Atlas of Neuromuscular Diseases - part 5 ppt

Lateral pectoral nerve: Receives fibers from C5–7 lateral cord of plexus and supplies upper part of pectoral muscle.. Medial pectoral nerve: Receives fibers from C8/T1 and supplies lower

Thoracodorsal nerve

Genetic testing NCV/EMG Laboratory Imaging Biopsy

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Fig 29 Thoracodorsal nerve

anatomy 1 Thoracodorsal nerve.

2 Latissimus dorsi muscle

Fibers stem from C5–C7 roots (Only 50% of cases have fibers from C7.) Thefibers pass through the upper and middle trunks and the posterior cord, andcontinues with the lower subscapular nerve.

Occasionally this nerve is a branch of the axillary and radial nerves

A motor branch goes to the latissimus dorsi muscle, and may also innervatethe teres major muscle

Both muscles are adductors and inward rotators of the scapulohumeral jointand help to bring down the elevated arm (see Fig 29)

Few clinical symptoms, weakness compensated in part by pectoralis major andteres major muscles

Signs:

Atrophy, and slight winging of the inferior margin of the scapulaMotor: Latissimus dorsi: weakness in adduction and medial rotation of shoulderand arm

Isolated lesion is very uncommon

Neuralgic amyotrophy (rarely)Plexus lesions: injury in association with posterior cord or more proximalbrachial plexus lesions

Patients note painless atrophy.

Weakness and atrophy of the pectoral muscle Compensatory hypertrophy of

other chest muscles

Lateral pectoral nerve:

Receives fibers from C5–7 (lateral cord of plexus) and supplies upper part of

pectoral muscle

Medial pectoral nerve:

Receives fibers from C8/T1 and supplies lower part of pectoral muscle

Thoracic spinal nerves

Three groups: T1, T2–T6, T7–T12

a) T1 and C8: first intercostal nerveb) T2–T6: innervation of the chest wallT2 is the intercostobrachial nerve (see also brachial plexus)c) T7–11: Thoracoabdominal nerves

T12 is the subcostal nerve

Pain, sensory symptoms, depending on whether dorsal or ventral rami areaffected

Muscle weakness may be difficult to assess, except in the case of abdominalmuscles, where bulging occurs during coughing or pressure elevation

Compressive:

Abdominal cutaneous nerve entrapmentNotalgia paresthetica: involvement of dorsal radicular branchesThoracic disc disease (rare)

Postoperative (abdominal surgery, post mastectomy, and thoracotomy)

Laboratory: Fasting glucose, serology (herpes, borreliosis)

CSF examination (e.g., pleocytosis and antibodies in Lyme disease)

Imaging: vertebral column: plain X-ray, CT, MRI

Electrophysiology: NCV of intercostal nerves is difficult and not routinely done

EMG: paraspinal muscles, intercostals, abdominal wall muscles

Local painful conditions of the vertebral column (disc herniation,

spondylodis-citis, metastasis)

“Intercostal neuralgia”

Muscle disease with abdominal weakness

Slipping rib/Cyriax syndrome

Depends on the etiology

Daffner KR, Saver JL, Biber MP (2001) Lyme polyradiculoneuropathy presenting as

increas-ing abdominal girth Neurology 40: 373–375

Gilbert RW, Kim JH, Posner JB (1978) Epidural spinal cord compression from metastatic

tumor; diagnosis and treatment Ann Neurol 3: 40–51

Love JJ, Schorn VG (1965) Thoracic disc protrusions JAMA 191: 627–631

Stewart JD (1999) Thoracic spinal nerves In: Stewart JD (ed) Focal peripheral neuropathies.

Lippincott, Philadelphia, pp 499–508

Vial C, Petiot P, Latombe D, et al (1993) Paralysie des muscles larges de l àbdomen due a

une maladie de Lyme Rev Neurol (Paris) 149: 810–812

Differential diagnosis

Therapy References Diagnosis

Differential diagnosis

The intercostal nerves are the ventral rami of the thoracic spinal nerves Theyinnervate the intercostal (first 6) and abdominal muscles (lower 6), as well asskin (via anterior and lateral branches) The first ventral ramus is part of thebrachial plexus

(stem-The 7–11th ventral rami are called the thoracoabdominal nerves

The 12th thoracic nerve is the subcostal nerve

Radicular pain (beltlike)

