Tag: mbbs practical

The CNS examination is where practical exams are quietly won or lost. Cardiac and respiratory exams forgive a little fumbling. The neuro exam does not — one skipped step and the examiner knows you’re reciting instead of examining.

This is the exact sequence I use on ward rounds and in front of internal examiners, in the order that keeps you from missing anything. Practise it on a partner until it becomes muscle memory.

Before you touch the patient

• Wash hands, introduce yourself, take consent.
• Position: patient lying comfortably; you examine from the right side.
• Expose only what you’re examining; keep the patient covered otherwise.
• Equipment: tendon hammer, tuning fork (128 Hz), torch or ophthalmoscope, cotton wisp, pin, test tubes of warm/cold water, tongue depressor, Snellen chart, two objects (e.g., coin and key) for cortical sensation.

The sequence (memorise this order)

Higher function → Cranial nerves → Motor → Reflexes → Sensory → Coordination → Gait → Meningeal signs.

1. Higher mental functions

Assess level of consciousness, orientation to time/place/person, attention and memory, and speech. For a formal assessment use the MMSE or MoCA. Note behaviour and whether the patient is cooperative — this shapes how much of the exam you can trust.

2. Cranial nerves I–XII

Nerve	How you test it
I — Olfactory	Non-irritant smells (often only tested if history suggests)
II — Optic	Visual acuity, fields, colour vision, fundus, pupillary light reflex
III, IV, VI	Pupil (III), eye movements in all directions, diplopia; check ptosis
V — Trigeminal	Facial sensation (3 divisions), corneal reflex, masseter/temporalis power, jaw jerk
VII — Facial	Forehead wrinkling, eye closure, smile, puff cheeks (UMNL vs LMNL)
VIII — Vestibulocochlear	Rinne and Weber (hearing), nystagmus/vertigo, Romberg
IX, X	Gag reflex, palatal movement, uvula position, voice quality, swallow
XI — Accessory	Shoulder shrug (trapezius), head turn against resistance (sternocleidomastoid)
XII — Hypoglossal	Tongue protrusion, look for deviation and fasciculations

Say the pattern out loud: “Cranial nerves — no deficit detected,” or describe the exact abnormality. The examiner listens for whether you can localise the lesion.

3. Motor system

• Inspection: bulk, wasting, fasciculations, abnormal posturing.
• Tone: passively flex/extend each limb — note spasticity (clasp-knife, UMNL) vs rigidity (lead-pipe/cogwheel, extrapyramidal) vs flaccidity (LMNL).
• Power: grade 0–5 (MRC). Test proximally and distally in each limb.
• Nutrition: muscle tenderness, involuntary movements, coordination of movement.

Grade	Meaning
0	No contraction
1	Flicker only
2	Movement with gravity eliminated
3	Movement against gravity
4	Against gravity + some resistance
5	Normal power

4. Reflexes

• Deep tendon reflexes: biceps (C5–6), triceps (C7–8), supinator (C5–6), knee (L3–4), ankle (S1–2). Grade 0 = absent, 4+ = clonus.
• Superficial reflexes: abdominal, cremasteric, plantar (Babinski).
• Primitive/abnormal: Hoffman, clonus — if present, document carefully.
• Always compare both sides and interpret in context (UMNL: brisk + Babinski; LMNL: reduced).

5. Sensory system

• Superficial: fine touch, pain (pinprick), temperature — dermatome by dermatome.
• Deep/kinaesthetic: vibration (128 Hz tuning fork), joint position sense.
• Cortical: two-point discrimination, stereognosis, graphesthesia, extinction.
• Map any deficit to a pattern: dermatomal, peripheral nerve, or a spinal level.

6. Coordination

• Finger–nose and heel–shin tests (intention tremor, dysmetria).
• Dysdiadochokinesia: rapid alternating movements.
• Romberg’s test: standing, feet together, eyes open then closed.

7. Gait and station

Observe a normal walk, then ask for tandem gait, heel and toe walking. Note hemiplegic, ataxic, parkinsonian, waddling or steppage gait — each points to a different lesion.

8. Meningeal signs

Neck stiffness, Kernig’s sign, Brudzinski’s sign — critical when infection is suspected.

How to present your findings

“On examination of the central nervous system: higher mental functions were normal; no cranial nerve deficit; tone and power were normal in all four limbs with grade 5 power; deep tendon reflexes were normal and symmetric; plantar reflexes were flexor bilaterally; sensory and coordination testing were normal; gait was normal; no meningeal signs.”

Then, if abnormal: state the net pattern and the site of the lesion. That single line — pattern plus localisation — is what separates a pass from a distinction.

Viva traps that actually come up

• Difference between UMNL and LMNL signs (tone, reflexes, plantar, wasting, fasciculations).
• Which cranial nerve and which side in a given stroke syndrome.
• How you localise a hemiplegia vs a mononeuropathy vs a radiculopathy.
• Why you test vibration with a 128 Hz fork specifically, and joint position sense both sides.
• What Romberg’s sign positive actually indicates (proprioceptive deficit, not cerebellar).

Before your next posting, skim my first-year MBBS book list to be sure the examination guides you own are the right ones, and explore more clinical-skills and viva guides.

Educational use only. This guide is written for medical students and is not medical advice. Clinical protocols, drug doses and guidelines change — always verify against the latest standard textbooks and official NMC / institutional guidance before applying anything in practice. Read the full disclaimer.

Frequently Asked Questions (FAQ)

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