- Clinical science
Neurological examination
Summary
Neurological examination is the assessment of mental status, cranial nerves, motor function, sensory function, coordination, and gait for the diagnosis of neurological conditions. Findings should always be compared with the contralateral side and upper limb function should be compared to lower limb function to determine the location of the lesion. This learning card provides information about several examination methods and explains a selection of neurological terms used in the evaluation of neurological conditions.
Mental status examination
Levels of consciousness
- Types of impaired consciousness
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Somnolence
- A state of drowsiness from which a patient can be easily aroused.
- Patient responds normally except for a slight delay when addressed.
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Stupor
- A state of insensitivity bordering on unconsciousness; from which the patient is not easily awoken except if exposed to strong external stimuli; (e.g., if addressed in a loud voice) and into which the patient returns in the absence of further stimuli.
- Communication is not possible and painful stimulus provokes withdrawal response.
- Coma: Patient cannot be aroused and there is no response to stimuli.
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Somnolence
- Glasgow Coma Scale (GCS) quantifies the degree of impaired consciousness
Mental status examination
- Full mental status examination components include:
- Appearance (e.g., groomed, well dressed)
- Behavior (e.g., cooperative, agitated)
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Speech: E.g.,
- Mutism: an inability or unwillingness to speak despite the faculties of speech being intact
- Akinetic mutism: characterized by decreased motor responses and paucity of speech
- Abulia: milder form of akinetic mutism that is characterized by disinterest and a slowed mental state.
- Orientation to person, place, and time
- Mood and affect (as well as congruency)
- Thought content (e.g., delusional) and process (e.g., logical thinking)
- Memory (e.g., short-term vs. long-term memory, assessed by asking the patient to recall a number of objects immediately and again after a few minutes)
- Ability to perform simple calculations (e.g, simple multiplication; determine if appropriate for level of education)
- Insight and judgement (ask patient what they would do in a realistic situation, e.g., if they found a stamped envelope)
- Higher cortical function (e.g., ask patients to explain the meaning of well-known idioms)
- Determine levels of consciousness
- Mini-mental status examination (MMSE)
- Saint Louis University Mental Status Examination (SLUMS)
Findings
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Hemineglect
- Inability to respond to unilateral stimuli due to a brain lesion (not due to a primary motor or sensory lesion)
- The lesion is usually contralateral to the stimuli
- Motor neglect
- Sensory or perceptual neglect
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Amnesia: loss of memory (e.g., time, content)
- Retrograde amnesia: loss of memory-access to events that occurred and/or information acquired prior to the incident
- Anterograde amnesia: loss of memory-access to events that occurred and/or information acquired after the incident
- Global amnesia: loss of memory-access to events that occurred and/or information acquired prior and after the incident
- Aphasia: Inability to communicate (impairment of the ability to either form or understand language)
Location of lesion | Clinical features | ||
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Broca aphasia (motor aphasia, expressive aphasia) | Broca area (frontal lobe) |
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Wernicke aphasia (sensory aphasia, receptive aphasia) | Wernicke area (temporal lobe) |
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Global aphasia | Broca area, Wernicke area, and arcuate fasciculus |
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Conduction aphasia (associative aphasia) | Arcuate fasciculus of the parietal lobe |
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Anomic aphasia | Usually, pinpointing the localization of the lesion is not possible. |
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Transcortical aphasia | Transcortical motor aphasia | Supplementary motor area (SMA) in the cortex, with Broca area intact (exception: may occur during recovery phase of Broca aphasia) |
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Transcortical sensory aphasia | Various areas of the temporal lobe, with Wernicke area intact |
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Apraxia: difficulty performing targeted, voluntary movements despite intact motor function
- Ideomotor apraxia: difficulty imitating actions; intended expression and gestures do not match
- Ideational apraxia: difficulty completing multistep actions.
- Visual motor apraxia: difficulty picking up objects placed in the contralesional visual field.
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Agnosia: Impairment of recognition of sensory stimulus (most commonly visual) [1]
- Tactile agnosia (astereognosis): Impaired ability to recognize or identify objects by touch alone; visual recognition is unimpaired.
- Visuospatial dysgnosia: inability to orient oneself in space
- Prosopagnosia: inability to recognize familiar faces
- Autotopagnosia
- Anosognosia: inability to recognize one's own neurologic impairment
- Pure alexia: form of visual agnosia with severe reading problems, as a result of interrupted connections between the visual cortex and language‑related areas.
- Acalculia: inability to perform simple calculations (parietal lobe lesion)
- Agraphia: inability to write
References:[2][3][4]
Cranial nerve examination
For information on disorders of the cranial nerves, see cranial nerve palsies.
