NOTES AND NEW DEVELOPMENTS
LUMBAR PLEXUS NEUROPATHY RESULTING FROM RETROPERITONEAL HEMORRHAGE Scott Emery, MD, and Jose Ochoa, MD, PhD
Abstract: A case of lumbar plexus neuropathy occurring
in the setting of heparin therapy is reported. Documentation of the site of a retroperitoneal hematoma by CT scan was made prior to the full clinical evolution of a lumbar plexus neuropathy resulting from a psoas-muscle hematoma. Two patterns of retroperitoneal bleeding and their respective clinical manifestations are discussed. Early diagnosis of these syndromes may allow for intervention before neurologic compromise is established. MUSCLE & NERVE 1:330-334 1978
Retroperitoneal hemorrhage resulting from hemophilia and from a n t i c o a g u l a n t t h e r a p y is a p h e nomenon t h a t has been recognized for a n u m b e r of years. A c u t e l u m b a r plexus or femoral n e u r o p a t h y may sometimes be t h e major clinical manifestation of this event. I t is important to recognize s u c h neuropathy because significant m o r b i d i t y is associated w i t h t h e nerve lesion, and because it may i n d i c a t e t h e presence of a retroperitoneal hemorrhage. In the present case, diagnosis of t h e site of h e m o r r h a g e was confirmed by CT scan. The clinical syndromes and diagnosis o f the neuropathies associated w i t h retroperitoneal hemorrhage are discussed.
episode ofventilatory failure, she recovered satisfactorily over the course of a month and returned home. She reentered the hospital several weeks later because of recurrent fever and was found to have Staphylococcur epidermrdu endocarditis, for which antibiotic therapy was given. O n December 14, 1977, she complained of several episodes of transient dysphasia and had mild right-sided hyperreflexia and increased tone without weakness. There was no evidence of dysphasia at the time of examination. A CT scan of the brain showed no abnormality. O n December 22, 1977, the patient developed symptoms and signs of left-calf thrombophlebitis. A lung scan and venogram confirmed the thrombophlebitis and indicated pulmonary embolization. Clotting parameters were all within normal limits. A bolus of 5,000 units of heparin was given intravenously, followed by a continuous infusion of 1,000 units per hour. The patient improved the next day, but on the morning of December 24, about 32 hr after initiation of heparin therapy, she noticed aching of the left groin while getting off the bedpan. This aching rapidly became an excruciating pain that radiated from her left groin down the anterior aspect of the thigh to the knee. She was aware of no weakness, numbness, or paresthesia. Coagulation studies revealed a protime of 14 sec (control of 12), a PTT of 74 sec (control of 37), and a normal platelet count. Examination showed absence of a left knee jerk and no sensory loss to pinprick or to light touch. Strength was difficult to assess because of the pain, but left knee extension seemed disproportionately weak. No Tinel’s sign, swelling, or ecchymosis was noted, and the hip was not held in flexion. A clinical diagnosis of retroperitoneal hemorrhage was made. A CT scan of the lumbar and pelvic region showed effacement of the tissue planes along the course of the left psoas muscle and enlargement of the psoas muscle itself, with density measurements consistent with those of hemorrhage. T h e psoas muscle on
CASE REPORT
A 58-year-old woman with a history of rheumatic fever had an automobile accident on October 10, 1977, in which she suffered superficial head injuries as well as rib and pelvic fractures. A lapamtomy yielded no evidence of abdominal pathology. Although she had multiple complications during hospitalization, including congestive heart failure a n d a n
330
Lumbar Plexus Neuropathy
From the Neurology Section, Dartmouth Medical School, Hanover, NH. Address reprint requeststo Dr. Ochoa at the Neurology Section, Dartmouth Medical School, Hanover. NH 03755. Received for publication May 21, 1978. o,48~639x,o,04,0330 ~oo,oo,o o 1978 Houghton Mifflin Professional Publishers
MUSCLE & NERVE
Jul/Aug 1978
the right appeared normal (fig. 1). Heparin was discontinued, and a n inferior vena caw “umbrella” was utilized to prevent further pulmonary embolization. Over the next 24 hr, the patient developed numbness to pinprick over the femoral a n d lateral femoral cutaneous-nerve distribution, as well as a marked increase in muscle weakness, with absent left knee extension and moderate impairment of hip flexion, adduction, abduction, and knee flexion on the left. Strength in the flexors and dorsiflexors of the left ankle was intact. T h e left knee jerk remained absent. Pain diminished markedly over the next day. Her hemoglobin dropped about 1 g/100 nil. O n December 28, four days after the onset of symptoms, she had complete paralysis of knee extension and weakness of hip flexion and adduction against resistance. Sensory examination is shown in figure 2. Electrophysiologic studies on the same day revealed no voluntary or reflex motor-unit activity in the left vastus mrdialis, and an inexcitable femoral nerve a t the groin. The patient was discharged from the hospital three weeks later with no change in her neurologic status. She was able to walk with the assistance of a brace and cane. One month later, her functional status remained unchanged. T h r sensory abnormality had diminished to an area of hypesthesia over t h r saphenous-nerve distribution, with an area of hyperalgesia to pinprick over the anterior femoral cutaneous-nerve distribution. T h e left knee jerk remained absent, and there was complete paralysis of knee extension, with wasting of the quadriceps and markedly diminished strength in the hip adductors and flexors. EMG examination showed profuse spontaneous fibrillation, positive sharp waves, and no motor-unit activity in the quadriceps and adductor magnus muscles.
