How is the cause of paraesthesia diagnosed

What is actually behind ... Paresthesia?

Everyone has probably "fell asleep" with an arm or foot. When arteries are squeezed and the nerves run out of oxygen, "the nerves go to sleep": They no longer report anything. When they are supplied with blood again, they initially malfunction and the nerves report the typical tingling sensation.

If pain sensations are in the foreground, one speaks of dysesthesia, with reduced sensitivity of hypesthesia and with increased sensitivity to touch or temperature of hyperesthesia.

Acute paresthesias are often harbingers of severe disorders in the CNS, e.g. B. apoplexy or focal seizures. The diagnosis is then revealed in the context of the overall clinical picture. Chronic paresthesias are much more common and at the same time more difficult to classify diagnostically.

Fingers, hands and arms

In the upper extremities, bottleneck syndromes are the dominant cause of chronic paresthesia, while internal diseases play a less common role. The narrow points are in the hand area, but also in the elbow, in the cervical spine or in the neck and chest muscles.

Carpal tunnel syndrome (KTS, CTS). Carpal tunnel syndrome is the most common upper extremity bottleneck syndrome and is the result of compression of the median nerve in the wrist. Paraesthesias occur mainly at night in the thumb, index finger and middle finger as well as on the radial side of the ring finger and sometimes radiate into the shoulder. Symptoms usually get better with lowering the arms and shaking and massaging the hand. The ball of the thumb may later atrophy. The trigger is often an overload due to one-sided activities. Secondarily, it occurs after bone fractures, tendonitis and rheumatic diseases.

Ulnar tunnel syndrome (Guyon tunnel syndrome). Here the ulnar nerve is compressed in the Guyon box on the wrist. The syndrome is also known as "cyclist's paralysis" because it often occurs as a result of incorrectly positioning the hands on the bicycle handlebars. According to the supply area of ​​the ulnar nerve, paresthesias are found particularly on the ring and little fingers. Over time, the ball of the little finger atrophies, ring and little fingers bend (claw hand).

Sulcus ulnaris syndrome (Cubital Tunnel Syndrome). At the elbow, the ulnar nerve runs in a groove (sulcus nervi ulnaris), through the so-called cubital tunnel (Latin cubitus = elbow). Compressions of the ulnar nerve in this area occur v. a. after injuries and also lead to pain in the forearm and hand.

Cervical spine syndrome (Cervicobrachial syndrome). Feelings of numbness in the fingers and hands are not infrequently the result of whiplash, herniated discs or osteoarthritis. Depending on the damaged nerve, different areas of the hand are affected.

Polyneuropathies. In addition to nerve bottleneck syndromes, internal diseases also lead to sensitivity disorders. Polyneuropathies are most often found in diabetes and chronic alcohol abuse, less often in infections, poisoning or vitamin B deficiency, v. a. Vitamin B12 -Defect. Then the symptoms also affect the lower extremities and, in addition to the skin, other organs, e.g. B. in diabetes the stomach.

Circulatory disorders. Raynaud's syndrome is a vascular disease with paroxysmal vasospasms. a. in the fingers, almost never in the thumbs or toes. Triggered by cold or emotional stress, the fingers suddenly turn white, usually starting from the fingertips. Such an attack is usually accompanied by pain, numbness and tingling. The attacks almost always last only a few minutes and subside without further damage. Only in secondary Raynaud's syndrome, e.g. B. after trauma or rheumatic diseases, necrosis of the fingertips (rat bite necrosis) can occur.

Arterial circulatory disorders rarely play a role in paresthesia of the hands.

Legs and feet

Alcoholic and diabetic polyneuropathy and circulatory disorders dominate the lower extremities as causes of paresthesia. Bottleneck syndromes are rare except for the herniated disc.

Polyneuropathy. Alcohol abuse and diabetes are common causes, while others are rare. The sock-shaped, symmetrical expansion is typical. Dysesthesia ("burning feet") and loss of deep sensitivity are also common. Hypesthesia in the foot area is particularly critical, with the risk of injuries and infections.

