Overview
This lecture outlines the five-minute neurological examination, summarizes its components and order, and explores methods for efficient lesion localization, diagnosis, and interpretation of neurological findings.
Purpose and Approach to Neuro Exam
- The primary goal of the neurological exam is to localize the lesion within the nervous system.
- Observing the patient’s speech, movement, and interaction is crucial for localization.
- Overly detailed exams without focus can obscure diagnosis and waste time.
Components of the Five-Minute Neurological Exam
- Mental Status: Assess cognition and language mainly during history taking; naming is tested separately.
- Cranial Nerves: Test visual fields, pupils, eye movements, facial symmetry, and lower cranial nerves if symptoms like dysphagia exist.
- Motor Examination: Observe involuntary movements, perform pronator drift and external leg rotation, assess tone and functional strength.
- Sensory Examination: Focus testing to symptoms; check sensory level and proprioception (Romberg test for proprioception, not cerebellar function).
- Coordination: Evaluate ataxia, test truncal stability for cerebellar vermis lesions.
- Reflexes: Assess objectively for asymmetries; Babinski sign should not be over-interpreted.
- Gait: Inspect base, stride, arm-swing, turning, and symmetry.
Suggested Order of the Exam
- Begin with mental status, adventitial movements, facial symmetry.
- Assess various gaits, truncal stability, Romberg test.
- Test upper/lower limb function (e.g., rising from squat, raising arms).
- Check visual fields, pupils, eye movements.
- Formal motor and sensory testing, followed by reflexes.
Diagnostic Principles
- Anatomic diagnosis: Localizes lesion (central or peripheral structures).
- Etiologic diagnosis: Determines cause based on history and time course (e.g., stroke, tumor, demyelination, degeneration).
Key Elements of Neurologic History
- Identify chief complaint and onset pattern (sudden, subacute, chronic, remitting).
- Gather complete medical, medication, psychiatric, family, social, and occupational history.
- Interview surrogate historians for patients with cognitive impairment or altered mental status.
Mental Status Testing
- Includes alertness, focal cortical functions (aphasia, apraxia, agnosia), cognition, mood/affect, and thought content.
- Cognitive tests: orientation, memory, intellect, abstraction, judgment.
Examination of Major Neurological Systems
- Skull/Spine: Inspect for trauma, tenderness, ROM, and signs of meningeal irritation (Brudzinski/Kernig signs).
- Cranial Nerves: Sequentially assess all 12 nerves, paying attention to sensory, motor, and reflex functions.
- Motor System: Evaluate muscle bulk, spontaneous movements, tone, and strength (both functional and formal testing).
- Sensory System: Test protopathic (pain/temp), epicritic (vibration/position), and cortico-sensory modalities (stereognosis, two-point discrimination, graphesthesia).
- Coordination: Assess truncal and limb coordination (finger-to-nose, heel-to-shin, diadochokinesia).
- Reflexes: Muscle stretch (deep tendon) and superficial reflexes; Babinski sign and frontal release signs for pathology.
- Gait and Station: Evaluate for asymmetry and ataxia using different walking and standing tasks.
Lesion Localization
- Distinguish upper vs. lower motor neuron lesions using clinical findings (e.g., tone, reflexes, Babinski sign).
Key Terms & Definitions
- Aphasia — Language disorder due to dominant hemisphere lesion.
- Agosia — Inability to recognize sensory stimuli with normal sensation.
- Apraxia — Inability to carry out learned movements despite normal motor/sensory systems.
- Pronator Drift — Subtle pronation of outstretched arm, indicating UMN dysfunction.
- Romberg Test — Assesses proprioception; positive if balance lost with eyes closed.
- Babinski Sign — Upgoing big toe after foot stimulus, suggests UMN lesion.
- Clonus — Repetitive muscle contractions after stretch, indicates hyperreflexia.
- Tandem Gait — Heel-to-toe walking for gait assessment.
- Functional Strength Testing — Real-world tasks to assess muscle strength.
Action Items / Next Steps
- Practice the five-minute neurological examination in real or simulated patient encounters.
- Review diagnostic tables and abnormal findings for rapid reference.
- Study additional resources on neuroanatomy and lesion localization, as suggested in lecture materials.