DISCUSSION
Retroperitoneal hemorrhage is a recognized complication of both hemophilia’ and anticoagulant therapy. Diagnosis may be difficult. A constellation of neu-
rologic signs and symptoms may serve as a guide to diagnosis, and these may in turn become the cause of significant and prolonged morbidity. In a study of 37 retroperitoneal hematomas by Morrison and Wurzel,’” one-third of such hematomas occurred in patients receiving heparin therapy. In a prospective study by Mant et al of 76 patients with venous thromboembolic disease treated with heparin, five (6.6%)developed major retroperitoneal bleeding.’ With the diagnostic capability of computed tomography and ultrasonography, the incidence and natural history of this entity will undoubtedly become more clearly defined. Hematoma formation in hemophilic and anticoagulated patients may be due to minor trauma of the hip flexor muscles, with dissection along fascial planes and filling of retroperitoneal potential spaces. Dissection of blood into the retroperitoneal spaces from the deep fascial planes of the thigh, glutei, flank, and abdominal wall following intramuscular injections has been d e ~ c r i b e d . ~ ~ ’ J ~ ’ A brief review of the anatomy of the femoral nerve and the lumbar plexus may help delineate two syndromes of neurologic involvement with bleeding into the retroperitoneal musculature and fascial planes. The lumbar plexus is formed within the psoas major muscle from the anterior primary divisions of the twelfth thoracic through the fourth lumbar (L4) spinal roots. Within the muscle, the anterior branches of the L2, L3, and L4 roots join, leave the psoas muscle medially, and descend as the obturator nerve, innervating the adductor muscles of the thigh and having a somewhat variable sensory distribution on the distal medial aspect of the thigh. The femoral nerve is formed from the posterior branches of the same spinal roots within the psoas but exits laterally, descending in the
Figure 7. CT scan at the level of L3, showing marked increase in the volume of the left-psoas profile as compared with the normal on the right.
Lumbar Plexus Neuropathy
MUSCLE & NERVE
Jul/Aug 1978
331
Figure 2. Paralysis of left knee extension and sensory loss to pinprick extending beyond femoral-nerve distribution on the fourth day.
