Sensory Disturbances

How to Cite This Chapter: Oczkowski W, Bodzioch M. Sensory Disturbances. McMaster Textbook of Internal Medicine. Kraków: Medycyna Praktyczna. Accessed May 22, 2024.
Last Updated: November 4, 2021
Last Reviewed: November 4, 2021
Chapter Information

Causes and PathogenesisTop

Sensory disturbances may present as either or both of sensory decrease (negative symptoms; eg, impairment or loss of one or more types of sensory perception) and positive symptoms (eg, abnormal sensory perception in the form of paresthesia [pins and needles] or hypersensitivity to sensory stimuli [hyperesthesia and/or pain]).

Causes: Conditions that damage peripheral receptors located in various tissues and organs, sensory fibers in peripheral nerves, ascending tracts in the spinal cord or brainstem, the thalamus, or cortical centers in the parietal lobe.

Sensory disturbances can occur separately but can also be associated with motor weakness or other neurologic signs that help identify the location of the disturbance (eg, lower motor neuron signs, such as hypotonia and loss of reflexes, suggest a peripheral nerve dysfunction; see Muscular Weakness (Paresis and Paralysis)). The presence of pain suggests irritation of a peripheral nerve, plexus, nerve root, or dorsal horn ganglion as the location of the sensory disturbance.

Patterns and causes of specific types of sensory symptoms based on the location of nervous system lesions: Table 1. Brief and transient paresthesias are not suggestive of nervous system damage.


1. History and physical examination: Determine the type and severity of sensory symptoms, location and distribution of sensory abnormalities, and circumstances in which they have occurred. The sense of touch is examined by touching the patient’s body with your finger or cotton swab. The sense of pain is examined with a sharp pin. The sense of temperature is examined with a cold and hot object. The sense of vibration is examined with a 128 Hz tuning fork. The sense of position is examined by moving a joint. When examining for sensory abnormalities, compare the symmetric parts of the body, precisely determine the boundaries of sensory abnormalities, compare them with the areas of innervation by specific peripheral nerves and with dermatomes (Figure 1), compare them with the patterns of sensory loss based on the location of the lesion (Table 1), and identify associated motor or pathognomonic signs (see Muscular Weakness (Paresis and Paralysis)).

2. Diagnostic studies: Imaging studies (computed tomography [CT], magnetic resonance imaging [MRI]) of the brain or spinal cord (or both) as well as electrophysiologic tests (sensory conduction, somatosensory evoked potentials), depending on the suspected location of the lesion.

Tables and FiguresTop

Table 1.35-1. Manifestations and causes of sensory abnormalities based on the location of the lesion

Lesion location

Pattern of sensory disturbances

Possible causes

Peripheral nerve

Pain and paresthesia in area innervated by affected nerve followed by sensory loss involving all sensory functions

Mononeuropathy (compression, injury)

Nerve root

Pain worsened by activities increasing intraspinal pressure (eg, cough, defecation), paresthesia within areas innervated by respective nerve roots followed by sensory loss involving all sensory functions

Radiculopathy (disc herniation, acute inflammatory demyelinating polyradiculopathy, severe degenerative lesions of spine, tumor)

Spinal cord lesion

– Sensory loss below lesion level

– Hemicord syndrome: ipsilateral loss of vibration and position sense with contralateral loss of pain and temperature sense

Trauma, tumor, demyelination, infection, ischemia or hemorrhage, of spinal cord

Anterior spinal artery syndrome

Sensory loss below lesion level, dissociated sensory loss: loss of pain and temperature with preserved vibration and position sense (with paralysis)

Anterior spinal artery thrombosis

Posterior columns of spinal cord

Loss of vibration and position sense with preserved pain and temperature (with loss of reflexes)

Subacute combined degeneration of spinal cord (in vitamin B12 deficiency), tabes dorsalis (neurosyphilis)

Trigeminal nerve or nucleus

Sensory loss in face in distribution of the trigeminal nerve or branches

Inflammation, demyelination, tumor

Thalamus or posterior limb of internal capsule

Sensory loss of pain and temperature on contralateral side of face, arm, and leg, including trunk; chronic thalamic pain syndrome may occur later

Ischemic or hemorrhagic stroke, tumor, demyelination

Parietal cortex

Inability to assess stimulus intensity and location, impaired graphesthesia (ability to recognize letters or numbers traced on skin), loss of 2-point discrimination (ability to recognize 2 simultaneously applied stimuli as separate), extinction (inability to recognize 1 of 2 simultaneously applied tactile stimuli on symmetric body regions), astereognosis (inability to recognize objects held in hand without visual inspection)

Ischemic or hemorrhagic stroke, tumor

Figure 1.35-1. Segmental innervation of the skin and cutaneous fields of peripheral nerves.

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