Neurological Examination

Essentials

• Obtaining the patient's history is the most important part of a neurological examination, provided that the patient's level of consciousness is normal. By carefully listening to the patient, and asking questions, unnecessary further tests can usually be eliminated.
• If the findings in a basic neurological examination are normal, a significant portion of neurological conditions can be excluded with high probability.
• A neurological examination involves an assessment of both the patient's general status (higher mental functions) (not discussed in detail in this article) as well as the neurological status.
• The examination should always be carried out in the same logical order so as to minimise the possibility of omitting a part of it, for example after being distracted by the patient's questions. All findings should be documented immediately since it can be surprisingly difficult to remember afterwards, for example, which side was affected by a symptom.
• The neurological status helps to establish an anatomical diagnosis, i.e. do the symptoms originate from the
  • brain
  • spinal cord
  • peripheral nervous system
  • neuromuscular system or
  • muscles?
• After the anatomical diagnosis has been made, the examination is focused towards localising more closely the origins of the symptoms within the central or peripheral nervous system. At this stage, particular attention is paid to any asymmetry between sides in the upper and lower extremities.

Other articles covering subsections of a neurological examination

• Unconscious patient An Unconscious Patient
• Examining a patient's gait Gait Disturbances
• Neurological eye symptoms Neurological Eye Symptoms
• Examining a patient's speech Aphasia
• Examining a patient's cognition Neuropsychological Disorders
• Muscle weakness and paralysis symptom Muscle Weakness and Paralysis Symptom

Ocular fundi

• The optic disc, or papilla, should be viewed and its borders examined using an ophthalmoscope. A normal papilla has clear and well-defined borders. Hazy ill-defined borders suggest an increase in intracranial pressure (picture ).
• In the healthy ocular fundi it is exceptionally the veins, not the arteries, that pulsate. If pulsating veins are visible in the middle of the optic nerve, it helps in excluding an increase in the intracranial pressure.

Cranial nerves

• Disorders of the brain stem regions (midbrain, pons, medulla oblongata) can be localised by examining the functioning of the cranial nerve nuclei situated in each region.

1. Olfactory nerve
   • Smell tests (tar, coffee, vinegar, ammonia or commercially available kits)
2. Optic nerve
   • Visual acuity (is the patient able to see a TV screen, count fingers at a given distance, perceive any light)
   • Visual fields (confrontation test, if necessary a referral to an ophthalmologist for the visual field test)
3. Oculomotor nerve
   • Pupillary response, medial eye movements, ptosis, diplopia
4. Trochlear nerve
   • Eye movements: the downward gaze of the eye ipsilateral to the lesion is impaired, diplopia
5. Trigeminal nerve
   • Sensory testing of both halves of the face, each three nerve branches (ophthalmic nerve, maxillary nerve and mandibular nerve) separately.
6. Abducens nerve
   • A lesion will cause ipsilateral gaze dysfunction past the midline, double vision (diplopia).
7. Facial nerve
   • Frowning, wrinkling the nose, whistling and grinning
   • Paresis of the lower half of the face (asymmetry in the oral region) is a sign of a central aetiology.
   • Complete facial paresis (muscle weakness on one side of the face) is a sign of peripheral facial nerve involvement.
8. Vestibulocochlear nerve
   • Vestibular nerve
     • Balance testing
       • In the Romberg's test the patient stands upright with the feet close together, eyes closed and the arms outstretched with palms upwards. Balance problems during the test may also be due to causes other than those originating from cranial nerves.
       • The Unterberger stepping test is conducted with the patient marching on the spot, eyes closed, taking 25 steps with both feet. Possible rotation (over 45°) noted of the body axis will be towards the affected inner ear.
     • Nystagmus can usually be induced in acute vertigo when the eyes follow a moving object.
       • Dix-Hallpike test Benign Paroxysmal Positional Vertigo (BPPV)
     • Note! Nystagmus may also originate from the cerebellum and be due to an inability to follow a moving object.
   • Cochlear nerve: audiometry, Weber's test and Rinne's test
9. Glossopharyngeal nerve
   • Gag reflex
10. Vagus nerve
    • Hoarseness, dysphagia
11. Accessory nerve
    • Shrugging of the ipsilateral shoulder is impaired
    • Impaired head turning against resistance
12. Hypoglossal nerve
    • The patient is asked to protrude his/her tongue in the midline
      • Contralateral tongue deviation is seen in an upper motor neurone lesion.
      • In a lower motor neurone lesion, the tongue deviates towards the affected side.

