Meralgia paraesthetica

Classification according to ICD-10
G57.1	Meralgia paraesthetica inguinal tunnel syndrome
ICD-10 online (WHO version 2019)

Meralgia paraesthetica (also inguinal tunnel , inguinal tunnel or Bernhardt-Roth syndrome ) is a nerve compression syndrome of the lateral femoral cutaneous nerve in the area of ​​the inguinal ligament .

Meralgia paraesthetica is an isolated narrowing (compression) of the purely sensitive lateral cutaneous femoral nerve . This nerve originates from the lumbar plexus and leaves the pelvis close to the anterior superior iliac spine and penetrates here through the fibers of the inguinal ligament, where it can be easily narrowed. One then speaks of the inguinal tunnel syndrome, which is the third most common bottleneck syndrome.

causes

The causes of meralgia paraesthetica are often mechanical pressure under the inguinal ligament or pressure or tension effects in the course of the nerves, v. a. to be found at the point of exit from the pelvis (compression syndrome). However, a lesion of the nerve as a complication of medical measures is not uncommon as a cause (for example, through removal of bone grafts or iliac crest puncture, rarely also after opening the abdominal wall, e.g. as part of a complicated appendectomy or hip joint operations).

Meralgia paraesthetica affects men three times as often as women.

The triggers for mechanical pressure typically include:

• Direct pressure from tight clothing (e.g. jeans ) or seat belts ( seat belt syndrome )
• pregnancy
• Weight gain (pot belly)
• Weight loss (lack of fat pad)
• Mechanical irritation from strength training around the groin, especially the thigh muscles and abdominal muscles
• Incorrect pelvic posture due to imbalance between back and abdominal muscles

The non-mechanical cause can be mononeuropathy in the context of diabetes mellitus .

Symptoms

Radiation of pain in Meralgia paraesthetica

The patients complain of burning, possibly pinprick-like pain and abnormal sensations on the anterior outer thigh. In the beginning these occur mainly when standing for a long time or when the hip joint is extended for a long time (e.g. lying on the back). The skin becomes overly sensitive, so that even clothing can hardly be endured. Pain can occur more often at night (meralgia paraesthetica nocturna) when the leg is fully extended. It can also lead to a loss of sensitivity, which manifests itself as a partial numbness of the skin in the affected and surrounding area.

Later on there are vegetative disorders , for example reduced hair growth in the area supplied by the nerves ( hypotrichosis ) and thinning of the skin. The sensitivity worsens and can eventually remain permanently disturbed, although the paresthesia persist.

It is typical that the abnormal sensations improve with hip flexion. Conversely, they can be provoked by overstretching the hip joint while bending the knee in the side position. In 2/3 of the patients there is a painful point just medial to the anterior superior iliac spine .

It is noteworthy that there is no motor impairment, which distinguishes meralgia paraesthetica from radiculopathy .

treatment

It is important to find out the possible cause and to tailor the therapy individually to the needs of the individual affected. Early therapy makes sense because the chances of recovery worsen with the duration of nerve damage. Avoiding tight clothing or stretching the hip joint can help. In a large number of those affected, the symptoms recede spontaneously once the triggering factor has been eliminated.

Surgical decompression or cutting of the nerves is possible (freedom from pain in about 80% of patients), but in some cases the pain can worsen.

Medicinal pain treatment

Acute and subacute non-steroidal anti-inflammatory drugs can be tried, otherwise pyrimidine nucleosides, baclofen (a muscle relaxant active in the brain / spinal cord) and, in the case of more paroxysmal (attack-like) pain, carbamazepine , gabapentin or pregabalin . Carbamazepine (gabapentin, pregabalin) can be combined with baclofen to save active ingredients (e.g. in the event of excessive side effects).

Special pain therapy

Therapeutic local anesthesia (treatment with a local anesthetic or local anesthetic) for meralgia paraesthetica: Repeated nerve blocks / anesthesia of the lateral femoral cutaneous nerve with 5–8 ml bupivacaine 0.25% in the angle between the anterior superior iliac spine and the inguinal ligament. In stubborn cases, continuous 3-in-1 blockade using a femoral nerve catheter. Pharmacologically, therapy with antineuropathic drugs such as anticonvulsants (e.g. pregabalin) or antidepressants (e.g. amitriptyline) is recommended.

literature

• M. Bernhardt: Over isolated in the area of ​​the N. cut. fem. ext. occurring paresthesias. In: Neurological Centralblatt. 1895, No. 6.
• WK Roth: Meralgia paresthetica. S. Karger, Berlin 1895.
• GK Ivins: Meralgia paresthetica, the elusive diagnosis: clinical experience with 14 adult patients. In: Ann Surg . 2000 Aug; 232 (2), pp. 281-286. PMID 10903608

Individual evidence

1. ↑ DR Durbin, KB Arbogast, EK Moll: Seat belt syndrome in children: a case report and review of the literature. In: Pediatr Emerg Care. 2001 Dec; 17 (6), pp. 474-477. PMID 11753199
2. ^ JM Pearce: Meralgia paraesthetica (Bernhardt-Roth syndrome). In: J Neurol Neurosurg Psychiatry. 2006 Jan; 77 (1), p. 84. PMID 16361600 .

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !