Background article for impactfeaturespace.com. Narrative history; limits of the evidence are stated in the text and in the evidence notes.
Introduction
Four partly independent systems of naming run through the literature on head injury:
Lesion or mechanism: concussion, contusion, laceration, diffuse axonal injury.
Clinical syndrome: concussion as a transient disturbance of brain function.
Severity grade: mild, moderate, severe, usually based on level of consciousness.
Setting of assessment: sport, emergency department, insurance, court.
One word can belong to different systems in different countries. A 2001 historical review describes the confusion in terminology as dating from antiquity [1]. The 2017 consensus statement on concussion in sport describes continuing confusion in definition and terminology and calls the term mild traumatic brain injury (mTBI) similarly vague in that context [2].
1. Origins: commotio, contusio, compressio
The first clear separate recognition of concussion is credited to the Persian physician Rhazes in the 10th century [1]. Secondary historical sources attribute the separation of cerebral commotion from contusion to Lanfranc and Berengario da Carpi, and credit Ambroise Paré with giving the term commotio currency in the 16th century [3]. The primary texts are Lanfranc's Chirurgia magna (1498) [4], Berengario's treatise on skull fracture (1517) [5] and Paré's collected works (1585) [6]. The English word derives from Latin concutere, "to strike together" [7].
A three-part scheme of commotio, contusio and compressio cerebri is attributed to J. L. Petit in a German university teaching script [8]. His treatise on surgical diseases was published posthumously as Traité des maladies chirurgicales (1774) [9]. The passage has not been located in Petit’s text, so the attribution of the scheme to him rests on the teaching script alone. In this scheme:
Commotio is a transient disturbance of function without a structural lesion.
Contusio is bruising of brain tissue.
Compressio is damage by pressure, for example from haematoma, oedema or a depressed fracture.
The three Latin terms entered German, French and Russian medicine, and their later meanings diverged.
2. 1920s–1970s: time, amnesia and the functional–structural dispute
British tradition. Trotter (1924) [10], Russell (1932) [11] and Symonds and Russell (1943) [12] developed the assessment of closed head injury around duration of amnesia. The cohort came from the Oxford Military Hospital for Head Injuries. Ross (2018) argues that post-traumatic amnesia (PTA) became central to British neurological assessment of blunt head trauma in 1920–40. In his account, concussion was reconceptualised by Trotter as transient loss of consciousness leaving no long-term physiological damage [13]. Russell and Smith (1961) [14] and Symonds (1962) [15] extended this work.
Functional versus organic interpretation. Osnato and Giliberti (1927) [16] and Strauss and Savitsky (1934) [17] argued that post-concussion phenomena reflect tissue injury. Miller's "Accident neurosis" (1961) [18] represented the opposing psychogenic interpretation.
Experimental and pathological work:
Denny-Brown and Russell (1941) [19] studied experimental concussion. A contemporaneous summary distinguishes acceleration concussion, which accompanies closed head injury, from compression concussion [20].
Strich (1956) described diffuse degeneration of cerebral white matter after severe head injury [21].
Gurdjian, Webster and Lissner (1955) examined concussion, contusion and laceration together [22].
At a 1954 meeting Saucier called concussion a misnomer, because closed head injury symptoms appeared identical in concussion, contusion and laceration. He proposed "traumatic encephalopathy" instead [23, 24]. Concussion nevertheless remained the preferred term after the Glasgow Coma Scale (1974) and the 1993 mTBI definition [24].
Spectrum hypothesis. Primate experiments with non-impact angular acceleration produced responses ranging from mild concussion to massive diffuse white matter damage with prolonged coma [25]. Ommaya and Gennarelli (1974) correlated experimental and clinical observations in blunt head injury [26]. Gennarelli and colleagues (1982) linked coronal head motion to diffuse axonal injury and prolonged coma [27], and Adams and colleagues (1982) analysed 45 human cases [28]. Whether concussion lies at the mild end of a structural continuum or is purely functional remains unresolved [1].
3. Grading severity: nomenclature committees and scales
The Congress of Neurological Surgeons committee on head injury nomenclature reported in 1966 [29]. Its definition of concussion, as summarised later, is a clinical syndrome of immediate and transient post-traumatic impairment of neural function, such as altered consciousness or disturbed vision or equilibrium, due to mechanical forces [7].
