Neuromuscular Diseases A Practical Guideline - part 4

137 Cauda equina Genetic testing NCV/EMG Laboratory Imaging Biopsy + ++ The conus medullaris terminates at vertebrum L1. The lower segmental ventral and dorsal lumbar and sacral nerve roots form the cauda equina. The lumbar nerve roots run obliquely downwards and laterally. The sacral spinal nerves divide into rami within the spinal canal. Each ramus passes through a pelvic sacral foramen to join the sacral plexus; each dorsal ramus emerges through a dorsal sacral foramen to supply paraspinal muscles and the skin over the sacral and medial gluteal areas. The cauda equina is loosely enveloped by arachnoid membrane, from which a sleeve extends to cover each nerve root. As a nerve passes into the nerve foramen it is invested in a short sleeve of dura. Acute central (disc) herniation: Pain bilaterally in the buttock, sacral, perineal, and posterior leg regions, and sphincter dysfunction. Anatomy Symptoms Chronic: Back pain, perineal pain, paresthesias. Urinary and erectile dysfunction may occur in men. Acute: Signs Weakness of S1 and S2 muscles, sensory loss from soles to perineal region with saddle anesthesia. Loss of anal wink. Roots positioned most laterally (lower lumbar and upper sacral) are most often affected, while the central roots can be spared (S3–S5). Thus, the bladder is often spared. Chronic: Similar signs as acute injury. Muscle wasting in chronic conditions may resemble chronic polyneuropathy. Toxic: Pathogenesis Anesthesia (spinal and epidural anesthesia) Contrast media Cytotoxic drugs (intrathecal methotrexate) Radiation: TRI (transient radicular irritation) Spinal arachnoiditis This is trial version www.adultpdf.com 138 Vascular: AV fistulas (spinal/dural) may mimic spinal stenosis Cauda equina claudication Spinal subarachnoid hemorrhage Infectious: AIDS: CMV infections Herpes simplex infection Others: cryptococcal, syphillis, tuberculosis Inflammatory/Immune: Bechterew’s disease Neoplastic: Ependymoma Neurofibroma Rare: dermoid, hemangioblastoma, lipoma, meningioma, paragangliomas, schwannoma Malignant disease: astrocytoma, bone tumors, leptomeningeal carcinomatosis, metastases, multiple myeloma Acute central disc protrusion: A large acute central disc may cause acute and dramatic bilateral sciatic pain. Also pain in the buttock and perineal regions, numbness and weakness of the legs, and sphincter dysfunction. “Saddle anesthesia”. Chronic central disc: Mimics tumors of the conus medullaris and is associated with perineal pain, paresthesias and urinary dysfunction. Trauma: Fractures of the sacrum Spinal surgery Vertebral injury Genetic: Tethered cord Diagnosis Differential diagnosis Therapy Imaging of bony structures and MRI. CSF in inflammatory conditions Electrophysiology: EMG of S1–S3 muscles Sensory conductions Reflex techniques (F waves, H reflex) Spincter EMG including bulbocavernosus reflex Magnetic stimulation Spinal cord (epiconus- medullary lesions) Rapidly ascending polyneuropathy Sensorimotor neuropathies with autonomic involvement Depends on the cause This is trial version www.adultpdf.com 139 Guigui P, Benoist M, Benoist C, et al (1998) Motor deficit in lumbar spinal stenosis: a retrospective study of a series of 50 patients. J Spinal Disord 11: 283–288 Hoffman HJ, Hendrick EB, Humphreys RB, et al (1976) The tethered spinal cord; its protean manifestation, diagnosis and surgical correction. Childs Brain 2: 145–155 Tyrell PNM, Davies AM, Evans N (1994) Neurological disturbances in ankylosing spondyli-tis. Ann Rheum Dis 53: 714–717 Yates DAH (1981) Spinal stenosis. J R Soc Med 74: 334–342 References This is trial version www.adultpdf.com 141 Mononeuropathies This is trial version www.adultpdf.com 143 Mononeuropathies are an essential part of clinical neurology. The clinical Introduction diagnosis depends on the knowledge of anatomy, the presentation of clinical syndromes and numerous etiologies. The individual mononeuropathies of the upper extremity, the trunk and the lower extremities are discussed by the anatomic course of the nerve , anomalies and their symptoms and signs. The most likely causes of damage are discussed and differential diagnosis is considered. Therapeutic aspects and if available prognosis are mentioned. The references are limited to a few key references. Most of our artist‘s illustrations are devoted to this section. The clinical photography should help the reader to identify the patient’s abnormalities. The concept is an accurate and brief description of the most important clinical features. The trunk nerves which are often neglected are summarized in a separate subsection. This is trial version www.adultpdf.com ... - tailieumienphi.vn