Carl Wernicke of the Wernicke Area: A Historical Review
Abdullah Ahmad1

, Nitin Jagdhane2

, Karin Ademmer3

, Kishor Choudhari4

INTRODUCTION
Carl Wernicke (1848e1905), a neurologist,
neurosurgeon, and psychiatrist, is
renowned for his field-defining work on
aphasia with his first publication in 1874,

Der Aphasische Symptomencomplex: eine psy-
chologische Studie auf anatomischer Basis (“The

Aphasia Symptom-Complex: A Psycho-
logical Study on an Anatomic Basis”) as

seen in Figure 1.

1 He was just 26 years old
then, but his work gained him instant
fame in the field. However, his
contributions to modern medicine go
beyond his work on aphasia. These
contributions are often not adequately
recognized and we attempt to highlight
them in this article. In the 19th century,
Wernicke played a key role in the
development of anatomy, neurology,
neurosurgery, and psychiatry as we
understand them today. His data-driven
approach using the latest neuroanatomy

and neurophysiology to derive novel in-
sights into the human body has made him

a revolutionary figure in the neurosci-
ences. In subsequent sections, we sum-
marize his life story to provide a brief

account of his inspiring journey and
achievements in the medical field.
THE LIFE HISTORY OF CARL WERNICKE
Carl Wernicke was born on May 15, 1848,
in Tarnowitz, a village in the historical
region of Silesia, which belonged to
Prussia and then the German Empire
during his lifetime, but in the modern day
is part of Poland.2 From a family of
modest means, he was well supported by
his mother, who strongly believed in
education, resulting in his schooling at
the academies of Oppeln and Breslau,
the major cities of the region. After
Wernicke’s father died, his mother
encouraged him to study at the
University of Breslau, which was at the
time, the capital of the region and its
largest city (now Wrocław in Poland).
She too passed away after her son’s state
examinations for medical school.
However, she ensured that she had
secured the funds needed to support him
during his time at university.
Completing medical school in 1870,
Wernicke is noted to have enjoyed his
studies and had garnered a reputation for
being a good fellow among the faculty and
colleagues (Figure 2). As is not

uncommon, he was unsure of which
specialty to choose after graduation.
Having great respect for the work and
character of Dr Foerster, the resident
ophthalmologist, he undertook a 6-

month assistantship with him. This asso-
ciation guaranteed him Foerster’s friend-
ship, which would serve him well in future

endeavors. The subsequent Franco-
Prussian War of 1870 provided Wernicke

with exposure to surgery and made him
consider becoming a surgeon, as well.

After the war, he took part in an assis-
tantship at the Psychiatric Institute of the

Allerheiligen Hospital under Heinrich
Neumann (1814e1888). During this
tenure, he also had an opportunity to work
for 6 months in Vienna under Theodor
Meynert (1833e1892), who was then
considered the founder of comparative
anatomy of the nervous system.3
This period exposed Wernicke to many
luminaries of the day, many of whom he
would call friends, and provided him with
experiences that greatly affected his
career. In particular, his experience in
Vienna in 1874 seemed to have resonated
with Wernicke. He would later often state
how Meynert had affected his career and
credited Meynert for his initial discoveries
in aphasia.4 Through this leading figure in
neuroanatomy, Wernicke developed his
love for the field and was exposed to the
conundrum of aphasia. In the same year,
The Wernicke area, also known as Brodmann area 22, is located in the posterior

segment of the superior temporal gyrus in the dominant hemisphere. Carl Wer-
nicke, a German neurologist, described this area in 1874. The life story of Carl

Wernicke, a 19th-century medical genius, remains an inspiration for all neuro-
scientists even a hundred years later. We outline Wernicke’s life story and

academic achievements in neurosurgery, neurology, and psychiatry. We explore
his remarkable ability to turn his many setbacks into steps forward, his
controversial foray into psychiatry, and his wide-ranging set of contributions,

including his work on external ventricular drainage for hydrocephalus and en-
cephalopathy; his description of the eponymous Wernicke area; and his field-
defining work on aphasia. This historical review attempts to bring to life a

seminal figure in the neurosciences, providing an insight into his visionary
thought process.