Over the thorax cavity, no muscle weakness can be detected However, bulging

of abdominal muscles may be apparent

Abdominal cutaneous nerve entrapmentDiabetic truncal neuropathy

Herpes zosterNotalgia parestheticaPost-operatively: abdominal, retroperitoneal, and renal surgery

Traumatic lesionsThoracic disc trauma (rarely)Vertebral metastasis

Laboratory: fasting glucoseSerology (herpes, Lyme disease)Imaging: vertebral column, MRIElectrophysiology is difficult in trunk nerves and muscles

Pain may be of intra-thoracic, intra-abdominal, or spinal origin

Compartment syndrome of the rectus abdominis muscle

Krishnamurthy KB, Liu GT, Logigian EL (1993) Acute Lyme neuropathy presenting with

polyradicular pain, abdominal protrusion, and cranial neuropathy Muscle Nerve 16:

1261–1264

Mumenthaler M, Schliack H, Stöhr M (1998) Läsionen der Rumpfnerven In: Mumenthaler

M, Schliack H, Stöhr M (eds) Läsionen peripherer Nerven und radikuläre Syndrome.

Thieme, Stuttgart, pp 368–374

Staal A, van Gijn J, Spaans F (1999) The intercostal nerves In: Staal A, van Gijn J, Spaans

F (eds) Mononeuropathies Saunders, Londons, pp 84–86

Stewart J (2000) Thoracic spinal nerves In: Stewart J (ed) Focal peripheral neuropathies.

Lippincott, Williams & Wilkins, Philadelphia, pp 499–508

Thomas JE (1972) Segmental zoster paresis: a disease profile Neurology 22: 459–466

Therapy References

Signs

Differential diagnosis

Anatomy Originates from lateral cutaneous nerve of second and third intercostal nerves

to innervate the posterior part of the axilla This nerve often anastomizes withthe medial cutaneous nerve of the upper arm (from the medial cord of thebrachial plexus)

Pain in the axilla, chest wall, or thorax Often occurs one or two months aftermastectomy Reduced movement of the shoulder enhances pain

Sensation is impaired in the axilla, chest wall, and proximal upper arm

Operations in the axilla (removal of lymph nodes)Following surgery for thoracic outlet syndromeLung tumors

Assa J (1974) The intercostobrachial nerve in radical mastectomy J Surg Oncol 6: 123–126

Intercostobrachial nerve

Reference

Iliohypogastric nerve

Fig 30 lliohypogastric nerve

anatomy 1 lliohypogastric nerve 2 llioinguinal nerve 3 Obturator nerve 4 Genitofemo- ral nerve

Fibers originate at L1, then emerge from the lateral border of the psoas, crossing

the lower border of the kidney, then the lateral abdominal wall Then the nerve

crosses the transverse abdominal muscle above iliac crest and passes between

the transverse and oblique internal abdominal muscles Finally two branches

are given off: the lateral anterior and anterior cutaneous nerves

Burning and stabbing pain in the ilioinguinal region, which may radiate

to-wards the genital area or hip Symptoms increase when walking

Difficult to examine Spontaneous bulging of abdominal wall Sensory deficit

may be present Tinel’s sign over a surgical scar may be observed Slight flexion

of hip while standing

Symptoms

Signs Anatomy

Electrophysiology is not routinely available Clinical distribution.

Spontaneous entrapment in abdominal wall, surgery, hernioraphy,

appendecto-my, abdominoplasty, nephrectoappendecto-my, endometriosis

Steroids locally, scar removal, neurolysis

Diagnosis

Therapy

Differential diagnosis

Ilioinguinal nerve

Fig 31 llioinguinal nerve omy a A-female 1 llioinguinal nerve b B-male 1 lliohypogas-

anat-tric nerve 2 llioinguinal nerve

Fig 32 Ilioinguinal nerve

le-sion after gynecologic surgery The sensory loss (marked with a ball pen) reached almost the la- bia

The ilioinguinal nerve originates with fibers from T12 and L1 The motorcomponent innervates the internal and external oblique muscles, and thetransverse abdominal muscle.

The sensory component covers the skin overlying the pubic symphysis, thesuperomedial aspect of the femoral triangle, the anterior scrotal surface, and theroot of the penis/labia majora and mons pubis (Fig 31)

Hyperesthesia, sometimes with significant pain over the lower abdominalquadrant and the inguinal region and genitalia (Fig 32)

Weakness of lower abdominal muscles, hernia.