intermuscular groove between the psoas medially and the iliacus laterally. It is covered by iliacus fascia as it courses between the muscles and underneath the inguinal ligament. This segment of the nerve appears to have a relatively sparse blood supply in comparison to the intrapsoas and distal portions of the nerve.Is Beneath the inguinal ligament, the nerve enters the lateral portion of the femoral triangle and divides into its terminal branches. The femoral nerve supplies motor innervation to the quadriceps group and, less commonly, to the iliacus and psoas muscles. Cutaneous sensory distribution extends from the anterior distal two-thirds of the thigh and from the knee (anterior femoral cutaneous nerve) and the medial aspect of the lower leg to the medial malleolus (saphenous nerve). The lateral femoral cutaneous nerve is formed from branches of the L2 and L3 roots within the psoas, leaving the muscle laterally to cross the iliacus muscle and enter the thigh deep to the inguinal ligament. It relays sensation from the lateral aspect of the thigh. The psoas major muscle has its origins in the transverse processes, bodies, and intervertebral discs of the lumbar and lowest thoracic vertebrae. The muscle runs beneath the inguinal ligament, joining the iliacus to insert on the lesser trochanter of the femur as the ihopsoas. The iliacus originates on the ventral aspect of the iliac crest lateral to the psoas muscle, and it then descends to insert together with the psoas. Both muscles derive direct innervation from proximal segments of the L2 through L4 roots. Two anatomically distinct syndromes involving pain as well as sensory and motor disturbances in the
332
Lumbar Plexus Neuropathy
lower extremities appear to be associated with hemo.~~~ of the lumbar philia or a n t i c o a g ~ l a t i o nInvolvement plexus is produced by hematoma within the psoas muscle. This is clinically manifested by weakness of the thigh adductors as well as the hip flexors and knee extensors; by loss of knee jerk; and by variable sensory loss in the leg, which may include the lateral femoral cutaneous-nerve distribution. Generally, the hemorrhage associated with this entity seems to be larger, perhaps because of the larger and more distensible psoas sheath. It is also distinctly less common than involvement of the femoral nerve alone. In Chiu’s review of the literature of lumbar plexus and femoralnerve lesions associated with anticoagulation, 7 (50%) of 14 patients with apparent plexus lesions required blood transfusion, in comparison to 3 (25%) of 12 in those with a pure femoral-nerve palsy-suggesting that the former patients sustain a larger blood loss than do the latter before neurologic involvement becomes apparent.5 Intrapsoas hemorrhage can be detected by CT scan, as in the case presented, where enlargement of the left psoas outline by blood density material was seen at the L2 through L4 vertebral levels. To our knowledge, this is the first reported case in which a psoas hematoma producing a plexus neuropathy has been documented by CT scan. The second syndrome consists of pure femoralnerve palsy with sensory loss over the anterior femoral cutaneous-nerve and saphenous-nerve distributions; loss of knee jerk; and loss of quadriceps and (to a lesser extent) hip-flexor functions. This may be produced by hematoma within the iliacus muscle above the ingui-
MUSCLE & NERVE
Jul/Aug 1978
nal ligament or within the iliopsoas below. 'The quantity of hemorrhage sufficient to produce this syndrome appears to be less than that responsible for the first syndrome. A tight fascia1 covering in the intermuscular groove, producing a higher pressure with a lowervolume hematoma, predisposes to a compression neuropathy in the region of t h e inguinal ligament. Further compromise may occur from the relative paucity o f blood supply to this segment of the nerve.I5 O n clinical examination, a discrete swelling in the groin and antalgic flexion of the hip with pain on extension are described in cases of both suprainguinal and infrainguinal involvement of the nerve.7 Demonstration of this entity by C T scan has recently been reported.'" Twenty-six patients with femoral-nerve or lumbar plexus neuropathies were reviewed by chi^.^ A common clinical composite was distilled from this group, all of whom had been treated with anticoagulants. In about half of the cases, anticoagulant therapy had been instituted for thrombophlebitis or pulmonary cmbolization; in this sample, both heparin and warfarin were implicated. The onset of severe pain typically occurred approximately one week after initiation of therapy, and after some activity had resumed. The pain was intense, occurring in the lower abdomen and groin and radiating to the thigh and leg. This was followed by paresthesias and pain that increased on movement and led to the adoption of hip flexion and external rotation. Motor deficits followed and were usually complete within 24 hr. Ecchymosis and a palpable mass in the groin or iliac fossa were seen in some patients. Signs of hypovolemia were common. Pain usually diminished within one week. Therapeutic ranges of coagulation parameters at the time of hemorrhage on heparin therapy are common.",g Our patient followed a similar clinical course, with a few points of difference. The interval between heparinization and the onset of symptoms was about 32 hr. Bleeding within the first two days of heparin therapy is relatively uncommon.' Motor signs at the onset were not prominent and were difficult to assess because of pain, with the exception of the absent tendon reflex at the knee. Sensory disturbance occurred during the second day, after the diagnosis had been made. No hip flexion. mass, or ecchymosis occurred. No signs of hypovolernia were present, a n d the hemoglobin dropped only about 1 g/lOQ ml. In a report of seven cases, Sagel and coauthors illustrated the use of C T scanning in diagnosing retroperitoneal hemorrhage.'? In none of their patients was neurologic deficit reported. The use of CT scanning in our patient is of particular interest in that the diagnosis was confirmed before the clinical evolution was complete.