Key words
- Aphasia
- Carl Wernicke
- Hydrocephalus
- Sensory aphasia
- Speech area of brain
- Superior temporal gyrus
- Wernicke area
From the 1
School of Medicine and Population Health,
University of Sheffield, Sheffield, United Kingdom; 2
Dr. D Y
Patil Medical College and Hospital, Navi Mumbai, India;
3
Department of Psychiatry and Psychosomatics, Varisano
Hospital, Frankfurt-Main-Taunus-Hospital Group, Hofheim am
Taunus, Germany; and 4

Neurosurgery Department, Sheffield
Teaching Hospitals NHS Foundation Trust, Royal Hallamshire
Hospital, Sheffield, United Kingdom.
To whom correspondence should be addressed:
Abdullah Ahmad.
[E-mail: <PRESIDIO_ANONYMIZED_EMAIL_ADDRESS>]
Citation: World Neurosurg. (2024) 185:225-233.
https://doi.org/10.1016/j.wneu.2024.02.103

Journal homepage: www.journals.elsevier.com/world-
neurosurgery

Available online: www.sciencedirect.com
1878-8750/a 2024 The Author(s). Published by Elsevier Inc.
This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/).

WORLD NEUROSURGERY 185: 225-233, MAY 2024 www.journals.elsevier.com/world-neurosurgery 225
Historical Vignette

he penned his field-changing first publi-
cation on aphasia, at the age of 26 years.

This publication gained him a reputation

that helped him secure an assistantship
with Carl Westphal (1833e1890), a leading
psychiatrist at the Berlin Charité Hospital,

a premier institute for health care in Ger-
many in 1875 and up to the modern day.

Dispute with Medical Administration in
Berlin
Wernicke’s time in Berlin had started

well but a dispute with the local man-
agement almost ended his career. By

1876, he had completed his ”Habilita-
tion,” granting him junior membership

of the medical faculty and permission to
charge lecture fees. He was hailed as a
rising star and had great expectations;
however, an event occurred that almost
cost him his career. Although details are
scarce, an argument with the hospital
administration in March 1878 regarding
personal matters escalated to the extent
that not only was his assistantship
terminated but Althoff, the ministerial
director during his time, who held
powers of veto in the medical faculty,

ensured that Wernicke would never re-
turn to Berlin again for work. Consid-
ering Berlin’s leading position for

research in Germany, it seemed that
Wernicke’s career was coming to an

early end. However, arguably, this inci-
dent had the opposite effect. In response

to this devastating turn of affairs, Wer-
nicke instead took advantage of the free

time he now had to socialize with friends
and pursue his passion for scientific
writing. Publications during this time
cemented his position as an authority in
neurology and equally his interest in
psychiatry.
Resurrection of Career at Breslau
In 1885, Wernicke returned to a formal
academic life at the University of Breslau
with the support of his old friend, the
ophthalmologist Foerster. In 5 years, he
became chairman of the Department of
Neurology and Psychiatry after the death

of his first mentor, Neumann. Wer-
nicke’s tenure saw him switch to a more

psychiatric focus, using his data-driven
approach derived from neurohistology

and neurosurgery to test his own hy-
potheses on psychiatric disorders. It

provided him with the first opportunity
in many years to have the resources

required to carry out studies of psychi-
atric and focal neurologic symptoms,

along with many students and assistants
who now rank as key contributors to the
medical field. Some of the noted names

Figure 1. Book cover of Der Aphasische Symptomencomplex: eine psychologische Studie auf
anatomischer Basis (“The Aphasia Symptom-Complex: A Psychological Study on an Anatomic
Basis”) by Carl Wernicke in 1874. Reproduced under the Public Domain Mark licence from the King’s
College London, Foyle Special Collections Library.

