Ovid: Pocket Guide and Toolkit to DeJong’s Neurologic Examination

Authors: Campbell, William W.
Title: Pocket Guide and Toolkit to DeJong’s Neurologic Examination, 1st Edition
> Table of Contents > Section A – Introduction > Chapter 1 – Introduction

Chapter 1
This book is written as a companion and supplement to DeJong’s The Neurologic Examination, 6th edition.
The book has been streamlined, all reference to basic science removed,
and the essentials of the clinical examination presented. In addition,
novel to medical books as far as I am aware, there are appendices (a
“Toolkit”) that contain some commonly used and handy instruments and
forms that are often useful in the examination of the neurologic
patient, especially in regard to neuroophthalmology. These include: a
simple red lens for diplopia testing, a multi-pinhole for assessing
visual acuity, pocket vision screeners for examining near visual acuity
at near and at a distance of about 6 feet, a primitive but usable
version of an OKN tape, 4 red squares with dots to assess color vision
in all 4 quadrants, selected color vision plates, an Amsler grid for
evaluating central scotomas, a copy of the Blessed memory-orientation
questionnaire, and copies of the Glasgow coma scale, the Hunt and Hess
scale for evaluating subarachnoid hemorrhage patients, and a diagram of
the brachial plexus. Commercial interests would not allow the inclusion
of the Folstein mini-mental examination.
The hope is that the Toolkit will elevate the Pocket Guide from a mere abbreviated textbook on the neurologic examination to a useful clinical tool for examining patients. With the Pocket Guide
and its accompanying Tools, along with the usual instruments found in
the neurologist’s black bag, the examiner should find at hand all the
reasonable tools with which to do a complete neurologic examination, to
include detailed neuro-ophthalmologic assessment.
The larger textbook, DeJong’s The Neurologic Examination, remains the definitive source for all aspects, common and abstruse, for a discussion of the examination. The Pocket Guide
is intended as a brief version, pocket or bag portable, that contains
the essentials of the examination as well as many of the tools that are
often hard to find when needed most.


Pathologic processes behave in certain ways depending on
their location in the nervous system, and in certain other ways related
to their inherent natures. Neurologists deal in two basic clinical
exercises: where is the lesion in the nervous system and what is the
lesion in the nervous system: differential diagnosis by location and
differential diagnosis by pathophysiology or etiology. The anatomic
diagnosis and the etiologic diagnosis aid and support each other. In
general, the neurologic examination aids primarily in establishing the
anatomic or localization diagnosis and the history aids in the
etiologic diagnosis, but there is overlap. The examination also serves
to indicate the severity of the abnormality. A dependence on
neuro-imaging and other tests as the primary approach to diagnosis
causes many errors. Defining the patient’s illness first in terms of
anatomy and likely etiology helps insure the appropriate use of
neurodiagnostic studies.
The first consideration should be whether the patient
has an organic disease or whether the symptoms are likely psychogenic.
If the disorder is organic, consider whether the condition is a primary
neurologic disease, a neurologic complication of a systemic disorder, a
neurologic complication of drug or medication use, or the effects of a
The patterns of abnormality found on examination help to
localize a disease process to a particular part of the nervous system.
Clinical features that are particularly helpful in neurologic
differential diagnosis include the distribution of any weakness, the
presence or absence of sensory symptoms, the presence or absence of
pain, the presence or absence of cranial nerve abnormalities and
whether they are ipsilateral or contralateral to the other
abnormalities on examination, the status of the reflexes, the presence
of pathological reflexes, involvement of bowel and bladder function,
and the presence or absence of symptoms that clearly indicate cortical
involvement. Weakness may be unilateral or bilateral, symmetric or
asymmetric, primarily proximal or primarily distal; each of these
patterns has differential diagnostic significance. The pattern of
sensory abnormalities also provides significant information.
In trying to make an anatomical localization, it may be
helpful to organize the nervous system by considering sequentially more
peripheral or central structures, beginning either at the cerebral
cortex or the muscle. Consider each level where disease tends to have a
characteristic and reproducible clinical profile. For example, disease
involving the muscle, neuromuscular junction, peripheral nervous
system, nerve roots, spinal cord, brainstem, and hemispheres each tend
to produce a characteristic clinical picture. Some diseases cause
multifocal or diffuse abnormalities, and these are often particularly
At each major level, disease processes tend to have
characteristic clinical features, although with some degree of overlap.
By trying to localize the disease process to one or two likely levels,
such as muscle or neuromuscular junction, one can then think more
systematically about the etiologic possibilities.
Common muscle diseases include muscular dystrophies and
inflammatory, metabolic, toxic, and congenital myopathies. Patients
with muscle disease usually have symmetric, proximal weakness. Deep
tendon reflexes (DTRs) are usually intact but may be depressed when
weakness is severe. There are no pathological reflexes. Patients may or
may not have muscle pain, tenderness or soreness; usually they do not.
There is no sensory loss; bowel and bladder dysfunction generally do
not occur, there are no defects in coordination, mentation, or higher
cortical function.
NMJ diseases include myasthenia gravis (MG),
Lambert-Eaton syndrome, botulism, hypermagnesemia, and others. The most
common condition by far is MG. Patients with NMJ disorders usually


