Vincenzo Neri (1880-1960) and his sign to detect leg weakness due to corticospinal tract injury.

The Italian neurologist Vincenzo Neri (1880-1960), a pupil of Joseph Babinski (1857-1932), greatly contributed to refining the semiotics of neurological examination and was a pioneer in medical cinematography. In 1909, Neri proposed a sign to diagnose leg paresis due to a pyramidal tract lesion. According to Neri, if a patient standing with the legs apart and the arms crossed on the chest bends the trunk of the pelvis, when the trunk has almost reached the horizontal line, the leg on the paralyzed side flexes, whereas the unaffected leg remains extended. This sign reflects a spinal hyperfunctioning emerging after a pyramidal lesion, and should be interpreted as a part of a triple flexion reflex. Beyond the acute stage, it could reflect an unusual pattern of flexor spasticity involving the lower limb due to corticospinal tract injury. The sign described by Neri retains its validity in identifying this organic leg weakness due to pyramidal lesions, particularly when it is mild or in its early stages.

Adolph Seeligmüller (1837-1912) and the first graphic illustration of the "toe phenomenon" (later called "Babinski sign") in the medical literature.

The "toe phenomenon" refers to the extension (dorsiflexion) of the great toe, which occurs instead of the normal flexion following stimulation of the foot sole. Its clinical significance was not fully appreciated until Joseph Jules François Félix Babinski (1857-1932) described it in 1896. In 1881, Ernst Strümpell (1853-1925) had described a continuous (tonic) extension of the big toe, a finding that years later the French neurologist Jean-Athanase Sicard (1872-1929) recognized as an equivalent of the "toe phenomenon", also indicating pyramidal tract dysfunction. Previously, this phenomenon had been mentioned in patients only passingly and without providing a picture of it. In 1887, the German neurologist Adolph Seeligmüller (1837-1912) mentioned the tonic extension of the big toe among the characteristic clinical features of spastic infantile hemiplegia-a condition first described by the Austrian physician Moritz Benedikt (1835-1920) in 1868. Seeligmüller incorrectly attributed the tonic extension of the big toe to spastic contracture of the extensor hallucis longus muscle. However, he put great emphasis on this sign and considered it worth being illustrated. Adolph Seeligmüller therefore provided the very first graphic illustration of the (tonic) "toe phenomenon" in the medical literature. Of note, the first photographic illustration of this sign made by Babinski appeared only in 1900, when it had already been adopted by neurologists all over the world.

Camillo Negro (1861-1927) and his method for eliciting the extensor toe sign.

The "toe phenomenon", or extensor toe sign, is characterized by the extension (dorsiflexion) of the great toe elicited by plantar stimulation, and indicates pyramidal tract dysfunction. This phenomenon was first extensively described and studied by Joseph Jules François Félix Babinski (1857-1932), who introduced it in clinical practice. In 1912, the famous Italian neurologist Camillo Negro (1861-1927) proposed a new method of eliciting the extensor toe sign by inviting the patient, lying in bed in dorsal decubitus position, to raise the paretic limb with the leg extended on the thigh. This sign appeared during voluntary effort and could not be elicited by raising the unaffected lower limb. Negro was also the first to investigate the influence of cold upon the appearance of the "toe phenomenon" and to propose the use of (faradic) electrical stimulation to evoke it.

Rotator drift: A sign of upper motor neuron leg weakness.

OBJECTIVE: There are techniques for eliciting subtle arm weakness (pronator drift), but the accompanying abnormal reflex response (Hoffmann's sign) is of limited value; conversely, in the leg there are no techniques for eliciting subtle weakness equivalent to pronator drift, but there is a robust abnormal reflex response (Babinski's sign). Thus, there is a need to devise a simple and rapid technique for detecting leg weakness capable of being used in either cooperative or comatose patients. PATIENTS AND METHODS: Using three patient groups (discovery set, training set, test set) a technique for detecting upper motor neuron (UMN) lesion leg weakness was devised. RESULTS: With the patient supine, the examiner grasps both big toes, pointing them towards the ceiling with the long axis of the foot perpendicular to the bed; the patient is asked to maintain this position for 30 s. People with pyramidal tract weakness show external rotator drift on their weak side: on the normal side the foot is deviated 20-25° from the perpendicular, on the paretic side the foot is deviated more than 30°. CONCLUSION: This rotator drift sign is a simple method for detecting subtle UMN leg weakness. When combined with the pronator drift sign, these two signs constitute "pyramidal drift" signs for the bedside detection of UMN hemiparetic weakness.

