Editors

EsaMervaala

MariAuranen

Peripheral Neuropathies: Examination of the Patient

Determine the level of the disorder: is there
- specifically a disorder of the peripheral nerve system
- only one damaged nerve, i.e., mononeuropathy
- a more extensive peripheral nerve disorder, i.e., polyneuropathy.
The symptoms can be motor, sensory, autonomic or all these together.
Many neuropathies are caused by a systemic disease, the most common causes being diabetes and excessive consumption of alcohol.

Motor symptoms:
- Weakness, fatigue, cramps, fasciculations (muscle twitches i.e. myokymia Eyelid Myokymia).
Sensory symptoms:
- Sensory deficits, dysaesthesia, pain, burning sensation, ataxia.
Autonomic nerve system symptoms:
- Postural hypotension
- Disturbances in the gastrointestinal tract, urinary tract, or perspiratory function
- Erectile dysfunction

Quick diagnostics of peripheral nerve disorders: see table T1
Muscle weakness or atrophy
Sensory deficits and dysaesthesia for all sensory modalities
- Touch
- Pain
- Vibration
- Joint position
Weak or absent tendon reflexes, weakened muscle tone
Skin ulcerations due to nerve damage
- Caused by insufficient provision of nutrients and oxygen in the tissues
Clinical findings indicating abnormalities in the autonomic nerve system
- Pupillary size abnormalities and/or reduced response to light
- Dry socks (anhidrosis)
- Palpitations
- Postural hypotension

Nerve	Impairment	Atrophy	Sensory impairment
Note: Exaggerated reflexes, spasticity, clumsiness and pareses and sensory impairment not consistent with peripheral nerve or root territories indicate a disorder of the central nervous system.
Medianus	Opposition of the thumb	Thenar	Palmar side of fingers I-III (IV)
Radialis	Extension of wrist and fingers	Radial side of forearm	Dorsal side of the hand, base of thumb
Ulnaris	Adduction and abduction of fingers	Interosseal, hypothenar muscles	Little finger and ulnar side of ring finger (IV)
Femoralis	Extension of knee, straight leg lifting	Quadriceps femoris muscle	Front thigh
Peroneal	Extension of toes and foot (weakness when standing on heels)	Anterior tibial muscle (tibial bone "sharp")	Lateral side of leg, base of toes l-ll
Tibial	Extension of ankle (weakness when rising on toes)	Small plantar muscles	Calf, sole of foot, toes III-V
Lateral cutaneous femoral	-	-	Lateral anterior surface of thigh

See Polyneuropathies
Most common presentation: sensorimotor, characterised by ascending and symmetrical distal dysaesthia ("sock-and-glove" type), muscle weakness, muscle fatigue, and diminished tendon reflexes.
Exclusively sensory or motor polyneuropathies are rare.
Aetiology: see Polyneuropathies

Two or more nerves in several extremities are damaged (e.g. n. ulnaris and n. peroneus)
The classic manifestation is associated with periarteritis nodosa and collagen diseases as well as diabetes. Has also been described in association with Sjögren's syndrome and as a paraneoplastic phenomenon.

Certain mononeuropathies are typical of certain aetiologies.
- Paresis of the femoral nerve and the oculomotor nerve: diabetes
- Paresis of the facial nerve: sarcoidosis, borreliosis
See also Nerve entrapment and compression disorders Nerve Entrapment and Compression Disorders.

In acute disorders of the upper motoneuron, tendon reflexes may be initially weaker, but later increased, and the muscle tone may be increased. The patient may also present with other indications of damage related to the brain Cerebral Infarction (Ischaemic Stroke) Radiculopathies or the spinal cord Diseases of the Spinal Cord.
In muscle disorders Hereditary Myopathies and motoneuron disorders (ALS Amyotrophic Lateral Sclerosis (ALS)) dysaesthesia is not present.
Diseases of the musculoskeletal system (arthritis, osteoarthritis, tendinitis, etc.) are not associated with reflex changes or dysaesthesia. Joint or tendon pain is a frequent presentation.
Polyradiculitis Guillain-Barré Syndrome (Polyradiculitis) is a disease of the peripheral nerves with rapid and severe progression, which is why it must be identified.