Lumbar Plexus Neuropathy
Although purely intraneural bleeding has been described pathologically in at least one case of femoral neuropathy in the setting of hemophilia without hematoma formation, it is generally believed that compression by hematoma is the underlying factor in the etiology of the neuropathies associated with coagi~lopathies.~~~ Several authors have suggested that immediate surgical decompression may improve the prognosis of the femoral neuropathy in anticoagulant-treated pat i e n t ~ . ? ,Conservative ~~ therapy is usually recommended in hemophilia. No experience has been reported in the management of neuropathy produced by psoas hematoma. In either clinical syndrome, it seems possible that the CT scan may show sufficient localization of the hematoma early in the clinical course to allow surgical decompression to be undertaken before a more severe compression neuropathyand subsequent axonal degeneration-becomes inevitable. Although no standardized method has been used to evaluate recovery, complete return of function has been noted in only one-third or less of all cases treated con~ervatively.~~'~ The possibility of a relationship between lumbar puncture (which the patient underwent 4 hr before heparin therapy) and the development of retroperitoneal hemorrhage is speculative. The location and the temporal association suggest a relationship, but this must be a very rare complication or a coincidental occurrence. In this case study, a relationship of the hemorrhage to the patient's prior trauma or to her endocarditis is also possible. Other conditions that have been reported in association with femoral-nerve or lumbar plexus neuropathy are diabetic mononeuropathy, herpes zoster, malignant involvement of the iliac nodes, psoas abscess, aneurysm or false aneurysm of the aorta or iliac vessels, vasculitis, and even inflammatory disease of the hip joint.".*," A coincidence of one of these etiologies with hemorrhage resulting from anticoagulation seems unlikely. In summary, this article reported a case of lumbar plexus neuropathy in the setting of heparin therapy. Documentation of the Reports of this lesion are site of hematoma was made by CT scan on the first day of symptoms, before full clinical evolution of the syndrome. Delay in diagnosing a patient's symptoms can be considerably reduced with use of CT body scanning. It is possible that early decompression of the hematoma may reduce the morbidity associated with the neurologic deficit. Prompt reversal of coagulation defects may also reduce the acute retroperitoneal blood loss. Two clinically and anatomically distinct but related syndromes were discussed: the psoas and iliacus hematoma syndromes.
MUSCLE & NERVE
Jul/Aug 1978
333
REFERENCES 1. Aggeler PM, Lucia SP: The neurological complications of hemophilia. J Nerv Ment Dis 99:475-500, 1944. 2. Bigelow NH, Graves RW: Peripheral nerve lesions in hemorrhagic disease. Arch Neurol Psychiatry 68:819-830, 1952. 3. Brantigan JW, Owens ML, Moody FG: Femoral neuropathy complicating anticoagulant therapy. A m J Surg 132:108-109, 1976. 4. Calverly JR, Mulder DW: Femoral neuropathy. Neurolo~ty(Minneap) 10:963-967, 1960. 5. Chiu WS: The syndrome of retroperitoneal hemorrhage and lumbar plexus neuropathy during anticoagulant therapy. South Mcd Jour 69:595-599, 1976. 6. DeBolt WL, Jordan JC: Femoral neuropathy from heparin hematoma. Bull Los Angeles Neurol SOC31:45-50, 1966. 7. GoodfellowJ, Fearn CBd'A, Matthews JM: Iliacus hematoma. J BoneJoznt Surg [Br] 49:748-756, 1967. 8. Kubacz GJ: Femoral and sciatic compression neuropathy. Br J Surg 58:580-582, 1971.
334
Lumbar Plexus Neuropathy
9. Mant MJ, O'Brien BD, Thong KL, Hammond GW, Birtwhistle RV, Grace MG: Hemorrhagic complications of heparin therapy. Lancet 1:(8022) 1133-1135, 28 May 1977. 10. Morrison FS, Wurzel HA: Retroperitoneal hemorrhage during heparin therapy. Am J Curdiol 13:329-332, 1964. 11. Radashekhar TP, Herbison GJ: Lumbosacral plexopathy caused by retroperitoneal hemorrhage: report of two cases. Arch Phys Med Rehabil55:91-93, 1974. 12. Razzuk MA, Linton RR, Darling RC: Femoral neuropathy secondary to ruptured abdominal aortic aneurysm with false aneurysms. JAMA 201:817-820, 1967. 13. Sagel SS: Detection of retroperitoneal hemorrhage by CT. A m J Romtgenol 129:403-407, 1977. 14: Simeone JF, Robinson F, Rothman SLG, Jaffe CC: Computerized tomographic demonstration of a retroperitoneal hematoma causing femoral neuropathy.] Neurosurg 47:946-948, 1977. 15. Young MR, Norris JW: Femoral neuropathy during anticoagulant therapy. Neurolou (Minneap) 26: 1173-1 175, 1976.
