Meralgia paraesthetica

Question 1

What is Meralgia paraesthetica?

Answer 1

syndrome of paraesthesia or anaesthesia in the distribution of the lateral femoral cutaneous nerve (LFCN)

Question 2

causes of Meralgia paraesthetica

Answer 2

• entrapment mononeuropathy of the LFCN
• can be iatrogenic after a surgical procedure
• pressure from a neuroma

Question 3

Is the Lateral femoral cutaneous nerve predominantly sensory or motor?

Answer 3

LFCN is primarily a sensory nerve, carrying no motor fibres.

Question 4

From which dermatomal segments does the LFCN originate?

Answer 4

L2/3 segments.

Question 5

Anatomical path of LFCN

Answer 5

• behind the psoas muscle
• beneath the iliac fascia
• crosses the surface of the iliac muscle
• exits through or under the lateral aspect of the inguinal ligament.

Question 6

Where in the path of the LFCN is it subject to repetitive trauma or pressure, causing pain?

Answer 6

around the anterior superior iliac spine (ASIS)

Question 7

Typical demographic

Answer 7

Male>female
Age 30-40
occurs more commonly in those with diabetes

Question 8

Risk factors for Meralgia paraesthetica

Answer 8

Obesity
Pregnancy
ascites
Trauma
Iatrogenic (surgery)
Perthe’s disease.
Some sports

Question 9

Typical presentation

Answer 9

Following symptoms in upper lateral thigh:
Burning, tingling, coldness, or shooting pain
Numbness
Deep muscle ache
Symptoms aggravated by standing, and relieved by sitting

Question 10

Clinical signs on examination

Answer 10

Symptoms reproduced by deep palpation just below the ASIS and by extension of the hip.
Altered sensation over the upper lateral aspect of the thigh.
NO motor weakness.

Question 11

Possible Investigations used

Answer 11

Nerve conduction studies
US if looking to treat with local anaesthetic