226 www.SCIENCEDIRECT.com WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2024.02.103
HISTORICAL VIGNETTE
ABDULLAH AHMAD ET AL. CARL WERNICKE OF WERNICKE AREA

include Heinrich Lissauer (1861e1891)
for his work on agnosia and Carl Kleist

(1879e1960) for his work on psychopa-
thology, having created the terms uni-
polar depression (now major depressive

disorder) and bipolar disorder.5 In
addition to his academic excellence,
Wernicke was also accomplished in his
personal life, with his biography stating
that “after the day’s work he could
often be seen going out into the
countryside with a child on each hand,”
with 3 children (2 daughters and a son)
and a loving wife.2

Rise, Fall, and Rise Again

When asked about his goals in life, Wer-
nicke is reported to have said to his stu-
dent Kleist during a hiking trip in the

Glatzer mountains, “There is only one
proper motive in work and that is.“Seek
ye first the kingdom of God and all the rest shall
follow.’”2 After almost 20 years, the funding
for Wernicke’s department was curtailed.
This development encouraged him to
pursue his research ambitions at a larger
university. He applied to 3 locations
(Vienna, Berlin, and Munich) without
success. Vienna failed because of false

rumors of his refusal being circulated in
the media; Berlin was stopped by his
adversary Althoff; and his other
adversary, Emil Kraepelin (1856e1926),
received the position in Munich instead
of him. This situation resulted in
Wernicke’s having no university
affiliation again for 1 year, with the
returned fear of his career ending
abruptly. Once again, Wernicke turned a
misfortune into an opportunity by using
this time to work on his most famous
psychiatric publication, Grundriss der
Psychiatrie (“Foundations of Psychiatry”).
Although his affiliation was restored after
a year, his dissatisfaction with the
institution led him to accept an offer
from the University of Halle to lead their
Clinic of Psychiatry and Neurology.
Wernicke in Halle
Wernicke’s brief 1-year tenure at Halle
began in 1904 and held great promise on
both an academic and personal level. At
the age of 57 years, he was noted as being
‘“more mellow”’ and happier with the

opportunities on offer at Halle by his as-
sistant Kleist.2 Wernicke’s continued skill

at managing workelife balance meant
that at this stage in his career, he not only
was held in high esteem by the academic

world, with exciting new research plan-
ned, but had also cultivated a close circle

of friends, a loving family, and a set of
active hobbies ranging from gymnastics
and mountain climbing to cycling. Cycling

is especially pertinent because he experi-
enced a fatal accident while on a cycling

trip in Thuringer forest. A cart ran over
him, leaving him with injuries; although
nowadays such injuries are manageable, at
the time, they meant 2 days of severe pain,
ending with his death on June 15, 1905.
From the numerous obituaries, it was clear
that a man who was both loved and
respected had passed from the research
community and that his work would be
recognized as withstanding the test of
time.6
To us, his last assistants, remains
the memory of renowned yet

modest man, a model who entrus-
ted us with far-reaching confidence

and independence, a teacher who

discovered in each a certain tal-
ent. To have been his students

Figure 2. A portrait of Carl Wernicke. Reproduced under the Public Domain Mark licence from the
University of Wrocław, Wrocław University Museum Special Collections Library.

WORLD NEUROSURGERY 185: 225-233, MAY 2024 www.journals.elsevier.com/world-neurosurgery 227
HISTORICAL VIGNETTE
ABDULLAH AHMAD ET AL. CARL WERNICKE OF WERNICKE AREA

shall remain our pride as long as we
livee Kleist’s eulogy2
APHASIA BEFORE CARL WERNICKE

Aphasia, defined as a language impair-
ment with a clear and distinctive set of

descriptive clinical features, was first
clearly described in the 17th century by
Schmidt and Rommel, although

appreciation of this condition has been
present at least since the ancient Greeks.7
Respected writers such as Samuel Johnson
and Johann Wolfgang von Goethe describe
it in their writings, showing its
recognition among the public in the 18th
and 19th centuries. From the etiologic
perspective, early understanding of
language impairment revolved around
either a “paralysis of the tongue” or the

predominant theory of brain function
localization in the ventricles.8 The most
popular conceptualization was that of
Albert Magnus (1200e1280) as seen in
Figure 3, in which each of the 3
ventricles broadly corresponds to
perception, reason, and memory9
(Figure 3).
Progress on understanding the cause
behind aphasia was arguably slowed at an
intellectual level by René Descartes (1596e
1650) and his theory of mindebody

dualism, because it popularized a separa-
tion between the organic body (the brain)

and the inorganic mind, which in this
context meant language.10 Called holism
as opposed to localization, this approach
was the undisputed status quo until
Franz Joseph Gall (1758e1828) defended
his work on phrenology in public debate,
breaking the taboo that had developed
around discussing the possibility of a
connection between the brain and the
mind. Jean-Baptiste Bouillaud (1796e
1881), Gall’s student, carried on his work
in localization and taught Paul Broca
(1824e1880), who became a recognized
figure in the field and after whom the