MUSCLE 8. NERVE
Jul/Aug 1978
LUMBAR PLEXUS NEUROPATHY RESULTING FROM RETROPERITONEAL HEMORRHAGE Scott Emery, MD, and Jose Ochoa, MD, PhD
Abstract: A case of lumbar plexus neuropathy occurring
in the setting of heparin therapy is reported. Documentation of the site of a retroperitoneal hematoma by CT scan was made prior to the full clinical evolution of a lumbar plexus neuropathy resulting from a psoas-muscle hematoma. Two patterns of retroperitoneal bleeding and their respective clinical manifestations are discussed. Early diagnosis of these syndromes may allow for intervention before neurologic compromise is established. MUSCLE & NERVE 1:330-334 1978
Retroperitoneal hemorrhage resulting from hemophilia and from a n t i c o a g u l a n t t h e r a p y is a p h e nomenon t h a t has been recognized for a n u m b e r of years. A c u t e l u m b a r plexus or femoral n e u r o p a t h y may sometimes be t h e major clinical manifestation of this event. I t is important to recognize s u c h neuropathy because significant m o r b i d i t y is associated w i t h t h e nerve lesion, and because it may i n d i c a t e t h e presence of a retroperitoneal hemorrhage. In the present case, diagnosis of t h e site of h e m o r r h a g e was confirmed by CT scan. The clinical syndromes and diagnosis o f the neuropathies associated w i t h retroperitoneal hemorrhage are discussed.
episode ofventilatory failure, she recovered satisfactorily over the course of a month and returned home. She reentered the hospital several weeks later because of recurrent fever and was found to have Staphylococcur epidermrdu endocarditis, for which antibiotic therapy was given. O n December 14, 1977, she complained of several episodes of transient dysphasia and had mild right-sided hyperreflexia and increased tone without weakness. There was no evidence of dysphasia at the time of examination. A CT scan of the brain showed no abnormality. O n December 22, 1977, the patient developed symptoms and signs of left-calf thrombophlebitis. A lung scan and venogram confirmed the thrombophlebitis and indicated pulmonary embolization. Clotting parameters were all within normal limits. A bolus of 5,000 units of heparin was given intravenously, followed by a continuous infusion of 1,000 units per hour. The patient improved the next day, but on the morning of December 24, about 32 hr after initiation of heparin therapy, she noticed aching of the left groin while getting off the bedpan. This aching rapidly became an excruciating pain that radiated from her left groin down the anterior aspect of the thigh to the knee. She was aware of no weakness, numbness, or paresthesia. Coagulation studies revealed a protime of 14 sec (control of 12), a PTT of 74 sec (control of 37), and a normal platelet count. Examination showed absence of a left knee jerk and no sensory loss to pinprick or to light touch. Strength was difficult to assess because of the pain, but left knee extension seemed disproportionately weak. No Tinel’s sign, swelling, or ecchymosis was noted, and the hip was not held in flexion. A clinical diagnosis of retroperitoneal hemorrhage was made. A CT scan of the lumbar and pelvic region showed effacement of the tissue planes along the course of the left psoas muscle and enlargement of the psoas muscle itself, with density measurements consistent with those of hemorrhage. T h e psoas muscle on
CASE REPORT
A 58-year-old woman with a history of rheumatic fever had an automobile accident on October 10, 1977, in which she suffered superficial head injuries as well as rib and pelvic fractures. A lapamtomy yielded no evidence of abdominal pathology. Although she had multiple complications during hospitalization, including congestive heart failure a n d a n
330
Lumbar Plexus Neuropathy
From the Neurology Section, Dartmouth Medical School, Hanover, NH. Address reprint requeststo Dr. Ochoa at the Neurology Section, Dartmouth Medical School, Hanover. NH 03755. Received for publication May 21, 1978. o,48~639x,o,04,0330 ~oo,oo,o o 1978 Houghton Mifflin Professional Publishers
MUSCLE & NERVE
Jul/Aug 1978
the right appeared normal (fig. 1). Heparin was discontinued, and a n inferior vena caw “umbrella” was utilized to prevent further pulmonary embolization. Over the next 24 hr, the patient developed numbness to pinprick over the femoral a n d lateral femoral cutaneous-nerve distribution, as well as a marked increase in muscle weakness, with absent left knee extension and moderate impairment of hip flexion, adduction, abduction, and knee flexion on the left. Strength in the flexors and dorsiflexors of the left ankle was intact. T h e left knee jerk remained absent. Pain diminished markedly over the next day. Her hemoglobin dropped about 1 g/100 nil. O n December 28, four days after the onset of symptoms, she had complete paralysis of knee extension and weakness of hip flexion and adduction against resistance. Sensory examination is shown in figure 2. Electrophysiologic studies on the same day revealed no voluntary or reflex motor-unit activity in the left vastus mrdialis, and an inexcitable femoral nerve a t the groin. The patient was discharged from the hospital three weeks later with no change in her neurologic status. She was able to walk with the assistance of a brace and cane. One month later, her functional status remained unchanged. T h r sensory abnormality had diminished to an area of hypesthesia over t h r saphenous-nerve distribution, with an area of hyperalgesia to pinprick over the anterior femoral cutaneous-nerve distribution. T h e left knee jerk remained absent, and there was complete paralysis of knee extension, with wasting of the quadriceps and markedly diminished strength in the hip adductors and flexors. EMG examination showed profuse spontaneous fibrillation, positive sharp waves, and no motor-unit activity in the quadriceps and adductor magnus muscles.