In 1979 the World Federation of Neurosurgical Societies published a glossary of about 200 terms in English, German, Spanish and French [30]. A Japanese-language review of the glossary (1981) is the only available source for an inter-language difference, and it could not be confirmed from the Glossary itself or from another source. As reported by that review [31]:
In English, Spanish and French usage, concussion may involve neurological deficit of varying degree.
In German usage, a case with neurological deficit is classified as contusion.
The review also notes the German term Durchgangssyndrom and the French entry syndrome subjectif post-traumatique, which had no direct English counterpart.
The current German guidelines [32, 33] describe how commotio and contusio are distinguished in German usage and are the better basis for the German side of this comparison.
The Glasgow Coma Scale (1974) [34] and Glasgow Outcome Scale (1975) [35] standardised severity grading. The division into mild (GCS 13–15), moderate (9–12) and severe (≤8) is the most widely used internationally. The German adult guideline notes reservations about the reliability and validity of GCS-based classification [32]. In Germany about 91% of head injuries are classed as mild, 4% moderate and 5% severe [32]. The WHO task force reports that 70–90% of treated brain injuries are mild [36].
4. "Minor", "mild" and "complicated mild" head injury
The 1970s–80s literature used "minor head injury". Examples are Gronwall and Wrightson on delayed recovery of intellectual function (1974) [37], Rutherford and colleagues on sequelae of concussion (1977) [38], Rimel and colleagues on disability (1981) [39] and Barth and colleagues on neuropsychological sequelae (1983) [40]. Rimel's abstract reports that litigation and compensation had a minimal role in outcome [39]. Wrightson (2000) reviewed how the concept of mild head injury developed [41].
Operational definitions followed:
ACRM 1993. The American Congress of Rehabilitation Medicine committee published the first organised interdisciplinary definition, with four criteria [42, 43].
WHO task force 2004. It retained the four criteria with two modifications. It also found that studies used divergent case definitions: some required neither loss of consciousness nor amnesia, and some excluded imaging abnormalities [43, 44].
WHO criteria as reproduced in the German 2024 guideline [33]:
Loss of consciousness, confusion or disorientation up to 30 minutes.
PTA up to 24 hours.
Transient focal neurological signs, or seizures.
GCS 13–15 at 30 minutes or at first medical contact.
Exclusion of confounding factors.
The guideline notes the 30-minute limit has weak evidence but was retained in the 2023 ACRM update for lack of better graded systems.
Complicated versus uncomplicated mild TBI distinguishes cases with and without intracranial imaging abnormality [45].
ACRM 2023 updated the diagnostic criteria [46]. The label "concussion" may be used interchangeably with mild TBI when neuroimaging is normal or not clinically indicated [47].
5. German-language tradition
Commotio cerebri corresponds to Gehirnerschütterung, and Contusio cerebri to Hirnprellung or Kontusion. Lay and educational web sources use Gehirnquetschung for contusio in some cases [48] and for compressio in others [49]. The 2015 and 2024 guidelines use none of these lay terms.
Forensic origin of the sharp separation. Birkmayer (1952) wrote on commotio as a "pathogenetic and Begutachtung problem" (expert-assessment problem). He concluded that although the transitions between commotio and contusio are fluid pathogenetically, the assessor needs a clear separation, with duration of unconsciousness as the most important criterion [50].
Tönnis and Loew (1953). They proposed three grades based on duration of neurological disturbance [51]. According to the 2015 guideline, the grading can be applied at the earliest after three weeks, so de facto only retrospectively [32]. The 2024 guideline regards the Tönnis–Loew grading as obsolete, because analgosedation largely determines the interval [33].
The 2024 expert-assessment guideline makes several points [33]:
The traditional dichotomy (commotio, with loss of consciousness under 30 minutes and no lasting consequences; contusio, with substantial brain damage) no longer matches current knowledge, because traumatic brain damage occurs without loss of consciousness.
The concept of brain injury with versus without a substantial correlate nevertheless matches the decisive medico-legal question. In German insurance and civil law the first injury (Erstschaden) must be proven to the standard of Vollbeweis (full proof).
mTBI or leichtes SHT is often wrongly used as a synonym for commotio. mTBI is broader and does not exclude substantial brain damage.
Brief or absent loss of consciousness makes substantial brain injury less likely without excluding it (contusio sine commotio).
The guideline recommends reserving Schädel-Hirn-Trauma for cases with at least transient demonstrable brain dysfunction or injury, and calling head injury without brain involvement Schädelprellung. The 2015 guideline gives the same definition [32].