Cranial nerve | What is examined? | How is the test performed? | |
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Olfactory nerve | I | Olfaction |
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Optic nerve | II | Visual acuity |
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Visual field |
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Pupillary light reflex |
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Papilla |
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Oculomotor nerve, trochlear nerve, abducens nerve | III, IV, VI | Eye movement |
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Visual accommodation |
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Eyelid ptosis (Levator palpebrae superioris muscle dysfunction) |
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Trigeminal nerve | V | Facial sensation | |
Muscle function (muscles of mastication) |
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Reflexes |
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Facial nerve | VII | Motor function (muscles of expression) |
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Sense of taste |
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Vestibulocochlear nerve | VIII | Hearing |
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Glossopharyngeal nerve and vagus nerve | IX, X | Palatal movement |
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IX only: sense of taste |
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X only (recurrent laryngeal nerve): vocalization |
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Accessory nerve | XI | Trapezius muscle and sternocleidomastoid muscle (motor function) |
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Hypoglossal nerve | XII | Tongue muscles (motor function) |
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References:[3]
Motor function
Upper motor neuron (UMN) injury vs. lower motor neuron (LMN) injury | ||
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Upper motor neuron lesion (UMN damage) | Lower motor neuron lesion (LMN damage) | |
Definition |
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Muscle appearance |
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Characteristics |
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Bladder function | ||
Special tests |
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Common etiologies |
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Muscle appearance
- Assessment: inspection and palpation of muscle groups
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Findings
- Fasciculation: involuntary, asynchronous contraction of muscle fascicles within a single motor unit; usually benign but can signify a lower motor neuron lesion
- Tenderness
- Abnormal movements (e.g., tremor, tic, myoclonus)
- Abnormal posture
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Atrophy or hypertrophy (examined bilaterally)
- Muscle groups are measured to compare specific differences in size.
- In neurologic disorders, the small hand muscles are often affected by atrophy.
References:[3]
Power
- Definition: maximal effort a patient is able to exert from an individual muscle or group of muscles
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Assessment
- The patient is asked to flex and extend extremities against resistance
- Muscle power tests should be performed bilaterally for comparison
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Muscle power grading
- 0 = no contraction (paresis)
- 1 = flicker or trace of contraction
- 2 = active movement, with gravity eliminated
- 3 = active movement against gravity
- 4 = active movement against gravity and resistance
- 5 = normal power
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Patterns of paresis distribution:
- Quadriparesis: weakness in all four limbs
- Hemiparesis: weakness in half of the body
- Paraparesis: weakness affecting both upper or both lower extremities
- Monoparesis: paresis affecting a single limb
References:[5]
Reflexes
Tendon reflexes
- Definition: stretch, monosynaptic reflexes
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Assessment
- During reflex testing, the patient should be relaxed (at least the muscles involved in the reflex test should be relaxed). (→ also see: radiculopathy)
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Elderly patients may have reduced or absent lower deep tendon reflexes due to normal aging-related changes in muscles and tendons
- A reflex to test the integrity of a sensory and motor neuron circuit
- Upon tapping of the reflex hammer, activation of the dorsal root ganglion causes firing of the lower motor neuron for the agonist muscle and relaxation of the antagonist muscle, resulting in automatic movement.
- An increased DTR indicates an upper motor neuron issue, whereas decreased DTR indicates a LMN, neuromuscular junction, or muscle issue.
Nerve root | Tendon reflex | Test | |
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Upper limbs | C5–C6 | Biceps reflex | First, the examiner places his/her thumb on the patient's biceps tendon, then the examiner strikes his/her thumb with a reflex hammer and observes the patient's forearm movement. |
Brachioradialis reflex | Striking the lower end of the radius with a reflex hammer elicits movement of the forearm. | ||
C7–C8 | Triceps reflex | The examiner holds the patient's arm (forearm hanging loosely at a right angle) and taps the triceps tendon with a reflex hammer to induce an extension in the elbow joint. | |
This reflex is induced by tapping the terminal phalanx of a relaxed finger on the palmar side, while the examiner holds the patient's hand in level with the proximal phalanges. The test is positive when there is significant flexion in the terminal phalanx of the tapped finger and the thumb, or when the flexion is very asymmetrical comparing both hands. | |||
Lower limbs | L2–L4 | Adductor reflex | Tapping the tendon above the medial condyle of femur elicits the adductor reflex. |
Knee reflex | Striking the tendon just below the patella (leg is slightly bent) induces knee extension. | ||
L5 | Posterior tibial reflex | The tibialis posterior muscle is tapped with a reflex hammer, either just above or below the medial malleolus. The reflex is positive when an inversion of the foot occurs. | |
S1–S2 | Ankle reflex | Striking the Achilles tendon with a reflex hammer elicits a jerking of the foot towards its plantar surface. Alternatively, the reflex is triggered by tapping the ball of a foot from the plantar side. |
Superficial reflexes
- Definition: polysynaptic reflexes elicited by stimulation of the skin
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Superficial reflexes are divided into two subgroups:
- Physiological reflexes
- Pathological superficial reflexes: in case of central motor neuron damage, the reflex response decreases.
