Neurol India Home 

Year : 2017  |  Volume : 65  |  Issue : 6  |  Page : 1445--1447

Patellar jerks in the 3-Tesla era: No knee-jerk excitement anymore!

Bobby Iype, George C Vilanilam 
 Department of Neurosurgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India

Correspondence Address:
Dr. George C Vilanilam
Department of Neurosurgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum - 695 011, Kerala

How to cite this article:
Iype B, Vilanilam GC. Patellar jerks in the 3-Tesla era: No knee-jerk excitement anymore!.Neurol India 2017;65:1445-1447

How to cite this URL:
Iype B, Vilanilam GC. Patellar jerks in the 3-Tesla era: No knee-jerk excitement anymore!. Neurol India [serial online] 2017 [cited 2023 Mar 21 ];65:1445-1447
Available from:

Full Text


“I was taught to tap and thump my patients and listen for the signs of sickness and health”

Dr. Abraham Verghese, Bedside Manners (2007)

Gone are the days when a brisk knee jerk would set the neurology resident's adrenaline racing. The patellar clonus too, fails to excite anymore. Professor Kalyan Bhattacharyya's illuminating articles [1],[2] on the deep tendon jerk, Babinski reflex, and percussion hammer as an iconic trademark signature of a neuroclinician, struck a chord of nostalgia and excitement. In the era of high-resolution structural imaging, bedside clinical tests are often considered tedious, humdrum, and old fashioned.[3] The clinician's gentle diagnostic touch has now sadly been preceded or replaced by a phlebotomist's blood sampling prick or the inanimate nudge of the magnetic resonance imaging (MRI) head support foam.

Hence, we were inspired to evaluate the contemporary relevance of bedside neurological tests in the 3 Tesla MRI era. It was postulated that bedside clinical tests could have varying diagnostic significance as follows:

Stand-alone relevance (of diagnostic value on their own, even without imaging)Complementary relevance (additional imaging/tests needed for the clinical tests to be of value)Archaic relevance (of academic or theoretical value only).

It is estimated that 90% of the illnesses can be diagnosed by history, clinical examination, and basic bedside tests, although examination alone may have a diagnostic yield of only 1%. A startling revelation by Nicholl et al., in a study from UK, revealed that 33% of the patients referred to neurology departments by physicians, do not recollect being examined by a percussion hammer and 48% were never examined by an ophthalmoscope. However, only 4% could recall not being examined by a stethoscope.[4]

The i-patient

In today's digital era, ward rounds can entirely be conducted telemetrically, by a doctor from afar, using telemedicine facilities. All relevant vital parameters, tests, and their trends can be easily monitored electronically without physical bedside presence. Electronic medical records (EMR) have replaced handwritten clinical notes and artistic operative diagrams.[3] Drop down menus of symptoms and medications have brought in the era of the i-patient just like the i-phone, i-pad, i-pod, etc., Clinical case presentations are now entirely held around computer consoles, and bedside visits are often a rarity. Not to be left behind in the digital era, clinicians have also caught up, in software and sophistication, with their peers in other fields.[3],[4]

The real patient

Diagnostic tests and imaging as first-line diagnostic endeavours, have gradually replaced physical examination.[3] Nevertheless, a doctor's touch, though old fashioned, is still an immensely powerful tool. It is a sacred ritual of diagnostic value to the physician and of reassuring value to the patient. Its significance in caring for a real, “flesh and blood” patient cannot be emphasized further. The “Stanford 25,” popularized by Abraham Verghese,[3] are a set of essential clinical bedside tests, which outline the bare minimum tests that may have contemporary relevance. Critics of such a ritualistic approach feel that it may be too cumbersome in a busy outpatient or emergency service. Hence, tailor-made clinical examination to suit the symptom profile seems more appropriate.[3],[4]

Sceptics of bedside clinical tests feel that they lack objectivity. Hence, the recent concept of evidence-based physical examination (EBPE) has emerged, wherein the accuracy of these examinations is tested using sensitivity, specificity, likelihood ratios, and predictive values. However objective we try to make it, symptoms and signs have a certain element of uniqueness in every individual patient and their relevance cannot always be objectified.[4]


“The map is not the territory”

Alfred Korzybski (Polish-American scientist and philosopher), Science and Sanity (1933).

These words imply that, although a technically correct map provides a good picture of the territory, it could still fall short in some aspects. The same can be said about the stand-alone value of imaging in medical sciences. Although the structure of a diseased organ can be mapped, a lot about its “diseased function” still needs the doctor's touch to be deciphered and corrected.[3],[4]

Detaching clinical examination from sophisticated tests and imaging could cause immense clinical embarrassment, treatment errors, and medicolegal weak spots. In this context, we recollect a true incident, the case of a young lady posted for stereotactic brain biopsy for a thalamic mass, at a reputed academic centre a few years ago. The differential diagnosis was brain metastasis and the entire battery of metastatic workup was run, which was surprisingly negative. This included endoscopies, larygoscopy, abdominal computed tomography (CT), serum tumors markers, etc. One could imagine the treating team's embarrassment when the anesthetist, while placing an electrocardiogram electrode and inducing anesthesia for the stereotactic biopsy, discovered a fungating breast ulcer.