Broca area is named. Broca helped pro-
mote the theory of localization and

famously debated with Trousseau in 1864
in the Académie de Médicine, Paris, when

Trousseau disproved Broca’s conceptuali-
zation of a sole language center by

comparing patient autopsies and verifying
if lesions would be found in the relevant
section. This debate advanced the term
“aphasia” as a general word for language
disturbances but showed that the
conceptualization of the Broca area as the
sole area responsible for speech was
incorrect.
The localization of language function in
the brain was the key debate of the century
into which Carl Wernicke was born and he
played a significant role in shaping it. He
later credited the work of Broca as having
played a key role in helping develop his
thoughts on the field.
WERNICKE AND HIS WORK ON APHASIA
Carl Wernicke applied the neuroanatomic
approach developed in his time with

Meynert with the conceptualization of lo-
calizations championed by Broca and

Eduard Hitzig (1838e1907) to lay out a
field-defining approach to aphasia.10 At

Figure 3. A woodcut of Albert Magnus’ conceptualization of ventricles titled De anima made in 1506.
From left to right, each ventricle corresponds to a specific brain function: I, common sensory input
and imagination; II, rational thought, evaluation, and creativity; and III, memory and motion.7,8
Reproduced under the Public Domain Mark licence from the Wellcome Collection, Philosophia
Naturalis by Albertus Magnus.

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HISTORICAL VIGNETTE
ABDULLAH AHMAD ET AL. CARL WERNICKE OF WERNICKE AREA

the age of 26 years in 1874, after his
assistantship in Vienna, Carl Wernicke
published his first and career-defining

book titled Der Aphasische Symptomencom-
plex: eine psychologische Studie auf anatomischer

Basis (“The Aphasia Symptom-Complex: A

Psychological Study on an Anatomic Ba-
sis”). Precise neuroanatomic description

of his aphasia model and the theory of
memory imagery is outside the scope of

this section; however, the book is recog-
nized as a classic in aphasiology. The

study laid out the first description of a
novel sensory speech center, sensory
aphasia, and a schema to understand
aphasia.2 Over the next 2 years, Wernicke
further elaborated points of his schema,
cementing his position, such as in his
1875 study Das Urwindungsystem des
menschelichen Gehirns (“The Primordial
Gyral-System of the Human Brain”), an
in-depth comparative neuroanatomic
study building on descriptions laid out in
his first work, detailing the sensory speech

center, which he called the “first primor-
dial gyrus,” a unit in the parietal region in

the superior temporal gyrus involved in
speech, which is known as the Wernicke
area. Subsequently, Wernicke went on to
update and develop this model throughout
his life with the monograph Recent Works on
Aphasia in 1885 and the posthumously
published Deutsche-KlinikeAphasia Symptom
Complex in 1906 finalizing his contributions
to the field.2
Wernicke’s Contributions to Defining
Types of Aphasia
The schema involved a 2-point diagram
known as the Wernicke arc, as shown in
Figure 4.
11 This schema formed the basis
of predicting speech and language
disorders using precise anatomic
locations, with the 2 points being an
auditory center known as the Wernicke
area and a motor area for speech
formation known as the Broca area.
Wernicke had not only discovered the
brain area named after him but also
developed an understanding of the Broca
area.10 This arc was relevant in
predicting the impact of lesions. If the
lesion was present at the Wernicke area,
it caused sensory aphasia (the loss of
sound images), resulting in loss of
speech comprehension from others and

Figure 4. The Wernicke arc taken from Der Aphasische Symptomencomplex: eine psychologische
Studie auf anatomischer Basis (“The Aphasia Symptom-Complex: A Psychological Study on an
Anatomic Basis”) by Carl Wernicke in 1874. C, central sulcus; F, frontal lobe; O, occipital lobe; S,
sylvian fissure; T, temporal lobe. Wernicke mentions a “gyral convolution” around the fissure and a is
the terminus of the acoustic nerve. This area is known as the Wernicke area, whereas b is known as
the Broca area. The 2-point Wernicke arc connects a to b using associative fibers. This model is used
in subsequent sections to explain aphasia. Reproduced under the Public Domain Mark licence from
the King’s College London, Foyle Special Collections Library.