DISCUSSION
Retroperitoneal hemorrhage is a recognized complication of both hemophilia’ and anticoagulant therapy. Diagnosis may be difficult. A constellation of neu-
rologic signs and symptoms may serve as a guide to diagnosis, and these may in turn become the cause of significant and prolonged morbidity. In a study of 37 retroperitoneal hematomas by Morrison and Wurzel,’” one-third of such hematomas occurred in patients receiving heparin therapy. In a prospective study by Mant et al of 76 patients with venous thromboembolic disease treated with heparin, five (6.6%)developed major retroperitoneal bleeding.’ With the diagnostic capability of computed tomography and ultrasonography, the incidence and natural history of this entity will undoubtedly become more clearly defined. Hematoma formation in hemophilic and anticoagulated patients may be due to minor trauma of the hip flexor muscles, with dissection along fascial planes and filling of retroperitoneal potential spaces. Dissection of blood into the retroperitoneal spaces from the deep fascial planes of the thigh, glutei, flank, and abdominal wall following intramuscular injections has been d e ~ c r i b e d . ~ ~ ’ J ~ ’ A brief review of the anatomy of the femoral nerve and the lumbar plexus may help delineate two syndromes of neurologic involvement with bleeding into the retroperitoneal musculature and fascial planes. The lumbar plexus is formed within the psoas major muscle from the anterior primary divisions of the twelfth thoracic through the fourth lumbar (L4) spinal roots. Within the muscle, the anterior branches of the L2, L3, and L4 roots join, leave the psoas muscle medially, and descend as the obturator nerve, innervating the adductor muscles of the thigh and having a somewhat variable sensory distribution on the distal medial aspect of the thigh. The femoral nerve is formed from the posterior branches of the same spinal roots within the psoas but exits laterally, descending in the
Figure 7. CT scan at the level of L3, showing marked increase in the volume of the left-psoas profile as compared with the normal on the right.
Lumbar Plexus Neuropathy
MUSCLE & NERVE
Jul/Aug 1978
331
Figure 2. Paralysis of left knee extension and sensory loss to pinprick extending beyond femoral-nerve distribution on the fourth day.