Nerve root | Reflex | Test |
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T6–T12 | Abdominal reflex | Abdominal reflexes are tested with the patient lying down. The anterior abdominal wall is lightly stroked with a spatula from lateral to medial (bilaterally) in following areas:
A normal response is a contraction of the abdominal muscles, while the absence of contractions is indicative of nerve root damage. |
L1–L2 | Cremasteric reflex | The reflex is elicited by stroking the medial, inner part of the thigh. A normal response is a contraction of the cremaster muscle that pulls up the testis on the same side of the body. |
S3–S5 | Stroking the skin around the anus with a spatula elicits the anal reflex, which results in a contraction of the anal sphincter muscles. | |
Bulbocavernosus reflex | The reflex is elicited by squeezing the glans penis or clitoris, resulting in contractions of the pelvic floor muscles. |
Primitive reflexes
- Brief description: Reflexes that are are normal in newborns and infants, but not in adults, where they may appear in case of diffuse brain injury due to lack of common inhibiting factors
Test | |
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Sucking reflex | Stroking the mouth induces sucking activity. |
Palmar grasp reflex | Stroking the palms elicits finger flexion. |
Palmomental reflex | Stroking the ipsilateral thenar eminence from proximal to distal induces a short involuntary contraction of the mentalis muscle. |
Corticospinal tract signs
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Brief description
- Corticospinal tract signs are indicative of damage to the pyramidal tract.
- Babinski sign is the most common and thus most reliable pyramidal tract sign.
- These reflexes occur physiologically in healthy infants
Test | Sign | |
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Babinski sign | The examiner strokes the sole of a patient's foot on the lateral edge using, e.g., the handle of a reflex hammer | The sign is positive (pathological) when the big toe extends (dorsiflexes), while the other toes fan out. The test is inconclusive when only the big toe responds. |
Gordon sign | The examiner compresses the calf muscles |
Babinski sign, although normal in newborns and infants, is always pathological in adults!
Do not confuse clonus with myoclonus! Myoclonus is arrhythmical and defined by sudden jerks of a muscle or group of muscles while clonus is rather rhythmic and defined by repetitive contractions and relaxations of a muscle group!
Tone
- Definition: resistance of an individual muscle (or a group of muscles) to passive stretching
- Assessment: passive movement of the extremities
Tests | ||
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Upper limb | Lower limb | |
Tone |
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Spasticity |
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Rigidity |
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Clonus |
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Sensation
Pathway | Assessment | Finding | |
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Light touch |
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Pain and temperature |
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Pallesthesia (vibration sense) | A tuning fork is hit and placed on a bony projection (e.g., medial malleolus).
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Proprioception (joint position) |
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- See also “Overview” in incomplete spinal cord syndromes.
References:[3][6]
Coordination
- Definition: ability to coordinate fluid movements
- Assessment
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Findings
- Dysmetria
- Dysdiadochokinesia
- See also cerebellar syndromes.
References:[3]
Gait assessment
- Evidence for vestibular disorders, sensory or cerebellar ataxia (see “Diagnostics” in cerebellar syndromes)
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Assessment
- Observation of casual gait: The patient is asked to walk a few steps forwards and backwards.
- Normal gait: steady, natural arm swing
- Abnormal gait: broad-based or unsteady gait, short-stepping gait
- Balance test: The patient is asked to place one foot directly in front of the other as if walking on a tightrope
- Foot drop test: The patient is asked to walk on their heels (impossible in the case of deep fibular nerve lesions)
- Walking on tiptoes (impossible in the case of tibial nerve lesions)
- Observation of casual gait: The patient is asked to walk a few steps forwards and backwards.
Description | Examination | Result | |
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Romberg test |
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Unterberger test |
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Trendelenburg sign |
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Signs of meningeal or nerve root irritation
Meningism
- Definition: triad of nuchal rigidity; , headache, and photophobia, associated with irritation of the inflamed meninges and/or spinal nerves
- Examination: The examiner passively flexes the neck of the patient lying in the supine position.
- Causes: subarachnoid hemorrhage (SAH), bacterial meningitis, etc.
Additional signs of meningeal or nerve root irritation
- Straight leg raise test (root L5–S1)
- Kernig sign: : in a supine patient, painful passive extension of the knee when the thigh is flexed at the hip (knee at a 90° angle)
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Brudzinski sign
- Involuntary lifting of the legs provoked by passive flexion of the neck in a patient in supine position
- Lifting of the legs reduces pain associated with tension of the irritated meninges and, especially, the lumbosacral spinal nerves during neck flexion