Nerve entrapment syndromes

Una causa rara del síndrome del nervio interóseo posterior: Lipoma intraneural

El síndrome del nervio interóseo posterior (NIP) es una condición definida por la neuropatía por compresión de esta rama del nervio radial causada por traumatismos, lesiones ocupantes de espacio, neuritis braquial, o compresión espontánea. Su presentación clínica se caracteriza por un inicio insidioso de los síntomas, generalmente un déficit en la extensión de los dedos sin alteración sensitiva. En este artículo, presentamos un caso clínico de una mujer de 72 años con un lipoma intraneural que causó compresión extrínseca por 11 meses y tuvo una recuperación completa después de la extirpación quirúrgica. Además de la escasez de casos clínicos descritos en la literatura (solo tres hasta la fecha), también destacamos la excelente evolución de la paciente, independientemente de su edad y de la duración de los síntomas.

Anterior Interosseous Nerve Syndrome

Anterior interosseous nerve syndrome (AINS) is a rare form of peripheral neuropathy which involves disruption of the anterior interosseous nerve. The pathophysiology of AINS remains unclear. AINS typically initially presents with forearm pain and may gradually progress to palsy of the deep muscles of the anterior forearm. Diagnosis of AINS requires thorough patient history and physical exam. EMG is the preferred diagnostic study and classically reveals abnormal activity and prolonged latency periods within the evoked action potentials of the FPL and PQ. Due to the self-limiting nature of AINS, there is general agreement that conservative and symptomatic management should be explored for up to 6 months as first line therapy, which usually includes analgesics and nonsteroidal anti-inflammatory drugs, contracture prevention, hand therapy, and hand splinting. Surgical options such as internal neurolysis and minimally invasive endoscopic decompression may be explored if functional recovery from conservative management is limited.

Imaging of Nerve Disorders in the Elbow

Neuropathies of the elbow represent a spectrum of disorders that involve more frequently the ulnar, radial, and median nerves. Reported multiple pathogenic factors include mechanical compression, trauma, inflammatory conditions, infections, as well as tumor-like and neoplastic processes. A thorough understanding of the anatomy of these peripheral nerves is crucial because clinical symptoms and imaging findings depend on which components of the affected nerve are involved. Correlating clinical history with the imaging manifestations of these disorders requires familiarity across all diagnostic modalities. This understanding allows for a targeted imaging work-up that can lead to a prompt and accurate diagnosis.

Operative decisions for endoscopic treatment of cubital tunnel syndrome

The authors review the relevant anatomy and provide technical tips for endoscopic decompression of the cubital tunnel. Cubital tunnel syndrome is the second most common nerve compression syndrome in the upper extremity. Until recently, surgeons focused on open decompression combined with submuscular or subcutaneous transposition of the nerve. Decompression was usually limited to the region of the medial epicondyle, and related morbidity was relatively high. Endoscopic decompression is a promising technique because the dissection range can be extended and the scar length can be reduced. The authors review the relevant anatomy for the endoscopic approach and give some recommendations concerning the details of the surgical technique.

MR imaging mapping of skeletal muscle denervation in entrapment and compressive neuropathies

The diagnoses of entrapment and compressive neuropathies have been based on the findings from clinical examinations and electrophysiologic tests, such as electromyography and nerve conduction studies. The use of magnetic resonance (MR) imaging for the diagnosis of entrapment or compressive neuropathies is increasing because MR imaging is particularly useful for discerning potential causes and for identifying associated muscle denervation. However, it is sometimes difficult to localize nerve entrapment or demonstrate nerve compression lesions with MR imaging. Nevertheless, even in these cases, MR imaging may show denervation-associated changes in specific muscles innervated by the affected nerves. The analysis of denervated muscle distributions by using MR imaging, with a knowledge of nerve innervation patterns, would be helpful for determining the nerves involved and the levels of nerve entrapment or compression. In this context, the mapping of skeletal muscle denervation with MR imaging has a supplementary or even a primary role in the diagnosis of entrapment and compressive neuropathies.

Superior cluneal nerve entrapment eight years after decubitus surgery

BACKGROUND AND OBJECTIVE

Superior cluneal nerve (SCN) entrapment is one of the infrequent etiologies of low back pain (LBP), which is rarely diagnosed. Few clinical reports have been published in the literature. We present a case of severe LBP radiating to the ipsilateral buttock after decubitus surgery.

CASE REPORT

A 62-year-old man weighing 85 kg presented to the algology department, suffering from severe LBP of 6 months duration. The pain was in the right iliac crest region with radiation to the ipsilateral buttock. After admission, his history was taken, physical examination was performed, and further evaluations were made. He was suspected of having facet and right sacroiliac joint pain. Two tender points were found 6.5 and 7.5 cm to the right of the midline over the iliac crest. Local anesthetic with corticosteroid was injected at the tender points over the right iliac crest. Five minutes after the injection, the pain dissipated.

CONCLUSION

SCN entrapment should be considered in patients who suffer from LBP radiating to the iliac crest and buttock after other causes of LBP have been excluded.

Femoral nerve entrapment: A new insight

Compression of the femoral nerve in the iliac fossa has been reported as a consequence of several pathologies, but never as a result of muscular compression. Aberrant slips of iliacus, however, have occasionally been reported to cover or split the femoral nerve. This study aimed to assess such variations as potential factors in femoral nerve compression. A large and homogeneous sample of 121 embalmed cadavers (242 specimens) was studied. Statistical comparisons were made using the chi-squared test. Muscular slips from iliacus and psoas, piercing or covering the femoral nerve, were found in 19 specimens (7.9%). No significant differences by sex or side were found. The more frequent variation was piercing of the femoral nerve by a muscular slip (17 specimens, 7.0%). The nerve then entered the thigh as one or more branches. The less frequent variation found was a muscular slip or sheet covering the femoral nerve as it lay on iliacus (2 specimens, 0.8%). Each disposition may be a potential risk for nerve entrapment.

Occupational and Sport Related Traumatic Neuropathy

BACKGROUND

Sport and occupation related traumatic nerve injury is a common problem in the United States. While the physical requirements of each pursuit place participants at risk for injury to certain peripheral nervous system structures, the vast numbers of professional and recreational pursuits limits the ability to become familiar with nerve injuries specific to each. A more pragmatic approach is to apply knowledge of mechanisms of injury, physiology of nerve injury, regional anatomy, and at-risk peripheral nervous system structures to the routine neurologic history and physical assessment to arrive at a localizing and etiologic diagnosis.

REVIEW SUMMARY

The authors discuss potential mechanisms of nerve injury, the role of electrodiagnostic testing, regional peripheral nervous system anatomic considerations and lesion localization.

CONCLUSIONS

Despite the wide variety of professionally and recreationally induced peripheral nerve injuries, application of anatomic, physiologic and mechanistic considerations allow the neurologist to make an etiologic and localizing diagnosis.

Carpal tunnel syndrome and hand configuration

The likelihood that hand configuration is related to the development of carpal tunnel syndrome (CTS) was examined in this study. Based on neurophysiological criteria, 50 female subjects with CTS and 50 healthy female controls were selected and their external hand dimensions were measured. Our results showed that the palm length and third digit length were significantly shorter and the palm width larger in the subjects with CTS compared with controls. Regression analysis demonstrated that the hand ratio [(palm + third digit length)/palm width] was significantly correlated with median nerve conduction measurements. The hand ratio may be a simple and useful predictive measurement in determining the tendency for CTS.