# 01 - SECTION 1 Diagnosis of Neurologic Disorders

## SECTION 1 Diagnosis of Neurologic Disorders

Section 1	 Diagnosis of Neurologic 
Disorders
Daniel H. Lowenstein, S. Andrew Josephson, 

Stephen L. Hauser

Approach to the Patient 

with Neurologic Disease
Neurologic diseases are common and costly. According to estimates 
by the World Health Organization, neurologic disorders affect nearly 
one in three individuals and represent the leading cause of disability 
and the second leading cause of death worldwide (Fig. 433-1). These 
numbers have increased significantly over the past 30 years and are 
expected to double by 2050, due to multiple factors, including aging 
of the population, population growth, and a rising prevalence of meta­
bolic risk conditions.
Motor neuron diseases | 0.3%
Multiple sclerosis | 0.4%
Tetanus | 0.9%
Parkinson’s disease | 1.2%
Other neurologic disorders | 1.3%
Encephalitis | 2.4%
Tension-type headache | 2.6%
Brain and other CNS cancer | 2.8%
Traumatic brain injury | 2.9%
Spinal cord injury | 3.5%
Idiopathic epilepsy | 4.9%
Meningitis | 7.9%
Alzheimer’s disease and
other dementias | 10.4%
Migraine | 16.3%
Stroke | 42.2%
DALYs
FIGURE 433-1  Proportional contributions to the overall global burden of neurologic disorders. Proportions (%) of disability-adjusted life-years (DALYs) and deaths. 
(Based on data from GBD 2016 Neurology Collaborators: Lancet Neurol 18:459, 2019.)

Neurologic Disorders
PART 13
Because therapies now exist for many neurologic disorders, a skillful 
approach to diagnosis is essential. Errors commonly result from an over­
reliance on costly neuroimaging procedures and laboratory tests, which, 
while useful, do not substitute for an adequate history and examination. 
The proper approach begins with the patient and focuses the clinical 
problem, first in anatomic and then in pathophysiologic terms; only 
then should a specific neurologic diagnosis be entertained. This method 
ensures that technology is judiciously applied, a correct diagnosis is 
established in an efficient manner, and treatment is promptly initiated.
THE NEUROLOGIC METHOD
■
■DEFINE THE ANATOMY
The first priority is to identify the region of the nervous system that is 
likely to be responsible for the symptoms. Can the disorder be mapped 
to one specific location, is it multifocal, or is a diffuse process present? 
Are the symptoms restricted to the nervous system, or do they arise in 
the context of a systemic illness? Is the problem in the central nervous 
system (CNS), the peripheral nervous system (PNS), or both? In the 
CNS, is the cerebral cortex, basal ganglia, brainstem, cerebellum, or 
spinal cord responsible? Are the pain-sensitive meninges involved? 
In the PNS, could the disorder be located in peripheral nerves and, if 
Multiple sclerosis | 0.2%
Motor neuron diseases | 0.4%
Tetanus | 0.4%
Other neurologic disorders | 0.6%
Encephalitis | 1.1%
Idiopathic epilepsy | 1.4%
Parkinson’s disease | 2.3%
Brain and other CNS cancer | 2.5%
Meningitis | 3.5%
Alzheimer’s disease and
other dementias | 26.4%
Stroke | 61.2%
Deaths