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HISTORICAL VIGNETTE
ABDULLAH AHMAD ET AL. CARL WERNICKE OF WERNICKE AREA

the self. If the lesion was in the Broca area,
it led to motor aphasia (loss of articulated
speech). If the lesion was between the 2
centers, in the associative fiber pathway
as described by Meynert (1867), it led to
conduction aphasia, in which
comprehension was present but
inappropriate use of words was also
present.3 If the lesion was present at
both the Broca and Wernicke areas, total
aphasia would be present.1 Wernicke
himself described it as a psychic reflex
arc and used it as a model for psychiatric
conditions, as discussed elsewhere.3
Wernicke based his theory of language
on 3 main points: the cerebral cortex being
the organ of consciousness, specific parts
of the brain holding particular significance
such as the Broca and Wernicke areas, and

associative fibers connecting and coac-
tivating all layers.10 On analysis,

Wernicke’s approach was balanced with
elements of holism through his
abstraction of the higher parts of the
psychophysiologic process required for
communication in the cortex along with
localization and provided the basis for
the connectionist approach that would
become popular in the late 20th century.2

Conceptualization of speech and lan-
guage disease using the Wernicke arc still

dominates the field. Wernicke had helped
mainstream the theory of localization to
explain aphasia and had made it broadly

acceptable, although it still had its de-
tractors. His approach to aphasia is

referred to as the Breslau-Halle school.12
This approach was recognized and
adopted by the international community
during his lifetime, showing the decisive
impact of his work on aphasia in the
field and cementing Germany as the
leading country for aphasia work.2
WERNICKE AND FREUD ON APHASIA

Of the many critiques generated by Wer-
nicke’s work on aphasia, arguably the

most impactful on the medical field was
the 1891 Zur Auffassung der Aphasien: Eine
kritische Studie (“On the Understanding of

Aphasia: A Critical Study”) by the neurol-
ogist and father of psychoanalytic psy-
chology, Sigmund Freud (1856e1939).

This was Freud’s first book as a sole
author and is recognized as a turning
point in his career.13 He attacked
Wernicke’s conceptualization of aphasia

as an organic disease by calling him a
“diagram maker,” asserting that
Wernicke’s approach did not have a
factual basis.14 Freud recognized only
asymbolic, verbal, and agnostic aphasia
and proposed an alternative theory using
mental associations between words and
memory images of objects. Freud’s works
revolved around a psychological cause of
aphasia as opposed to the biological
memory images being localized in an
observable neuroanatomic framework as
promoted by Wernicke.15

The impact of this critique was signifi-
cant, not only because of its focus on

aphasia but also because of its opposition
to the broader movement of biological
psychiatry. It led Freud to switch from
neuroanatomy to pursue studies that
resulted in him founding psychoanalytic

psychology, which was also used to inter-
pret language disorders.15,16

WERNICKE AND HIS OTHER
CONTRIBUTIONS TO NEUROLOGY AND
NEUROSURGERY
Carl Wernicke was prolific in his writing
in neurology; Table 1 lists his eponyms.17
We have highlighted some of his
important contributions in subsequent
sections.
Wernicke Encephalopathy
In 1881e1882, Carl Wernicke published

the Lehrbuch der Gehirnkrankheiten (“Text-
book of Brain Disease”), for which he

became most well known in his time
because it remained the leading textbook

in the field until Von Monakow’s work in

the 1890s. Across 3 volumes, it authorita-
tively laid out brain pathophysiology and

disease classification using a localization
approach. This approach was crucial for
the field because the latest research such
as that by Meynert was noted as being too
“brief” and “obscure” for most researchers
to benefit from.2 It outlined what is now
known as Wernicke encephalopathy. A
follow-up to this work was arguably his
Atlas des Gehirns (“Atlas of the Brain”) from