symmetric, proximal muscle weakness, which can simulate a myopathy, but
in addition often have bulbar involvement. Most commonly patients have
weakness of eye movement causing double vision, or ptosis of one or
both eyelids. They may have trouble talking and swallowing, with a
tendency to nasal regurgitation of fluids. Such symptoms and signs of
bulbar weakness are one of the main differences between an NMJ disease
and a myopathy. There is no pain or sensory loss. DTRs are normal in MG
but may be depressed in Lambert-Eaton syndrome and other presynaptic
disorders. There are no pathological reflexes.

Common causes of peripheral neuropathy include diabetes
mellitus, alcoholism, and GBS. Most patients with polyneuropathy have
symmetric, predominantly distal weakness, sensory loss, depressed or
absent DTRs, no pathologic reflexes, and no bowel or bladder
dysfunction. Pain is a common accompaniment and often a major clinical
feature. Proximal weakness can occur with some neuropathies.
Diseases involving the brachial plexus are much more
common than those involving the lumbosacral plexus. Most brachial
plexopathies are due to trauma. Neuralgic amyotrophy (brachial
plexitis, Parsonage-Turner syndrome) is a common inflammatory disorder
of the brachial plexus that is notoriously painful. Patients with
plexus disorders have a clinical deficit which mirrors the involved
structures, so a knowledge of plexus anatomy is vital to deciphering
the deficit. There is typically both weakness and sensory loss,
accompanied by depressed or absent DTRs in the involved area, no
pathologic reflexes, and no bowel or bladder dysfunction.
Most radiculopathies are due to disc herniations or
spondylosis. When severe, there are both motor and sensory deficits and
a depressed DTR in the distribution of the involved root(s). Pain is
common and often severe, usually accompanied limitation of motion of
either the neck or lower back, along with signs of root irritability,
such as a positive straight leg raising test. There are no pathological
reflexes, and no bowel or bladder dysfunction. The presence of these
findings suggests there is concomitant spinal cord compression.
Common causes of myelopathy include compression, trauma,
and acute transverse myelitis. With transverse myelopathy, there is
symmetric involvement causing bilateral weakness below a particular
level, producing either paraparesis or quadriparesis. In addition to
weakness below the level of the lesion, patients with spinal cord
lesions may also have paresthesias, numbness, tingling, and sensory
loss with a discrete sensory level, usually on the trunk. Except during
the acute phase, patients with spinal cord disease tend to have
increased reflexes, along with pathologic reflexes such as the Babinski
sign. Patients with spinal cord disease also tend to have difficulty
with sphincter control, and bladder dysfunction is often an early and
prominent symptom. Pain is not a common feature except for local
discomfort due to a vertebral lesion. Peripheral neuropathy may also
cause symmetric motor and sensory loss, but DTRs are decreased,
sphincter dysfunction is very rare, and there is often pain.
The classic distinguishing feature of brainstem
pathology is that deficits are “crossed,” with cranial nerve
dysfunction on one side and a motor or sensory deficit on the opposite
side. There are often symptoms reflecting dysfunction of other
posterior fossa structures, such as vertigo, ataxia, dysphagia, nausea
and vomiting, and abnormal eye movements. Unless the process has


reticular activating system, patients are normal mentally, awake,
alert, able to converse (though perhaps dysarthric), not confused, and
not aphasic. DTRs are usually hyperactive with accompanying pathologic
reflexes in the involved extremities; pain is rare and sphincter
dysfunction occurs only if there is bilateral involvement.

