# Eponymous Signs in Neurology and Endocrinology

> Eponymous signs in neurology and endocrinology for NEET-PG Medicine cover Babinski, Chvostek and Trousseau signs, Argyll Robertson pupil and thyroid eye signs.

- Canonical URL: https://prepelephant.com/topics/neet-pg/medicine/eponymous-signs-in-neurology-and-endocrinology
- Exam / course: NEET-PG · Subject: Medicine
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-14
- Last updated: 2026-10-08
- Reference basis: Harrison's Principles of Internal Medicine; Bradley's Neurology in Clinical Practice; Williams Textbook of Endocrinology
- How to cite: "Eponymous Signs in Neurology and Endocrinology", PrepElephant, https://prepelephant.com/topics/neet-pg/medicine/eponymous-signs-in-neurology-and-endocrinology

## Direct answer

Neurological and endocrine eponymous signs are named examination findings that localise a lesion or reveal an electrolyte or hormonal state. Babinski and Hoffmann signs indicate an upper motor neuron lesion, Kernig and Brudzinski signs suggest meningeal irritation, and Chvostek and Trousseau signs point to hypocalcaemia.

## What you must remember

- **Babinski sign:** an extensor plantar response indicating an upper motor neuron lesion, and normal in infants up to about two years.
- **Hoffmann sign:** flicking the middle fingernail elicits flexion of the thumb and index finger, suggesting cervical cord disease.
- **Kernig sign:** resistance to passive knee extension with the hip flexed, indicating meningeal irritation.
- **Brudzinski sign:** passive neck flexion produces flexion of the hips and knees, also a meningeal sign.
- **Chvostek sign:** a facial twitch on tapping the facial nerve in front of the ear, suggesting hypocalcaemia, though it is not always present.
- **Trousseau sign:** carpopedal spasm after blood pressure cuff inflation, reflecting hypocalcaemia.
- **Argyll Robertson pupil:** small, irregular pupils that constrict on accommodation but not to light, classically from neurosyphilis.
- **Thyroid eye signs:** von Graefe lid lag and Stellwag reduced blinking point to thyrotoxicosis.

## Eliciting each sign and reading the result

Each sign depends on a specific manoeuvre, and the manoeuvre determines what a positive result means. Most of these signs are best learned as pairs, so that the lesion or metabolic cause is recalled with the test.

| Sign | How it is elicited | Indicates |
|---|---|---|
| Babinski sign | Stroke the lateral sole | Upper motor neuron lesion |
| Hoffmann sign | Flick the middle fingernail | Upper motor neuron lesion, often cervical |
| Kernig sign | Extend the knee with hip flexed | Meningeal irritation |
| Brudzinski sign | Flex the neck passively | Meningeal irritation |
| Chvostek sign | Tap the facial nerve in front of the ear | Hypocalcaemia |
| Trousseau sign | Inflate a cuff above systolic pressure | Hypocalcaemia |
| Argyll Robertson pupil | Test the light and accommodation reflexes | Neurosyphilis, classically |
| von Graefe sign | Watch the upper lid on downward gaze | Thyrotoxicosis, lid lag |

Upper motor neuron signs appear with weakness and spasticity, while meningeal signs appear with fever and neck stiffness and need urgent evaluation. Chvostek sign is insensitive, so a negative result does not exclude hypocalcaemia.

## Traps in neurological and endocrine signs

Many questions turn on confusing a sign with a similar sign that points to a different diagnosis.

- **Trap:** calling Chvostek sign diagnostic of hypocalcaemia — **Correct:** it is neither sensitive nor specific, so serum calcium with albumin or ionised calcium must confirm the diagnosis.
- **Trap:** confusing Trousseau sign with its association with malignancy — **Correct:** the malignancy sign is migratory superficial thrombophlebitis, while carpopedal spasm after cuff inflation is the hypocalcaemia sign.
- **Trap:** describing an Argyll Robertson pupil as a sluggish pupil to light — **Correct:** it constricts on accommodation but does not react to light, a pattern called light-near dissociation.

## Frequently asked questions

### Why does a Babinski sign indicate an upper motor neuron lesion?

A Babinski sign is an extensor plantar response, which appears when descending corticospinal inhibition is lost. The primitive reflex is then released, so the big toe dorsiflexes, and this response is normal in infants up to about two years.

### What is the difference between Kernig sign and Brudzinski sign?

Kernig sign is resistance to knee extension with the hip flexed, while Brudzinski sign is involuntary flexion of the hips and knees on passive neck flexion. Both indicate meningeal irritation, most often from bacterial meningitis, but they are insensitive in infants and in some adults.

### Which eye signs suggest thyrotoxicosis?

Von Graefe sign of lid lag, Stellwag sign of infrequent blinking and Dalrymple sign of lid retraction all point to thyrotoxicosis. These lid signs are common in Graves disease, which also explains exophthalmos as a separate finding.

### What does an Argyll Robertson pupil suggest?

An Argyll Robertson pupil is small, irregular and accommodates normally but does not react to light. It classically suggests neurosyphilis, though it has also been described in diabetes, so syphilis serology is the usual test.