intermuscular groove between the psoas medially and the iliacus laterally. It is covered by iliacus fascia as it courses between the muscles and underneath the inguinal ligament. This segment of the nerve appears to have a relatively sparse blood supply in comparison to the intrapsoas and distal portions of the nerve.Is Beneath the inguinal ligament, the nerve enters the lateral portion of the femoral triangle and divides into its terminal branches. The femoral nerve supplies motor innervation to the quadriceps group and, less commonly, to the iliacus and psoas muscles. Cutaneous sensory distribution extends from the anterior distal two-thirds of the thigh and from the knee (anterior femoral cutaneous nerve) and the medial aspect of the lower leg to the medial malleolus (saphenous nerve). The lateral femoral cutaneous nerve is formed from branches of the L2 and L3 roots within the psoas, leaving the muscle laterally to cross the iliacus muscle and enter the thigh deep to the inguinal ligament. It relays sensation from the lateral aspect of the thigh. The psoas major muscle has its origins in the transverse processes, bodies, and intervertebral discs of the lumbar and lowest thoracic vertebrae. The muscle runs beneath the inguinal ligament, joining the iliacus to insert on the lesser trochanter of the femur as the ihopsoas. The iliacus originates on the ventral aspect of the iliac crest lateral to the psoas muscle, and it then descends to insert together with the psoas. Both muscles derive direct innervation from proximal segments of the L2 through L4 roots. Two anatomically distinct syndromes involving pain as well as sensory and motor disturbances in the
332
Lumbar Plexus Neuropathy
lower extremities appear to be associated with hemo.~~~ of the lumbar philia or a n t i c o a g ~ l a t i o nInvolvement plexus is produced by hematoma within the psoas muscle. This is clinically manifested by weakness of the thigh adductors as well as the hip flexors and knee extensors; by loss of knee jerk; and by variable sensory loss in the leg, which may include the lateral femoral cutaneous-nerve distribution. Generally, the hemorrhage associated with this entity seems to be larger, perhaps because of the larger and more distensible psoas sheath. It is also distinctly less common than involvement of the femoral nerve alone. In Chiu’s review of the literature of lumbar plexus and femoralnerve lesions associated with anticoagulation, 7 (50%) of 14 patients with apparent plexus lesions required blood transfusion, in comparison to 3 (25%) of 12 in those with a pure femoral-nerve palsy-suggesting that the former patients sustain a larger blood loss than do the latter before neurologic involvement becomes apparent.5 Intrapsoas hemorrhage can be detected by CT scan, as in the case presented, where enlargement of the left psoas outline by blood density material was seen at the L2 through L4 vertebral levels. To our knowledge, this is the first reported case in which a psoas hematoma producing a plexus neuropathy has been documented by CT scan. The second syndrome consists of pure femoralnerve palsy with sensory loss over the anterior femoral cutaneous-nerve and saphenous-nerve distributions; loss of knee jerk; and loss of quadriceps and (to a lesser extent) hip-flexor functions. This may be produced by hematoma within the iliacus muscle above the ingui-
MUSCLE & NERVE
Jul/Aug 1978
nal ligament or within the iliopsoas below. 'The quantity of hemorrhage sufficient to produce this syndrome appears to be less than that responsible for the first syndrome. A tight fascia1 covering in the intermuscular groove, producing a higher pressure with a lowervolume hematoma, predisposes to a compression neuropathy in the region of t h e inguinal ligament. Further compromise may occur from the relative paucity o f blood supply to this segment of the nerve.I5 O n clinical examination, a discrete swelling in the groin and antalgic flexion of the hip with pain on extension are described in cases of both suprainguinal and infrainguinal involvement of the nerve.7 Demonstration of this entity by C T scan has recently been reported.'" Twenty-six patients with femoral-nerve or lumbar plexus neuropathies were reviewed by chi^.^ A common clinical composite was distilled from this group, all of whom had been treated with anticoagulants. In about half of the cases, anticoagulant therapy had been instituted for thrombophlebitis or pulmonary cmbolization; in this sample, both heparin and warfarin were implicated. The onset of severe pain typically occurred approximately one week after initiation of therapy, and after some activity had resumed. The pain was intense, occurring in the lower abdomen and groin and radiating to the thigh and leg. This was followed by paresthesias and pain that increased on movement and led to the adoption of hip flexion and external rotation. Motor deficits followed and were usually complete within 24 hr. Ecchymosis and a palpable mass in the groin or iliac fossa were seen in some patients. Signs of hypovolemia were common. Pain usually diminished within one week. Therapeutic ranges of coagulation parameters at the time of hemorrhage on heparin therapy are common.",g Our patient followed a similar clinical course, with a few points of difference. The interval between heparinization and the onset of symptoms was about 32 hr. Bleeding within the first two days of heparin therapy is relatively uncommon.' Motor signs at the onset were not prominent and were difficult to assess because of pain, with the exception of the absent tendon reflex at the knee. Sensory disturbance occurred during the second day, after the diagnosis had been made. No hip flexion. mass, or ecchymosis occurred. No signs of hypovolernia were present, a n d the hemoglobin dropped only about 1 g/lOQ ml. In a report of seven cases, Sagel and coauthors illustrated the use of C T scanning in diagnosing retroperitoneal hemorrhage.'? In none of their patients was neurologic deficit reported. The use of CT scanning in our patient is of particular interest in that the diagnosis was confirmed before the clinical evolution was complete.