Convulsions beginning within seconds of a concussive blow are termed kommotionelle Konvulsionen or Aufprallanfälle in German-language literature [52]. In 22 elite football cases, they began within 2 seconds of impact, lasted up to 150 seconds, were followed by rapid recovery and left no structural or permanent injury; none developed epilepsy over a mean 3.5 years [53]. They are a clinical example of the transient, functional disturbance that the term Kommotion originally denoted.
Empirical data support the 2024 guideline's statement that the commotio/contusio dichotomy no longer matches current knowledge. In 135 patients with mild TBI, 27% of those with a normal CT had an abnormal early MRI, and contusion or multiple foci of haemorrhagic axonal injury predicted worse 3-month outcome [54]. In a US trauma-centre cohort, 61% of CT-positive and 49% of CT-negative mild TBI patients reported impairment at 12 months [55]. In swine, extensive axonal pathology followed head rotation in both planes, even without sustained loss of consciousness [56]. Using "Kommotion" as shorthand for "transient and benign" is therefore unreliable as an outcome statement.
Current German coding and grading:
ICD-10-GM codes S06.0 as Gehirnerschütterung (commotio cerebri). S06.2- covers diffuse brain injury, including diffuse contusions, and S06.3- covers circumscribed brain injury. S06.7 codes duration of unconsciousness [32].
A clinical reference lists the three Latin terms, equated with mild, moderate and severe SHT, as outdated designations [57].
6. French-language tradition
French uses commotion cérébrale and contusion cérébrale; the Québec terminology office gives commotio cerebri as the Latin equivalent [58]. It defines contusion as possibly a single focus or more diffuse lesions [59]. French emergency medicine uses traumatisme crânien léger (TCL), defined with the WHO criteria and GCS 13–15 in the 2012 SFMU recommendations [60]. A Québec public-health bulletin reports that commotion cérébrale has long been used in sport, whereas traumatisme cranio-cérébral léger (TCCL) is preferred in medical settings, with concussion included within TCCL [61]. No verified source directly comparing French and German conceptions of contusion was found, so this comparison remains open.
7. Russian-language tradition and Luria
Clinical classification. Russian clinical practice uses cherepno-mozgovaya travma (ChMT, craniocerebral trauma) with lesion type and severity combined in one scheme. In the routine classification described by Zakharov and colleagues, concussion and mild cerebral contusion count as mild; moderate contusion as moderate; and severe contusion, diffuse axonal injury and brain compression as severe [62]. A 1994 paper from Tatarstan states that concussion and mild contusion are closely related in symptoms but differ in duration of disability, and therefore in forensic grading of bodily harm [63]. It cites the Soviet clinical classification of 1986, which was not retrieved. The Burdenko Institute classification has been described in Lichterman's papers [64–66]. As in the German tradition, part of the pressure for sharp lesion-based categories comes from assessment of consequences.
Luria. Luria's post-war work belongs to a different branch of the field. During the Second World War he worked at evacuation hospital No. 3120 in Kisegach in the Urals. Its profile was wounds with brain damage, mainly gunshot wounds of the head and consequences of explosive and artillery trauma, and he remained there until the end of 1944 [67]. His books Traumatic Aphasia (1947) [68] and Restoration of Function after Brain Injury (1948) [69] grew from this material, and he describes the wartime programme in his autobiography [70]. His Kisegach work diary has been published [71]. British wartime cohorts produced a parallel literature, for example Russell and Espir on aphasia in war wounds of the brain [72].
Assessment, based on the sources retrieved:
The Soviet wartime tradition used mainly open, penetrating wounds with focal lesions to build localisation-based syndrome analysis and a theory of recovery.
The British tradition used military cohorts to build time-based measures, above all PTA.
Neither addressed the concussion-terminology question directly in any source that could be verified.
Luria's relevance to this article is therefore conceptual (syndrome analysis, recovery of function) and not terminological.
8. Sport-related concussion
The Concussion in Sport Group held its first conference in Vienna in 2001 [73]. Its definitions were reviewed systematically before the 2016 Berlin meeting [74]. The Amsterdam 2022 statement defines sport-related concussion as a traumatic brain injury caused by a direct blow to the head, neck or body in sport and exercise-related activities, with an impulsive force transmitted to the brain that initiates a neurotransmitter and metabolic cascade, with possible axonal injury, blood flow change and inflammation [75]. The concurrent ACRM update of the mTBI definition meant that a single conceptual and operational definition was not reached [47, 75].