Co-ordination tests

• Abnormal findings are a sign of a cerebellar lesion
  • Diadochokinesis: impaired ability to perform rhythmically alternating repeat movements.
  • Finger-to-nose and heel-to-knee tests: impaired ability to estimate the range of motion

Pronator drift

• The test is conducted by asking the patient to extend his/her arms at shoulder level with the palms up, eyes closed. The arms are then slowly lowered down simultaneously. One hand falling faster than the other or rotating into pronation is a sign of dysfunction of the pyramidal tract.

Muscle strength

• Often only the strength of the large muscle groups is tested, with the aim of identifying possible asymmetry between the sides. The patient may be asked to press the examiners hands simultaneously with both hands. In addition, the large muscles of the upper and lower extremities are tested separately, with the examiner resisting the patient's extension and flexion movements. The usual way to record the result is to write down whether the patient was able to overcome the examiner's resistance.
• Especially in paralysed patients it is also assessed whether the muscle strength in the extremity is sufficient to overcome gravity and whether the patient is able to keep the extremity in the air unsupported for several seconds. The functions and strengths in the extremities are always compared in pairs between the opposite sides.

Muscle tone

• Spasticity
  • Muscle tone that increases either smoothly during passive movement or occurs as a clasp-knife phenomenon with most resistance felt at the start of movement.
  • A sign of dysfunction of the pyramidal tract
• Rigidity
  • Uniformly increased muscle tone which persists throughout passive movement.
  • In cogwheel rigidity, there is a clear feeling of short, jerky movements when a joint of a relaxed limb is flexed. Most noticeable when the contralateral limb is activated.
  • A sign of an extrapyramidal lesion.

Reflexes

• Reflex hyperactivity or the so-called spread of reflexes (e.g. the patellar reflex is activated while the upper part of the leg is tapped) are signs of dysfunction within the central nervous system whilst diminished reflexes are indicative of lesions within the nerve roots or peripheral nerves.
• A clonic reflex refers to an extremely increased tendon reflex with the muscle contracting rapidly in an oscillating manner (e.g. the rhythmic twitching of the ankle that is ”left on” while the Achilles tendon reflex is tested).
• It is easiest to test the reflexes when the limb is relaxed. This requires a co-operative patient and is not always easy.
• Head region
  • Masseter reflex (jaw jerk reflex): the examiner lightly taps his own index finger, placed on the patient's chin, with a reflex hammer while the patient's mouth is held slightly open. In normal subjects, only a slight mouth closing movement will be noted.
  • Glabellar reflex (glabellar tap sign): repetitive tapping on the space between the eyebrows and above the nose; in normal subjects, initial blinking of the eyes will stop after a few taps.
• Upper limbs
  • Biceps reflex tested at the site of the biceps tendon
  • Triceps reflex tested at the site of the triceps tendon
  • Brachioradialis reflex tested around the styloid process of the radius
• Lower limbs
  • Patellar reflex (knee jerk reflex) tested just under the patella
  • Achilles reflex (ankle jerk reflex) tested at the Achilles tendon with the ankle at dorsiflexion
  • Babinski sign
    • Hallux flexion vs. extension, observed when the outside of the sole is stimulated with a blunt instrument (a pen, the side of a tongue depressor etc.)
    • Extension (upward response of the hallux) is a sign of dysfunction of the pyramidal tract.
      • Do not mix with a normal avoidance reaction that may look like extension.

Sensory system

• Testing is done symmetrically on the face, upper and lower limbs and, if necessary, on the trunk. The origin and type of sensory nerve damage can be revealed by the location and quality of sensory loss.
• Pain and temperature
  • Pain (sharp touch) is tested by using a sharp object (e.g. the tip of a wooden spatula split in half).
  • Temperature can be tested, for example, by using tubes containing warm and cold water.
• Position and vibration
  • Position sense can be tested by turning the patient's toe joints upwards and downwards.
  • Vibration sense is tested with a tuning fork placed over bony prominences of the upper and lower limbs.
• Light touch is tested by gently touching the skin with a cotton wisp or the fingertips.

Autonomic nervous system

• Testing for orthostatic hypotension Brief Orthostatic Test
• Other disorders of the autonomic nervous system are identified in the usual way by evaluating the patient's history (arrhythmia sensations, defecation and urinary functions).