A New Method of Eliciting Pyramidal Tract Impairment in Adults.

BACKGROUND: To suggest a new way of eliciting pyramidal tract dysfunction in adults since the most widely utilized plantar reflex, which is the Babinski reflex, has limitations with different reliability and consistency among different examiners. MATERIALS AND METHODS: 168 adult subjects were examined for the new sign in addition. It consists of just an observation of the patient's feet and toes in a conscious patient looking for the extension of the great toe along with fanning, spreading and plantar flexion of the small toes either at rest or when patient elevates one leg up at a time. RESULTS: We were able to observe the extension of the great toe along with fanning, spreading and plantar flexion of the small toes in patients with impairment of pyramidal tract. The specificity was 94% while the sensitivity was 96%. CONCLUSION: Pyramidal tract lesion in adults can be elicited by this new test that observes the extension of the great toe along with fanning, spreading and plantar flexion of the small toes in patients. We suggest this sign as a complement to established signs like Babinski reflex.

Does the Babinski sign predict functional outcome in acute ischemic stroke?

OBJECTIVE: The aim of this prospective cohort study was to determine the incidence and neuroimaging risk factors associated with Babinski sign following acute ischemic stroke, as well as its relationship with the functional outcome of patients. METHODS: A total of 351 patients were enrolled in the study within 7 days of acute ischemic stroke. The Babinski sign along with other upper motor neuron signs were examined upon admission and between days 1 and 3 and days 5 and 7 after admission. Neuroimaging parameters included site and volume of infarction and white matter lesions. All patients were followed up at 3 months. Functional outcome was assessed with the Lawton Activities of Daily Living scale and modified Rankin Scale. RESULTS: Babinski sign was observed in 115 of 351 (32.8%) patients in the acute ischemic stroke. These patients had higher National Institutes of Health Stroke Scale (NIHSS) scores at admission and higher rates of atrial fibrillation and cardioembolism; higher frequencies of frontal, temporal, and limbic lobes and basal ganglia infarcts; and larger infarct volume. Higher NIHSS score and basal ganglia infarct were significant predictors of the presence of Babinski sign. After adjusting for confounds, the presence of Babinski sign did not predict poor functional outcome. CONCLUSION: The incidence of Babinski sign was 32.8% in the acute ischemic stroke. Severe infarction and basal ganglia infarct were independent predictors of Babinski sign. Although Babinski sign is common in acute ischemic stroke patients, it does not predict poor functional outcome 3 months later.

A systematic and quantitative evaluation of plantar stimulation: The effect of type, pattern, force of stimulation in eliciting an accurate plantar response.

OBJECTIVES: Systematic and quantitative evaluation of the plantar reflex has been infrequently studied in the past and can help assess the vexing variables encountered in its elicitation. The objective of this study was to determine the effect of type, pattern and force of stimulation in eliciting an accurate plantar response in patients with pyramidal dysfunction and healthy individuals. PATIENTS AND METHODS: A special instrument was designed to give a predesigned force of stimulus. The plantar surface of foot was divided into nine parts and point and stroke stimulations were studied systematically in pyramidal weakness feet (cases) and healthy control feet (controls) with predefined forces. Results were tabulated and statistically analysed. RESULTS: Stroke stimulation was superior to point stimulation in eliciting plantar response. There was no significant difference in the responses to the three predefined forces used for stroke stimulations. Sensitivity of Babinski sign was 72.9% and specificity was 100%. In pyramidal weakness feet, extensor responses were significantly elicited from lateral starting stroke patterns (67%) and on moving medially they were replaced by flexor responses (44%). Withdrawal responses increased with the stimulations reaching the distal foot and with the curvilinear component of stimulations. Sensitivity responses (related to the sensitivity of an individual) contaminate the plantar response and occasionally make its interpretation difficult. In subjects with bilateral sensitivity with unilateral disease, knowing the sensitivity pattern on the normal side improved the interpretation of plantar response on the abnormal side. CONCLUSIONS: Based on this study, the optimal method for eliciting Babinski sign accurately is to stroke the lateral aspect of the sole of the foot in a straight line up to mid foot. This should be performed in both feet three times, and if the weakness is unilateral, it should be performed in the normal leg first to aid interpretation of the affected leg.

Relevance of the pyramidal syndrome in amyotrophic lateral sclerosis. / Relevancia del síndrome piramidal en la esclerosis lateral amiotrófica.