The neurometabolic cascade framework [76, 77] helps explain why a normal GCS does not exclude pathophysiological change [76]. Consensus thresholds for persisting symptoms changed between statements. The Berlin 2016 statement specified persistent symptoms as those lasting longer than 10–14 days in adults (as quoted by Quinn and colleagues) [78]. The Amsterdam 2022 statement defines persisting symptoms as lasting more than four weeks in children, adolescents and adults [75]. DSM-5 omitted postconcussional disorder in favour of mild or major neurocognitive disorder due to TBI. ICD-10 retains "postconcussional syndrome" without a duration criterion. Most guidelines now refer to "symptoms" rather than "syndrome" because of the non-specificity of the complaints [78]. The German guideline lists ICD-10 F07.2 (organic psychosyndrome after SHT) and ICD-11 6E67 for post-traumatic cognitive disorders [33]. A 2017 review recommends a probabilistic rather than definitive diagnostic and prognostic framework for mTBI [79].
Terminology may itself influence outcome. In a non-clinical sample, giving an identical injury description different labels (concussion, minor head injury, mild TBI) changed expected symptoms and illness perceptions [80], and early beliefs about serious lasting consequences predicted enduring symptoms at three months beyond injury severity, post-traumatic stress, anxiety and depression [81].
9. Summary table (usage varies within each language)
| Concept | English | German | French | Russian |
|---|---|---|---|---|
| Transient functional disturbance after mechanical force | concussion | Commotio cerebri, Gehirnerschütterung (ICD-10-GM S06.0) | commotion cérébrale | сотрясение головного мозга† |
| Structural bruising | contusion | Contusio cerebri, Hirnprellung (S06.3- circumscribed; S06.2- diffuse) | contusion cérébrale | ушиб головного мозга†, graded mild/moderate/severe |
| Pressure damage | compression | Compressio cerebri (historical; not an own code in the guideline excerpt) | not verified | сдавление головного мозга† (counted as severe) |
| Mild grade | mild TBI (GCS 13–15; WHO/ACRM criteria) | leichtes SHT (GCS 13–15); often used as synonym for commotio, which the 2024 guideline rejects | TCL / TCCL | concussion and mild contusion both counted as mild |
| Post-concussion state | post-concussion syndrome; persisting symptoms | postkommotionelles Syndrom‡ | syndrome subjectif post-traumatique | not verified |
†Cyrillic forms from standard usage and not checked against a cited source. ‡Taken from a lay-oriented source. French and Russian cells and the French–German comparison of contusion are not verified; "not verified" marks cells for which no source was found.
10. What the history shows
Commotio and contusio began as lesion terms and became clinical terms.
Severity scales (GCS, PTA, duration of unconsciousness) were added from the 1940s to 1970s, and "mild" then absorbed both reversible and structural injury.
German and Russian traditions keep lesion categories partly because assessment of consequences requires them. English-language usage shifted toward severity grades and operational mTBI criteria.
Sport medicine introduced concussion as the main clinical label and mTBI as a near-synonym, but consensus bodies have not yet agreed on a single definition.
The same word can therefore refer to a functional syndrome, a lesion, a severity grade or a diagnostic category depending on language, specialty and purpose.
Evidence notes
This is a narrative history written for a general readership. The following limits apply to how the sources were checked.
Bibliographic details were confirmed against indexed records or publisher pages for most 20th- and 21st-century journal articles. The AWMF guidelines (2015 and 2024) and several abstracts were read directly. The 2015 guideline is marked as not updated for more than five years; a newer adult guideline may exist.
Early sources (Lanfranc, Berengario, Paré, Petit) and several 1920s–1930s and 1970s references are taken from reference lists in secondary works. The primary texts were not seen.
The attribution of the commotio/contusio/compressio scheme to Petit rests on a German teaching script. The German-versus-English difference in the meaning of concussion rests on one Japanese review of the 1979 Glossary that could not be re-checked.
Details of the Russian classification (including the 1986 Soviet scheme), the Cyrillic and French table cells, and the French–German comparison of contusion are not verified. The Luria section relies on a university web article and his autobiography, and makes only a conceptual point.
Two German lay sources were used only to show that Gehirnquetschung is applied to both contusio and compressio.
The Amsterdam 2022 definition was read through a 2024 reprint. Some citation details (journal names, volumes and page ranges for refs 3, 7, 12, 23, 47, 69 and 72) are incomplete.
Statements marked “assessment” are interpretations by the authors of this article and not findings of the cited sources.