1897e1903, which was the first photo-
graphic review of the human brain, mainly

organized by his assistants.
Wernicke Hemiplegia, Wernicke Pupillary
Reactions, and Cortical Deafness

In 1883, Carl Wernicke published a trans-
lation of the then recently deceased French

neurologist Guillaume-Benjamin-Amand

Duchenne’s research on movement phys-
iology, which is noted to have been a

possible inspiration for Wernicke’s later
work on residual hemiplegia.2 With the
support of Friedlander, Wernicke also
published the first detailed study of
cortical deafness.
In 1893, one of his final works was the
Gesammelte Aufsätze und kritische Referate zur

Pathologie die Nervensystems (“Collected Es-
says and Critical Reviews in Neuropa-
thology”). It contained a variety of studies,

from reprints and new essays in neuro-
anatomy to critiques of contemporary

research. The most important of these
studies was a description of Wernicke
encephalopathy and Wernicke-Mann
hemiplegia, the tracing of the pyramidal

Table 1. List of Eponyms Associated with Carl Wernicke17
Eponym Description
Wernicke area An area of the brain involved in speech
Wernicke aphasia A term used for classic receptive aphasia
Wernicke encephalopathy The appearance of ocular, cerebellar, neurologic, and memory loss as a

result of thiamine deficiency

Wernicke pupillary reaction The absence of pupillary reflex to light in the blind portion of the retina
Wernicke-Korsakoff syndrome The combined presence of Wernicke encephalopathy and

Korsakoff syndrome
Wernicke-Mann hemiplegia A type of partial hemiplegia of the extremities
Wernicke cramp A psychogenic muscle cramp caused by anxiety or fear
Wernicke dementia A historic term for dementia

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HISTORICAL VIGNETTE
ABDULLAH AHMAD ET AL. CARL WERNICKE OF WERNICKE AREA

tract to the spinal cord, and a study of

what is now known as the Wernicke pu-
pillary reactions.18

Wernicke’s Contributions to the Treatment
of Hydrocephalus
In neurosurgery, Carl Wernicke mainly

contributed to the treatment of hydro-
cephalus.19 In 1881, he carried out the first

documented ventricular puncture using
aseptic techniques in an operation
involving puncturing the trigone with a
trocar using a lateral approach. In
addition, he also was the first to
popularize external ventricular drainage
by leaving a left ventricular cannula in
place.
WERNICKE AND HIS CONTRIBUTIONS TO
AND CONTROVERSIES IN PSYCHIATRY
Carl Wernicke was exposed to psychiatry
early in his career and went on to become
a key figure in the biological psychiatry
movement by pioneering a novel nosology

centered around a systematic neurobio-
logical basis for mental disorders.20 This

nosology followed in the tradition of
previous aphasiologists such as Gall
(1758e1828) and Broca, who promoted
the concept of the cerebral cortex being
the site of mental processes and motor
aphasia, respectively.3 Because aphasia
was generally considered to be at the
intersection of the mind and body, Gall
and Broca also went on to become key
contributors to the biological psychiatry
movement. As recognized by Wernicke’s
contemporary Heilbronner (1905), the
monograph of his titular work on
aphasia held the subtitle of “a
psychological study on an anatomic
basis.” This subtitle was a clear
indication of Wernicke’s
conceptualization of aphasia as a
psychological disorder with an anatomic
basis, with its mechanism forming the
basis for his later works.3
Wernicke’s biological approach made
him an adversary of Emil Kraepelin (1856e
1926), whose methodology inspired the
contemporary International Classification
of Diseases and Diagnostic Statistics
Manual approach to psychiatric
nosology.5,21,22 Wernicke was also
critiqued by contemporaries such as the