INTRODUCTION: Pyramidal signs (hyperreflexia, spasticity, Babinski sign) are essential for the diagnosis of amyotrophic lateral sclerosis (ALS). However, these signs are not always present at onset and may vary over time, besides which their role in disease evolution is controversial. Our goal was to describe which pyramidal signs were present and how they evolved in a cohort of patients with ALS, as well as their role in prognosis. METHODS: Retrospective analysis of prospectively collected patients diagnosed with ALS in our centre from 1990 to 2015. RESULTS: Of a total of 130 patients with ALS, 34 (26.1%) patients showed no pyramidal signs at the first visit while 15 (11.5%) had a complete pyramidal syndrome. Of those patients without initial pyramidal signs, mean time of appearance of the first signs was 4.5 months. Babinski sign was positive in 64 (49.2%) patients, hyperreflexia in 90 (69.2%) and 22 (16.9%) patients had spasticity. Pyramidal signs tended to remain unchanged over time, although they seem to appear at later stages or even disappear with time in some patients. We found no association between survival and the presence of changes to pyramidal signs, although decreased spasticity was associated with greater clinical deterioration (ALSFR scale) (P<.001). CONCLUSION: A quarter of patients with ALS initially showed no pyramidal signs and in some cases they even disappear over time. These data support the need for tools that assess the pyramidal tract.

The Babinski Sign: A comprehensive review.

The Babinski Sign is one of the most clinically relevant diagnostic signs in medicine. Though the plantar reflex is practiced thousands of times across the globe every day, few realize its historical importance. In this narrative review we trace the origins of the Plantar Reflex back in the 19th century, discuss its evolution over time and examine the body of evidence behind the current understanding. State of the art diagnostic modalities like video analysis and electromyography have helped us in dissecting the pathophysiology behind the simple yet beautiful Babinski Sign.

The Interrater Reliability of Subjective Assessments of the Babinski Reflex.

The Babinski reflex is a clinical diagnostic tool; however, the interrater reliability of this tool is currently greatly contested. A comparison between rater groups with objective measurements of the Babinski reflex was therefore conducted. Fifteen recorded Babinski reflexes were assessed by 12 neurologists and 12 medical students as being either pathological or nonpathological. Kinematic and electromyographic variables were collected and used to assess which aspects of the Babinski reflex predict classification. Substantial interrater agreement within the neurologist and student groups (κ = .72 and .67, respectively) was shown; however, there were some differing aspects between what neurologists and students used to assess the reflex as determined by objective kinematic measurements.

Clinical, Radiologic, and Legal Significance of "Extensor Response" in Posttraumatic Coma.

OBJECTIVE: The timely detection of neurologic deterioration can be critical for the survival of a neurosurgical patient following head injury. Because little reliable evidence is available on the prognostic value of the clinical sign "extensor response" in comatose posttraumatic patients, we investigated the correlation of this clinical sign with outcome and with early radiologic findings from magnetic resonance imaging (MRI). METHODS: This retrospective analysis of prospectively obtained data included 157 patients who had remained in a coma for a minimum of 24 hours after traumatic brain injury. All patients received a 1.5-T MRI within 10 days (median: 2 days) of the injury. The correlations between clinical findings 12 and 24 hours after the injury-in particular, extensor response and pupillary function, MRI findings, and outcome after 1 year-were investigated. Statistical analysis included contingency tables, Fisher exact test, odds ratios (ORs) with confidence intervals (CIs), and weighted κ values. RESULTS: There were 48 patients with extensor response within the first 24 hours after the injury. Patients with extensor response (World Federation of Neurosurgical Societies coma grade III) statistically were significantly more likely to harbor MRI lesions in the brainstem when compared with patients in a coma who had no further deficiencies (coma grade I; p = 0.0004 by Fisher exact test, OR 10.8 with 95% CI, 2.7-42.5) and patients with unilateral loss of pupil function (coma grade II; p = 0.0187, OR 2.8 with 95% CI, 1.2-6.5). The correlation of brainstem lesions as found by MRI and outcome according to the Glasgow Outcome Scale after 1 year was also highly significant (p ≤ 0.016). CONCLUSION: The correlation of extensor response and loss of pupil function with an unfavorable outcome and with brainstem lesions revealed by MRI is highly significant. Their sudden onset may be associated with the sudden onset of brainstem dysfunction and should therefore be regarded as one of the most fundamental warning signs in the clinical monitoring of comatose patients.

