SN4
SHORT NOTE
5M
★ High-yield
Write a short note on Primitive (Neonatal) Reflexes.
Definition
- Primitive reflexes are stereotyped, involuntary motor responses present at (or soon after) birth, mediated by the brainstem and spinal cord.
- They appear and disappear at predictable ages; their persistence or absence is a sensitive marker of neurological abnormality.
Important Primitive Reflexes
| Reflex | How elicited | Appears | Disappears |
|---|---|---|---|
| Moro | Sudden head drop → arm abduction-extension then adduction-flexion with cry | Birth | 3–6 months |
| Rooting | Stroke cheek → head turns, mouth opens | Birth | 3–4 months |
| Sucking | Object in mouth → sucking | In utero | 2–4 months |
| Palmar grasp | Object in palm → grip | Birth | 5–6 months |
| Plantar grasp | Pressure on sole → toes curl | Birth | 9–12 months |
| ATNR ('fencing') | Head turned → same-side limbs extend, opposite flex | Birth–1 mo | 5–6 months |
| Stepping | Held upright, sole touches surface → stepping | Birth | 2–3 months |
| Galant | Stroke paravertebral skin → trunk curves to that side | Birth | 2–4 months |
Postural (protective) Reflexes — Appear Later
- Landau reflex — appears ~3 months.
- Lateral propping — appears ~6 months.
- Parachute reflex — appears ~6–9 months; its absence beyond 9–10 months is abnormal (a prerequisite for protective sitting/standing).
Clinical Significance
- Absent at birth → CNS depression, prematurity, or severe illness.
- Persistence beyond the expected age → an upper motor neuron lesion, e.g. Cerebral palsy.
- Asymmetry (e.g. Unilateral Moro) → Erb's palsy, fractured clavicle, or hemiplegia.
- A useful bedside screen for the integrity of the developing nervous system.
All questions in Growth & Development
- Q1Describe the anthropometry & Growth Charts of Normal Physical Growth & Its Assessment. ★
- Q2Discuss Normal Development & Developmental Milestones — its causes, clinical features and management. ★
- Q3Define Short Stature — Approach, Causes & Evaluation. Describe its investigations and management. ★
- Q4Define Approach to a Child with Developmental Delay. Describe its aetiology, causes, investigations and management. ★
- SN1Write a short note on Laws & Patterns of Growth. ★
- SN2Write a short note on Growth Charts. ★
- SN3Describe the tanner Staging of Sexual Maturity Rating. ★
- SN4Write a short note on Primitive (Neonatal) Reflexes. ★
- SN5Write a short note on Anthropometry & Nutritional Classifications.
- SN6Describe the warning Signs of Developmental Red Flags. ★
- SN7Write a short note on Adolescence & Puberty.
- SN8Write a short note on Anterior Fontanelle — Clinical Importance.