prominent psychopathologist Karl Jasper
(1883e1969), who called him a “brain
mythologiser,” claiming that he was
inappropriately extrapolating his aphasia
model to the entire field of psychiatry.3,16
Jaspers likened Wernicke to Freud,
claiming that both individuals used few
facts to produce sweeping generalizations
and abstract models.
Forays into Psychiatric NosologyeThe
Theory of Elementary Symptoms and
Sejunction
No known works have survived that
explicate how Carl Wernicke formulated
his psychiatric approach beyond writings
on consciousness in 1879 and on the
relationship of aphasia to mental illness in
1890. However, conference proceedings
show that he had developed his beliefs in
2 stages: the theory of an “elementary

symptom” and then his “sejunction” the-
ory, which became infamous and was the

subject of criticism.23
His first conceptualization was of the
“elementary symptom,” in which every
psychiatric disorder had a key underlying
symptom that “forms the basis of all other
symptoms” and could be targeted. In
practice, he used anxiety as the elementary
symptom for most disorders and had never
produced a repeatable methodology of how
to investigate and decide on the elementary
symptom of a presentation, making its
usefulness etiologically limited. The key
difficulty in understanding this approach is
his lack of formal writings on this theory
beyond clinical vignettes.23 However, that
situation may be a result of his decision to
pursue the formal realization of his
approach to aphasia onto other psychiatric
disorders instead of further developing
this approach. The “elementary symptom”
theory may have been inspired by his
initial experience in psychiatry under
Neumann as his teacher, who was a
leading proponent of the concept of
“‘unitary psychosis,” the assumption that
all forms of psychosis were different
stages of 1 disease with a single
underlying cause: Wahnsinn (madness).24
Wernicke’s second conceptualization
was centered around the concept of
sejunction. In 1899e1900, he wrote the
Krankenvorstellungen aus der psychiatrischen
Klinik in Breslau (“Clinical Studies from the

Breslau Psychiatric Clinic”), a 3-volume
case review compilation. This material
provided the clinical foundation for his key
text on psychiatry, the Grundriss der Psychiatry
(“Foundations of Psychiatry”), which was
published in 1900.2 The book and its novel
theory of sejunction was controversial, with
notable contemporary Theodor Ziehen
(1862e1950) critically stating that “His
Foundations of Psychiatry is written
almost as if a science of psychiatry did not
yet exist.”
3 Using his characteristic
biologically driven approach to the brain,
Wernicke described psychiatric illness as a
sejunction, a disruption in the connective
pathways of the brain caused by a
lesion.20 It clinically presented itself in 3
ways: a loss of function, hyperfunction, or
a parafunction. This framework was used
to classify a range of different disorders.
For example, in psychomotility, patients
presented with akinesia, hyperkinesias,
and parakinesia (which ranged from
chorea to mannerisms).20
The foundations for this theory were

both the localization approach that Wer-
nicke had developed as an early

researcher and a more developed theory
of memory images, which he had first
described in his titular work on aphasia
in 1874. Originally, the term memory
image was proposed to describe how
sensory information was processed and
stored by the human mind.16 It was a
psychological construct; however,
Wernicke used it to describe both
psychological and sensory information
processed by neural connective
pathways. An example of how this term
was conceptualized is that nervous
excitation for sensory information
manifested as hallucinations, whereas
motor information manifested as
psychomotor agitation. Wernicke’s key
contributions to psychiatry from this
body of work are theoretic to a field

that has recently seen a revival: self-
disorders, a term used to describe fea-
tures of the schizophrenia spectrum.5 His

work helped develop and anticipate
various areas of the field from the
interoceptioneexteroception dichotomy
and abnormal interoception to selfhood,

consciousness, and the modern-day un-
derstanding of self-disorder itself.16,20

Wernicke’s creation of the term

WORLD NEUROSURGERY 185: 225-233, MAY 2024 www.journals.elsevier.com/world-neurosurgery 231
HISTORICAL VIGNETTE
ABDULLAH AHMAD ET AL. CARL WERNICKE OF WERNICKE AREA

