(s) that are implicated.
These analyses permit the physician to localize the disease process,
i.e., to name the part or parts of the nervous system involved.
This step is called anatomic, or topographic, diagnosis.
Often one recognizes a characteristic clustering of symptoms and
signs, constituting a syndrome of anatomic, physiologic,
or temporal type. The formulation and aggregation of symptoms and signs
in cohesive terms is particularly helpful in ascertaining the locus
and nature of the disease. This step is called syndromic
diagnosis and is often conducted in parallel with anatomic
From the anatomic diagnosis and other medical data—particularly
the mode and speed of onset, evolution, and course of the illness,
the involvement of nonneurologic organ systems, the relevant past
and family histories, and the laboratory findings—one deduces
the pathologic diagnosis and, when the mechanism
and causation of the disease can be determined, the etiologic
diagnosis. This may include the rapidly increasing number ...