Abdominal operations with a laterally placed incisionBiopsy

Endometriosis, leiomyoma, lipomaHerniotomy

Iliac bone harvestingPregnancy, child birthSpontaneous entrapment – “inguinal neuralgia“

Studies: no standard electrophysiologic techniques are available

Local anesthetic infiltrationSurgical exploration and resection of the nerve

Genitofemoral neuropathyInguinal pain syndromeIliohypogastric neuropathyL1 radiculopathy (very rare)

Dawson DM (1990) Miscellaneous uncommon syndromes In: Dawson DM (ed) ment neuropathies Little Brown, Boston, pp 307–323

Entrap-Komar J (1971) Das Ilioinguinalis Syndrom Nervenarzt 42: 637–640 Mumenthaler M (1998) Läsionen einzelner Nerven im Beckenbereich und an den unteren Extremitäten, 7 Aufl G Thieme Verlag, Stuttgart, pp 393–464

Purves JK, Miller JD (1986) Inguinal neuralgia; a review of 50 patients Can J Surg 29: 585–587

Stulz P, Pfeiffer KM (1982) Peripheral nerve injuries resulting from common surgical procedures in the lower portion of the abdomen Arch Surg 117: 324–327

Genitofemoral nerve

Symptoms

Signs Causes

Diagnosis

Differential diagnosis

Therapy

Prognosis References

Anatomy

The nerve originates from the ventral primary rami of L1 and L2, then runs

along the psoas muscle to the inguinal ligament In the inguinal canal the

genital branch runs with the ilioinguinal nerve, to supply the skin of the mons

pubis and labium majus The genital branch also innervates the cremaster

muscle, while the femoral branch innervates the proximal anterior thigh

May give rise to continuous pain, sometimes called “spermatic neuralgia”

Can present as a post-operative inguinal neuralgia

Paresthesias (may be painful) of the medial inguinal region, upper thigh, side of

scrotum, and labia majora

Tenderness in the inguinal canal Cremaster reflex unreliable

No electrophysiologic studies are available

Diagnostic anesthetic blockade

Staal A, van Gijn J, Spaans F (1999) The genitofemoral nerve In: Staal A, van Gijn J, Spaans

F (eds) Mononeuropathies Saunders, London, pp 95–96

Superior and inferior gluteal nerves

Genetic testing NCV/EMG Laboratory Imaging Biopsy

Fig 33 Superior gluteal nerve

anatomy 1 Superior gluteal

nerve

Fig 34 Trendelenburg’s sign,

indicating weakness of the hip

abductors (gluteus medius

mus-cle) A Standing on both feet the

pelvis remains in horizontal

po-sition B When the patient

stands on his left leg, his pelvis

tilts to the right side This patient

had a left gluteus medius nerve

lesion, caused by an iliac

aneu-rysm Note that the greater

glu-teal muscles are not affected

Superior gluteal nerve:

Originates with the posterior branches from ventral rami of L4–S1, to innervate

the gluteus medius and minimus muscles

Inferior gluteal nerve:

Originates with the posterior portions of L5 and S1, and ventral primary rami of

S2 It innervates the piriformis and gluteus maximus muscles

Superior:

Causes Trendelenburg’s gait Excessive drop of the non-weight-bearing limb

and a steppage gait on the unaffected side Hip abduction is weak, sensation is

Rarely isolated, often associated with the sciatic nerve, occasionally with

pudendal nerve Colorectal carcinoma, injections, trauma

EMG, imaging

Sacral plexus lesion

Hip and pelvic pathology

Grisold W, Karnel F, Kumpan W, et al (1999) Iliac artery aneurysm causing isolated

superior gluteal nerve lesion Muscle Nerve 22: 1717–1720

Rask MR (1980) Superior gluteal nerve entrapment syndrome Muscle Nerve 3: 304–307

Wilbourn AJ, Lesser M (1983) Gluteal compartment syndrome producing sciatic and

gluteal mononeuropathies: a report of two cases Electrencephal Clin Neurophysiol 55:

45–46

Symptoms and Signs

Pathogenesis

Diagnosis Differential diagnosis

References Anatomy

Pudendal nerve

Genetic testing NCV/EMG Laboratory Imaging Biopsy

Fig 35 Pudendal nerve

anato-my a 1 Pudendal nerve 2

Perineal nerves 3 Dorsal nerve

of clitoris 4 Inferior rectal

nerves b 1 Perineal nerves 2

Pudendal nerves

Fig 36 Pudendal nerve

anato-my a1 Dorsal nerve of penis 2 Pudendal nerve 3 Perineal

nerves b 1 Perineal branch of cutaneous femoral posterior nerve 2 Pudendal nerve 3 Rec- tal inferior nerves 4 Bulbo spongiosus muscle 5 External anal sphincter muscle