Lumbar Plexus Neuropathy
Although purely intraneural bleeding has been described pathologically in at least one case of femoral neuropathy in the setting of hemophilia without hematoma formation, it is generally believed that compression by hematoma is the underlying factor in the etiology of the neuropathies associated with coagi~lopathies.~~~ Several authors have suggested that immediate surgical decompression may improve the prognosis of the femoral neuropathy in anticoagulant-treated pat i e n t ~ . ? ,Conservative ~~ therapy is usually recommended in hemophilia. No experience has been reported in the management of neuropathy produced by psoas hematoma. In either clinical syndrome, it seems possible that the CT scan may show sufficient localization of the hematoma early in the clinical course to allow surgical decompression to be undertaken before a more severe compression neuropathyand subsequent axonal degeneration-becomes inevitable. Although no standardized method has been used to evaluate recovery, complete return of function has been noted in only one-third or less of all cases treated con~ervatively.~~'~ The possibility of a relationship between lumbar puncture (which the patient underwent 4 hr before heparin therapy) and the development of retroperitoneal hemorrhage is speculative. The location and the temporal association suggest a relationship, but this must be a very rare complication or a coincidental occurrence. In this case study, a relationship of the hemorrhage to the patient's prior trauma or to her endocarditis is also possible. Other conditions that have been reported in association with femoral-nerve or lumbar plexus neuropathy are diabetic mononeuropathy, herpes zoster, malignant involvement of the iliac nodes, psoas abscess, aneurysm or false aneurysm of the aorta or iliac vessels, vasculitis, and even inflammatory disease of the hip joint.".*," A coincidence of one of these etiologies with hemorrhage resulting from anticoagulation seems unlikely. In summary, this article reported a case of lumbar plexus neuropathy in the setting of heparin therapy. Documentation of the Reports of this lesion are site of hematoma was made by CT scan on the first day of symptoms, before full clinical evolution of the syndrome. Delay in diagnosing a patient's symptoms can be considerably reduced with use of CT body scanning. It is possible that early decompression of the hematoma may reduce the morbidity associated with the neurologic deficit. Prompt reversal of coagulation defects may also reduce the acute retroperitoneal blood loss. Two clinically and anatomically distinct but related syndromes were discussed: the psoas and iliacus hematoma syndromes.
MUSCLE & NERVE
Jul/Aug 1978
333
REFERENCES 1. Aggeler PM, Lucia SP: The neurological complications of hemophilia. J Nerv Ment Dis 99:475-500, 1944. 2. Bigelow NH, Graves RW: Peripheral nerve lesions in hemorrhagic disease. Arch Neurol Psychiatry 68:819-830, 1952. 3. Brantigan JW, Owens ML, Moody FG: Femoral neuropathy complicating anticoagulant therapy. A m J Surg 132:108-109, 1976. 4. Calverly JR, Mulder DW: Femoral neuropathy. Neurolo~ty(Minneap) 10:963-967, 1960. 5. Chiu WS: The syndrome of retroperitoneal hemorrhage and lumbar plexus neuropathy during anticoagulant therapy. South Mcd Jour 69:595-599, 1976. 6. DeBolt WL, Jordan JC: Femoral neuropathy from heparin hematoma. Bull Los Angeles Neurol SOC31:45-50, 1966. 7. GoodfellowJ, Fearn CBd'A, Matthews JM: Iliacus hematoma. J BoneJoznt Surg [Br] 49:748-756, 1967. 8. Kubacz GJ: Femoral and sciatic compression neuropathy. Br J Surg 58:580-582, 1971.
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9. Mant MJ, O'Brien BD, Thong KL, Hammond GW, Birtwhistle RV, Grace MG: Hemorrhagic complications of heparin therapy. Lancet 1:(8022) 1133-1135, 28 May 1977. 10. Morrison FS, Wurzel HA: Retroperitoneal hemorrhage during heparin therapy. Am J Curdiol 13:329-332, 1964. 11. Radashekhar TP, Herbison GJ: Lumbosacral plexopathy caused by retroperitoneal hemorrhage: report of two cases. Arch Phys Med Rehabil55:91-93, 1974. 12. Razzuk MA, Linton RR, Darling RC: Femoral neuropathy secondary to ruptured abdominal aortic aneurysm with false aneurysms. JAMA 201:817-820, 1967. 13. Sagel SS: Detection of retroperitoneal hemorrhage by CT. A m J Romtgenol 129:403-407, 1977. 14: Simeone JF, Robinson F, Rothman SLG, Jaffe CC: Computerized tomographic demonstration of a retroperitoneal hematoma causing femoral neuropathy.] Neurosurg 47:946-948, 1977. 15. Young MR, Norris JW: Femoral neuropathy during anticoagulant therapy. Neurolou (Minneap) 26: 1173-1 175, 1976.
MUSCLE 8. NERVE
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