Peripheral arterial disease (PAD). Smokers and diabetics are particularly affected. Characteristic are symptoms when walking, which subside when standing still (intermittent claudication, intermittent claudication). Early therapy is important to avoid ulcers and gangrene.

Tarsal tunnel syndrome. The tibial nerve supplies the flexor muscles of the lower leg and the muscles of the sole of the foot. It runs through the tarsal tunnel behind the inner ankle. The cause can be misalignment, overload or injuries. Paresthesia occur v. a. at night and under stress on the inner edge of the foot. Pain may radiate into the soles of the feet and calves.

Inguinal tunnel syndrome (Meralgia paraesthetica). Obesity, pregnancy or tight jeans compress the lateral femoral cutaneous nerve in the groin and cause discomfort on the anterior outer surface of the thigh.

therapy

Therapy of the cause, e.g. B. Stroke or herniated disc is in the foreground in acute paresthesias. In compression syndromes, the affected nerve is relieved by immobilization or surgery. Physiotherapy helps in some cases.

In the case of circulatory disorders and alcoholic or diabetic polyneuropathies, it is important to minimize the risk factors. For diabetics, the most effective measure is good blood sugar control.

In addition to preventive measures, rheological and pain-relieving measures are taken:

  • Vascular training
  • Antiplatelet agents, e.g. B. acetylsalicylic acid, clopidogrel
  • without guaranteed effect: alpha lipoic acid
  • for neuropathic pain: gabapentin, pregabalin
  • Antidepressants, e.g. B. amitriptyline, paroxetine
  • Revascularization (stent, bypass).

With timely therapy, most paresthesias, v. a. in compression syndromes, reversible. In diabetes and PAD, consistent therapy and lifestyle changes, e.g. B. Refraining from alcohol and smoking, ultimately the prognosis.

Paresthesia of the thumb, index finger, middle finger, v. a. at night
  • possibly atrophy of the ball of the thumb
  • possibly radiance in arm to shoulder
Paresthesia on the ring and little fingers
  • possibly atrophy of the ball of the little finger
Pain in forearm and hand
  • Paresthesia on the ring and little fingers
  • possibly atrophy of the little finger ball
Paresthesia of the hand or arm with neck discomfort
Attacks of white fingers with pain, numbness, tingling
  • often triggered by stress or cold
Numbness in your arms or legs with back pain
  • disc prolapse
  • Spinal stenosis, vertebral body fracture
  • Bone tumor of the spine
Stocking-shaped, symmetrical paresthesias, v. a. on lower extremities
  • Loss of deep sensitivity
  • alcoholic polyneuropathy
  • diabetic polyneuropathy
  • rare: hypothyroidism, infections, poisoning, vitamin B deficiency.
Paresthesia and pain
burden
  • cool skin, missing pulses
Paresthesia on the inner edge of the foot, especially during exercise and at night
  • possibly radiation in the sole of the foot, calf
Paresthesia on the front of the outside of the thigh
Increasing numbness for weeks to months
  • possibly with paralysis or pain
  • Brain or spinal cord tumor
  • Collagenosis, e.g. B. Lupus erythematosus
Seizure-like ant running, possibly hiking
Epilepsy with single partial seizures
Drug side effect, e.g. B. of antibiotics, basic anti-inflammatory drugs, chloroquine, cytostatics
Alternating numbness and / or discomfort in the event of negative neurological findings
dissociative or somatoform disorder

SourceMumenthaler, M .; Mattle, H .: Neurology, 20th ed., 2008 Thieme VerlagSchäffler, A. (Ed.): Gesundheit heute, 2nd ed. 2009, Deutscher Apotheker Verlag, Stuttgart
Author: Dr. med. Arne Schäffler & Kollegen, Augsburg, www.schaeffler.cc