Kinematic and kinetic analysis of the inter- and intra-applicator assessment of the Babinski reflex.

AIMS OF THE STUDY: The first aim was to quantify variability in the mechanical technique used by neurologists to elicit the Babinski reflex. The second aim of the study was to assess if the mechanical technique is an important determinant of the subsequent reflex response. MATERIALS AND METHODS: In this study, twelve neurologists elicited the Babinski reflex five times on the same foot of the same participant using a special reflex hammer which recorded the force and duration of the stroke. Hallux movement, tibialis anterior maximum EMG amplitude and pain felt by the participant for each stroke were recorded. RESULTS: A large inter- and intra-applicator variability was shown amongst the neurologists. The change in hallux angle was significantly correlated with the duration of the stroke (R(2)=0.18, P<0.01), maximum (R(2)=0.14, P=0.01) and average (R(2)=0.17, P<0.01) force used to elicit the reflex. No correlations were shown between the hammer forces and duration and the maximum amplitude of the tibialis anterior. Significant correlations were shown between the pain score and the maximum (R(2)=0.15, P<0.01) and average (R(2)=0.17, P=0.001) force used to elicit the Babinski reflex. CONCLUSION: These results indicate that there was substantial variation when performing the Babinski reflex test within and between neurologists which could lead to differences in the resultant reflex and therefore may affect subsequent diagnoses.

[Joseph Babinski's contribution to neurological symptomatology].

Joseph Babinski (1857-1932) was an excellent clinician. André Breton, a French poet, described Babinski's way of clinical examination in his Manifeste du surréalisme (1924), which vividly revealed Babinski's meticulous character. Babinski is well known by his eponymous Babinski reflex. Although some predecessors had described this phenomenon briefly, its meaning was interpreted by Babinski. His contribution to neurological symptomatology was not restricted to his plantar skin reflex, but also to other wide area. In this article, symptoms described by Babinski, i.e. plantar skin reflex, cerebellar symptoms including cerebellar asynergy, adiadochokinesis, dysmetria, cerebellar catalepsy, and rising sign, platysma sign, anosognosia are explained and are critically discussed.

Accuracy of the Babinski sign in the identification of pyramidal tract dysfunction.

BACKGROUND: The extensor plantar response described by Joseph Babinski (1896) indicates pyramidal tract dysfunction (PTD) but has significant inter-observer variability and inconsistent accuracy. The goal of this study was to determine the accuracy of the Babinski sign in subjects with verified PTD. METHODS: We studied 107 adult hospitalized and outpatient subjects evaluated by neurology. The reference standard was the blinded and independent diagnosis of an expert neurologist based on anamnesis, physical examination, imaging and complementary tests. Two neurologists elicited the Babinski sign in each patient independently, blindly and in a standardized manner to measure inter-observer variability; each examination was filmed to quantify intra-observer variability. RESULTS: Compared with the reference standard, the Babinski sign had low sensitivity (50.8%, 95%CI 41.5-60.1) but high specificity (99%, 95%CI 97.7-100) in identifying PTD with a positive likelihood ratio of 51.8 (95%CI 16.6-161.2) and a calculated inter-observer variability of 0.73 (95%CI 0.598-0.858). The intraevaluator reliability was 0.571 (95%CI 0.270-0.873) and 0.467 (95%, CI 0.019-0.914) respectively, for each examiner. CONCLUSION: The presence of the Babinski sign obtained by a neurologist provides valid and reliable evidence of PTD; due to its low sensitivity, absence of the Babinski sign still requires additional patient evaluation if PTD is suspected.

The history of examination of reflexes.

In the late 1800s, Wilhelm Erb, Joseph Babinski, William Gowers, and others helped develop the neurologic examination as we know it today. Erb was one of the first to emphasize a detailed and systematic neurologic exam and was co-discoverer of the muscle stretch reflex, Gowers began studying the knee jerk shortly after it was described, and Babinski focused on finding reliable signs that could differentiate organic from hysterical paralysis. These physicians and others emphasized the bedside examination of reflexes, which have been an important part of the neurologic examination ever since. This review will focus on the history of the examination of the following muscle stretch and superficial/cutaneous reflexes: knee jerk, jaw jerk, deep abdominal reflexes, superficial abdominal reflexes, plantar reflex/Babinski sign, and palmomental reflex. The history of reflex grading will also be discussed.