Disease may selectively involve one, or occasionally
more than one, cranial nerve. The long tract abnormalities, vertigo,
ataxia, and similar symptoms and findings that are otherwise
characteristic of intrinsic brainstem disease are lacking. Common
cranial neuropathies include optic neuropathy due to multiple
sclerosis, third nerve palsy due to aneurysm, and Bell palsy.
Involvement of more than one nerve occurs in conditions such as Lyme
disease, sarcoidosis, and lesions involving the cavernous sinus.
Patients with cerebellar dysfunction suffer from various
combinations of tremor, incoordination, difficulty walking, dysarthria
and nystagmus, depending on the parts of the cerebellum involved. There
is no weakness, sensory loss, pain, hyperreflexia, pathologic reflexes,
sphincter dyscontrol, or abnormalities of higher cortical function.
When cerebellar abnormalities result from dysfunction of the cerebellar
connections in the brainstem there are usually other brainstem signs.
Diseases of the basal ganglia cause movement disorders
such as Parkinson disease or Huntington chorea. Movement disorders may
be hypokinetic or hyperkinetic, referring to whether movement is in
general decreased or increased. Parkinson disease causes bradykinesia
and rigidity. Huntington disease in contrast causes increased movements
that are involuntary and beyond the patient’s control (chorea). Tremor
is a frequent accompaniment of basal ganglia disease.
Characteristic of unilateral hemispheric pathology is a
“hemi” deficit: hemisensory loss, hemiparesis, hemi-anopsia, or perhaps
hemiseizures. Other common manifestations include hyperreflexia and
pathologic reflexes. Pain is not a feature unless the thalamus is
involved, and there is no difficulty with sphincter control unless both
hemispheres are involved. Within this framework, disease affecting the
cerebral cortex behaves differently from disease of subcortical
structures. Patients with cortical involvement may have aphasia,
apraxia, astereognosis, impaired two point discrimination, memory loss,
cognitive defects, focal seizures, or other abnormalities that reflect
the essential integrative role of the cortex. Processes affecting the
dominant hemisphere often cause language dysfunction in the form of
aphasia, alexia, or agraphia. With disease of the non-dominant
hemisphere, the patient may have higher cortical function disturbances
involving functions other than language, such as apraxia. If the
disease affects subcortical structures, the clinical picture includes
the hemidistribution of dysfunction but lacks those elements that are
typically cortical, e.g., language disturbance, apraxia, seizures,
Some disease processes are diffuse or multifocal,
producing dysfunction at more than one location, or involve a “system.”
For example, Devic disease characteristically affects both the spinal
cord and the optic nerves, i.e., it is multifocal. ALS is a system
disorder causing diffuse dysfunction of the entire motor system from
the spinal cord to the cerebral cortex, sparing sensation and higher
cortical function.


From a differential diagnostic standpoint, it is usually
most helpful to think first about the localization of the disease
process in the nervous system, and secondarily about the etiology.
Localization limits the etiologic differential diagnosis, since certain
disease processes typically involve or spare particular structures.
Knowing the likely location of the pathology generally places the
condition into a broad etiologic differential diagnostic category.
Occasionally, the etiology is very obvious, such as stroke or CNS
trauma and the diagnostic exercise focuses mostly on the localization.
Some of the etiologies of primary neurologic disease include neoplasms,
vascular disease, infection, inflammation, autoimmune disorders,
trauma, toxins, substance abuse, metabolic disorders, demyelinating
disease, congenital abnormalities, migraine, epilepsy, genetic and
degenerative conditions. Neurologic complications of systemic disease
are very common.
Psychiatric disease as an etiologic category requires a
caveat. The psychiatric disorders most often of neurologic concern are
depression, hysteria, malingering, and hypochondriasis. These are also
frequently referred to as functional or nonorganic disorders.
Depression tends to exaggerate any symptomatology, neurologic or
otherwise. The diagnosis of nonorganic disease can be treacherous.
So-called “hysterical signs” on physical examination are often
extremely misleading.

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