Clinical picture

Signs

Causes

Anatomy The nerve originates from S2–S4, and passes through the sciatic foramen and

pudendal canal Its terminal branches are the inferior rectal nerve (innervatingthe levator ani, external anal sphincter muscles, and skin around the anus), theperineal nerve (innervating the external urethral sphincter muscles, bulbocaver-nosus, perineum, and dorsal aspect of scrotum/labia), and the terminal branch

of the pudendal nerve (providing sensation to the clitoris, glans penis, dorsalregion of the penis) (see Fig 35 through 37)

Perineal sensory symptoms, sexual dysfunction

Bilateral lesions may cause urinary or fecal incontinence, gasmy, and sensory disturbances

impotence/anor-Sphincter reflexes (anal, bulbocavernosus reflex absent)

Selective injury is rareExternal compression:

Perineal, post-operative of hip fracturesLong bicycle rides

Suturing through sacrospinal ligament during colonoscopyStretch:

Straining during defecationChildbirth

Pelvic fracturePelvic surgery

Fig 37 Pudendal nerve

anato-my 1 Cutaneous femoris

poste-rior nerve 2 Labial/scrotal

nerves 3 Anococcygeal nerve

Structural abnormalities of the pelvic floor or viscera

EMG of external anal sphincter

Bulbocavernosus reflex

Pudendal SEP

Anorectal manometry, urodynamic examinations

Imaging

Amarenco G, Ismael SS, Bayle B, et al (2001) Electrophysiological analysis of pudendal

neuropathy following traction Muscle Nerve 24: 116–119

Podnar S, Vodusek DB (2001) Standardization of anal sphincter electromyography: utilty of

motor unit potential parameters Muscle Nerve 24: 946–951

References Differential diagnosis

Diagnosis

Mononeuropathies: lower extremities

Obturator nerve

Fig 38 Obturator nerve

anato-my 1 Obturator nerve 2 neous femoris posterior nerve.

Cuta-3 Sapheneous nerve 4 neal nerve 5 Sural nerve 6 Lat- eral plantar nerve 7 Medial plantar nerve

Calca-The obturator nerve fibers stem from L2–4, and course within the belly of the

psoas muscle, emerging on the medial side of the psoas, then passing over the

sacroiliac joint, and continuing along the wall of pelvis to the obturator canal

Sensory loss, paresthesias, or radiating pain in the medial thigh Disability in

walking due to impaired stabilization of the hip joint The leg is held in an

Symptoms Anatomy

abducted position, leading to a wide-based gait The adductor tendon reflexmay be absent.

Neuralgic pain may be confused with osteitis

Adductor weakness, with or without sensory deficits

Compression: Obturator hernia, scar in thigh, labor, endometriosis, neal Schwannoma

retroperito-Iatrogenic: Hip surgery, fixation of acetabular fracture, intrapelvic surgeryLaparoscopic dissection of pelvic nodes, gracilis flap, prostatectomy

Hypogastric artery aneursymMetastatic cancer

Trauma: pelvic fracture, gunshot, retroperitoneal hematomaObturator nerve injury occurs commonly with a femoral nerve lesion Causesinclude retroperitoneal hematoma, cancer, hip arthroplasty, lymphoma

EMGImaging

L2–L4 radiculopathy

Depends on etiology and type of nerve injury

Depends on etiology and type of nerve injury

Roger LR, Borkowski GP, Albers JW, et al (1993) Obturator mononeuropathy caused by pelvic cancer: six cases Neurology 43: 1489–1492

Sorenson EJ, Chen JJ, Daube JR (2002) Obturator neuropathy: causes and outcome Muscle Nerve 25: 605–607

Staal A, van Gijn J, Spaans F (1999) The obturator nerve In: Staal A, van Gijn J, Spaans F (eds) Mononeuropathies; examination, diagnosis and treatment Saunders, London,

Femoral nerve

Genetic testing NCV/EMG Laboratory Imaging Biopsy

Fig 39 Femoral nerve

anato-my 1 Femoral nerve 2 ous nerve 3 Patellar branch