Traditional medicine relied heavily on symptom patterns and history taking for making a diagnosis.[5],[6] “Inspection” or “close observation of the diseased” as a clinical tool was the first to emerge into clinical medicine practice. Percussion, described by Auenbrugger in 1761, was earlier used to test the fullness of wine caskets in cellars. Auscultation came in 1817 when Rene Laennec devised the stethoscope. Helmholtz's ophthalmoscope in 1850, and the percussion hammer in 1875 used by Wilhelm Heinrich Erb and Carl Friedrich Otto Westphal were the first instruments used for the bedside clinical examination.[3],[4],[5]

While inspection, palpation, and percussion are fast becoming lost arts, whether or not we should give them up altogether is a matter of debate.[3] Digital stethoscopes can pick up the faint murmur far more reliably than the most astute cardiologist's ear. However, the stethoscope placed on the chest conveys far more than the information its acquires. It denotes a touch of care and comforts the sick. The same is true of the percussion hammer, wisp of cotton, tongue depressor, etc., The clinician's touch also plays a role in choosing the most effective investigation from a plethora of many. Numerous diagnoses are still made just on the basis of an intuitive bedside examination, gut feeling, or sixth sense. Investigations often just crystallize this intuition and give it an objectivity.[4],[5],[6] The screening value of bedside tests to choose the best investigation has always appealed, especially in resource-crunched nations.

Essential and core neurological bedside exam

Moore and Chalk refer to 22 essential items for conduction of a core neurological examination, including fundoscopy, light reflex, visual field, pursuit extraocular movement, facial muscle, tongue, tandem gait, pronator drift, rapid alternating movements of arms, finger-nose test, tone in arms and legs, power in arms and legs, reflexes (biceps, brachioradialis, triceps, patellar, Achilles, plantar), and light touch.[5] It may be too tedious in a busy outpatient or emergency setup to ritualistically perform the entire battery of bedside tests.[4],[5] Hence, several authors advocate a tailor-made examination to throw further light on the symptoms.[7],[8]

When clinical examiners are blinded to history and imaging, the stand-alone diagnostic yield of bedside neurological tests can be interesting. Anderson et al., studied the value of clinical tests alone performed by examiners blinded to history and imaging in 46 patients with focal cerebral lesions and 19 controls.[8] It was found that the upper limb tests with the highest sensitivities for focal lesion detection were finger rolling (0.33), power (0.30), rapid alternating movements (0.30), forearm rolling (0.24), and pronator drift (0.22), with all these tests having a specificity of 1.0. These tests detected a focal lesion in 50% of the patients with such problems. Overall, neurological examination detected a focal lesion in 61% of the patients with imaging-proven focal disease.[8]

Cleared by “the normal scan”

Scans and tests are often performed to “clear” the patient and to “just be sure” that nothing is amiss. This conveys a sense of unreliability in the history, clinical examination, and unsureness on the doctor's part. Unnecessary imaging occasionally creates two potentially alarming clinical scenarios – VOMIT (victims of medical imaging technology);[9] and, a false reassurance in the presence of ominous ailments with a deceptively normal scan [Table 1]. VOMIT includes the entire gamut of benign and nonspecific radiological findings in “normal” people that may lead to undue anxiety, unnecessary referrals, and sometimes surgical intervention too. Nevertheless, in the era of insurance driven medical care and medicolegal watchdogs, “clearing” a patient without an imaging test is difficult to fathom. It may be justified only in a busy and resource-crunched setup where overenthusiastic imaging maybe an overkill, compromising care to the truly deserving and adding to the cost.{Table 1}

Evolutionary inevitability

As objectivity and automation creeps into clinical neurology, the beauty and subjectivity of symptoms/signs are on the verge of extinction.[6] Perhaps, this evolution is inevitable as we try to fit everything into drop-down menus and concrete diagnostic labels. Verghese, Ofri, and several other renowned clinicians vehemently pitch for clinical bedside examination, not just for diagnosis but more so for trust, empathy and relationship building.[3],[4],[5],[6],[7] The emotional rapport and connect it establishes extends far beyond the skin–to-skin contact.

However automated our neurological practice may evolve into, it cannot outgrow bedside tests even in the current era of software and sophistication.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


1Bhattacharyya KB. Deep tendon reflex: The background story of a simple technique. Neurol India 2017;65:245-9.
2Bhattacharyya KB. 1892 and the tribulations of Joseph Babinski. Neurol India 2017;65:468-70.
3Verghese A, Horwitz RI. In praise of the physical examination. BMJ 2009;339:b5448.
4Nicholl DJ, Appleton JP. Clinical neurology: Why this still matters in the 21st century. J Neurol Neurosurg Psychiatry 2015;86:229-33.
5Moore FG, Chalk C. The essential neurologic examination What should medical students be taught? Neurology 2009;72:2020-3.
6Vilanilam GC, Mahadevan A, John PK, Das JM. Clinicopathological conferences: The fading art of playing Sherlock Holmes. Neurol India 2017;65:685-8.
7Elrington G. Three minute neurological examination. Available from: [Last accessed on 2017 May 15].
8Anderson NE, Mason DF, Fink JN, Bergin PS, Charleston AJ, Gamble GD. Detection of focal cerebral hemisphere lesions using the neurological examination. J Neurol Neurosurg Psychiatry 2005;76:545-9.
9Hayward R. Personal View: VOMIT (victims of modern imaging technology)-an acronym for our times. BMJ 2003;326:1273.