“perplexity” to define “the state of mind
in which most mentally ill people
remain while they are still curable” is a
term still in use, although he
understood it in a manner best shown
by the following quote when discussing
his nosology:
If we imagine that it were possible
to rob a healthy person unnoticed of
a large part of the memory images

in which the outside world is re-
flected in him, or to change their

content, we would fully understand
all sorts of wrongs that he
committed in his perplexity.16
Wernicke’s work on psychiatry was a
natural evolution of his work on
neurology. He helped found what is

referred to as the Wernicke-Kleist-
Leonhard school of psychiatry, which

had abandoned his theory of sejunction
but kept his neuroanatomic approach to
psychiatry.20 Some of Wernicke’s

described conditions such as “anxiety-
psychosis,” “motility psychosis,” and

“expansive autopsychosis” were reworked
by students Kleist and then by Karl
Leonhard (1904e1988) into cycloid
psychosis, which has entered into
Kraepelin’s diagnostic classification and
remains to this day.25 Wernicke’s
sejunction theory describes a
connectionist view of the psyche,
arguably anticipating modern neural
networking approaches.
Despite his “Elementary symptom”
theory not being developed further and
having severe flaws, the concept of a key
symptom is still relevant. Although not
considered a part of nosology, it persists
in psychopharmacology in the form of

target symptoms (e.g., the use of anxio-
lytics in patients with acute psychosis).23

Continuing developments in target
symptoms are in keeping with
Wernicke’s earlier tradition.
WERNICKE IN THE 21ST CENTURY
Carl Wernicke is aptly remembered as a
pivotal figure in the neurosciences in the
modern day because of his contributions
to aphasia. At the beginning of the 20th

century, toward the end of Wernicke’s life

and after his death, neurology and psy-
chiatry split into 2 specialties. Although

the localization approach has persisted in
neurology, with behavioral neurologists
and clinical neuropsychologists carrying
on Wernicke’s work, biological psychiatry
has given way to modern psychiatry’s

Kraepelinian symptoms-based classifica-
tion.16 Wernicke’s theory of

connectionism has been vindicated by
contemporary research through the
resurgence of neural networks, which
share similarities. His work inspired
Norman Geschwind (1926e1984) to play
an important role in the development of
behavior neurology and neurolinguistics,
especially in aphasia.15
With the resurgence of neuropsychiatry

and interest in neural networks, Wer-
nicke’s work, although not so well known,

is more relevant than ever before. With the
recent creation of the research domain of

criteria indicating a trend toward biolog-
ical psychiatry, the systematic neuroana-
tomic and connectionist approach

pioneered by the Wernicke-Kleist-
Leonhard school of psychiatry and its

body of work may be worthy of
reappraisal.26
Wernicke was a man described as “Der
Forscher, the exploreretheorist in quest of a
theory of psychic life.”

2 His remarkable
capacity to balance professional and
personal life and maintain remarkable
physical health is a timely reminder that
it is possible to maintain a high standard

of well-being while producing field-
changing work. Despite his interest in

biologically explicating the human mind,
he believed that a person was greater than
the sum of their parts. We would like to
close this homage with a quote from
Wernicke taken from his biography that is
even more pertinent with the advances in
computing:
If man would not be a mere
counting-machine or registrar, he
remains exposed to error. But
should he, therefore, hold the
counting-machine as his ideal? May
that thought hold as little sway in
my riper years, as it has in the past.
(Carl Wernicke in Breslau, 1892)2

CRediT AUTHORSHIP CONTRIBUTION
STATEMENT
Abdullah Ahmad: Writing e original
draft, Investigation. Nitin Jagdhane:

Writing e review & editing. Karin Adem-
mer: Writing e review & editing. Kishor

Choudhari: Writing e review & editing,
Supervision, Conceptualization.
REFERENCES
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Sourcebook and Review - Early Sources in Aphasia and
Related Disorders. Vol 1. Berlin, Boston: De Gruyter
Mouton; 1977.
3. Lanczik M, Keil G. Carl Wernicke’s localization
theory and its significance for the development
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4. Whitaker HA, Etlinger SC. Theodor Meynert’s
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6. Siemerling E. Carl Wernicke. Arch Psychiatr Ner-
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7. Benton AL, Joynt R. Early descriptions of aphasia.
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history in the (Re)birth of behavioral neurology.    1.
Research Aim:
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2.
Hypothesis: 
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3.
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